Method and system for scheduling positioning signal transmission and operating a self-positioning device

Abstract

The present disclosure relates to methods and systems for scheduling positioning signal transmissions and operating a self-positioning device. A positioning system and method are provided for transmitting time-stamped positioning signals from an anchor according to one or more transmission schedules. The transmission schedule can be generated and updated to achieve desired positioning performance. For example, one or more anchors can transmit positioning signals at a different rate than other anchors, the order of anchor transmissions can be changed, and the signals can partially overlap. In addition, different transmission parameters can be used to transmit two positioning signals simultaneously without interference. The self-positioning device is capable of receiving the positioning signals and determining its position. The self-positioning device can have a configurable receiver that can select to receive one of multiple available positioning signals. The self-positioning device can have a pair of receivers capable of receiving two positioning signals simultaneously. A bridging anchor can be provided to enable the self-positioning device to seamlessly switch between two positioning systems.

Description

[0001] This application is a divisional application of invention patent application 201680044509.3, entitled “Method and system for scheduling positioning signal transmission and operating a self-positioning device,” filed on May 30, 2016.

[0002] Cross-reference to related applications

[0003] This application claims the benefit of priority to U.S. Provisional Application No. 62 / 168,704, filed May 29, 2015, and U.S. Non-Provisional Application No. 15 / 063,104, filed March 7, 2016, both of which are incorporated herein by reference in their entireties. Technical Field

[0004] The present disclosure relates to the field of object positioning, positioning systems and methods using time-stamped signals such as ultra-wideband (UWB) signals, and operating self-positioning devices. Background Art

[0005] Logistics and industrial automation increasingly rely on precise positioning to support and control manual and automated processes, with applications ranging from “smart things” to efficient tracking and assistance solutions for robots such as automated guided vehicles (AGVs).

[0006] UWB technology has been promoted as a positioning solution for asset tracking applications. This application involves maintaining a centralized database of assets and their storage locations in warehouses, hospitals, or factories. When using UWB technology, assets such as pallets, assemblies, or even people can be equipped with tags that transmit UWB signals at regular intervals. UWB sensors installed in the warehouse, hospital, or factory can then detect these signals. A central server then uses the UWB signals detected by the sensors to calculate the tags' locations and update the centralized database.

[0007] Mobile robots are increasingly being used to facilitate task performance in both consumer and industrial settings. Autonomous mobile robots, in particular, offer benefits including: freeing workers from performing dangerous or remote tasks; high repeatability; and, in a growing number of cases, high performance. A significant challenge in the use of mobile robots in general, and autonomous mobile robots in particular, is robot localization, i.e., determining the robot's position in space. Current localization solutions are not well suited for many mobile robot applications, including those where the mobile robot operates in areas where positioning, such as that provided by Global Navigation Satellite Systems (GNSS), is unreliable or ineffective, or where operation near humans is required.

[0008] Current UWB positioning solutions for robot localization do not allow a mobile robot to directly determine its own position. Instead, a robot equipped with a tag would first transmit a UWB signal from its location. UWB sensors near the robot would then detect the signal and relay it to a central server. The central server would then calculate the mobile robot's position, which would then have to be transmitted back to the robot via a wireless link. This type of system architecture invariably introduces significant communication delays (e.g., latency) for controlling the mobile robot. This communication architecture also results in a relatively high risk of signal loss (e.g., due to wireless interference) and correspondingly low system robustness, making it unsuitable for many safety-critical robust applications (e.g., autonomous mobile robot operation). Furthermore, in this architecture, the maximum number of tags and the tag transmission rate (i.e., the update rate of the positioning system) are always linked, as multiple UWB signals currently do not overlap in these systems. This results in limited scalability for a given tag transmission rate (i.e., the system can only support a limited number of tags in parallel). Furthermore, if a higher tag transmission rate or redundancy is required, a smaller number of tags will need to be used. Furthermore, with such an architecture, the maximum update rate for determining the tag’s location is inversely proportional to the number of tags, making it unsuitable for tracking a large number of objects at a high update rate.

[0009] Another positioning system proposed in the prior art uses a mobile transceiver that communicates with a fixed transceiver through the bidirectional exchange of UWB signals. The bidirectional communication with the fixed transceiver enables the mobile transceiver to calculate the flight time between itself and the fixed transceiver. In this architecture, the communication between the mobile transceiver and the fixed transceiver must be coordinated so that the communications do not interfere. Knowing the flight time of three or more fixed transceivers enables each mobile transceiver to calculate its relative position in the environment using trilateration. Because each mobile transceiver communicates with each fixed transceiver, the system update rate is inversely proportional to the number of mobile transceivers and the number of fixed transceivers. This architecture is therefore not suitable for systems where a large number of objects must be located at a high frequency (e.g., tracking groups of robots where position measurements are used in the robot control loop to influence the robots' actions), systems where the location or identity of mobile transceivers should remain private (e.g., tracking people), systems that require both transceiver redundancy and high update frequencies (e.g., safety-critical applications such as vehicle positioning systems), or in multipath environments where a high update frequency and a large number of tracked objects are required (e.g., robotic warehouses) where the maximum number of transceivers is needed to help disambiguate multipath signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Embodiments of the present disclosure are illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar elements and in which:

[0011] Figure 1 is a block diagram of an illustrative positioning system according to some embodiments of the present disclosure;

[0012] Figure 2 is a block diagram of a self-positioning device and an exemplary transceiver of a positioning system according to some embodiments of the present disclosure;

[0013] Figure 3 is a detailed block diagram of an exemplary transceiver of a positioning system according to some embodiments of the present disclosure;

[0014] Figure 4 is a block diagram of an illustrative transceiver including a pair of a first transceiver and a second transceiver according to some embodiments of the present disclosure;

[0015] Figure 5 is a block diagram of an illustrative self-positioning device according to some embodiments of the present disclosure;

[0016] Figure 6 is a schematic timing diagram according to some embodiments of the present disclosure;

[0017] Figure 7 is a block diagram of an illustrative self-positioning device including a pair of first and second self-positioning devices according to some embodiments of the present disclosure;

[0018] Figure 8 is a block diagram of an illustrative self-positioning device including multiple optional antennas according to some embodiments of the present disclosure;

[0019] Figure 9 is a block diagram of an illustrative positioning unit including location update processing according to some embodiments of the present disclosure;

[0020] Figure 10 shows an illustrative mobile robot including a self-positioning device according to some embodiments of the present disclosure;

[0021] Figure 11 According to some embodiments of the present disclosure, Figure 10 A block diagram of a schematic control unit for use with a mobile robot;

[0022] Figure 12 shows an illustrative transceiver network having a large number of transceivers according to some embodiments of the present disclosure;

[0023] Figure 13 shows an illustrative simplified transceiver network according to some embodiments of the present disclosure;

[0024] Figure 14 shows an illustrative transceiver network with geographically adjacent cells according to some embodiments of the present disclosure;

[0025] Figure 15 shows an illustrative mobile robot operating in an area served by multiple transceiver cells according to some embodiments of the present disclosure;

[0026] Figure 16 shows an illustrative input parameter map that may be used to determine a schedule according to some embodiments of the present disclosure;

[0027] Figure 17 shows an illustrative dynamic positioning performance map for determining a schedule according to some embodiments of the present disclosure;

[0028] Figure 18 shows illustrative examples of how a schedule may be adjusted according to some embodiments of the present disclosure;

[0029] Figure 19 shows another illustrative example of how a schedule may be adjusted according to some embodiments of the present disclosure;

[0030] Figure 20 shows a schematic example of how scheduling may be adjusted for two groups of mobile robots according to some embodiments of the present disclosure;

[0031] Figure 21 is a diagram illustrating a schematic structure of a positioning signal according to some embodiments of the present disclosure;

[0032] Figure 22 shows an exemplary transmission schedule that can be used to achieve a higher positioning update rate according to some embodiments of the present disclosure;

[0033] Figure 23 According to some embodiments of the present disclosure, Figure 22 Part of the schematic transmission schedule and corresponding receiver activities;

[0034] Figure 24 shows a schematic transmission schedule of a positioning signal including two payloads according to some embodiments of the present disclosure;

[0035] Figure 25 shows an exemplary positioning system and corresponding performance map according to some embodiments of the present disclosure;

[0036] Figure 26 Shows some embodiments of the present disclosure with different performance Figure 1 Used Figure 25Schematic positioning system of

[0037] Figure 27 shows an exemplary positioning system and corresponding performance map according to some embodiments of the present disclosure;

[0038] Figure 28 Shows some embodiments of the present disclosure with different performance Figure 1 Used Figure 25 Schematic positioning system of

[0039] Figure 29 shows an exemplary transmission schedule of positioning signals according to some embodiments of the present disclosure;

[0040] Figure 30 shows another exemplary transmission schedule of a positioning signal according to some embodiments of the present disclosure;

[0041] Figure 31 A schematic flow chart illustrating logic that may be implemented on a self-locating device to configure its receiver according to some embodiments of the present disclosure;

[0042] Figure 32 shows an illustrative application of a performance map to indoor and outdoor environments according to some embodiments of the present disclosure;

[0043] Figure 33 Two exemplary positioning networks according to some embodiments of the present disclosure are shown;

[0044] Figure 34 is a block diagram of an illustrative bridging anchor according to some embodiments of the present disclosure; and

[0045] Figure 35 is a block diagram of another illustrative bridging anchor according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0046] According to the present disclosure, the limitations of current systems for positioning have been reduced or eliminated.In addition, the present disclosure provides various technical advantages over current positioning systems.

[0047] Technical advantages of certain embodiments of the present disclosure relate to locating objects in two-dimensional or three-dimensional space. For example, in embodiments where a self-localizing device is used to determine the position of a wheeled mobile robot, a transmission schedule can be optimized such that the transmission schedule takes into account the relative position of an anchor relative to the robot's operating area or current position, or such that the transmission schedule takes into account the robot's movement constraints (e.g., all possible positions in a 2D plane). Other technical advantages of certain embodiments can optimize the performance of the localization system for specific use cases or applications, either in real time or offline. For example, in certain embodiments, the transmission schedule can be dynamically reconfigured based on predetermined rules (e.g., based on comparing the estimated position of the self-localizing device to one or more predetermined positions, based on a time code, based on an attribute) or based on a request (e.g., an operator command).

[0048] Certain embodiments provide a technical advantage of improved positioning accuracy or precision. Certain embodiments provide a technical advantage of improved rates or latencies at which positioning information can be obtained or updated. For example, in certain embodiments, overlapping positioning signals can be used rather than interfering positioning signals to allow a self-positioning device to determine its position at a higher rate in a specific area or at a specific time. Certain embodiments provide a technical advantage of improved information content of positioning information. For example, in some embodiments, a self-positioning device can select to receive positioning signals such that particularly high uncertainties in its position estimate in a specific spatial direction or along a specific spatial axis are reduced.

[0049] Additional technical advantages of certain embodiments relate to receiving wireless signals, for example, used by a device to determine its own location. In some embodiments, reception of positioning signals is not degraded when direct line of sight between the receiving device and a sufficiently large number of signal transmitters cannot be established. For example, some embodiments allow operation in areas without good line of sight to a global navigation satellite system (GNSS) as well as indoors. In some embodiments, the signal is not distorted by multipath, does not suffer from the multipath fading observed in narrowband signals, or suffers from reduced signal quality in the absence of direct line of sight in indoor environments. For example, some embodiments do not exhibit performance degradation in enclosed environments (e.g., indoors), in forests, or in dense urban environments, such as those where maintaining track of GNSS signals becomes more difficult.

[0050] Technical advantages of some embodiments may allow multiple positioning signals to arrive at a receiver antenna with sufficient time intervals, avoiding attenuation of signal detection and degradation of positioning system performance even in the event of signal overlap.

[0051] The technical advantages of some embodiments are such that they can be used in real time and by an unlimited number of receivers to determine the two-dimensional or three-dimensional position of the receivers in a GPS-denied environment or any environment where greater accuracy or system redundancy or fail-safe operation can be desired.

[0052] The technical advantages of some embodiments may improve the performance of current mobile robots and allow new uses for mobile robots by enabling positioning with higher update rates, with lower latency, in larger spaces, or with higher accuracy than is currently possible, resulting in higher performance robot control.

[0053] Another technical advantage of some embodiments can allow a person, mobile robot, or other machine to be equipped with a self-positioning device that can determine its 3D position in space without transmitting a signal. This can improve positioning performance and allow new uses of positioning technology by providing regulatory advantages, allowing scalability (e.g., the system can be used in parallel by an unlimited number of self-positioning devices) or in arbitrarily large spaces, allowing higher redundancy (e.g., non-transmitting devices allow more transmitting anchors for a given network traffic load), enabling more efficient bandwidth usage (e.g., lower transmission, less interference), improving receiver energy efficiency (e.g., by not requiring energy for transmission), enhancing operational stealth, and enabling data to be used locally where it is needed, resulting in increased update rates, lower latency, higher speed, and higher system robustness.

[0054] Additional technical advantages of some embodiments may allow for improved system performance by fusing data from several sources, including one or more positioning networks (eg, UWB networks), readings of global properties from multiple locations, and onboard motion sensors.

[0055] Another technical advantage of some embodiments may be linked to providing a distributed positioning system. Such a system can provide improved robustness and safety of robotic operations because it does not rely on sensor signals from a single source. It can also provide good performance degradation by providing redundancy; can allow for identification and resolution of data inconsistencies by providing redundant data; and can provide higher performance by performing positioning based on comparisons of signals received from various transceivers.

[0056] Still further technical advantages of some embodiments allow positioning without direct line of sight between the transceiver and the self-locating device.Further technical advantages allow for lower sensitivity to disturbances from radio frequency traffic, secure communications, and improved resistance to interference, noise, and jamming.

[0057] For those skilled in the art, additional technical advantages will be apparent from the following description, drawings, and claims. Furthermore, although specific advantages have been listed above, various embodiments may include all, some, or none of the listed advantages. The listed advantages should not be considered essential to any embodiment.

[0058] The present disclosure uses time-tagged signals (sometimes referred to herein as "positioning signals"). Time-tagged signals are radio frequency (RF) signals, and each signal has characteristics that can be detected and accurately time-tagged. Examples of characteristics include signal peaks, signal leading edges, and signal preambles. Examples of time-tagged signals include RF signals with a distinct, well-defined, repeatable frequency increase over time or frequency decrease over time. Additional examples of time-tagged signals include signal bursts, signal chirps, or signal pulses. Additional examples of time-tagged signals include signals with characteristics suitable for phase correction or amplitude correction techniques (e.g., signals with codes having low autocorrelation values).

[0059] In some embodiments, the time-stamping signal is an "open loop" unidirectional radio frequency signal transmitted over a reception area. Examples include DCF77 time code signals, GPS P-code signals, and terrestrial trunked radio signals. In some embodiments, the apparatus is a non-emitting apparatus.

[0060] In some embodiments, the time-stamping signal uses a narrowband frequency. In some embodiments, a center frequency or carrier frequency in the ISM band is used. In some embodiments, a center frequency or carrier frequency in the 1-48 GHz range is used. In some embodiments, a center frequency or carrier frequency in the 2.4-12 GHz range is used. In some embodiments, a center frequency or carrier frequency in the 3.1-10.6 GHz range is used. In some embodiments, a higher frequency is used. Compared to wideband signals (e.g., ultra-wideband (UWB) signals), narrowband signals tend to be more susceptible to multipath fading. In narrowband signals, the signal duration is typically longer than the delay variance of the channel. In contrast, for UWB signals, the signal duration is typically less than the delay variance of the channel. For example, in a UWB system with a pulse duration of 2 nanoseconds, the pulse duration is significantly less than the channel delay variance. Therefore, signal components can be easily resolved, and UWB signals are robust to multipath fading.

[0061] In some embodiments, the signal capable of time stamping is a UWB signal. The UWB signal is extended over a large bandwidth. As used herein, a UWB signal is a signal extended over a bandwidth exceeding the smaller of 125 MHz or 5% of the arithmetic center frequency. In some embodiments, a UWB signal is a signal extended over a bandwidth exceeding the smaller of 250 MHz or 10% of the arithmetic center frequency. In some embodiments, a UWB signal is a signal extended over a bandwidth exceeding 375 MHz or 15% of the arithmetic center frequency. In some embodiments, a UWB signal is a signal extended over a bandwidth exceeding 500 MHz or 20% of the arithmetic center frequency. In some embodiments, a bandwidth in the range of 400-1200 MHz is used. In some embodiments, a bandwidth in the range of 10-5000 MHz is used. In some embodiments, a bandwidth in the range of 50-2000 MHz is used. In some embodiments, a bandwidth in the range of 80-1000 MHz is used. UWB technology allows the initial radio frequency (RF) signal to be expanded in the frequency domain, resulting in a signal with a wider bandwidth, typically wider than the frequency content of the initial signal. UWB technology is suitable for positioning systems because it can transmit very short duration pulses that can be used to very accurately measure the arrival time of the signal and thus allow for a wide range of applications. UWB signals can be advantageously used in positioning systems because they have the ability to pass through obstacles and can extend for hundreds of meters without interfering with conventional narrowband and carrier waves used in the same frequency band.

[0062] In some embodiments, the time-stampable signal can be measured to within 0.6 nanoseconds relative to a clock. In some embodiments, the arrival time of the time-stampable signal can be measured to within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 nanoseconds relative to a clock.

[0063] In some embodiments, the transmission rate is measured as a long-term average of the number of transmissions per second. In some other embodiments, the transmission rate is measured as the inverse of a long-term average of the time interval between two subsequent transmissions. In some embodiments, a typical interval is one of 1-500 microseconds, 1-1000 microseconds, 1-500 milliseconds, 1-1000 milliseconds, 1-5 seconds, 1-500 seconds, or any combination thereof. In some embodiments, no interval is used. In some embodiments, the long-term average is calculated over a window of 1-10 seconds. In some other embodiments, the long-term average is calculated over a window of 1-10 minutes. In some other embodiments, the long-term average is calculated over a window of 10 minutes.

[0064] In some embodiments, the average equivalent isotropically radiated power (EIRP) density of the signal is less than -40 dBm / MHz at all frequencies. In some embodiments, the average EIRP density of the signal is less than -80, -70, -60, -50, -30, -20, or -10 dBm / MHz at all frequencies.

[0065] In some embodiments, the maximum power of the transmitted signal is less than 0.1 mW per channel. In some embodiments, the maximum power of the transmitted signal is less than 1.0 mW per channel. In some embodiments, the maximum power of the transmitted signal is less than 100 mW per channel. In some embodiments, the maximum power of the transmitted signal is less than 500 mW per channel. In some embodiments, the maximum power of the transmitted signal is less than 10 W per channel.

[0066] In some embodiments, the smaller of the maximum power of the signal and the EIRP density of the signal is applied. In some embodiments, the larger of the maximum power of the signal and the EIRP density of the signal is applied. In some embodiments, one of the limits on the EIRP density of the signal and the limit on the maximum power of the signal are applied. In some embodiments, both the limits on the EIRP density of the signal and the limits on the maximum power of the signal are applied. In some embodiments, the limits apply to narrowband signals. In some embodiments, the limits apply to broadband signals.

[0067] In some embodiments, the typical effective range of the transceiver is between 1 meter and 50 meters. In some embodiments, the typical effective range of the transceiver is between 1 meter and 100 meters. In some embodiments, the typical effective range of the transceiver is between 1 meter and 500 meters. In some embodiments, the typical effective range of the transceiver is between 1 meter and 1000 meters. In some embodiments, the typical effective range of the transceiver is between 1 meter and 5000 meters. In some embodiments, the device may receive UWB signals only from a subset of the transceivers.

[0068] In some embodiments, a maximum data rate of 50 Mbps is used. In some embodiments, a maximum data rate of 5 Mbps is used. In some embodiments, a maximum data rate of 1 Mbps is used.

[0069] In some embodiments, a linear spread spectrum (CSS) signal is used. In some embodiments, a frequency modulated continuous wave (FMCW) signal is used.

[0070] Some embodiments include a positioning unit. In some embodiments, the positioning unit may calculate at least one of: (i) an orientation or orientation information, (ii) a position, or (iii) a motion from a positioning device.

[0071] In some embodiments, the positioning unit calculates the position of the self-locating device based on the reception time of the time-stamped signal and the known positions of the transceivers. In some embodiments, a time-of-arrival scheme is used. In some embodiments, a time-difference-of-arrival scheme is used. Multilateration requires the positioning unit to calculate the time difference between the reception times of two time-stamped signals. By subtracting the known time difference in the signal transmission times from the difference in their reception times (also known as a "TDOA measurement"), the positioning unit can calculate the difference in distance to the two transceivers from which the signals were transmitted (for example, because the signal from transceiver 2 is received 1 ns later than the signal from transceiver 1, transceiver 2 is 30 cm farther away than transceiver 1). By calculating the distance differences between multiple transceivers, the positioning unit can calculate the position of the self-locating device by solving a system of hyperbolic equations or a linearized version thereof. Methods for solving this system of equations are known to those skilled in the art and may include nonlinear least squares, least squares, Newton iteration, gradient descent, and the like. Multilateration methods require that the time difference in the signal transmission times be known.

[0072] In some embodiments, the positioning unit of a self-positioning device can iteratively calculate position. In some embodiments, the positioning unit iteratively updates the position estimate whenever a signal is received, without waiting for time-stampable signals to be received from all transceivers. In some embodiments, when a time-stampable signal is received, an adjustment to the current position estimate is calculated based on the difference between its reception time and the reception time of a previously received time-stampable signal. In some embodiments, known filtering methods (e.g., Kalman filtering, particle filtering) are used to calculate or apply this update. In some embodiments, the adjustment is calculated based on the variance of the current position estimate (e.g., if the current estimate is relatively accurate, less adjustment will be applied). In some embodiments, the adjustment is calculated based on the positions of the two transceivers from which the time-stampable signals were transmitted. In some embodiments, the adjustment is calculated based on a measurement model that describes the probability distribution of TDOA measurements based on the current position estimate and the positions of the two transceivers. In some embodiments, this allows more or less adjustment to be applied depending on how accurate the TDOA measurements are determined to be (e.g., if a first transceiver is on a line connecting the current position estimate and a second transceiver, the TDOA measurements obtained from both transceivers may be considered unreliable and therefore less adjustment applied).

[0073] In some embodiments, the positioning unit updates the position estimate based on a system model that describes the probability distribution of the position of the self-positioning device. In some embodiments, the system model can be based on other estimated states (e.g., the velocity or heading of the self-positioning device). In some embodiments, the system model can be based on input history (e.g., if the input command is likely to give movement in the positive x-direction based on system dynamics, then the new position estimate is more likely to be in the positive x-direction than in the negative x-direction).

[0074] In some embodiments, the system model can be based on measurements from sensors or global properties. In some embodiments, the positioning unit can calculate the position of the self-positioning device based on the global properties. In some embodiments, the positioning unit can calculate the position of the self-positioning device based on the difference between the global properties measured by the self-positioning device and the global properties measured by one or more transceivers (for example, if both the self-positioning device and the transceiver measure air pressure, then the relative altitude difference between the two can be calculated based on the known relationship between altitude and air pressure).

[0075] In some embodiments, the localization unit can use the history of position estimates and the system model to calculate other dynamic states of the subject, such as velocity or heading. For example, if the history of position estimates indicates motion, velocity can be estimated. As another example, if the history of position estimates indicates motion in the positive y-direction, and the system model indicates that only positive motion is possible (e.g., a skid-steer vehicle), then heading can be determined to be heading in the positive y-direction.

[0076] In some embodiments, the position is a one-dimensional position, a two-dimensional position, a three-dimensional position, or a six-dimensional position (ie, including position and orientation).

[0077] In some embodiments, the performance of a positioning unit (also referred to as localization performance or positioning performance) can be expressed as the average error of a position estimate. In some embodiments, positioning performance can be expressed as the variance of a position estimate. In some embodiments, positioning performance can be calculated based on a dilution of precision. In some embodiments, positioning performance can be calculated based on latency (e.g., the time required for a positioning unit to detect a change in position from a positioning device).

[0078] In some embodiments, the relative position calculated by the positioning unit is calculated with an accuracy of 1 meter, 20 cm, 10 cm, or 1 cm. In some embodiments, the time delay between receipt of the time-stamped signal and calculation of the updated position estimate provided by the positioning unit is less than 50 ms, 25 ms, 10 ms, 5 ms, 2 ms, or 1 ms. In some embodiments, the system update rate for full position updates or for partial position updates is greater than 1 Hz, 5 Hz, 10 Hz, 50 Hz, 250 Hz, 400 Hz, 800 Hz, 1000 Hz, or 2000 Hz.

[0079] In some embodiments, the positioning system includes at least 1, 2, 3, 5, 7, 10, 25, 50, 100, or 250 anchors. In some embodiments, the positioning system supports more than 1, 2, 3, 5, 10, 20, 40, 100, 200, 500, 1000, 5000, or 10,000 self-positioning devices.

[0080] As used herein, a clock refers to a circuit, structure, or device capable of providing a time measurement. The time measurement can be in any suitable unit of time. For example, the time measurement can be based on the fundamental unit of seconds. As another example, the time measurement can be based on a count that increments at a specific rate. In some embodiments, the clock includes an internal oscillator for determining the time measurement. In some embodiments, the clock determines the time measurement based on a received signal (e.g., from an external oscillator). In some embodiments, a clock interface provides a clock signal.

[0081] In some embodiments, each transceiver can use its own onboard clock. In some embodiments, a single clock can generate a clock signal that is transmitted to each transceiver via a cable or wirelessly. In some embodiments, the clock signal can rely on at least one one-time code transmitted by a radio transmitter, or on at least one of a terrestrial radio clock signal, a GPS clock signal, and a time standard. In some embodiments, the clock signal can be based on a GPS-compliant oscillator, a transmitter, or a time estimate calculated from at least two clocks to improve the accuracy or long-term stability of the clock signal.

[0082] The clock can, for example, use a crystal oscillator or a temperature-compensated crystal. In some embodiments, enhanced clock accuracy can be achieved through temperature stabilization via an oven-controlled crystal oscillator (OCXO), analog (TCXO), or digital / microcontroller (MCXO) compensation. In some embodiments, a centralized synchronization unit is used. In some embodiments, an atomic oscillator (e.g., rubidium) is used as the clock.

[0083] In some embodiments, the clock is configured to have a maximum of (1x10 -8 ) 2 or (1x10 -9 ) 2 or (5x10 -10 ) 2 The Allan variance for the mean intervals between 5 ms and 10 ms or for the mean intervals between 5 ms and 100 ms or for the mean intervals between 1 ms and 1 s.

[0084] The device or transceiver may be equipped with analog and digital receive electronics. The receive electronics amplify the received signal and convert it to a baseband signal, which can then be demodulated and passed to central processing electronics. A key design aspect of the receiver is minimizing noise and distortion. This can be achieved by carefully selecting the components of the receive electronics (particularly the amplifier) ​​and optimizing the receiver's circuit design accordingly.

[0085] In some embodiments, the self-locating device or the antenna, analog receiving electronics, and digital receiving electronics of the self-locating device are configured to receive two time-stamped signals within a time window of 2, 10, or 50 seconds, wherein the time difference between the time stamps of the two UWB signals is within 0.6, 3, or 15 nanoseconds of the time difference between their actual reception times at the antenna of the device relative to the device's clock. As used herein, the terms "receiver" and "receive electronics" refer to the antenna, analog receiving electronics, and digital receiving electronics that receive the signal.

[0086] In some embodiments, the digital receive electronics of the device are further operable to time stamp received UWB signals with reference to a clock of the device to within less than 1 millisecond, 100 microseconds, or 10 microseconds.

[0087] The device or transceiver may be equipped with analog and digital transmission electronics.

[0088] In some embodiments, the transceiver, or the digital transmit electronics, analog transmit electronics, and antenna of the transceiver, is configured to transmit two time-stampable signals within a time window of 2 seconds, 10 seconds, or 50 seconds, or is configured such that: the time difference between the transmission of the two time-stampable signals from the transceiver's antenna is within 0.6 nanoseconds, 3 nanoseconds, or 15 nanoseconds of the time difference between their scheduled transmission times, with reference to the transceiver's clock. The terms "transmitter" and "transmit electronics" as used herein refer to the antenna, analog transmit electronics, and digital transmit electronics used to generate the signals.

[0089] In some embodiments, the scheduling unit is used to schedule signal transmission times. It is clear to those skilled in the art that any error in the transmission schedule caused by the transceiver will affect the accuracy of the position calculated by the positioning unit.

[0090] In some embodiments, the scheduled time refers to the time when the first pulse of the signal leaves the antenna of the transceiver. In some embodiments, the scheduled time refers to the start of a start of frame delimiter (i.e., the point when the transmitted signal changes from repeated transmission of the preamble to the transmission of the start of frame delimiter). In some embodiments, the apparatus is configured to compare two time-stampable signals transmitted by the same transceiver.

[0091] In some embodiments, the transceivers coordinate their transmissions at the packet level. In some embodiments, signal overlap is avoided. In some embodiments, the signals are transmitted: in a polling manner; at fixed intervals; in a specific time sequence; or sequentially. In some embodiments, the transceivers transmit signals simultaneously. In some embodiments, the transceivers transmit signals that partially overlap.

[0092] In some embodiments, each of the three or more transceivers includes a scheduling unit. In some embodiments, a single scheduling unit is operably coupled to the three or more transceivers. In some embodiments, this operably coupled connection is a wired connection. In some embodiments, this operably coupled connection is a wireless connection. In some embodiments, this wireless operably coupled connection is implemented using a signal such as a UWB signal. In some embodiments, the scheduling unit uses an update rate that is lower than the positioning signal rate.

[0093] In some embodiments, the scheduling unit is operable to ensure that there is a time separation of at least 5 microseconds, 10 microseconds, or 50 microseconds between the termination of one transceiver's transmission and the start of a different transceiver's transmission. In some embodiments, the scheduling unit is operable to monitor the positioning signal. In some embodiments, the scheduling unit is operable to calculate an improved schedule. In some embodiments, the scheduling unit is operable to ensure that there is a time separation of at least 1 microsecond, 5 microseconds, or 10 microseconds between the end of one signal and the start of a second signal transmitted by the same transceiver. In some embodiments, the scheduling unit is operable to maintain a memory of the assignment of medium access control addresses and scheduled transmission times.

[0094] In some embodiments, each of the three or more transceivers comprises a sensor. In some embodiments, the sensor is physically and operatively coupled to the transceiver. In some embodiments, the sensor is operable to provide data representing the orientation, position, or movement of the transceiver. In some embodiments, the sensor is configured to detect a disturbance in the position or orientation of the transceiver. In some embodiments, the sensor signal is a signal from a sensor physically coupled to the transmitter, wherein the sensor signal is transmitted as part of the payload of a signal, such as a UWB positioning signal.

[0095] In some embodiments, the self-positioning device includes a sensor that is physically and operatively coupled to the device and operable to provide data indicative of the orientation of the device. In some embodiments, the sensor is operable to provide data indicative of the orientation, position, or movement of the device. In some embodiments, the sensor is configured to provide data indicative of the orientation of an antenna of the self-positioning device.

[0096] Data from the sensors can be processed by a positioning unit or a position calibration unit. For example, data associated with a landmark can be compared with other data (e.g., data associated with another landmark, data from a memory device, sensor data, data representing a location) to improve the position estimate or the position calibration unit. As another example, a comparison between the position of a landmark relative to a transceiver detected by a first camera and the position of the same landmark relative to a self-positioning device detected by a second camera can allow the positioning unit to improve the position estimate. The comparison can use data associated with one or more landmarks. The comparison can also use data associated with observations made by one or more visual sensors.

[0097] Typical examples of sensors that may be beneficially used as part of the present disclosure include optical sensors, accelerometers, magnetometers, and gyroscopes.

[0098] In some embodiments, microelectromechanical systems (MEMS) or piezoelectric systems can be used to achieve the operational characteristics outlined in this disclosure. Examples of such microsensors that can be beneficially used with this disclosure include MEMS gyroscopes, MEMS accelerometers, piezoelectric gyroscopes, and piezoelectric accelerometers. In some embodiments, the use of microsensors enables the use of one or more inertial measurement units (IMUs), each of which can combine multiple gyroscopes or accelerometers within each subsystem, or utilize multi-axis gyroscopes or accelerometers. In some embodiments, this choice of microsensor enables the creation or use of self-positioning devices suitable for highly dynamic movement, requiring low weight and low power consumption while also requiring high performance. For example, a 3-axis MEMS gyroscope can be used to monitor the attitude of a self-positioning device and trigger a signal if an attitude threshold is exceeded. As another example, a MEMS gyroscope can be used to control a small flying robot equipped with a self-positioning device while hovering nearby, despite its low time constant. Examples of optical sensors include infrared sensors, linear cameras, optical flow sensors, and imaging sensors.

[0099] Some embodiments include a global property sensor, ie, a sensor operable to provide data representative of a global property.

[0100] Examples of global attributes include fields that have determinable values ​​at multiple or every point in an area, such as gravity, electromagnetic force, hydraulic pressure, and air pressure. Further examples of global attributes include radio frequency signal strength, global positioning system (GPS) signals, the earth's magnetic field, the earth's gravitational field, air pressure, landmarks, and radio time signals (such as the radio time signal transmitted by a DCF77 time code transmitter). Examples of landmarks include the horizon, the sun, moon, or stars, mountains, buildings, and prominent environmental features. Prominent environmental features can include unique natural features such as mountains, unique architecture such as monuments, and other environmental features such as those used in simultaneous localization and mapping (SLAM). Further examples of landmarks include those used in scale-invariant feature transform (SIFT) and speeded-up robust features (SURF). Note that in this disclosure, GPS or GNSS may be used as placeholders to describe any similar signals generated by other global navigation satellite systems such as, for example, GLONASS, Galileo, IRNSS, or BeiDou-2, and their improved versions (e.g., Real-Time Kinematic (RTK) GPS or DGPS).

[0101] In some embodiments, the device and the transceiver are both configured to detect the same global attribute. In some embodiments, the transceiver is configured to transmit data representing the global attribute at the location of the transceiver to the device or another transceiver, and the device or another transceiver is configured to compare the data with data representing the same global attribute at the location of the device or another transceiver. In some embodiments, the global attribute can be associated with a global attribute model.

[0102] In some embodiments, the global property sensor is a direction sensor. This direction sensor enables the transceiver to measure its orientation relative to a common reference frame shared by the transceiver and the self-positioning device. The transceiver can then transmit a signal indicating the transceiver's orientation, which is included as data (payload) in the positioning signal. In some embodiments, the transceiver can measure its orientation and transmit this orientation as the payload of the positioning signal.

[0103] In some embodiments, the position calibration unit can calculate an estimate of the transceiver's position. In some embodiments, the transceiver position is calculated once (e.g., as part of a calibration routine during the setup of the positioning system). In some embodiments, the transceiver position is calculated continuously (e.g., each time new data related to the transceiver's position becomes available). In some embodiments, the transceiver position unit is initialized using known, partially known, estimated, or partially estimated position information (e.g., an initial transceiver distance, position, or heading may be manually measured or entered).

[0104] Position calibration can be implemented in various ways. For example, the position calibration unit can calculate the position of the transceiver based on time-stamped signals received from other transceivers with known positions. This can allow, for example, additional transceivers to be added to an existing transceiver network. In some embodiments, the position calibration unit operates similarly to the positioning unit, or vice versa. In some embodiments, the position calibration unit is operably coupled to the compensation unit.

[0105] In some embodiments, a single position calibration unit can be used to calculate the positions of multiple transceivers relative to each other. This can, for example, allow initialization of a network of transceivers that do not yet have known positions. In some embodiments, multiple position calibration units are used (e.g., one per transceiver).

[0106] In some embodiments, the position calibration unit is implemented offboard the transceiver. For example, the position calibration unit can be implemented on a laptop computer connected to the transceiver using a cable. This can allow for a more convenient interface for the operator, for example.

[0107] In some embodiments, the synchronization unit is operable to synchronize at least one of (i) an offset of the first clock and (ii) a rate of the first clock based on a second clock. In some embodiments, the correction is calculated or the synchronization is performed based on at least one of an average, a median, and a statistical property of the clocks of a plurality of positioning systems. In some embodiments, a global attribute is used that also provides timing information, such as that provided by GPS, DCF 77, and other systems. In some embodiments, the synchronization unit uses a global attribute that also provides timing information.

[0108] In some embodiments, the synchronization unit is operable to explicitly or implicitly account for timing errors introduced by at least one of: (i) a first difference between a rate of the device clock and a rate of a clock of a first communication transceiver; and (ii) a second difference between a rate of the device clock and a rate of a clock of a different second communication transceiver.

[0109] In some embodiments, the synchronization unit is operable to perform synchronization or calculate a clock correction based on the compensation calculated by the compensation unit or data stored in the memory.

[0110] In some embodiments, the synchronization unit is operable to synchronize the onboard clock rate such that the statistical mean error between the onboard clock rate and the median of the onboard clock rates of two other transceivers is less than 10 parts per million, 1 part per million, or 100 parts per billion. In some embodiments, the synchronization unit is operable to synchronize the offset of the onboard clock such that the statistical mean error between the offset of the onboard clock and the median of the onboard clock offsets of the two other transceivers is less than 10 nanoseconds, 5 nanoseconds, 1 nanosecond, or 10 picoseconds. In some embodiments, this is achieved by explicitly or implicitly accounting for timing errors introduced by one or more of the transceiver's antenna and the transceiver's analog and digital transmit electronics, or by calculating a clock correction for the onboard clock offset based on a time-stamped UWB clock synchronization signal and data provided by a memory unit of the transceiver, or by changing the clock rate (e.g., by changing the clock's voltage, temperature, or crystal trimming).

[0111] In some embodiments, the compensation unit is used to correct for signal delay.The compensation unit calculates compensation for the effect on the time-stampable signal from the moment the transmission time of the signal is scheduled at the transceiver to the moment the signal is time-stamped at the receiving electronics of the transceiver or device.

[0112] Compensation is typically achieved by correcting receive timestamps or correcting transmit time information (e.g., transmit timestamps included as payload in the UWB data), for example, based on signal quality or group delay. The corrections can be calculated and applied immediately (e.g., by calculating corrections for individual timestamps or modifying individual timestamps) or in batches (e.g., by calculating corrections for timestamps in batches or modifying them in batches). Compensation can use several data sources to determine the required corrections; examples of data sources include (i) data representing the position and orientation of the transceiver and device; (ii) data provided by onboard sensors; (iii) data stored in memory; (iv) data provided by a synchronization unit; and (v) quality metrics provided by digital receive electronics.

[0113] In some embodiments, the compensation unit compensates for the effects of the position, orientation, or movement of the device's antenna relative to the transceiver's antenna. In some embodiments, the compensation unit compensates for the effects of obstacles. In some embodiments, the compensation is performed by calculating: (i) a corrected data representation of the distance, time, or duration, (ii) a corrected data representation of a comparison of a first and a second distance, time, or duration, or (iii) a corrected data representation of a comparison of multiple distances, times, or durations. In some embodiments, the corrected data representation is provided to the positioning unit.

[0114] In some embodiments, the compensation unit can also take into account the effects of the relative orientation, direction, and distance of the device's antenna relative to the transceiver's antenna. This is important due to the difficulty of creating omnidirectional antennas for time-stamped signals such as UWB signals. It is also important because some devices, depending on their spatial location relative to the transceiver or the communications architecture used, may be receiving signals from a large number of transceivers, receiving signals at a higher update rate, or receiving signals of higher quality than others. The corresponding values ​​associated with the calculation of the compensation values ​​can be determined as part of a calibration routine or during use (e.g., provided by the operator) and can be refined using assumptions (e.g., radial symmetry) or using data from other system components as described above. These values ​​can then be stored in memory for use, for example as a lookup table of compensation values ​​for different pairwise combinations of relative antenna orientation, direction, and distance.

[0115] Similar strategies to those outlined above for the compensation unit and the time-stampable signal may also be used by the synchronization unit or for the clock synchronization signal.

[0116] It should be understood that while compensation and aspects thereof are sometimes explained with respect to signals traveling between a device and a transceiver, the explanations may be equally valid and may be similarly used with respect to signals traveling between two devices or between two transceivers.

[0117] The control unit is used to generate control signals for the actuators based on data received from the positioning unit (eg position estimate) or sensors (eg onboard sensors) or global properties (eg atmospheric pressure).

[0118] The control unit may implement a control law that is well established or widely used in the prior art. Examples of such control laws include PID control; model predictive control; sliding mode control; full state feedback; and backoff control. Depending on the control law, the control unit may use the state estimate provided by the positioning unit.

[0119] The control unit can calculate control signals for a single actuator. In some embodiments, the control unit calculates different sets of control signals for different sets of actuators. For example, the control unit can calculate a first set of control signals for two actuators of a first module or a first axis of a robot, or a second set of control signals for a second module or a second axis of a robot.

[0120] Actuators can belong to the group of electronic, magnetic, and mechanical motors that move or control a mechanism or system. Examples include piezoelectric actuators, brushless motors, and servo motors.

[0121] In some embodiments, the actuator of a device is configured to move the device in three translational degrees of freedom. In some embodiments, the actuator is configured to move the device in three rotational degrees of freedom. In some embodiments, the actuator is configured to move a portion of the device, such as an antenna. In some embodiments, multiple actuators are used in combination.

[0122] In some embodiments, the actuator of the device is configured to move the position of the device by at least 30 cm. In some embodiments, the actuator of the device is configured to move the position of the device by at least 100 cm. In some embodiments, the actuator of the device is configured to move the rotation of the device by at least 30 degrees. In some embodiments, the actuator of the device is configured to move the rotation of the device by at least 90 degrees.

[0123] Figure 1FIG1 is a block diagram of an illustrative positioning system 100 (sometimes referred to herein as a "network"), including components involved in generating and executing a schedule for transmitting positioning signals, according to some embodiments of the present disclosure. System 100 includes a scheduler 110, a scheduling unit controller 120, and a transceiver 130 (also referred to herein as an "anchor").

[0124] The scheduler 110 uses one or more input parameters to determine the schedule. As shown, the input parameters may include one or more user requirements, anchor locations, and anchor properties. User requirements may include desired positioning performance. For example, a user may specify a minimum positioning performance within a positioning area. As another example, a user may specify different positioning performances within a positioning area. In some embodiments, the positioning performance may be input via a two-dimensional or three-dimensional map, where subareas within the positioning area are labeled with the desired positioning performance. The anchor location may be input based on a known coordinate system. In some embodiments, the user may input the anchor location. In some embodiments, the positioning system 100 may be configured to determine the location of the anchor using positioning signals. Anchor properties may include the connectivity of the anchors to each other and other anchor properties, such as available configurations (e.g., whether the anchor can receive and transmit simultaneously), the frequency at which the anchor can be set, antenna radiation patterns, any other suitable anchor properties, and any combination thereof.

[0125] Scheduler 110 may include one or more inputs, such as a communication input or user input for receiving input parameters. User inputs may include, for example, a keyboard, mouse, touchscreen, buttons, switches, touchpad, or any other suitable user input device. Communication inputs may include, for example, a wired interface (e.g., using USB, RS-232, Ethernet, or other standards) or a wireless interface (e.g., using Wi-Fi, IR, WiMAX, Bluetooth, or other standards). Scheduler 110 may also include a processor and memory. The processor may be adapted to execute computer program instructions stored in the memory, which may include an operating system and one or more applications, as part of performing the functionality described herein. For example, the processor may be configured to receive one or more input parameters, process the one or more inputs, and determine an appropriate schedule as explained in more detail below. Scheduler 110 may also include an output for outputting a schedule to an anchor (such as transceiver 130). In some embodiments, the schedule is first output to scheduling unit controller 120. This output may include, for example, a wired interface or a wireless interface. In some embodiments, the output may be the same as the communication input. In some embodiments, scheduler 110 may be implemented as a personal computer.

[0126] The scheduling unit controller 120 facilitates the transmission of schedules to anchors. In some embodiments, the scheduling unit controller 120 may communicate with one or more anchors (such as transceiver 130). In some embodiments, the scheduling unit controller 120 may process schedules received from the scheduler 110. For example, the scheduling unit controller 120 may prepare the schedule for transmission to the anchors. In one embodiment, this processing includes transforming the schedule and preparing it for transmission to the anchors. This may involve parsing the schedule file format (e.g., an XML or YAML file), converting the data in the file to a scheduling unit-specific format, adding information such as a unique schedule ID, serializing the data, and adding data protection information such as a CRC. The scheduling unit controller 120 may transmit the schedule (e.g., in its transformed format) to an anchor such as the transceiver 130. In some embodiments, the transmission is performed using the same type of wireless signal commonly used for positioning purposes. In this case, the scheduling unit controller 120 includes digital transmission electronics, analog transmission electronics, and an antenna. These components are described in more detail below. In some embodiments, the transmission is performed via separate wireless transmission channels or wired interfaces available to both the scheduling unit controller 120 and the anchors.

[0127] The dispatch unit controller 120 is shown as a separate component in the positioning system 100. However, it will be understood that this is merely illustrative. In some embodiments, the dispatch unit controller 120 or the functionality of the dispatch unit controller 12 may be integrated into other components. For example, the dispatch unit controller 120 may be integrated into the dispatcher 110. As another example, the dispatch unit controller 120 may be integrated into one or more anchors, such as the transceiver 130.

[0128] As described above, the positioning system 100 may include a transceiver 130. The transceiver 130 is configured to receive a schedule from the scheduling unit controller 120. Each transceiver 130 may receive a schedule from the scheduling unit controller 120 directly or indirectly through one or more other transceivers. The received schedule may be stored in a memory within each transceiver, from which the scheduling unit of each transceiver may access it. Details of the transceiver 130 are described below.

[0129] In some embodiments, transceiver 130 is capable of switching between different schedules. This can be achieved by including several scheduling units in each transceiver, or by using a single scheduling unit configured to receive a signal that causes the scheduling unit to switch to a different schedule. Several schedules can be received from the scheduling unit controller 120, including, for example, unique identifiers that allow the scheduling unit to determine which schedule to use based on the received signal. In some embodiments, the received signal can cause the scheduling unit to interrupt the current schedule, restart the current schedule, or jump to a specific point in the schedule. In some embodiments, the first portion of the long-term schedule can be designed to facilitate clock synchronization between network transceivers, while the second portion can be designed to optimize positioning performance. When the network synchronization error increases above a certain threshold, the scheduling unit controller can send a signal to restart the schedule. In other embodiments, each time a self-locating device enters a spatial area covered by the network of transceivers, the schedule execution may need to be restarted from the beginning or from a certain point in time. In some embodiments, the point in time at which the schedule execution is restarted may depend on the location at which the self-locating device enters the spatial area. In some embodiments, a default schedule (e.g., a schedule based on the ALOHA protocol) may be permanently stored in the transceiver's memory, and additional schedules may be transmitted by the scheduling unit controller 120. The transceiver may then operate in a default mode (based on the default schedule) or in a performance improvement mode (e.g., based on an optimized schedule received from the scheduling unit controller 120).

[0130] Figure 2 is a block diagram of three illustrative transceivers 130 and two self-positioning devices 140 of an illustrative positioning system 100 according to some embodiments of the present disclosure. In some embodiments, Figure 2 Positioning system 100 with Figure 1 The same positioning system 100. In some embodiments, Figure 2 The positioning system 100 is with Figure 1 The positioning system 100 shown is different from the positioning system. Each of the three transceivers 130 transmits a time-stamped positioning signal 202. In some embodiments, the three fixed transceivers 130 have known relative positions with respect to each other. In some embodiments, the three transceivers 130 have synchronized clocks 210. The transceivers are sometimes referred to herein as "anchors" or "beacons." It should be understood that although Figure 2 While three transceivers and two self-positioning devices are shown in FIG, any suitable number of transceivers and self-positioning devices may be used in the positioning system 100.

[0131] Figure 2Each transceiver 130 includes analog electronics 214 and digital electronics 216. Antenna 212 is coupled to analog transmission electronics 214. Analog transmission electronics 214 can generate an analog transmission signal from at least one digital data packet. The digital data packet is provided by digital transmission electronics 216. The analog transmission signal can be generated using an analog pulse generator. The analog transmission signal can also be amplified by an amplifier before being passed to antenna 212 for transmission.

[0132] exist Figure 2 In the embodiment of the present invention, transmission electronics 214, 216 are used to convert payload data (sometimes referred to as "payload") into a signal 202 that can then be transmitted by transmitter 130. In some embodiments, signal 202 is a UWB signal. A single UWB signal 202 transmitted by a single transceiver 130 can be received by multiple devices 140. Each device can use the information obtained from multiple signals 202 to calculate its position without transmitting its own signal.

[0133] Clock 210 is coupled to transmission electronics 214, 216 and provides timing information for transmission signal 202. Clock 210 may include an onboard clock, or may have a wireless or wired connection (not shown) that receives time information from, for example, an off-board clock (not shown) at a remote location.

[0134] The transmissions from the three transceivers 130 (e.g., signal 202) can be coordinated using a scheduling unit 218, which is operable to schedule the transmission of signal 202. In some embodiments, the scheduling unit 218 can provide sufficient time intervals between positioning signals to prevent transceiver messages from reaching the receiver's antenna without sufficient time intervals (which can result in poor signal detection and, therefore, reduced performance of the positioning system 100). In some embodiments, the scheduling unit 218 can implement an ALOHA protocol to reduce or prevent the consequences of insufficient time intervals. In some embodiments, signal transmissions can follow a pre-programmed schedule, or scheduling can be performed centrally, such as Figure 1 In some embodiments, the scheduling unit may be configured to transmit a schedule to each transceiver as described in [1]. In some embodiments, scheduling may be performed by each transceiver. For example, scheduling for a transceiver may be based on information stored by the transceiver about other transceivers (e.g., an ordered list of other transceivers in range or a transmission schedule). In some embodiments, the scheduling unit may further provide configuration signals to the transmission electronics. These configuration signals may be interpreted by the transmission electronics to adjust certain transmitter settings, such as center frequency, signal bandwidth, preamble, preamble length, transmission power, or antenna.

[0135] Analog transmission electronics 214 is coupled to digital transmission electronics 216, and together they enable transmission of UWB signal 202. Such transmission can be performed so that transmission of signal 202 from antenna 212 occurs precisely at a designated transmission time relative to clock 210. This can be achieved using digital transmission electronics 216. Digital transmission electronics 216 can coordinate its operation with scheduling unit 218. Signal transmission at a designated time is preferably performed so that a specific symbol is transmitted from antenna 212 at a designated time. For transmissions compliant with the IEEE 802.15.4 standard, a common choice for the time at which a symbol is transmitted is the beginning of the start-of-frame delimiter (SOD), i.e., the point at which the transmitted signal changes from repeated transmissions of the preamble to transmissions of the SOD. In this transmission at a designated time, digital transmission electronics 216 can use the signal provided by clock 210 as a reference; transmission times can therefore be expressed relative to this clock.

[0136] Figure 2 The two self-positioning devices 140 shown in FIG. 1 are each configured to receive a UWB radio signal 202 transmitted by the transceiver 130 .

[0137] Figure 3 is a detailed block diagram of an illustrative transceiver 130 according to some embodiments of the present disclosure. In some embodiments, Figure 3 The transceiver 130 is used in Figure 1 Positioning system 100 or Figure 2 In some embodiments, Figure 3 The transceiver 130 is different from Figure 1 and Figure 2 The positioning system is used together with the positioning system depicted in .

[0138] Figure 3 Each of the transceivers 130 may include an antenna 212 coupled to analog transmit electronics 214 and analog receive electronics 220. In some embodiments, a TX / RX switch is used to connect the antenna to one or the other of the electronics 214, 220. The analog receive electronics 220 is coupled to the digital receive electronics 222, and together they allow for reception of signals 302 transmitted by the other transceiver 130. The analog and digital receive electronics 220, 222 may have the same Figure 2The analog and digital receive electronics 220, 222 may have capabilities similar to those of the electronics on the self-locating device 130. For example, the analog and digital receive electronics 220, 222 may convert the signal 302 into data (payload), accurately determine the time at which the transmitted signal arrives at the antenna 212, and may provide additional quality metrics related to the received signal 302, such as signal strength, reception time standard deviation, and metrics for determining whether the signal is traveling in line of sight, etc.

[0139] Digital receive electronics 222 are operably coupled to a synchronization unit 224, which can be used to identify and compensate for any transceiver's clock 210 that is not fully synchronized with the clocks of the other transceivers. Upon receiving a UWB radio signal, the received data, time stamp, and quality metrics are sent to synchronization unit 224. Synchronization unit 224 can compare the received time stamp with previous received time stamps, transmission time information included in the signal's data (payload), and transmission time information included in the previous signal 202. Based on this information, synchronization unit 224 can calculate the current behavior of clock 210, such as its current clock rate or the current rate of change in the current clock rate. Additionally, synchronization unit 224 can determine the signal flight time between fixed transceivers by evaluating the differences between locally measured receive time stamps, locally set transmission times, measured receive time stamps reported from other transceivers, and the set transmission times of the other transceivers. By carefully correcting for errors such as different clock offsets, clock rates, and signal propagation times, synchronization unit 224 can calculate corrections to allow the transceivers to obtain a common, synchronized reference time. In some embodiments, synchronization uses signals 302 received from other transceivers 130. Time synchronization between transceivers is beneficial, for example, because any offset in transceiver timing may translate into errors in the positioning of the self-positioning device.

[0140] Figure 3 The transceiver 130 may also include a sensor 226 and a global property sensor 228. Both sensors are coupled to the digital transmission electronics 216. This enables signals representing measurements made by the sensor 226 and the global property sensor 228 to be included in the data transmitted by the digital transmission electronics 216, the analog transmission electronics 214, and the antenna 212 in the form of the positioning signal 202.

[0141] In some embodiments, sensor 226 or global property sensor 228 may be used to sense the orientation of the transceiver. Knowing the orientation of the transceiver, a self-positioning device (e.g., Figure 2The self-positioning device 140 may be able to compensate for the signal delay introduced by the orientation of the transceiver's antenna 212 relative to the self-positioning device's antenna. This may be achieved, for example, by transmitting the transceiver's detected orientation as part of its transmitted positioning signal.

[0142] Each transceiver 130 can be equipped with a memory 230, which can be used to store data such as configuration data, desired signal amplification, synchronization data (e.g., clock offset or rate correction), or range accuracy calibration data. Memory 230 can also be used to buffer data after reception and before transmission. In some embodiments, memory 230 can be rewritten multiple times or is non-volatile memory. In some embodiments, memory 230 is used to store one or more transmission schedules.

[0143] Figure 3 An illustrative transceiver (sometimes referred to herein as a "wireless transceiver" or "wireless UWB transceiver") is shown that can receive and process wireless signals from other transceivers. This is accomplished by transceiver 130 having analog receive electronics 220 and digital receive electronics 222, which are operable to receive signals transmitted by other transceivers 130.

[0144] The first transceiver 130 may use one or more signals 302 from the second transceiver 130 or from a plurality of other transceivers 130 to adjust its transmission schedule, for example to provide better time intervals between transmissions. This may be accomplished, for example, by the scheduling unit 218 receiving a signal from the network (e.g., Figure 2 This is achieved by storing the times at which signal 302 is received by other transceivers 130 in network 100 in memory 230 and subsequently adjusting the local transmission schedule based on these times. In some embodiments, the improved time interval between transmissions results in reduced interference between positioning signal 202 and signal 302. In some embodiments, measuring the time interval between positioning signals 202 can be a metric used for evaluation or improvement of the performance of a positioning network.

[0145] In some embodiments, a transceiver 130 may use signal 302 to indicate the occurrence of an event. In some embodiments, signal 302 may be used by a transceiver 130 to trigger an action by another transceiver 130. In some embodiments, the action results in a change in the scheduling or transmission schedule of the positioning signal 202. In some embodiments, a dynamic transmission schedule may be used to react to the addition or removal of transceivers from the system. In some embodiments, the positioning network (e.g., Figure 2 The reaction of the network 100) to the addition or removal of transceivers (eg, due to failures) can be used as a metric to assess the robustness of the network.

[0146] In some embodiments, signal 302 may be the same type of signal used by the self-locating device (e.g., signal 202). In some embodiments, signal 302 may differ in some way from signal 202. For example, signal 302 may have a different payload. In some embodiments, signal 302 may be transmitted at a different time than signal 202. For example, signal 302 may be transmitted during installation or during the calibration phase of the positioning system, while signal 202 may be transmitted during system operation. Signals 302 and 202 may also differ in other ways (e.g., their signal strength, preamble, etc.). In some embodiments, signal 202 and signal 302 may be used differently. For example, the transceiver may transmit signal 202 at a different update rate than that used by signal 302, or the signal transmissions may follow a different schedule.

[0147] Figure 4 FIG1 is a block diagram of an illustrative transceiver including a pair of first and second transceivers 130a, 130b according to some embodiments of the present disclosure. The transceivers 130a, 130b are physically coupled together using a structural element 400. Each transceiver 130a, 130b includes an antenna 212a, 212b, analog transmission electronics 214a, 214b, digital transmission electronics 216a, 216b, and a clock interface 402a, 402b. The first transceiver 130a may also include a global property sensor 228, which may be operably coupled to the digital transmission electronics 216a.

[0148] For many applications, a transceiver will have fewer constraints (e.g., weight constraints, size constraints, power constraints) than a self-positioning device because the transceiver does not have to be mobile. Therefore, it may be preferable to shift complexity from the self-positioning device to the transceiver. Figure 4 The embodiment shown has several technical advantages. First, Figure 4 The transceiver pair shown in can be implemented as redundant receivers to provide additional protection against failures. Depending on the use case, redundancy can be implemented for some or all of the components of the transceiver. Second, the transceivers 130a, 130b can be configured to use different antennas 212a, 212b as shown to provide additional functionality. For example, the antennas 212a, 212b can differ in factors such as their orientation, their antenna polarization, or their gain. This can provide technical advantages to the receiver, including improved signal-to-noise ratio or less variation in signal reception across different receiver antenna orientations. In some embodiments, Figure 1-Figure 3 The transceiver 130 may use multiple antennas 212, for example, in connection with an RF switch.

[0149] When paired with similar self-locating devices (e.g. Figure 7When used with Figure 4 The use of a pair of transceivers as shown may have additional advantages. In some embodiments, transceivers 130a and 130b may use different positioning signals. For example, transceiver 130a may use a first frequency band, while transceiver 130b may use a second, different frequency band. Using two different positioning signals simultaneously may allow for higher update rates. It may also provide improved interference immunity. It may also allow for the elimination of signal-dependent effects based on true distance differences. For example, because the speed of a signal depends on the refractive index of an obstacle and the wavelength of the signal, using two different signals with two different wavelengths may allow for the inference of delays introduced by obstacles.

[0150] Paired embodiments can also be used to detect faults. This can be achieved, for example, by receiving a first signal from a first transceiver; receiving a second signal from a second transceiver physically attached to the first transceiver; comparing data related to the first signal with data related to the second signal while taking into account differences between the two signals; and comparing the result to a threshold. Examples of compared data include: signal reception; signal arrival accuracy; and signal peak power. Examples of differences between the two signals include: relative antenna position; time delay between transmissions of the first and second signals; and signal preambles.

[0151] In some embodiments, a fault detection unit (not shown) is used to detect the fault. In some embodiments, the fault detection unit is on the self-locating device. In some embodiments, the fault detection unit is not on the self-locating device. In some embodiments, a single fault detection unit is used. In some embodiments, paired antennas can be used to implement a multi-antenna configuration.

[0152] Figure 4 The illustrated transceiver also includes digital receive electronics 222a, 222b and analog receive electronics 220a, 220b. This allows each of the transceivers 130a, 130b to wirelessly exchange signals 302. In some embodiments, the transceivers 130a, 130b do not include some or all of the electronics 222a, 222b, 220a, 220b.

[0153] In some embodiments, the transceiver of the present disclosure can be used with a multi-antenna arrangement. A multi-antenna arrangement includes at least two resonant elements (sometimes referred to as "antennas") with known diversity (e.g., spatial diversity, temporal diversity, polarization diversity, pattern diversity, etc.).

[0154] The resonating elements of a multi-antenna arrangement may differ in one or more characteristics (e.g., polarization, frequency response, sensitivity, orientation, etc.). For example, the antennas may be spaced a known distance apart. As another example, the antennas may be oriented orthogonally relative to each other. The resonating elements of a multi-antenna arrangement may be used and combined in various ways using well-known RF techniques (e.g., duplexers, power splitters, etc.). The multi-antenna arrangement may include specialized electronics for individual resonating elements.

[0155] In some embodiments, antennas 212a, 212b of a transceiver may be used to implement a multi-antenna arrangement. The multi-antenna arrangement may include separate electronics 214a, 214b, 216a, 216b, 220a, 220b, 222a, or 222b for separate resonant elements. For example, the multi-antenna arrangement may include separate receive electronics for the antennas.

[0156] In some embodiments, the transceiver is equipped with multiple antennas. In some embodiments, the multiple antennas of the transceiver are used to implement a multi-antenna configuration. In some embodiments, the self-positioning device is equipped with multiple antennas. In some embodiments, the multiple antennas of the self-positioning device are used to implement a multi-antenna configuration. In some embodiments, the transceiver and the self-positioning device each have a multi-antenna configuration.

[0157] In some embodiments, the same antenna is used for both transmission and reception. In some embodiments, different antennas are used for transmission and reception. For example, a transmitter may use a directional antenna while a self-positioning device uses an omnidirectional antenna, or vice versa. Various types of antennas may be used and combined to achieve the desired behavior for a given use case. For example, antennas using multiple resonant elements, multi-beam adaptive antennas, or multiple-input, multiple-output (MIMO) antennas may be used. In some embodiments, antennas supporting multiple frequency bands may be used. In some embodiments, the antennas of a multi-antenna device may be isolated from one another.

[0158] In some embodiments, a multi-antenna configuration can improve the positioning performance of a positioning unit or position calibration unit. In some embodiments, this can be achieved by improving reception (e.g., signal-to-noise ratio, etc.). In some embodiments, the antennas and receiving electronics are configured to detect signal strength. In some embodiments, signal strength is used to provide a relative indication of distance to a transmitter.

[0159] In some embodiments, a directional antenna is used. In some embodiments, the antenna is configured to detect the direction of the signal, which can indicate the direction of the signal source. In some embodiments, the antenna and receiving electronics are configured to allow detection of the amplitude or phase of the signal. In some embodiments, knowledge of the amplitude or phase of the transmitted signal and the detected amplitude or phase of the signal are used to provide a relative indication of the direction or distance relative to the transmitter.

[0160] In some embodiments, a multi-antenna setup can allow the attitude of a self-positioning device to be determined. For example, in some embodiments, a multi-antenna setup can be used to detect the polarization of a signal. Knowledge of the transmitted polarization of the signal, along with the detected polarization of the signal, can provide a relative indication of the orientation of a transmitter (e.g., a transceiver) and a receiver (e.g., another transceiver or a self-positioning device).

[0161] In some embodiments, the antennas of a multi-antenna arrangement can operate at different frequencies. For example, the multi-antenna arrangement can be used in a redundant transceiver network operating at two different frequencies. As another example, the multi-antenna arrangement can be used in a self-locating device used in a redundant transceiver network operating at two different frequencies.

[0162] In some embodiments, the antenna, analog receive electronics, and digital receive electronics are configured to measure the Doppler shift of the signal. This can allow the positioning unit to improve its position estimate, for example, by providing data related to the movement of the self-positioning device relative to the known position of the transceiver.

[0163] In some embodiments, the advantages of a multi-antenna arrangement of a transceiver and a multi-antenna arrangement of a self-positioning device can be combined. For example, this can be achieved by combining knowledge of the properties of the multi-antenna arrangement of the transceiver (e.g., the location of the transceiver), knowledge of the properties of the transmitted signal (e.g., signal strength, signal polarization), and knowledge of the properties of the multi-antenna arrangement of the self-positioning device (e.g., the relative alignment of the resonant elements of its antenna array and its reception characteristics).

[0164] In some embodiments, the positioning unit is used to fuse data from one or more of: a multi-antenna setup; a sensor; a global property sensor; a first and a second global property sensor; and a known position.

[0165] A multi-antenna configuration may have technical advantages. In some embodiments, a multi-antenna configuration may allow for optimized reception, improved signal-to-noise ratio, or increased data rates. This may be achieved, for example, by allowing for better reception across a range of receiver positions or orientations. As another example, a multi-antenna configuration may be used to implement spatial multiplexing in a MIMO system to increase data rates.

[0166] In some embodiments, the effects of system components on the positioning signal are known. For example, the RF components of a transceiver may have well-known transmission properties. As a further example, the electronic components and structural components of the self-locating device may have well-known RF responses. In some embodiments, known RF effects are compensated for by a compensation unit. In some embodiments, the antenna may utilize shielding.

[0167] It should be understood that although in different embodiments Figure 2-Figure 4 The transceiver 130 is described as having both wireless transmission and wireless reception capabilities; however, the wireless reception capability is optional. For example, in some embodiments, the transceiver 130 does not include a wireless reception component. In some embodiments, the transceiver 130 is configured to exchange synchronization information and other information with other transceivers 130, the scheduling unit controller 120, or the scheduler 110 using a wired connection. As described above, a transceiver is also referred to as an anchor. Therefore, it will also be understood that an anchor, as used herein, may include both a wireless transmission component and a wireless reception component, or may include only a wireless transmission component.

[0168] Figure 5 is a block diagram of an illustrative self-positioning device 140 according to some embodiments of the present disclosure. Self-positioning device 140 includes an antenna 502 for receiving positioning signal 202. Antenna 502 is operably coupled to analog receiving electronics 504, which can amplify the signal. Digital receiving electronics 506 can then be used to time-stamp the signal with reference to clock 508. Synchronization unit 510 can compare input from clock 508 with input from other clocks (e.g., received as part of a synchronization signal or message from another part of the positioning system and received by digital receiving electronics 506). Synchronization unit 510 can use this information to calculate a clock correction for clock offset or clock rate, which it can transmit to positioning unit 512 or compensation unit 516 or store in memory 518. Additionally, information from compensation unit 516 can be used.

[0169] Figure 5 The self-positioning device 140 can be used, for example, with Figure 2 In this embodiment, Figure 5 The self-positioning device 140 receives the signal generated by the self-positioning device 140 through its antenna 502, analog receiving electronic device 504 and digital receiving electronic device 506. Figure 2 The self-positioning device 140 may use the time-stamped positioning signal 202 transmitted by the transceiver 130. The self-positioning device 140 may use the signal 202 to calculate its position relative to the transceiver 130. In some embodiments, this is accomplished by time-stamping the signal 202, converting the time-stamps into distances, and using these distances to calculate the relative position. This conversion may use an estimate of the speed of the signal 202 in the transmission medium (e.g., the speed of light in air). This conversion may be performed using the positioning unit 512. The positioning unit 512 may calculate the position of the self-positioning device relative to the known position of the transceiver 130 using trilateration or multilateration. The digital receiving electronics 506 and the clock 508 may provide sufficiently accurate time-stamps.

[0170] The receiving electronics 504, 506 can accurately determine the time at which the transmitted signal arrives at the antenna 502. Determining the time of reception of the signal ("time stamping") can be performed by determining the time at which the symbol is detected. For transmissions compliant with the IEEE 802.15.4 standard, a common choice for time stamping a symbol is the beginning of the start-of-frame delimiter (i.e., the point at which the transmitted signal changes from repeated transmissions of the preamble to transmissions of the start-of-frame delimiter). The digital receiving electronics 506 use a signal provided by the device's clock 508 as a reference for this time stamping process. The time stamp can therefore be expressed relative to this clock. In some embodiments, the clock 508 comprises an onboard clock. The receiving electronics 504, 506 can also provide additional metrics related to the received signal 202.

[0171] For example, quality metrics may include signal strength, reception time standard deviation, or noise properties of the signal. Quality metrics may be calculated based on absolute values ​​(e.g., absolute signal strength) or relative values ​​(e.g., differences in signal strength). Quality metrics may also be calculated by comparing signals. For example, quality metrics may be based on comparing signals with respect to time, comparing signals from different transceivers, comparing signals received from different directions, comparing a signal to a threshold, comparing a signal to its expected properties, and so on. Comparisons may use individual signal properties (e.g., peak power) or the entire signal (e.g., the spectral shape of the signal). For example, quality metrics may be used to determine whether signal 202 travels within line of sight, what materials it may have passed through, or how it may have been reflected.

[0172] Figure 5 (and Figure 2 ) may further include a global property sensor 520. Global properties may allow the relative position of the self-positioning device 140 to be calculated more accurately by providing additional reference data about a reference point (e.g., a transceiver or a coordinate system). This may be achieved by equipping at least one of the transceiver 130 and the self-positioning device 140 to detect global properties. The accuracy of the positioning system may be improved by a method comprising the steps of: (i) transmitting global property readings of a transceiver to the device; (ii) comparing readings of the global properties of the transceiver at its location with readings of the global properties of the device at its location; (iii) converting the comparison into data relating to orientation, position, or movement using a model of the global property ("global property model"), and (iv) appropriately fusing the data with other sensor data by using an estimator. Steps (ii) and (iii) may be performed using a positioning unit 512 (such as that shown as Figure 5This is accomplished by the positioning unit 512 that is part of the self-positioning device 140. The global property model allows one or more readings of global properties to be converted into data that can be processed by the positioning system (e.g., an equation describing atmospheric pressure as a function of altitude / height). The model can take various forms, such as a function or a lookup table.

[0173] In addition to other data provided by the positioning system (e.g. from local, onboard sensors (e.g. Figure 5 In addition to data from onboard sensors 514), data from one or more global attribute sensors (e.g., Figure 3 Global property sensors 228 (e.g., sensors with global properties) can be particularly useful in the presence of systematic sensor errors or sensors with high noise rates. For example, in an exemplary embodiment for an outdoor installation, in addition to positioning signal 202, the device and multiple transceivers can be equipped to receive GPS signals. This can allow the self-positioning device 140 to use positioning unit 512 to determine its position not only relative to transceiver 130 but also relative to a global reference frame. Furthermore, this combination of positioning modalities can allow for the detection of erroneous data by comparing readings from two independent measurement systems. The positioning system can be further improved by equipping the transceiver and device with additional sensors (e.g., barometers) to detect global properties. This can be particularly useful for enabling positioning unit 512 to achieve more accurate, reliable, or faster positioning in the vertical direction, where both GPS and local positioning systems can provide poor information due to the unfavorable positioning of transceivers (typically all located on the ground, below the device) and GPS satellites (high in the sky, typically above the device).

[0174] The global signal can also be used to determine the relative orientation of the communication transceiver's antenna 212 and the self-positioning device's antenna 502, which can have a significant impact on the signal quality or group delay and, therefore, their calculated relative positions. The orientation can be determined, for example, by detecting the transceiver's gravity vector (e.g., using an accelerometer), transmitting this information to the device (e.g., as part of the payload of the positioning signal), and comparing it with the gravity vector detected by the device (possibly corrected for the effects of the device's motion) using a model of each of the transceiver's antenna orientation and the device's antenna orientation relative to its accelerometer. This comparison can be performed by a compensation unit (e.g., Figure 5 The compensation unit 516 is executed.

[0175] As described above, the positioning unit 512 uses data to calculate a position estimate. The data may include received signals 202, data from one or more onboard sensors 514, data from one or more off-board sensors (e.g., the transceiver's global property sensor 228), or other data. Data related to the received signals 202 may include payload, time stamp, signal characteristics (e.g., signal strength, peak shape, etc.), etc. This may be achieved by using an estimator to calculate an estimate of the position (and possibly orientation or motion) of the self-positioning device 140 based on a fusion of the current value of the data and other information (e.g., knowledge of the input history, a dynamic model of the device). Each individual received signal 202 may be recursively used to provide an updated (a posteriori) position estimate by combining it with a previous (a priori) estimate. In some embodiments, the estimate may be recursively calculated using an (extended) Kalman filter, a complementary filter, a particle filter, a Luenberger observer, or any other suitable technique. Positioning unit 512 may collect a number of positioning signal receptions (e.g., 3, 4, 5, 6, 7, 8, 9, 10, etc.) by storing the number of positioning signal receptions in a memory (e.g., memory 518) and batching them (after a predetermined number of signals are received, or at fixed time intervals). The batching method may be based on multilateration techniques by solving a time difference of arrival (TDOA) metric for the position of device 140. In some embodiments, a combination of recursive and batching may be used.

[0176] The memory 518 can be used to store information (such as data from the received signals 202 for batch processing of current position estimates) or parameters for recursive calculations and sensor fusion. The positioning unit 512 can also use data from the compensation unit (e.g., compensation values) or information about the received signals 202 generated by the digital receiving electronics 506 (e.g., quality metrics).

[0177] Variations in signal quality or group delay may be due to the fact that the transceivers and the self-positioning device are small and may be operated relatively close to each other. This may result in a variety of relative orientations, relative distances, and relative directions of the transmitter antenna 212 relative to the receiver antenna 502 used in typical applications and encountered during typical use, such as multiple transceivers located on a plane with the device operating above or below the plane, or multiple transceivers located around a volume with the device operating within the convex hull of the volume.

[0178] Unlike in other positioning systems, the signals 202 arriving at the self-positioning device may have different qualities or different group delays. In some embodiments, the positioning unit 512 may be configured to improve position estimates on existing positioning systems by using characteristics of the positioning signal and quality metrics related to the received positioning signal, such as quality metrics provided by the receiving component (e.g., UWB peak signal strength, UWB peak shape). This may be achieved, for example, by correlating measurement variance with the signal metric, such that measurements with higher variance have less impact on the positioning unit's state estimate. As another example, the positioning unit may place greater emphasis on data not related to the positioning signal (e.g., inertial sensors, global attributes). As another example, the positioning unit may completely discard measurements from certain transceivers that do not meet a quality metric (e.g., minimum signal quality or group delay).

[0179] Unlike existing systems, here, the positioning unit 512 can be located on the self-positioning device 140 because the time-stamped positioning signal traveling from the transceiver to the self-positioning device can contain enough information to allow the device to self-position. For example, the transceivers can be synchronized and their positions are known to the device.

[0180] Figure 6 is an illustrative timing diagram depicting the propagation of a received positioning signal (e.g., a UWB signal) through the antenna 502, analog receive electronics 504, and digital receive electronics 506 of a self-positioning device according to some embodiments of the present disclosure. The interconnection of these components will be referred to as a receive pipeline. Each of these components introduces a delay to the propagation of the received signal. Time is shown on the vertical axis, with the symbol A t is used to indicate that the time t is measured with reference to the clock of the positioning device A.

[0181] Consider the time A t0 Rx The signal arriving at the antenna 502 of the self-positioning device at 602 propagates through the receiving pipe and thereafter arrives at time A t0606 is time stamped by the digital receiving electronics 506. The delay introduced by the pipeline (due to A t0 606 and A t0 Rx 602) is expressed as A δ0 604 and is called pipeline delay. Now consider the second signal, the second signal at time A t1 Rx 612 arrives at the antenna 502 of the self-positioning device and is delayed by the pipeline through the receiving pipeline. A After δ1614, at time Ais time-stamped at t1 616. The change in pipeline delay between these two signals is given as | A δ1- A δ0|. Note that this measurement is with respect to the clock of the self-positioning device 140 and is therefore independent of clock rate offsets. In some embodiments, the difference between pipeline delays 604 and 614 is less than 0.01, 0.6, 3, or 15 nanoseconds, which allows for more accurate positioning.

[0182] Variations in pipeline delay are affected by physically measurable factors, including the frequency response of the self-locating device antenna 502, its internal amplification, and the accuracy and variation of the time stamps generated by the digital receive electronics 506. Because antennas are non-ideal electromagnetic devices, their frequency response is described by a reception angle-dependent amplitude response, corresponding to how much the radio signal is amplified or attenuated by the antenna, and a reception angle-dependent phase response, corresponding to how much the radio signal is delayed by the antenna. These responses are deterministic functions of the angle at which the signal is received and result in an electrical delay of the signal as it passes through the antenna 502. In some embodiments, signal propagation through the analog receive electronics 504 and the digital receive electronics 506 can be further delayed by the signal's internal amplification (to achieve consistent signal levels regardless of received signal strength). Furthermore, the ability of the digital receive electronics 506 to consistently and accurately time-stamp the arrival of UWB signals requires that it consistently and accurately identify the signal's "first path." Errors in this identification, discussed below, lead to non-constant errors in the time-stamping process and, consequently, to perceived delays in the signal's propagation time through the receive pipeline. In addition to systematic pipeline delays, in some embodiments, random, external, or unmodeled processes may also affect pipeline delays, thereby introducing non-systematic delays in the receive pipeline. In some embodiments, temperature is an example of such a process, whereby changes in temperature can affect the processing time required by the digital receive electronics 506.

[0183] The effect of non-constant pipeline delay is to introduce non-constant errors in the reception time of any signal 202. Therefore, it will be apparent to those skilled in the art that Figure 6 The non-constant pipeline delay shown may correspond to a non-constant error in any time of arrival or time of arrival distance measurement derived from the reception time of any signal 202. In some embodiments, the compensation unit (e.g., Figure 5 The compensation unit 516 can compensate for this systematic but non-constant error.

[0184] Figure 7FIG2 is a block diagram of an illustrative self-positioning device including a pair of first and second self-positioning devices 140a, 140b, according to some embodiments of the present disclosure. The self-positioning devices 140a, 140b are physically coupled together using a structural element 700. Each self-positioning device 140a, 140b includes an antenna 502a, 502b, analog receiving electronics 504a, 504b, digital receiving electronics 506a, 506b, and a positioning unit 512a, 512b. As shown, the pair of positioning units 512a, 512b are operatively coupled using a communication path 702. The communication path 702 allows the positioning units 512a, 512b to exchange data related to their locations (e.g., their current location estimates).

[0185] Structural element 700 provides a rigid or semi-rigid attachment between self-positioning devices 140a and 140b. In some embodiments, structural element 700 may comprise one or more of the following: a printed circuit board (PCB) holder, a multi-purpose packaging box, a support or connecting rod, and the like. Because self-positioning devices 140A and 140B are physically connected, their relative positions are fully or partially known. This allows first positioning unit 512a to refine its position estimate based on data related to second positioning unit 512b and the known relative positions of first and second positioning units 512a and 512b.

[0186] In some embodiments, Figure 7 The pair of self-positioning devices 140a, 140b shown in FIG can operate as redundant self-positioning devices, which can provide protection against failures. For example, if a component in the first self-positioning device 140a fails, the positioning system can rely on the second self-positioning device 140b. Depending on the use case, redundancy can be implemented for some or all of the components of the self-positioning devices.

[0187] As shown, the first and second self-positioning devices 130a and 130b use different antennas 502a and 502b. In some embodiments, the antennas 502a and 502b can have different characteristics. For example, the antennas 502a and 502b can differ in factors such as their orientation, their antenna polarization, or their gain. This can produce technical advantages, including improved signal-to-noise ratio or less variation in signal reception when the self-positioning device moves.

[0188] In some embodiments, a multi-antenna arrangement can be implemented using the antennas 502a, 502b of the self-positioning device. The multi-antenna arrangement can include some separate electronic devices 504a, 504b, 506a, 506b for a single resonant element. For example, the multi-antenna arrangement can include separate receiving electronics for the antennas.

[0189] In some embodiments, the self-positioning devices 140a, 140b further include corresponding sensors 514a, 514b. Each sensor 514a, 514b is operably coupled to a corresponding positioning unit 512a, 512b. The sensors 514a, 514b can allow the corresponding self-positioning device to improve its positioning. In some embodiments, the first positioning unit 512a can transmit data related to its position (e.g., its current position estimate, its sensor 514a readings) to the second positioning unit 512b. This can allow the second positioning unit 512b to improve its position estimate.

[0190] It will be understood that one can use Figure 7 The self-positioning device is replaced by Figure 2 and Figure 5 Single self-locating device shown.

[0191] Figure 8 is a block diagram of an illustrative self-positioning device 140 including a plurality of selectable antennas 502a, 502b, 502c according to some embodiments of the present disclosure. The self-positioning device 140 also includes a radio frequency switch (RF switch) 800 for selecting a particular one of the antennas 502a, 502b, 502c for use. In some embodiments, the RF switch 800 includes a single-pole double-throw (SPDT) switch or a multi-port (SPnT) switch. The parameters of the RF switch 800 (e.g., frequency range, isolation, switching speed, etc.) can be optimized to suit a particular use case. Figure 8 As shown in , the RF switch 800 is used as a multi-antenna configuration. In some embodiments, the antennas 502a, 502b, and 503c can have different characteristics. For example, the antennas 502a, 502b, and 503c can differ in one or more of the following characteristics: orientation, polarization, gain, and antenna type. The positioning unit 512 or other components of the self-positioning device 140 can control the RF switch 800 to select one of the multiple antennas based on positioning information. The positioning information may include, for example, one or more of the following: the position of the self-positioning device, the orientation of the self-positioning device, the next positioning signal to be received, the quality associated with one or more antennas, the antenna type, and any other positioning information. It will be understood that in some embodiments, the RF switch 800 and the multiple selectable antennas 502a, 502b, and 502c can be used with any other self-positioning device disclosed herein.

[0192] Figure 9 is a block diagram of an illustrative positioning unit 512 including a location update process according to some embodiments of the present disclosure. Figure 9The localization algorithm depicted in FIG. 1 takes the form of an extended Kalman filter (EKF). The localization unit 512 can be used with any suitable self-localization device 140 disclosed herein. At the beginning of a cycle, the localization unit 512 performs a process update step 920, in which it uses the device's previously estimated state and, if available, data from the control unit 940 indicating signals to be sent to one or more actuators. The result of this step is a prior estimate 922 (e.g., an estimate of the current state of the device 140 without considering any recently taken measurements). This prior estimate is then fused with the available measurements. The prior estimates, measurements, and other data used by the localization unit 512 may be temporarily stored in memory (not shown).

[0193] The first type of measurement is the reception of the positioning signal 202. In this case, the time stamp 900 of the received signal is first processed by clock correction 902 (using data from the synchronization unit 510) and effect compensation 904 (using data from the compensation unit 516). The resulting corrected arrival time 906 represents an estimate of when the positioning signal arrives from the positioning device antenna 212, which can then be fused with the a priori estimate in the EKF measurement update step.

[0194] As described above, the resulting corrected time of arrival 906 represents an estimate of the time at which the positioning signal 202 arrives at the device's antenna 212. In some embodiments, transmission information is included in the payload of the received positioning signal, indicating when the signal was transmitted and by which transceiver 130. This transmission information, along with the corrected time of arrival, is a measure of the distance between the device 140 and the transceiver 130. In the positioning unit 512, the corrected time of arrival and the transmission information can be fused with the a priori estimate in an EKF measurement update step 924.

[0195] If new data is available, the second type of measurement is data representing a local measurement of a global property (e.g., from the global property sensor 520). This data is then compared at comparison 912 with one or more remotely measured data representing the global property (e.g., from the global property sensor 228) (provided by the digital receiving electronics 506), and the global property model 914 provides information about how the comparison relates to the position, orientation, or motion of the self-positioning device 140. This information can then be fused into the state estimate at the EKF measurement update step 924. An example of a global property is the signal strength of a wireless signal. The free space path loss of a radio frequency signal of frequency f transmitted over a distance d is:

[0196] FSPL(dB)=20log10(d)+20log10(F)+K,

[0197] where K is a constant that depends on the units used for d and f. By this equation, the distance from the positioning device to the wireless signal source can be related to the distance from the transceiver(s) 130 to the same source.

[0198] If new data is available, the third category of measurements comes from sensors such as sensor 514. Such measurements may also be fused into the state estimate in the EKF measurement update step 924.

[0199] The estimate of the local clock behavior by the synchronization unit 510 and the estimate of the compensation value by the compensation unit 516 may depend on the estimated position calculated by the positioning unit 512. This dependency may be resolved by first calculating the clock behavior and compensation value using the a priori position estimate and then calculating a new a posteriori position estimate 926. The dependency may also be resolved by estimating the clock behavior or clock correction, compensation value, and position in parallel, or iteratively by alternating between: 1) calculation of the new clock behavior or clock correction and compensation value using the current position estimate, and 2) position estimation using the current clock and compensation value until the calculated values ​​have substantially converged.

[0200] In some embodiments, Figure 9 The positioning unit 512 and other components depicted in FIG can be integrated with the mobile robot. In such a configuration, the control unit 940 can be configured to calculate actuator commands based on the position calculated by the positioning unit 512 to control the mobile robot.

[0201] Figure 10 An illustrative mobile robot 1000 is shown that includes a self-positioning device 140 in accordance with some embodiments of the present disclosure. The mobile robot 1000 may also include one or more sensors (e.g., a MEMS sensor and sensor 514). In some embodiments, the mobile robot 1000 includes an accelerometer 1006 and a gyroscope 1008. In some embodiments, the mobile robot 1000 additionally includes one or more of a magnetometer, a barometer, a GPS receiver, and proprioceptive sensors (e.g., sensors that monitor battery level and motor current). The illustrated mobile robot 1000 also includes actuators 1004 (e.g., four motors) for rotating four propellers 1010 that allow the mobile robot to remain airborne and control its movement through space. In some embodiments, the actuators 1004 are powered by batteries. In some embodiments, the transceiver or device is powered by batteries.

[0202] Figure 10The self-positioning device 140 can be integrated with the electronics of the mobile robot 1000 (e.g., the central processing electronics 1002). For example, the device 140 can access the sensors of the mobile robot 1000 (e.g., the sensor 514, the accelerometer 1006, and the gyroscope 1008). For example, this can be useful or convenient for achieving a specific weight distribution on the flying robot, allowing for better antenna reception, or for co-locating related electronic components.

[0203] Depending on the application, the flight electronics may be more complex than the embodiments described here and may, for example, include multiple electronic processing units, multiple antennas or multiple self-positioning devices.

[0204] Figure 11 According to some embodiments of the present disclosure, Figure 10 1000. The control unit 940 uses a cascade of controllers (horizontal controller 1102, vertical controller 1110, lowering attitude controller 1120, yaw controller 1130, and body velocity controller 1142, with reference signal / feedback signal flows omitted for clarity).

[0205] The control scheme depicted in the control unit 940 is used to follow the desired vehicle position and yaw trajectory. The onboard control includes four separate loops: horizontal position control 1102 and vertical position control 1110 loops, lowering attitude control 1120 loop, and yaw control 1130 loop. It should be understood that the control scheme used to Figure 11 The reference numerals of the controllers within the control unit 940 are also used to refer to the control loops associated with the controllers. The outputs of the four control loops are Figure 10 The three body velocity commands of the flying mobile robot 1000 are shown, along with the collective thrust generated by the mobile robot's four propellers 1010.

[0206] Figure 11The control strategy shown is based on a cascaded loop shaping design strategy. Therefore, the controller design is broken down into the design of several lower-order dynamic system controllers. The vertical control loop 1110 is shaped so that it responds to altitude errors like a second-order system using a collective thrust c 1112. Similar to the vertical control loop 1110, the two horizontal control loops 1102 are shaped to behave like second-order systems. However, instead of directly calculating the control inputs, the commanded accelerations a(x) 1104 and a(y) 1106 are given as setpoints to the attitude controller 1120. The attitude controller 1120 controls the mobile robot's attitude descent such that the commanded accelerations a(x) 1104 and a(y) 1106 are satisfied. The commanded accelerations are then converted into commanded rotation matrix entries. Using the mobile robot's rotational kinematics, the rates of change of the matrix entries can be used to calculate the desired body velocities p 1122 and q 1124. The above controller fully defines the mobile robot's translational behavior. The yaw controller 1130 can then be implemented as a proportional controller to calculate a desired yaw rate r based on the measured yaw angle (e.g., as measured by sensor 514 on the mobile robot 1000). The body rate controller 1142 receives the (measured or estimated) current body rate, the desired vehicle body rate p 1122, q 1124, and i 1132, along with the collective thrust c 1112. The control unit 940 outputs actuator commands f1, f2, f3, f4 1144 to the actuators 1004 to cause movement 1146 of the mobile robot 1000.

[0207] Figure 12 An illustrative transceiver network including a plurality of transceivers 130 is shown according to some embodiments of the present disclosure. Such a transceiver network can allow the use of self-positioning devices 140 in a wide geographical area by allowing a large number of transceivers to be used simultaneously. Figure 12 As shown, if the transmission ranges 1400 of two transceivers overlap, the transceivers are said to be "interfering" because simultaneous transmission of positioning signals 202 by the two transceivers may cause the positioning signals 202 to interfere with each other. The transmission range can be defined, for example, as the boundary of the area where the signal strength of the transmitted signal drops below the receiver sensitivity. To avoid signal interference, the signal transmissions of transceivers in a particular area are typically coordinated. In some embodiments, this can be achieved by ensuring that the signals are sufficiently separated in time (e.g., by sufficient time between two signal transmissions, e.g., using a scheduling unit), space (e.g., by sufficient geographical separation of the transceivers), or frequency (e.g., by sufficient separation of the transmission carrier frequencies of the UWB signals).

[0208] The amount of time required for sufficient temporal signal spacing may depend on many factors (e.g., signal strength, signal packet size, signal pulse / peak shape, transceiver antenna, receiver antenna, geographic location of the transceivers (including their geographic spacing), obstructions, background noise, etc.). Ensuring the temporal spacing of signals may mean that the duration between subsequent signals from any particular transceiver increases as the number of transceivers grows. This can be particularly problematic for dynamic autonomous mobile robots, where even relatively small reductions in update rates can result in significant positioning performance degradation. A known method for ensuring temporal spacing is time division multiple access (TDMA). In embodiments where occasional signal interference is acceptable and where signal timing is unimportant, the Aloha method may also be used.

[0209] Sufficient separation in space relative to the transmission range of each transceiver may depend on many factors (e.g., signal strength, signal frequency, signal bandwidth, signal pulse / peak shape, transceiver antenna, receiver antenna, geographic location of the transceivers (including their geographic separation), obstructions, background noise, etc.). In some embodiments, a typical spatial separation is 1-100 meters. In some embodiments, a typical spatial separation is 10-500 meters. In some embodiments, a typical spatial separation is 200-2000 meters. In some embodiments, a typical spatial separation is on the order of kilometers. In some embodiments, two transceivers may be co-located. In some embodiments, a combination of multiple spatial separations is used. Figure 12 , for simplicity, the transmission range 1200 is graphically represented as a circle; however, it will be apparent to those skilled in the art that the transmission range 1200 can be a more complex shape. When ensuring spatial separation of transmissions, it may be desirable to place the transceivers 130 so that the self-positioning device 140 will be able to receive transmissions from a predetermined number of transceivers 130 at each point within a defined geographic area. This number of transceivers 130 may depend on many factors (e.g., desired update rate, desired system robustness, time interval between transmissions, frequency spacing of transmissions, background noise, obstructions, etc.).

[0210] Achieving adequate spatial separation can be further assisted by selecting appropriate antennas. Some embodiments use directional antennas. Some embodiments use omnidirectional antennas. In some embodiments, directional antennas are used to help ensure the spatial separation of positioning signals. In some embodiments, by using directional antennas to direct the transmissions of the transceivers 130, it is possible to more accurately control which transceivers 130 transmit to which areas in a defined space, and thereby more accurately control the spatial separation of the positioning signals 202. In some embodiments, by using directional antennas to direct the transmissions of the transceivers 130, it is possible to achieve a longer transmission distance in the desired direction. Other methods that can assist in spatial separation include shielding, placement (e.g., away from noise sources), optimizing radiation patterns, and combinations of the above. In some embodiments, by equipping the self-positioning device 140 with directional antennas, orientation information can be estimated based on comparing which signals are received with the known positions of the transceivers 130.

[0211] In some embodiments, the transceivers 130 are arranged so that coverage of a desired operating area is optimized relative to a certain metric. In some embodiments, the operation of the transceivers 130 is optimized relative to a certain metric. Suitable metrics may include the number of transceivers in range, signal strength, update rate from a specific transceiver combination, multipath effects, or other metrics, including combined metrics. Transceiver placement may include transceiver location, transceiver antenna orientation, transceiver operating frequency, transceiver bandwidth, or other factors. The operating area may be a geographic area, the flight volume of the flying robot 1000, a predefined operating volume, or other area. Optimization may involve physical parameters (such as geographic placement of transceivers, antenna orientation, etc.) or operational parameters (such as the operation of the scheduling unit 218). In some embodiments, optimization may be performed by a scheduler. In some embodiments, optimization may be pre-calculated. In some embodiments, the schedule is manually created. In some embodiments, the schedule is created based on optimization. For example, in some embodiments, given the constraint that each point within a predefined area can receive signals from, for example, at least three transceivers, the optimal schedule can be determined by minimizing the number of transceivers per sector or region. For certain problems, such a schedule can ensure that the self-locating device can perform three-dimensional positioning over the entire defined area while further minimizing the TDOA cycle time within the cell (which can be proportional to the number of transceivers within the cell). As another example, in some embodiments, the schedule can be calculated as the solution to an optimization problem that trades off the cost of changing the frequency of the self-locating device against the cost of increasing the TDOA cycle time.

[0212] Adequate spacing in transmission frequencies can depend on many factors (e.g., signal strength, signal frequency, signal bandwidth, signal pulse / peak shape, transceiver antenna, receiver antenna, geographic location of the transceivers (including their geographic spacing), obstructions, background noise, etc.). In some embodiments, a scheduling unit can be used to implement this spacing. In some embodiments, the spacing is in the range of 1-50 MHz. In some embodiments, the spacing is in the range of 100-500 MHz. In some embodiments, the spacing is in the range of 200-1000 MHz. In some embodiments, overlapping transmission frequencies are used. When designing for signal frequency spacing, it may be important to consider that the self-positioning device 140 may need to change its receiving frequency to receive positioning signals 202 that are spaced apart in frequency. A known method for ensuring frequency spacing is frequency division multiple access (FDMA). In some embodiments, a combination of various frequency spacings is used.

[0213] In some embodiments, TDMA can be used to ensure the time interval of the positioning signals 202. In some embodiments, if the transceiver network includes N transceivers, N time slots will be allocated (one time slot for each transceiver 130), whereby a simple approach can be used. The time to cycle through all the time slots is sometimes referred to as the TDMA cycle time. In the case where all transceivers in the network are interfering, the allocation of N transceivers to N time slots is optimal because it is the minimum amount of time that allows each transceiver to transmit once per cycle. Other optimization criteria can be used, such as positioning performance or information propagation time. However, in the case of Figure 13 In the case where not all transceivers interfere as shown in , a different optimal TDMA allocation schedule is possible that uses fewer than N time slots and thus reduces the TDOA cycle time and increases the average rate at which the self-positioning device 140 will receive positioning signals 202.

[0214] Figure 13 Schematic simplified transceiver network according to some embodiments of the present disclosure is shown. Figure 13 In this case, transceivers 130a and 130b do not interfere. It will be clear to those skilled in the art that in this case, both transceivers 130a and 130b can utilize the same TDMA time slot because it is impossible for the self-positioning device to receive signals from both transceivers at the same time (due to the spatial separation of the two transceivers) and therefore the simultaneous transmissions will not interfere. Figure 13 In FIG, this is indicated by transceivers 130a and 130b having the same shading.

[0215] In some embodiments, the scheduling unit 218 can coordinate the scheduling of TDMA time slots. In some embodiments, synchronization of multiple transceivers 130 can be achieved via the synchronization unit 224 or by sharing a common clock 210 among the transceivers 130 to achieve a consistent schedule. In some embodiments, the time slot assignments (e.g., schedule) can be manually determined or programmed into a transceiver memory (e.g., memory 230). In some embodiments, the schedule can be calculated autonomously by the scheduler. In some embodiments, the schedule determined by the scheduler can be communicated via the scheduling unit controller.

[0216] In some embodiments, a scheduler (e.g., scheduler 110) may operate periodically or may be triggered by a transceiver 130 through the transmission of an appropriate signal 302. In some embodiments, signal 302 is transmitted in response to an event. In some embodiments, additional TDMA time slots are allocated for the transmission of any positioning signal 202 or transceiver signal 302. In some embodiments, the use of these TDMA time slots is coordinated by ALOHA. In some embodiments, transceivers 130 use these TDMA time slots to alert other transceivers 130 of the occurrence of an event. In some embodiments, these time slots are used by a scheduling unit controller to trigger a switch to a new schedule.

[0217] In some embodiments, periodic or triggered reallocation allows the network to adjust the schedule so that the allocation of TDMA time slots compensates for transceivers joining or leaving the transceiver network. In some embodiments, adding a transceiver 130 to the network can be accomplished by leaving one TDMA time slot unallocated to allow new transceivers 130 to announce their joining the network and triggering a reallocation of the transmission schedule (i.e., the allocation of TDMA time slots). In some embodiments, removing a transceiver 130 from the network can be accomplished by enabling a transceiver to monitor for non-transmissions by a transceiver 130 and triggering a redefinition of the transmission schedule if the transceiver 130 has not transmitted within a predetermined number of TDMA time slots for that transceiver 130.

[0218] In some embodiments, TDMA slot lengths of less than 0.1 ms, 0.5 ms, 1 ms, 2 ms, 2.5 ms, 5 ms, 10 ms, or 50 ms are used.

[0219] In some embodiments, the transceiver 130 may include an estimated position or timing information of the transceiver 130 within the payload of its positioning signal 202 or transceiver signal 302. In some embodiments, the transceiver 130 may be operable to receive these transmitted signals 202, 302. In some embodiments, the receiving transceiver may include a synchronization unit 224 for synchronizing a schedule of the receiving transceiver with a schedule of the transmitting transceiver based on the received timing or position information.

[0220] In some embodiments, in at least one schedule, transceivers 130 may be assigned more than one TDMA time slot, thereby allowing them to transmit more frequently within a TDMA cycle. In some embodiments, the allocation of multiple time slots may be determined, for example, based on Fisher information added by transceivers 130—a heuristic known to those skilled in the art that may be calculated based on the relative positions of the transceivers.

[0221] In some embodiments, frequency division multiple access (FDMA) is used to mitigate transceiver interference, whereby interfering transceivers can be assigned different transmission frequencies so that they no longer interfere. In some embodiments, interfering transceivers can be assigned different preambles or pulse repetition frequencies to achieve a similar effect.

[0222] Figure 14 An exemplary transceiver network according to some embodiments of the present disclosure is shown, in which transceivers 130 are grouped into adjacent cells 1410. In some embodiments, adjacent cells 1410 may employ FDMA technology to enable transceivers 130 from different cells 1410 to operate simultaneously without significant interference in areas 1420 where transmissions overlap. In some embodiments, different cells 1410 may use different transmission parameters for the transmission of positioning signals 202, such as different transmission center frequencies, frequency bandwidths, preambles, preamble modulation schemes, or pulse repetition frequencies, so that different cells 1410 can operate simultaneously without significant interference. This allows the self-positioning device 140 to receive the positioning signal 202 at any location in the network, even while moving through more than one cell during reception. Within each cell, TDMA may be used to coordinate the transmissions of the various transceivers 130.

[0223] Figure 1514. A mobile robot 1000 is shown operating within an area 1420 served by multiple transceiver cells 1410 at different frequencies, according to some embodiments of the present disclosure. The mobile robot 1000 includes two self-positioning devices 140 that are physically coupled to the mobile robot 1000. Because the mobile robot 1000 operates within an area served by multiple transceiver cells 1410, multiple positioning signals 202 at different frequencies can be present simultaneously in the area 1420. In some embodiments, this means that the two self-positioning devices 140 coupled to the mobile robot 1000, when considered together, receive positioning signals 202 at a higher rate than if all transceivers 130 were transmitting on the same frequency and using TDMA to coordinate their transmissions. In some embodiments, using two self-positioning devices 140 can allow one or more positioning units to update their position estimates at a higher rate. In some embodiments, the communication path (e.g., communication path 702) between the two self-positioning devices 140 can allow the positioning unit to calculate the heading and the location of the body to which the two self-positioning devices are attached (e.g., Figure 15 In some embodiments, having multiple self-positioning devices 140 may allow one or more positioning units to more accurately calculate the position.

[0224] As mentioned above, such as Figure 1 A scheduler 110 such as the scheduler 110 of the scheduler 110 can use one or more input parameters to determine a schedule for transmitting positioning signals by anchors of the positioning network. In some embodiments, the input to the scheduler 110 includes the location of the anchors and user requirements, such as desired positioning performance. Figure 16 Illustrative input parameter maps 1610 and 1620 are shown that may be used to determine a schedule according to some embodiments of the present disclosure.

[0225] Input parameter map 1610 illustrates two input parameters. The first input parameter is the location of the anchors 130. As shown, the positioning network includes six anchors 130. The locations of the anchors 130 can be automatically determined during a calibration step or can be determined by the user during system installation (e.g., based on a survey or available maps indicating installation locations). The second input parameter is the desired positioning performance of the positioning network. Input parameter map 1610 illustrates contour lines of desired positioning performance. As shown, a range from 1 to 0 is used to reflect desired positioning performance, with 1 reflecting high performance (e.g., performance is extremely important) and 0 reflecting low performance (e.g., no positioning performance is required). Intermediate values ​​between 1 and 0 indicate that some positioning performance is desired, but varying degrees of degradation are acceptable. In some embodiments, the contour lines of input parameter map 1610 reflect discrete levels of desired performance. For example, the desired positioning performance may be 0 below contour line 0, 0.5 between contour lines 0 and 0.5, 0.8 between contour lines 0.5 and 0.8, and 1 above contour line 1. In some embodiments, the contour lines reflect a continuous value between 0 and 1. Input parameter map 1620 is similar to input parameter map 1610, but input parameter map 1620 uses a binary map to reflect the desired positioning performance. The binary positioning performance includes two areas—an area where positioning is desired (1) and another area where positioning is not desired (0).

[0226] In some embodiments, the desired positioning performance in maps 1610 and 1620 is directly determined by the user (e.g., based on a building plan from which the area of ​​interest has been extracted), or it may be automatically generated (e.g., based on known motion patterns of the autonomous machine). It should be understood that maps 1610 and 1620 are merely illustrative, and the position of anchor 130 and the desired positioning performance may be input to the scheduler in any suitable form. For example, the position of anchor 130 may be input in a coordinate system using its coordinates. As another example, the desired positioning performance may be input using a function that defines positioning performance. As another example, the desired positioning performance may be input using an array of values ​​that define positioning performance within a coordinate system. As another example, the desired positioning performance may be input using the shape or position of a contour line.

[0227] In some embodiments, the input parameter map is a static map that is generated upon initialization of the positioning system and is not changed until a subsequent initialization or calibration of the positioning system. In some embodiments, the input parameter map changes over time and may therefore be dynamic. Figure 17An illustrative dynamic positioning performance map 1710 for determining a schedule according to some embodiments of the present disclosure is shown. The map 1710 includes a plurality of different frames that illustrate how positioning coverage requirements change over time. The shaded portion of each frame indicates an area where positioning coverage is required. The unshaded portion of each frame indicates an area where positioning coverage is not required. As shown, the positioning performance map 1710 is a binary map. Successive frames of the map 1710 illustrate snapshots of a binary performance map that is parameterized over time. Such a map may be stored as a dense sequence of snapshots, a sparse sequence of snapshots (using interpolation techniques between snapshots) using a parametric model (e.g., using a periodic function), using any other suitable model, or using any other suitable technique. It will be understood that the binary nature of the positioning performance map 1710 is merely illustrative, and that the map 1710 may also be implemented using continuous values ​​or using multiple discrete performance levels.

[0228] Figure 18 This diagram illustrates an illustrative example of how a schedule can be adjusted according to some embodiments of the present disclosure. In some embodiments, the schedule can be adjusted in real time based on positioning requirements. As shown in the upper left portion of panel 1810, a position map 1820a shows the positions of three mobile robots 1000 within a coordinate system. Each of the mobile robots 1000 may include one or more self-positioning devices 140 and be configured to transmit its position back to a positioning network. For example, the mobile robots 1000 may be configured to wirelessly transmit their position (e.g., via antennas 502 of the self-positioning devices 140) to one or more anchors of the positioning network. The mobile robots 1000 may also transmit additional information to the positioning network, such as their current speed or planned motion. Based on this information, a coverage requirement map 1830a may be extracted. In some embodiments, a scheduler, such as scheduler 110, may receive this information from the mobile robots 1000 and generate the coverage requirement map 1830a. In some embodiments, the coverage requirement map 1830a may be generated by requiring coverage within a fixed radius around the current position of each mobile robot 1000 and a fixed radius around the mobile robot's planned motion path.

[0229] The coverage requirement map 1830a can be used by the scheduler to calculate an appropriate schedule 1840a for a given requirement. Based on the trade-off between positioning performance and computational complexity, the scheduler can select the most appropriate schedule from a series of pre-calculated and stored schedules, or the scheduler can calculate a new, optimized schedule based on the requirement map 1830a. Information about the schedule 1840a can be transmitted to one or more control units of the positioning network for controlling the transmission of positioning signals from the network's anchors.

[0230] In some embodiments, the scheduler transmits information about schedule 1840a to the scheduling unit controller, which in turn transmits a signal to the anchor, causing the anchor to transmit according to the schedule. If schedule 1840a is a pre-calculated schedule, the scheduling unit controller may simply send a signal indicating which schedule to use (e.g., "Use schedule nr. 3"). If schedule 1840a is a newly calculated schedule, the scheduling unit controller may transmit the new schedule to the anchor and then, upon receiving it, signal the change of schedule.

[0231] The described process is then repeated to adjust the schedule in real time. As shown at the bottom of panel 1810, the position of mobile robot 1000 has changed in position map 1820b. The new position depicted in position map 1820b can be used to generate a new coverage requirement map 1830b, which in turn can be used to determine schedule 1840b. Schedule 1840b can then be used to control the transmission of positioning signals from the network's anchors as described above.

[0232] Figure 19 Another illustrative example of how a schedule may be adjusted according to some embodiments of the present disclosure is shown. In this example, a group of mobile robots 1000 moves in a relatively large space according to a predefined set of trajectories, and a set of anchors is distributed throughout the space. Position maps 1910a, 1910b, 1910c, and 1910d illustrate the positions of the mobile robots 1000 as they move along the predefined set of trajectories. Specifically, the group of mobile robots starts in the lower right quadrant and then moves counterclockwise through the four quadrants. To improve the positioning performance of the positioning network, it may be desirable to use only a subset of anchors close to the group of mobile robots 1000 and configure the other anchors not to transmit. In position map 1810a, since the mobile robot 1000 is located in the lower right quadrant, it may be desirable not to use the anchors in the upper left quadrant. For example, these anchors may be too far from the mobile robot 1000 for their signals to be successfully received. It may be desirable for the mobile robot 1000 to receive positioning signals at a relatively high rate, and not using distant anchors may increase the rate at which the mobile robot 1000 may receive positioning signals.

[0233] Accordingly, in some embodiments, the schedule may be adjusted so that only anchors located within region A are used to transmit positioning signals. In other embodiments, the schedule may be adjusted so that a subset of anchors are used to provide positioning capabilities only in region A. Figure 19As shown in , as the position of the group of mobile robots 1000 changes over time, area A follows them through the four quadrants. As a result of these schedule changes, the area (area A) in which the mobile robots can locate themselves moves over time. Adjustment of the schedule can be achieved in several ways. In one case, the transmission schedule can be changed periodically based on the position of the group of mobile robots 1000. This can be achieved in an open loop manner, assuming that the central unit knows the target position of the mobile robots, or in a closed loop manner based on position information provided by the mobile robots. Therefore, different schedules can be used over time. In another, perhaps more complex example, the adjustment can be accomplished using a single long time schedule that is synchronized with the movement of the mobile robots (for example, the schedule can be started when the mobile robots start moving or a few seconds before the mobile robots start moving), and the single long time schedule has a duration that is at least as long as the duration of the mobile robots' trajectory.

[0234] although Figure 19 While adjusting the schedule based on the positions of one group of mobile robots is shown, the schedule may also be adjusted based on two or more groups of mobile robots. Figure 20 A schematic example of how to adjust a schedule for two groups of mobile robots according to some embodiments of the present disclosure is shown. In this case, the mobile robots are organized into two different groups that move according to different sets of trajectories.

[0235] This raises the technical question of how to configure a schedule to adapt and optimize the transmission of positioning signals. In some embodiments, it can be advantageous to organize the anchors of the positioning network into two clusters, and define a schedule in such a way that the first and second groups of mobile robots can independently receive data (e.g., commands) from the anchors and locate themselves. This can be achieved, for example, by using two different carrier frequencies for the two clusters or by setting the transmit power in such a way that transmissions from anchors assigned to the first group of mobile robots do not interfere with transmissions from anchors dedicated to the second group of mobile robots.

[0236] As shown in location map 2010a, the first group of mobile robots starts at the top of the space within cluster A, while the second group starts at the bottom within cluster B. The schedule may cause the first group of anchors (cluster A) to cover the area occupied by the first group of mobile robots and the second group of anchors (cluster B) to cover the area occupied by the second group of mobile robots.

[0237] As part of the target trajectory, the first group of mobile robots converged toward the center of the top portion of the space, while the second group of mobile robots separated and moved to the sides of the bottom portion. This is shown in location map 2010b. These movements, for example, did not require an update to the transmission schedule.

[0238] Next, the target trajectory may cause the first group of mobile robots to move toward the bottom section, while the second group of mobile robots moves toward the top section. This is shown in location map 2010C. To perform these maneuvers, the transmission schedule is updated to change the set of anchors belonging to cluster A and the set of anchors belonging to cluster B. This creates a central aisle for the first group of mobile robots and lateral corridors for the second group of mobile robots. It is worth noting that in some cases the spatial area covered by cluster B may overlap with the spatial area covered by cluster A.

[0239] Ultimately, the target trajectory might have the first group of mobile robots deployed in the bottom portion of the space, and the second group of mobile robots deployed in the upper portion. This is shown in position map 2010d. This is again achieved by redistributing the anchors in the two clusters.

[0240] The use case presents the concept that a cluster can move with a group of mobile robots to provide a desired positioning performance in the spatial area occupied by the individual mobile robot groups.

[0241] It will be appreciated that although described in the context of positioning for mobile robot 1000 Figure 18-20 , can be used in the case of any other suitable object, such as a vehicle, a person, or any other object comprising a self-positioning device for receiving a positioning signal Figure 18-20 In some embodiments, the present invention may be used with any of the embodiments of the transceiver 130 and the self-positioning device 140 described herein. Figure 18-20 .

[0242] Figure 21 2 is a diagram of a schematic structure of a positioning signal 202 according to some embodiments of the present disclosure. In some embodiments, the structure of the positioning signal 202 is similar to that defined in IEEE Standard 802.15.4. This same standard describes other aspects of the positioning system, such as the signal transmission process. The transmission of the positioning signal 202 is performed at time t start At 2122, the transmission of a preamble sequence 2110 begins. This sequence is typically predefined and known to both the transmitter (e.g., transceiver 130) and the receiver (e.g., self-positioning device 140) of positioning signal 202. In some embodiments, preamble sequence 2110 may be stored in memory. In some embodiments, preamble sequence 2110 may be configurable during system operation. In some embodiments, preamble sequence 2110 may be encoded by interconnecting digital or analog electronic components.

[0243] In some embodiments, preamble 2110 defines a sequence of radio pulses (e.g., UWB radio pulses) transmitted at a specific rate over a specific transmission channel. This rate may sometimes be referred to as a pulse repetition frequency (PRF). The PRF is typically known to both the transmitter and receiver of positioning signal 202. In some embodiments, the PRF may be stored in memory. In some embodiments, the PRF may be configurable during system operation. In some embodiments, the PRF may be encoded in the interconnections of digital or analog components.

[0244] If a receiver is configured to operate at the transmit center frequency, with the same transmit frequency bandwidth, the same preamble, and the same preamble modulation scheme (e.g., frequency or phase shift), the receiver is generally capable of receiving positioning signals (e.g., UWB signals). In some embodiments, this can be achieved by appropriately configuring the receiver's analog receive electronics (e.g., analog receive electronics 504) or digital receive electronics (e.g., digital receive electronics 506) or the transmitter's analog transmit electronics (e.g., analog transmit electronics 214) or digital transmit electronics (e.g., digital transmit electronics 216). In some embodiments, appropriate selection of the channel or preamble 2110 or pulse repetition frequency can enable the receiver to receive UWB signals from a specific subset of transmitters. In some embodiments, appropriate selection of the channel or preamble 2110 or pulse repetition frequency can enable the transmitter to transmit UWB signals to a specific subset of receivers. In some embodiments, appropriate selection of the channel or preamble 2110 or pulse repetition frequency can allow multiple positioning signals to be transmitted simultaneously with reduced or no interference.

[0245] After transmitting the preamble 2110, the transmitter transmits a start frame delimiter 2112 to indicate the start of the data portion of the signal. Following the start frame delimiter 2112, the transmitter transmits a physical layer header (PHR) 2114 containing information related to the encoding of the signal's payload 2116 (e.g., data rate). Following the physical header 2114, the signal's payload 2116 is transmitted. In some embodiments, the payload is empty. In some embodiments, the payload contains information from the global attribute sensor 228. In some embodiments, the payload 2116 contains information that facilitates synchronization by a synchronization unit (e.g., synchronization unit 510). In some embodiments, the payload 2116 contains information that enables a scheduling unit (e.g., scheduling unit 218) to schedule future transmissions. In some embodiments, the payload 2116 contains information that enables the self-positioning device to receive future transmissions (e.g., information about future signal transmissions, which may include the transmission time, transmission channel, transmission preamble, or transmission pulse repetition frequency). In some embodiments, payload 2116 includes information about a previously transmitted or received signal (e.g., signal 202 or 302). In some embodiments, payload 2116 includes other information. In some embodiments, payload 2116 may include multiple pieces of information. In some embodiments, payload 2116 includes error checking information that can be used to assess the integrity of received payload 2116. The transmission of a signal occurs at a time t after the transmission of payload 2116. end Ends at 2124.

[0246] By detecting and receiving the positioning signal's preamble 2110, the receiver can detect the transmission of a start-of-frame delimiter (SFD) 2112. In some embodiments, the time of detection of the start-of-frame delimiter 2112 is time-stamped by the receiver's digital receive electronics (e.g., digital receive electronics 506). After detecting the start-of-frame delimiter 2112, the receiver can detect the physical header 2114. The receiver can use the information encoded in the physical header 2114 to decode the information encoded in the signal's payload 2116.

[0247] In some embodiments, payload 2116 can be checked for errors. In some embodiments, payload 2116 can be used within other units of the receiver. In some embodiments, payload 2116 can be used to calculate time differences. In some embodiments, payload 2116 can be used to calculate distances. In some embodiments, payload 2116 can be compared with measurements from a global property sensor of the receiver (e.g., global property sensor 520). In some embodiments, payload 2116 can be stored in memory (e.g., memory 230, 516).

[0248] As will be clear to those skilled in the art, although this embodiment discloses a specific signal structure similar to the specific signal structure defined in IEEE standard 802.15.4, many other signal structures are equally effective and can be used with this disclosure.

[0249] Figure 22 A schematic transmission schedule 2200 is shown that can be used to achieve higher positioning updates according to some embodiments of the present disclosure. For example, the transmission schedule 2200 can be used when it is not crucial for the self-positioning device to receive each transmitted data payload. The transmission schedule 2200 is depicted in the form of a graph with time on the x-axis and transceiver numbers on the y-axis. As shown, the transmission schedule 2200 is determined such that transceiver 1 starts transmitting the preamble of the positioning signal 2202a at time t0. The transmission duration of the signal 2202a from transceiver 1 is T, and thus the transmission will complete at t2 = t0 + T. The preamble and SFD of the signal 2202a are transmitted during the first duration T'. Thus, the self-positioning device can time-stamp the reception time of the signal at time t1 = t0 + T'.

[0250] At time t3, the transmission of the positioning signal 2202b from transceiver 2 is scheduled. In a traditional schedule, t3>t2 would be chosen such that the self-positioning device can fully receive the signal from transceiver 1 before transmitting the second positioning signal. However, in this example, T3 is deliberately chosen such that t0<t3<t2 (i.e., the transmission of the signal 2202b from transceiver 2 starts after transceiver 1 starts its transmission but before it completes its transmission). In some embodiments, the transmission will be scheduled such that t1 <t3 <t2.

[0251] The schedule 2200 allows the self-positioning device receiving the signals of the positioning system to make a choice around or prior to time t1 as to whether it is more beneficial for its performance to: (1) fully receive the signal 2202a from transceiver 1 by keeping the receiving electronics of the self-positioning receiving device tuned to the signal 2202a throughout the duration T, or (2) only time-stamp the signal from receiver 1 but ignore its payload, and instead also time-stamp the signal 2202b from receiver 2 by tuning to the signal from transceiver 1 during the duration T' and then aborting the reception and tuning to the signal 2202b from transceiver 2.

[0252] The schedule 2200 shows two additional signal transmissions 2202c, 2202d from the respective transceivers 3, 4, where the self-positioning device making the reception can make a similar choice for reception.

[0253] In order for a self-locating device to selectively time-stamp a signal without receiving the entire signal, the analog or digital receiving electronics in the self-locating device must be operable to receive a signal by which reception of the signal from the antenna can be limited to time-stamping the preamble and SFD portions. In some embodiments, the digital receiving electronics provide a signal to an interface to stop ongoing signal reception when time-stamping has been completed; this signal and the interface can then be used in conjunction to stop receiving the signal after time-stamping has been completed. In some embodiments, the digital receiving electronics provide an interface where they can be configured to automatically stop receiving once time-stamping has been completed.

[0254] Figure 23 Some embodiments of the present disclosure are shown Figure 22 A portion of an illustrative transmission schedule and corresponding receiver activities 2310. Figure 23 Further details of the operation of the receiver of the self-positioning device when the positioning signals are scheduled to partially overlap are shown. In particular, Figure 23 Shown Figure 21 Corresponding exemplary receiver activity 2310 is shown below the positioning signals 2202a, 2202b.

[0255] Prior to time t0, the receiver scans for preambles. Shortly after the preamble transmission from the first transceiver begins at time t0, the receiver begins locking onto the preamble sequence of positioning signal 2202a. After the transmission of the preamble and SFD is complete, the receiver (e.g., digital receive electronics) has time-stamped the receipt of positioning signal 2202a. At this point, the receiver stops receiving signals from transceiver 1 and begins scanning for a new preamble. Shortly after transmitter 2 begins transmitting the preamble of positioning signal 2202b at time t3, the receiver locks onto the preamble sequence. The receiver then remains locked onto positioning signal 2202b to receive the entire signal from transceiver 2, generate a receive timestamp, and receive the data payload of that signal.

[0256] In some embodiments, the self-positioning device includes decision logic that determines whether it is more advantageous to receive the positioning signal in its entirety or only the portion required for time-stamping. For example, this decision can be based on a minimum required payload reception frequency, a list of positioning anchors from which payloads must be received (while other anchors can only be time-stamped), or logic that monitors whether sufficient information (such as which anchors transmitted them, at what time, etc.) is available to interpret only time-stamped signals.

[0257] In some embodiments, the self-locating device includes a scheduling unit that configures the receiver to receive the signal in its entirety or to time-stamp the signal only according to a schedule stored in memory. In some embodiments, the payload of the positioning signal includes a schedule of future transmissions, and the self-locating device uses the schedule to determine whether to time-stamp only or to receive the future positioning signal in its entirety.

[0258] Figure 24 An exemplary transmission schedule of positioning signals 2402a, 2402b, 2402c including two payloads is shown according to some embodiments of the present disclosure. Figure 24 The transmission schedule is similar to Figure 22 However, instead of a single payload, the payload of the positioning signal is organized into two parts. The first part of the payload (payload 1) can contain all or most of the information that the self-locating device wants to receive, while the second part of the payload (payload 2) can contain only some of the information that the self-locating device is interested in.

[0259] Before time t0, the receiver of the self-locating device scans for the preamble received shortly after time t0. From this point on, the receiver can lock onto signal 2402a, receive the SFD, and time-stamp the message. Some receivers may decide that this information is sufficient and therefore stop receiving and begin scanning for a new preamble. Other receivers may be interested in receiving more information and therefore continue receiving until the first portion of the payload (Payload 1) is completely received. At this point, these receivers can decide whether to continue and receive the remainder of the payload (Payload 2) or interrupt reception and begin scanning for a new preamble.

[0260] Figure 24 The schedule shown in allows a self-locating device to decide how much information to receive and how often it needs to be received. For example, some self-locating devices may wish to receive the second portion of the payload for every fourth incoming positioning signal, the first portion of the payload for every second incoming positioning signal, and the SFD (e.g., message time stamp) for every incoming signal or whenever possible. This allows for faster time stamping of incoming signals compared to a receiver that always receives the entire positioning signal.

[0261] In some embodiments, the payload of the positioning signal may be organized into three or more parts, and the self-positioning device may determine which part to receive.

[0262] Figure 25An exemplary positioning system 2500 and a corresponding performance map 2510 according to some embodiments of the present disclosure are shown. The positioning system 2500 includes 12 anchors labeled A through L. The performance map 2510 indicates that the positioning performance of the entire positioning space of the positioning system 2500 is 1. Therefore, the performance map 2510 indicates that the same positioning performance should be provided for the entire positioning space.

[0263] Anchors A through L of the positioning system 2500 can be configured (e.g., using a schedule determined by a scheduler) to transmit positioning signals according to any of a number of different schedules to achieve similar positioning performance within the positioning area. In one example, the anchors can be scheduled to transmit in alphabetical order (i.e., ABCDEFGHIJKL). In another example, the anchors can be scheduled to transmit in such a way that transmissions from anchors located on the ground are followed by transmissions from anchors located on the ceiling (e.g., ALCKDHEGFJBI). This may be desirable to maximize the difference in the direction in which a self-positioning device receives positioning signals, thereby optimizing the positioning performance of the self-positioning device by minimizing dilution of precision. Notably, these two schedules are spatially and transmission rate-consistent. It should also be noted that these schedules are merely illustrative, and other schedules can be used to achieve the same positioning performance within the positioning space.

[0264] Figure 26 The following diagram shows the use of different performance maps 2610 according to some embodiments of the present disclosure. Figure 25 Schematic positioning system 2500. Performance map 2610 with Figure 25 The difference between performance map 2510 and performance map 2610 is that performance map 2610 only requires positioning in the right portion of the positioning space. The left portion of the positioning space is not required. For example, performance map 2610 can be used when there is no self-positioning device in the left portion of the positioning space.

[0265] To achieve the desired positioning performance for the performance map 2610, a subset of anchors can be configured (e.g., using a schedule determined by a scheduler) to transmit positioning signals according to any one of a number of different schedules to achieve the desired positioning performance. For example, the anchors can be configured so that anchors on the left side of the positioning space do not transmit positioning signals. The resulting transmission schedule has the advantage of providing a faster transmission rate for anchors covering the right side of the positioning space. Similar to Figure 25,The transmission order can be alphabetical (i.e., BCEFHIKL) or more complex (e.g., BLEIFHCK).,It is noteworthy that the two schedules are consistent in ,transmission rate, but are inconsistent in positioning space.

[0266] Figure 27 27 shows an exemplary positioning system 2700 and a corresponding performance map 2710 according to some embodiments of the present disclosure. The positioning system 2700 includes five anchors labeled A through E. The distribution of anchors in the positioning system 2700 is different from Figure 25 The distribution in the positioning system 2500 in FIG. 25 is different because the number of anchors mounted on the ground is different from the number of anchors mounted on the ceiling. The performance map 2710 indicates that the expected positioning performance is consistent in the positioning space.

[0267] In practice, evenly distributing anchors within a positioning space can be difficult. For example, in some installations, it may be more practical to install a larger number of anchors on the ceiling and a smaller number on the ground. Positioning system 2700 illustrates this situation. If all anchors in system 2700 transmit positioning signals at the same rate, positioning performance may be reduced compared to a system with evenly distributed anchors, as four out of five positioning signals will originate from the ceiling. To mitigate the effects of an uneven distribution of anchors, as in positioning system 2700, a transmission schedule can be defined such that anchors located on the ground transmit more frequently than anchors located on the ceiling. For example, the transmission of positioning signals can be alternating between the ground and ceiling, so that the transmission rate of positioning signals originating from anchors on the ground is the same as the transmission rate of positioning signals originating from anchors on the ceiling. For example, a suitable transmission order for positioning system 2700 is: AE, DE, BE, CE. Note that this schedule is consistent across the space, but the transmission rates are inconsistent (i.e., different anchors have different transmission rates).

[0268] Figure 28 The following diagram shows the use of different performance maps 2810 according to some embodiments of the present disclosure. Figure 25 Schematic positioning system 2500. Performance map 2810 is different from Figure 25 The performance map 2810 is used because different levels of positioning performance are required within the positioning space. Specifically, higher positioning performance is required in the right portion of the positioning space than in the left portion. For example, the performance map 2810 can be used when most self-positioning devices are located in the right portion of the positioning space. As another example, the performance map 2810 can be used when there are more obstacles in the right portion of the positioning space, and therefore higher performance is desired to reduce the chance of collision with obstacles.

[0269] Different levels of positioning performance can be achieved by configuring the anchors in such a way that anchors on the left side of the coverage space transmit less frequently than anchors on the right side of the coverage space. For example, a suitable transmission order is: BLEIFHCKALCKDHEGFJB, which results in a transmission rate twice as fast for anchors on the right side of the coverage space. Another suitable transmission order is: BLEIAFHCKJBLEIDFHCKG, which also results in a transmission rate twice as fast for anchors on the right side of the coverage space.

[0270] Figure 29 2900 shows a schematic transmission schedule of a positioning signal according to some embodiments of the present invention. Figure 25 The more complex transmission schedule of the positioning system 2500, which realizes the Figure 28 The expected positioning performance reflected in the performance map 2810 of . Schedule 2900 includes 9 rows of information. Row 1 indicates the time slot. Rows 2-5 indicate the transmission parameters for the first set of positioning signals to be transmitted according to the schedule, and rows 6-9 indicate the transmission parameters for the second set of positioning signals to be transmitted according to the schedule. Rows 2 and 6 identify the anchors. Rows 3 and 7 identify the transmission carrier frequency. Rows 4 and 8 indicate the preamble. Rows 5 and 9 indicate the transmit power. Therefore, schedule 2900 differs from the previous exemplary schedules in that it not only specifies the anchor transmission order, but also specifies additional transmission parameters such as carrier frequency, preamble, and transmit power. The goal of schedule 2900 is to achieve high performance in high performance areas with less impact on low performance areas.

[0271] Schedule 2900 can be considered to have two sub-schedules that are time synchronized. Row 1 shows the time slots in which the sub-schedules are organized. Rows 2-5 can be considered to constitute the first sub-schedule, which is for Figure 25 The optimization sequence discussed. Lines 6-9 can be considered to constitute a second sub-schedule that defines additional transmissions for anchors surrounding high-performance areas. In this configuration, the first sub-schedule achieves consistent coverage throughout space, and the second sub-schedule improves positioning performance in high-performance areas.

[0272] During time slot T1, anchor A transmits a signal at the same time as anchor E. Because the two anchors transmit on different frequencies, the self-locating device can choose to receive from either anchor A or anchor E to optimize its positioning performance based on the self-locating device's location. This can be achieved by having the self-locating device receive data representing possible choices for the anchor transmitting in that time slot. This data can be received from a remote location (e.g., as part of the payload of an earlier positioning signal) or retrieved from memory using a pre-known transmission sequence. The selection can be made in real time (e.g., by calculating the predicted reduction in precision that can be achieved by receiving either signal) or pre-calculated (e.g., based on the current location, stored in memory as a map of preferred transceivers). Similar selection can be performed during time slots T5 and T10, where two different anchors transmit positioning signals on different frequencies.

[0273] During time slot T6, anchor H transmits two signals simultaneously. The second signal is sent at a different frequency than the first and includes a longer preamble, which allows it to be received at a greater distance and with more precise time-stamping. As shown, the second signal's longer preamble may cause it to be transmitted during more than one time slot. Thus, the self-locating device can choose to receive signals from anchors H and E, which transmit during time slots T6 and T7 on frequency 1, or the more precisely time-stamped signal from anchor H, which transmits during both time slots T6 and T7 on frequency 2. In this example, anchor H includes a pair of transceivers. A similar principle, which does not require an anchor with a pair of transceivers, is used in time slots T11 and T12.

[0274] During time slot T8, anchor G transmits on the same frequency and at the same time as anchor C. In this case, anchor C's parameters are adjusted to avoid interference, anchor C transmits at a lower transmit power, and can only be received by devices outside the range of anchor G (including self-locating devices and other anchors).

[0275] It will be understood that Figure 29 The timetables depicted in FIG are merely illustrative and other variations may be used. In one variation, the first timetable (i.e., rows 2-5) may be altered so that all transmissions use a longer preamble length in anticipation of the transmission of the preamble. For example, it may be configured to transmit at time slot T K An anchor transmitting during the time slot T K-1 The self-positioning device can therefore choose to receive the entire preamble or only the preamble in time slot T K The first option allows the transmission of the preamble part during the time slot T K The first option allows for a more precise time stamp of the transmitted positioning signal, while the second option allows the self-positioning device to receive both positioning signals.

[0276] Figure 30 Another exemplary transmission schedule 3000 for positioning signals according to some embodiments of the present disclosure is shown. Schedule 3000 represents another complex transmission schedule. Schedule 3000 specifies even more configuration parameters than those specified in schedule 2900. Schedule 3000 specifies the transmission time for reception or transmission, the anchor mode (i.e., reception or transmission), the carrier frequency, the preamble, the preamble length, the transmit power, and the antennas used for reception or transmission. Schedule 3000 specifies the configuration parameters for three transceivers (A, B, and C) and is organized by time slots (T1, T2, T3, T4, and T5).

[0277] Anchor A transmits during time slots T1 and T4. Anchor B transmits during time slots T2 and T5. Anchor C transmits during time slot T3. When anchors are not transmitting, they are configured to receive positioning signals transmitted by other anchors.

[0278] Anchor A always operates on frequency F1. Anchor B operates on frequency F1 during time slots T2, T3, and T5, and on frequency F2 during the remaining time slots. Anchor C operates on frequency F1 during time slots T1 and T2, and on frequency F2 during the remaining time slots. Using different frequencies allows for multiple transmissions to occur simultaneously (not shown in timetable 3000).

[0279] Anchor A always uses preamble 1. Anchor B uses preamble 5 during time slots T1 and T5, and preamble 1 during the rest of the time slots. Anchor C always uses preamble 5. Using different preambles allows for multiple transmissions to occur simultaneously (not shown in schedule 3000).

[0280] Anchors A and C always transmit positioning signals with a preamble length of 250 microseconds. Anchor B always transmits positioning signals with a preamble length of 500 microseconds. As mentioned above, a longer preamble length allows the positioning signal to be received at a greater distance and with a more accurate time stamp.

[0281] Anchor A always transmits a positioning signal at a transmit power of 5 dBm. Anchors B and C always transmit a positioning signal at a transmit power of 0.5 dBm. Using different transmit powers allows for transmissions with longer or shorter coverage. This can be used to achieve simultaneity without interfering with transmissions from different anchors using the same frequency and preamble.

[0282] Anchor A always uses antenna 1 to receive and transmit positioning signals. Anchor B always uses antenna 1 to transmit and antenna 2 to receive. Anchor C uses antenna 2 during the first three time slots and antenna 1 during the last two time slots. Using different antennas allows for transmissions with different radiation patterns (i.e., reaching different areas of space with different signal qualities) and allows for better reception.

[0283] Self-positioning devices can use the knowledge encoded in the schedule to configure their own reception parameters to receive data from specific transmitters. For example, a self-positioning device can choose to receive specific signals to optimize its positioning performance based on its location.

[0284] In some embodiments, anchors may be configured (as part of schedule 3000) to receive specific signals to improve network clock synchronization or information propagation over the network.

[0285] Figure 31 A schematic flow diagram 3100 illustrating logic that may be implemented on a self-locating device to configure its receiver based on a received payload identifying future transmissions, according to some embodiments of the present disclosure.

[0286] In step 3102, the self-positioning device may read raw reception data from the digital receiving electronics upon receiving the positioning signal. This reading process may be implemented using a digital transmission protocol (eg, SPI, I2C, UART, or parallel digital protocol).

[0287] At step 3104, after reading the data, the self-locating device may decode the received payload. Decoding may include multiple processing steps (not shown). For example, such processing may include: deserializing the data, parsing data indicating the payload size, parsing data indicating the payload type, any other processing steps, or any combination thereof.

[0288] At decision 3106, a data integrity check may be performed. For example, a CRC checksum may be verified. If the data integrity check fails (e.g., if the CRC checksum is incorrect), the self-locating device may discard the received data at step 3108, and the process may return to step 3102. If the integrity check succeeds, the process may continue to decision 3110.

[0289] At decision 3110, the contents of the payload may be examined to determine whether it contains a payload identifying a future transmission via the location anchor. In some embodiments, step 3110 may be the final step in pre-processing the payload. If the payload is found not to identify a future transmission, the process may terminate at step 3112 and return to step 3102. If the payload is found to identify a future transmission via the location anchor, the process may continue to decision 3114.

[0290] At this time, the self-positioning device can perform a step for determining which available positioning signal to preferably receive. For example, this decision can be performed based on the status information provided by the locator.

[0291] At decision 3114, the self-positioning device may determine whether the locator has been successfully initialized (i.e., whether the locator has a current estimated location). If the self-positioning device determines that the locator has not been successfully initialized, the process may proceed to step 3120. If the self-positioning device determines that the locator has been successfully initialized, the process may proceed to step 3116.

[0292] At step 3120, when the locator is not initialized, the self-positioning device may make a decision about which signal to receive based on a backup heuristic. For example, the self-positioning device may decide to receive the signal that provides the widest coverage to determine the initial position estimate. The process may then proceed to step 3122.

[0293] At step 3116, when the locator is initialized, the self-positioning device may perform a first check based on the self-positioning device's estimated position. This position may be compared with the positions of positioning anchors that will transmit signals in future time slots. If good reception is not possible for some of these anchors at the self-positioning device's location, they are marked as non-preferred signals. In some embodiments, this check may also take into account the orientation of both the anchor antenna and the self-positioning device antenna to more accurately estimate reception quality. In some embodiments, the metric used to determine what estimated reception quality is acceptable may also be adjusted based on other metrics, such as how important the acquired signal is to the quality of the position estimate.

[0294] At step 3118, the quality of the locator's position estimate can be examined. The quality can be expressed, for example, as the current dilution of precision or as the variance of the position estimate. Based on the possible range of positions of the self-locating device, the reduction in uncertainty for each candidate positioning signal can be calculated. For example, simulated versions of future positioning signals can be provided to the locator to evaluate the change in variance. These evaluations can be performed for each candidate positioning signal, and then a metric can be applied to determine the preferred positioning signal. In some embodiments, such a metric can be the root mean square of the total position variance, the total variance in a plane, or the variance along a particularly important direction. The process can then proceed to step 3122.

[0295] After the above steps are performed, the preferred positioning signal to be received has been determined. At step 3122, the receiver settings are determined. However, the payload may already provide high-level information about the configuration of the future positioning signal, so more low-level receiver settings may generally be required to configure the receiving electronics. In some embodiments, these low-level receiver settings may be hardware-dependent settings. For example, the hardware-dependent settings may include the configuration of the phase-locked loop in the receiving electronics, the preamble used to scan during reception, the position of the RF switch, at least one of other hardware settings, or any combination thereof. In some embodiments, the receiver settings may be stored in a memory in the form of a lookup table to allow the self-locating device to determine the correct low-level configuration from the received high-level information.

[0296] At step 3124, a low-level receiver configuration may be applied to the receiver. In some embodiments, the configuration may be applied by writing configuration parameters to registers of the receiving electronics via a protocol such as SPI, I2C, or UART. In some embodiments, the configuration may be applied by changing the value of a digital or analog input pin of the transmitting electronics, for example, by changing the state of an output pin of a microcontroller.

[0297] In some embodiments, status information from the locator can be used to determine which positioning signal to receive. In some embodiments, many other decision criteria can be used for the same purpose. For example, the decision can be made based on the known planned movement of the self-locating device, based on the signal strength of the received positioning signal, based on a stored positioning signal priority list, based on other criteria, or any combination thereof.

[0298] It should be understood that the steps and decision elements of flowchart 3100 are merely illustrative and can be modified in various ways within the scope of the present disclosure. For example, in some embodiments, the top portion of flowchart 3100 can be performed independently of the bottom portion. For example, logic elements 3102-3112 can be performed for each received signal, while logic elements 3114-2124 can be selected individually and repeatedly based on which signal is received. As another example, in some embodiments, logic elements 3102-3112 may not need to be performed when the self-positioning device stores a schedule of when the anchor is scheduled to transmit positioning signals.

[0299] Figure 32 An exemplary application of performance graphs according to some embodiments of the present disclosure to an indoor and outdoor environment 3200 in which aircraft operate is shown. The environment includes an indoor area within a building 3210 (e.g., a warehouse) with an access area 3220 through which aircraft 3230 can enter and exit the outdoor area. In this example, two positioning systems have been installed: one is installed outdoors, and the second is installed indoors.

[0300] Required positioning performance is identified in different regions of the environment. Landing zone 3240 surrounds the landing area of ​​aircraft 3230. This region is marked as requiring particularly high positioning performance because tight flight tolerances may be required during landing. A second region 3250 covers most of the remaining indoor space and requires a positioning performance level sufficient for normal safe flight. The remainder of the indoor space has no positioning performance requirements because the aircraft does not operate in these spaces.

[0301] Since the flight maneuvering space is reduced in the access area 3220 connecting the indoor and outdoor areas, a particularly high positioning performance is required in the second area surrounding the access area 3220. Normal positioning performance is required in the remaining outdoor areas from the approach area to the access area, while no positioning performance is required in other areas.

[0302] in addition, Figure 32 The availability of other positioning mechanisms (in this case, GPS) is shown. The availability of these mechanisms can also be provided to the scheduler. If the self-positioning device is configured to fuse different positioning systems (such as the system disclosed herein and GPS) to enhance performance, the scheduler can take this into account and adjust its positioning performance requirements to achieve the desired overall positioning performance, assuming that other positioning mechanisms can be used as supporting tools. For example, when aircraft 3230 is operating above a building, GPS can provide sufficient positioning performance without the positioning system described herein, and therefore the plan does not need to consider coverage in that area.

[0303] Figure 32 The use of a bridging anchor is also shown, where the bridging anchor is used to allow the aircraft to seamlessly transition between indoor and outdoor positioning systems.

[0304] Figure 33 Also shown are two exemplary positioning networks 3310 and 3320, according to some embodiments of the present disclosure. Positioning network 3310 partially overlaps with positioning network 3320. In some embodiments, positioning network 3310 includes multiple synchronized anchors, and positioning network 3320 includes multiple synchronized anchors. However, because positioning networks 3310 and 3320 are different networks, they may be out of sync with each other. Consequently, it may be difficult for a self-positioning device to move between positioning networks 3310 and 3320. To address this issue, one or more bridging anchors can be used to enable a self-positioning device to switch from one network to another. As illustrated, two bridging anchors 3330 are located in the overlapping region between the two networks.

[0305] Figure 34 33 is a block diagram of an exemplary bridging anchor configured to enable synchronization of two positioning systems (e.g., positioning networks 3310 and 3320) according to some embodiments of the present disclosure. When two separate positioning systems are used in close proximity to each other, a self-positioning device that switches from receiving signals from the first system to receiving signals from the second system (e.g., because it moves from a location where the first system provides better performance to a location where the second system provides better performance) typically needs to reinitialize its positioning unit to recognize the timing information of the second positioning system and then determine its position again. This can result in an outage during which positioning is unavailable (or only a degraded positioning is available) as the self-positioning device switches from one network to the next. Figure 34 The bridge transceiver shown in allows synchronization of timing information between two adjacent networks, enabling a self-locating device to switch between networks while maintaining its local timing information as if it were still receiving positioning signals from the first network.

[0306] Like some anchors disclosed herein, the bridging anchor includes a clock 210, a scheduling unit 218a, digital transmission electronics 216a, analog transmission electronics 214a, an antenna 212a, analog reception electronics 220a, and digital reception electronics 222a. These components are used by the bridging anchor to communicate with the first positioning system and provide positioning signals for the first positioning system.

[0307] To enable bridging functionality, the bridging anchor in this embodiment includes a second set of components for the first positioning system. Specifically, the bridging anchor here additionally includes a scheduling unit 218b, digital transmission electronics 216b, analog transmission electronics 214b, antenna 212b, analog reception electronics 220b, and digital reception electronics 224b. These additional components are configured to receive and transmit signals from the second positioning system.

[0308] The bridging anchor in this embodiment also includes a synchronization unit 224a coupled to the digital receiving electronics 222a and the clock 210. The synchronization unit 224a determines timing information for the first positioning system. The bridging anchor herein also includes a synchronization unit 224b to similarly determine timing information for the second positioning system. Additionally, the synchronization unit 224b receives the timing information from the synchronization unit 224a to compare the timing information from the two positioning systems. The synchronization unit 224b is coupled to the scheduling unit 218b and can adjust the scheduling operation of the second positioning system by at least one of: (1) adjusting the scheduling of the second positioning system so that the second positioning system is directed to synchronize with the scheduling of the first positioning system, and (2) including information in the transmission payload that causes the anchors in the second positioning system to adjust their timing to the timing of the first positioning system. The timing information referred to in this context can be, for example, the apparent clock rate, apparent clock offset, or apparent clock skew of the positioning system.

[0309] Figure 35 is a block diagram of another exemplary bridging anchor configured to enable seamless transition of a self-locating device from one positioning system to another positioning system according to some embodiments of the present disclosure. Figure 34 The bridging anchor is different. Figure 35 The bridging anchor does not share common timing information between the two positioning systems to synchronize them with each other. Figure 35 The bridge anchor needs to provide a seamless transition between two unsynchronized positioning systems. The difficulty that causes the positioning of the self-positioning device to be temporarily unavailable (or degraded) is that in order to provide meaningful positioning data, the self-positioning device needs to recognize the timing of the second positioning system when the positioner is reinitialized. Figure 35 The bridge transceiver shown in allows a self-positioning device to quickly switch from a first positioning system to a second positioning system by warm starting its locator after reinitialization using additional timing information from the second positioning system.

[0310] To achieve this goal, Figure 35The bridge transceiver includes analog receive electronics 220 and digital receive electronics 222 coupled to antenna 212, which receives signals from the second positioning system. Digital transmit electronics 216 and analog transmit electronics 214 are configured to transmit signals configured for the first positioning system. The receive and transmit electronics share a common clock 210. The signal received from digital receive electronics 222 is provided to a synchronization unit 224, which identifies timing information for the received signal (which is from the second positioning system). This identified timing information is sent to a scheduling unit 218, which may include it in a payload transmitted on the first positioning system. A self-positioning device receiving the signal from the first positioning system can decode this timing information and use it to hot-start a locator for the second positioning system when switching from the first positioning system to the second.

[0311] According to one aspect of the present disclosure, a positioning system is provided that includes a plurality of positioning anchors configured to wirelessly transmit positioning signals. The positioning signals may be used by a self-positioning device within an area to determine location information. For example, a self-positioning device may use the positioning signals to determine its own position within a defined three-dimensional area.

[0312] In some embodiments, the plurality of positioning anchors may include a first positioning anchor, a second positioning anchor, and a third positioning anchor. The first positioning anchor may be configured to wirelessly transmit a first positioning signal. The second positioning anchor may be configured to wirelessly transmit a second positioning signal. The third positioning anchor may be configured to wirelessly transmit a third positioning signal.

[0313] In some embodiments, each of the plurality of positioning anchors may be communicatively coupled to a scheduling unit. In some embodiments, the scheduling unit may be configured to schedule the transmission of positioning signals. For example, the scheduling unit may schedule the transmission of a first positioning signal, a second positioning signal, and a third positioning signal. In some embodiments, the scheduling unit may schedule the transmission of positioning signals to control positioning performance. For example, the scheduling unit may schedule the first positioning anchor to transmit the first positioning signal at a first transmission rate, schedule the second positioning anchor to transmit the second positioning signal at a second transmission rate, and schedule the third positioning anchor to transmit the third positioning signal at a third transmission rate. In some embodiments, the first transmission rate may be greater than the second transmission rate. In some embodiments, the first transmission rate, the second transmission rate, and the third transmission rate may be selected to provide higher positioning performance within a portion of the area.

[0314] In some embodiments, the scheduling unit can be configured to adjust the transmission rate of any one of the first, second, and third positioning signals, or any combination thereof, to change positioning performance within an area during operation. In some embodiments, the scheduling unit can be configured to receive the location of the self-positioning device and / or the flight mode of the self-positioning device. In some embodiments, the scheduling unit can be configured to adjust the transmission rate based on the known location of the self-positioning device. In some embodiments, the scheduling unit can be configured to adjust the transmission rate based on the known movement of the self-positioning device (e.g., flight mode).

[0315] In some embodiments, each of the first, second, and third positioning signals may include an ultra-wideband (UWB) positioning signal. Each UWB positioning signal may include a preamble and a payload. In some embodiments, some UWB positioning signals may include a payload containing a command. In some embodiments, the scheduling unit may be configured to schedule transmission of the UWB positioning signals to optimize propagation of the command to at least one of the self-positioning device and the plurality of anchors.

[0316] In some embodiments, each of the plurality of positioning anchors may include a clock. In some embodiments, some UWB positioning signals may include a payload containing synchronization data. Each of the plurality of positioning anchors may be configured to receive synchronization data from a UWB positioning signal received from at least one other positioning anchor. In some embodiments, at least one scheduling unit may be configured to schedule the transmission of the UWB positioning signals to optimize clock synchronization.

[0317] In some embodiments, clock synchronization can be optimized by including an objective function or constraint that can represent clock synchronization performance. For example, such an optimization can include a model that predicts timestamp variability based on environmental effects, with the goal of achieving a high communication rate between anchors with low timestamp variability.

[0318] In some embodiments, each of the plurality of positioning anchors may include a synchronization unit, wherein each synchronization unit may be configured to calculate a correction for at least one of a clock offset and a clock rate for its corresponding clock based on the received synchronization data.

[0319] In some embodiments, the scheduling unit can be configured to schedule the transmission of positioning signals to increase at least one of precision, accuracy, or update rate in one or more portions of the area. In some embodiments, the scheduling unit can be configured to schedule the transmission of positioning signals based on time slots in a schedule. In some embodiments, the first positioning anchor can be allocated more time slots in the schedule than the second positioning anchor.

[0320] In some embodiments, the scheduling unit may include a first scheduling unit, a second scheduling unit, and a third scheduling unit. The first scheduling unit may be physically coupled to the first positioning anchor and may be configured to schedule the transmission of a first positioning signal. The second scheduling unit may be physically coupled to the second positioning anchor and may be configured to schedule the transmission of a second positioning signal. The third scheduling unit may be physically coupled to the third positioning anchor and may be configured to schedule the transmission of a third positioning signal.

[0321] In some embodiments, a method for transmitting a positioning signal in a positioning system is provided. In some embodiments, the positioning system may include a plurality of positioning anchors.

[0322] In some embodiments, the method may include a first positioning anchor of the plurality of positioning anchors wirelessly transmitting a first positioning signal during two or more time slots of the transmission schedule. The method may also include a second positioning anchor of the plurality of positioning anchors wirelessly transmitting a second positioning signal during one or more time slots of the transmission schedule. The method may also include a third positioning anchor of the plurality of positioning anchors wirelessly transmitting a third positioning signal during one or more time slots of the transmission schedule.

[0323] In some embodiments, the first positioning signal, the second positioning signal, and the third positioning signal may be usable by self-positioning devices within the area to determine location information. The first positioning anchor may be allocated more time slots in the transmission schedule than the second positioning anchor to provide higher positioning performance within a portion of the area.

[0324] In some embodiments, the method may include one or more scheduling units that adjust, during operation, the number of time slots allocated to the first, second, and third location anchors in a transmission schedule. In some embodiments, the method may include wirelessly receiving a known location of the self-positioning device. In some embodiments, the number of time slots may be adjusted based on the known location of the self-positioning device.

[0325] In some embodiments, the time slots of the transmission schedule can be allocated based on one or more of: a known location of the self-locating device; optimization of propagation of commands included as part of at least some of the first, second, and third positioning signals; optimization of synchronization of clocks associated with the first, second, and third positioning anchors, and at least one of improved precision, accuracy, or update rate in one or more portions of the area.

[0326] In some embodiments, the method may further include using a first clock to generate a first timing signal for determining when the first positioning anchor wirelessly transmits a first positioning signal. The method may further include using a second clock to generate a second timing signal for determining when the second positioning anchor wirelessly transmits a second positioning signal. The method may further include using a third clock to generate a third timing signal for determining when the third positioning anchor wirelessly transmits a third positioning signal, wherein the first, second, and third clocks are synchronized.

[0327] According to another aspect of the present disclosure, a positioning system is provided that includes a plurality of positioning anchors that can be configured to wirelessly transmit positioning signals that can be used by self-positioning devices within an area to determine position information. In some embodiments, the area can include a three-dimensional area.

[0328] In some embodiments, the positioning system may further include at least one scheduling unit. The at least one scheduling unit may be communicatively coupled to a plurality of positioning anchors. In some embodiments, the at least one scheduling unit may be configured to schedule the transmission of positioning signals according to a first transmission schedule. The first transmission schedule may define a first time order for each of the plurality of positioning anchors to transmit positioning signals. In some embodiments, the positioning signals may include ultra-wideband (UWB) positioning signals. In some embodiments, each positioning signal may include a preamble and a payload.

[0329] In some embodiments, the at least one scheduling unit may be configured to determine when to change from a first transmission schedule to a second transmission schedule. The second transmission schedule may define a second time sequence for transmitting positioning signals for each of the plurality of positioning anchors. The second transmission schedule may define a second transmitter (TX) or receiver (RX) mode for each of the plurality of positioning anchors. In some embodiments, the second time sequence may be different from the first time sequence. In some embodiments, the second time sequence may be the same as the first time sequence.

[0330] In some embodiments, the at least one scheduling unit can be configured to determine when to restart the transmission schedule. In some embodiments, the at least one scheduling unit can be configured to start or restart the transmission schedule from a specific time (i.e., the schedule does not start or restarts from the start of the schedule). In some embodiments, the first transmission schedule and the second transmission schedule can provide at least one of increased precision, accuracy, and update rate in different portions of the area.

[0331] In some embodiments, the at least one scheduling unit can be configured to, in response to determining to change from the first transmission schedule to the second transmission schedule, schedule the transmission of the positioning signal according to the second transmission schedule. In some embodiments, the change from the first transmission schedule to the second transmission schedule can change positioning performance within the area.

[0332] In some embodiments, the at least one scheduling unit can be configured to receive a known location of the self-positioning device and / or a flight pattern of the self-positioning device. In some embodiments, the at least one scheduling unit can be configured to determine when to change from a first transmission schedule to a second transmission schedule based on the known location of the self-positioning device. In some embodiments, the at least one scheduling unit can be configured to determine when to change from a first transmission schedule to a second transmission schedule based on user input. In some embodiments, the at least one scheduling unit can be configured to determine when to change from a first transmission schedule to a second transmission schedule based on a known movement of the self-positioning device.

[0333] In some embodiments, the payload of at least some of the UWB positioning signals may include commands. In some embodiments, the at least one scheduling unit may be configured to change from a first transmission schedule to a second transmission schedule to optimize propagation of commands to at least one of the self-positioning device and the plurality of anchors.

[0334] In some embodiments, each of the plurality of positioning anchors may include a clock. In some embodiments, the payload of at least some of the UWB positioning signals may include synchronization data. Each of the plurality of positioning anchors may be configured to receive synchronization data from a UWB positioning signal received from at least one other positioning anchor. The at least one scheduling unit may be configured to change from a first transmission schedule to a second transmission schedule to optimize for synchronization of the clocks.

[0335] In some embodiments, each of the plurality of positioning anchors may include a synchronization unit. Each synchronization unit may be configured to calculate a correction for at least one of a clock offset and a clock rate for its corresponding clock based on the received synchronization data.

[0336] In some embodiments, the first transmission schedule and the second transmission schedule may each include multiple time slots. In some embodiments, at least one of the plurality of location anchors may be assigned a different number of time slots in the first transmission schedule and the second transmission schedule. In some embodiments, at least one of the plurality of location anchors may be assigned a different transmitter (TX) mode or receiver (RX) mode. In some embodiments, at least one of the plurality of location anchors may be assigned a different transmitter (TX) mode or receiver (RX) mode in the first transmission schedule and the second transmission schedule.

[0337] In some embodiments, the at least one scheduling unit may include multiple scheduling units. In some embodiments, each of the multiple scheduling units may be physically coupled to a corresponding one of the multiple positioning anchors. In some embodiments, each of the multiple scheduling units may be configured to schedule transmission of positioning signals for its respective positioning anchor according to a time slot allocated to the respective positioning anchor.

[0338] In some embodiments, a method for transmitting a positioning signal in a positioning system is provided. In some embodiments, the positioning system may include a plurality of positioning anchors.

[0339] In some embodiments, the method may include using a plurality of positioning anchors to wirelessly transmit positioning signals that can be used by self-positioning devices within an area to determine location information. In some embodiments, the method may also include using at least one scheduling unit communicatively coupled to the plurality of positioning anchors to schedule transmission of the positioning signals according to a first transmission schedule. In some embodiments, the first transmission schedule may define a first temporal order for transmitting positioning signals for each of the plurality of positioning anchors.

[0340] In some embodiments, the method may further include using the at least one scheduling unit to determine when to change from the first transmission schedule to a second transmission schedule. In some embodiments, the second transmission schedule may define a second time sequence for transmitting positioning signals for each of the plurality of positioning anchors. The second transmission schedule may define a second transmitter (TX) or receiver (RX) mode for each of the plurality of positioning anchors. In some embodiments, the second time sequence may be different from the first time sequence.

[0341] In some embodiments, the method may further include: using the at least one scheduling unit to, in response to determining to change from the first transmission schedule to the second transmission schedule, schedule the transmission of the positioning signal according to the second transmission schedule. In some embodiments, such scheduling may change positioning performance within the area.

[0342] In some embodiments, the positioning signals may include ultra-wideband (UWB) positioning signals. In some embodiments, each positioning signal may include a preamble and a payload. In some embodiments, the payload of at least some of the UWB positioning signals may include commands. In some embodiments, the method may further include changing the at least one scheduling unit from a first transmission schedule to a second transmission schedule to optimize propagation of the commands to the self-positioning device and at least one of the plurality of anchors.

[0343] In some embodiments, each of the plurality of positioning anchors may include a clock. In some embodiments, the payload of at least some of the UWB positioning signals may include synchronization data. In some embodiments, the method may further include using each of the plurality of positioning anchors to receive synchronization data from a UWB positioning signal received from at least one other positioning anchor. In some embodiments, the method may further include changing the at least one scheduling unit from a first transmission schedule to a second transmission schedule to optimize for clock synchronization.

[0344] In some embodiments, each of the plurality of positioning anchors may include a synchronization unit. In some embodiments, the method may further include using each synchronization unit to calculate a correction for at least one of a clock offset and a clock rate of its corresponding clock based on the received synchronization data.

[0345] In some embodiments, the first transmission schedule and the second transmission schedule may provide at least one of increased precision, accuracy, and update rate in different portions of the area.

[0346] In some embodiments, the first transmission schedule and the second transmission schedule may each include a plurality of time slots. In some embodiments, the method may further include allocating a different number of time slots in the first transmission schedule and the second transmission schedule to at least one of the plurality of location anchors.

[0347] In some embodiments, the first transmission schedule and the second transmission schedule may each include multiple time slots. In some embodiments, the at least one scheduling unit may include multiple scheduling units. In some embodiments, each of the multiple scheduling units may be physically coupled to a corresponding one of the multiple positioning anchors. In some embodiments, the method may further include using each of the multiple scheduling units to schedule transmission of positioning signals for its respective positioning anchor according to the time slot assigned to its respective positioning anchor.

[0348] According to another aspect of the present disclosure, a system for determining a transmission schedule for a positioning system is provided. In some embodiments, the positioning system may include multiple positioning anchors configured to wirelessly transmit positioning signals. The multiple positioning anchors may be used to determine location information within an area.

[0349] In some embodiments, the system may include an input operable to receive: positions of a plurality of positioning anchors, at least one anchor attribute of the plurality of positioning anchors, and desired positioning performance within at least one sector within the area.

[0350] In some embodiments, the system may include at least one processor. The at least one processor may be configured to determine a transmission schedule for the plurality of anchors based on: (a) the positions of the plurality of positioning anchors, (b) at least one anchor attribute of the plurality of positioning anchors, and (c) expected positioning performance within at least one sector. In some embodiments, the plurality of positioning anchors may be configured to wirelessly transmit positioning signals according to the transmission schedule.

[0351] In some embodiments, the system may include an output operable to transmit a transmission schedule to a plurality of location anchors.

[0352] In some embodiments, the expected positioning performance within a first of the at least one partition may be higher than the expected positioning performance within a second of the at least one partition. In some embodiments, the determined transmission schedule may be determined to provide higher positioning performance within the first partition. In some embodiments, the at least one partition may cover the area.

[0353] In some embodiments, the at least one processor may be configured to determine a transmission schedule by predicting positioning performance within at least one partition based on the positions of a plurality of positioning anchors and at least one anchor attribute of the plurality of positioning anchors; and comparing the predicted positioning performance with the expected positioning performance within the at least one partition.

[0354] In some embodiments, the at least one anchor attribute may include a transmission power level. In some embodiments, the at least one processor may also be configured to determine a transmission power level for a transmission schedule. In some embodiments, the transmission schedule may indicate a power level at which each positioning anchor may be scheduled to transmit its positioning signal.

[0355] In some embodiments, the at least one anchor attribute may include a transmission center frequency. In some embodiments, the at least one processor may also be configured to determine the transmission center frequency for a transmission schedule. In some embodiments, the transmission schedule may indicate the transmission center frequency at which each positioning anchor may be scheduled to transmit its positioning signal.

[0356] In some embodiments, the at least one anchor attribute may include a transmission frequency bandwidth. In some embodiments, the at least one processor may also be configured to determine a transmission frequency bandwidth for a transmission schedule. In some embodiments, the transmission schedule may indicate a transmission frequency bandwidth at which each positioning anchor may be scheduled to transmit its positioning signal.

[0357] In some embodiments, the at least one anchor attribute may include a preamble. In some embodiments, the at least one processor may also be configured to determine a transmission schedule for the preamble. In some embodiments, the transmission schedule may indicate a preamble scheduled for use with each positioning signal.

[0358] In some embodiments, the at least one anchor attribute may include a preamble modulation scheme. In some embodiments, the at least one processor may also be configured to determine a preamble modulation scheme for a transmission schedule. In some embodiments, the transmission schedule may indicate a preamble modulation scheme scheduled for use with each positioning signal.

[0359] In some embodiments, the at least one anchor attribute may include a preamble length. In some embodiments, the at least one processor may also be configured to determine a preamble length for a transmission schedule. In some embodiments, the transmission schedule may indicate a preamble length scheduled for use with each positioning signal.

[0360] In some embodiments, the transmission schedule may include a plurality of time slots.In some embodiments, the at least one processor may be further configured to assign one or more positioning signals to each of the plurality of time slots.

[0361] In some embodiments, the at least one processor may be further configured to determine an amount of overlap between multiple time slots of the transmission schedule. In some embodiments, the amount of overlap between multiple time slots may be fixed. In some embodiments, the amount of overlap between multiple time slots may be variable. In some embodiments, the at least one processor may be configured to determine the transmission schedule by determining a temporal order in which multiple positioning anchors wirelessly transmit positioning signals.

[0362] In some embodiments, the at least one processor may be configured to determine the transmission schedule by determining a transmission rate at which the plurality of positioning anchors wirelessly transmit positioning signals.

[0363] In some embodiments, the transmission schedule may include a plurality of time slots. In some embodiments, the at least one processor may be further configured to allocate more time slots to location anchors having a higher transmission rate than to location anchors having a lower transmission rate.

[0364] In some embodiments, the at least one processor may be configured to determine the transmission schedule by using an optimization algorithm. In some embodiments, the at least one processor may be configured to determine the transmission schedule by minimizing a cost function.

[0365] In some embodiments, the input may be further operable to receive real-time location information of a self-locating device within the area. In some embodiments, the at least one processor may be further configured to determine an updated transmission schedule based on the real-time location information. In some embodiments, the real-time location information may be received from a memory of the system. In some embodiments, the desired location performance may include an airplane mode.

[0366] In some embodiments, a method for determining a transmission schedule for a positioning system is provided. In some embodiments, the positioning system may include a plurality of positioning anchors configured to wirelessly transmit positioning signals that can be used to determine position information within an area.

[0367] In some embodiments, the method may include receiving, using input, positions of a plurality of positioning anchors, at least one anchor attribute of the plurality of positioning anchors, and desired positioning performance within at least one sector within the area.

[0368] In some embodiments, the method may further include determining, using at least one processor, a transmission schedule for a plurality of anchors based on: (a) positions of the plurality of positioning anchors, (b) at least one anchor attribute of the plurality of positioning anchors, and (c) desired positioning performance within the at least one sector, wherein the plurality of positioning anchors are configured to wirelessly transmit the positioning signals according to the transmission schedule. In some embodiments, the method may further include using an output to transmit the transmission schedule to the plurality of positioning anchors.

[0369] In some embodiments, the method may further include using the at least one processor to predict positioning performance within the at least one partition based on the positions of the plurality of positioning anchors and the at least one anchor attribute of the plurality of positioning anchors. The method may further include using the at least one processor to compare the predicted positioning performance with the expected positioning performance within the at least one partition.

[0370] In some embodiments, the at least one anchor attribute may include a transmission power level. The method may also include determining, using at least one processor, a transmission power level for a transmission schedule. In some embodiments, the transmission schedule may indicate a power level at which each positioning anchor may be scheduled to transmit its positioning signal.

[0371] According to another aspect of the present disclosure, a positioning system may include a plurality of positioning anchors configured to wirelessly transmit positioning signals during time slots in a transmission schedule. In some embodiments, each positioning signal may include a payload. In some embodiments, the payload of each positioning signal may identify at least one positioning anchor of the plurality of positioning anchors configured to transmit positioning signals during at least one future time slot.

[0372] In some embodiments, a positioning system may include multiple positioning anchors configured to wirelessly transmit wireless signals during time slots in a transmission schedule. In some embodiments, each wireless signal may include a payload. In some embodiments, the payload of each wireless signal may identify a transmitter (TX) mode configuration or a receiver (RX) mode configuration of at least one of the multiple positioning anchors configured to transmit or receive positioning or wireless signals during at least one future time slot. In some embodiments, the payload may only identify the configuration for the TX mode, and the anchor may determine its RX mode.

[0373] In some embodiments, the positioning system may include a self-positioning device. In some embodiments, the self-positioning device may include a receiver. The self-positioning device may be configured to receive at least some positioning signals and extract the payload of the received positioning signals. The self-positioning device may also be configured to determine, based on the extracted payload of the received positioning signals, which positioning signal to receive for determining the positioning information of the self-positioning device. The self-positioning device may be configured to configure the receiver based on the determined positioning signal. The self-positioning device may also be configured to receive the determined positioning signal using the configured receiver and determine the positioning information of the self-positioning device based on the received determined positioning signal.

[0374] In some embodiments, each positioning signal may include a header portion and a payload portion. In some embodiments, the header portion may be a preamble. In some embodiments, the positioning signals may include a first subgroup and a second subgroup. In some embodiments, the first subgroup and the second subgroup may include at least one different transmission characteristic. In some embodiments, the at least one different transmission characteristic may include at least one of a transmission center frequency, a transmission frequency bandwidth, a preamble, and a preamble modulation scheme. In some embodiments, the positioning signals from the first subgroup and the positioning signals from the second subgroup may both be scheduled for transmission during the same time slot of a transmission schedule.

[0375] In some embodiments, the self-positioning device may be configured to determine which positioning signals to receive based on state information. In some embodiments, the state information may include the current location of the self-positioning device. In some embodiments, the state information may include variance information associated with a positioning estimator of the self-positioning device.

[0376] In some embodiments, the self-positioning device may be configured to determine which positioning signals to receive to minimize a variance associated with a positioning estimator.

[0377] In some embodiments, the payload for each positioning signal may identify two positioning anchors from a plurality of positioning anchors that are configured to transmit positioning signals during the same future time slot. In some embodiments, the payload for each positioning signal may identify at least one positioning anchor from a plurality of positioning anchors that is configured to transmit positioning signals during each of at least two future time slots.

[0378] In some embodiments, a positioning method is provided. The method may include using a plurality of positioning anchors to wirelessly transmit positioning signals during time slots in a transmission schedule. In some embodiments, each positioning signal may include a payload. In some embodiments, the payload for each positioning signal may identify at least one positioning anchor from the plurality of positioning anchors configured to transmit the positioning signal during at least one future time slot.

[0379] The method may include using a self-positioning device to receive at least some positioning signals, extracting payloads of the received positioning signals, and determining which positioning signals to receive for determining positioning information for the self-positioning device based on the extracted payloads of the received positioning signals. In some embodiments, the method may include configuring a receiver of the self-positioning device based on the determined positioning signals. In some embodiments, the method may also include using the configured receiver to receive the determined positioning signals and determine positioning information.

[0380] In some embodiments, the positioning signals may include a first subset and a second subset, wherein the first subset and the second subset include at least one different transmission characteristic.

[0381] In some embodiments, the at least one different transmission characteristic includes at least one of a transmission center frequency, a transmission frequency bandwidth, a preamble, and a preamble modulation scheme. In some embodiments, the positioning signal from the first subgroup and the positioning signal from the second subgroup can both be scheduled for transmission during the same time slot of the transmission schedule.

[0382] In some embodiments, the method may further include using the self-positioning device to determine which positioning signals to receive based on state information. In some embodiments, the state information may include a current location of the self-positioning device. In some embodiments, the state information may include variance information associated with a positioning estimator of the self-positioning device.

[0383] In some embodiments, the method may further include using the self-positioning device to determine which positioning signals to receive to minimize a variance associated with the positioning estimator.

[0384] In some embodiments, the payload of each positioning signal may identify two positioning anchors from the plurality of positioning anchors that are configured to transmit positioning signals during the same future time slot. In some embodiments, the payload of each positioning signal may identify at least one positioning anchor from the plurality of positioning anchors that is configured to transmit positioning signals during each of at least two future time slots.

[0385] According to another aspect of the present disclosure, a positioning system is provided, comprising a first positioning network configured to wirelessly transmit a first positioning signal using a first set of time synchronization anchors. In some embodiments, the first positioning signal can be used to determine position information within a first area.

[0386] In some embodiments, the positioning system may further include a second positioning network configured to wirelessly transmit a second positioning signal using a second set of time synchronization anchors. In some embodiments, the second positioning signal may be used to determine position information within a second area.

[0387] In some embodiments, the positioning system may further include a bridging anchor. In some embodiments, the bridging anchor may be configured to receive first time synchronization information associated with a first set of time synchronization anchors. The bridging anchor may be configured to receive second time synchronization information associated with a second set of time synchronization anchors, and to transmit time synchronization information associated with the first time synchronization information to a second positioning network. In some embodiments, the time synchronization information may include at least one of a clock offset and a clock rate of the first positioning network.

[0388] In some embodiments, the second positioning network may be configured to adjust at least one of a clock offset and a clock rate based on the received time synchronization information so as to synchronize the second positioning network with the first positioning network.

[0389] In some embodiments, the bridging anchor may be configured to wirelessly transmit the time synchronization information. In some embodiments, at least one anchor of the second positioning network may be configured to wirelessly receive the time synchronization information.

[0390] In some embodiments, the bridging anchor may be further configured to transmit time synchronization information related to the second time synchronization information to the first positioning network.

[0391] In some embodiments, the bridging anchor may be configured to wirelessly transmit time synchronization information to a self-positioning device of the first positioning network to enable the self-positioning device to determine its position using the first positioning network and the second positioning network.

[0392] In some embodiments, the self-positioning device can be configured to switch between receiving positioning signals from a first positioning network and receiving positioning signals from a second positioning network based on the received time synchronization information. In some embodiments, the switching can be achieved by reconfiguring a receiver of the self-positioning device. In some embodiments, the signal transmitted by the bridging anchor can include a payload representing the receiver configuration of at least one of the two positioning networks. In some embodiments, the self-positioning device can reconfigure its receiver based on the payload received from the bridging anchor.

[0393] In some embodiments, the bridging anchor may further be configured to wirelessly transmit one or more second positioning signals. In some embodiments, one or more of the second positioning signals may each include a preamble and a payload. In some embodiments, the payload of the one or more second positioning signals may include time synchronization information.

[0394] In some embodiments, the positioning system of the claims may further include a self-positioning device. In some embodiments, the self-positioning device may be configured to receive a second positioning signal and determine the position information based on the received second positioning signal. In some embodiments, the self-positioning device may be configured to configure its receiver to receive a first positioning signal and determine the position information based on the received first positioning signal.

[0395] In some embodiments, the self-positioning device may further be configured to receive time synchronization information from the bridging anchor. In some embodiments, determining the position information based on the received first positioning signal may further be performed in dependence on the time synchronization information from the bridging anchor.

[0396] In some embodiments, the self-positioning device may be configured to receive one or more first positioning signals from a first positioning network, one or more second positioning signals from a bridging anchor, and one or more second positioning signals from a second positioning network. In some embodiments, the self-positioning device may also be configured to determine location information based on the one or more first positioning signals received from the first positioning network, the one or more second positioning signals received from the second positioning network, and time synchronization information received from the bridging anchor.

[0397] In some embodiments, the bridging anchor may be configured to alternately receive positioning signals from the first positioning network and the second positioning network. In some embodiments, the first area and the second area at least partially overlap.

[0398] In some embodiments, the bridging anchor may be configured to determine relative time information based on the received first time synchronization information and the received second time synchronization information, and wherein the time synchronization information transmitted by the bridging anchor includes the relative time information.

[0399] In some embodiments, the positioning system may include a first positioning network configured to transmit a first positioning signal using a first set of time synchronization anchors. In some embodiments, the first positioning signal may be used to determine location information within a first area.

[0400] In some embodiments, the positioning system may include a second positioning network configured to transmit a second positioning signal using a second set of time synchronization anchors. In some embodiments, the second positioning signal may be used to determine position information within a second area. In some embodiments, the positioning system may include a bridging anchor.

[0401] In some embodiments, the bridging anchor may be configured to receive first time synchronization information associated with a first set of time synchronization anchors, and to receive second time synchronization information associated with a second set of time synchronization anchors. In some embodiments, the bridging anchor may be configured to transmit a first positioning signal as part of a first positioning network based on the received first time synchronization information in a first operating mode; and to transmit a second positioning signal as part of a second positioning network based on the received second time synchronization information in a second operating mode.

[0402] In some embodiments, the bridging anchor may be configured to switch between the first operating mode and the second operating mode based on desired positioning performance of at least one of the first positioning network and the second positioning network.

[0403] In some embodiments, a positioning method is provided. In some embodiments, the positioning method may include using a first positioning network to wirelessly transmit a first positioning signal using a first set of time synchronization anchors. The first positioning signal may be position information within a first area that can be used to determine the position.

[0404] In some embodiments, the positioning method may include using a second positioning network to wirelessly transmit a second positioning signal using a second set of time synchronization anchors. The second positioning signal may be usable to determine position information within the second area.

[0405] In some embodiments, the positioning method may further include using a bridging anchor to receive first time synchronization information associated with a first set of time synchronization anchors and receiving second time synchronization information associated with a second set of time synchronization anchors. The positioning method may further include using the bridging anchor to transmit time synchronization information associated with the first time synchronization information to a second positioning network.

[0406] In some embodiments, the positioning method may further include using the bridging anchor to wirelessly transmit time synchronization information to the self-positioning device of the first positioning network, so that the self-positioning device can determine its position using the first positioning network and the second positioning network.

[0407] In some embodiments, another positioning method is provided. In some embodiments, the positioning method may include using a first positioning network to transmit a first positioning signal using a first set of time synchronization anchors. The first positioning signal may be position information within a first area that can be used to determine the position.

[0408] In some embodiments, the positioning method may further include using a second positioning network to transmit a second positioning signal using a second set of time synchronization anchors. The second positioning signal may be position information within the second area that can be used to determine.

[0409] In some embodiments, the positioning method may further include using the bridging anchor to receive first time synchronization information related to the first set of time synchronization anchors and to receive second time synchronization information related to the second set of time synchronization anchors.

[0410] In some embodiments, the positioning method may further include using the bridging anchor to transmit a first positioning signal as part of a first positioning network based on the received first time synchronization information in a first operating mode, and to transmit a second positioning signal as part of a second positioning network based on the received second time synchronization information in a second operating mode.

[0411] According to another aspect of the present disclosure, a positioning system is provided, the positioning system comprising a first anchor configured to transmit a first positioning signal capable of time stamping. In some embodiments, the first positioning signal capable of time stamping comprises a preamble followed by a payload.

[0412] The positioning system may further include a second anchor configured to transmit a second time-tagged positioning signal. In some embodiments, the second time-tagged positioning signal may include a preamble followed by a payload. In some embodiments, the transmission of the second time-tagged positioning signal may partially overlap with the transmission of the first time-tagged positioning signal such that the second time-tagged positioning signal does not overlap with the preamble of the first time-tagged positioning signal. In some embodiments, the first time-tagged positioning signal and the second time-tagged positioning signal may be received within a common area.

[0413] In some embodiments, transmission of the second positioning signal capable of time stamping can begin before transmission of the first positioning signal capable of time stamping ends. In some embodiments, transmission of the second positioning signal capable of time stamping can begin after transmission of the preamble of the first positioning signal capable of time stamping ends. In some embodiments, the preamble of the second positioning signal capable of time stamping can overlap with the payload of the first positioning signal capable of time stamping.

[0414] In some embodiments, the preamble of the first positioning signal capable of time stamping may include a first coded preamble. In some embodiments, the preamble of the second positioning signal capable of time stamping may include a second coded preamble of the same encoding.

[0415] In some embodiments, the positioning system may include a self-positioning device. In some embodiments, the self-positioning device may be configured to receive the entire first time-tagged positioning signal or the entire second time-tagged positioning signal, rather than the entire first time-tagged positioning signal and the entire second time-tagged positioning signal. In some embodiments, the self-positioning device may be configured to receive a preamble of the first time-tagged positioning signal and the entire second time-tagged positioning signal.

[0416] In some embodiments, the first positioning signal capable of time-stamping may further include a start of frame delimiter (SFD) between the preamble and the payload. In some embodiments, the second positioning signal capable of time-stamping may not overlap with the SFD of the first positioning signal capable of time-stamping. In some embodiments, the self-positioning device may be configured to receive the preamble and SFD of the first positioning signal capable of time-stamping and the entire second positioning signal capable of time-stamping.

[0417] In some embodiments, the self-positioning device may be further configured to determine a time stamp corresponding to the reception of the preamble or SFD of the first positioning signal; and determine the position information based on the first positioning signal capable of time stamping and the known transmission time of the time stamp.

[0418] In some embodiments, the payload of the first time-stamped positioning signal may include a first payload and a second payload. In some embodiments, the second time-stamped positioning signal may overlap with the second payload but not with the first payload of the first time-stamped positioning signal. In some embodiments, the self-positioning device may be configured to receive the first payload of the first time-stamped positioning signal and the entire second time-stamped positioning signal.

[0419] In some embodiments, the first anchor may be configured to transmit a first positioning signal capable of time stamping using a transmission center frequency and a transmission frequency bandwidth. In some embodiments, the second anchor may be configured to transmit a second positioning signal capable of time stamping using a transmission center frequency and a transmission frequency bandwidth.

[0420] In some embodiments, the first anchor can be configured to transmit a plurality of first positioning signals capable of time-stamping. In some embodiments, the second anchor can be configured to transmit a plurality of second positioning signals capable of time-stamping. In some embodiments, each of the plurality of second positioning signals capable of time-stamping can partially overlap with a corresponding one of the plurality of first positioning signals capable of time-stamping.

[0421] In some embodiments, the positioning system may further include four or more anchors. In some embodiments, the four or more anchors may include a first anchor and a second anchor. In some embodiments, the four or more anchors may be configured to transmit the time-tagged positioning signal according to a transmission schedule that partially overlaps with the transmission of the time-tagged positioning signal, thereby enabling the time-tagged positioning system to transmit more time-tagged signals per time unit than would be the case if the time-tagged positioning signals did not overlap.

[0422] In some embodiments, the payload of each of the first time-tagged capable positioning signal and the second time-tagged capable positioning signal identifies when the anchor may be configured to transmit the positioning signal during a future time slot.

[0423] In some embodiments, the self-positioning device may be configured to receive an identification of when an anchor may be configured to transmit a positioning signal during a future time slot, and select which time-stamp signal to receive overall based on the received identification.

[0424] In some embodiments, a method for positioning is provided. In some embodiments, the method may include transmitting a first positioning signal capable of time stamping using a first anchor. In some embodiments, the first positioning signal capable of time stamping may include a preamble followed by a payload.

[0425] In some embodiments, the method may further include transmitting a second time-tagged positioning signal using the second anchor. In some embodiments, the second time-tagged positioning signal may include a preamble followed by a payload. In some embodiments, the transmission of the second time-tagged positioning signal may partially overlap with the transmission of the first time-tagged positioning signal such that the second time-tagged positioning signal does not overlap with the preamble of the first time-tagged positioning signal. In some embodiments, the first time-tagged positioning signal and the second time-tagged positioning signal may be received within a common area.

[0426] In some embodiments, the first time-stamping capable positioning signal may include a first ultra-wideband (UWB) signal, and the second time-stamping capable positioning signal may include a second UWB signal.

[0427] In some embodiments, the first positioning signal capable of time-stamping may further include a start of frame delimiter (SFD) between the preamble and the payload. In some embodiments, the second positioning signal capable of time-stamping may not overlap with the SFD of the first positioning signal capable of time-stamping. In some embodiments, the method may further include using a self-positioning device to receive the preamble and SFD of the first positioning signal capable of time-stamping and the entire second positioning signal capable of time-stamping.

[0428] In some embodiments, the method may further include using the self-positioning device to determine a time stamp corresponding to receipt of a preamble or SFD of the first positioning signal; and determining the position information based on the known transmission time of the first positioning signal capable of time stamping and the time stamp.

[0429] In some embodiments, the payload of the first positioning signal capable of time stamping may include a first payload and a second payload, and wherein the second positioning signal capable of time stamping may overlap with the second payload but does not overlap with the first payload of the first positioning signal capable of time stamping. In some embodiments, the method may further include using a self-positioning device to receive the first payload of the first positioning signal capable of time stamping and the entire second positioning signal capable of time stamping.

[0430] According to another aspect of the present disclosure, a method for operating a positioning system is provided. In some embodiments, the positioning system may include a plurality of positioning anchors. In some embodiments, the method may include assigning a first subset of the plurality of positioning anchors to a first subnet. The method may also include operating a first subnet of the first subset of positioning anchors to transmit a first positioning signal according to a first transmission schedule. In some embodiments, the first positioning signal may be used by a self-positioning device to determine location information within a first geographic area;

[0431] The method may further include adjusting the assignment of the plurality of location anchors to the first subnet such that a second subset of the plurality of location anchors may be assigned to the first subnet. In some embodiments, at least one location anchor of the first subset is not included in the second subset, and at least one location anchor of the second subset is not included in the first subset.

[0432] The method may also include operating the first subnet of the second subset of positioning anchors to transmit a second positioning signal according to a second transmission schedule. In some embodiments, the second positioning signal can be used by the self-positioning device to determine position information within a second geographic area. In some embodiments, the first geographic area and the third geographic area do not overlap.

[0433] In some embodiments, the first positioning signal may include a first ultra-wideband (UWB) signal, and the second positioning signal may include a second UWB signal.

[0434] In some embodiments, the method may further include assigning a third subset of the plurality of location anchors to the second subnet, and operating the second subnet of the third subset of location anchors to transmit a third positioning signal according to a third transmission schedule. In some embodiments, the third positioning signal may be used by the self-locating device to determine location information within a third geographic area.

[0435] In some embodiments, the method may further include operating the first subnet and the second subnet concurrently.In some embodiments, the third subset of the plurality of location anchors may not include any location anchor of the first subset of the plurality of location anchors.

[0436] In some embodiments, the method may further include simultaneously operating a first subnet and a second subnet of a first subset of the plurality of positioning anchors. In some embodiments, a third subset of the plurality of positioning anchors may include at least one positioning anchor from the first subset of the plurality of positioning anchors. In some embodiments, the first positioning signal and the third positioning signal may be transmitted using at least one different transmission characteristic. In some embodiments, the at least one different transmission characteristic may include at least one of a transmission center frequency, a transmission frequency bandwidth, a preamble, and a preamble modulation scheme.

[0437] In some embodiments, the method may further include simultaneously operating a first subnet and a second subnet of the first subset of the plurality of location anchors. In some embodiments, at least one of the anchors of the first subnet may be operated using a lower transmit power to reduce the size of the first geographic area such that the first geographic area and the second geographic area do not overlap.

[0438] In some embodiments, the first subnet and the second subnet may use the same transmission characteristics to transmit the first positioning signal and the second positioning signal. In some embodiments, the first positioning signal and the second positioning signal may overlap in time.

[0439] In some embodiments, the method may further include adjusting the assignment of the plurality of location anchors to the second subnet such that a fourth subset of the plurality of location anchors may be assigned to the second subnet. In some embodiments, at least one location anchor of the third subset is not included in the fourth subset and at least one location anchor of the fourth subset is not included in the third subset.

[0440] In some embodiments, the method may further include adjusting the assignment of the plurality of location anchors to the first subnet to dynamically change the geographic area served by the first subnet. In some embodiments, the assignment of the plurality of location anchors to the first subnet may be adjusted based on known motion of at least one self-locating device served by the first subnet. In some embodiments, the motion may be a flight pattern.

[0441] In some embodiments, the method may further include receiving a known location of at least one self-locating device. In some embodiments, the location may be received from a memory of the self-locating device. In some embodiments, the received known location retrieved from the memory is an expected location of the self-locating device. In some embodiments, the expected location is predicted based on a time elapsed since the start of trajectory execution. In some embodiments, use of the first subnet in the positioning system may improve positioning performance within the first geographic area.

[0442] In some embodiments, a positioning system is provided. The positioning system may include a plurality of positioning anchors. In some embodiments, the positioning system may be configured to assign a first subset of the plurality of positioning anchors to a first subnet. The positioning system may be configured to operate a first subnet of the first subset of positioning anchors to transmit a first positioning signal according to a first transmission schedule. In some embodiments, the first positioning signal may be used by a self-positioning device to determine location information within a first geographic area.

[0443] The positioning system may also be configured to adjust the assignment of the plurality of positioning anchors to the first subnet such that a second subset of the plurality of positioning anchors may be assigned to the first subnet. In some embodiments, at least one positioning anchor of the first subset is not included in the second subset and at least one positioning anchor of the second subset is not included in the first subset.

[0444] The positioning system may also be configured to operate the first subnet of the second subset of positioning anchors to transmit a second positioning signal according to a second transmission schedule. In some embodiments, the second positioning signal may be used by the self-positioning device to determine location information within a second geographic area.

[0445] In some embodiments, the first positioning signal may include a first ultra-wideband (UWB) signal, and the second positioning signal may include a second UWB signal.

[0446] In some embodiments, the positioning system can be further configured to assign a third subset of the plurality of positioning anchors to the second subnet; and operate the second subnet of the third subset of positioning anchors to transmit a third positioning signal according to a third transmission schedule. In some embodiments, the third positioning signal can be used by the self-positioning device to determine location information within a third geographic area.

[0447] In some embodiments, another positioning system is provided. In some embodiments, the positioning system may include multiple positioning anchors. In some embodiments, the multiple positioning anchors may include at least a first positioning anchor, a second positioning anchor, and a third positioning anchor.

[0448] In some embodiments, a first subset of location anchors can be configured to transmit a first positioning signal during a first time period according to a first transmission schedule. In some embodiments, the first positioning signal can be used by a self-positioning device to determine location information within a first geographic area. In some embodiments, the first subset of anchor locations can include a first location anchor and a second location anchor. In some embodiments, a third location anchor can be configured not to transmit during the first time period.

[0449] In some embodiments, the second subset of location anchors can be configured to transmit a second positioning signal during a second subsequent time period according to a second transmission schedule. In some embodiments, the second positioning signal can be used by the self-positioning device to determine location information within a second geographic area. In some embodiments, the second subset of location anchors can include the first location anchor and the third location anchor. In some embodiments, the second location anchor can be configured not to transmit during the second time period.

[0450] According to another aspect of the present disclosure, a method for operating a positioning system is provided. In some embodiments, the positioning system may include multiple positioning anchors. In some embodiments, the method may include using the multiple positioning anchors to transmit a first time-stamped positioning signal according to a first transmission schedule. In some embodiments, the first time-stamped positioning signal may include a first set of transmission characteristics, and wherein the first time-stamped positioning signal may be used by a self-positioning device to determine position information within a first geographic area.

[0451] In some embodiments, the method may further include using the plurality of positioning anchors to transmit a second time-tagged positioning signal according to a second transmission schedule. In some embodiments, the second time-tagged positioning signal may include a second set of transmission characteristics. In some embodiments, the second time-tagged positioning signal may be used by the self-positioning device to determine position information within a second geographic area.

[0452] In some embodiments, the first geographic area and the second geographic area may at least partially overlap. In some embodiments, at least some of the first and second time-stamped positioning signals may be transmitted such that they overlap in time. In some embodiments, at least one type of transmission characteristic may differ from the transmission characteristics in the first and second transmission characteristic sets to reduce interference between at least some of the overlapping first and second time-stamped positioning signals.

[0453] In some embodiments, the first time-stamping capable positioning signal may include a first ultra-wideband (UWB) signal, and the second time-stamping capable positioning signal may include a second UWB signal.

[0454] In some embodiments, the at least one type of transmission characteristic may include at least one of a transmission center frequency, a transmission frequency bandwidth, a preamble code, and a preamble modulation scheme.

[0455] In some embodiments, one of the plurality of positioning anchors may include a first antenna and a second antenna, and the one of the plurality of positioning anchors may be configured to transmit one of the first time-tagged positioning signals using the first antenna and to transmit one of the second time-tagged positioning signals using the second antenna.

[0456] In some embodiments, a positioning anchor may be configured to transmit a first time-tagged positioning signal and a second time-tagged positioning signal such that they overlap in time.

[0457] In some embodiments, the self-positioning device may include at least one reception setting. In some embodiments, the method may further include configuring the at least one reception setting of the self-positioning device to select which of the first positioning signal capable of time-stamping and the second positioning signal capable of time-stamping is received.

[0458] In some embodiments, the method may further include using the self-positioning device to determine whether to receive one of the first positioning signals capable of time stamping or one of the second positioning signals capable of time stamping based on information. In some embodiments, the information may include configuration information received as part of a previously received positioning signal capable of time stamping. In some embodiments, the information may include information stored on a memory of the self-positioning device. In some embodiments, the information may include one of an internal metric of the self-positioning device and an internal state of the self-positioning device.

[0459] In some embodiments, the method may further include using one of the plurality of location anchors to receive at least one of a first time-stampable location signal and a second time-stampable location signal transmitted by at least one other of the plurality of location anchors. In some embodiments, the method may further include using one of the location anchors to determine whether to receive one of the first time-stampable location signals or one of the second time-stampable location signals based on information. In some embodiments, the information may include configuration information received as part of a previously received time-stampable location signal. In some embodiments, the information may include information stored in a memory of one of the location anchors.

[0460] In some embodiments, the first set of transmission characteristics and the second set of transmission characteristics may include the same center frequency and transmission frequency bandwidth.

[0461] In some embodiments, a positioning system is provided. In some embodiments, the positioning system may include multiple positioning anchors. In some embodiments, the multiple positioning anchors may be configured to transmit a first time-stamped positioning signal according to a first transmission schedule. In some embodiments, the first time-stamped positioning signal may include a first set of transmission characteristics. In some embodiments, the first time-stamped positioning signal may be used by a self-positioning device to determine position information within a first geographic area.

[0462] In some embodiments, the plurality of location anchors may be configured to transmit a second time-stamped positioning signal according to a second transmission schedule. In some embodiments, the second time-stamped positioning signal may include a second set of transmission characteristics. In some embodiments, the second time-stamped positioning signal may be used by the self-positioning device to determine position information within a second geographic area.

[0463] In some embodiments, the first geographic area and the second geographic area may at least partially overlap. In some embodiments, at least some of the first and second time-stamped positioning signals may be transmitted such that they overlap in time. In some embodiments, at least one type of transmission characteristic may differ from the transmission characteristics in the first and second transmission characteristic sets to reduce interference between at least some of the overlapping first and second time-stamped positioning signals.

[0464] In some embodiments, the first time-stamping capable positioning signal may include a first ultra-wideband (UWB) signal, and the second time-stamping capable positioning signal may include a second UWB signal.

[0465] In some embodiments, the plurality of positioning anchors may further include a first set of three RF anchors and a second set of three RF anchors. Each of the RF anchors may be configured to transmit a RF signal. In some embodiments, each of the RF anchors may include an anchor antenna, an anchor clock interface operable to receive an anchor clock signal, and analog transmission electronics.

[0466] In some embodiments, each of the RF anchors may include digital transmission electronics operatively coupled to an anchor clock interface and analog transmission electronics and operable to transmit RF signals referenced to the anchor clock signal at scheduled transmission times.

[0467] In some embodiments, the system may further include a self-positioning device. In some embodiments, the self-positioning device may be configured to receive radio frequency signals. In some embodiments, the self-positioning device may include a device antenna; a device clock interface configured to receive a device clock signal; and device analog receiving electronics.

[0468] In some embodiments, the system may further include device digital receive electronics operably coupled to the device clock interface and the device analog receive electronics and configured to time-stamp received RF signals with reference to the device clock signal. In some embodiments, the first set of RF anchors and the second set of RF anchors may operate in geographically adjacent cells having an overlapping area. In some embodiments, the self-positioning device may be configured to receive RF signals from either the first set of RF anchors or the second set of RF anchors when positioned in the overlapping area. In some embodiments, the plurality of positioning anchors may be configured to utilize at least one of signal spacing in time, signal spacing in space, or signal spacing in frequency to mitigate signal interference between the first set of RF anchors and the second set of RF anchors.

[0469] In some embodiments, the at least one type of transmission characteristic may include at least one of a transmission center frequency, a transmission frequency bandwidth, a preamble code, and a preamble modulation scheme.

[0470] In some embodiments, one of the plurality of location anchors may be further configured to receive at least one of a first time-stampable location signal and a second time-stampable location signal transmitted by at least one other of the plurality of location anchors.

[0471] According to another aspect of the present disclosure, a self-positioning device for determining a position of a vehicle is provided. In some embodiments, the self-positioning device may include a first subsystem and a second subsystem.

[0472] In some embodiments, the first subsystem may include a first antenna operable to receive a first RF signal, and first analog receive electronics configured to amplify the first RF signal. The first subsystem may also include first digital receive electronics configured to time-stamp the amplified first RF signal with reference to a clock signal, and a first positioning unit configured to calculate a first estimate of the position of the self-positioning device in a coordinate system based on the time-stamp of the amplified first RF signal.

[0473] In some embodiments, the second subsystem may include a second antenna operable to receive a second RF signal, and second analog receive electronics configured to amplify the second RF signal. The second subsystem may also include second digital receive electronics configured to time-stamp the amplified second RF signal with reference to a clock signal; and a second positioning unit configured to calculate a second estimate of the position of the self-positioning device in the coordinate system based on the time-stamp of the amplified second RF signal.

[0474] In some embodiments, each of the first subsystem and the second subsystem may be configured to be selectively used to control the vehicle independent of the other subsystem.

[0475] In some embodiments, the first subsystem and the second subsystem can be fully redundant. For example, in some embodiments, the first subsystem can further include a first clock. In some embodiments, the first digital receiving electronics can be configured to time-stamp the amplified first RF signal with reference to a first clock signal generated by the first clock. In some embodiments, the second subsystem can further include a second clock. In some embodiments, the second digital receiving electronics can be configured to time-stamp the amplified second RF signal with reference to a second clock signal generated by the second clock.

[0476] In some embodiments, the first subsystem may further include a first synchronization unit configured to calculate a clock correction for the first clock. In some embodiments, the second subsystem may further include a second synchronization unit configured to calculate a clock correction for the second clock.

[0477] In some embodiments, the first subsystem may further include a first sensor for sensing at least one of the position, orientation, or velocity of the self-positioning device relative to an external reference frame. In some embodiments, the first positioning unit may be configured to further calculate a first estimate of the position of the self-positioning device based on a first signal generated by the first sensor. In some embodiments, the second subsystem may further include a second sensor for sensing at least one of the position, orientation, or velocity of the self-positioning device relative to an external reference frame. In some embodiments, the second positioning unit may be configured to further calculate a second estimate of the position of the self-positioning device based on a second signal generated by the second sensor. In some embodiments, the first sensor may be a first global property sensor; and the second sensor may be a second global property sensor.

[0478] In some embodiments, the first subsystem may further include a first compensation unit. In some embodiments, the first positioning unit may be configured to calculate a first estimate of the position of the self-positioning device based on data provided by the first compensation unit. In some embodiments, the second subsystem may further include a second compensation unit. In some embodiments, the second positioning unit may be configured to calculate a second estimate of the position of the self-positioning device based on data provided by the second compensation unit.

[0479] In some embodiments, the first subsystem and the second subsystem may be partially redundant. For example, in some embodiments, the self-positioning device may include a clock. The first digital receiving electronics may be configured to time-stamp the amplified first RF signal with reference to a first clock signal generated by the clock. The second digital receiving electronics may also be configured to time-stamp the amplified second RF signal with reference to the first clock signal generated by the clock. In some embodiments, the self-positioning device may include a synchronization unit. In some embodiments, the synchronization unit may be configured to calculate a clock correction for the clock.

[0480] In some embodiments, the self-positioning device may further include a sensor for sensing at least one of a position, orientation, or velocity of the self-positioning device relative to an external reference frame. In some embodiments, the first positioning unit may be configured to further calculate a first estimate of the position of the self-positioning device based on a first signal generated by the sensor. In some embodiments, the second positioning unit may be configured to calculate a second estimate of the position of the self-positioning device based on the first signal generated by the sensor. In some embodiments, the sensor is a global property sensor.

[0481] In some embodiments, the self-positioning device may further include a compensation unit. In some embodiments, the first positioning unit may be configured to calculate a first estimate of the position of the self-positioning device further based on data provided by the compensation unit. In some embodiments, the second positioning unit may be configured to calculate a second estimate of the position of the self-positioning device further based on data provided by the compensation unit.

[0482] In some embodiments, a self-positioning device for use in a positioning network is provided. In some embodiments, the positioning network may include a plurality of anchors configured to transmit radio frequency signals. In some embodiments, the self-positioning device may include an antenna operable to receive radio frequency signals from the positioning network. In some embodiments, the self-positioning device may include analog receiving electronics configured to amplify radio frequency signals received by the antenna.

[0483] In some embodiments, the self-positioning device may include digital receiving electronics configured to time-stamp the amplified radio frequency signal with reference to a first clock signal to generate a plurality of time stamps. In some embodiments, the self-positioning device may include a positioning unit. In some embodiments, the positioning unit may be configured to calculate an estimate of the position of the self-positioning device in a coordinate system based on the time stamps and to determine receipt of a selected future radio frequency signal from among the at least two future radio frequency signals.

[0484] In some embodiments, the positioning unit may be configured to configure at least one of the antenna, the analog receiving electronics, and the digital receiving electronics to receive the selected radio frequency signal; and calculate an updated estimate of the position of the self-positioning device in the coordinate system based on the received selected radio frequency signal.

[0485] In some embodiments, the self-positioning device may further include digital transmission electronics and analog transmission electronics that may be configured to transmit the position of the self-positioning device to at least one of the plurality of anchors.

[0486] In some embodiments, the received radio frequency signals may each include a payload. In some embodiments, the digital receiving electronics may be configured to extract the payload. In some embodiments, the payload may identify at least one of a plurality of anchors that may be configured to transmit a positioning signal during at least one future time slot.

[0487] In some embodiments, the positioning unit may be configured to determine to receive the selected future radio frequency signal based on a position of an anchor that may be configured to transmit the selected future radio frequency signal and a variance associated with the calculated estimate of the position of the self-positioning device.

[0488] In some embodiments, the at least two future RF signals may partially overlap in time. In some embodiments, the positioning unit may be configured to determine whether to receive the entire selected future RF signal or only a portion of another of the at least two future RF signals. In some embodiments, the positioning unit may be configured to receive one of the following: (i) a portion of the first of the at least two future RF signals and the entire second of the at least two future RF signals, or (ii) the entire first of the at least two future RF signals but not the second of the at least two future RF signals. In some embodiments, the at least two future RF signals may use different preambles. In some embodiments, the at least two future RF signals may be transmitted by different positioning networks.

[0489] In some embodiments, the positioning unit may be further configured to calculate an estimate of the position of the self-positioning device in the coordinate system based on a known position of an anchor configured to transmit a radio frequency received by the antenna.

[0490] In some embodiments, a method for determining a position of a vehicle using a self-positioning device is provided. In some embodiments, the self-positioning device may include a first subsystem and a second subsystem.

[0491] In some embodiments, the method may include receiving the first radio frequency signal using a first antenna of the first subsystem.The method may further include amplifying the first radio frequency signal using first analog receive electronics of the first subsystem.

[0492] The method may further include time-stamping the amplified first radio frequency signal using a first digital receive electronics reference clock signal of the first subsystem.The method may further include calculating a first estimate of the position of the self-positioning device in the coordinate system using a first positioning unit of the first subsystem.

[0493] In some embodiments, the method may include receiving a second radio frequency signal using a second antenna of the second subsystem.The method may further include amplifying the second radio frequency signal using second analog receive electronics of the second subsystem.

[0494] The method may further include time-stamping the amplified second RF signal using a second digital receive electronics reference clock signal of the second subsystem.The method may further include calculating a second estimate of the position of the self-positioning device in the coordinate system using a second positioning unit of the second subsystem.

[0495] The method may further include controlling the vehicle using one of the first subsystem and the second subsystem independently of the other subsystem.

[0496] In some embodiments, a method for positioning a self-positioning device in a positioning network is provided. In some embodiments, the positioning network may include a plurality of anchors configured to transmit radio frequency signals. In some embodiments, the method may include using an antenna to receive the radio frequency signal from the positioning network. The method may also include amplifying the radio frequency signal received by the antenna using analog receiving electronics. The method may also include time-stamping the amplified radio frequency signal with reference to a first clock signal using digital receiving electronics to generate a plurality of time stamps.

[0497] The method may also include using the positioning unit to calculate an estimate of the position of the self-positioning device in the coordinate system based on the time stamp. The method may also include using the positioning unit to determine receiving a selected future radio frequency signal from at least two future radio frequency signals. The method may also include using the positioning unit to configure analog receiving electronics and using digital receiving electronics to receive the selected radio frequency signal. The method may further include using the positioning unit to calculate an updated estimate of the position of the self-positioning device in the coordinate system based on the received selected radio frequency signal.

[0498] Although certain aspects of the present disclosure have been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined in the following claims. For example, specific aspects of the present disclosure applied to time-stamped signals may be equally applicable to UWB signals, and vice versa. As another example, specific aspects of the present disclosure applied to time-stamped signals may be equally applicable to non-time-stamped positioning signals.

[0499] It will also be understood that the transceivers, devices, and components of the present disclosure may include hardware components or a combination of hardware and software components. The hardware components may include any suitable tangible components constructed or arranged to operate as described herein. Some hardware components (e.g., scheduler, schedule unit controller, schedule unit, synchronization unit, schedule unit, positioning unit, compensation unit, control unit, digital reception electronics, digital transmission electronics, etc.) may include processing circuitry (e.g., a processor or a group of processors) to perform the operations described herein. The software components may include code recorded on a tangible computer-readable medium. The processing circuitry may be configured by the software components to perform the described operations.

[0500] It is therefore intended that the present embodiments be considered in all respects as illustrative and not restrictive.

[0501] Reference numerals

[0502] 100 Positioning System

[0503] 110 Scheduler

[0504] 120 Dispatching Unit Controller

[0505] 130, 130a, 130b transceivers

[0506] 140, 140a, 140b Self-positioning device

[0507] 202 Positioning signal capable of time stamping

[0508] 210 clock

[0509] Antennas 212, 212a, and 212b

[0510] 214, 214a, 214b Transceiver analog transmission electronics

[0511] 216, 216a, 216b Transceiver digital transmission electronics

[0512] 218 Scheduling Unit

[0513] 220, 220a, 220b Transceiver Analog Receiver Electronics

[0514] 222, 222a, 222b Transceiver Digital Receive Electronics

[0515] 224 Transceiver Synchronization Unit

[0516] 226 Sensor

[0517] 228 Global Property Sensors

[0518] 230 transceiver memory

[0519] 302 Sending and Receiving Signals

[0520] 400 structural elements

[0521] 402a, 402b clock interface

[0522] 502, 502a, 502b, 502c Self-positioning device antenna

[0523] 504, 504a, 502b Self-positioning device simulation receiving electronic device

[0524] 506, 506a, 506b Self-positioning device digital receiving electronic device

[0525] 508 Self-positioning device clock

[0526] 510 Self-positioning device synchronization unit

[0527] 512, 512a, 512b Self-positioning device positioning unit

[0528] 514, 514a, 514b Self-positioning device vehicle-mounted sensor

[0529] 516 compensation unit

[0530] 518 Self-positioning device memory

[0531] 520 Global Property Sensor

[0532] 600 Progress of time measured in the clock of self-positioning device A

[0533] 602 Arrival time of the first message at the antenna of the self-positioning device A

[0534] 604 The difference between the time stamp of the first message from the digital receiving electronics of positioning device A and the arrival time of the first message at the antenna of positioning device A

[0535] 606 Time stamp of the first message received by the digital electronic device from the positioning device A

[0536] 612 Arrival time of the second message at the antenna of the self-positioning device A

[0537] 614 The difference between the time stamp of the second message by the digital receiving electronics of the self-positioning device A and the arrival time of the second message at the antenna of the self-positioning device A

[0538] 616 The time stamp of the second message received by the digital receiving electronic device of the self-positioning device A

[0539] 700 structural elements

[0540] 702 Communication Path

[0541] 800 RF Switch

[0542] 900 Receive Time Stamp

[0543] 902 Clock Correction

[0544] 904 Effect Compensation

[0545] 906 Corrected Arrival Time

[0546] 910 Remote Global Attributes

[0547] 912 Comparison

[0548] 914 Global Attribute Model

[0549] 920 Extended Kalman filter processing update

[0550] Before 922

[0551] 924 Extended Kalman filter measurement update

[0552] After 926

[0553] 930 position

[0554] 940 Control Unit

[0555] 1000 mobile robots

[0556] 1002 Central processing electronic devices

[0557] 1004 Actuator

[0558] 1006 Accelerometer

[0559] 1008 Gyroscope

[0560] 1010 Propeller

[0561] 1102 Level Controller

[0562] 1104 Command to specify vehicle acceleration in the x direction

[0563] 1106 Command to specify vehicle acceleration in the y direction

[0564] 1110 Vertical Controller

[0565] 1112 Command to specify vehicle acceleration in the z direction

[0566] 1120 Lowering the height controller

[0567] 1122 Command to specify vehicle pitch rate

[0568] 1124 Command to specify vehicle roll rate

[0569] 1130 Yaw Controller

[0570] 1132 Command to specify vehicle yaw rate

[0571] 1142 Body Speed ​​Controller

[0572] 1144 Actuator Command

[0573] 1146 Mobile

[0574] 1200 radial coverage of transmit and receive signals

[0575] 1210 Wireless communication between two transceivers within range

[0576] 1220 Overlapping spatial coverage by multiple transceivers within a cell

[0577] 1240 Overlapping spatial coverage via multiple transceiver cells

[0578] 1410 Overlapping spatial coverage by multiple transceivers within a cell

[0579] 1420 Overlapping spatial coverage via multiple transceiver cells

[0580] 1610 Input parameter plot with performance contours

[0581] 1620 Input parameter mapping with binary performance

[0582] 1710 Dynamic Positioning Performance Diagram

[0583] 1810 Panel

[0584] 1820a, 1820b location map

[0585] 1830a, 1830b Coverage Requirements Map

[0586] 1840a, 1840b Timeline

[0587] Location map of 1910a, 1910b, 1910c, and 1910d

[0588] 2010a, 2010b, 2010c, 2010d location maps

[0589] 2110 Positioning signal preamble

[0590] 2112 Positioning signal start frame delimiter (SFD)

[0591] 2114 Positioning signal packet header

[0592] 2116 Positioning signal payload

[0593] 2122 Positioning signal transmission start time

[0594] 2124 Positioning signal transmission end time

[0595] 2200 Transmission Schedule

[0596] 2202a, 2202b, 2202c, 2202d positioning signals

[0597] 2310 Receiver Activity

[0598] 2402a, 2402b, 2402c positioning signals

[0599] 2500 Positioning System

[0600] 2510 Performance Chart

[0601] 2610 Performance Chart

[0602] 2700 Positioning System

[0603] 2710 Performance Chart

[0604] 2810 Performance Chart

[0605] 2900 Transmission Schedule

[0606] 3000 Transmission Schedule

[0607] 3100 Flowchart

[0608] 3102 Flowchart Steps

[0609] 3104 Flowchart Steps

[0610] 3106 Flowchart Decision

[0611] 3108 Flowchart Steps

[0612] 3110 Flowchart Decision

[0613] 3112 Flowchart Steps

[0614] 3114 Flowchart Decision

[0615] 3116 Flowchart Steps

[0616] 3118 Flowchart Steps

[0617] 3210 Flowchart Steps

[0618] 3222 Flowchart Steps

[0619] 3124 Flowchart Steps

[0620] 3200 Indoor and outdoor environments

[0621] 3210 Buildings

[0622] 3220 Visited Areas

[0623] 3230 Aircraft

[0624] 3240 Landing Zone

[0625] 3250 Second Region

[0626] 3310 Positioning Network

[0627] 3320 Positioning Network

[0628] 3330 Bridge Anchor

Claims

1. A positioning system comprising: A plurality of positioning anchors configured to wirelessly transmit positioning radio signals that can be used by self-positioning devices within an area to determine position information, wherein: A first positioning anchor of the plurality of positioning anchors is configured to wirelessly transmit a first positioning radio signal; A second positioning anchor of the plurality of positioning anchors is configured to wirelessly transmit a second positioning radio signal; A third positioning anchor of the plurality of positioning anchors is configured to wirelessly transmit a third positioning radio signal; and Each of the plurality of positioning anchors is communicatively coupled to at least one scheduling unit, wherein the at least one scheduling unit is configured to: The transmission of positioning radio signals is scheduled to control positioning performance within the area by: scheduling a first positioning anchor to transmit a first positioning radio signal at a first transmission rate; scheduling a second positioning anchor to transmit a second positioning radio signal at a second transmission rate; and The third positioning anchor is scheduled to transmit a third positioning radio signal at a third transmission rate, wherein the first positioning anchor transmits more frequently than the second positioning anchor such that the first transmission rate is greater than the second transmission rate to compensate for uneven distribution of the plurality of positioning anchors. 2 . The positioning system of claim 1 , wherein the at least one scheduling unit is further configured to adjust a transmission rate of the positioning radio signal to change positioning performance within the area during operation.

3. The positioning system according to claim 1 or 2, wherein: The at least one scheduling unit is configured to adjust a transmission rate of positioning radio signals based on a known position of the self-positioning device.

4. The positioning system according to claim 1 or 2, wherein: The at least one scheduling unit is configured to receive a known location of the self-locating device. 5 . The positioning system of claim 2 , wherein the at least one scheduling unit is configured to adjust a transmission rate of positioning radio signals based on a known motion of the self-positioning device. The positioning system of claim 5 , wherein the motion is a flight mode.

7. The positioning system according to claim 1 or 2, wherein: The positioning radio signals include ultra-wideband (UWB) positioning radio signals, and each UWB positioning radio signal includes a preamble and a payload.

8. The positioning system according to claim 7, wherein: The payload of at least some of the UWB positioning radio signals includes commands, and wherein the at least one scheduling unit is configured to schedule transmission of the UWB positioning radio signals to optimize propagation of commands to at least one of the plurality of anchors and self-positioning devices.

9. The positioning system according to claim 7, wherein: Each of the plurality of positioning anchors comprises a clock, wherein a payload of at least some of the UWB positioning radio signals comprises synchronization data, wherein each of the plurality of positioning anchors is configured to receive the synchronization data in a UWB positioning radio signal received from at least one other positioning anchor, and wherein the at least one scheduling unit is configured to schedule transmission of the UWB positioning radio signals to optimize synchronization of the clocks.

10. The positioning system according to claim 9, wherein: Each of the plurality of positioning anchors comprises a synchronization unit, wherein each synchronization unit is configured to calculate a correction of at least one of a clock offset and a clock rate of its corresponding clock based on the received synchronization data.

11. The positioning system according to claim 1 or 2, wherein: The at least one scheduling unit is configured to schedule transmission of the positioning radio signals to increase at least one of precision, accuracy, or update rate within one or more portions of the area.

12. The positioning system according to claim 1 or 2, wherein: The at least one scheduling unit is configured to schedule transmission of positioning radio signals based on time slots in a schedule, wherein a first positioning anchor is allocated more time slots in the schedule than a second positioning anchor.

13. The positioning system according to claim 1 or 2, wherein: The at least one scheduling unit includes: a first scheduling unit, a second scheduling unit and a third scheduling unit, wherein the first scheduling unit is physically coupled to the first positioning anchor and is configured to schedule the transmission of the first positioning radio signal, wherein the second scheduling unit is physically coupled to the second positioning anchor and is configured to schedule the transmission of the second positioning radio signal, and wherein the third scheduling unit is physically coupled to the third positioning anchor and is configured to schedule the transmission of the third positioning radio signal.

14. The positioning system according to claim 1 or 2, wherein: The region comprises a three-dimensional region.

15. A method for transmitting positioning radio signals in a positioning system comprising a plurality of positioning anchors, the method comprising: wirelessly transmitting a first positioning radio signal using a first positioning anchor of the plurality of positioning anchors during two or more time slots of a transmission schedule; wirelessly transmitting a second positioning radio signal using a second positioning anchor of the plurality of positioning anchors during one or more time slots of the transmission schedule; and Wirelessly transmitting a third positioning radio signal using a third positioning anchor of the plurality of positioning anchors in one or more time slots of the transmission schedule: The first positioning radio signal, the second positioning radio signal and the third positioning radio signal can be used by a self-positioning device in the area to determine position information; and The first location anchor is allocated more time slots in the transmission schedule than the second location anchor to compensate for the uneven distribution of the plurality of location anchors.

16. The method according to claim 15, further comprising: One or more scheduling units are used during operation to adjust the number of time slots to which the first, second, and third location anchors are allocated in the transmission schedule.

17. The method according to claim 15 or 16, wherein The number of time slots is adjusted based on the known position of the self-locating device.

18. The method according to claim 15 or 16, further comprising: The known location of the self-locating device is wirelessly received.

19. The method according to claim 15 or 16, wherein The time slots of the transmission schedule are assigned based on one or more of: a known position of the self-locating device, optimization of propagation of commands included as part of at least some of the first, second, and third positioning radio signals, optimization of synchronization of clocks associated with the first, second, and third positioning anchors, and at least one of improved precision, accuracy, or update rate in one or more portions of the area.

20. The method according to claim 15 or 16, further comprising: generating a first timing signal using a first clock, the first timing signal being used to determine when the first positioning anchor wirelessly transmits a first positioning radio signal; generating a second timing signal using a second clock, the second timing signal being used to determine when the second positioning anchor wirelessly transmits a second positioning radio signal; and A third timing signal is generated using a third clock, the third timing signal being used to determine when a third positioning anchor wirelessly transmits a third positioning radio signal, wherein the first, second, and third clocks are synchronized.

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