Magnetic pose measurement by an electronic device

Abstract

The present disclosure relates, in one aspect, to an electronic device comprising: one or more electromagnetic coils for measuring a magnetic field generated by an electromagnetic coil of another electronic device; and a processing unit for calculating a pose of the electronic device relative to the other electronic device.

Description

[0001] In one aspect, this disclosure relates to an electronic device comprising one or more electromagnetic coils for measuring at least one magnetic field generated by one or more electromagnetic coils of another electronic device; and a processing unit for calculating the pose of the electronic device relative to the other electronic device. Background Technology

[0002] Electronic device systems are used in a variety of applications, particularly as modular wireless interactive toys.

[0003] In many cases, such as in the context of providing interactive games involving multiple toy elements, it is desirable to provide electronic devices with the ability to determine their pose relative to each other.

[0004] In this context, it is generally desirable to avoid the need for additional equipment (such as cameras, base stations, etc.) because such equipment may affect the value of the game, complicate user interaction with the device, and / or increase the complexity or manufacturing cost of the system.

[0005] WO 2020 / 156719 discloses a modular toy system comprising multiple separate electronic toy modules. Each electronic toy module includes a functional device operable to perform a user-perceptible function, and control circuitry for controlling the functional device. At least one first electronic toy module among the multiple electronic toy modules includes a first control circuitry, a first functional device, and a sensor system configured to non-contactly detect corresponding coordinate values ​​of at least two coordinates, each coordinate indicating the position or orientation of at least one second electronic toy module among the multiple electronic toy modules relative to the first electronic toy module. The first control circuitry is configured to control the operation of the first functional device based on the detected one or more coordinate values.

[0006] In the context of interactive toy systems, children or other users of the toy system can arrange multiple wireless interactive toy modules relative to each other and can repeatedly rearrange them, including in configurations that were not initially anticipated. For example, when the wireless interactive toy is a building block of the wireless interactive toy, children or other users can build various different toy building models, which may include multiple wireless interactive toys. Furthermore, users may move the toy modules relative to each other in sudden and often unpredictable ways. Therefore, it is beneficial when the interactive toy system can seamlessly handle a wide variety of situations without complex user configuration, while ensuring the proper functioning of the toy system. In particular, pose estimation performed by the wireless interactive toy should be performed reliably and efficiently.

[0007] Electromagnetic pose detection provides a practical and cost-effective mechanism for this pose determination, with the potential to provide a large working range without line-of-sight between electronic devices. An example of this mechanism is disclosed in W. Kim, J. Song, and FC Park, "Closed-Form Position and Orientation Estimation for a Three-Axis Electromagnetic Tracking System," in IEEE Transactions on Industrial Electronics, vol. 65, no. 5, pp. 4331-4337, May 2018, doi:10.1109 / TIE.2017.2760244. However, existing mechanisms for electromagnetic pose detection suffer from inherent ambiguity in the detected pose.

[0008] Such ambiguity can confuse users. For example, in the context of modular interactive toys, when a user manipulates and moves two or more toy modules, the user typically expects the modules to react in a predictable way, and for this reaction to correspond to the modules' movements relative to each other—for example, whether two toys are facing each other or back to back. Ambiguous pose estimations can lead to inconsistent responses and thus a confusing and unpleasant user experience.

[0009] The general expectation is to provide an electronic device and an electronic device system, particularly an interactive wireless toy, that is robust and reliable in operation.

[0010] It is also desirable to provide an electronic device and electronic device system that operate with low power consumption.

[0011] It is also desirable to provide an electronic device and electronic device system that requires less communication overhead.

[0012] It is also desirable to provide an electronic device system that can be easily operated by users, especially children, and requires little or no user configuration.

[0013] It is also desirable to provide an electronic device and electronic device system that can be manufactured at low cost.

[0014] There is also a desire to provide an electronic device with a smaller form factor, for example, small enough to be easily grasped and held by a toddler's hand.

[0015] It is also desirable to provide an electronic device system that is scalable and capable of handling a constantly changing number of electronic devices.

[0016] In this context, despite previous efforts, there is still a desire to provide an electronic device and a system of such devices that solves one or more of the problems mentioned above and / or other problems, and / or has other benefits, or at least provides an alternative to existing solutions. Summary of the Invention

[0017] According to one aspect, this disclosure relates to an electronic device comprising: - One or more electromagnetic coils for measuring at least one magnetic field generated by one or more electromagnetic coils of another electronic device; - A processing unit for calculating the pose of the electronic device relative to the other electronic device.

[0018] According to various embodiments of the electronic device, at least one of one or more electromagnetic coils is configured to measure gradient information of at least one measured magnetic field; and wherein a processing unit is configured to calculate pose based on the at least one measured magnetic field and based on the measured gradient information.

[0019] The inventors have recognized that pose estimation based on the measured magnetic field and the measured gradient information provides a reliable pose estimation, which solves the pose ambiguity of existing methods.

[0020] One or more electromagnetic coils of an electronic device measure magnetic field and gradient information at at least one location of the electronic device, wherein the magnetic field is generated by an electromagnetic coil of the other electronic device, particularly by an electromagnetic coil located within the other electronic device. The other electronic device may generate magnetic fields sequentially by multiple coils, which may have different orientations relative to each other; thus, multiple fields can be generated, and the electronic device can therefore measure multiple fields.

[0021] The measured magnetic field can represent one or more measured components indicating the magnetic field strength, i.e., one or more measured magnetic field components. The measured magnetic field components may include phase information about the time-varying magnetic field and / or information about the direction of the magnetic field. For the purposes of this specification, the magnetic field components may be represented as components of the magnetic field strength vector H or the magnetic flux density vector B, or otherwise. Field measurements can provide information about the components of the magnetic field strength vector or magnetic flux density vector along one or more directions. Therefore, the measured magnetic field refers to a measurement indicating the magnetic field components measured by an electronic device.

[0022] Gradient information may include any information indicating spatial variations in the magnetic field at the location of the electronic device (e.g., spatial variations within the electronic device). Gradient information may include information about the gradient vector of the magnetic field, or other information indicating spatial variations in the magnetic field within the electronic device. Gradient information may include directional information about the spatial gradient direction of the magnetic field at the location of the electronic device (e.g., the magnetic field strength vector or magnetic flux density vector, or components thereof). Directional information may be represented, for example, by a symbol or other indication to indicate the direction of the gradient component along the axis of one or more corresponding electromagnetic coils, or otherwise. For example, directional information may indicate whether the component of the gradient vector along the coil axis is positive or negative. Gradient information may also include information about the gradient magnitude, such as the magnitude along the axis of the corresponding coil.

[0023] In some embodiments, the electronic device includes more than one coil, such as three or more coils. Preferably, each of the three coils defines a coil axis, and the three coils are arranged such that their respective coil axes are linearly independent, for example, orthogonal to each other. Therefore, the electronic device can perform pose determination in more than one dimension, particularly in three dimensions. Pose determination can be the determination of six degrees of freedom, particularly three directional degrees of freedom and three orientation degrees of freedom.

[0024] For the purposes of this disclosure, the terms "pose" and "pose determination" are intended to refer to the determination of information regarding the position and / or orientation of an electronic device relative to another electronic device. Information regarding position may include orientation and / or distance between the electronic devices. Orientation may be represented as the direction of the position vector of the electronic device relative to the coordinate system of the other electronic device, or otherwise. Orientation may be represented as a rotation of the coordinate system of the electronic device relative to the coordinate system of the other electronic device, or otherwise. It should be understood that in some cases, the electronic device may only require partial pose information, such as information only regarding the distance between the electronic devices. In this case, the electronic device can calculate partial pose information. In other cases, the electronic device may require complete pose information, i.e., information regarding distance, orientation, and orientation. In this case, the electronic device can therefore calculate the complete pose.

[0025] As will be described in more detail herein, pose determination based solely on magnetic field components (including the direction of the magnetic field vector) can lead to ambiguous poses. In particular, ambiguity affects the determination of orientation between two electronic devices, as calculations yield two solutions for the orientation between the devices, both of which are consistent with the measured magnetic field. Gradient information can be used to resolve the aforementioned ambiguity in orientation determination. Therefore, in some embodiments, the calculation of partial or complete pose includes calculating the relative orientation between at least one other electronic device and the electronic device, wherein the calculation of this orientation is based on at least one measured magnetic field component and measured gradient information.

[0026] Gradient information can be obtained in a variety of ways. For example, one or more electromagnetic coils used to measure at least one magnetic field can be configured to provide magnetic field measurements at corresponding locations relative to an electronic device, or otherwise obtain measurements indicating changes in the magnetic field, such as changes in direction relative to one or more electromagnetic coils, or changes in the axial direction of one or more electromagnetic coils.

[0027] For this purpose, an electronic device may include at least one set of coils arranged in series with each other. The coils in this set of coils may be arranged coaxially with each other or otherwise. The set of coils may be a pair of two coils or include more than two coils. The set of coils may define at least two measurement nodes for measuring corresponding electrical signals, such as a measurement node associated with each coil in the set of coils, or otherwise.

[0028] Alternatively or additionally, the electronic device may include at least one coil that defines at least two measuring nodes at corresponding locations along the coil, such as at one end of the coil and at the center of the coil. Thus, a coil portion can be considered as two coil portions connected in series. The measuring nodes can be associated with corresponding coil portions of at least one coil.

[0029] In some embodiments, gradient measurement may therefore involve more than one field measurement, which may be performed simultaneously or sequentially.

[0030] Electronic devices may include magnetic field measurement circuitry configured to measure electrical signals, such as voltages, at corresponding measurement nodes associated with corresponding coils in a set of coils and / or at corresponding measurement nodes associated with corresponding coil portions of a single coil. In some embodiments, the magnetic field measurement circuitry is configured to measure differential voltages between two pairs of measurement nodes. One of the measurement nodes may be shared for both measurements. In some embodiments, the magnetic field measurement circuitry is configured to measure electrical signals at measurement nodes relative to a suitable reference (e.g., ground). Measurement nodes may be located at different points (tap) along the coil, such as at one end of the coil, or at any point along its length.

[0031] As described above, in some embodiments, the measurement circuit includes two or more coils connected in series, optionally with one or more additional electronic components connected in series between them. In this embodiment, one or more measurement nodes may be located at nodes between different coil pairs, and / or at the ends of the series-connected coils.

[0032] In one embodiment, one node of the circuit is a reference node, which may be grounded, and the measurement circuit is configured to measure the differential voltage between a first measurement node and the reference node, as well as the differential voltage between a second measurement node and the reference node.

[0033] The first measuring node can be located at one end of the coil or at one end of a group of coils connected in series, while the second measuring node can be positioned along the coil between its two ends or between two coils connected in series. For example, the second measuring node could be a centrally located measuring node between the ends of the coil. The second measuring node can be formed as a coil tap, such as a center tap. Thus, the electronic device can measure not only the overall magnetic field but also the change in magnetic field along the coil axis or between coils connected in series, thereby obtaining gradient information indicating whether the magnetic field component along the coil axis is greater at one end of the coil (or at one coil in a group of coils) than at the opposite end of the coil (or at another coil in the group of coils). It should be understood that other measuring arrangements can be used to obtain gradient information.

[0034] According to some embodiments, the coil set comprises a set of two coils that may be spaced apart from each other, for example, axially spaced apart. The two coils may be arranged coaxially. The two coils in the set are preferably arranged such that the electromotive force induced in the respective coils of the set is different in two ambiguous poses, specifically such that the difference between the magnetic fields at the two coils depends on which of the two ambiguous poses the electronic device is in. For this purpose, the two coils may be arranged in series with each other. The two coils may be spaced apart from each other, with a gap between them, for example, a gap greater than 1 mm, or a gap greater than 2 mm. For example, these coils may be arranged near opposite sides of the housing of the electronic device, thereby maximizing the distance between the coils. The coils constituting the set may have the same inductance or otherwise be the same, or they may be different from each other. The measurement node may be located between the two coils, for example, on the wire or circuit that electrically connects the two spaced-apart coils. Therefore, reliable gradient information can be obtained.

[0035] In some embodiments, one or more electromagnetic coils include three sets of coils, particularly three pairs of coils. Each set may include two spaced-apart coils connected in series. In some embodiments, each of the three sets of coils defines a coil axis, and the three sets of coils are arranged such that their respective coil axes are linearly independent, for example, orthogonal to each other. Typically, some embodiments of electronic devices are configured to perform three magnetic field measurements and three gradient measurements for each magnetic field generated by another electronic device (e.g., for each of three magnetic fields).

[0036] Existing methods for calculating pose information based on measured magnetic fields suffer from ambiguity in the determined pose. Specifically, these methods yield two solutions, particularly those corresponding to the electronic device being in a diameter-opposite (diameter-opposite) position relative to another electronic device generating at least one magnetic field. In some embodiments of the electronic devices disclosed herein, additional gradient information is used to eliminate the ambiguity between these two solutions. Therefore, in some embodiments, the processing unit is configured to calculate pose information indicating two candidate poses and, based at least on the measured gradient information, select one of the candidate poses as the calculated pose. The calculation of the candidate poses can be performed based on, and particularly solely on, the measured magnetic field components (including relative orientation and / or relative phase information of the magnetic field vectors), while the selection of one of the candidate poses can be based on the gradient information.

[0037] In some embodiments, the processing unit is also configured to calculate one or more confidence values ​​associated with the calculated pose (e.g., associated with a selected candidate pose), thereby allowing downstream processing steps utilizing pose information to take any action based on the confidence that the determined pose is accurate. Specifically, downstream processing can take one or more actions based on the calculated pose and the calculated one or more confidence values. This can be useful, for example, when the determined pose changes abruptly. In this case, the downstream processing can decide whether to rely on information about the determined abrupt change or ignore it as a possible result of noise measurement. The one or more confidence values ​​may include, for example, an accuracy measure of a certain aspect of the pose (e.g., distance), and / or the one or more confidence values ​​may include confidence values ​​indicating that a correct candidate pose has been selected.

[0038] In some embodiments, the processing unit is configured to repeatedly perform pose estimation to generate a time series of calculated poses, thereby allowing the electronic device to track relative poses over time and thus allow the electronic device to react to changes in relative poses. In some embodiments, the processing unit is configured to calculate the current pose in the time series of the calculated poses based on a current set of one or more measurements of at least one magnetic field and one or more previous poses in the time series of poses. Thus, the processing unit can implement a tracking mechanism that uses one or more previously determined poses as input to the calculation of the current pose measurement, for example, by applying a suitable filter or otherwise. This allows the process to avoid erroneous determinations of sudden changes in pose. In some embodiments, the processing unit is configured to perform the calculation of two current candidate poses based on a current measurement of at least one magnetic field (e.g., field components, including relative phase and / or field direction) and one or more previous poses. Alternatively or additionally, the processing unit may be configured to perform a selection of one of two current candidate poses, based at least on the current measurement of gradient information and one or more previous poses in the time series of the pose. These two current candidate poses are obtained from one or more current measurements of at least one magnetic field (e.g., magnetic field components along one or more directions, including phase information). Thus, the processing unit can implement a tracking mechanism that uses one or more previously determined poses as disambiguation inputs to the current pose measurement.

[0039] The calculation of the current candidate pose can also be based on the corresponding confidence value associated with the current and / or one or more previous candidate poses. Similarly, the selection of one of the two current candidate poses can also be based on the corresponding confidence value associated with the current and / or one or more previously selected candidate poses.

[0040] According to some embodiments, the processing unit includes a data storage device storing a set of one or more device-specific calibration parameters, and wherein the processing unit is configured to further calculate candidate poses and / or select one of the candidate poses based on the stored set of one or more device-specific calibration parameters. The one or more device-specific calibration parameters may include one or more calibration parameters specific to an electronic device. Alternatively or additionally, the one or more device-specific calibration parameters may include one or more calibration parameters specific to the other electronic device. For this purpose, the electronic device can receive the one or more device-specific calibration parameters from the other electronic device. For example, the other electronic device may wirelessly transmit (e.g., broadcast) its one or more device-specific calibration parameters, particularly via a wireless communication network. Examples of device-specific calibration parameters may include field calibration values ​​associated with the emission intensity of a magnetic field emitted by the other electronic device and / or calibration parameters associated with the receiving sensitivity of a magnetic field measured by the electronic device.

[0041] In some embodiments, the electronic device includes a wireless communication interface configured to communicate wirelessly via a wireless communication network, and wherein the electronic device is configured to communicate wirelessly with one or more other electronic devices via the wireless communication network. Thus, the electronic device can receive calibration parameters and / or other information from, for example, another electronic device. Examples of other information may include a timing schedule indicating when another electronic device generates a magnetic field and / or when the electronic device should measure one or more magnetic fields generated by another electronic device. This timing schedule may be a shared timing schedule, shared among multiple electronic devices as described herein.

[0042] This disclosure relates to various aspects, including electronic devices, corresponding apparatuses, systems, methods, and / or products described above and below, each aspect producing one or more benefits and advantages in conjunction with one or more other aspects, and each aspect having one or more embodiments corresponding to the embodiments described in conjunction with one or more other aspects and / or disclosed in the appended claims.

[0043] In particular, according to one aspect, embodiments of systems of such electronic devices are disclosed herein. In some embodiments, some or all of the electronic devices of the system are configured to perform corresponding pose estimations as disclosed herein.

[0044] Specifically, this document discloses embodiments of an electronic device system comprising multiple electronic devices, including at least one receiver electronic device and at least one transmitter electronic device. The receiver electronic device is an electronic device as disclosed herein, wherein the transmitter electronic device includes one or more electromagnetic coils for generating one or more magnetic fields, wherein at least one of the electromagnetic coils of the receiver electronic device is configured to measure at least one of the one or more magnetic fields generated by the transmitter electronic device and to measure gradient information of the measured at least one magnetic field, and wherein a processing unit of the receiver electronic device is configured to calculate the pose of the receiver electronic device relative to the transmitter electronic device based on the measured at least one magnetic field and based on the measured gradient information. For the purposes of this specification, the term "transmitter electronic device" is intended to refer to an electronic device that generates one or more magnetic fields via one or more electromagnetic coils of the transmitter electronic device. Therefore, the generation and radiation of magnetic fields by the transmitter electronic device is also referred to as the emission of magnetic fields.

[0045] In some embodiments, one or more electronic devices may operate only as receiver electronic devices. Alternatively or additionally, one or more electronic devices may operate only as transmitter electronic devices. Also alternatively or additionally, one or more electronic devices may selectively operate as transmitter electronic devices or as receiver electronic devices. For example, the processing unit of the electronic device may control the electronic device to operate as a transmitter electronic device or as a receiver electronic device, such as alternately, according to a timing schedule, or otherwise. In some embodiments, each electronic device in the electronic device may selectively operate as a transmitter electronic device or as a receiver electronic device, thereby making the system scalable and flexible.

[0046] Each electronic device can move independently of the other electronic devices in the system within space. In some embodiments, the system is an interactive toy system, and one or more (e.g., all) of the electronic devices are wireless interactive toys. In particular, the interactive toy system can be an interactive toy building system, and each wireless interactive toy is a wireless interactive toy building element or includes wireless interactive toy building elements. For example, the wireless interactive toy can be a single interactive toy building element, or a toy building model constructed from two or more toy building elements of the toy building system (including at least one interactive toy building element).

[0047] In the context of an interactive toy system, a user can move a wireless interactive toy around as part of a play experience. The wireless interactive toy can be configured to detect user interactions with components of the interactive toy system and respond to detected interactions by providing user-perceptible outputs, such as auditory, visual, and / or tactile outputs. In embodiments where the wireless interactive toy is a toy building element of a toy building system or is constructed from multiple toy building elements, the user can repeatedly attach and / or detach the wireless interactive toy building element from each other, and / or attach it to and / or detach it from other toy building elements of the toy building system to build and deconstruct different spatial structures. Spatial structures constructed from two or more toy building elements will also be referred to as toy building models. They can be repeatedly built and disassembled without destroying the toy building elements that assemble them.

[0048] Therefore, it is highly desirable for wireless interactive toys to have short response times to changes in the relative positions of the wireless interactive toys, so that when the user moves the components of the toy system relative to each other, the user perceives an immediate and detectable response. Thus, it is desirable for wireless interactive toys to reliably perform pose estimation operations at a sufficiently high rate to facilitate fast response times.

[0049] Magnetic pose estimation operations can have a pose estimation range, i.e., the maximum range within which one electronic device can still determine the relative pose of another electronic device. For example, the pose estimation range can be at least 1 m, such as at least 2 m, such as at least 5 m. However, other embodiments can have different ranges. Furthermore, in some embodiments, the effective ranges of different aspects of pose determination (e.g., distance, direction, orientation, disambiguation) can be different from each other.

[0050] In some embodiments, the electronic devices can be configured to perform pose estimation operations in a cooperative manner. For this purpose, one or more electronic devices (e.g., each electronic device) can be configured to output at least one magnetic field that can be sensed by one or more other electronic devices. Furthermore, one or more electronic devices (e.g., each electronic device) can be configured to sense at least one magnetic field output by another electronic device and calculate at least its relative pose relative to the other electronic device, based at least on the sensed magnetic field. The relative pose can include the relative position of the electronic devices and optionally, relative orientation.

[0051] Electronic devices can share information about their calculated poses via wireless communication interfaces. For example, an electronic device can i) measure one or more magnetic fields generated by another electronic device, process those measurements to calculate an estimated pose, and then ii) share the calculated estimated pose with other electronic devices using a wireless communication network. Then iii) these other electronic devices can use these pose estimates to help them determine their own poses.

[0052] Typically, one or more magnetic fields generated by a transmitting electronic device can be time-varying magnetic fields with a predetermined frequency. In some embodiments, at least one first electronic device among a plurality of electronic devices is configured to measure ambient electromagnetic signals during times when at least one transmitting electronic device is not generating a magnetic field (particularly when none of the plurality of electronic devices is generating a magnetic field); wherein the first electronic device includes a processing unit configured to select a target frequency based on the measured ambient electromagnetic signal and transmit the selected target frequency to other electronic devices among the plurality of electronic devices; and wherein the transmitting electronic device is configured to generate a magnetic field as a time-varying magnetic field at the transmitted target frequency, and wherein at least one receiver electronic device is configured to measure the magnetic field at the transmitted target frequency.

[0053] Each electronic device may include a transmitter or other signal generator coupled to one or more electromagnetic coils for causing the one or more electromagnetic coils to generate a magnetic field. The electronic device may include receiver circuitry coupled to one or more electromagnetic coils for sensing the magnetic field generated by another electronic device. The transmitter and receiver may be configured as separate circuits or as a single combined circuit, such as a transceiver circuit. The transmitter and / or receiver circuitry may be implemented at least partially by a processing unit and / or at least partially by one or more separate electronic circuits.

[0054] Electronic devices can use sensed pose information to detect user interactions with the device and determine interactive responses to detected user interactions, such as as part of a gaming experience performed by the electronic device.

[0055] In some embodiments, at least one first receiver electronic device is configured to: - Measure the magnetic field generated by the first and second transmitter electronic devices among a plurality of electronic devices; - Receive disambiguated pose information about the relative poses of the first transmitter electronics and the second transmitter electronics with respect to each other; - Based at least on the measured magnetic field and the received disambiguated pose information, the corresponding disambiguated pose of the first receiver electronic device relative to the first transmitter electronic device and the second transmitter electronic device is calculated. Therefore, disambiguated information created by one electronic device can be used by another electronic device to disambiguate its own relative pose; that is, the disambiguated information can propagate within the electronic device system. Thus, the reliability of pose determination is improved, which may be particularly useful when some electronic devices are far apart, causing the measurement of gradient information to become relatively noisy.

[0056] In some embodiments, at least one transmitter electronics is configured to acquire (e.g., receive, retrieve from internal memory, or determine) one or more field calibration values ​​of at least one generated magnetic field, and transmit the acquired one or more field calibration values ​​to at least one receiver electronics; and wherein a processing unit of the at least one receiver electronics is configured to calculate the pose of the receiver electronics relative to the transmitter electronics based at least on the received one or more field calibration values. The field calibration values ​​may be static values ​​determined at manufacturing time and stored in the electronics. Alternatively or additionally, the field calibration values ​​may include dynamic values ​​that may depend on factors such as the battery level of the electronics, operating temperature, etc. Such dynamic values ​​may be determined by the electronics during operation.

[0057] In some embodiments, at least one receiver electronic device is configured to transmit its calculated pose to a transmitter electronic device (to which the receiver electronic device has already calculated its pose) and / or to one or more other electronic devices among a plurality of electronic devices. Thus, the plurality of electronic devices can collaboratively measure relative pose information and share the measured information with each other, allowing the system to determine the relative pose of the plurality of electronic devices in an efficient manner. This, in turn, allows for relatively frequent measurements.

[0058] In some embodiments, the electronic devices are configured to communicate wirelessly with each other via a wireless communication network. Therefore, in some embodiments, each electronic device includes a wireless communication interface configured to communicate wirelessly via the wireless communication network, and wherein the electronic devices are configured to communicate wirelessly with each other via said wireless communication network. The wireless communication may be based on suitable radio frequency communication technologies, such as Bluetooth, Bluetooth Low Energy, ZigBee, Wi-Fi, etc. In some embodiments, the wireless communication may include one or more messages being broadcast by one or more electronic devices to other electronic devices among a plurality of electronic devices via the wireless communication network. The wireless communication interface may include a radio transceiver (e.g., a Bluetooth chip or circuitry) and an associated antenna, particularly an antenna different from one or more electromagnetic coils.

[0059] Wireless communication between electronic devices can be short-range wireless communication, having a communication range of, for example, less than 100 m or less than 10 m. However, the communication range is preferably greater than the effective range of the pose sensing operation. In some embodiments, the communication range can be at least 2 m, for example, at least 3 m or at least 5 m.

[0060] Electronic devices can use wireless communication networks to coordinate the operation of electronic device systems. For example, multiple electronic devices can be configured to share calibration parameters and / or timing schedules for scheduling magnetic fields generated by one or more respective transmitter electronic devices via the wireless communication network. Alternatively or additionally, multiple electronic devices can be configured to share measured distance information and / or additional pose information via wireless communication, optionally including confidence information regarding the shared pose information.

[0061] Wireless communication networks can be open networks, meaning that electronic devices can join and leave the network at any time; that is, the number of electronic devices within the communication network can change over time, optionally reaching a predetermined maximum number of electronic devices. Wireless communication networks can also be closed, meaning that only electronic devices within an electronic device system can join and communicate via the wireless communication network. The latter can be enforced, for example, by requiring predetermined identifiers, addresses, keys, encryption schemes, etc.

[0062] The timing schedule can be shared by at least a subset, or even all, of the electronic devices, for example, by all electronic devices currently communicating with each other via the same wireless communication network. In some embodiments, the multiple electronic devices include a scheduler device configured to create a shared timing schedule and distribute / broadcast the shared timing schedule to other electronic devices among the multiple electronic devices, for example, via the wireless communication network. Specifically, in some embodiments, at least one electronic device is configured to create a timing schedule and transmit the created timing schedule to at least one receiver electronic device and / or at least one transmitter electronic device; at least one transmitter electronic device may be configured to temporarily generate a magnetic field according to the transmitted timing schedule; and at least one receiver electronic device may be configured to measure the generated magnetic field based on the transmitted timing schedule.

[0063] It should be understood that a shared timing schedule can be created in a variety of ways. For example, the timing schedule can be predetermined and / or static, or it can be dynamic, such as adapting to the number of electronic devices currently participating in the wireless communication network, adapting to the current gaming experience, etc.

[0064] In some embodiments, the shared timing schedule includes reserved time for performing one or more different types of contactless sensing operations. For example, in some embodiments, the shared timing schedule includes reserved time for wireless tag sensing operations and reserved time for performing magnetic pose sensing operations.

[0065] Sharing timing schedules among electronic devices allows each device to perform cooperative non-contact sensing operations synchronously, particularly the pose measurement described herein.

[0066] The processing unit of an electronic device can be implemented as any suitable processing circuit or device, such as one or more properly programmed microprocessors or other processing devices, such as one or more ASICs, one or more microcontrollers and / or one or more other suitable processing units, or combinations thereof.

[0067] In some embodiments, the electronic device is a wireless interactive toy, particularly a wireless interactive toy building element. Therefore, according to another aspect, this disclosure relates to a toy building system comprising a plurality of wireless interactive toy building elements disclosed herein. The toy building system may include additional toy building elements, including toy building elements that do not perform any electronic functions, such as conventional toy building elements.

[0068] Each toy building element of a toy building system, particularly each wireless interactive toy building element, may include a connecting member configured to engage with connecting members of other toy building elements in the toy building system, so as to detachably attach the toy building elements to each other. For this purpose, the connecting members may utilize different engagement mechanisms, such as frictional engagement based on the connecting members themselves, screw-based, plug-and-socket connections, or other forms of mating engagement with the connecting members.

[0069] Therefore, toy building elements that have been interconnected by means of connecting members can be disconnected from each other again, allowing them to interconnect again or with other toy building elements in the system, for example, to form different spatial structures. In some embodiments, the toy building elements are provided with a first type of connecting member and a second type of connecting member, such as connecting tabs and tab receiving recesses for frictionally engaging the tabs, or other mating or otherwise complementary pairs of connecting members configured to engage each other to form a physical connection. One type of connecting member may be located on one side (e.g., the top side) of the toy building element, while another complementary type of connecting member may be located on the opposite side (e.g., the bottom side) of the toy building element. In some embodiments, the toy building element includes tabs extending from the top surface of the toy building element and corresponding tab receiving cavities extending into the bottom surface of the toy building element for frictionally engaging the tabs by a suitable clamping force.

[0070] Typically, toy building systems can impose restrictions on the degrees of freedom of how toy building elements can attach to each other, for example, by restricting the possible relative positions and / or orientations of their attachment. These restrictions can help detect the relative poses of electronic toy building elements within a toy building model. For this purpose, connecting members can be positioned at grid points of a regular mesh; specifically, connecting members of toy building elements can be arranged such that the connecting members of a set of interconnected toy building elements are positioned at grid points of a three-dimensional regular mesh. The dimensions of the toy building elements can be defined as integer multiples of the unit length defined by the regular mesh. It should be understood that the three-dimensional mesh can be defined by a single unit length, or by two unit lengths, for example, one unit length for two spatial dimensions and another unit length for a third spatial dimension. Alternatively, the three-dimensional mesh can be defined by three unit lengths, one unit length for each spatial dimension.

[0071] In some embodiments, the toy building elements are made of a plastic material (e.g., a thermoplastic polymer) or another suitable material. At least one housing of the toy building element, particularly a wireless interactive toy building element, can be made, for example, by injection molding or another suitable manufacturing process.

[0072] Each wireless interactive toy building element may include a housing. Each wireless interactive toy building element may include functional devices and / or sensor systems housed within the housing. Each wireless interactive toy building element may include a processing unit housed within the housing. Each wireless interactive toy building element may include one or more electromagnetic coils housed within the housing. Each wireless interactive toy building element may include a wireless communication interface housed within the housing. Each wireless interactive toy building element may include a power source, such as a battery, housed within the housing, which may be rechargeable. The housing may be box-shaped or have other suitable shapes. The housing may define a top surface and a bottom surface opposite the top surface. At least some of the connecting members may extend from the top surface. The housing may also include one or more sides extending between the top and bottom surfaces. In some embodiments, all wireless interactive toy building elements are configured to be interchangeably and detachably connected to other toy building elements of the toy building system.

[0073] The embodiments of the systems described herein provide distributed control for coordinating contactless sensing operations. Distributed control requires minimal or no user configuration, and is robust, reliable, and efficient. Attached Figure Description

[0074] The embodiments of the various aspects disclosed herein will be described in more detail with reference to the accompanying drawings, wherein: Figure 1An example of an electronic device in the form of a wireless interactive toy building block is shown; Figure 2 A schematic block diagram showing an example of an electronic device formed as a building element of a wireless interactive toy; Figure 3 Two wireless interactive toy building elements are shown; Figure 4 An exploded view schematically illustrates an example of an electronic device in the form of a wireless interactive toy building block; Figure 5 A schematic diagram of an embodiment of an electronic device is shown; Figure 6 The magnetic timing sequence is illustrated schematically; Figure 7 A schematic flowchart illustrating an example of the pose measurement process is shown; Figure 8 A system of two electronic devices with two candidate poses is schematically illustrated; Figures 9A to 9B An electromagnetic coil with a central measuring node is schematically shown; Figures 10A to 10B An example of pose tracking is shown; Figure 11 Another example of pose tracking, including disambiguation tracking, is illustrated schematically; Figure 12 An example of how an electronic device can utilize this received pose information is shown. Detailed Implementation

[0075] Various aspects and embodiments of an interactive toy system comprising multiple interactive wireless toys will now be described with reference to toy building blocks in the form of building elements. In this particular embodiment and corresponding embodiments, the electronic device is each formed as a corresponding wireless interactive toy building element, each having a housing generally shaped as an orthogonal polyhedron with flat sides, and having connecting members extending from its top surface and cavities extending into its bottom surface. However, wireless interactive toy building elements of other shapes and sizes can be used, such as box-shaped or plate-shaped toy building elements of different sizes and different numbers of connecting members. Furthermore, while the block shape has proven particularly useful, the various aspects disclosed herein can be applied to other forms of electronic devices, including other forms of toy building elements for gaming applications, educational applications, etc.

[0076] Figure 1 An example of an electronic device in the form of a wireless interactive toy building block is shown, generally designated as 100. Figure 1On the left, the wireless interactive toy building element is shown with its top surface visible, while on the right, it is shown with its bottom surface visible. Specifically, the wireless interactive toy building element includes a generally box-shaped housing 101 having connecting protrusions 104 extending from its top surface and a cavity extending from its bottom into the element. This cavity is defined by sidewalls 102 and a downwardly extending central tube 103. Connecting protrusions of another toy building element can be received in the cavity in a frictionally engaged manner, as disclosed, for example, in US 3,005,282. The building elements shown in the remaining figures have this known type of connecting member in the form of mating protrusions and cavities. However, other types of connecting members may be used in addition to or in place of protrusions and cavities. The connecting protrusions are arranged in a square planar grid on the top surface, defining the orthogonal direction along which the series of connecting protrusions are arranged. The distance between adjacent connecting protrusions is uniform and equal in both directions. This arrangement of connecting members, or similar arrangements, at the connection points of a defined regular planar mesh allows toy building elements to be interconnected in discrete numbers of positions and orientations relative to each other (particularly perpendicular to each other). In an assembled toy building model, the connecting members of multiple toy building elements can therefore be located at mesh points relative to the three-dimensional mesh defined by the toy building model.

[0077] In some embodiments, the housing 101 of the wireless interactive toy building element is made of a plastic material (e.g., a thermoplastic polymer) or another suitable material. The housing may be made, for example, by injection molding or another suitable manufacturing process.

[0078] The wireless interactive toy building element 100 may include a functional device 105 housed within a housing 101 of the wireless interactive toy building element. Typically, the functional device can be any suitable device for performing a function, such as providing a user-perceived effect, like a visual and / or auditory effect. Examples of functional devices may include any suitable mechanical and / or electrical equipment, arrangement, and / or circuitry adapted to perform one or more mechanical and / or electrical functions.

[0079] Examples of mechanical functions include driving a rotatable output shaft, winding a rope or chain to pull an object closer to a toy module, and moving the hinged parts of a wireless interactive toy building block. Therefore, mechanical functions can enable opening or closing doors, ejecting objects, rotating turntables, and moving linear actuators. This mechanical movement can be driven by an electric motor.

[0080] Examples of electrical functions include emitting continuous or flashing light, activating several lights in a predetermined sequence, emitting audible sounds such as buzzing, alarms, ringing, sirens, voice messages, music, synthesized sounds, simulated and / or natural or mimicked sounds that stimulate game activity, sound playback, and / or other audio content.

[0081] Therefore, the functional device can be selected from motors, light sources (such as one or more LEDs), and sound sources (such as speakers). A functional wireless toy building element may include more than one functional device. In some embodiments, the system includes different types of wireless interactive toy building elements, each of which includes a different type of functional device.

[0082] The wireless interactive toy building element 100 includes a sensor system 108, which includes one or more sensors housed within a housing 101 of the wireless interactive toy building element. The sensor system 108 may include one or more sensors, such as the magnetic pose sensor described herein and / or one or more other sensors, such as linear encoders or rotary encoders, light detectors and sound detectors (e.g., microphones), accelerometers, etc.

[0083] Figure 2 Electronic devices (e.g., those formed as building blocks for wireless interactive toys) are shown. Figure 1 The schematic block diagram of an example of a wireless interactive toy building element is shown, generally labeled 100.

[0084] The wireless interactive toy building element 100 includes a housing 101 defining a top surface, on which a connecting member 104 is disposed, as described above. Figure 1 The wireless interactive toy building element 100 also includes a processing unit 209 and one or more electromagnetic coils 207, all housed within the housing 101. The wireless interactive toy building element may also include one or more additional sensors 108 and / or one or more functional devices 105, also housed within the housing 101, such as those described above. Figure 1 The sensor system and functional devices described in the embodiments. The wireless interactive toy building element 100 also includes a rechargeable battery 210 or other rechargeable power source, and a wireless communication interface 211, which are also housed within the housing 101.

[0085] Each electromagnetic coil 207 defines a coil axis around which the electromagnetic coil extends. In this example, the electromagnetic coils 207 are arranged such that one coil extends its coil axis out of the top surface of the housing, while another coil extends its coil axis out of one side of the housing. A third electromagnetic coil ( Figure 2(Not explicitly shown herein) can be arranged such that their coil axes extend out of the other side of the housing, for example, such that the axes of all three coils are orthogonal to each other or at least linearly independent of each other. In this way, the wireless interactive toy building element can use electromagnetic coils to detect the pose coordinates of another wireless interactive toy building element having a similar electromagnetic coil arrangement as described herein. However, it should be understood that other coil arrangements are possible. In some embodiments, the wireless interactive toy can use one or more electromagnetic coils to perform additional functions, such as detecting, identifying, and / or capturing data from a wireless tag. Furthermore, the wireless interactive toy building element can receive electrical energy via one or more electromagnetic coils 207 to charge the battery 210, which in turn powers the processing unit 209, the functional device 105, and the wireless communication interface 211.

[0086] Electromagnetic coil 207 is operable to detect the pose of wireless interactive toy building element 100 relative to another wireless interactive toy building element. For this purpose, wireless interactive toy building element 100 can be configured to use electromagnetic coil 207 to measure components of one or more magnetic fields (along one or more directions, including relative phase) generated by a corresponding coil of another wireless interactive toy building element in the system. In this way, based on the measurement of electromagnetic coil 207, the wireless interactive toy building element can detect its own relative pose to another wireless interactive toy building element. Furthermore, by monitoring the pose over time, the wireless interactive toy building element can detect whether it is moving or stationary relative to each other. In this way, the wireless interactive toy building element can determine which other wireless interactive toy building elements are interconnected within a coherent toy building model. The wireless interactive toy building element can also be configured to excite one or more electromagnetic coils to allow one or more other wireless interactive toy building elements to measure the one or more magnetic fields thus generated and to perform corresponding pose determination based on these measurements.

[0087] One or more functional devices 105 may include a light source (e.g., an LED), a speaker, a motor, and / or another functional device operable to perform a user-perceived function.

[0088] One or more sensors 108 may include light sensors, sound sensors, rotary encoders, accelerometers, gyroscopes and / or any other suitable sensors, such as those used in combination. Figure 1 As mentioned above.

[0089] The wireless communication interface 211 may include a radio frequency transceiver and an associated antenna. In some embodiments, the wireless communication interface may include a Bluetooth chip or circuitry, or another form of radio frequency transceiver adapted for communication via a wireless communication network, such as using known low-power, short-range wireless network technologies, such as Bluetooth / Bluetooth Low Energy, ZigBee, Z-Wave, or similar wireless technologies for low-power personal area data networks conforming to standardized protocols. The wireless communication interface 211 is operable for bidirectional communication with other wireless interactive toy building elements of the system. Thus, the wireless interactive toy building elements are operable to transmit their identification and / or operational attributes, calibration parameters, scheduling information, pose information, etc.

[0090] Processing unit 209 may include one or more microcontrollers, one or more microprocessors, one or more ASICs, and / or one or more other suitable processing units or combinations thereof. Processing unit 209 may be configured to control the functional behavior of wireless interactive toy building elements. Wireless interactive toy building elements may be configured with (e.g., pre-programmed) default behaviors, such as having default executable instructions stored in the memory of the wireless interactive toy building element and executable by the processing unit of the wireless interactive toy building element. The default executable instructions may define a predetermined set of rules for responding to external stimuli sensed by the sensor system, particularly for responding to detected poses relative to other wireless interactive toy building elements or to detected changes in such poses. In some embodiments, the behavior of the wireless interactive toy building element may be programmed or configured by a user, for example, by receiving program data and / or configuration parameters. For this purpose, the wireless interactive toy building element may receive program and / or control data and / or configuration parameters from a computer or from another external electronic device (e.g., directly or via another toy module of the system). External electronic devices may be, for example, desktop computers, tablet computers, smartphones, laptop computers, or other programmable computing devices. Alternatively or additionally, wireless interactive toy building elements can capture program and / or control data and / or configuration parameters from wireless tags (e.g., from RFID tags) or from other data storage devices. For example, wireless interactive toy building elements can be operated to read such wireless tags or other data storage devices in a contactless manner as described herein.

[0091] Figure 3 Two wireless interactive toy building blocks, 300A and 300B, are shown respectively, for example. Figure 1 and Figure 2The wireless interactive toy building elements are of the type shown. Wireless interactive toy building elements 300A and 300B may include functional devices of the same type or different types. Wireless interactive toy building element 300A is operable to detect the pose of wireless interactive toy building element 300A relative to the internal coordinate system of wireless interactive toy building element 300B. The relative position can be defined as the three-dimensional displacement 312 of the internal coordinate system 311A ​​of wireless interactive toy building element 300A relative to the internal coordinate system 311B of wireless interactive toy building element 300B. The relative orientation can be defined in different ways, such as by quaternions or by defining three angles of rotation of the internal coordinate system 311A ​​of wireless interactive toy building element 300A relative to the internal coordinate system 311B of wireless interactive toy building element 300B, or in other ways. Thus, these angles can respectively describe the pitch angle, yaw angle, and roll angle of element 300A relative to element 300B. Similarly, wireless interactive toy building element 300B can detect its own corresponding pose relative to element 300A.

[0092] One or both of the wireless interactive toy building elements 300A and 300B are operable at a predetermined time to activate one or more of their electromagnetic coils to emit one or more magnetic fields. When the wireless interactive toy building element 300B emits a magnetic field, the wireless interactive toy building element 300A can use its corresponding electromagnetic coil to receive and sense the emitted magnetic field and perform a magnetic field measurement. Based on the measurement of the emitted magnetic field, the receiving wireless interactive toy building element 300A can calculate its own pose relative to the wireless interactive toy building element 300B that is currently generating the magnetic field, as described herein. Although Figure 3 Only two wireless interactive toy building elements are shown, but it should be understood that the system may include more than two wireless interactive toy building elements. When one of the wireless interactive toy building elements emits a magnetic field, the other wireless interactive toy building elements can use their respective electromagnetic coils to receive and sense the emitted magnetic field and perform corresponding magnetic field measurements and pose determinations.

[0093] It should be understood that three-dimensional positioning may require each wireless interactive toy element to include three coils, which are preferably arranged orthogonally to each other.

[0094] The wireless interactive toy building elements 300A-300B are also operable to communicate with each other via a wireless communication network, for example, by broadcasting messages to all other wireless interactive toy building elements in the system or otherwise. When the wireless interactive toy building elements are operable to communicate with each other, they can share a timing schedule that defines which wireless interactive toy building elements should emit magnetic fields and when. The wireless interactive toy building elements can also exchange information about their identification and / or the type of functional devices they include and / or about their corresponding operating status, calibration parameters, measurements they expect to perform, etc.

[0095] Wireless interactive toy building elements can broadcast their determined poses to other wireless interactive toy building elements via a wireless communication network, including those currently emitting magnetic fields. The role of an emitting wireless interactive toy building element (i.e., the role of a wireless interactive toy building element currently emitting one or more magnetic fields) can be selectively assigned to a corresponding wireless interactive toy building element, for example, cyclically or according to another timing schedule, or otherwise. The timing schedule can be created by a selected wireless interactive toy building element (also referred to as a scheduler device). The scheduler device can broadcast the created timing schedule to other wireless interactive toy building elements, or otherwise share the created timing schedule with other wireless interactive toy building elements. Therefore, after multiple wireless interactive toy building elements have generated their respective magnetic fields, the wireless interactive toy building elements can obtain some (if not all) distances and optionally even orientation and / or orientation pose information relative to other wireless interactive toy building elements in the system.

[0096] The resulting pose information can be used by the wireless interactive toy building elements in a variety of ways. For example, based on their relative distance and orientation, wireless interactive toy building element 300A can determine whether it is physically connected to wireless interactive toy building element 300B, for example, as part of the same coherent toy building model—or at least whether they could be so interconnected. To this end, wireless interactive toy building element 300A can determine whether the measured pose conforms to the constraints imposed by the toy building system. Alternatively or additionally, the wireless interactive toy building elements can monitor relative poses over a period of time. If the relative poses remain constant, the wireless interactive toy building elements can determine that these elements are indeed physically interconnected.

[0097] Specifically, the wireless interactive toy building element 300A can monitor its pose relative to element 300B during the period when the wireless interactive toy building element 300A detects a change in its own motion (e.g., using the IMU or accelerometer of the wireless interactive toy building element). If the relative pose between elements 300A and 300B remains unchanged during such detected motion, one or each of these elements can determine that it is physically interconnected with the corresponding other element.

[0098] Alternatively or additionally, one or two of the building elements of a wireless interactive toy may enable the gaming experience based at least in part on detected poses, such as based on detected proximity, detected relative movement, orientation, etc.

[0099] Figure 4 An exploded view of an example of an electronic device in the form of a wireless interactive toy building element is shown, generally designated 100. The wireless interactive toy building element 100 is similar to... Figure 1 and Figure 2 One embodiment includes a housing, a processing unit, and one or more electromagnetic coils, all housed within the housing. As will be described below, the wireless interactive toy building element 100 also includes additional sensors and functional devices, a rechargeable battery 210 (or other rechargeable power source), and a wireless communication interface 211, all as described in conjunction with one or more previous embodiments.

[0100] exist Figure 4 In the example, the housing of the wireless interactive toy building element 100 includes an upwardly opening bottom housing member 101A and a cover member 101B. The cover member 101B is configured to connect to the bottom housing member 101A and, when connected, close the opening of the bottom housing member, such that the bottom housing member and the cover member together form a housing that accommodates the remaining components of the wireless interactive toy building element. The cover member can be fastened to the bottom housing member in any suitable manner, such as by snap-fit ​​connection, welding, gluing, or other methods.

[0101] In some embodiments, the bottom housing member 101A and the cover member 101B are made of a plastic material (e.g., a thermoplastic polymer) or another suitable material. The housing may be made, for example, by injection molding or another suitable manufacturing process. In this example, the cover member is made of a transparent material.

[0102] The shell is as follows: Figure 1 The box-shaped cover member has a top surface including connecting protrusions 104, and the bottom surface of the bottom shell member includes a corresponding cavity. Figure 4 (not shown in the image), also as in combination Figure 1 As stated above.

[0103] The wireless interactive toy building element 100 includes a rechargeable battery 210 (or other rechargeable power source) housed in a bottom housing member 101A.

[0104] The wireless interactive toy building block 100 includes a support frame 420, a printed circuit board (PCB) 430, and three pairs of electromagnetic coils 207X, 207Y, and 207Z. The PCB 430 is attached to the support frame 420, and the coils are wound around the frame 420, such that the support frame, coils, and PCB form a core component 42 housed inside the bottom housing member 101A.

[0105] The wireless interactive toy building block 100 also includes an antenna 413 and a speaker 415, both mounted to a cover member 101B to form a top assembly 41. The top assembly 41 also includes a colored insert 412 sandwiched between the cover member 101B and the antenna 413. The top assembly 41 also includes an opaque insert 414 sandwiched between the antenna 413 and the speaker 415. Inserts 412 and 414 provide sound holes to allow high-frequency sound from the speaker to pass through, while obscuring the antenna and other electronic components, making them invisible through the transparent cover member 101B.

[0106] PCB 430 is electrically connected to antenna 413, speaker 415, rechargeable battery 210, and coils of coil pairs 207X, 207Y, and 207Z. PCB 430 also includes several electronic components. Specifically, PCB includes processing unit 209, LEDs 431A and 431B, side-emitting LED 438, microphone 432, coil interface circuitry 433, memory 435, accelerometer 436, and wireless communication circuitry 437. The top assembly also includes an acoustic seal 416 positioned on top of microphone 432.

[0107] Processing unit 209 can be implemented as a single processing unit or a combination of multiple components, such as an ASIC and a microprocessor, or otherwise. Processing unit 209 is coupled to the coils of coil pairs 207X, 207Y, and 207Z via coil interface circuitry 433. Coil interface circuitry 433 can be implemented as a single unit or multiple components. At least a portion of the coil interface circuitry can be implemented by an ASIC, for example, an ASIC that also implements a portion of processing unit 209. Processing unit 209 is also coupled to the remaining electronic components and implements suitable drivers and / or other control functions for operating the respective electronic components. Wireless communication circuitry 437 is coupled to antenna 413 and processing unit 209 for implementing a suitable wireless communication protocol, such as Bluetooth Low Energy (BLE) based or otherwise. Figure 4 As schematically shown, communication circuitry 437 or at least a portion thereof may be integrated with processing unit 209.

[0108] LEDs 431A and 431B are arranged at their respective ends of the PCB, such that light from the LEDs is visible through the transparent cover member 101B. A side-emitting LED 438 is arranged at one end of the PCB, such that light from the side-emitting LED is output through the side portion 1011 of the transparent cover member 101B.

[0109] As will be described in more detail below, the electromagnetic coils are arranged as three pairs of corresponding coils 207X, 207Y, and 207Z, such that each pair of coils is arranged coaxially with each other and orthogonal to the other pairs of coils. Specifically, coil pair 207X includes coils 207XA and 207XB, coil pair 207Y includes coils 207YA and 207YB, and coil pair 207Z includes coils 207ZA and 207ZB. The coils of each pair are arranged spaced apart from each other, close to the corresponding sides of the box-shaped housing. The coils of each pair are electrically connected in series with each other, specifically such that they are cumulatively coupled.

[0110] Figure 5 A schematic diagram of an embodiment of an electronic device is shown. This electronic device (generally designated 100) can be a wireless interactive toy building block, for example, combined with... Figure 1 , Figure 2 or Figure 4 Any of the above. Alternatively, the electronic device may be of a different type of electronic device.

[0111] Electronic device 100 includes one or more electromagnetic coils for measuring at least one magnetic field generated by an electromagnetic coil of another electronic device. Figure 5 In the example, the electronic device includes three pairs of electromagnetic coils 207X, 207Y, and 207Z, each pair comprising two coils connected in series. Specifically, one pair of coils 207X includes coils 207XA and 207XB, another pair of coils 207Y includes coils 207YA and 207YB, and the third pair of coils 207Z includes coils 207ZA and 207ZB.

[0112] The electronic device 100 also includes a processing unit 209 for calculating the pose of the electronic device relative to the other electronic device.

[0113] Each pair of electromagnetic coils is configured to measure the gradient information of the measured magnetic field, and the processing unit is configured to calculate the pose based on the measured magnetic field and the measured gradient information.

[0114] Therefore, two measurement nodes are defined at the corresponding positions along the series-connected coil pairs for each pair of electromagnetic coils. Figure 5In this configuration, one measurement node of each coil pair is labeled 501X, 501Y, and 501Z, respectively, while the other measurement node of each coil pair is labeled 502X, 502Y, and 502Z, respectively. Specifically, measurement nodes 501X, 501Y, and 501Z are arranged at one end of the respective coil pair. Additional measurement nodes 502X, 502Y, and 502Z are also defined at the center between the two coils of each coil pair. The electronic device 100 includes a magnetic field measurement circuit 4332, configured to measure the electrical signal at the corresponding measurement node of each coil pair, particularly the electrical signal between each measurement node of each coil pair and a reference node and / or to ground. For this purpose, in Figure 5 In the example, nodes 503-X, 503-Y, and 503-Z can be grounded, for example, via a suitable capacitor or otherwise.

[0115] Electronic device 100 includes a coil interface circuit 433 electrically coupled to electromagnetic coil pairs 207X, 207Y, and 207Z, and electrically coupled to a processing unit 209. The coil interface circuit 433 includes a magnetic field measurement circuit 4332 and a magnetic field generation circuit 4331. Although in Figure 5 While shown as separate blocks, it should be understood that the coil interface circuitry and processing unit may be partially or completely integrated with each other. For example, a portion of the magnetic field measurement circuitry 4332 and / or the magnetic field generation circuitry 4331 may be implemented by the processing unit 209, or otherwise.

[0116] The magnetic field generating circuit 4331 can be configured to apply transmission signals to the measurement nodes 501X, 501Y, and 501Z of one or more electromagnetic coil pairs, respectively, so that the corresponding one or more coils generate magnetic fields that can be measured by another electronic device. Specifically, the processing unit 209 can selectively operate the electronic device in either a transmission mode or a reception mode. When operating in transmission mode, the electronic device can control the electromagnetic coils to generate one or more magnetic fields, allowing other electronic devices to perform magnetic field measurements. When operating in reception mode, the electronic device can measure electrical signals (e.g., voltage) at the corresponding measurement nodes of each coil pair, in order to perform a magnetic field measurement of at least one magnetic field generated by another electronic device.

[0117] Specifically, when operating in transmit mode, the electronic device can activate one pair of electromagnetic coils at a time and sequentially activate each pair in turn to transmit magnetic fields, particularly a series of different magnetic fields. When operating in receive mode, the electronic device can simultaneously or sequentially probe its electromagnetic coil pairs to measure the magnetic field components along the corresponding directions. A possible timing sequence of the transmit and measurement cycles will be combined... Figure 6 Describe it.

[0118] Figure 6 The magnetic timing sequence is illustrated schematically. Specifically, Figure 6 The upper portion illustrates an example of a transmission sequence for a transmitter electronics device (particularly an electronics device operating in transmission mode). The transmitter electronics device generates a magnetic field during transmission cycle 200. During the transmission cycle, the transmitter electronics device activates one electromagnetic coil (or coil pair) at a time, sequentially. For example, during the initial transmission time slot 101, the transmitter electronics device may activate its electromagnetic coil pair 207X. During the subsequent transmission time slot 102, the transmitter electronics device may activate its electromagnetic coil pair 207Y. During the third transmission time slot 103, the transmitter electronics device may activate its electromagnetic coil pair 207Z. However, it should be understood that the transmitter electronics device may activate its electromagnetic coils in a different order.

[0119] Figure 6 The lower part illustrates an example of a receiving sequence for a receiver electronics device (particularly an electronics device operating in receive mode). The receiver electronics device synchronizes its measurements with the transmission cycle of the transmitter electronics device. To do this, the electronics devices can use wireless communication via a wireless communication network to synchronize the magnetic field measurements. For example, the electronics devices can establish a shared timing schedule that defines which electronics device operates in transmit mode and when, and / or they can synchronize their respective clocks.

[0120] A shared timing schedule can be used cyclically, for example, until a new shared timing schedule has been created and distributed to the electronic device. Alternatively, a new timing schedule can be created and distributed so that the electronic device uses the new timing schedule whenever the current timing schedule is complete. Creating new timing schedules allows the system to adapt the timing schedule to new situations, such as adapting to electronic devices being turned off or otherwise leaving the wireless communication network, adapting to new electronic devices joining the wireless communication network, or adapting to changes in the required pose sensing operation rate of one or more electronic devices. For the purpose of executing the timing schedule, the electronic device can execute appropriate synchronization schemes, such as using broadcast signals from the wireless communication network. The shared timing schedule allocates reserved time intervals for each corresponding operation.

[0121] A shared timing schedule is used to reserve pose sensing time, and for each reserved pose sensing time, the transmitter role is assigned to the corresponding electronic device. Figure 6The upper portion illustrates one of these reserved pose sensing times. During the reserved pose sensing time, the electronic device designated as the transmitter electronics emits a series of magnetic fields to allow the remaining electronic devices to operate as receiver electronics and perform their respective pose sensing operations relative to the pose of the currently transmitting electronic device. Therefore, the pose sensing time is reserved for cooperative magnetosensing operations, i.e., magnetosensing operations involving the synchronous and concurrent operation of more than one (particularly all) electronic devices in the system. Thus, the time reserved for cooperative sensing operations is used to synchronize these operations and assign different roles, particularly transmitter roles and optionally receiver roles, to the respective electronic devices. In some embodiments, the duration of the pose sensing time can be selected to be long enough to allow the receiver electronic device to perform magnetic field measurements. In some embodiments, the duration of the pose sensing time is from 5 ms to 20 ms, for example, about 10 ms. The pose sensing times can be grouped such that they are allocated into a series of consecutive time intervals during which the corresponding electronic device is designated as the transmitter electronics, in order to allow different electronic devices to act as transmitter electronics and to allow for improved overall determination of the spatial configuration of the electronic devices. Pose sensing times or their groupings can be spaced sufficiently to allow for the allocation of reserved time between them for independent sensing operations, particularly tag sensing operations.

[0122] It should be further understood that a shared timing schedule may include alternative or additional times, such as those used for alternative or additional operations. It should also be understood that a shared timing schedule can be created in various ways, such as as a static timing schedule or dynamically, such as adaptively based on specific circumstances.

[0123] In any case, during each of the transmission time slots 101, 102, and 103, the receiver electronics can perform magnetic field measurements using each of its electromagnetic coils. For example, during transmission time slot 101, the receiver electronics can initially measure the magnetic field using one of its coils or coil pairs (e.g., coil pair 207X) during reception time slot 301, then use another coil or coil pair (e.g., coil pair 207Y) during reception time slot 302, and finally use a third coil or coil pair (e.g., coil pair 207Z) during reception time slot 303. Similarly, it should be understood that the receiver electronics can perform measurements in a different order. During each subsequent transmission time slot 102 and 103, the receiver electronics can again cycle through its coils or coil pairs and perform the corresponding measurements. Therefore, the duration 200 of the entire measurement cycle is at least three times the duration 100 of the transmission time slot. Thus, the duration 300 of each reception time slot is approximately one-third of the duration 100 of the transmission time slot. Optionally, the receive time slot is slightly shorter than one-third the duration of the transmit time slot to allow for a buffer period to account for possible desynchronization or clock drift between the transmitter electronics and the receiver electronics.

[0124] During each receive time slot, the receiver electronics can acquire signals at the corresponding measurement nodes, as will be described in more detail below. Therefore, for each of the three electromagnetic coils of the transmitter electronics, the receiver electronics performs a field measurement using each of its own electromagnetic coils. During each field measurement for a given transmit coil or transmit coil pair, and for a given receive coil or receive coil pair, the receiver electronics can measure the signal at the corresponding end nodes 501X, 501Y, or 501Z of the receive coil or coil pair, and can also measure the signal at the center node 502X, 502Y, or 502Z of the receive coil or coil pair. Each signal measurement involves the measurement of signal amplitude and phase. Preferably, for each receive coil or coil pair, the measurements at the end nodes 501X, 501Y, and 501Z are performed simultaneously with the measurements at the corresponding center nodes 502X, 502Y, and 502Z, respectively, to obtain a more accurate phase determination. It should be understood that the receiver electronics can perform each signal measurement multiple times to improve the overall signal-to-noise ratio.

[0125] The receiver electronics can then determine its relative position and orientation with respect to the transmitting electronics based on the signal obtained therefrom.

[0126] Figure 7 A schematic flowchart illustrating an example of a pose measurement process is shown. This process can be performed by the processing unit of the receiver electronics.

[0127] In the initial step S1, the process performs field estimation of the measured magnetic field components along the coil axes of each coil or coil pair. To this end, the process performs phase-coherent field measurements to estimate the corresponding field measurement values. For each transmitting coil or coil pair and for each measurement node of each receiving coil or coil pair, the measurement process generates multiple (e.g., 2 to 20) complex measurements. For each transmitting coil or coil pair and for each measurement node of each receiving coil or coil pair, the process processes these signal measurements to produce: amplitude estimation, phase estimation, and optionally, an estimate of the frequency drift between the local oscillators of the receiving electronics and the transmitting electronics.

[0128] To this end, for each transmitting coil or coil pair and for each measurement node of each receiving coil or coil pair, the process may first combine multiple measurements into one. Then, the process may perform derotation in the complex plane and time alignment of the measurements by utilizing an estimate of the frequency error between the transmitter electronics and receiver electronics to obtain an estimate of the magnitude and phase of the magnetic field. The process may optionally adjust the estimated magnitude and / or phase for operational variations of the electronics and / or manufacturing differences between different electronics that may affect the magnetic field generation of the transmitter electronics and / or the field measurement of the receiver electronics. Examples of operational variations that can be compensated include the current operating temperature of the receiving and / or transmitting blocks, the battery voltage of the receiving and / or transmitting electronics, and / or the gain settings of the measurement circuitry. Examples of static compensation factors may include one or more device-specific calibration parameters of the transmitting and / or receiving electronics to compensate for possible differences between components used to manufacture the respective devices. Such calibration parameters may be established, for example, by performing calibration measurements during manufacturing and / or based on a suitable theoretical model. It should be understood that other embodiments may perform compensation for alternative or additional factors, or they may omit such compensation. In order to apply compensation to the runtime or static properties of the transmitter electronic device, the electronic device can exchange information about its static and / or changing properties via a wireless communication network.

[0129] In step S2, the process performs pose estimation to calculate information about the estimated position and / or orientation based on field measurements obtained from the signals at the corresponding end nodes of each coil or coil pair and / or from the signals at the midpoint node. The pose estimation can be based on any suitable pose estimation algorithm known in the art, such as the algorithm described in W. Kim, J. Song, and FCPark, “Closed Position and Orientation Estimation for Triaxial Electromagnetic Tracking Systems,” IEEE Transactions on Industrial Electronics, Vol. 65, No. 5, pp. 4331-4337, May 2018, doi:10.1109 / TIE.2017.2760244.

[0130] Pose estimation based on magnetic field measurements inherently leads to the determination of ambiguity. In particular, pose estimation yields two possible solutions, both of which are consistent with the measured magnetic field (e.g., magnetic field components, including their relative phase).

[0131] This is Figure 8 The diagram schematically illustrates a system of two electronic devices 300A-300B, for example. Figure 3 Wireless interactive toy building blocks. Electronic devices 300A-300B can be combined as follows... Figure 4 or Figure 5 The aforementioned electronic devices. Each electronic device includes three electromagnetic coils or three pairs of electromagnetic coils as described herein. Figure 8 In the example, electronic device 300A is performing pose determination relative to electronic device 300B. Therefore, electronic device 300B has emitted a corresponding magnetic field via its respective electromagnetic coil, and electronic device 300A has performed a magnetic field measurement using its electromagnetic coil and performed the pose estimation in step S2 above. The pose estimation produces two solutions: the (correct) position and orientation of device 300A relative to device 300B, and a second solution, which is determined by device 300A relative to a (dummy) device (indicated by reference numeral 301B and...). Figure 8 The pose of the electronic device 300A is shown in the figure (indicated by dashed lines). Based solely on the magnetic field components measured using three coils or coil pairs, it is impossible to determine which of the two solutions corresponds to the actual pose of the electronic device 300A.

[0132] Refer again Figure 7 And continue to refer to Figure 8 To eliminate ambiguity in pose estimation and determine an unambiguous pose, the process proceeds to step S3, where pose disambiguation is performed based on the estimation of the magnetic field gradient along the coil axis of the corresponding coil of the receiver electronics. This method is based on the understanding that two ambiguous poses of device 300A relative to device positions 300B and 301B result in different field gradients at receiver electronics 300A, meaning that gradient measurements can be used to distinguish between two possible solutions for the correct pose.

[0133] At least some embodiments disclosed herein use axially spaced coil segments of a receiving coil to perform at least the estimation of a magnetic field gradient. For this purpose, the receiver electronics 300A measures the signal at the central measurement node of its electromagnetic coil pair.

[0134] Figures 9A to 9B An example of pose disambiguation using a central measurement node that receives a pair of electromagnetic coils is shown. Figures 9A to 9B Each of them shows an electronic device (e.g. Figure 3 or Figure 8An embodiment of the electronic device 300A includes a pair of receiving coils, in this example, coil pair 207Z. As described above, coil pair 207Z includes two coils 207ZA and 207ZB, which are coaxially arranged and axially spaced apart from each other. They are coupled in series and define a measurement node 501Z at one end of coil pair 207Z, and an additional central measurement node 502Z arranged between coils 207ZA and 207ZB. The processing unit 209 of the electronic device is configured to measure a first signal at end node 501Z and a second signal at central measurement node 502Z. Figures 9A to 9B In the example, reference node 503Z is grounded via a capacitor, and the processing unit is connected to end node 501Z and center node 502Z to measure the respective signals at these points relative to ground.

[0135] As described above, in step S2, the measurement signal (e.g., the measured voltage signal) at end node 501Z is used to calculate the magnetic field components along the corresponding axes. Specifically, the measurement signal at end node 501Z indicates the sum of the induced electromotive forces on the two coils 207ZA and 207ZB. Therefore, this signal is useful for determining the magnetic field component Bz along the coil axis (the z-axis in this example). The determined magnetic field components along the corresponding axes of all three coils are used to calculate the ambiguous pose determined in step S2.

[0136] The measurement signal at center node 502Z (e.g., the measured voltage signal) is combined with the measurement signal at end node 501Z to indicate the difference in induced electromotive force between coils 207ZA and 207ZB. This is in Figure 9A and Figure 9B As shown in [the image]. Figure 9A In the middle, the induced electromotive force in the left coil 207ZA is larger, while... Figure 9B In the middle, the induced electromotive force in the right coil 207ZB is larger.

[0137] Therefore, by measuring the magnitude and phase of the voltage at the end nodes and the center node, the processing unit 209 obtains sufficient information to estimate the field component along the coil axis and the first-order spatial derivative of the field component along the coil axis, for example, in Figures 9A to 9B In the example Bz and dBz / dz .

[0138] Although the magnetic fields measured for the two ambiguous poses of device 300A are the same, the signs of the spatial derivatives are different. It should be understood that the electronic device can use other coil pairs to perform corresponding measurements for the x and y directions.

[0139] Therefore, refer to again Figure 7In step S3, for each of the two ambiguous poses of device 300A generated from the pose estimation in step S2, the process calculates the corresponding expected gradient signal. Then, the process selects the pose whose measured gradient signal best matches the calculated expected gradient signal. Preferably, measurements at end nodes 501X-Z and at the corresponding center nodes 502X-Z are performed simultaneously to obtain accurate phase comparison.

[0140] When measurements are performed using three receiving coils (or coil pairs), and when each receiving coil (or coil pair) performs a corresponding measurement for the three transmitting coils (or coil pairs) of the transmitter electronics, the process can determine a corresponding decision boundary in the complex plane for each receiving coil or each pair of receiving coils. When, for a given receiving coil (or coil pair) and a given transmitting coil (or coil pair), the measured signal lies on one side of the decision boundary, the measurement for the corresponding coil indicates one of two ambiguous poses. Conversely, when the measured signal lies on the opposite side of the decision boundary, the measurement for the coil indicates the other of the two ambiguous poses. The process can also, for example, determine a confidence value for each pair of receiving coils and transmitting coils (or coil pairs) based on the distance of the measured signal from the decision boundary.

[0141] Then, the process can calculate the cumulative / combined decision and the corresponding confidence value based on each confidence value.

[0142] In some embodiments, the electronic device may repeatedly perform magnetic field measurements, such as at regular or irregular intervals, triggered by a game event, or at the request of another electronic device. In some embodiments, the process may use information from previous magnetic field measurements to determine the current pose. To this end, pose tracking may be performed in step S4.

[0143] Pose tracking may include tracking ambiguous poses as determined in step S2 and / or tracking disambiguated poses based on decisions made in step S3.

[0144] Ambiguous pose tracking can be performed by tracking one or more pose parameters individually, or by multidimensional tracking as a combination. Pose tracking can apply one or more filters to the measured pose, thereby using past pose estimates to improve the current pose estimate. The one or more filters can include one or more of the following: a filter for the determined range, a filter for the determined orientation, and a filter for the determined orientation.

[0145] In one embodiment, the process may calculate a predicted distribution of the pose, or a predicted distribution of one or more coordinates of the pose. The calculation of this distribution may be based on the most recent prior estimate and the time elapsed since that estimate. The calculation may also be based on an assumed or previously determined estimate of the typical movement velocity relative to the pose, and / or on a determined or assumed uncertainty of the previous pose. This uncertainty may, for example, be determined based on an uncertainty estimated by a field measurement process.

[0146] An example of pose tracking is illustrated by referencing the detected range (i.e., the distance to the detected location of another electronic device). Figures 10A to 10B An example of pose tracking is shown. Specifically, Figure 10A The schematic diagram illustrates a determined distribution 901 of the most recent previous range, for example, based on the determined previous range and the corresponding estimated measurement uncertainty or confidence level.

[0147] Figure 10B The corresponding predicted distribution 902 for subsequent time steps is shown. In this example, the predicted distribution has a larger variance than the previous distribution due to the additional uncertainty caused by the time elapsed since the previous measurement. Figure 10B As shown, in addition to a larger variance, the mean of the predicted distribution may also change.

[0148] The process can also use the current range calculated in step S2 based on the current field measurement and determine the associated uncertainty. Therefore, the process can determine a current range distribution 903, for example, as a Gaussian distribution or other predetermined distribution around the current measurement range, and with a variance determined by the uncertainty associated with the current measurement range. The process can then determine a resulting range distribution 904 based on the predicted range distribution 902 and the current measured range distribution 903. It should be understood that the process can employ other filtering schemes. It should also be understood that the process can use similar or other filtering schemes for direction and / or orientation and / or the determined ambiguous state. It should be understood that the process can employ appropriate weighting between the previous estimate and the current measurement, for example, based on elapsed time and / or based on the estimated quality of the current and / or previous measurements. In some embodiments, the process implements a Kalman filter or another suitable filter.

[0149] Alternatively or additionally, the process can also perform filtering on the disambiguation state, for example... Figure 11 As shown. Therefore, this process can define a "positive" direction based on previous pose estimation (e.g., the pose closest to the previously measured pose, in...). Figure 11 (represented by a binary value + 1) and the "reverse" direction (in...) Figure 11(represented by the binary value -1). During subsequent pose estimation, this process can determine the subsequent disambiguated direction and its associated confidence value, and perform appropriate filters, such as Kalman filters, Bayesian filters, moving averages, etc., to determine the filtered disambiguated direction.

[0150] exist Figure 11 In the diagram, the disambiguated directions and associated confidence values ​​at each time point are shown as points 11, each point representing a confidence value C between +1 (corresponding to a forward direction with 100% confidence) and -1 (corresponding to a reverse direction with 100% confidence). The filtered or tracked directions are shown as lines 12. As mentioned above, it should be understood that this process can employ appropriate weighting between previous estimates and current measurements, for example, based on elapsed time and / or the quality of estimates based on current and / or previous measurements.

[0151] It should be understood that some embodiments of the pose estimation process may use alternative or additional methods to estimate the pose based on magnetic measurements.

[0152] For example, in some embodiments, the process may use additional information to perform pose disambiguation, such as information about the relative poses of other electronic devices. To this end, electronic devices may exchange information about their own relative poses via a wireless communication network, for example, by broadcasting information about their determined poses relative to one or more other electronic devices. The electronic devices can then utilize this information when performing their own pose estimation, for example, to improve pose disambiguation.

[0153] Figure 12 Examples of how electronic devices can utilize this received pose information are shown. Specifically, Figure 12 An electronic device 300A is shown, which will determine its relative pose to two other electronic devices 300B and 300C. As mentioned above, pose estimation based on the measured magnetic field components leads to ambiguous pose determination; that is, electronic device 300A, based solely on the magnetic field components, cannot determine whether the two other electronic devices are positioned at their original locations 300B and 300C or at alternative locations and orientations 301B and 301C. Electronic device 300A can use gradient measurement disambiguation to determine the correct pose, as described above. In some cases, this gradient measurement-based disambiguation may be associated with uncertainties, such as when the distance between the electronic devices is large.

[0154] However, if one of the electronic devices 300B and 300C has determined the relative position and orientation of devices 300B and 300C relative to each other, then the electronic device can transmit this information to electronic device 300A. Electronic device 300A can then use this information to perform its own disambiguation, since only one ambiguous pose is consistent with the relative poses of electronic devices 300B and 300C relative to each other. It should be understood that other scenarios and / or methods exist that can be used to reduce the number of possible ambiguous spatial configurations of multiple electronic devices when exchanging incomplete relative pose information.

[0155] Therefore, two electronic devices (e.g.) Figure 12 The disambiguated pose of electronic devices 300B and 300C can be used for one or more additional electronic devices (e.g., Figure 12 Disambiguation is performed on the relative pose measurement of the electronic device 300A.

[0156] The propagation of this disambiguation information can be used to improve the robustness of pose estimation and / or extend the effective range of disambiguated pose estimation, or enable electronic devices that do not have the ability to measure field gradients to determine their unambiguous poses.

[0157] Typically, the magnetic field used for pose measurement can be a time-varying magnetic field that changes at a suitable frequency. Many electronic devices are relatively small and have limited battery capacity. Therefore, the magnetic field used for pose estimation should preferably be relatively weak, which in turn involves the risk of interference from stray emitters, such as switch-mode power supplies and radio transmitters from consumer products.

[0158] In some embodiments, the electronic device may dynamically select the frequency of the magnetic field, for example from a set of predetermined discrete frequencies or otherwise within a predetermined frequency band, in order to reduce unintended interference.

[0159] Therefore, in some embodiments, at least one electronic device in an electronic device system can be configured to measure ambient signals at a currently selected frequency, while other electronic devices in the system (e.g., electronic devices communicating via a wireless communication network) are not performing magnetic operations within the relevant frequency range. If the electronic device performing the measurement measures an ambient signal above a predetermined threshold, the electronic device can perform the measurement at one or more alternative frequencies (e.g., each of a set of discrete predetermined candidate frequencies). The electronic device can then select the frequency at which the lowest ambient signal strength has been measured and transmit information indicating the selected frequency to other electronic devices in the system via the wireless communication network. In some embodiments, other electronic devices in the system can also report detected interference, for example, via a status message, to the electronic device assigned the frequency selection task.

[0160] The electromagnetic pose measurement embodiments disclosed herein allow for pose estimation covering six degrees of freedom (i.e., position and orientation). The pose measurement embodiments have been found to be accurate within millimeters without relying on additional sensors, such as additional coils, which would occupy space in small electronic devices and incur additional manufacturing costs. In particular, the process does not rely on expensive components such as cameras or base stations. The process is independent of specific user behaviors, such as relative movement of the electronic device or positioning the device within the line of sight of another device. The process is scalable, requires no user calibration, is robust to typical environmental disturbances, and has relatively low complexity. Furthermore, the required hardware is small enough to be adapted to electronic devices suitable for a child's hand.

[0161] Although the various aspects are described primarily with reference to toy building systems, it should be understood that they can also be implemented by other types of electronic devices.

Claims

1. An electronic device, wherein, The electronic device includes: - One or more electromagnetic coils for measuring at least one magnetic field generated by one or more electromagnetic coils of another electronic device; - A processing unit for calculating the pose of the electronic device relative to the other electronic device; At least one of the one or more electromagnetic coils is configured to measure gradient information of the at least one measured magnetic field; and the processing unit is configured to calculate the pose based on the at least one measured magnetic field and the measured gradient information.

2. The electronic device of claim 1, comprising three coils, each coil defining a coil axis, optionally the coil axes of the three coils being linearly independent.

3. The electronic device according to any one of the preceding claims, wherein, The electronic device includes a magnetic field measurement circuit configured to measure electrical signals at a corresponding measurement node along each of the one or more electromagnetic coils or along a corresponding pair of electromagnetic coils.

4. The electronic device according to any one of the preceding claims, wherein, The one or more electromagnetic coils comprise a pair of two coils, particularly two coils connected in series, wherein each of the two coils defines a corresponding coil center, and wherein the coil centers of the two coils are optionally physically spaced apart from each other, particularly physically spaced apart from each other along the direction of the coil axis of at least one of the two coils.

5. The electronic device according to any one of the preceding claims, wherein, The processing unit is configured to calculate pose information indicating two candidate poses, and select one of the candidate poses as the calculated pose based at least on the measured gradient information.

6. The electronic device according to claim 5, wherein, The processing unit is also configured to calculate a confidence value associated with the selected candidate pose.

7. The electronic device according to claim 5 or 6, wherein, The processing unit is configured to repeatedly perform pose estimation to generate a time series of the calculated pose.

8. The electronic device according to claim 7, wherein, The processing unit is further configured to calculate the current pose in the time series of the calculated pose based on the current measurement of the magnetic field and one or more previous poses in the time series of the pose.

9. The electronic device according to any one of claims 5 to 8, wherein, The processing unit includes a data storage device that stores a set of one or more device-specific calibration parameters, and wherein the processing unit is configured to calculate the pose based on the stored set of one or more device-specific calibration parameters.

10. The electronic device according to any one of the preceding claims, wherein, The electronic device is a wireless interactive toy.

11. The electronic device according to claim 10, wherein, The wireless interactive toy is or includes wireless interactive toy building elements.

12. The electronic device according to claim 11, wherein, The processing unit is configured to determine, based on a calculated time series of poses and optionally on sensor data indicating sensed motion of the wireless interactive toy building elements, whether the wireless electronic toy building elements are physically attached directly or indirectly to the other electronic device, particularly as part of a coherent structure constructed from multiple toy building elements.

13. The electronic device according to any one of the preceding claims, wherein, The electronic device includes a wireless communication interface configured to communicate wirelessly via a wireless communication network, and the electronic device is configured to communicate wirelessly with one or more other electronic devices via the wireless communication network.

14. An electromagnetic device system comprising a plurality of electronic devices, the plurality of electronic devices including at least one receiver electronic device and at least one transmitter electronic device, the receiver electronic device being an electronic device as defined in any of the preceding claims, wherein the transmitter electronic device includes one or more electromagnetic coils for generating corresponding one or more magnetic fields, wherein at least one of the electromagnetic coils of the receiver electronic device is configured to measure at least one of the one or more magnetic fields generated by the transmitter electronic device, and optionally to measure gradient information of the at least one measured magnetic field, and wherein a processing unit of the receiver electronic device is configured to calculate the pose of the receiver electronic device relative to the transmitter electronic device based on the at least one measured magnetic field and optionally based on the measured gradient information.

15. The system according to claim 14, wherein, At least a first electronic device among the plurality of electronic devices is configured to measure an ambient electromagnetic signal at a time when the at least one transmitter device does not generate a magnetic field; wherein the first electronic device includes a processing unit configured to select a target frequency based on the measured ambient electromagnetic signal and transmit the selected target frequency to the other electronic devices among the plurality of electronic devices; The transmitter electronics are configured to generate the one or more magnetic fields at the target frequency being transmitted, and the at least one receiver electronics are configured to measure the at least one magnetic field at the target frequency being transmitted.

16. The system according to claim 14 or 15, wherein, At least one first receiver electronic device is configured to: - Measure the corresponding magnetic fields generated by the first and second transmitter electronic devices among the plurality of electronic devices; - Receive disambiguated pose information about the relative poses of the first transmitter electronic device and the second transmitter electronic device with respect to each other; - Based at least on the measured magnetic field and the received disambiguated pose information, calculate the disambiguated pose of the first receiver electronic device relative to at least one of the first transmitter electronic device and the second transmitter electronic device.

17. The system according to any one of claims 14 to 16, wherein, The at least one transmitter electronic device is configured to determine at least one magnetic field, and in particular one or more field calibration values ​​for each of the generated one or more magnetic fields, and to transmit the determined one or more field calibration values ​​to the at least one receiver electronic device; and the processing unit of the at least one receiver electronic device is configured to calculate the pose of the receiver electronic device relative to the transmitter electronic device, based at least on the received one or more field calibration values.

18. The system according to any one of claims 14 to 17, wherein, The at least one receiver electronic device is configured to transmit the calculated pose of the receiver electronic device relative to the transmitter electronic device to one or more other electronic devices among the plurality of electronic devices.

19. The system according to any one of claims 14 to 18, wherein, At least one of the electronic devices is configured to create a timing schedule table and transmit the created timing schedule table to the at least one receiver electronic device and / or the at least one transmitter electronic device; The at least one transmitter electronic device is configured to temporarily generate a magnetic field according to a transmitted timing schedule; and the at least one receiver electronic device is configured to measure the generated magnetic field based on the transmitted timing schedule.

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