921results about How to "Improve ranging accuracy" patented technology

The invention relates to a generation system for a high-precision road map and belongs to the technical field of high-precision maps. The purpose is to solve the problems that the workload of producing or updating an existing high-precision map is large, and cost is high. High-precision positioning and high-precision matching are achieved relative to the existing map, existing information of the existing map is fully utilized, and the workload and cost for producing/updating of the high-precision map are lowered. The generation system is characterized in that road elements recognized through deep learning, computer vision and other methods and obtained accurate relative position information form a ground one-dimension thick and space three-dimensional sparse map similar to Mobileye, and the map can be matched and fused with an existing traffic information system GIS-T. Based on an existing low-precision electronic map, a positioning system and a vehicle-mounted camera, producing/updating of the high-precision map are achieved at a low cost. The generation system is used for producing or updating the existing high-precision road map.

A system for landing or docking a mobile platform is enabled by a flash LADAR sensor having an adaptive controller with Automatic Gain Control (AGC). Range gating in the LADAR sensor penetrates through diffuse reflectors. The LADAR sensor adapted for landing/approach comprises a system controller, pulsed laser transmitter, transmit optics, receive optics, a focal plane array of detectors, a readout integrated circuit, camera support electronics and image processor, an image analysis and bias calculation processor, and a detector array bias control circuit. The system is capable of developing a complete 3-D scene from a single point of view.

An apparatus carried by an unmanned vehicle to provide passive sensing and facilitate avoiding airborne aerial obstacles is provided. The apparatus can include at least one, but typically multiple optical systems installed, for example, in the nose of the aerial vehicle to passively sense and determine a range, direction, and velocity of the airborne obstacles to allow the aerial vehicle to avoid the airborne obstacles. The typical optical system includes at least one focal plane array or other imaging device configured to receive a wide field of view and at least one focal plane array or other imaging device configured to receive a steerable narrow field of view within the wide field of view to allow concentrated determination of the range, direction, and/or velocity of obstacles detected by the wide field of view imaging devices.

The invention discloses a vehicle-mounted millimeter-wave radar moving target recognizer. The vehicle-mounted millimeter-wave radar moving target recognizer is characterized in that the recognizer is a frequency synthesizer; a frequency agility continuous signal is modulated into a pulse signal and then is processed into a millimeter-wave signal by up-conversion; after being amplified by a power amplifier, the millimeter-wave signal is transmitted out; an antenna receives a radar echo signal back to a circulator and then the signal is transmitted into a frequency mixer; a high-frequency echo pulse and constant-amplitude high-frequency voltage generated by a high-stability local oscillator are mixed and the signal is reduced to a middle frequency and then is processed by a middle-frequency amplifier; the middle-frequency signal is directly sampled by an A/D (Analogue/Digital) conversion module; after being sampled, echo signals of a whole pulse string are stored into a storage unit; and information of targets, such as quantity, speed and direction, is measured by a signal processing unit and then is transmitted to an alarm executing unit. With the adoption of the structure, the vehicle-mounted millimeter-wave radar moving target recognizer has the advantages that 1 the distance measuring precision and the angle measuring precision of a moving target are improved; and 2 excessive hardware does not need to be added and the production cost is lower.

An electronic vertical angle sensing and indicating device for use on aiming systems is provided for bow sights and for other aiming sights for projectile launchers. Improved vertical level measurement and display minimizes the left-right drift of a projectile by sensing and indicating to the user when the projectile launcher is tilted slightly prior to release of the projectile. The vertical level indicator is easily viewed within the field of direct or near direct vision and focus of the eye in a reduced profile that does not distract the operator from the task of accurately aiming the projectile is provided. One embodiment of the present invention positions the signal indicators in the far-field of view of the eye, so that all of the signal indicators, the sighting means and the distant target being viewed are simultaneously in focus or near-focus.

The invention relates to a wireless sensor network node positioning method based on a received signal strength indicator (RSSI). The precision of the traditional method is not high, and the traditional method is easily disturbed by environment. In the method, an effective RSSI value is selected by using a Gaussian distribution function model in the aspect of reading RSSI value, so that small probability events during RSSI measurement are removed to a certain extent, and the precision of RSSI value between nodes is improved; and the coordinates of an unknown node are obtained by a triangular positioning method, and the unknown node is circularly refined via the distribution probability model of the unknown node, so that a point with the maximum distribution probability is found and is used as the final positioning coordinate. In the method, the signal intensity and distance information between anchor nodes are introduced and are used as the reference; the unknown node coordinate is found out via the distribution probability model of the unknown node; the distance measurement precision and the positioning precision between the unknown node and the anchor node are improved; and the method is not easily disturbed by environment.

The invention discloses a wavelet difference algorithm-based cable fault localization method. The method comprises the following steps of: 1, detecting a signal in real time and synchronously uploading the signal; 2, performing signal acquisition; 3, performing cable fault localization by steps of performing signal pre-treatment which comprises normalization treatment, de-noising treatment and fault signal modulus transformation, judging a wavelet packet entropy fault region, determining the fault point by selecting a one-dimensional signal, performing wavelet transformation, solving a wavelet coefficient, detecting a modulus maximum point, sorting singular points after the maximum point, performing first-order difference operation and difference comparison, and performing localization operation on the cable fault position by using a single-end fault localization method free from influence of the wave velocity; and 4, synchronously outputting the treatment result. The method has the advantages of reasonable design, simple operation, convenient implementation and high localization precision, and effectively solves the practical problems that the fault region cannot be identified and the localization precision is relatively low and easily influenced by various factors in the conventional cable fault detection method.

The invention provides a wireless and ultrasonic composite location system and a location method for the wireless and ultrasonic composite location system, wherein the wireless and ultrasonic composite location system comprises a plurality of beacon modules with fixed positions, at least one mobile location module and an electronic location platform; each of the beacon modules comprises a first wireless receiving and sending module, an ultrasonic transmitting module and a first intelligent processing module; the mobile location module is arranged on a mobile object, and comprises a second wireless receiving and sending module, an ultrasonic receiving array, an array processing module and a central processer; the electronic location platform is used for building an electronic map and sending the electronic map to the mobile location module, and is also used for coordinating the synchronization of the beacon modules and the mobile location module. The invention also comprises the location method for the wireless and ultrasonic composite location system. By adopting the system and the method, the problems of multipath effect and none-line-of-sight are solved, the measurement precision is improved, and the theoretical precision of less than 0.1mm can be reached.

The invention relates to a two-way ranging and time comparison processing terminal which is characterized in that: the processing terminal comprises a frequency benchmark, a radio frequency front end, a noise source, a frequency synthesis, a transmitting channel, a receiving channel, a medium frequency signal processor, a machine case, a display and control system, a power source distributor and a LAN switching module, wherein the configuration of the entire processing terminal is a 4U machine case postnotal plate joint interconnecting structure fastened by a standard machine cabinet; the frequency benchmark, the transmitting channel, the receiving channel, the medium frequency signal processor and the power source distributor are arranged inside a standard 4U machine case; the display and control system, which is realized through the configuration of an external notebook computer and display and control software, is in interaction with the outside through the LAN switching module. The entire processing terminal has simple equipment and high integration level; communication, ranging and time comparison are completed inside a unified channel, thereby saving frequency band resource; a pseudo code ranging system is adopted to ensure high ranging precision; moreover, the processing terminal, which has the functions of simulating dynamic state and time delay inside the transmitting channel, is used to realize the quantitative detection of the performance of a receiving terminal.

The invention relates to an indoor localization method based on clustering algorithm analytical data optimization, which is used for carrying out accurate localization on an unknown node in a complex index environment. The indoor localization method comprises the steps of: executing an RSSI (Received Signal Strength Indicator) signal processing optimization strategy, i.e., optimizing an RSSI value by using a clustering analysis Gaussian hybrid filtering model so as to eliminate the problems of dispersed intersection and serious jitter of the RSSI value, which exist due to factors of a multipath effect, a barrier and the like, and obtain one more reliable and reasonable RSSI value; adopting a fitting RSSI distance measurement model, i.e., according to an RSSI-distance conversion curve, carrying out fitting of the curve by adopting a least square method so as to obtain a logarithm path loss model suitable for a current environment; and then estimating out position information of the unknown node by using a weighted centroid localization algorithm. According to the indoor localization method disclosed by the invention, by an optimal RSSI distance measurement algorithm, accuracy of localization and distance measurement is improved, so that adaptability and localization accuracy of the localization algorithm are improved; and the indoor localization method is suitable to apply and popularize in the complex indoor environment.

The invention discloses an RSSI and TOA distance measurement based WIFI indoor positioning method. The RSSI and TOA distance measurement based WIFI indoor positioning method comprises the steps of acquiring an RSSI signal and establishing a database, adopting a positioning matching algorithm to perform data processing, adopting arrival time or colored noise elimination to perform distance measurement, establishing and rotating a planar rotating frame and performing searching, positioning and judgment. The RSSI and TOA distance measurement based WIFI indoor positioning method adopts united RSSI and TOA distance measurement to perform positioning, overcomes the defects existing when an RSSI and TOA are independently positioned and improves positioning precision and accuracy. Especially, a measurement error adapts to change of distance measurement data by establishing a target state equation and a colored noise measurement equation, and large-deviation data filtering-out effect is good. In addition, the planar rotating frame diagram established by means of the method enables the positioning process to be accurate and enables a positioning result to be high in accuracy and approximate to an actual result, and the RSSI and TOA distance measurement based WIFI indoor positioning method can be widely applied to WIFI based indoor positioning.

The invention discloses a range finding method of a pulsed laser rangefinder. The pulsed laser rangefinder comprises a pulsed laser, a photoelectric detector, an amplifier, a double-channel comparator, a time digital converter TDC and a measurement control module, wherein the photoelectric detector is connected with the amplifier; an output end of the amplifier is connected with two positive input ends of the double-channel comparator; two different discriminating threshold levels are respectively input to two positive input ends of the double-channel comparator; an output end of the double-channel comparator is connected with the time digital converter TDC; and the measurement control module is respectively connected with the time digital converter TDC and the pulsed laser; and by using the range finding method disclosed by the invention, the drift error can be reduced and the range finding accuracy can be improved.

The invention provides an optical axis nonlinear binocular range finding method. The method comprises the following steps: at first, establishing a binocular range finding device, establishing a range finding formula, which is matched with the binocular range finding device, when the optical axes of a left camera and a right camera are non-ideally parallel to each other; and calibrating the parameters of the range finding formula to obtain a rang finding formula that only comprises unknown quantities namely the imaging positions of a scene object to be measured in the left camera and right camera of the binocular range finding device. In actual application, the data of imaging positions of a scene object to be measured in the left camera and right camera of the binocular range finding device can be directly read; and then the data can be substituted into the calibrated range finding formula to calculate the distance between the scene object and a reference camera in the binocular range finding device. The provided method is suitable for the binocular stereoscopic vision device, reduces the distance measurement error caused by unparallel optical axes, and improves the ranging accuracy in actual projects.

The invention provides a combined traveling wave fault location method of a high-voltage overhead line and cable hybrid line. The method comprises the following steps of: firstly, carrying out fault section selection by using a double-ended principle according to time difference generated when a fault initial traveling wave of the hybrid line arrives at two ends, then carrying out initial fault location by using a single-ended principle, and finally working out an accurate result via the single-ended principle by combining with the time difference generated when the fault initial traveling wave arrives at two sides of the line. The method has the advantages that: the obtained fault location result is the result of the single-ended fault location principle, and the effects of hybrid line length error and accurate time synchronization problem of two sides of the line to the fault location accuracy are eliminated in the fault location by using the double-ended principle so that the accuracy and reliability of the fault location are improved. Therefore, the traveling wave fault location of the high-voltage overhead line and cable hybrid line is realized by using the method, the problem on how to accurately search a fault point position after the hybrid line is in the fault can be reliably solved and the traveling wave fault location method has a good application prospect.

A technique for geolocating (mobile) objects within an environment where other locating systems, such as GPS-based systems, may not be expected to operate successfully, uses at least three transmitter sites whose geolocations are fixed and known, and which transmit dual frequency beacons that are readily received by a mobile receiver within the environment of interest. The object's receiver processes the three sets of received signals by measuring the phase differences among respective pairs of the beacons, and then processes these phase differences to perform time difference of arrival-based or time of arrival-based distance information to locate the object relative to the beacons sites. Phase errors or offsets are readily calibrated out, to realize geolocation information at the mobile receiver.

The invention discloses a vision navigating method for a movement carrier based on the laser plane assistance. The method comprises the following steps: building a distance measurement and environment system, determining the position of a rectangular bright spot to be detected in an image, determining the center coordinate of the rectangular bright spot, obtaining a geometric distance measurement model, correcting the distance measurement model, segmenting the visual image, determining a local vectorization environmental space with distance information, positioning the position of the carrier per se, and building a global environmental space. Through the adoption of the method different from the traditional movement carrier autonomous navigation middle distance obtaining method, a laser plane is introduced as an auxiliary means, a single or a plurality of vision sensors are combined, the threadlike bright spot formed by the reflection of the laser plane on an object to be irradiated is fully utilized and taken as an cooperated distance measurement target, and the geometric relationship between the vision sensor and a laser light source is effectively utilized, so that the requirements for the precision, yield ratio and real-time performance of the distance calculating can be met. Therefore, the method is a reliable navigation method, and can be applied to a movement carrier autonomous navigation system.

A transmission line single-phase grounding fault single-end ranging method belongs to the field of power system protection and control. According to the method of the invention, positive, negative and zero sequence voltage and current phasors of a line during the time section between the occurrence of a single phase grounding fault and single phase tripping and the time section between single phase tripping and reclosing are measured at a substation protection installation site and are used as input. The initial value of fault distance is set from 0 to the overall length of the line with delta1 as the step length, and the initial value of transition resistance starts from 1 ohm and increases to 1000 ohms with 1 ohm as the step length. For each combination of the values of fault distance and transition resistance, the equivalent electromotive force values of a system at the opposite end of the line during the time section between the occurrence of the single phase grounding fault and single phase tripping and the time section after single phase tripping are respectively calculated, the sum of absolute errors of the equivalent electromotive force values is calculated, and the fault distance value corresponding to the minimum value of the sum of absolute errors is selected as the fault ranging distance. The method is high in precision, is not affected by distributed capacitive current, transition resistance, load and system impedance and has very high practical values.

Disclosed are a distance image acquisition apparatus and a distance image acquisition method capable of achieving high distance measurement accuracy and omitting wasteful imaging or calculation. The distance image acquisition apparatus (10) includes a distance image sensor (14), a drive mode setting unit (20A), a distance image generation unit (20B), a pulse light emission unit (22), and an exposure control unit (24). The exposure control unit (24) controls emission and non-emission of pulse light emitted from the pulse light emission unit (22) according to a drive mode set by the drive mode setting unit (20A), and controls exposure in the distance image sensor (14). The distance image generation unit (20B) performs calculation processing of a sensor output acquired from the distance image sensor (14) according to the drive mode set by the drive mode setting unit (20A) to generate a distance image corresponding to a distance of a subject.

The invention relates to a robot location navigation system and navigation method. The robot location navigation system comprises a plurality of beacon modules, at least one robot location terminal and an electronic navigation platform; each beacon module comprises a first wireless receiving-transmitting module, an ultrasonic transmitting module and a first intelligent processing module; each robot location terminal comprises a second wireless receiving-transmitting module, an ultrasonic receiving array, an array processing module and a central processor; the electronic navigation platform is used for storing codes of all robots, establishing an electronic map, planning and calculating a motion target or path of the robot as well a position of the beacon module and dispatching the robot to avoid a barrier and also used for coordinating the synchronism of the beacon module and the robot location terminal and receiving position coordinate data uploaded by each robot location terminal. The invention also relates to a navigation method of the robot location navigation system. By adopting the robot location navigation system and navigation method, the multi-path effect and non-line-of-sight propagation problem can be solved, the measurement precision can be improved, and automatic location is implemented.

The invention relates to a ranging method and a ranging system of femtosecond laser frequency comb synthesis wave interference. The ranging method and the ranging system of the femtosecond laser frequency comb synthesis wave interference comprises a femtosecond laser frequency comb, a Michelson interference system and the like. The light emitted by the femtosecond laser frequency comb enters a first spectroscope, transmission light through the first spectroscope is emitted to a first reflecting mirror, and reflected light returns to the first spectroscope through the first reflecting mirror. The emitted light is emitted to a second spectroscope through the first spectroscope, reflected light through the second spectroscope is emitted to a second reflecting mirror through a first single wavelength generating and frequency shifting light path, and the reflected light through the second reflecting mirror and the first single wavelength generating and frequency shifting light path returns to the second spectroscope. The emitted light through the second reflecting mirror is emitted to a third reflecting mirror through a second single wavelength generating and frequency shifting light path, and reflected light through the third reflecting mirror returns to the second spectroscope through the second single wavelength generating and frequency shifting light path. The reflected light through the second reflecting mirror and the reflected light through the third reflecting mirror are combined on the position of the second spectroscope, and are combined with light pulses of a gage beam, the interference signals of two wavelengths are divided through a diffraction grating and are respectively detected and received by two photoelectric detectors, and range measurement is completed.

The invention discloses a ranging device based on a laser phase method, and the ranging device provided by the invention comprises a laser emitting and electro-optical modulating module, an internal-external optical path module, and a photoelectric detecting and data processing module, wherein the laser emitting and electro-optical modulating module is used for emitting an infrared laser subjected to high frequency modulation, the internal-external optical path module comprises an internal optical path and an external optical path; the infrared laser is transmitted to the photoelectric detecting and signal processing module respectively through the internal optical path and the external optical path; the photoelectric detecting and signal processing module is used for respectively performing the conversion and frequency-conversion process on the two transmitted optical signals to obtain a phase difference between two optical signals so as to obtain a to-be-measured distance value. Thedevice directly transmits the light emitted by the laser to an integrated electro-optical modulator through an optical fiber; an exit beam is transmitted to the focus point of a range finder emittinglens through the optical fiber so as to greatly simplify the optical path structure; and meanwhile, the modulation frequency of the integrated electro-optical modulator is much higher than the directmodulation frequency of the laser, thereby achieving higher measurement precision.

The invention relates to a method for measuring fault location of a HVDC transmission line under consideration of measured wave velocity; the method is characterized by comprising the following steps: considering the variation characteristic of the wave velocity on the basis of the traditional dual-end location measuring method, and performing the calibration of a wave tip and the determination of the wave velocity in the same process; respectively acquiring the positive and negative data of the voltage of the HVDC transmission line by means of devices at two ends of the line; after the data is subjected to filtering processing and line-mode conversion, analyzing the obtained line-mode traveling wave, obtaining a time-frequency oscillogram of signals and determining the arrival time of the fault traveling wave to two ends of the line as well as a corresponding instantaneous frequency value; obtaining the corresponding line-mode wave velocity by using frequency-wave velocity curves; and finally, obtaining the fault distance by means of a dual-end distance measurement formula.