25results about How to "Improve angle measurement accuracy" patented technology

The invention discloses a UWB-based three-dimensional positioning method for tunnel safety monitoring, and the method comprises the steps: arranging an antenna array composed of a plurality of pairs of antennas on an anchor node, only needing one time of DS-TWR communication, enabling a to-be-measured node to be a distance measurement initiator, transmitting a distance measurement request frame according to a set period, enabling the anchor node to be a distance measurement responder, and enabling the distance measurement request frame to be transmitted according to a set period in the antenna array; a certain antenna which firstly receives the request frame serves as a response antenna, the other antennas serve as non-response antennas, and the anchor node calculates the distance between each antenna and the node to be tested according to the difference value of the receiving timestamps of the node to be tested, the response antenna and the non-response antenna; and based on the distance and the PDOA data, obtaining the coordinates of the to-be-measured node subjected to coarse positioning and the coordinates of a plurality of candidate to-be-measured nodes subjected to fine positioning, and screening the node with the minimum distance to the coordinates of the to-be-measured node subjected to coarse positioning from the plurality of candidate to-be-measured node coordinates as a final positioning result of the to-be-measured node. According to the invention, accurate positioning requirements in scenes such as subway tunnels and the like can be effectively met.

The invention discloses a spacecraft executing mechanism fault diagnosis and online calibration device and method based on double sensors, and belongs to the technical field of aircraft control and ground simulation. In order to carry out detection and off-line compensation on errors, the device comprises an absolute grating encoder, an actuating mechanism expansion shaft, an inductosyn, a control moment gyroscope, a photoelectric reading head and a signal amplification circuit, the absolute grating encoder, the inductosyn and the control moment gyroscope are coaxially installed through the executing mechanism expansion shaft, one end of the executing mechanism expansion shaft is connected with the absolute grating encoder, the other end of the executing mechanism expansion shaft is connected with the inductosyn, and the inductosyn is connected with the control moment gyroscope. The absolute grating encoder is connected with a first processing circuit box through a photoelectric reading head wire, and the first processing circuit box is connected with an upper computer. The inductosyn is connected with the signal amplification circuit and the excitation power supply through wires, the signal amplification circuit is connected with the second processing circuit box through a wire, and the second processing circuit box is connected with the upper computer.

The invention relates to the technical field of laser quantum interference measurement, in particular to a three-degree-of-freedom angle measurement device and method based on radial polarized light, which can realize high-precision simultaneous measurement of three-degree-of-freedom tiny angles by utilizing the characteristics of the radial polarized light and combining an advanced optical system and a signal processing technology. By adopting an auto-collimation technology principle, the tight focusing characteristic of radial polarized light and the light splitting characteristic of a Wollaston prism are combined, so that technical indexes such as angle measurement resolution and angle measurement precision can be effectively improved; the roll angle measuring system formed by using the focusing characteristic of the all-dielectric super-lens array and the CCD camera can greatly improve the roll angle measuring precision of the existing method.

The invention relates to the technical field of precision reducer testing, and discloses an angle measurement error suppression system and method in a precision reducer dynamic test, and the system comprises a servo motor closed-loop regulation and control module, a measurement shafting motion state monitoring module, a piezoelectric ceramic driver regulation and control module, and a combined control module. The method comprises the steps that first-step regulation and control are conducted through the servo motor closed-loop regulation and control module, second-step regulation and control are conducted through the piezoelectric ceramic driver regulation and control module, and according to the running states, monitored in real time, of the high-speed-end motor and the low-speed-end motor and the motion state, monitored in real time, of the measuring shaft system, and in combination with a preset standard, the high-speed-end motor and the low-speed- The control proportion of the closed-loop regulation and control module of the servo motor and the piezoelectric ceramic driver regulation and control module is dynamically adjusted, so that the dynamic angle measurement error is kept within the preset range, and the angle measurement error caused by the dynamic change of the system structure in the speed reducer testing process can be effectively reduced.

The invention discloses a digital baseband processing method and device for a very high frequency omnidirectional beacon signal and a receiver, and relates to the technical field of signal processing, and the technical scheme is characterized in that the method comprises the following steps: carrying out AM demodulation on a VOR baseband signal to obtain a VOR envelope signal; processing the VOR envelope signal through band-pass filters BPF1, BPF2 and BPF3 to obtain a variable phase signal, a first reference phase signal, Morse code audio and air-ground communication voice; performing FM demodulation on the first reference phase signal to obtain a second reference phase signal; and carrying out amplitude normalization on the variable phase signal and the second reference phase signal, then carrying out Ref-Var phase discrimination to obtain a phase difference between the two signals, and converting the phase difference into an azimuth angle of the aircraft. By adopting the digital design, the use of analog devices is reduced, the system integration level is increased, higher angle measurement precision can be obtained, and the navigation performance required by civil aviation area navigation can be better met.

The invention relates to radar angle measurement, in particular to an anti-multipath radar angle measurement system and method based on comprehensive angle measurement, and the method comprises the steps: an angle measurement fusion module generates multi-source pitch angle candidate data through sum-difference angle measurement and sum-sum angle measurement; the track batch optimization module is used for performing batch processing on the multi-source pitch angle candidate data of the multiple trace points in a track batch stage, selecting an optimal pitch angle and updating the three-dimensional coordinates of each trace point; the track association optimization module is used for calculating the Euclidean distance between the three-dimensional coordinate corresponding to the multi-source pitch angle candidate data of each trace point and the historical track in the track tracking stage, selecting the optimal pitch angle and updating the three-dimensional coordinate of each trace point; the flight path smoothing processing module is used for smoothing the flight path height sequence and outputting the smoothed flight path height sequence so as to reduce noise interference and improve height estimation stability; the technical scheme provided by the invention can effectively overcome the defects that multipath interference is difficult to suppress effectively, the angle measurement precision is low and the track starting stability is poor.

The invention discloses an ineffective potential suppression structure for a small inductosyn, and belongs to the technical field of inductosyn. The invention aims at the application requirements of high precision and small size of the inductosyn. A stator effective conductor of the inductosyn is arranged on the front surface of the stator substrate and is arranged along the whole circumference of the stator substrate; a stator substrate and a rotor substrate of the inductosyn are made of ferromagnetic materials. Stator ineffective conductors of the inductosyn are arranged on the back face of a stator substrate and are arranged along the whole circumference. The stator non-effective conductor and the stator effective conductor are connected through dense via holes; a stator effective conductor and a rotor conductor of the inductosyn are arranged in a radial alignment manner. According to the stator design scheme based on the double-layer metal-based MCPCB, the ferromagnetic material is used for improving the signal strength and shielding the ineffective potential, the precision and the signal-to-noise ratio are improved, meanwhile, the radial and axial space occupation is reduced, and the application requirement of the induction synchronizer in a small precise servo system is met.

The present invention discloses a three-dimensional positioning method based on UWB for tunnel safety monitoring. An antenna array consisting of multiple pairs of antennas is set on an anchor node. Only one DS-TWR communication is required. The node to be measured is a ranging initiator, and a ranging request frame is sent according to a set period. The anchor node is a ranging responder. In the antenna array, an antenna that first receives the request frame is used as a response antenna, and the remaining antennas are non-response antennas. The anchor node calculates the distance between each antenna and the node to be measured according to the difference in receiving timestamps of the node to be measured, the response antenna, and the non-response antenna. The coordinates of the node to be measured for rough positioning and the coordinates of multiple candidate nodes to be measured for precise positioning are obtained based on the distance and PDOA data. The coordinates of the node to be measured with the smallest distance from the coordinates of the node to be measured for rough positioning are selected from the multiple candidate node coordinates for the node to be measured as the final positioning result of the node to be measured. The present invention can effectively meet the demand for precise positioning in scenes such as subway tunnels.

The invention discloses an artificial neural network monopulse angle measurement method and an artificial neural network monopulse angle measurement system applied to a feed source mismatched antenna, and solves the problems that for a five-horn monopulse antenna with a feed source mismatched, an existing monopulse angle measurement method with independent orientation and pitching can introduce extra errors, and error factors between orientation and pitch can generate coupling, so that the angle measurement accuracy is poor. And the accuracy of an angle measurement result is seriously influenced. In order to solve the problem of angle measurement of a five-horn monopulse antenna with a mismatched feed source, a nonlinear mapping relation between a complex ratio of a pitch difference signal, an azimuth difference signal and a sum channel signal of the antenna and a pitch angle and an azimuth angle under the condition of feed source mismatch is established through an artificial neural network, and a high-precision angle measurement result is obtained.

This invention discloses a passive RFID tilt detection method based on a transceiver separation architecture, comprising the following steps: acquiring a continuous wave radio frequency signal from an RF exciter; collecting a mixed signal containing a passive tag reflected wave and an RF exciter leakage wave, and simultaneously acquiring a self-interference reference signal; performing self-interference cancellation processing on the mixed signal based on the self-interference reference signal, and extracting the tag backscattered signal; when a dual-tag array is used, measuring the phase of the passive tag array separately and calculating the phase difference, calculating the initial tilt angle of the target object, and obtaining the final tilt angle after correction; when a single passive tag is used, extracting the phase data of the single passive tag and performing linear interpolation, and substituting the interpolated real-time phase into a linear model to calculate the tilt angle. This invention can effectively eliminate transceiver self-interference and automatically offset the influence of distance changes on angle measurement accuracy, significantly improving the robustness and accuracy of object tilt detection.

The present invention discloses an anti-destruction warning system, method, device, storage medium and product. The system includes a first radar, a second radar, a third radar and a central processor. The first radar and the second radar are located on the same vertical line, and the second radar and the third radar are located on the same horizontal line. Each radar radiates electromagnetic wave signals outward at the same time under the control of the central processor. The central processor judges twice whether the target enters the protection area of ​​the overhead transmission line according to the original ADC data fed back by each radar. The first radar and the second radar are combined, and the second radar and the third radar are combined to perform the second judgment. The first radar and the second radar of the invention form an equivalent large receiving aperture elevation antenna array, and the second radar and the third radar form an equivalent large receiving aperture horizontal antenna array. While solving the angle measurement ambiguity problem, the radar equivalent receiving aperture is greatly expanded, and the angle measurement accuracy is greatly improved.

The present application relates to a kind of methods for remote intelligent evaluation of knee joint angle by photo, belong to medical information processing technical field, solve the problem that accurate remote knee joint angle measurement is difficult in prior art.Method includes: obtaining the knee joint side photo of patient;Wherein, the outside of the leg of patient is pasted with flexible marking band;Marking point is arranged on the flexible marking band with equal interval;Hip joint point, knee joint point, ankle joint point in the knee joint side photo of patient and the marking point on the flexible marking band are detected based on trained detection model;Big thigh direction vector and small leg direction vector are fitted based on the hip joint point, knee joint point, ankle joint point and marking point of detection;Knee joint angle is calculated according to big thigh direction vector and small leg direction vector.It is realized to quickly and accurately remote knee joint angle evaluation.

The present invention discloses a system and method for improving the angle measurement accuracy of a vehicle-mounted millimeter-wave radar, belonging to the technical field of vehicle-mounted radars. The system comprises a vehicle-mounted millimeter-wave radar, a gyroscope sensor and a signal processor; the vehicle-mounted millimeter-wave radar is operated to sense target obstacles around a vehicle; wherein the vehicle-mounted millimeter-wave radar has a transmitting antenna and two receiving antennas, and the distance between the two receiving antennas is d; the gyroscope sensor is operated to obtain the current tilt angle α of the vehicle-mounted millimeter-wave radar in the forward direction of the vehicle; the signal processor is operated to receive the sensing information of the vehicle-mounted millimeter-wave radar and the current tilt angle α of the vehicle-mounted millimeter-wave radar, and calculate the projection distance d between the two receiving antennas of the vehicle-mounted millimeter-wave radar based on the information. ， , and then obtain the angle θ of the target obstacle. The system and method of the present invention can improve the angle measurement accuracy of the vehicle-mounted millimeter wave radar installed in the vehicle when the vehicle is tilted.

The application particularly relates to a kind of distributed radiation source warning equipment angle measurement fusion processing methods, comprising: obtaining the interrupt number sent by each distributed warning equipment, alarm report;According to the time information, radiation source detection data are screened to alarm report, to obtain the multiple alarm reports belonging to the same radiation source, and for direction finding fusion processing;According to the signal amplitude parameter of radiation source in alarm report, the multiple alarm reports belonging to the same radiation source are screened, to obtain first alarm report, second alarm report;According to first alarm report, second alarm target report determines the position relationship of corresponding distributed warning equipment, and based on position relationship, the alarm direction of radiation source is direction finding fusion processing to determine the target direction information of radiation source.This method divides angle measurement algorithm into two steps, reduces the distributed warning pressure, also reduces fusion processing pressure.

The present invention relates to the field of positioning technology, and in particular, to an optimized direction finding and ranging positioning method based on UWB. The method is applied to a measuring device, the measuring device includes at least m base stations and tags, each base station includes an antenna array consisting of a main antenna and n slave antennas; the method includes: obtaining the final angle data between the tag and the base station; obtaining the first distance data from the tag to each base station through a preset ranging algorithm; optimizing the first distance data to obtain the second distance data; optimizing the second distance data again through a least squares estimation model to obtain the final distance data; and finally obtaining the location of the tag according to the final distance data and the final angle data and the preset base station position. This solves the problem of how to obtain more accurate measurement angles and distances in a complex environment for more accurate positioning of tags.

The application provides a radar system, a self-calibration method and a vehicle, and relates to the technical field of radars.The radar system comprises: a plurality of radar chips connected in cascade, each radar chip comprising at least one receiving channel; a calibration transmitting module arranged in at least one of the plurality of radar chips, used for generating a calibration signal in a calibration mode of the radar system; a coupling network connected between the internal calibration transmitting module and each receiving channel of the plurality of radar chips, used for distributing the calibration signal to each receiving channel; and a signal processing module used for determining compensation data of each receiving channel according to amplitude differences and / or phase differences between received signals of the receiving channels in the calibration mode, the compensation data being used for compensating signals received by each receiving channel in a working mode of the radar system.Thus, the consistency of radio frequency amplitude and phase can be improved, and the detection performance and stability of the radar system can be improved.

The application discloses a millimeter wave radar-based super-resolution angle estimation method, which comprises the following steps: obtaining multi-element sampling data by receiving echo signals of a transmitting antenna by a receiving antenna; adding a Hanning window in a distance dimension and a speed dimension respectively; performing multi-channel non-coherent accumulation to improve signal-to-noise ratio; performing two-dimensional CFAR detection on the two-dimensional matrix data after non-coherent accumulation, performing CA-CFAR detection in the distance dimension and OS-CFAR detection in the speed dimension respectively, and obtaining matrix data containing a target; resolving and aggregating target points in a point trace condensation mode, so as to form a unique target point trace, and saving distance unit information and speed unit information of the target; and estimating a target azimuth by using an improved forward-backward Root-MUSIC algorithm on the multi-element data after compensation. The method considers that the forward-backward direction only uses the covariance matrix on the main diagonal line, and the application has a significant improvement in angle resolution and angle measurement accuracy.

This application relates to an online correction-based collaborative angle measurement method based on IMM and sum-difference channel amplitude and phase, comprising: acquiring target radar echo signals and constructing complex original observation vectors; constructing a dual-mode IMM motion model, establishing a four-dimensional joint extended state vector and discrete linear global state recursive equations, and initializing them; based on the model posterior probability and model transition probability of the previous time step, obtaining the mixed initial state and mixed initial covariance of each model at the current time step, and performing Kalman prediction and updating respectively to obtain the current angle solution results of each model, and updating the posterior probability; solving for the optimal amplitude mismatch coefficient and phase offset to obtain the corrected sum-difference channel signals of each model; and obtaining the final angle measurement result at the current time step through the corrected sum-difference channel signals of each model. This application can eliminate angle measurement errors caused by channel amplitude and phase offset and maneuvering, and achieve high-precision robust angle measurement under all working conditions.

A bionic polarized light compass angle measurement precision evaluation and angle measurement error calibration and correction method comprises the following steps: performing angle ambiguity resolution on an angle value output by a bionic polarized light compass to obtain an actual measurement angle sequence; generating an ideal rotation angle in a range of 0-360 degrees according to a fixed rotation angle step length, and forming an ideal rotation angle sequence; calculating an absolute error between the actual measurement angle sequence and the ideal rotation angle sequence, and performing mean value correction on the absolute error; and calculating the root mean square error of the absolute error after mean value correction, and evaluating the angle measurement precision of the bionic polarized light compass. A bionic polarized light compass angle measurement error calibration model is constructed on the basis of angle measurement precision evaluation, and photoelectric pixel response non-uniformity errors in a bionic polarized light compass and coupling inconsistency errors between a nano grating array and photoelectric pixels are effectively corrected. According to the invention, the measurement error characteristic of the bionic polarized light compass can be accurately reflected, and the reliability of angle measurement precision evaluation is improved.

The invention belongs to the technical field of airborne radar anti-interference, and particularly relates to a digital array radar multi-beam receiving interference source angle measurement method and device, and the method comprises the steps: S1, obtaining the wavelength, array element interval and array element number of a radar; s2, steering vectors are respectively generated by a plurality of equally-spaced angles, and equally-spaced wave beams pointed by the plurality of angles are formed; s3, determining a wave beam range corresponding to the maximum value of the interference power amplitude of the channel data in each wave beam; and S4, within the wave beam range, calculating an interference source angle by adopting a spatial spectrum estimation method. According to the interference source angle measurement method provided by the invention, the airspace scanning time can be reduced, the defects of high load calculation and time consumption of full-airspace spatial spectrum estimation can be avoided, and the interference source angle measurement precision can be effectively improved compared with a single-pulse angle measurement method.

The application discloses a virtual array-based antenna direction finding method, device and equipment. When performing a direction finding task of a target antenna for the first time, a moving track of the target antenna can be determined according to a direction finding requirement, and a plurality of physical sampling positions can be selected uniformly on the track M The three-dimensional coordinates of the physical sampling positions are recorded. Then the physical sampling positions are equivalent to virtual array antenna elements, and a virtual array antenna is formed according to the track arrangement. A narrowband signal source is received on the virtual array to convert into a complex signal matrix, and a DBF angle estimation is performed on the virtual array antenna based on the complex signal matrix to obtain a preliminary DOA estimation angle, so as to construct adjacent and difference beams based on the estimation angle. The estimation deviation is solved by using the adjacent beams, and the preliminary estimation angle is corrected to obtain a final accurate angle estimation result. The application can improve the DOA estimation precision without increasing the hardware cost and system complexity.

The application discloses a radar single-pulse angle discrimination curve fitting method based on cost sensitivity weighting, which comprises the following steps: 1, measuring sum-difference beam patterns of multiple wave positions in a microwave darkroom or an ideal field environment, and extracting original measurement values of angle discrimination curves in an angle range of interest; 2, constructing a measurement value combination for joint fitting of the angle discrimination function of multiple wave positions; 3, constructing a polynomial fitting optimization problem based on a least square criterion; 4, designing a cost sensitivity function and related parameters according to actual application requirements, and further correcting the cost function; 5, calculating intermediate variables and solving fitting coefficients; and 6, in a radar actual working project, on-line single-pulse angle measurement is completed based on the angle discrimination function obtained through fitting. Through simple parameter setting, the fitting accuracy of targets near the beam pointing direction and targets far away from the beam pointing direction can be flexibly adjusted according to actual application requirements.

The invention relates to a polarization sensor modeling method considering sunlight interference, which comprises the following steps of: dividing light incident to a polarization sensor into three parts, namely linearly polarized light, vertically incident unpolarized light and sunlight, and representing sunlight interference transmission light intensity by considering the influence of sunlight interference on the polarization sensor on the basis of the Malus law; based on a long short-term memory network, polarized light intensity information, a sun vector, polarization sensor calibration parameters, a polarization sensor field angle, an inner wall reflection coefficient and a diffuse reflection coefficient are used as inputs, sunlight interference transmission light intensity and a sunlight proportion are used as outputs, and a polarization angle after sunlight interference compensation is used as a training target. Learning a sunlight interference transmission light intensity equation; influences of linearly polarized light, vertical incidence unpolarized light and sunlight on the polarization sensor are comprehensively considered, a polarization sensor model considering sunlight interference is established by combining a light intensity gain coefficient of the polarization sensor, and polarization information such as a polarization angle and a polarization degree is solved.

The invention provides a photonics large-bandwidth two-dimensional arrival angle estimation device and method, and belongs to the technical field of wireless radio frequency. The photonics arrival angle estimation device comprises a receiving antenna A1, a receiving antenna A2, a receiving antenna A0, a first optical domain delay matching channel, a second optical domain delay matching channel, a reference optical domain delay channel, an optical splitter, a first balance photoelectric detection unit, a second balance photoelectric detection unit and a feedback control module. According to the photonics large-bandwidth two-dimensional arrival angle estimation device and method, on the basis of coherent characteristics of received signals of adjacent antenna array elements, a pitch angle and an azimuth angle of an incoming wave signal are obtained through optical domain delay search by adopting photonics microwave signal transmission and balance detection, prior information such as frequency and bandwidth of the incoming wave signal is not needed, and the estimation accuracy is high. The antenna has the advantages of wide working frequency range, large bandwidth and high angle measurement precision.

Disclosed in the embodiments of the present invention is a low-magnetic-field magnetoresistive angle sensor. The sensor comprises: a substrate located in an X-Y plane, and a magnetoresistive sensing unit located on the substrate. The magnetoresistive sensing unit comprising a multi-layer thin film structure. The multi-layer thin film structure comprises at least a stack of a free layer, a barrier layer, and a reference layer. The magnetoresistive sensing unit has an oval shape. The oval-shaped free layer has a long axis Ly, a short axis Lx, and a thickness Lz. Additionally the free layer has a saturation magnetic field, a shape anisotropy demagnetizing field, and a magnetocrystalline anisotropy field in the X direction. When an external magnetic field rotates by 0-360° in the X-Y plane, the magnetocrystalline anisotropy field is compensated by the shape demagnetizing field to cause the effective anisotropy field of the free layer to be close to 0, such that the external magnetic field has a low working magnetic field value close to that of the saturation magnetic field of the free layer material. The embodiments of the present invention can improve the accuracy of angle measurement of a magnetoresistive angle sensor. Additionally because the required external magnetic field is low, the sensor can be implemented at low cost.