60results about How to "Improve position estimation accuracy" patented technology

Disclosed is a car navigation system and method. The present invention includes a sensor unit including a plurality of sensors, each, configured to measure a state of a vehicle using a predetermined scheme and to obtain sensor data; a vehicle to everything (V2X) unit configured to receive the sensor data from the sensor unit, and including a global navigation satellite system (GNSS) module to thereby receive a satellite signal and to generate GNSS data; and a position estimator configured to receive the sensor data and the GNSS data from the V2X unit, to evaluate an accuracy of each of the sensor data and the GNSS data using a predetermined scheme, and to obtain position coordinates of the vehicle by merging GNSS position coordinates obtained from the GNSS data and dead reckoning (DR) position coordinates obtained from the sensor data based on the evaluation result.

The invention relates to a homography estimation and extended Kalman filter based localization method for a UAV. Online image splicing is used to eliminate an accumulative error of position estimation of the UAV, an environment map is constructed in real time, and the accuracy of position parameter estimation of the UAV can be effectively improved. According to the method, online image splicing is used to eliminate the accumulative error of position estimation of the UAV, accurate estimation for the UAV position parameter is realized on the basis of robust estimation for an image inter-frame homography matrix by considering the homographic relation and indeterminacy among images, extended Kalman filter is used to predict and update a UAV position estimation result, and the UAV position estimation precision is improved substantially.

The invention relates to a Doppler frequency deviation correction method. The method comprises performing characteristic analysis on target radiation noise; building a receiving model and establishing a rectangular coordinate system for a towed line array; presetting the frequency point compensation total; performing Fast Fourier Transformation (FFT) and frequency domain beam forming on signals at certain initial moment and after the towed line array moves for certain time, and accumulating output results of frequency domain beam forming at the current frequency point; calculating a space moving compensation and a time delay compensation to obtain the total phase correction compensation, and obtaining the virtual array expansion output result according to the previous compensation result and the total phase correction compensation; obtaining a time azimuth course diagram, detecting the target signals through the time azimuth course diagram, determining if current frequency point compensation times reach the frequency point compensation total, changing the amplitude of the current frequency point if the compensation times do not reach the frequency point compensation total, and performing sampling again till the current frequency point compensation times reach the frequency point compensation total.

The invention discloses a fast SRP sound source positioning method. The method comprises the steps that the optimal weight of a Farrow structure beamformer is acquired; the phase weighting function of the Farrow structure beamformer SRP-PHAT is calculated; the sum of generalized cross-correlation functions of all pairwise microphones of the Farrow structure beamformer SRP-PHAT is calculated and latched; product adding is carried out on a latched output signal and a unique yawing parameter D relevant to the scanning angle of the Farrow structure beamformer, so as to acquire the instantaneous power of a corresponding scanning point; the maximum peak is searched to acquire a corresponding positioning angle theta r'; and finally calibration is carried out to eliminate system errors of the Farrow structure beamformer to acquire a final theta r. Compared with former SRP-PHAT, the method provided by the invention has the advantages of reduced computation amount, higher reverberation and noise robustness, and higher azimuth estimation accuracy.

Disclosed is a position estimation method for estimating a position of an interference signal source and a position estimation system for performing the method. The position estimation method may implement an indoor delay-space analysis structure by transmitting and receiving a known signal and a virtual array structure-based direction finding algorithm in an indoor environment in which a plurality of reflected waves is present and may increase an estimation probability for the position of the interference signal source.

The invention belongs to the radio signal positioning method technical field and relates to a multi-target direct positioning method for non-circular signals. According to the method, the extended covariance matrix of time-domain signals is obtained according to the non-circular characteristics of the signals and on the basis of a time-domain array signal model; noise subspaces in each time slot are calculated through using the extended covariance matrix; the data of the plurality of subspaces are fused on the basis of the orthogonality of the extended subspaces in each time slot, and therefore, an optimization model for each target position is built; and a Gauss-Newton iterative algorithm is designed to realize the precise positioning of each target sequentially. With the multi-target direct positioning method for the non-circular signals provided by the invention adopted, multi-target position estimation accuracy can be improved. The advantages of the method in positioning accuracy become more obvious with the decrease of a signal-to-noise ratio or the decrease of sample points; and the method can process a larger number of targets.

The invention provides a mobile robot synchronous positioning and map construction method which comprises the following steps: (1) establishment of system models including a robot motion model, an observation model and an environmental characteristic model; conversion of the colored process noise model into a white Gaussian noise model; (2) setting of initial parameters of a mobile robot synchronous positioning and map building algorithm, wherein the initial parameters comprise dead reckoning system parameters and laser radar parameters; (3) state prediction; (4) observing; (5) data association; (6) updating; and (7) state augmentation. The method is characterized by comprising the step (6), in the measurement updating process of standard volume Kalman filtering, an adaptive factor is selected, an autocorrelation covariance matrix and a cross-correlation covariance matrix are adaptively adjusted, the updating process is completed, and meanwhile, the weight ratio between system model prediction information and measurement information can be balanced, so that the positioning precision and the map construction precision are improved.

The invention discloses a compensation method for position estimation of a rotor of a permanent magnet linear motor by a high-frequency injection method, which comprises the following steps of: filtering a current response signal to obtain a first current signal and a second current signal, and designing a first compensation vector and a second compensation vector according to included position estimation error information; multiplying the first compensation vector by the first current signal and the second current signal respectively to obtain a first current vector and a second current vector; carrying out low-pass filtering on the second current vector, subtracting the second current vector from the first current vector, and multiplying the second current vector by the second compensation vector to obtain a second current difference vector; sending the imaginary part of the second current difference vector to a PI regulator for integration to obtain a mover estimation position; andtaking the mover angular frequency estimated value and the mover position estimated value as feedback signals, and controlling the difference between the actual position of the motor mover and the mover estimated position to converge to zero, so that the motor operates stably. The method can obviously inhibit the position estimation error caused by the end effect, effectively improves the precision of estimating the position of the linear motor rotor by adopting a high-frequency injection method, and is simple and easy to implement.

A business form including a wristband is provided with a print area forming a badge, the badge having a length less than and a width greater than a width of either of two straps used to attach the wristband to the wrist, the badge thus having a greater print area to improve the readability of the indicia displayed therein. A business form including a wristband has a bulged rectangularly shaped print area to allow information to be printed transversely across the print area to improve readability of the indicia displayed in the print area. Thus, the bulged rectangularly shaped print area can accommodate one or both of bar codes printed thereon in ladder as well as picket fence fashion.; A security seal is disclosed which comprises a small, adhesive coated patch of laminate for sealing the joinder of the wristband ends and which has points of weakness such as X's die cut therein so that it separates or destructs upon removal to provide an indication of tampering with the wristband. Alsodisclosed is an embodiment of the wristband form that is imprinted with identifying indicia for collecting, tracking and administering a patient's blood collection and blood product compatibility.

An artificial intelligence based indoor fingerprint positioning method comprises following steps: step one, in the offline phase, using an affinity propagation clustering technology to sample sparselydistributed reference points to obtain fingerprint, carrying out clustering to divide an indoor area into N sub-areas (N is a specific integer), then utilizing the sampling data of each sub-area to establish a RPM route loss propagation model, and through the model, predicting the fingerprint of other unmeasured reference points so as to establish a complete fingerprint database; and step two, inthe online phase position estimation and tracing phase, improving the initialization strategy of a PSO algorithm to improve the convergence speed and global convergence performance of the algorithm so as to enhance the position estimation precision; and at the same time, utilizing a Kalman filtering algorithm to further correct and smoothen the position estimation result so as to obtain a terminal position tracing effect with higher precision.

A position estimation device including: a provisional position setting unit which sets current position information indicating an estimated current position of a wireless terminal; a distance estimation unit which estimates, using receiving strengths of signals received from plural wireless stations, distance information indicating distances from the plural wireless stations to the wireless terminal; a possible area calculation unit which calculates, using the distance information and map information indicating a spatial structure, an area in the spatial structure which can maintain the distances indicated in the distance information, as a possible area in the spatial structure in which the wireless terminal is likely to be present; and a correction unit which corrects the current position indicated in the current position information to a position within the possible area when the current position is outside the possible area.

The invention discloses a surface-mounted permanent magnet synchronous motor sensorless segmented delay compensation strategy, which specifically comprises the following steps of: when the fundamental frequency of a motor is less than 47Hz, carrying out PI (Proportional-Integral) regulation on a predicted q-axis voltage error by using carrier modulation, and then eliminating the influence of total time delay of a system by compensating the conduction time of an IGBT (Insulated Gate Bipolar Translator); and after the fundamental wave frequency is greater than 47Hz, along with the increase of the rotating speed, adopting a SHEPWM + square wave modulation mode, and elimiating the delay effect by predicting a voltage vector angle, modulating the depth and estimating the rotor position. The invention provides a system delay segmentation compensation strategy aiming at the sensorless driving of the surface-mounted permanent magnet synchronous motor under hybrid pulse width modulation, meanwhile, a high-frequency square wave voltage signal injection method is adopted at zero low speed, a nonsingular terminal sliding-mode observer is adopted at medium high speed, the non-singular terminal sliding-mode observer is adopted at low speed, the influence of system delay on position sensorless control can be eliminated in the full-speed domain, and the control performance is improved.

The invention discloses an indoor parking system based on Wi-Fi position fingerprints. The system comprises a user service module and a system management module, wherein a parking service module and aposition estimation module are arranged in the user service module, the parking service module is used for parking service of a user, and the position estimation module is used for helping the user to quickly find the position of a vehicle and the position of the vehicle in a parking lot based on indoor positioning of a WIFI position fingerprint; a user management module and a parking lot management module are arranged in the system management module; the user management module is used for managing user information. According to the invention, a user can enjoy convenient parking and positioning services, management personnel can manage parking management conveniently, and the parking management system has the characteristics of convenient use, accurate positioning and high management efficiency.

The invention discloses a built-in permanent magnet synchronous motor sensorless parameter error compensation strategy. The strategy specifically comprises the steps of carrying out the estimation of an MT shaft current based on a flux linkage indirect calculation method, replacing an estimation value with a given flux linkage, and improving the flux linkage-based rotor position estimation, acquiring deviation coefficients mu and lambda, correcting permanent magnet flux linkage and quadrature-axis inductance parameters online in real time, and using the corrected parameters for calculation of the maximum torque current ratio control stator flux linkage given value of the motor, MT-axis current estimation and load angle calculation. The invention provides a parameter error compensation strategy forbuilt-in permanent magnet synchronous motor sensorless control under the low switching frequency SHEPWM modulation, which can correct the permanent magnet flux linkage and quadrature axis inductance parameter deviation in real time, thereby improving the rotor position estimation precision and enhancing the system robustness.

The invention discloses a switched reluctance motor sensorless method based on a difference inductance vector method, and belongs to the field of switched reluctance motor sensorless control, and the method comprises the following steps: calculating a three-phase inductance value of a switched reluctance motor in real time; delaying a three-phase inductance value expressed in a Fourier series form by pi degrees; carrying out mutual subtraction on the three-phase inductance difference values to obtain three-phase-difference-value inductance; carrying out unitization on the obtained three-phase difference value inductance; performing logic partitioning on the three-phase difference value inductor; estimating to obtain rotor position angle information at any moment in a single period by utilizing an arc tangent function and combining with three-phase difference inductance logic partitioning; according to the rotor position angle information at any moment, outputting a corresponding control signal to the switched reluctance motor to control the on and off of a power switch tube of a power converter so as to realize the sensorless control of the switched reluctance motor; the method can improve the estimation precision of the rotor position, achieves the high-precision control of the switched reluctance motor, and has a wide application prospect.

A permanent magnet synchronous motor low speed section position sensorless control method without high frequency signal injection is disclosed. An asymmetric space vector pulse width modulation methodis adopted, three effective voltage vectors with electrical angle difference of 120 degrees and one zero vector are used to synthesize a target vector, so that when the system is in the low modulation region or even the output target voltage vector is zero, the three effective vectors are not zero in the action time and large enough to ensure detection of the phase current change under the actionof the effective voltage vectors; based on the inductance convex polarity principle, the current variation of three effective voltage vectors and one zero vector are calculated, and a rotor positionis estimated from those current variations including position information. The invention can realize low speed segment position sensorless control without high frequency signal injection.

The invention belongs to the field of motor control, and particularly relates to a switched reluctance motor sensorless control method. The method comprises: establishing a simplified incremental inductance model based on the simplified Fourier series expression of switched reluctance motor inductance and the relational expression of incremental inductance and inductance; measuring the incrementalinductances of three special rotor positions of a switched reluctance motor under different phase currents so as to obtain a relation that an incremental inductance model coefficient changes along with the phase currents, and establishing the nonlinear incremental inductance model of the switched reluctance motor; deducing an analytic expression for estimating the rotor position of the switched reluctance motor according to the phase increment inductance and the coefficient thereof according to the increment inductance model; and when the motor operates, detecting phase current and bus voltage, estimating excitation phase increment inductance by adopting a current slope difference method, calculating the current rotor position by utilizing the derived rotor position analytical formula, and achieving the sensorless operation control of the switched reluctance motor according to the estimated rotor position. The control method is simple, small in calculation amount, easy to realize digitalization and high in position estimation precision.