50 results about "Track-before-detect" patented technology

The invention provides a target track-before-detect (TBD) method based on multi-frame coherent integration. The method is characterized in that a new TBD method is provided aiming at the fact that when multi-frame integration is carried out, the phase information of target echo is not utilized in the traditional TBD method. According to the method provided by the invention, a signal to noise ratio is improved through multi-frame echo coherent integration by utilizing the phase information of the target echo; and by using the method in the invention, the detection of a weak target can be effectively achieved under the condition of less echo data frame numbers, the detection efficiency is improved, and the position speed information of the target is provided while detecting so as to realizethe track of the target.

The invention discloses an HT-STC-TBD (Hough Transform and Successive Target Cancellation Based Track-Before-Detect) detection method for multiple weak targets under a radar-ranging fuzzy condition and belongs to the field of radar data processing. The HT-STC-TBD detection method comprises the following steps: (1) sending a measured target value which is detected by a high/middle pulse repetitionfrequency radar (such as an airborne pulse Doppler radar) into a data processing computer and then acquiring all the possible states of a target in the data processing computer; (2) performing Hough transformation on the possible states, thereby acquiring an energy accumulation column diagram; (3) searching for a peak value of the energy accumulation column diagram and performing Hough inverse transformation according to a peak value coordinate so as to confirm a valid detecting data point; (4) eliminating a false track, modifying a state of the target and realizing once target tracking; (5) eliminating the influence of the last detection and secondarily detecting the target; and (6) repeating the steps (3)-(5) till all the targets are detected, thereby realizing the tracking and detection of multiple weak targets.

The invention discloses a multi frame coherent accumulation target track-before-detect method based on dynamic programming. According to the invention, dynamic programming is used to acquire a possible track of a target in frames of echo data; and estimation and compensation are carried out on the quadratic term of the echo phase of the target, and coherent accumulation is carried out on the target echo in frames of echo data, so as to improve the output signal to noise ratio and weak target tracking is realized. Compared with a conventional non coherent TBD method which does not use the phase information of the target echo when accumulation between frames is carried out, the method provided by the invention uses the phase information of an echo signal when accumulation between frames is carried out. By using fewer frames of echo data, the output signal to noise ratio is improved, thus the target detection probability is improved. The trajectory and the motion information of the target are provided, so that target tracking is realized.

The invention discloses a tracing accumulation method of coherent detection based on dynamic programming and a back image projection algorithm, comprising the following steps of: obtaining a predication track of a target through the dynamic programming; and then carrying out energy accumulation through the back image projection algorithm to improve an output signal to noise ratio, so as to realize the detection on a low observable target. Compared with a non-coherent TBD (Track Before Detect) algorithm, the method uses phase information of an echo signal when inter-frame accumulation is carried out, and coherent accumulation is carried out on a multi-frame echo to improve an output signal to noise ratio and further improve the detection efficiency; a distance migration compensation is directly carried out on a time domain, so that approximate unfolding of a target distance does not need to be carried out, and Doppler migration of a target is not considered; and therefore, an accumulation error is reduced, the detection possibility and the detection precision are improved, and the false alarm probability is reduced.

The invention provides a track-before-detect method based on a G0 clutter background and a constant target amplitude. Aimed at a constant-amplitude target, the method builds a model of a clutter background in a G0 distribution. As there is no analytical solution for the measurement value amplitude likelihood ratio, the method uses a weighted sum of gamma functions to approximate to the likelihood ratio, and thus the method is suitable for G0 clutter background and constant target amplitude situations. The method uses the weighted sum of the incomplete gamma functions as the value function. As the weighted sum of the incomplete gamma functions and the likelihood ratio use clutter parameters and target parameters, compared with a dynamic-programming track-before-detect algorithm in the prior art, the method fully utilizes the background and clutter information and better reflects the difference between the target and the clutter.

The invention discloses a rapid dynamic programming track-before-detect method suitable for a radar system, belongs to the technical field of radar target detection, and relates to a track-before-detect technology of a weak target in a radar system. The method comprises the steps of: firstly carrying out pre-processing on measurement of a radar, and enabling the measurement of the radar to be corresponding to a discrete state space which is less in quantized state; and carrying out dynamic programming searching based on preprocessed data, and estimating a target stat sequence with less calculation amount. Then, by adopting an estimated result, fine searching is carried out on only a few related states, the accurate position of the target is determined, a large amount of meaningless searching is effectively avoided at the same time, and the calculation amount is substantially reduced.

The invention discloses a weak target track-before-detect method based on traversal random Hough conversion. In the method, clutter suppression first threshold processing is firstly performed on all frames of radar echo data and different frames of data exceeding a first threshold are stored in a separate manner; then all the radar echo data exceeding the first threshold are superimposed in a data space; during Hough conversion on all the points in the data space, the invention proposes a traversal pairing idea, which is a method for performing one-to-one pairing on all the different points in the data space so as to obtain linear parameters; then traversal Hough conversion is performed on all the points in the data space so as to obtain the linear parameters; then voting is performed on the to-be-solved linear parameters; and at last a linear parameter with the maximum vote value is extracted so that track backtracking is realized. The weak target track-before-detect method based on the traversal random Hough conversion is capable of realizing weak-target detection and tracking under a complex background environment and greater in detection performance and tracking precision at the same time.

The invention belongs to the technical field of radar target detection tracking, and particularly relates to a complex likelihood ratio track-before-detect method based on dynamic planning. The method includes the following steps of receiving radar echo data by means of radar, preprocessing the radar echo data to obtain a preprocessed image, carrying out track-before-detect by means of a dynamic planning method according to the preprocessed image to obtain a target track, building a complex likelihood ratio function according to the preprocessed image when track-before-detect is carried out in the dynamic planning method, and building a value function of the dynamic planning method according to the complex likelihood ratio function.

The invention discloses a high repetition frequency radar target track-before-detect method based on regional mapping ambiguity resolution. The high repetition frequency radar target track-before-detect method overcomes the problem that a track-before-detect method cannot effectively track a target due to a blurred track of the target in a high repetition frequency system. The high repetition frequency radar target track-before-detect method is characterized by comprising the steps of subjecting a measuring plane of each repetition frequency to regional mapping on a distance dimension so as toobtain a dimension expansion plane, performing multi-frame joint accumulation of the dimension expansion planes of the repetition frequencies, and acquiring an ambiguity point sequence with high confidence coefficients, and finally acquiring an unambiguous target track by utilizing a track calibration method for solving range ambiguity. The high repetition frequency radar target track-before-detect method effectively solves the problem that the track-before-detect method cannot be applied to the high repetition frequency system radar with range ambiguity, and can realize stable detection andprecise tracking of a weak target by utilizing high repetition frequency radar fuzzy measurement.

The invention provides a micro-motion characteristic cognition extraction method for a rotating symmetrical object. The method comprises the steps of a first step, acquiring object scattering point distance track information by means of a track-before-detect method; a second step, fitting a micro-motion parameter by means of the distance track information, and on the contrary, updating a state transfer set function in a track-before-detect process according to a micro-motion parameter estimation result; and a third step, comprehensively considering a setting and determining principle at two aspects of object detection and micro-motion characteristic extraction, thereby determining whether an object detection and micro-motion characteristic extraction task is finished. The micro-motion characteristic cognition extraction method can simultaneously realize object micro-motion characteristic extraction in performing detection and tracking on an object and furthermore improves radar working efficiency.

The invention relates to a Hough transform-based track-before-detect method of multidimensional parameters. The method includes the steps of performing initializing to determine a target track initiation, as an initial detection result; allowing cycling for a third detection; according to a last detection result and characteristic parameters extracted via the current detection, performing differencing and comparison of judgment thresholds, and performing judging; according to judging results, tracking a target; performing filtering if certain characteristic parameter of the target is divergent, directly executing Hough transform if the characteristic parameter is not divergent, and performing energy accumulation; according to a target accumulated energy and an accumulative threshold, performing comparing, and performing adaptive updating and judging the threshold; using the target of the accumulative threshold as a final detection result, and starting a next cycle. The method has the advantages that the pre-detected track is avoided being divorced from actuality, false tracks are eliminated, and the ability of radar to detect, track and distinguish multiple moving targets is improved.

The invention discloses a maneuvering weak target Track-before-Detect method of interactive multi-mode Bernoulli filtering. The maneuvering weak target Track-before-Detect method of interactive multi-mode Bernoulli filtering is characterized in that on the basis of Bernoulli particle filtering, an interactive multi-mode method is used to predict the sampling particle of each target state, and thena prediction particle is substituted into a traditional Bernoulli TBD (Track-before-Detect) algorithm to perform update estimation of the existing probability and distribution density of the targets.In the low signal to noise ratio situation, the maneuvering weak target Track-before-Detect method of interactive multi-mode Bernoulli filtering can effectively detect and track the weak maneuveringtarget, and can be more accurate in estimation of the target state.

The invention discloses a multi-target track-before-detect method based on probability hypothesis density filtering. The method deeply analyzes the problem of a traditional method and points out the essential reason of the problem of the traditional method that the traditional method considers that one target influences the observation of a whole area and also considers that the number of each frame of false alarm can be approximated into one constant value, i.e. the traditional method does not comply with two pieces of basic hypothesis for realizing PHD (Probability Hypothesis Density) filtering: firstly, one target only can generate one observation, and secondly, the number of each frame of false alarm must submit to Poisson distribution on an aspect of time. In order to solve the problems, the invention puts forward the multi-target track-before-detect method based on the probability hypothesis density filtering, can improve the accuracy of target number estimation, enhances detection and tracking performance, and also achieves an effect on lowering a calculated amount.

The invention provides a maneuvering target multi-frame track-before-detect method applied to a pulse-Doppler radar, which can carry out real-time estimation on the target radial acceleration and the current acceleration mean value by using Doppler information of a state in an accumulating path during a dynamic planning value function accumulation process. Thus, the adaptability of the dynamic planning track-before-detect method to the maneuvering target can be effectively improved. In addition, estimation on the target radial acceleration and the current acceleration mean value is guided by measurement and can be adaptively completed, and specific target prior information is not needed.

The invention discloses a permanent magnet synchronous motor anti-demagnetization control method which comprises the following steps: first, detecting motor speed and motor phase current, second, if the motor speed is less than the maximum speed of revolution of track before detect percent (TBD%), a system becomes invalid and detects the motor phase current to be over a threshold value, and a controller controls six switching tubes of a three phase permanent magnet synchronous motor to open, third, after n plurality of seconds, entering a next three insulated gate bipolar transistor (IGBT) short circuit module of the three phase permanent magnet synchronous motor, three switching tubes on the three phase permanent magnet synchronous motor keep opening, and the next three switching tubes of the three phase permanent magnet synchronous motor are controlled. According to the permanent magnet synchronous motor anti-demagnetization control method, when normal rotate speed operation of the motor is shifted into the next three IGBT short circuit pattern of the three phase permanent magnet synchronous, an instantaneous peak value large current produced according to an original method is reduced, and the risk of motor permanent magnet steel demagnetization is prevented or reduced. So when the motor is designed, magnetic circuit design can be carried out based on the reduced instantaneous peak value current, magnet steel with low coercivity is chosen, rare earth content is reduced, and the purpose of reducing cost is achieved.

The invention relates to a detection method based on a Hough transform domain clutter map for a small target in a heavy clutter region. The detection method is mainly suitable for track-before-detect of the small target in the clutter region with strong correlation between sampling. The detection method utilizes correlation difference of the target at interframe positions through joint processing of multiframe echo signals, and realizes echo amplitude non-inherent accumulation of the target. A plurality of frames of the echo signals at adjacent detection intervals are taken out in sequence and subjected to Hough transformation, so as to construct a clutter map in a transform domain. When refers to newly occurred target echoes, point number of moving trajectory parameters, corresponding to lattices of the clutter map, of the target echoes can be increased. The increased number of echo points in the lattices of the clutter map serves as a bases for detecting the target, and the moving trajectory of the target is inverted through parameters corresponding to the lattices.

The present invention provides an approximate space target tracking method under the influence of stealth and hypersonic velocity. According to the method, a TBD (track before detect) algorithm is improved in point accumulation, recursive flight tracks are adopted to replace traditional point accumulation, the point accumulation is not composed of batch processing measurement at a plurality of time points any more, but composed of measurement at one time point and existing flight track points at m-1 time points, and therefore, the algorithm has real-time performance, and the problem of time delay difference caused by the hypersonic-velocity movement of a target can be effectively solved; the TBD (track before detect) algorithm is improved in energy accumulation, recursive energy is adopted to replace traditional energy accumulation, and therefore, the algorithm can effectively overcome a detection problem caused by the stealth of the target when tracking the target in real time; and the recursive flight tracks and the recursive energy are organically combined, and the effective tracking of the stealth high-speed target can be realized through the reasonable decision of a maximum recursive energy decision mechanism.

The present invention provides an efficient particle filter based track before detect (EPF-TBD) method based on an object existence probability slope. According to object existence probabilities, existence judgment is carried out. At an initial moment, an existing probability of an object at a current moment and a threshold value are compared for judgment; if the existing probability of the object at the current moment is larger than the threshold value, the object at the current moment is judged to exist, and the object at the current moment is judged to not exist otherwise; at other moments apart from the initial moment, a variation between the existence probability of the object at the current moment and that of the object at the last moment is judged if to be larger than a threshold value, if so, an existence judgment result of the object at the current moment is different from that of the object at the last moment, and the existence judgment result of the object at the current moment is the same as that of the object at the last moment otherwise. With adoption of the EPF-TBD method provided by the present invention, missing detection and false alarm problems can be effectively relieved, and the detection performance is excellent.

The invention discloses a method for ship target detection under the background of heaven and ground wave radar widening clutters. The method comprises steps as follows: firstly, a pseudo point trackin radar echo is given by use of a low-threshold target detector, pseudo point tracks of multiple accumulation cycles are processed by use of a TBD (track before detect) algorithm based on dynamic planning, a track is given to points which belong to a target point track in the pseudo point tracks, and class target clutter points in the pseudo point tracks are filtered out. Through sufficient combination of actual measurement data samples, TBD and a self-adaptive detection method are combined, anda target detection method of target clutter distinguishing of the TBD algorithm based on dynamic planning of multiple accumulation cycles is proposed. Actual measurement data results prove that the method can distinguish target points and clutter points in the low-threshold target detector to a great extent, and provide more accurate pilot information for following clutter suppression and clutter background extraction.

The invention discloses a dynamic programming track before detect method for moving platform radar based on motion compensation search, is applied to the field of radar target detection, and aims at solving the problem of difficult determination of discrete state space caused by mismatch of measurement grids under the moving platform. Firstly a time-varying measurement gridding method is utilizedto discretize the whole state space, then the position of the state cell in the absolute geodetic coordinate system is calculated by the method of coordinate system change, then the possible positionof the last frame is speculated according to the search speed and finally the effective state space range of the search is calculated according to the motion compensation so as to complete the value function accumulation process in the dynamic programming track before detect algorithm under the moving platform. The dynamic programming track before detect algorithm is enabled to be adaptive to themoving platform radar by the scheme under the condition of low calculation amount and high tracking accuracy, and the detection and tracking performance of the radar for weak targets can be greatly enhanced.

The invention provides a particle filter method for tracking dot trace sequences before multi-frame detection. This domestic invention uses the short track obtained by the multi-frame detection pre-tracking process to filter the target state, which can improve the accuracy of target state estimation; further processing the short track obtained by the multi-frame detection pre-tracking process, The long-term tracking of the target is realized, and the problem that the multi-frame detection-before-tracking method cannot provide the complete track information of the target is solved; the real-time estimation of the target state can be iteratively estimated without introducing too much storage and calculation; through Particle state prediction can effectively solve the problem of missed detection that may occur in the tracking of weak targets with low signal-to-noise ratio before detection, ensuring the continuity of the track.

The invention discloses a multi-target TBD (Track-Before-Detect) method, belongs to the technical field of radar, and relates to a target detection and tracking method. The method can be used for the detection and tracking of a radar weak target in a strong noise/noise environment. Aiming at a problem that a conventional dynamic planning algorithm has a value function extension problem, the invention proposes a new multi-target TBD algorithm. The algorithm employs a new value function calculation mode, eliminates a value function extension phenomenon, and achieves purposes of reducing the number of false flight paths and improving the detection and tracking performance of a radar for an adjacent target. Through the correction of value function calculation, the method effectively eliminate the value function extension phenomenon, thereby reducing the number, exceeding a threshold value, of value functions, reducing the number of the false flight paths, and improving the detection and tracking performance of the adjacent target.