36 results about "Direction finding algorithms" patented technology

A method for locating partial discharge of electrical equipment is used for detecting and locating partial discharge of the electrical equipment. The technical scheme includes the steps: firstly, using three ultrasonic array sensors to receive partial discharge ultrasonic signals at different positions of the electrical equipment and forming an array model; then, converting broadband signals received by the three ultrasonic array sensors into narrow-band signals by applying a TLS (transport layer security)-based broadband focus algorithm, and obtaining azimuth information of partial discharge sources according to a narrow-band direction-finding algorithm combining the phase matching principle and cloud optimization search; and finally, determining specific positions of electrical equipment partial discharge by means of a partial discharge source location algorithm based on global optimization search of a modified genetic algorithm. The invention simultaneously provides an improved system for locating partial discharge. Compared with a traditional method for locating partial discharge, the method has the advantages of small calculation amount, high direction-finding precision, accuracy in location, high convergence rate and the like, and the system for locating partial discharge is simple in structure, low in cost and high in location precision.

The invention discloses a direction finding method for a three-channel spatial spectrum estimation direction finding system. The system comprises a direction finding antenna array, three common-frequency multi-channel receivers and a direction finding algorithm processor, wherein the direction finding antenna array is a 9-element uniform circular array and is provided with an antenna select switch for selecting different antenna elements in the antenna array; three antennas are selected by the antenna select switch each time, wherein the No. 1 antenna is required to be selected each time; 1, 2 and 9, 1, 3 and 8, 1, 4 and 7, and 1, 5 and 6 are selected, wherein each number represents the number of the selected antenna, and the four groups of antennas are alternately selected; the direction finding receivers are of three-channel; and three antennas selected by the antenna switch each time are connected with the three common-frequency multi-channel receivers respectively. By researching the spatial spectrum estimation direction finding technology and improving an MUSIC direction finding algorithm, receiving channels are reduced under the condition of not reducing the antenna elements; meanwhile, the direction finding performance is guaranteed to be unchanged; and the aims of lowering the cost of the direction finding equipment and improving the reliability of the equipment are fulfilled.

The invention discloses a direction finding device for a phase interferometer and a phase spectrum interferometer based on an orthogonal/non-orthogonal multiple baselines. According to direction-finding algorithms of the phase interferometer and the phase spectrum interferometer, the direction finding device is designed by integrally considering factors such as an actual direction-finding environment, the frequency range of an incident signal, the direction-finding requirement, hardware sources and the like. According to the direction finding device, the processing of a digital signal is cooperatively finished by two FPGAs (Field Programmable Gate Array) and a DSP (Digital Signal Processor); and two direction-finding algorithms of the phase interferometer and the phase spectrum interferometer based on the orthogonal/non-orthogonal multiple baselines are realized respectively for a narrow frequency band single-source signal and a wide frequency band multi-source signal. The direction finding device has the advantages of simple algorithm, high speed of calculation, higher direction finding precision and lower requirement on hardware resources; and the direction finding device can beused in application occasions such as quick acquisition of two-dimensional arrival direction of a single-source or multi-source signal and the like.

The invention discloses a partial discharge direction finding method based on an ultrahigh-frequency phased array principle in a substation. The method includes following steps: (1) acquiring and recording partial discharge signals in the substation by employing the ultrahigh-frequency phased array and a digital detection device with high sampling rate; (2) focusing the partial discharge signals to form narrowband signals at a reference frequency point by employing a broadband focusing algorithm; (3) performing direction-of-arrival estimation on the narrowband signals by employing a narrowband direction finding algorithm; and (4) obtaining the point with maximum azimuth density with combination of multiple direction-finding results, namely the azimuth of the partial discharge signals. According to the method, the size of the ultrahigh-frequency phased array is small so that tour inspection is facilitated, and the spatial resolution is high; and according to the method, for the partial discharge signals in the substation, the partial discharge signals are converted to the narrowband signals by employing the focusing algorithm, and the azimuth of the partial discharge signals is obtained by employing the direction finding algorithm so that the direction-finding precision is high, and the ability of suppressing noise interference is great.

The invention relates to the field of MIMO radar (multiple-input multiple-output radar) super-resolution direction finding algorithm, discloses an MIMO radar super-resolution direction finding algorithm of coherent signal sources under the color noise background, and particularly provides an improved spatial difference smoothing (ISDS) algorithm. Besides, a fast algorithm based on a propagation operator, i.e. a PM-ISDS algorithm, is also provided based on the ISDS algorithm. Theoretical analysis and simulation prove that the algorithm has extremely high color noise suppression capacity, and the estimate performance is better than that of the common spatial smoothing algorithm so that the algorithm has great array element saving and signal source overload capacity without performing characteristic value decomposition and has low computational burden.

The invention relates to a regularization least square subspace crossing target direction finding method. According to the method, the Tikhonov regularization method and the least square subspace crossing algorithm are combined to process received signals of a shallow-sea sonar apparatus. On a basis of constructing a least square problem through the utilization of the subspace crossing principle, and then through the regularization method, optimal regularization factors are determined, so that detection and accurate positioning of shallow-sea targets are finally realized. According to the regularization least square subspace crossing target direction finding method of the invention, the Tikhonov regularization method and the least square subspace crossing algorithm are combined for form a new direction finding algorithm. Compared with routine wave beam formation algorithms, the method is better in direction resolution performance and higher in accuracy degree, and the value calculating is stable.

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 discloses an unmanned aerial vehicle interference countering system and belongs to the field of unmanned aerial vehicle prevention and control strategies. The system comprises an interference module, a center control module and a direction-finding module, wherein the direction-finding module comprises N direction-finding stations; each direction-finding station comprises an antenna array, a direction-finding algorithm module, a GPS signal module and a first communication module; the interference module comprises an antenna array, a servo device, an interference signal generationmodule and a second communication module; and the center control module comprises a positioning module, a signal time-frequency characteristic analysis module, an interference decision module, a display module and a third communication module. The first communication module of each direction-finding station is connected with the third communication module of the center control module to realize signal transmission; and meanwhile, the third communication module of the center control module transmits a signal to the second communication module of the interference module. Through the countering means, complexity is low, difficulty is low, safety is high, and cost is low.

The present invention discloses a sonar signal processing method based on a ZYNQ-7000 platform. The ZYNQ-7000 platform comprises a dual-core processor and a FPGA which perform data interaction through an AXI bus protocol; prior to the sonar signal processing, the FGPA source of the ZYNQ-7000 platform is estimated; the MVDR direction finding algorithm is divided into a main body algorithm and an auxiliary algorithm based on the estimation result and the MVDR direction finding algorithm; the main body algorithm is realized on the FPGA, and the auxiliary algorithm is realized on the dual-core processor; and when the sonar signal processing is performed, the sonar signals are received, and the main body algorithm and the auxiliary algorithm are called to obtain the processing results. The sonar signal processing method based on a ZYNQ-7000 platform is able to perform modularization division of the MVDR direction finding algorithm, divided modules are operated in the dual-core processor and the FPGA of the platform, and the processing speed is fast and the logic source of the FPGA is saved.

The invention relates to a passive direction finding algorithm for selecting a baseline based on a phased array, and the method comprises the following steps: a), selecting a part of array elements inthe phased array to form a two-dimensional interferometer for direction finding; b), taking the direction finding result of the interferometer as the basis for determining the range of MUSIC spatialdomain search; c), completing the high-precision estimation of the pitch angle and azimuth angle through a MUSIC algorithm.

A directional multiple-polarization wide band antenna array working in a selected frequency band and including a plurality of N individual sensors of convoluted spiral type complementing a number of strands arranged according to a structure making it possible to obtain for obtaining a given azimuth coverage, each of the N sensors including a reflecting plane attached to the antenna by an insulating spacer E, matching cells suited to the working frequency band of said array, and separate output channels (5) and (7) for the vertically-polarized signals and for the horizontally-polarized signals. The antenna array also including a device suitable for executing a direction-finding algorithm that uses the amplitude and the phase of said signals and is matched to the configuration of the array.

The invention discloses an unmanned aerial vehicle signal source positioning and control system, and belongs to the technical field of unmanned aerial vehicle control. The system comprises a radio detection module, a central processing module and N positioning stations. The radio detection module comprises an antenna array, a direction finding algorithm module, a signal feature extraction module and a first communication module; each positioning station comprises a direction finding antenna, a GPS signal module, a flight control source signal locking module and a second communication module. The central processing module comprises a signal time-frequency characteristic analysis module, a control scheme decision module, a flight control source positioning algorithm module, a display controlsubsystem and a third communication module. The radio detection module realizes signal transmission with the third communication module of the central processing module through the first communication module. The central processing module realizes bidirectional signal transmission with the second communication modules of the N positioning stations through the third communication module. The system has the advantages of small interference on the surrounding electromagnetic environment, short positioning time consumption and timely and rapid taking of control measures.

The invention discloses a transformer internal partial discharge determination device and a positioning method thereof, and solves the problems that existing transformer partial discharge determination is big in error and low in performance cost; the top of a cylinder sensor mount (4) is provided with 7 ultrasonic sensor plug slots (5) and ultrasonic sensors (6) arranged in an L-shape; a spring (7) is arranged between the bottom of a cylinder groove (3) and the bottom of the cylinder sensor mount (4); an ultrasonic signal leading-out wire (8) of the ultrasonic sensor (6) is electrically connected with an ultrasonic data collector (9) through a through hole (11); the ultrasonic data collector (9) is connected with a computer (10); L-shape array sensors are employed, a wideband focusing algorithm of a total least spuares (TLS) is used for focusing partial discharge ultrasonic broadband signals, and a narrowband direction finding algorithm combining a phase match principle with cloud optimization search is used for obtaining orientation information of a partial discharge source. The transformer internal partial discharge determination device is high in direction finding precision, and accurate in positioning.

The invention discloses an SSTMV minimum variance beam forming method for wideband radar. Array data is obtained by an antenna of the wideband radar, iterative segmentation and FFT conversion are conducted on the array data to obtain array frequency domain data, and conventional beam forming treatment is conducted on the array frequency domain data through a weighting vector for conventional beamforming; sub-array division and combination are conducted on the array frequency domain data obtained after conventional beam forming treatment to obtain sub-array data; calculation and accumulation of an STCM driving covariance matrix are conducted on the sub-array data, and the beam forming of a minimum variance wideband direction-finding algorithm is conducted through the obtained STCM matrix to obtain the minimum variance beam. By means of the method, the radar space resolution capacity can be effectively improved, good performance can be presented under a small number of periods without accumulating or modifying too large number of periods due to the coherent accumulation characteristic of SSTMB, and the method greatly reduces the calculation amount of the algorithm and is suitable for the wideband radar.

The invention discloses a spatial filtering method based on direction finding equipment. The method comprises the following steps: converting a radio frequency signal received by an antenna array into an IQ data stream of each array element; calculating a covariance matrix R of the IQ data stream, and performing direction finding on the same-frequency signal of the IQ data stream by using a spatial spectrum direction finding algorithm to obtain a direction finding result; calculating actual array manifolds corresponding to the signals in all the directionsthrough the covariance matrix and the direction finding result, wherein the actual array manifolds are vectors formed by complex gains generated by the signals in all the directions in all the array elements; calculating a synthesis coefficient matrix according to the actual array manifold corresponding to the signal in each direction; and multiplying the IQ data stream of each array element by the synthesis coefficient matrix to generate a synthesis signal. According to the invention, the requirement on hardware is low; the calculation method is high in timeliness; for the synthesis coefficient of each signal, only one time of regular updating is needed; and the interference searching efficiency in radio monitoring work is improved.

The invention discloses a high-precision spatial spectrum direction finding method based on a specific non-equal-interval array structure. The method comprises the following steps: firstly, establishing a non-equal-interval array direction finding model according to an antenna given by a general-purpose aircraft; providing two direction finding schemes for different search and rescue signal frequencies in the search and rescue system, including a multi-antenna non-equal-interval linear array direction finding scheme and a double-antenna co-prime array direction finding scheme, and determining antenna array elements in the direction finding schemes; and finally, direction finding error correction is carried out, channel amplitude and phase errors in the direction finding process are analyzed, error correction is carried out by adopting a single auxiliary information source correction algorithm, and the direction finding precision in the search and rescue process is improved. According to the invention, a high-precision spatial spectrum direction finding algorithm is adopted to carry out rapid rescue and support on persons in distress, and a technical basis is provided for an emergency rescue scheme of multi-machine cooperative direction finding search and rescue.

The invention belongs to the technical field of array signal processing, and particularly relates to a fast conjugate gradient direction finding algorithm without constructing a covariance matrix, which can obviously reduce the calculation complexity under the condition of not losing precision, and is characterized in that after a radiation source signal is received, a Virnahoff equation is improved by using a least square method, a least square Winahoff equation is obtained, the least square Winahoff equation is used as a normal equation, a reference signal only related to received data is constructed by using the normal equation, an iteration initial value is set, conjugate gradient iteration is performed, a signal subspace is estimated according to an information source number, and a signal direction of arrival is acquired.

The invention discloses a method for evaluating array direction finding precision under a near-end multipath condition, and belongs to the field of array direction finding, and the method comprises the steps: constructing an array flow pattern according to an array element space arrangement position relation; setting a single signal incident wave direction; determining a reflection coefficient, an array near-end multi-path signal path, a multi-path signal quantity and a multi-path signal angle according to a relative position relationship between the antenna array and a near-end strong scatterer; describing a complex vector form of the multipath signal; synthesizing the complex vector form of the multipath signal and the incident signal vector into a synthesized signal vector form on a complex plane; and the vector form of the synthesized signal is substituted into an array direction finding algorithm, an array direction finding angle under a near-end multipath condition is simulated and calculated, the calculated angle is compared with an incident wave theoretical angle, and a direction finding error caused by a near-end multipath effect is rapidly evaluated. The method is suitable for the evaluation of the array direction finding precision under the condition that a near-end strong scatterer generates a multipath signal and the evaluation of the influence of a far-end multipath effect on the array direction finding precision, and has universality.

The invention relates to the field of array signal processing, and discloses a high-precision noise adaptive direction finding method, which comprises the following steps of: establishing a noise adaptive array direction finding model based on a uniform linear array to obtain an array receiving data vector; carrying out de-impact smoothing preprocessing on the array receiving data; carrying out noise type judgment by utilizing distribution characteristics of impact noise, and carrying out Gaussian smoothing preprocessing on the array receiving data of an impact noise background by adopting partial median filtering; calculating an array receiving data covariance matrix, and reconstructing smooth noise through the matrix; then, carrying out characteristic decomposition on the array receiving data covariance matrix to obtain a signal subspace and a noise subspace, and further eliminating noise components in the signal subspace by utilizing a subspace projection technology; and finally, carrying out direction finding by adopting an ESPRIT direction finding algorithm. The method is suitable for direction finding of impact noise and Gaussian noise at the same time, the implementation speed is high, and the method still has high direction finding precision under the strong impact noise background with the characteristic index smaller than 0.5.