141 results about "Multipath effect" patented technology

The invention relates to the technical field of Bluetooth positioning, and discloses a Bluetooth positioning method and system based on multi-beacon RSSI weighted optimization, and the method comprises the steps: sequentially switching and scanning a broadcast signal of a target Bluetooth tag through a plurality of Bluetooth beacons disposed at a fixed position, so as to obtain a plurality of groups of RSSI measurement values from different directions; performing filtering processing on the multiple groups of RSSI measurement values to suppress signal fluctuation; calculating the weight of each beacon based on the filtered RSSI value, and constructing a weighted least square positioning model; and solving the coordinate position of the target Bluetooth tag by using a weighted least square positioning model. According to the invention, through adoption of a multi-beacon rapid switching acquisition and RSSI weighted optimization mechanism, signal quality differences of different beacons can be effectively distinguished, and dynamic weight descending processing is carried out on measurement values which are seriously interfered by a multipath effect and shielding, so that the positioning precision and stability in a complex indoor environment are remarkably improved.

The invention provides a wind power tower monitoring data dynamic compensation and fusion method for Beidou positioning, and relates to the technical field of data processing and signal processing. The method comprises the steps of obtaining original positioning data of a wind power tower, and performing data preprocessing; performing real-time analysis on the preprocessed original positioning sequence, and extracting characteristic values reflecting a multipath effect and an ionosphere delay degree; constructing a state space model, designing an adaptive module based on characteristic values, adjusting a filtering process noise matrix and an observation noise matrix in real time, and filtering the positioning data to obtain preliminary filtering data; establishing a lightweight neural network model, predicting the error compensation amount at the current moment, and compensating the preliminary filtering data; and carrying out tight coupling fusion on the compensated Beidou positioning result and high-frequency attitude data output by the IMU, and outputting a final displacement sequence. According to the method, a stable, reliable and high-precision tower drum deformation data sequence can be output.

The invention relates to the technical field of radio navigation and countering, and particularly discloses an unmanned aerial vehicle interference system and device based on phased array radar direction finding. The system comprises a phased array radar direction finding module, an environment electromagnetic propagation characteristic modeling module, an interference beam dynamic planning module and a digital beam forming interference module. Through constructing a three-dimensional electromagnetic propagation model and based on propagation loss and a multipath effect predicted by the model, a beamforming weight used for pre-compensating environmental influence is optimized and calculated, and finally an interference antenna array is driven to radiate an intelligent beam subjected to environmental pre-compensation, so that high-intensity interference is formed at an actual physical position of a target unmanned aerial vehicle, and the target unmanned aerial vehicle is subjected to environmental pre-compensation. Direction finding errors are overcome, and interference efficiency and electromagnetic compatibility are improved.

The invention relates to the technical field of computer vision, and discloses a precise medicine delivery method and system, and the method effectively strips illumination artifacts through the construction of a local gradient structure tensor field and an anisotropic screening mechanism, remarkably improves the robustness of a visual front end in a light and dark alternating environment, and improves the accuracy of medicine delivery. Rigid body motion constraint and Lie algebra continuous modeling are utilized, high-precision space-time alignment between heterogeneous sensors is realized on the premise that scene depth does not need to be recovered, hardware delay errors are eliminated, a physical-driven probability weight dynamic allocation mechanism is constructed by introducing a multipath scattering index and a structural information entropy flux, and a dynamic space-time alignment algorithm is established. Environment degradation is sensed in real time, the observation weight is adjusted in a self-adaptive mode, the influence of the non-line-of-sight multipath effect and visual texture missing is effectively restrained, high-precision inertial dead reckoning can still be maintained in a blind area where a sensor is in full failure in combination with momentum prior information generated through Schel complement marginalization operation, and the method has the advantages of being high in precision and high in precision. And the navigation continuity and reliability of the distribution robot in a complex scene are ensured.

The invention provides a high-reliability lamp mutual positioning method, system and device and a medium. The method comprises the following steps: determining a mutual influence relationship between lamps through reference parameters of the lamps with a visible light communication function in a target shopping mall during installation and working state parameters of visible light signals of the lamps; determining an interference feature vector of each lamp in the positioning process according to the mutual influence relationship, the multipath effect of the visible light signal and the interference superposition feature; determining a positioning constraint condition of each lamp, and determining a cooperative positioning parameter of each lamp through all the positioning constraint conditions and all the interference feature vectors; and determining relative positioning information of each lamp in the target shopping mall according to the anti-interference configuration parameter of the visible light signal of each lamp in the positioning process and all the cooperative positioning parameters. By adopting the scheme of the invention, the influence of the multipath effect and signal attenuation between the lamps on mutual positioning of the lamps can be reduced, so that high-reliability mutual positioning of the lamps is realized.

The invention relates to the technical field of indoor positioning, in particular to a millimeter wave CSI (Channel State Information) indoor positioning method and system based on a generative adversarial network, and millimeter waves are large in bandwidth, narrow in beam, high in time resolution and space angle resolution and capable of reducing the influence of a multipath effect. Position estimation is directly obtained from CSI data directly obtained in the millimeter wave communication process, complex signal processing and filtering steps of obtaining other parameters from CSI are avoided, and the system calculation complexity is greatly reduced. The information of the AP position is extracted from the high-dimensional observation vector by using the generative adversarial network, so that complex positioning algorithms such as Kalman filtering or graph optimization are avoided, and the calculation complexity is reduced; according to the method, AP position estimation is obtained through confrontation training of the generator and the discriminator, position coordinates of reference points do not need to serve as labels, input data are all label-free data, dependence on marked data is avoided, and prior knowledge such as the AP or the reference points is not needed.

The invention belongs to the technical field of pavement detection, and discloses a highway pavement roadbed detection method and system based on laser three-dimensional scanning. By establishing an analytic optical or radar scattering physical model, a distance measurement deviation initial value conforming to a multi-path reflection physical mechanism is provided for each laser measurement point, and then refined correction is performed on the initial value through a residual error regression network fusing local point cloud context information, so that advantage complementation of physical prior and data driving is realized, and the accuracy of distance measurement is improved. And finally, in combination with adaptive filtering based on a confidence map, ranging errors caused by a multi-path effect can be effectively distinguished and corrected in the presence of complex road surface conditions such as slippery road surface, greasy dirt or thin water film, and meanwhile, geometric details such as real road surface pits, textures and the like are completely reserved. Therefore, the reconstruction error and the disease false alarm rate of the pavement digital elevation model are obviously reduced, and the precision and the reliability of highway pavement roadbed detection are improved.

The invention relates to the technical field of unmanned aerial vehicles, in particular to an unmanned aerial vehicle positioning and orienting method, which comprises the steps of data acquisition and space-time alignment, environment feature fingerprint extraction, adaptive robust factor graph construction and dynamic covariance reweighted optimization. According to the method, the environment feature fingerprints are introduced as a prior diagnosis mechanism, GNSS non-line-of-sight propagation and visual feature depletion areas can be identified in real time, dynamic reweighting is carried out by utilizing the environment feature fingerprints on the factor graph optimization level, GNSS observation values polluted by a multipath effect or visual features with poor quality are automatically inhibited, and the accuracy and the reliability of the GNSS non-line-of-sight propagation and visual feature depletion areas are improved. Therefore, smooth seamless switching from loose coupling to tight coupling is achieved in urban canyons or indoor and outdoor transition areas, posture sudden change caused by traditional fixed threshold switching is avoided, and the positioning reliability of the system in complex electromagnetic and light environments is remarkably improved.

The invention discloses an indoor positioning track tracing and area early warning method and system, and relates to the technical field of indoor positioning, the method comprises the following steps: receiving a positioning signal, and synchronously collecting inertial navigation data of an inertial measurement unit; filtering processing is carried out on the positioning signal, non-line-of-sight interference and multipath effect interference components are identified, and interference compensation parameters are generated; after a positioning signal is calibrated by combining the parameters, real-time position coordinates are calculated; running a pedestrian dead reckoning algorithm on the basis of inertial navigation data to obtain continuous relative position coordinates, and correcting by taking the real-time position coordinates as reference to form initial movement track data; presetting an early warning area boundary and a triggering condition, and if the condition is met, starting an early warning response and recording an early warning event; and integrating the continuous real-time position coordinates, the initial movement track data and the early warning event records, and constructing a complete movement track file to realize track tracing. The system is matched with the method, the positioning reliability in the indoor complex environment can be improved, and continuous track tracing and accurate area early warning are supported.

The invention relates to the technical field of semiconductor radio frequency signal processing, and discloses a narrowband signal receiving system and method, and the system comprises a coarse frequency offset value capturing module, a carrier phase locking module, a digital domain carrier tracking module, a timing synchronization and multipath correction module, and a vector amplitude phase correction and equalization module. In the prior art, the technical problems of lock losing, judgment errors and high bit error rate caused by serious multipath interference and frequency offset drifting of narrow-band signals are difficult to solve in complex environments with multipath effect and high frequency offset, such as urban canyons, basements and warehouses. According to the invention, by introducing analog phase locking, digital fine tuning, dual-correlation symbol synchronization based on multi-path sensing and vector amplitude-phase combined compensation overall architecture with cooperation of analog and digital, the problems of synchronization failure and demodulation performance reduction caused by multi-path distortion in the prior art are avoided; and the sensitivity and the overall reliability of radio frequency signal receiving are remarkably improved.

The invention relates to the field of unmanned aerial vehicles, in particular to an unmanned aerial vehicle autonomous fixed-point landing control method based on an ultrasonic array algorithm, and the method comprises the steps: dividing the landing process of an unmanned aerial vehicle into a normal flight stage, a deceleration approaching stage and a near-ground landing stage, starting an ultrasonic beacon array in the approaching flight stage, and confirming the availability of a landing point; a horizontal azimuth angle, a yaw angle and a relative distance are calculated in real time in a deceleration approach stage to perform landing guidance, direct waves and multi-path reflection signals are analyzed in a near-earth landing stage, characteristic parameters such as time delay inequality and phase offset are extracted, an environment reflection space model is reversely constructed, then positioning correction is calculated, a pose fine adjustment instruction is generated, and the attitude fine adjustment instruction is subjected to attitude fine adjustment. And precise fixed-point landing of the unmanned aerial vehicle is realized. According to the method, high-precision positioning is kept under complex environment disturbance, and the stability, accuracy and efficiency of fixed-point landing of the unmanned aerial vehicle in a complex environment are improved by converting the multipath effect from an interference source to available positioning information.

The invention relates to the technical field of geodetic surveying instruments and geological disaster monitoring, and discloses a geological environment displacement surveying system based on a GNSS multipath effect, and the system comprises a signal collection unit which is used for receiving a satellite signal and extracting a signal-to-noise ratio sequence; the interference feature separation unit is used for stripping a direct signal power component and generating a residual oscillation sequence; the geometric inversion calculation unit is used for generating a reference interferometric phase template in a height search domain, and generating a height-correlation map to lock the current vertical height by calculating and superposing correlation coefficients between the residual oscillation sequence and the reference interferometric phase template; according to the invention, through a spatial domain geometric matching mechanism, high-precision distance measurement is realized in a complex environment in which a satellite visual segmental arc is broken, dependence of a traditional spectral analysis method on observation duration is broken through, and signal-to-noise ratio data endogenesis is utilized to decouple observation station attitudes and environmental medium attributes. And the stability and the multi-dimensional perception capability are improved.

The invention relates to the technical field of radar signal processing, and discloses an anti-multipath interference vehicle-mounted millimeter wave radar signal processing method, and the method comprises the steps: obtaining a radar echo signal, and decomposing the radar echo signal into a plurality of overlapped sub-band signals in a frequency domain; constructing a static environment Doppler manifold curved surface by using self-vehicle motion data, and calculating a theoretical phase evolution model according to the static environment Doppler manifold curved surface; extracting an actual measurement phase difference between the sub-bands, and carrying out coherent accumulation on the actual measurement phase difference and the theoretical model to generate a manifold consistency coherence coefficient; direction-of-arrival estimation is carried out on each sub-band signal, and the spatial spectrum drift statistical dispersion of an angle estimation value is calculated; and generating a target multipath confidence score according to the manifold consistency coherence coefficient and the spatial spectrum drift statistical dispersion, and executing a suppression decision on a radar detection target. According to the invention, by introducing a kinematics physical constraint and broadband space stability detection mechanism, false targets generated by a multipath effect are effectively identified and eliminated, and the environmental perception precision and robustness of the vehicle-mounted radar are improved.

The application discloses a marine buoy multi-source fusion positioning method and system based on a factor graph optimization, which acquires GNSS observation data, IMU measurement data and marine environment auxiliary data; a factor graph containing state nodes, GNSS position factors, IMU pre-integration factors and marine dynamics constraint factors is constructed, and wave and current theories are used to constrain buoy movement; in view of multipath effects, marine surface reflection geometry and marine root mean square wave height are combined to calculate a multipath weighting factor, and a GNSS covariance matrix is adaptively adjusted; according to IMU data, a sea state level is discriminated, and an edge window length and a trigger interval of incremental smoothing solving are adaptively linked and adjusted; through adjacent buoy ranging information, collaborative constraints are constructed, and based on Mahalanobis distance and chi-square distribution threshold value detection, abnormalities are detected and local reconstruction is performed. The application effectively suppresses marine surface multipath interference, slows down the accumulation of calculation errors during signal interruption, and realizes high-availability continuous positioning under limited computing power.

This invention discloses a dual-frequency circularly polarized fusion antenna with a high frequency ratio and its design method. It includes a first and a second dielectric substrate, with the first substrate positioned above the second. The lower surface of the first substrate is a copper-clad ground plane, and its upper surface is provided with a first, second, third, and fourth metal radiator. A metal post is loaded at one end of each radiator near the center of the dielectric substrate and connected to the ground plane, while a millimeter-wave metal probe is loaded at the other end away from the center. The lower surface of the second dielectric substrate has a microwave feed network and four 180-degree phase difference power dividers. The output ports of the microwave feed network are connected to the four microwave metal probes, and the output ports of the 180-degree phase difference power dividers are connected to eight millimeter-wave metal probes. This invention features dual-frequency circular polarization, effectively reducing the impact of multipath effects and enabling the reuse of radiators, thereby reducing the space resource requirements of communication equipment.

The invention discloses a real-time centimeter-level land survey delimitation lofting method and device based on Beidou third generation, and belongs to the technical field of land survey delimitation. According to the method, the problems that the precision is reduced and even operation cannot be carried out due to satellite signal lock losing or multipath effect in a complex environment in the prior art are solved, high-shielding risk points are recognized in advance by simulating Beidou signal propagation and calculating the signal shielding probability, an alternative calibration point position set is generated for the high-shielding risk points, and the accuracy of the high-shielding risk points is improved. Accurate lofting can still be ensured in a complex environment; an optimal operation path is generated according to the spatial relation graph, and the moving distance and time of the mobile equipment are reduced by combining the reasonability of a lofting logic sequence; and in the lofting process, the control terminal monitors the positioning environment in real time and intelligently calls a plan with concentrated alternative calibration point positions, so that complex conditions such as signal shielding are effectively handled, the continuity and reliability of lofting work are ensured, and the efficiency of survey and delimitation work is improved.

The application relates to the cross-technology field of satellite navigation and wireless positioning technology, in particular to a real-time dynamic high-precision positioning method based on tight coupling of Beidou and UWB, solves the problem that error coupling in Beidou and UWB observation data is not fully solved in the prior art, and in particular under a high-speed dynamic scene, the mutual influence of Beidou receiver clock error, UWB base station clock error and multipath error leads to continuous accumulation of errors, and the positioning precision is significantly reduced. A real-time dynamic high-precision positioning method based on tight coupling of Beidou and UWB comprises a data preprocessing and space-time alignment module, an error joint estimation model, a rapid ambiguity fixing algorithm, a geometric constraint enhanced positioning engine module and a dynamic coordinate conversion and fusion output module. The method disclosed in the application adopts a highly integrated multi-model Kalman filter architecture to realize synchronous and accurate compensation of Beidou receiver clock error, UWB base station time delay and multipath effect.

The application provides a method and device for determining wide-lane integer ambiguity, electronic equipment and VRS system. After the first single-difference wide-lane float ambiguity of a satellite is calculated, the trend error of the single-difference wide-lane float ambiguity is used to correct the first single-difference wide-lane float ambiguity, so as to reduce the error caused by the multipath effect on the first single-difference wide-lane float ambiguity. The corrected first single-difference wide-lane float ambiguity is used to determine the wide-lane integer ambiguity of the satellite in the first time period, so as to suppress the influence of the multipath effect on the observation accuracy of the reference station, improve the correctness of the calculated wide-lane integer ambiguity, and further improve the accuracy of the subsequent positioning and other related calculations through the wide-lane integer ambiguity.

This invention belongs to the field of vision and image processing technology, and provides a method, system, device, and medium for detecting dangerous actions based on radio frequency (RF) images. The method includes: acquiring a monocular video stream of a target scene, reconstructing a three-dimensional digital space geometric model of the target scene, and solving the pose matrix; collecting raw multidimensional feature data emitted by a signal transmitting device, mapping the raw multidimensional feature data to the three-dimensional digital space geometric model, and generating a three-dimensional scalar field data volume characterizing human radio frequency behavior disturbances; calculating a dynamic disturbance residual field based on the three-dimensional scalar field data volume, projecting and encoding the dynamic disturbance residual field to generate a 2.5D multi-channel human radio frequency behavior feature image, and identifying dangerous actions. This invention utilizes monocular vision to reconstruct a three-dimensional digital space and solve the pose of RF devices, establishing a physical space-digital space mapping relationship, and eliminating the strong dependence of traditional RF solutions on specific room layouts and multipath effects.

The invention provides a sea surface UWB positioning data precision improvement method based on EKF and LSTM fusion, and the method inhibits NLOS errors and multipath effects through the physical model constraint of EKF and the time sequence feature learning capability of LSTM, and improves the positioning precision in a complex sea surface environment. A positioning framework combining data driving and a physical model is designed, long-term stable positioning in a dynamic environment is achieved, and the problems of error accumulation and poor adaptability of an existing method are solved; an integrated positioning system is constructed, the whole-process high-precision processing from data acquisition, filtering, prediction to result fusion is realized through modular design, and the requirement of ocean engineering for positioning precision is met. According to the method, the NLOS error and the multipath effect are effectively inhibited, the problem that an existing method is poor in dynamic environment adaptability is solved, the software algorithm is high in transportability, and the method is suitable for actual scenes such as ship navigation and ocean search and rescue and has remarkable engineering application value.

The application discloses a wireless optical transmission method based on asymmetric clipping optical affine frequency division multiplexing, and relates to the technical field of wireless communication. The method comprises the following steps: S1, pre-processing input signal data, including mapping, design of modulation symbols and symmetry construction, to generate a frequency domain signal; S2, mapping the frequency domain signal to a time domain based on a real number discrete affine Fourier transform to generate an affine frequency division multiplexing (AFDM) signal; S3, asymmetrically clipping the AFDM signal, transmitting the AFDM signal to a receiving end through an optical communication channel, and inversely restoring the AFDM signal, including recovering the clipped signal and demodulating data; and S4, designing a real number DAFT kernel function, deducing a new c1 parameter range, realizing complete separation of signal paths with different delays in the DAFT domain, and achieving full diversity. The application solves the signal distortion problem caused by the multipath effect in optical communication.

The application relates to the technical field of indoor positioning, in particular to an indoor personnel positioning method and system based on multi-modal perception. The application proposes the following scheme: by acquiring the ultra-wideband channel impulse response, millimeter wave radar data and thermal imaging data of each layer, combining building information for double-base geometric mapping, reconstructing an indoor ray path and generating an occupancy grid map. Further, the water mist distribution intensity generated by a spraying device is collected, phase correction and beam domain purification are performed on the millimeter wave data, and flow direction filtering and flicker suppression are performed on the thermal imaging data to obtain pretreatment data. On this basis, motion prior information and boundary constraint information are extracted, and fusion is realized through mass conservation update and normalization synthesis in the occupancy grid map, and finally the position information and motion direction of the object to be positioned are output. The application can maintain positioning stability and accuracy under the interference of fire smoke, water mist and multipath effect, and is suitable for high-risk scenes such as fire rescue.

The invention relates to a communication method and device, a storage medium, communication equipment and a chip. The method comprises the following steps: firstly, a terminal is positioned through Bluetooth multiple antennas, and the relative position between the terminal and network equipment is obtained; and then the terminal performs directional MIMO WiFi communication with the network device based on the relative position with the network device. Through application of the technical scheme of the invention, directional signal transmission can be carried out between the terminal and the network equipment, the interference of a multipath effect can be reduced, and the WiFi communication quality can be improved. And compared with the transmission of omnidirectional signals, the method adopts a directional signal transmission mode, so that the signal transmitting power in an MIMO communication scene can be reduced, and the purposes of saving power and optimizing the network experience of a user are achieved.

This invention discloses a method and system for processing terminal security information in wireless networks, relating to the field of terminal security information technology. The method includes collecting a physical layer feature set and an internal state feature set of the terminal; preprocessing the features using a lightweight edge computing module; arranging the physical layer feature set in chronological order to construct sequential data; recursively calculating the mean and variance of the features to generate a real-time feature baseline range; combining the terminal's internal state feature set with a weighted correction of the real-time feature baseline range to obtain a dynamic baseline range; triggering an alarm based on the dynamic baseline range; triggering re-authentication; and after three consecutive alarm triggers, feeding back to the LSTM model for online updating. This method overcomes the limitations of traditional single-feature authentication, avoids the misjudgment of legitimate signals as abnormal due to multipath effects, reduces the false positive rate through dynamic threshold adjustment, and reduces redundant operations by 30%.

The application provides an indoor positioning method and system based on multi-modal data fusion of RMLICT. First, in the mapping stage, a fingerprint map is constructed from unbalanced crowd-sourced trajectory data. In the offline stage, trajectory data enhancement, dimension reduction and clustering processing are performed. In the online positioning stage, direction matching filtering is performed first, and then enhanced particle filtering is used to establish the mapping relationship between the RSS signal and single-step motion. This method optimizes data preprocessing and uses advanced particle filtering algorithms, which not only improves the positioning accuracy and robustness, but also significantly improves the real-time performance of the system, and is suitable for various complex indoor environments, such as scenes with severe multipath effect and signal obstruction.

The invention discloses an STM32-based multi-communication technology fusion unmanned vehicle digital twin positioning system, and aims to solve the problems of insufficient positioning precision and difficulty in multi-communication technology integration caused by a multi-path effect and non-line-of-sight propagation in a complex industrial environment. The system adopts a hardware layer double-board modular design, integrates UWB, GPS / BD dual-mode satellites, IMU (MPU6050), electronic compass (QMC5883), WiFi / BT and NB-IoT modules, guarantees signal integrity and electrical isolation through PCB optimization and multi-stage LDO voltage stabilization, and constructs a multi-source sensor fusion hardware basis. According to the system, a unique digital ID of equipment is established based on an industrial internet identification analysis system to realize cross-domain secure transmission of data, an electromagnetic path is rehearsed by using a ray tracing technology based on a digital twin closed-loop optimization mechanism, multi-domain characteristic differences of physical and virtual signals are extracted through wavelet transform, and optimal position estimation is output in combination with Bayesian inference. And meanwhile, an A * / D * Lite algorithm is adopted to realize dynamic path planning and obstacle avoidance. A four-layer architecture including a hardware layer, a network layer, a data layer and an application layer is integrally constructed, and real-time interaction of a physical entity and a virtual model and iterative optimization of a positioning result are realized. The system improves the positioning precision of complex scenes, effectively inhibits multipath interference, improves the reuse rate of hardware resources, and is suitable for the high-precision positioning requirements of unmanned vehicles in the fields of intelligent logistics, industrial automation and the like.

The invention relates to the technical field of industrial wireless remote control, and discloses a UWB feed-forward type transmitting power self-adaptive adjusting device and method and an industrial wireless remote controller, bidirectional distance measurement is executed through a UWB module, the linear distance between the remote controller and controlled equipment is obtained in real time, and the distance change rate of the linear distance is obtained; constructing a power feed-forward prediction model taking the linear distance as main disturbance input and the distance change rate as disturbance change trend input; continuously and smoothly adjusting the transmitting power between preset minimum transmitting power and maximum transmitting power before the channel quality is deteriorated based on the predicted channel quality change trend in combination with the motion state, the battery electric quantity and the shielding condition so as to match the predicted channel attenuation; a received signal strength indication RSSI value of wireless communication between a remote controller and a controlled device is synchronously collected, fusion calibration is carried out on the RSSI value and a linear distance obtained in real time, and measurement errors caused by a multipath effect and instantaneous interference in a complex industrial environment are dynamically corrected.

This invention relates to a method for improving the accuracy of UWB positioning data, belonging to the field of precise positioning technology in mines. Specifically, the method involves: setting a noise threshold and an empirical medium constant at the positioning receiver, while the positioning system receives the positioning signal; determining whether multipath effects exist in the received signal; if multipath effects exist, calculating the probability PT of no direct path extraction, and using PT to determine whether a direct path is not extracted due to an excessively high noise threshold; the positioning algorithm performs positioning calculations on the successfully extracted direct paths to obtain positioning coordinates (x0, y0, z0); and feeding the positioning coordinates (x0, y0, z0) into a Kalman filter algorithm for filtering to obtain the filtered result (x0, y0, z0). n+1 ,y n+1 ,z n+1 By comparing (x0, y0, z0) and (x n+1 ,y n+1 ,z n+1 The system determines whether the current positioning data is reliable; if the positioning data is reliable, the positioning value is optimized using Kalman filtering, and the current positioning ends. This invention can improve the accuracy and reliability of UWB positioning data, and improve the precision of underground mine positioning.

This invention discloses a method for extracting radio frequency fingerprints of broadband signals based on nonlinear features, comprising the following steps: extracting all preamble symbol groups from the received signal frame and performing preprocessing; constructing a matrix using the known preamble signal to obtain the vector value of the nonlinear coefficient mixed with multipath propagation; eliminating multipath effects based on the vector value to obtain a fingerprint value containing only nonlinear features; obtaining the nonlinear feature value of the mixture of nonlinear coefficient and local preamble based on linear convolution rules; and combining the above values ​​containing only nonlinear coefficients with the values ​​of the mixture of nonlinear coefficient and local preamble to provide a reliable transmitter identification method as a nonlinear fingerprint. The radio frequency fingerprint extraction method proposed in this invention is less affected by channel conditions and has high feature dimension scalability, thus providing a technical means for high-precision transmitter identification using radio frequency fingerprinting technology.

The invention provides an unmanned sweeper indoor positioning method based on UWB and IMU. The method comprises the following steps: acquiring UWB base station deployment information of an indoor environment, UWB ranging data of an unmanned sweeper and IMU motion parameters; based on the UWB base station deployment information, performing fusion positioning operation on the UWB ranging data and IMU motion parameters to generate a positioning result; according to the method, the coupling error of the UWB multipath effect and IMU drift is effectively solved, the motion state is accurately modeled through federated filtering, high-confidence centimeter-level positioning is realized in combination with map periodic correction, compared with a traditional scheme, the error is greatly reduced, the problems of path offset, missing sweeping or repeated sweeping are thoroughly avoided, and a reliable position reference is provided for path planning.