CN-121978719-A - Multi-sensor performance consistency comprehensive evaluation method

CN121978719ACN 121978719 ACN121978719 ACN 121978719ACN-121978719-A

Abstract

The application provides a multi-sensor performance consistency comprehensive evaluation method which comprises the steps of determining coverage distribution of intermodulation products in a UWB receiving frequency band, identifying interference intensity level according to overlapping degree of the coverage distribution of the intermodulation products and the UWB receiving frequency band, identifying intermodulation interference of a global navigation satellite system when the interference intensity is higher than a preset interference threshold value, acquiring an original packet loss event record when intermodulation interference of the global navigation satellite system exists, identifying an event with the coincidence of the occurrence time of the packet loss event and the amplitude sudden increase time of the intermodulation products, marking the event as a false packet loss event, separating the false packet loss event from the original packet loss event record, and counting UWB packet loss rate again after cleaning the packet loss event record.

Inventors

CHEN RIFU
WU DAOGUO

Assignees

国恒智能科技(惠州)有限公司

Dates

Publication Date: 20260505
Application Date: 20260309

Claims (10)

1. A method for comprehensively evaluating performance consistency of multiple sensors, the method comprising: Determining coverage distribution of intermodulation products in a UWB receiving frequency band; identifying the interference intensity level according to the overlapping degree of intermodulation product coverage area distribution and UWB receiving frequency bands, and identifying the intermodulation interference of the global navigation satellite system when the interference intensity is higher than a preset interference threshold value; When intermodulation interference of the global navigation satellite system exists, acquiring an original packet loss event record, and identifying an event of which the occurrence time of the packet loss event is identical with the intermodulation product amplitude sudden increase time, wherein the event is marked as a false packet loss event; separating false packet loss event from original packet loss event records, and counting UWB packet loss rate again after cleaning the packet loss event records; Comparing the re-counted UWB packet loss rate with a joint positioning consistency evaluation standard, wherein the UWB packet loss rate is lower than the allowable upper limit of the consistency evaluation standard, and adjusting the packet loss judgment threshold to be matched with the interference intensity level to obtain an optimized packet loss judgment threshold; The method comprises the steps of obtaining UWB sensitivity test results when the acquisition bandwidth of the global navigation satellite system is enlarged, filtering the UWB sensitivity test results by applying an optimized packet loss judgment threshold, evaluating the performance consistency of multiple sensors, obtaining evaluation deviation elimination confirmation, and generating a performance consistency evaluation report of the multiple sensors.
2. The method for integrated evaluation of performance consistency of multiple sensors according to claim 1, wherein said determining coverage distribution of intermodulation products in UWB receiving frequency bands comprises: Scanning local oscillation signals of a global navigation satellite system, and recording leakage power values of the local oscillation signals; monitoring the carrier center frequency and the received signal strength in the ultra-wideband working frequency band, and obtaining the ultra-wideband carrier power spectrum density distribution; Calculating the frequency position of a third-order intermodulation product according to the local oscillator leakage power value and the ultra-wideband carrier power spectral density, and determining the frequency point distribution of the intermodulation product in an ultra-wideband receiving frequency band; extracting an intermodulation product amplitude value, and marking intermodulation products exceeding a preset threshold value; Counting the frequency domain occupation width of the intermodulation products in the ultra-wideband receiving frequency band, judging to fall into the band if the center frequency point deviates from the ultra-wideband channel center frequency to be smaller than a preset frequency offset threshold value, and accumulating the power spectrum density value of the in-band intermodulation products; And calculating average power density through the ratio of the accumulated value to the receiving bandwidth, and determining coverage area distribution.
3. The method for comprehensively evaluating the performance consistency of multiple sensors according to claim 1, wherein the identifying the interference intensity level according to the overlapping degree of the intermodulation product coverage area distribution and the UWB receiving frequency band, and identifying the existence of intermodulation interference of the global navigation satellite system when the interference intensity is higher than a preset interference threshold value comprises: Extracting the initial frequency and the termination frequency of intermodulation products in a frequency domain, comparing the initial frequency and the termination frequency with the boundary frequency of an ultra-wideband receiving frequency band, and determining an overlapped frequency band; Calculating the bandwidth value of the overlapped frequency band, and reading the power density value of each frequency point in the overlapped frequency band; Obtaining average power density in the overlapped area by accumulating the power density values and dividing the power density values by the bandwidth values; Comparing the average power density with a preset sensitivity threshold to determine an interference intensity level; If the interference intensity level is higher than a preset interference threshold, generating an intermodulation interference existence identification signal, and recording the interference occurrence time and the overlapping frequency band range.
4. The method for comprehensively evaluating the performance consistency of multiple sensors according to claim 1, further comprising the steps of acquiring frequency positions and amplitude variation tracks of intermodulation products, acquiring frequency distribution and duration of other interference sources in a UWB working environment, analyzing response speed of the amplitude of the intermodulation products along with the change of local oscillation power of a global navigation satellite system, evaluating the coincidence degree of the frequency positions of the intermodulation products and the local oscillation frequency multiple relation, and identifying the difference of the intermodulation products and the environmental noise in the frequency spectrum purity.
5. The method for comprehensively evaluating the performance consistency of multiple sensors according to claim 1, wherein when intermodulation interference exists in a global navigation satellite system, acquiring an original packet loss event record, identifying an event of which the occurrence time of the packet loss event is identical with the amplitude sudden increase time of intermodulation products, and marking the event as a false packet loss event, wherein the method comprises the following steps: Reading an original packet loss event record from a packet loss statistics module of the UWB receiver, and extracting an occurrence time stamp and a received signal strength value of each packet loss event; Acquiring a time sequence of intermodulation product amplitude exceeding an interference threshold value from intermodulation interference judging results of the global navigation satellite system; aiming at the time stamp of each packet loss event, searching intermodulation amplitude sudden increase time which is different from the packet loss time by less than a preset time interval in the time sequence; If the intermodulation amplitude sudden increase event with the time difference within the preset time interval exists, judging that the packet loss event and intermodulation interference have a time coincidence relation; further verifying the packet loss event with the time coincidence relation, comparing the UWB signal receiving state change before and after the time, and if the UWB base station signal intensity before and after the packet loss is kept stable and antenna shielding does not occur, confirming that the packet loss is caused by intermodulation interference, and marking the packet loss event as a false packet loss event.
6. The method for comprehensively evaluating the performance consistency of multiple sensors according to claim 1, further comprising the steps of acquiring an antenna attitude angle and a shielding object distance when packet loss occurs each time from an original packet loss event record, acquiring the number of UWB signal propagation paths and reflection surfaces at the packet loss time, analyzing the time coincidence degree of the packet loss event and the shielding time of a mobile object, evaluating the association degree of the packet loss event and the indoor multipath reflection intensity change, and identifying a packet loss event set caused by the sudden increase of the amplitude of intermodulation products.
7. The method for comprehensively evaluating the performance consistency of multiple sensors according to claim 1, wherein the step of separating false packet loss events from original packet loss event records, and re-counting UWB packet loss rate after cleaning the packet loss event records comprises the steps of: Traversing the original packet loss event record, and comparing the marked false packet loss event; If a certain packet loss event is marked as false, removing the packet loss event from the record, and reserving the real packet loss event to obtain a cleaned record; Counting the total number of the residual packet loss events according to the cleaned records; Acquiring the total transmission number of ultra-wideband data packets in a test period; And dividing the total number of the remaining packet loss events by the total number of data packet transmission, and calculating the ultra-wideband packet loss rate of the re-statistics.
8. The method for comprehensively evaluating the performance consistency of multiple sensors according to claim 1, wherein the comparing the re-counted UWB packet loss rate with the joint positioning consistency evaluation standard, the UWB packet loss rate being lower than the upper allowable limit of the consistency evaluation standard, adjusts the packet loss decision threshold to adapt to the interference intensity level, and obtains an optimized packet loss decision threshold, comprises: Comparing the magnitude relation between the re-counted UWB packet loss rate and the allowable upper limit value; if the UWB packet loss rate is lower than the allowable upper limit value, calculating a difference value between the packet loss rate and the upper limit value; determining the adjustment amplitude of a packet loss judgment threshold according to the ratio of the difference value to the interference intensity level; and modifying the original packet loss judgment threshold value according to the adjustment amplitude to obtain an optimized packet loss judgment threshold.
9. The method for comprehensively evaluating the performance consistency of multiple sensors according to claim 1, further comprising the steps of analyzing the phenomenon that the positioning accuracy of the GNSS sensors still keeps a qualified range when the packet loss rate of the UWB sensors exceeds the standard, evaluating the time sequence corresponding relation of the synchronous rising of the packet loss rate of the UWB sensors after the acquisition bandwidth of the GNSS sensors is enlarged, determining the opposite performance of the performance reduction of the UWB sensors and the performance improvement of the GNSS sensors in the time dimension, and identifying the performance trend contradiction of the two types of sensors in an evaluation report.
10. The method for comprehensively evaluating the performance consistency of multiple sensors according to claim 1, wherein the steps of obtaining the UWB sensitivity test result when the acquisition bandwidth of the global navigation satellite system is enlarged, applying an optimized packet loss decision threshold to filter the UWB sensitivity test result, evaluating the performance consistency of multiple sensors, obtaining evaluation deviation elimination confirmation, and generating a performance consistency evaluation report of multiple sensors comprise: Acquiring UWB sensitivity test data when the acquisition bandwidth of the global navigation satellite system is enlarged; Screening the UWB sensitivity test data by applying the optimized packet loss judgment threshold, removing abnormal data points caused by intermodulation interference, and obtaining a filtered UWB sensitivity test result set; Determining the actual sensitivity of the UWB according to the filtered test result set; acquiring positioning precision deviation values of a global navigation satellite system and UWB, and determining a multi-sensor performance consistency score by comparing positioning coordinate differences of the two types of sensors at the same moment; Calculating the difference between the positioning precision improvement value after the bandwidth expansion of the global navigation satellite system and UWB precision loss caused by intermodulation interference based on the performance consistency score and the positioning precision deviation value of each sensor to obtain a net contribution value; and integrating the UWB real sensitivity, the consistency score, the net contribution value and performance indexes for eliminating intermodulation interference influence to generate a multi-sensor performance consistency evaluation report.

Description

Multi-sensor performance consistency comprehensive evaluation method Technical Field The invention relates to the technical field of information, in particular to a multi-sensor performance consistency comprehensive evaluation method. Background In a multi-sensor fusion positioning system, comprehensive evaluation of performance consistency of each sensor is important, because positioning stability and reliability of the whole system in a complex environment are directly determined. Global navigation satellite system and ultra wideband positioning technology are often used in combination as two core sensors to achieve indoor and outdoor seamless positioning. However, when the performance of the two types of sensors is evaluated at the same time, a phenomenon that the evaluation results are contradictory to each other often occurs, resulting in that the overall performance of the system cannot be accurately judged. Current evaluation methods typically test the global navigation satellite system and the ultra-wideband sensor separately, for example, measuring the acquisition bandwidth of the global navigation satellite system and the sensitivity and packet loss rate of the ultra-wideband system, respectively. Although the methods can independently reflect the characteristics of a single sensor, the mutual influence of radio frequency signals generated when two sensors simultaneously work in the same device is ignored. This effect can cause cross-interference with the otherwise independent performance indicators, resulting in distortion of the evaluation results. The core difficulty is that intermodulation products are easily generated between leakage of local oscillation signals of the global navigation satellite system and ultra-wideband carrier signals. When the acquisition bandwidth of the global navigation satellite system is enlarged, the local oscillation leakage power is changed, and the frequency position and the amplitude of intermodulation products are correspondingly offset. These intermodulation products are similar to spurious signals in radio frequency circuits, and when the global navigation satellite system expands the acquisition bandwidth in order to improve the outdoor signal acquisition capability, the local oscillator leakage power fluctuates with it, resulting in an offset in the frequency position and amplitude of the intermodulation products. If these products fall into the ultra wideband operating band, such as when the ultra wideband pulse signal originally used for accurate positioning is submerged in an indoor dense multipath environment, signal demodulation fails. In practical testing scenarios, this interference is particularly troublesome. For example, in a typical indoor and outdoor transition test environment, expanding the bandwidth of the gnss system should increase the satellite signal acquisition efficiency and the positioning update rate, but the ultra wideband packet loss rate is unexpectedly increased sharply, because part of the data packets cannot be decoded correctly due to intermodulation noise. When the tester counts the packet loss rate, it is unable to distinguish which packet loss is caused by the multipath fading or antenna shielding problem of the ultra wideband, and which is caused by the leakage interference of the global navigation satellite system. The confusion further amplifies the assessment contradiction, and the global navigation satellite system performs excellently in the outdoor dominant scene, but ultra-wideband performance is turned straight down when switching to indoor, resulting in low consistency score. Similar problems also occur in high dynamic scenarios, such as navigation devices, where vibrations and temperature variations exacerbate local oscillator leakage, making intermodulation interference less stable. Disclosure of Invention The invention provides a multi-sensor performance consistency comprehensive evaluation method, which mainly comprises the following steps: Determining coverage distribution of intermodulation products in a UWB receiving frequency band; identifying the interference intensity level according to the overlapping degree of intermodulation product coverage area distribution and UWB receiving frequency bands, and identifying the intermodulation interference of the global navigation satellite system when the interference intensity is higher than a preset interference threshold value; When intermodulation interference of the global navigation satellite system exists, acquiring an original packet loss event record, and identifying an event of which the occurrence time of the packet loss event is identical with the intermodulation product amplitude sudden increase time, wherein the event is marked as a false packet loss event; separating false packet loss event from original packet loss event records, and counting UWB packet loss rate again after cleaning the packet loss event records; Comparing the re-counted UWB packet