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CN-121996920-A - Method, system and device for detecting and eliminating false points of vehicle millimeter wave radar caused by tire water throwing in rainy days

CN121996920ACN 121996920 ACN121996920 ACN 121996920ACN-121996920-A

Abstract

The invention relates to the technical field of intelligent driving environment perception and discloses a method, a system and a device for detecting and eliminating false points of a vehicle-mounted millimeter wave radar caused by tire water throwing in rainy days, wherein the technical scheme is characterized by comprising the following steps of calibrating basic parameters of wheels, constructing a physical model of rear wheel water throwing, and determining multidimensional theoretical characteristics and corresponding judgment thresholds of the false points of water throwing; the method comprises the steps of synchronously obtaining vehicle state data and original point cloud data of a vehicle-mounted rear angle millimeter wave radar, aligning a time stamp, executing subsequent steps when triggering water throwing detection, presetting a water throwing detection target area based on spatial distribution characteristics and a judgment threshold value of the spatial distribution characteristics, screening out the original point cloud data in the area to serve as a candidate false point set, sequentially judging other multidimensional theoretical characteristics of each point in the candidate false point set, marking points meeting all theoretical characteristic ranges as tire water throwing false points, and eliminating the tire water throwing false points from the original point cloud data.

Inventors

  • PAN HE

Assignees

  • 南京楚航科技有限公司

Dates

Publication Date
20260508
Application Date
20260408

Claims (10)

  1. 1. A method for detecting and eliminating false points of a vehicle millimeter wave radar caused by tire water throwing in rainy days is characterized by comprising the following steps: s1, calibrating basic parameters of wheels, constructing a physical model of water throwing of a rear wheel, and determining multidimensional theoretical characteristics of water throwing false points and corresponding judgment thresholds; s2, synchronously acquiring vehicle state data and original point cloud data of the vehicle-mounted rear angle millimeter wave radar, aligning a time stamp, judging whether to trigger water throwing detection, and executing S3 if triggered; s3, presetting a water-throwing detection target area based on spatial distribution characteristics of a physical model and a judgment threshold value, and screening out original point cloud data in the area to serve as a candidate false point set; s4, carrying out range judgment on each point in the candidate false point set sequentially through other multidimensional theoretical features and judgment thresholds, and marking points meeting the range of all theoretical features as tire water throwing false points; And S5, removing false water throwing points of the tire from the original point cloud data, and taking the rest point cloud data as true points.
  2. 2. The method for detecting and eliminating false points of the vehicle millimeter wave radar caused by water throwing of the tire in rainy days is characterized in that in S1, the physical model construction method for water throwing of the rear wheel is as follows: Establishing a vehicle coordinate system; On the basis of a vehicle coordinate system, on the basis of pure rolling dynamics of wheels, a ground speed vector when water drops separate from tires is defined; according to the ground speed vector when the water drops separate from the tire, the influence of air resistance and gravity on the flight track of the water drops is combined, and the multidimensional theoretical characteristics of the water throwing false points are obtained through fitting; And determining a judgment threshold value corresponding to each dimension theoretical characteristic through a real vehicle rainy day calibration test.
  3. 3. The method for detecting and eliminating false points of the vehicle millimeter wave radar caused by water throwing of the tire in a rainy day according to claim 2 is characterized in that: The ground speed vector of the water drop when the water drop breaks away from the tire is V drop =V wheel center +omega×r, wherein V wheel center is the ground speed of the wheel center of the rear wheel, R is the position vector of the water drop relative to the wheel center, omega is the angular speed of the wheel, omega=v wheel /R,v wheel is the wheel speed of the rear wheel, and R is the nominal rolling radius of the tire.
  4. 4. The method for detecting and eliminating false points of the vehicle millimeter wave radar caused by water throwing of the tire in rainy days is characterized in that the multidimensional theoretical characteristics comprise spatial distribution characteristics, radial speed characteristics, energy intensity characteristics and point cloud distribution characteristics; the space distribution feature is used for limiting the distribution space of the water throwing false points, and is only distributed in a short-distance area behind the rear wheel side and corresponds to a short-distance detection interval of the rear angle radar; The radial speed characteristic is used for limiting the association relation between the radar radial speed of the water throwing false point and the wheel speed of the rear wheel, wherein the radial speed range is 0<v r <k·v wheel , v r is the radial speed of the point cloud detected by the radar, and k is a pre-calibrated speed correction coefficient; The energy intensity characteristic is used for limiting a radar echo energy intensity interval of a water throwing false point; the point cloud distribution characteristics are used for limiting the water throwing false points to be in a discrete band-shaped and bulk distribution shape, and have the characteristics of large number of point clouds in a neighborhood, small radial velocity variance and no contour aggregation of a real target.
  5. 5. The method for detecting and eliminating false points of the vehicle millimeter wave radar caused by the water throwing of the tire in the rainy day is characterized in that in S2, vehicle state data comprise the longitudinal speed of a vehicle, the wheel speed of a left rear wheel, the wheel speed of a right rear wheel, the calibration value of the rolling radius of the tire, a wiper state signal and a road surface adhesion coefficient signal; the radar origin cloud data at least comprises radial speed, detection distance, azimuth angle, echo energy intensity and time stamp of each detection point.
  6. 6. The method for detecting and eliminating false points of the vehicle millimeter wave radar caused by water throwing of the tire in rainy days, which is characterized in that S4, radial speed characteristic judgment, energy intensity characteristic judgment and point cloud distribution characteristic judgment are sequentially carried out on each point in the candidate false point set; calculating the radial velocity v r of the candidate point, judging whether the radial velocity v r meets k 1 ·v wheel <v r <k 2 ·v wheel ,k 1 as a minimum velocity correction coefficient and k 2 as a maximum velocity correction coefficient, and entering the next judgment if the radial velocity v r meets the minimum velocity correction coefficient; Judging whether the echo energy intensity P of the candidate point meets P min <P<P max , wherein P min is the minimum detection signal-to-noise ratio of the radar, P max is the pre-calibrated maximum energy threshold of water throwing, and entering the next judgment if the echo energy intensity P of the candidate point meets the threshold; And the point cloud distribution characteristics are judged, namely the number of the point clouds and the radial velocity variance in the preset neighborhood of the candidate point are counted, and if the number of the point clouds in the neighborhood is more than or equal to a preset number threshold value and the radial velocity variance is less than or equal to a preset variance threshold value, the false point of tire water throwing is judged.
  7. 7. The method for detecting and eliminating false points of the vehicle millimeter wave radar caused by water throwing of the tire in rainy days is characterized in that S6 is executed after S5, and S6 is to adaptively calibrate and update a water throwing characteristic judgment threshold under the standard working condition without water accumulation and water throwing.
  8. 8. The method for detecting and eliminating false points of the vehicle millimeter wave radar caused by water throwing of a rainy day tire according to claim 1 is characterized in that in S3 and S4, when multi-dimensional theoretical feature matching judgment is carried out, a weighted voting mechanism is adopted to replace serial judgment, preset weights are distributed for different dimensional features, and the point with the total score exceeding a judgment threshold value is judged to be the water throwing false point.
  9. 9. A vehicle millimeter wave radar false point detection and elimination system caused by tire water throwing in rainy days is characterized by comprising the following components: The model construction module is used for recording basic parameters of the calibration wheels, constructing a physical model of water throwing of the rear wheel, and determining multidimensional theoretical characteristics of water throwing false points and corresponding judgment thresholds; the vehicle state information input module is used for acquiring vehicle state data; the back angle millimeter wave radar point cloud input module is used for acquiring original point cloud data of the vehicle-mounted back angle millimeter wave radar; The time synchronization and coordinate conversion module is used for performing time stamp alignment on the vehicle state data and the original point cloud data of the vehicle-mounted back angle millimeter wave radar, and converting the original point cloud data into a vehicle coordinate system from an RA polar coordinate system taking the radar as a center according to the angle and the position of the radar installed on the vehicle; the water-throwing ROI region of interest screening module is used for presetting a water-throwing detection target region based on the spatial distribution characteristics of the physical model and a judgment threshold value, screening out original point cloud data in the region and taking the original point cloud data as a candidate false point set; The multi-dimensional false point judging module is used for judging the range of each point in the candidate false point set through other multi-dimensional theoretical characteristics and judging thresholds in sequence, and marking the points meeting the range of all theoretical characteristics as tire water-throwing false points; the false point cloud eliminating and outputting module is used for eliminating false points of tire water throwing from original point cloud data, taking the rest point cloud data as true points and outputting the true points to the subsequent target tracking module.
  10. 10. The device for detecting and removing false points of the vehicle millimeter wave radar caused by water throwing of the tire in rainy days is characterized by comprising a processor and a memory, wherein the memory stores a computer program executable by the processor, and the method of any one of claims 1-8 is realized when the processor executes the computer program.

Description

Method, system and device for detecting and eliminating false points of vehicle millimeter wave radar caused by tire water throwing in rainy days Technical Field The invention relates to the technical field of intelligent driving environment sensing, in particular to a method, a system and a device for detecting and eliminating false points of a vehicle-mounted millimeter wave radar caused by tire water throwing in rainy days. Background The vehicle-mounted millimeter wave radar is a core sensor of an intelligent driving assistance system, particularly a rear-angle millimeter wave radar, bears core functions such as blind area monitoring (BSD), lane Changing Assistance (LCA), rear collision early warning (RCW) and the like, and the detection reliability directly determines driving safety. When the vehicle runs on a ponding road surface in a rainy day, the ponding on the road surface can be thrown out at a high speed by the rear wheels of the vehicle, so that a water curtain splashing to the rear side of the vehicle is formed. The 77GHz vehicle-mounted millimeter wave radar has high sensitivity to the reflection of an aqueous medium, a large number of water throwing point clouds with radial speed can be detected, the point clouds have continuous dynamic speed characteristics and can be mistakenly identified as real dynamic targets by a subsequent target tracking algorithm, so that frequent false alarms and false function triggering of a system are caused, and the driving experience and the driving safety are seriously affected. In the prior art, the radar false point suppression scheme has obvious technical defects aiming at static clutter, intersection fixed reflection, hurdle virtual images, general rainy day noise and other scenes: the method has the advantages that no physical model specific to a rear wheel water throwing scene exists, dynamic characteristics of tire water throwing are not combined, pertinence to water throwing false points is insufficient, and detection accuracy is low; Only relying on the characteristics of Lei Dadian cloud to judge, vehicle dynamics data (vehicle speed and wheel speed) are not fused, and a water throwing false point cannot be distinguished from a close-range real dynamic target, so that the problem of false deletion of the real target or false point omission easily occurs; the partial scheme has high calculation complexity and cannot meet the real-time requirement of the vehicle-mounted embedded platform. Therefore, it is necessary to develop a vehicle-mounted millimeter wave radar false point detection and elimination method which is specially used for a rainy day tire water throwing scene and combines a physical model and multi-source data fusion, and the problems existing in the prior art are solved. Disclosure of Invention The invention aims to provide a method, a system and a device for detecting and eliminating false points of a vehicle-mounted millimeter wave radar caused by tire water throwing in rainy days, which can pointedly solve the problem of false targets of the radar caused by water throwing of a rear wheel of a rainy day ponding road surface, have high detection accuracy, good instantaneity and strong robustness, and can effectively improve the perception reliability of the vehicle-mounted rear angle radar under the working condition of the rainy days. The technical aim of the invention is realized by the following technical scheme that the method for detecting and eliminating false points of the vehicle millimeter wave radar caused by the water throwing of the tire in rainy days comprises the following steps: s1, calibrating basic parameters of wheels, constructing a physical model of water throwing of a rear wheel, and determining multidimensional theoretical characteristics of water throwing false points and corresponding judgment thresholds; s2, synchronously acquiring vehicle state data and original point cloud data of the vehicle-mounted rear angle millimeter wave radar, aligning a time stamp, judging whether to trigger water throwing detection, and executing S3 if triggered; s3, presetting a water-throwing detection target area based on spatial distribution characteristics of a physical model and a judgment threshold value, and screening out original point cloud data in the area to serve as a candidate false point set; s4, carrying out range judgment on each point in the candidate false point set sequentially through other multidimensional theoretical features and judgment thresholds, and marking points meeting the range of all theoretical features as tire water throwing false points; And S5, removing false water throwing points of the tire from the original point cloud data, and taking the rest point cloud data as true points. As a preferable technical scheme of the invention, in S1, the method for constructing the physical model of the back wheel water throwing comprises the following steps: Establishing a vehicle coordinate system; On the ba