Method and device for measuring trailer included angle, and vehicle

Patent metadata

Field	Value
Publication number	US-12044523-B2
Application number	US-202117325151-A
Country	US
Kind code	B2
Filing date	May 19, 2021
Priority date	Nov 20, 2018
Publication date	Jul 23, 2024
Grant date	Jul 23, 2024

Abstract

The present disclosure provides a method, an apparatus and a vehicle for trailer angle measurement, applied in a semi-trailer including a tractor and a trailer. At least one LiDAR is provided on each of two sides of a rear part of the tractor. A reflector with a reflective surface is fixedly provided at a front part of the trailer, and the reflective surface faces the LiDARs. The method includes: controlling the LiDARs to emit laser light, such that the reflective surface of the reflector reflects the laser light; controlling each of the LiDARs to receive a corresponding laser point cloud reflected by the reflector; and calculating a trailer angle based on the corresponding laser point clouds. The method and apparatus can increase the range of trailer angle measurement, such that the trailer angle can be measured even if the trailer angle is relatively large.

First claim

What is claimed is:

1. A method for trailer angle measurement, applied in a vehicle comprising a tractor and a trailer, at least two LiDAR being provided on a rear of the tractor, a reflector with a reflective surface being fixedly provided at a front of the trailer, and the reflective surface facing the LiDARs, the method comprising:
controlling the LiDARs to emit laser light, such that the reflective surface of the reflector reflects the laser light emitted by the LiDARs;
controlling the LiDARs to receive laser light reflected by the reflector respectively and obtaining laser point clouds based on the laser light; and
calculating a trailer angle based on the laser point clouds.

2. The method of claim 1 , wherein the said calculating the trailer angle based on the laser point clouds comprises:
processing the laser point clouds to obtain initial trailer angles; and
screening the initial trailer angles in accordance with a predetermined determination condition.

3. The method of claim 2 , wherein the said calculating the trailer angle based on the laser point clouds further comprises:
sorting the screened initial trailer angles based on collecting times in a current collecting period to obtain angle data to be processed, wherein the collecting times are times when the LiDARs receive the laser light respectively; and
performing Kalman filter on the angle data to be processed to obtain the trailer angle of the current collecting period.

4. The method of claim 2 , wherein the said processing the laser point clouds to obtain the initial trailer angles comprises:
performing area of interest (AOI) filter on the laser point clouds to obtain AOI filtered laser point clouds within a predetermined area range, the predetermined area range being determined based on a range of motion of the reflector around the tractor; and
performing noise filter on the AOI filtered laser point clouds to obtain noise filtered laser point clouds corresponding to the LiDARs respectively.

5. The method of claim 4 , wherein the said processing the laser point clouds to obtain the initial trailer angles further comprises:
applying a random sample consensus (RANSAC) algorithm to the noise filtered laser point clouds to obtain one or more straight line segments formed by the noise filtered laser point cloud for each of the LiDARs, and determining a longest straight line segment for each of the LiDARs from the one or more straight line segments;
determining, in a LiDAR coordinate system, a straight line equation of the longest straight line segment and a number of points in the laser point cloud forming the longest straight line segment for each of the LiDARs; and
calculating a initial trailer angle based on the straight line equation of the longest straight line segment for each of the LiDARs.

6. The method of claim 4 , further comprising:
predetermining a first distance and a second distance based on the range of motion of the reflector around the tractor, the second distance being greater than the first distance;
obtaining a first circular area and a second circular area on a laser scanning plane, with projection of a rotation shaft connecting the tractor and the trailer on the laser scanning plane as a center and the first distance and the second distance as radii, respectively; and
determining an area range outside the first circular area and inside the second circular area as the predetermined area range.

7. The method of claim 5 , wherein the said screening the initial trailer angles in accordance with a predetermined condition comprises:
determining whether the number of points in the laser point cloud forming the longest straight line segment corresponding to each of the LiDARs is smaller than a predetermined number threshold; and
discarding one of the initial trailer angles corresponding to any one of the LiDARs having the number of points in the laser point cloud forming the longest straight line segment smaller than the predetermined number threshold.

8. The method of claim 5 , wherein the said screening the initial trailer angles in accordance with a predetermined condition comprises:
determining, when a current collecting period is not a first collecting period, whether an angle deviation value between each of the initial trailer angles in the current collecting period and a trailer angle obtained in a previous collecting period is greater than a predetermined angle deviation threshold respectively; and
discarding one of the initial trailer angles in the current collecting period whose angle deviation value is greater than the predetermined angle deviation threshold.

9. An apparatus for trailer angle measurement, applied in a vehicle comprising a tractor and a trailer, at least two LiDARs being provided on a rear of the tractor, a reflector with a reflective surface being fixedly provided at a front of the trailer, the reflective surface facing the LiDARs, the apparatus being communicatively connected to the LiDARs, and the apparatus comprising a memory, a processor, and a computer program stored on the memory and executable by the processor, wherein the processor is configured to, when executing the computer program, perform a process of trailer angle measurement, the process comprising:
controlling the LiDARs to emit laser light, such that the reflective surface of the reflector reflects the laser light emitted by the LiDARs;
controlling the LiDARs to receive laser light reflected by the reflector respectively and obtaining laser point clouds based on the laser light; and
calculating a trailer angle based on the laser point clouds.

10. The apparatus of claim 9 , wherein the said calculating the trailer angle based on the laser point clouds comprises:
processing the laser point clouds to obtain initial trailer angles; and
screening the initial trailer angles in accordance with a predetermined determination condition.

11. The apparatus of claim 10 , wherein the said calculating the trailer angle based on the laser point clouds further comprises:
sorting the screened initial trailer angles based on collecting times in a current collecting period to obtain angle data to be processed, wherein the collecting times are times when the LiDARs receive the laser light respectively; and
performing Kalman filter on the angle data to be processed to obtain the trailer angle of the current collecting period.

12. The apparatus of claim 10 , wherein the processing the laser point clouds to obtain the initial trailer angles comprises:
performing area of interest (AOI) filter on the laser point clouds to obtain AOI filtered laser point clouds within a predetermined area range, the predetermined area range being determined based on a range of motion of the reflector around the tractor; and
performing noise filter on the AOI filtered laser point clouds to obtain noise filtered laser point clouds corresponding to the LiDARs respectively.

13. The apparatus of claim 12 , wherein the said processing the laser point clouds to obtain the initial trailer angles further comprises:
applying a random sample consensus (RANSAC) algorithm to the noise filtered laser point clouds to obtain one or more straight line segments formed by the noise filtered laser point cloud for each of the LiDARs, and determining a longest straight line segment for each of the LiDARs from the one or more straight line segments;
determining, in a LiDAR coordinate system, a straight line equation of the longest straight line segment and a number of points in the laser point cloud forming the longest straight line segment for each of the LiDARs; and
calculating a initial trailer angle based on the

Assignees

• Beijing Tusen Zhitu Tech Co Ltd

Inventors

• Jin Yuhe
• Li Yiming
• Wu Nan

Classifications

• G01S17/89

  for mapping or imaging · CPC title

• G01S17/06

  Systems determining position data of a target · CPC title

• B62D53/00

  Tractor-trailer combinations; Road trains (traction couplings other than fifth wheel coupling B60D {; tracked vehicles comprising at least two articulated parts B62D55/0655}) · CPC title

• G01S7/4808

  Evaluating distance, position or velocity data · CPC title

• G01S17/87

  Combinations of systems using electromagnetic waves other than radio waves · CPC title