CN-122003350-A - Vehicle guidance using IMU and radar with reflective targets located on or near a driving surface

Abstract

An apparatus for guiding a land vehicle along a path on which one or more side targets having different radar reflectivity characteristics than the path are present. The apparatus includes a radar sensor, a processor, and an Inertial Measurement Unit (IMU). The radar sensor is mounted to the vehicle and is configured to radiate one or more signals to the path, the signals having a main beam pattern center pointing toward the ground and laterally from the vehicle. The radar sensor is further configured to detect one or more reflected signals from one or more side targets along the path. The processor is configured to determine a lateral distance between the vehicle and a side target based on the reflected signal when the vehicle passes or first encounters the side target. The IMU is configured to determine a change in lateral position of the vehicle between the side targets.

Inventors

• R. Bischel

Assignees

• 车辆雷达制导有限责任公司

Dates

Publication Date

20260508

Application Date

20241010

Priority Date

20231010

Claims (20)

1. 1. An apparatus for guiding a land vehicle along a path on which one or more side targets exist, the side targets having different radar reflectivity characteristics than the path, the apparatus comprising: A radar sensor mounted to the vehicle and aimed downward and toward a side of the vehicle, wherein the radar sensor is configured to radiate one or more signals having a main beam pattern center toward the ground and laterally from the vehicle via at least one transmitter to the path, wherein the radar sensor is further configured to detect one or more reflected signals from one or more of the side targets along the path via one or more receive antennas; A processor operatively connected to the radar sensor, wherein the processor is configured to determine a lateral distance between the vehicle and the side target based on the reflected signal when the vehicle passes or first encounters the side target, and An inertial measurement unit configured to determine a change in lateral position of the vehicle between the side targets.
2. 2. The apparatus of claim 1, wherein the radar sensor operates in a frequency range from about 300MHz to about 1 THz.
3. 3. The apparatus of claim 2, wherein the radar sensor operates in a frequency range from about 77GHz to about 81 GHz.
4. 4. The apparatus of claim 1, wherein the radar sensor is a frequency modulated continuous wave radar transceiver.
5. 5. The apparatus of claim 1, wherein the radar sensor is an ultra wideband pulse radar transceiver.
6. 6. The apparatus of claim 1, wherein the type of radar sensor is selected from the group consisting of dual frequency phase difference radar, multi-frequency phase radar, orthogonal frequency division multiplexing radar, frequency shift keying radar, digitally code modulated radar, phase modulated continuous wave radar, multiple input multiple output radar, polarized radar, dual polarized radar, monopulse radar, noise radar, and interferometric synthetic aperture radar.
7. 7. The apparatus of claim 1, wherein the radar sensor is single-station.
8. 8. The apparatus of claim 1, wherein the radar sensor is transceiver-specific.
9. 9. The apparatus of claim 1, wherein the radar sensor comprises an antenna array.
10. 10. The apparatus of claim 1, wherein the radar sensor is configured to transmit polarized radar signals.
11. 11. The apparatus of claim 10, wherein the radar sensor is configured to detect the reflected signal based on its polarization.
12. 12. The apparatus of claim 1, wherein the radar sensor is configured to be placed on or within a front bumper of the vehicle.
13. 13. The apparatus of claim 1, wherein the radar sensor is packaged within a vehicle light assembly.
14. 14. The apparatus of claim 1, wherein the processor is configured to process only a portion of the reflected signal received in a window corresponding to a desired range of the reflected target.
15. 15. The apparatus of claim 1, wherein the processor is configured to perform frequency translation of the reflected signal.
16. 16. The apparatus of claim 1, wherein the side targets are selected from the group consisting of raised pavement markers, raised pavement markers with dihedral reflectors, snow shovelable pavement markers with dihedral reflectors, grooves in a path, road posts, post boxes, shoulders, concrete barriers, guardrails, and path edges.
17. 17. The apparatus of claim 1, wherein the inertial measurement unit comprises an accelerometer that provides lateral acceleration, and wherein the lateral acceleration is integrated twice to provide a change in lateral position of the vehicle between targets.
18. 18. The apparatus of claim 1, wherein the inertial measurement unit comprises a gyroscope that provides a yaw rate, and wherein the yaw rate is integrated once to provide a change in heading of the vehicle, and wherein the change in heading is used to determine a change in lateral position of the vehicle between the targets.
19. 19. The apparatus of claim 1, wherein the inertial measurement unit comprises a magnetometer that provides a direction of the vehicle, and wherein the direction is used to determine a change in lateral position of the vehicle between targets.
20. 20. The apparatus of claim 1, wherein the lateral distance from the radar sensor and the change in lateral position from the inertial measurement unit are combined via complementary filters.

Description

Vehicle guidance using IMU and radar with reflective targets located on or near a driving surface RELATED APPLICATIONS The present application claims priority from U.S. provisional patent application (1) application Ser. No. 63/543,444, filed 10/2023, entitled "Radar-Based and IMU-Based Vehicle Guidance using Radar Reflectors Embedded in Pavement Markers on a Driving Surface";(2) application Ser. No. 63/605,500, filed 12/2023, entitled ""Radar-Based and IMU-Based Vehicle Guidance using Radar Reflectors Embedded in Pavement Markers on a Driving Surface";, and (3) application Ser. No. 63/683,882, filed 16/2024, entitled "Radar-Based Vehicle Guidance Using Reflectivity of Targets on or NEAR THE DRIVING Surface". The entire disclosure of each of the above-identified priority patent applications is incorporated herein by reference. The subject matter of the present application is also related to the patent applications filed by the applicant (1) International patent application No. PCT/US2023/028710 entitled "7 th month 26 of "Radar-Based Vehicle Guidance Using Radar Reflectors Embedded in Pavement Markers on a Driving Surface",2023, claiming priority to each of (a) U.S. provisional patent applications No.63/474,257 entitled" Vehicle Guidance System "filed by 2022, 8 th month 1; (b) No.63/474,383 filed 8/10 in 2022, titled" Vehicle Guidance System "; (c) No.63/576,322, titled" Short-RANGE RADAR for use IN VEHICLE LATERAL Guidance and Control ", no.63/576,323, titled" Vehicle Guidance System ", no.63/454,669, titled" "Radar-Based Vehicle Guidance System Using Dihedral Corner Reflector Embedded in Pavement Marker";(f)2023 "No. 63/464,532, titled" Vehicle Guidance System ", no.63/464,527, titled" Short range radar for vehicle lateral navigation and control ", no. 2023/5" 5 (g) No.63/464,527, titled "Short range radar for vehicle lateral navigation and control", no. h) No.63/466,612, titled "Vehicle Guidance System", no.63/469,920, titled ""Radar-Based Vehicle Guidance Using Corner Reflectors Embedded in Pavement Markers on a Driving Surface";", and (2) International patent application No. 3484/US 2024/027899, titled "2023/5" and U.S. 2025/4/470, which are titled "2023/5 for vehicle lateral navigation and control", and (h) No.63/466, and (i) No.63/469,920, titled "2023/31, and ("Radar-Based Vehicle Guidance Using Arrays of Reflectors Embedded in or Under a Road Line on a Driving Surface",) U.S. 2024/027899, which are entitled" Short range radar for vehicle lateral navigation and control ", and which are entitled" temporary priority application No. 63/76, which are issued "3/5". The entire disclosures of all of the above patent applications are hereby incorporated by reference. Technical Field The field of the present disclosure relates generally to control of automobiles or similar land vehicles. More particularly, the present disclosure relates to controlling a vehicle or assisting in controlling the lateral positioning of a vehicle, particularly a vehicle, using radar (radio detection and ranging) reflectivity of an object located on or near a road or other driving surface. Background Radar has been used with automobiles for a variety of purposes, such as blind spot detection and forward collision warning. However, radar is conventionally not used to perform or assist in performing lateral steering of an automobile. In practice, electronic lateral steering or steering assist systems typically collect and process visual data. This method is complex and limited or not available in severe weather (e.g., rain, snow, ice, fog), smoke and darkness. Road routes and pavement markers are typically deployed on or near a driving surface to demarcate road or lane boundaries. Shoulders, concrete obstacles, and other roadside objects sometimes also distinguish edges of roads or lanes. Disclosure of Invention The present disclosure relates generally to the use of radar sensors or transceivers and Inertial Measurement Units (IMUs) on or in land vehicles to perform or assist in performing lateral steering, such as lane-based ADAS functions. At least one radar sensor is mounted on the vehicle and oriented to transmit radar signals downwardly and laterally from the side of the vehicle and to receive return reflected signals from side targets on or near the side of the road or roadway. These side targets may be, for example, conventional pavement markers, modified pavement markers with enhanced radar reflectivity, road shoulders, concrete obstacles, marker posts, and the like. The round-trip time of flight of the radar signal to and from the targets as the vehicle passes over each target may provide accurate lateral distance measurements and thus lateral vehicle position information for steering, steering assistance, or lateral position checking. Between intermittently spaced side targets, various types of information from the IMU may be used to determine lateral position information for the vehicle. In this way, the combination of r