BR-102025010703-A2 - RADAR CALIBRATION SYSTEM, METHOD FOR CALIBRATING A RADAR SYSTEM, AND NON-TRANSIENT COMPUTER-READABLE MEDIUM

Abstract

The present invention generally relates to non-transient, computer-readable methods, systems, apparatus, and means for calibrating a radar system, specifically for configuring the radar system according to the details of the radar system's mounting on a host system. By enabling the automatic calibration of a radar system to account for its mounting position on the host system, the systems of the present invention can make radar systems more accurate in an efficient and economical manner. More precisely, the systems of the present invention can employ a constellation of reflective radar markers, called calibration markers, distributed throughout a volume of space within view of a radar system mounted on a host system. The radar system can use its antenna array to determine the coordinates of the calibration markers. These coordinates can then be compared to predetermined expected coordinates for the calibration markers to determine the deviation between the intended mounting and the actual mounting of the antenna array.

Inventors

• Scott Bergen

Assignees

• DEERE & COMPANY

Dates

Publication Date

20260310

Application Date

20250527

Priority Date

20240628

Claims (15)

1. 1. Radar calibration system, characterized in that it comprises: a constellation of calibration markers, wherein: each constellation of calibration markers is positioned at an associated calibration marker position that has known coordinates relative to a coordinate system of the radar calibration system; a radar system configured to detect and determine the position of one or more nearby objects, wherein: the radar system comprises an antenna array comprising one or more transmitting antennas configured to transmit radar signals and one or more receiving antennas configured to receive echoes of the transmitted radar signals; and the antenna array is mounted on a host system at an actual mounting position and an actual mounting orientation, wherein the actual mounting position deviates from a designated mounting position and the actual mounting orientation deviates from a designated mounting orientation; the radar system further comprises a radar system controller configured to determine mounting correction information: storing, for each constellation of calibration markers, expected calibration marker coordinates determined by the radar; Determining, for each constellation of calibration markers, the actual coordinates of the calibration marker determined by the radar using the antenna array; determining mounting position deviation information for the antenna array using the expected coordinates of the calibration marker determined by the radar and the actual coordinates of the calibration marker determined by the radar; and configuring mounting calibration parameters using the determined position deviation information.
2. 2. System according to claim 1, characterized in that the radar system is additionally configured to: determine coordinates for one or more objects using the antenna array; and modify the coordinates determined for the one or more objects based on the configured mounting calibration parameters.
3. 3. System according to claim 1, characterized in that: the host system comprises an automotive vehicle; and the constellation of calibration markers is a component of a production line.
4. 4. System according to claim 1, characterized in that the radar system controller is additionally configured to determine mounting correction information in response to the detection of a calibration mode marker.
5. 5. Radar calibration system according to claim 1, characterized in that: the host system is positioned at a real host system position, wherein the real host system position deviates from a designated host system position with known coordinates relative to the radar calibration system coordinate system; the radar calibration system further comprises a plurality of location sensors configured to determine the real host system position; and the radar system controller is further configured to: store information indicating the designated host system position; obtain information indicating the real host system position determined by the plurality of location sensors; determine host system position deviation information using the stored designated host system position information and the obtained real host system position information; and adjust the expected and stored calibration marker coordinates, determined by the radar, based on the determined host system position deviation information.
6. 6. System according to claim 5, characterized in that the plurality of location sensors comprises a plurality of location lasers.
7. 7. A method for calibrating a radar system, characterized in that it comprises: storing, for each constellation of calibration markers, expected calibration marker coordinates determined by radar, wherein each constellation of calibration markers is positioned at an associated calibration marker position that has known coordinates relative to a coordinate system of the radar calibration system; determining, for each constellation of calibration markers, actual calibration marker coordinates determined by radar using an antenna array of the radar system, wherein: the antenna array is mounted on a host system at an actual mounting position and an actual mounting orientation; and the actual mounting position deviates from a designated mounting position and the actual mounting orientation deviates from a designated mounting orientation; determining mounting position deviation information for the antenna array using the expected calibration marker coordinates determined by radar and the actual calibration marker coordinates determined by radar; and setting array calibration parameters using the determined position deviation information.
8. 8. Method according to claim 7, characterized in that it further comprises: determining coordinates for one or more objects using the antenna array; and modifying the coordinates determined for the one or more objects based on the configured mounting calibration parameters.
9. 9. Method according to claim 7, characterized in that: the host system comprises an automotive vehicle; and the constellation of calibration markers is a component of a production line.
10. 10. Method according to claim 7, characterized in that it comprises determining assembly correction information using deviation information from the determined assembly position.
11. 11. Method according to claim 7, characterized in that the determination of the actual coordinates of the calibration marker determined by radar is in response to the detection of a calibration mode marker.
12. 12. A method according to claim 7, characterized in that it further comprises: storing information indicating a designated position of the host system, wherein the host system is positioned at an actual position of the host system, wherein the actual position of the host system deviates from the designated position of the host system; obtaining information indicating the actual position of the host system using a plurality of localization sensors; determining host system position deviation information using the stored designated host system position information and the obtained actual host system position information; and adjusting the expected and stored calibration marker coordinates, determined by radar, based on the determined host system position deviation information.
13. 13. Method according to claim 12, characterized in that the plurality of location sensors comprises a plurality of location lasers.
14. 14. Non-transient computer-readable medium, characterized in that it comprises instructions which, when executed by one or more processors, cause the one or more processors to direct the implementation of a method for calibrating a radar system as defined in any one of claims 7 to 13.
15. 15. A method for calibrating a radar system, characterized in that it comprises: obtaining, for each constellation of calibration markers, expected coordinates of calibration markers determined by radar, wherein each constellation of calibration markers is positioned at an associated calibration marker position that has known coordinates relative to a coordinate system of the radar calibration system; obtaining, for each constellation of calibration markers, actual coordinates of the calibration marker determined by radar using an antenna array of the radar system, wherein: the actual coordinates of the calibration marker determined by radar are determined using an antenna array of the radar system; the antenna array is mounted on a host system at an actual mounting position and an actual mounting orientation; and the actual mounting position deviates from a designated mounting position and the actual mounting orientation deviates from a designated mounting orientation; determining mounting position deviation information for the antenna array using the expected coordinates of the calibration marker determined by radar and the actual coordinates of the calibration marker determined by radar; and configuring mounting calibration parameters using the determined position deviation information.

Description

FUNDAMENTALS Technical Field [001] The present invention generally relates to radar systems and, more specifically, to non-transient computer-readable methods, systems, apparatus and means for calibrating radar systems. Description of the Fundamentals [002] Radar imaging systems are specialized radar systems configured to detect the relative position of objects in a local environment. Radar imaging systems can be used for a variety of purposes, but they can be used in particular to assist a host system, such as a robot or an autonomous car, in navigating an environment. When used as a sensor for a host system, an important consideration is the position and orientation of the radar imaging system relative to the host system. Like many sensors, a radar imaging system only determines the position of objects relative to itself. To utilize this positioning information for the host system, this positioning information must be translated from the perspective of the radar imaging system and related to the rest of the host system. This involves knowing the relative position and orientation of the radar imaging system relative to the rest of the host system. [003] To the extent that the “known” relative position and orientation of the radar imaging system are far from its true position and orientation, the accuracy of the information derived from the radar imaging system is proportionally degraded. Therefore, it is important that the “known” position and orientation of a radar imaging system be adequately accurate. The required level of accuracy is generally such that the error induced by incorrect position and orientation information is negligible compared to the inaccuracy of the radar imaging system itself. Advances in the accuracy of modern radar imaging systems have made it necessary for position information to be known with an accuracy of a few millimeters. [004] Therefore, systems for calibrating a radar system efficiently and autonomously are highly desirable. BRIEF DESCRIPTION OF THE DRAWINGS [005] The embodiments and various aspects of the present invention are illustrated in the following detailed description and in the accompanying figures. Several properties shown in the figures are not drawn to scale. [006] Figure 1 is a block diagram of a radar system. [007] Figure 2 is a block diagram of a multiple-input multiple-output (MIMO) radar system. [008] Figure 3 is a block diagram of a MIMO radar array, like the MIMO radar array in Figure 2. [009] Figure 4 is a block diagram of a transmitter element of a MIMO radar system, such as the MIMO radar system in Figure 2. [0010] Figure 5 is a block diagram of a receiver element of a MIMO radar system, such as the MIMO radar system in Figure 2. [0011] Figure 6 is a block diagram of a radar calibration system according to an exemplary embodiment of the present invention. [0012] Figure 7 is a block diagram of a host system, like the host system in Figure 6. [0013] Figure 8 is a flowchart of an exemplary method for calibrating radar systems, such as the radar system in Figure 7. [0014] Figure 9 is a flowchart of an exemplary method for adjusting the expected coordinates of the calibration marker. [0015] Figure 10 is a block diagram of a production line incorporating a radar calibration system, like the radar calibration system in Figure 6. [0016] Figure 11 is a block diagram of a production line station incorporating a radar calibration system, like the radar calibration system station in Figure 10. DETAILED DESCRIPTION [0017] Detailed references will now be made to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings, in which the same numbers in different drawings represent identical or similar elements, unless otherwise represented. The implementations presented in the following description of exemplary embodiments do not represent all implementations consistent with the invention. Instead, they are merely examples of apparatus and methods consistent with aspects related to the invention, as stated in the appended claims. Specific aspects of the present invention are described in more detail below. The terms and definitions provided in this document prevail if they conflict with terms and/or definitions incorporated by reference. [0018] The present invention generally relates to systems and methods for calibrating a radar system, specifically for configuring the radar system according to details of the radar system's mounting on a host system. These radar calibration systems can be useful in a wide range of applications that utilize radar systems for environmental imaging. By enabling the automatic calibration of a radar system to account for deviations in its actual mounting from its designated mounting position on a host system, the systems of the present invention can make radar systems more accurate in an efficient and economical manner. By the same process, embodimen