Method for lidar pitch angle compensation in a motor vehicle, computer program product, computer-readable storage medium and motor vehicle

Abstract

The invention relates to a computer-implemented method for tilt angle compensation of a lidar (12) in a motor vehicle (10) comprising the steps of: scanning (S1) an area in front of the motor vehicle (10) with the lidar (12), wherein a focus (14) of the lidar (12) is directed at the horizon of a road; predicting (S2) a vehicle movement in the vertical direction using a predetermined road surface map, wherein a tilt angle of the motor vehicle (10) for the predicted movement is determined; calculating (S3) a tilt angle correction to reset the lidar focus (14) to the horizon using the determined tilt angle; and adjusting (S4) the focus of the lidar (12) using the calculated tilt angle correction. The present invention further relates to a motor vehicle (10) configured to carry out the method, a computer program product, and a non-volatile, computer-readable medium.

Description

AREA OF INVENTION

[0001] The present invention relates to the field of motor vehicles. In particular, the present invention relates to a computer-implemented method for lidar pitch angle compensation in a motor vehicle. Furthermore, the present invention relates to a corresponding computer program product, a computer-readable storage medium, and a motor vehicle. BACKGROUND INFORMATION

[0002] Lidar (Light Detection and Ranging) systems play a central role in modern motor vehicles, particularly in advanced driver assistance systems. These systems utilize lidar technology to precisely scan the vehicle's surroundings, enabling crucial functions such as obstacle detection and collision avoidance. Optimizing the lidar's alignment is essential, with the focus typically directed towards the horizon, as distant objects are often located in this area. However, shifts in the vehicle's orientation relative to the road can disrupt the lidar's initial alignment, diverting its focus from the horizon. Such deviations compromise the system's effectiveness and necessitate robust solutions to ensure optimal lidar performance under varying road conditions. SUMMARY OF THE INVENTION

[0003] The object of the present invention is to provide a method, a computer program product, a computer-readable storage medium and a motor vehicle with which a pitch angle of a lidar is compensated.

[0004] This problem is solved by a method, a computer program product, a computer-readable storage medium, and a motor vehicle according to the independent claims. Advantageous embodiments are described in the dependent claims.

[0005] One aspect of the present invention relates to a computer-implemented method for lidar pitch angle compensation in a motor vehicle, comprising the following steps: scanning an area in front of the motor vehicle by the lidar, wherein a focus of a lidar is directed towards a horizon of a road, predicting a vehicle movement in a vertical direction using a predetermined road surface map, wherein a pitch angle of a motor vehicle is determined for the predicted movement, calculating a pitch angle correction to reset the lidar focus to the horizon using the determined pitch angle, and adjusting the focus of a lidar using the calculated pitch angle correction.

[0006] During vehicle operation, the lidar may be focused on the horizon, but the lidar focus can shift away from the horizon due to changes in the road surface, such as a change in road gradient. To account for this and reset the focus to the horizon, a tilt angle correction can be calculated to compensate for the road's gradient. Specifically, the tilt angle correction can be used to generate a new scan command for the lidar head to adjust the scan position for the next image.

[0007] To determine the inclination angle of a road and thus of a vehicle, a road surface map is provided. This map can either be measured by the vehicle itself or predefined and provided to the vehicle from an external data source. The road surface map can include information about the road topology, particularly the vertical curvature of the road. For example, the road surface map can be provided as a high-resolution map containing highly accurate gradient values. Using the road surface map and the vehicle's position, an impending change in the vehicle's inclination angle can be determined. Specifically, the vehicle's inclination angle can be predicted for each subsequent position on the road. In this way, the vehicle's movement can be forecast.

[0008] Consequently, a difference between the respective tilt angle and the horizon can be determined in order to calculate the tilt angle correction for each position.

[0009] The process can be carried out by an electronic control unit of the motor vehicle, specifically comprising the steps of predicting the vehicle's movement, calculating the tilt angle correction, and generating a control signal to adjust the focus of a lidar. In particular, the focus of a lidar can be an area of ​​interest encompassing a greater number of scan lines than positions outside the focus. To adjust the focus of the lidar, the lidar can include an adjustment device that can be controlled to adjust the position.

[0010] The advantage of the present invention is that robustness and accuracy of pitch compensation can be achieved.

[0011] According to one embodiment, the focus of a lidar is an area of ​​interest that encompasses a denser lidar scan.

[0012] In another embodiment, a lidar reflection of a road in front of the motor vehicle is additionally used to calculate a road angle and / or to fit a plane as a road reference for calculating the tilt angle correction.

[0013] In another embodiment, the map of the road surface is an externally provided high-resolution map of the road.

[0014] In another embodiment, the motor vehicle determines the road map using at least one camera of the motor vehicle.

[0015] According to another embodiment, the road surface map is used as the basis truth to evaluate the performance of a correction by comparing the calculated slope angle correction with an actual road topology from the road surface map.

[0016] Another aspect of the present invention relates to a computer system for lidar pitch compensation in a motor vehicle, comprising a control circuit configured to: scan an area in front of the motor vehicle with the lidar, the lidar focus being directed at the horizon of a road; predict vehicle movement in a vertical direction using a predetermined road surface map, determining a pitch angle of the motor vehicle for the predicted movement; calculate a pitch correction to reset the lidar focus to the horizon using the determined pitch angle; and adjust the lidar focus using the calculated pitch correction. This aspect of the invention offers the same advantages and variations as the computer-implemented method.

[0017] Another aspect of the present invention relates to a computer program product that includes program code means for carrying out a method according to the preceding aspect. The computer program product can also be considered a computer program.

[0018] Another aspect of the present invention relates to one or more non-volatile, computer-readable media that store instructions executable by a control circuit to scan an area in front of a motor vehicle with the lidar, wherein the lidar's focus is directed towards the horizon of a road, to predict vehicle movement in a vertical direction using a predetermined road surface map, wherein a tilt angle of the motor vehicle is determined for the predicted movement, to calculate a tilt angle correction to reset the lidar's focus to the horizon using the determined tilt angle, and to adjust the lidar's focus using the calculated tilt angle correction.

[0019] Another aspect of the present invention relates to a non-volatile, computer-readable medium that contains at least the computer instructions according to the preceding aspect.

[0020] Furthermore, the present invention relates to a motor vehicle with at least one lidar, wherein the motor vehicle is configured to carry out a method according to the preceding aspect.

[0021] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as those mentioned in the following description of the figures and / or illustrated in the figures alone, can be used not only in the combinations specified, but also in any other combination or on their own, without departing from the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The new features and properties of the disclosure are set forth in the accompanying claims. The accompanying drawings, which form part of this disclosure, illustrate exemplary embodiments and, together with the description, serve to explain the disclosed principles. The same numbers are used in the figures to indicate identical features and components. Some embodiments of systems and / or methods according to embodiments of the present subject matter are described below only by way of example and with reference to the accompanying figures.

[0023] The drawings show in: Fig. 1 a schematic side view of a motor vehicle; Fig. 2 a schematic flowchart according to one embodiment of a method. Fig. 3. Schematic calculation system for lidar pitch angle compensation.

[0024] In the figures, identical elements or elements with the same function are indicated by the same reference symbols. DETAILED DESCRIPTION

[0025] In this document, the word "exemplary" is used to mean "serving as an example, instance, or illustration." Each embodiment or implementation of the subject matter described herein as "exemplary" is not necessarily to be understood as preferred or advantageous over other embodiments.

[0026] While the disclosure is open to various modifications and alternative forms, specific embodiments are illustrated by way of example in the drawing and are described in detail below. It should be understood, however, that the disclosure is not intended to be limited to the specific forms disclosed, but rather, on the contrary, to cover all modifications, equivalents, and alternatives that fall within the scope of the disclosure.

[0027] The terms "includes," "contains," or other variations thereof are intended to cover non-exclusive inclusion, so that a system, device, or process that includes a list of components or steps may contain not only those components or steps but may also contain other components or steps not expressly listed or belonging to such system, device, or process. In other words, one or more elements in a system or device preceded by the term "includes" or "includes" do not, without further limitations, preclude the presence of other elements or additional elements in the system or process.

[0028] The following detailed description of the embodiment of the disclosure refers to the accompanying drawing, which forms part of the disclosure and illustrates a specific embodiment in which the disclosure can be implemented. This embodiment is described in sufficient detail to enable the person skilled in the art to apply the disclosure, and it is understood that other embodiments may be used and modifications may be made without departing from the scope of the present disclosure. The following description is therefore not to be understood in a restrictive sense.

[0029] Fig. Figure 1 shows a schematic side view of a motor vehicle 10 according to an exemplary embodiment. The motor vehicle 10 comprises at least one Light Detection and Ranging (Lidar) unit 12 configured to scan the environment of the motor vehicle 10, in particular its direction of travel. Furthermore, the Lidar 12 can be focused on specific areas, the focus being an area of ​​interest that is scanned at a higher density than areas outside the focus. In this figure, two different focus directions are shown, for example, by reference numerals 14 and 16. In particular, it is preferred that the focus of a Lidar 12 is directed towards a horizon, since distant objects are located in this area.

[0030] In the Fig. In the example situation shown in Figure 1, the lidar focus 14 is not aligned with the horizon due to a slope α of the road. To realign the lidar focus 14 with the horizon, for example, in the direction of focus 16, the vehicle 10 can be configured to perform slope angle compensation for the lidar 12. For this purpose, the vehicle 10 can have an electronic control unit 18 that includes a predefined road surface map. The road map can be a high-resolution map of the road, either provided externally or measured directly by the vehicle 10, for example, by at least one camera (not shown) of the vehicle 10. The road surface map can include the topology of the road, in particular the slope α.

[0031] Using this road map, a current inclination angle α of the road, and thus of the vehicle 10, can be determined for each position on the road. Furthermore, an inclination angle correction can be calculated to reset the focus 14 to the focus 16 in the direction of the horizon, depending on the determined inclination angle α. In particular, the electronic control unit 18 can generate a control signal containing the inclination angle correction to control the lidar 12 to adjust the focus 14 to the focus 16.

[0032] In addition to the road surface map, a lidar reflection of the road in front of the vehicle 10 can be used to calculate a road angle and / or to fit a plane as a road reference for calculating the inclination angle correction. For example, a lidar reflection 5 to 30 meters in front of the vehicle 10 can be used in addition to correcting its lidar 12.

[0033] Fig. Figure 2 shows a schematic flowchart according to an embodiment of a method for lidar pitch angle compensation in a motor vehicle 10. In step S1, an area in front of the motor vehicle 10 is scanned with the lidar 12, wherein a focus of a lidar 12 is directed towards a horizon.

[0034] In step S2, the vehicle movement in the vertical direction is predicted using a predetermined road surface map, whereby an inclination angle α of the motor vehicle 10 is determined for the predicted movement.

[0035] In step S3, the motor vehicle 10, in particular an electronic control unit 18 of the motor vehicle 10, calculates an inclination angle correction in order to reset the lidar focus to the horizon based on the determined inclination angle.

[0036] Finally, in step S4, the lidar 12 adjusts the focus to the horizon based on the calculated tilt angle correction. For example, the lidar can adjust the focus towards the horizon by using at least one laser that emits light onto an azimuth mirror and an elevation mirror. The rate of change of the elevation mirror can be slowed down around the area of ​​interest. As those skilled in the art know, this method is not the only method for focusing on the horizon using tilt angle correction, and the scope of the invention is not intended to be limited to this example.

[0037] Furthermore, the data from this method can be used in a development process where ground truth data is required to evaluate the performance of this algorithm. For example, the calculated inclination angle correction can be compared with the actual road topology from the road map. The road map can serve as ground truth data, decoupled from other measurements of the vehicle, such as lidar reflections, which can also be used as ground truth data.

[0038] Fig.Figure 3 shows a schematic computing system 20 for lidar pitch angle compensation in a motor vehicle 10. The computing system 20 can include a control circuit 22 configured to scan an area in front of the motor vehicle with the lidar 12, wherein a focus 14 of the lidar 12 is directed towards a horizon of a road, to predict vehicle movement in a vertical direction using a predetermined road surface map, wherein a pitch angle of the motor vehicle 10 is determined for the predicted movement, to calculate a pitch angle correction in order to reset the lidar focus 14 to the horizon using the determined pitch angle, and to adjust the focus of the lidar 12 using the calculated pitch angle correction. Reference sign 10 motor vehicle 12 Lidar 14 Lidar focus 16 Lidar focus 18 electronic control unit 20 computer system 22 Control circuit S1-S4 process steps

Claims

[1] Computer-implemented method for compensating the tilt angle of a lidar (12) in a motor vehicle (10), comprising the following steps: - Scanning (S1) an area in front of the motor vehicle (10) with the lidar (12), wherein a focus (14) of the lidar (12) is directed towards a road horizon; - Prediction (S2) of a vehicle movement in a vertical direction using a given road surface map, wherein an inclination angle of the motor vehicle (10) is determined for the predicted movement; - Calculate (S3) a tilt angle correction to reset the lidar focus (14) to the horizon using the determined tilt angle; - Adjusting (S4) the focus of the lidar (12) using the calculated tilt angle correction. [2] Computer-implemented method according to claim 1, wherein the focus (14, 16) of the lidar (12) is an area of ​​interest that includes a denser lidar scan. [3] Computer-implemented method according to claim 1 or 2, wherein, in addition to calculating the pitch angle correction, a lidar reflection (12) of the road in front of the motor vehicle (10) is used to calculate a road angle and / or to adapt a plane as a road reference. [4] Computer-implemented method according to any one of claims 1 to 3, wherein the map of the road surface is an externally provided high-resolution map of the road. [5] Computer-implemented method according to one of the preceding claims, wherein the motor vehicle (10) determines the road map by means of at least one camera of the motor vehicle (10). [6] Computer-implemented method according to any of the preceding claims, wherein the road surface map is further used as the basic truth data to evaluate the performance of the correction by comparing the calculated slope angle correction with an actual road topology from the road surface map. [7] Motor vehicle (10) with at least one lidar (12), wherein the motor vehicle (10) is configured to carry out a method according to any one of claims 1 to 6. [8] Computing system (20) for tilt angle compensation of a lidar (12) in a motor vehicle (10), comprising the following: a control circuit (22) configured for this purpose: to scan an area in front of the motor vehicle (10) using the lidar (12) (S1), wherein a focus (14) of the lidar (12) is directed towards a horizon of a road; to predict a vehicle movement in a vertical direction using a predetermined road surface map (S2), wherein an inclination angle of the motor vehicle (10) is determined for the predicted movement; to calculate a tilt angle correction (S3) in order to reset the lidar focus (14) to the horizon using the determined tilt angle; to adjust the focus of the lidar (12) using the calculated tilt angle correction (S4). [9] Computing system (20) according to claim 8, wherein the focus (14, 16) of the lidar (12) is an area of ​​interest which includes a denser lidar scan. [10] Computing system (20) according to claim 8 or 9, wherein, in addition to calculating the pitch angle correction, a lidar reflection (12) of the road in front of the motor vehicle (10) is used to calculate a road angle and / or to fit a plane as a road reference. [11] Computing system (20) according to one of claims 8 to 10, wherein the map of the road surface is an externally provided high-resolution map of the road. [12] Computing system (20) according to any one of the preceding claims 8 to 11, wherein the motor vehicle (10) determines the road map by means of at least one camera of the motor vehicle (10). [13] Computing system (20) according to any one of the preceding claims 8 to 12, wherein the road surface map is further used as the basic truth data to evaluate the performance of the correction by comparing the calculated slope angle correction with an actual road topology from the road surface map. [14] One or more non-volatile, computer-readable media storing instructions that can be executed by a control circuit (22) to: to scan an area in front of the motor vehicle (10) using the lidar (12) (S1), wherein a focus (14) of the lidar (12) is directed towards a horizon of a road; to predict a vehicle movement in a vertical direction using a predetermined road surface map (S2), wherein an inclination angle of the motor vehicle (10) is determined for the predicted movement; to calculate a tilt angle correction (S3) in order to reset the lidar focus (14) to the horizon using the determined tilt angle; to adjust the focus of the lidar (12) using the calculated tilt angle correction (S4). [15] Non-volatile computer-readable medium containing at least the computer instructions according to claim 14.

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