Driving control system

Abstract

To provide a travel control device capable of accurately estimating shape of a target course.SOLUTION: A travel control device 1 comprises a processor. The processor generates a target route to a destination; estimates a self position of the vehicle; calculates a target reaching point on the target route; generates a target point candidate including a target point within predetermined distance and angle from the self position of the vehicle, based on a front-viewing angle of the vehicle and a front-gazing distance from the self position of the vehicle to the target reaching point; and calculates a point at the time as a target point, when the target point becomes outside the front-viewing angle of the vehicle while searching the target point candidate.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a driving control device.

Background Art

[0002] Patent Document 1 describes a technique for treating a steering operation by a driver as a feedback control operation for a predicted vehicle position and vehicle behavior at a forward gaze point, and reproducing a driving situation in which the vehicle behavior changes using a vehicle model. In this technique, when the vehicle exists on a target course set in a driver model, a point at a predetermined forward gaze distance from the vehicle is set as the forward gaze point. Subsequently, in this technique, when advancing to the forward gaze point while maintaining the current vehicle posture, the deviation between the lateral displacement of the vehicle that occurs and the target course, and the deviation between the yaw angle displacement and the target yaw angle are detected. Then, in this technique, the steering angle to be applied to the vehicle model is calculated by feedback control using the amount of position deviation and the position deviation gain, and the amount of yaw angle deviation and the yaw angle deviation gain.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, when the path coordinate point sequence of a preset target course is not set smoothly, for example, in the case of a curve, it is difficult to accurately estimate the shape of the target course, and there is room for improvement.

[0005] The present disclosure has been made in view of the above, and an object thereof is to provide a driving control device capable of accurately estimating the shape of a target course.

Means for Solving the Problems

[0006] To solve the above-mentioned problems and achieve the objective, the driving control device according to this disclosure is a driving control device that includes a processor and controls the driving of a vehicle, wherein the processor generates a target path to a destination, estimates the vehicle's own position, calculates a target destination on the target path, generates candidate target points including the target point within a predetermined distance and angle from the vehicle's own position based on the field of view angle in front of the vehicle and the forward gaze distance from the vehicle's own position to the target destination, and calculates the point at that time as the target point if the target point goes outside the vehicle's forward field of view during the search for candidate target points. [Effects of the Invention]

[0007] According to this disclosure, the shape of the target course can be estimated with high accuracy. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a diagram showing a schematic configuration of a driving control device according to one embodiment. [Figure 2] Figure 2 is a flowchart showing an overview of the processes performed by a driving control device according to one embodiment. [Figure 3] Figure 3 schematically shows the position of a target point when a vehicle is traveling along a route with good visibility. [Figure 4] Figure 4 is a plan view showing the position of the target point under the conditions shown in Figure 3. [Figure 5] Figure 5 schematically shows the position of a target point when a vehicle is traveling along a route with poor visibility. [Figure 6] Figure 6 is a plan view showing the position of the target point under the conditions shown in Figure 5. [Modes for carrying out the invention]

[0009] The following description will explain the driving control device according to the embodiments of this disclosure with reference to the drawings. However, this disclosure is not limited to the following embodiments. In the following description, the same parts will be denoted by the same reference numerals.

[0010] [Overview of the driving control system] Figure 1 is a diagram showing a schematic configuration of a driving control device according to one embodiment. The driving control device 1 shown in Figure 1 is mounted on a vehicle. This vehicle is assumed to be an HEV (Hybrid Electric Vehicle), PHEV (Plug-in Hybrid Electric Vehicle), BEV (Battery Electric Vehicle), and FCEV (Fuel Cell Electric Vehicle), etc.

[0011] The driving control device 1 is implemented using a processor with hardware. This hardware includes, for example, memory, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field-Programmable Gate Array), and a GPU (Graphics Processing Unit). Below, we will describe an example in which the driving control device 1 uses a simple tracking algorithm (hereinafter simply referred to as "PutePersuite") for path following when an autonomous mobile vehicle travels along a set target path to a destination. This PutePersuite controls the vehicle's path following ability by using the forward gaze distance as one of the control parameters.

[0012] The driving control device 1 controls each component of the vehicle. The driving control device 1 loads a program stored on a storage medium into the working area of ​​the memory and executes it, and by controlling each component through the execution of the program, it realizes a function that matches a predetermined purpose. Specifically, the driving control device 1 includes a path generation unit 10, a self-position estimation unit 11, a nearest neighbor calculation unit 12, a target destination calculation unit 13, a target angular velocity calculation unit 14, a translational velocity calculation unit 15, and a drive control unit 16.

[0013] The route generation unit 10 generates a target route to the destination and outputs this target route to the nearest neighbor calculation unit 12. Specifically, the route generation unit 10 generates a target route to the destination in accordance with user operation instructions from an external device such as a touch panel or mobile terminal, or instructions from an external server. Of course, the route generation unit 10 may also automatically generate a target route to the destination. In this case, the route generation unit 10 generates a target route to the destination based on image data generated by an imaging device installed on the vehicle, the vehicle's own position from the self-position estimation unit 11 (described later), and the vehicle's current orientation.

[0014] The self-position estimation unit 11 estimates the vehicle's own position and outputs this estimation result to the nearest neighbor calculation unit 12. Here, the self-position refers to the position information of a reference coordinate system used to represent the vehicle's current bearing, current longitude, and latitude. Specifically, the self-position estimation unit 11 is configured using a GPS (Global Positioning System) sensor, which is an example of a Navigation Satellite System (NSS), or a LiDAR (Light Detection and Ranging) capable of generating distance measurement data.

[0015] The nearest neighbor calculation unit 12 calculates the nearest neighbor point from the user's own position on the target path based on image data captured by an imaging device installed on the vehicle, the target path input from the path generation unit 10, and the user's own position input from the self-position estimation unit 11, and outputs this calculated nearest neighbor point to the target destination calculation unit 13. Specifically, the nearest neighbor calculation unit 12 calculates the nearest neighbor point from the user's own position on the target path based on two or more image data with different acquisition times, the target path, the user's own position, and a pre-trained model or rule learned by machine learning. As a method for searching for nearest neighbor points, nearest neighbor search, such as linear search, which searches for the nearest neighbor point of the closest point in metric space, is used. Furthermore, the method for constructing the pre-trained model used in the nearest neighbor calculation unit 12 is not particularly limited, and various machine learning methods such as deep learning using neural networks, support vector machines, decision trees, Naive Bayes, and k-nearest neighbors can be used.

[0016] The target arrival point calculation unit 13 calculates target point candidates within a predetermined distance or within a predetermined angle from the vehicle's self-position based on the forward viewing angle in front of the vehicle acquired from various sensors provided on the vehicle, the forward viewing distance from the vehicle's self-position to the target arrival point in front of the vehicle acquired from various sensors provided on the vehicle, and the nearest point calculated by the nearest point calculation unit 12. Specifically, the target arrival point calculation unit 13 searches for a target point whose distance from the vehicle's self-position is the forward viewing distance (Look Ahead Distance). Then, during the search for the target point, the target arrival point calculation unit 13 determines whether the target point is outside the forward viewing angle. If the target point is not outside the forward viewing angle, it increases the forward viewing distance to be greater than the predetermined distance and calculates (sets) the target point. On the other hand, when the target point is outside the forward viewing angle, the target arrival point calculation unit 13 decreases the forward viewing distance to be less than the predetermined distance and calculates (sets) the point at that moment when the target point is outside the forward viewing angle as the target point. Also, the target arrival point calculation unit 13 sequentially calculates target point candidates at every predetermined distance from the vehicle's self-position based on the forward viewing angle in front of the vehicle acquired from various sensors provided on the vehicle, the forward viewing distance from the vehicle's self-position to the target arrival point in front of the vehicle acquired from various sensors provided on the vehicle, and the nearest point calculated by the nearest point calculation unit 12.

[0017] The target angular velocity calculation unit 14 calculates a target angular velocity for controlling the direction of the vehicle based on the target arrival point calculated by the target arrival point calculation unit 13, and outputs the calculated target angular velocity to the drive control unit 16.

[0018] <酬 The translational speed calculation unit 15 calculates the target translational speed of the vehicle and outputs the calculated target translational speed to the drive control unit 16.

[0019] The drive control unit 16 generates a control signal for controlling the speed of the vehicle based on the target angular velocity calculated by the target angular velocity calculation unit 14 and the target translational speed calculated by the translational speed calculation unit 15, and outputs this control signal to a steering mechanism of the vehicle (not shown).

[0020] 〔Processing of the Travel Control Device〕 Next, the processes executed by the travel control device 1 will be described. FIG. 2 is a flowchart showing an overview of the processes executed by the travel control device 1.

[0021] As shown in FIG. 2, first, the route generation unit 10 generates a target route to the destination (step S1). In this case, the route generation unit 10 outputs the generated target route to the destination to the nearest point calculation unit 12.

[0022] Subsequently, the self-position estimation unit 11 estimates the self-position of the vehicle itself (step S2). In this case, the self-position estimation unit 11 outputs the estimated self-position to the nearest point calculation unit 12.

[0023] After that, based on the image data captured by the imaging device provided on the vehicle, the target route input from the route generation unit 10, and the self-position input from the self-position estimation unit 11, the nearest point calculation unit 12 calculates the nearest point from the self-position on the target route (step S3). In this case, the nearest point calculation unit 12 outputs the calculated nearest point to the target arrival point calculation unit 13.

[0024] Subsequently, based on the forward viewing angle in front of the vehicle acquired from various sensors provided on the vehicle, the forward viewing distance from the self-position of the vehicle in front of the vehicle acquired from various sensors provided on the vehicle to the target arrival point, and the nearest point calculated by the nearest point calculation unit 12, the target arrival point calculation unit 13 searches for a point (target point) within a predetermined distance or within a predetermined angle from the self-position of the vehicle where the distance from the self-position of the vehicle is the forward viewing distance (step S4).

[0025] After that, during the search for the target point, the target arrival point calculation unit 13 determines whether the target point is outside the forward viewing angle (step S5). If the target point is outside the forward viewing angle during the search for the target point (step S5: Yes), the target arrival point calculation unit 13 proceeds to step S7. On the other hand, if the target point is not outside the forward viewing angle during the search for the target point (step S5: No), the target arrival point calculation unit 13 proceeds to step S6.

[0026] In step S6, the target point calculation unit 13 calculates the target point, which is the target point located within a predetermined distance or angle from the vehicle's own position, based on the forward field of view, forward gaze distance, and nearest neighbor point, by setting the forward gaze distance to be greater than a predetermined distance.

[0027] Figure 3 schematically shows the position of a target point when a vehicle is traveling along a route with good visibility. Figure 4 is a plan view showing the position of the target point under the conditions of Figure 3. In Figure 4, the horizontal axis represents the direction of travel (x-axis), and the vertical axis represents the direction perpendicular to the direction of travel (y-axis).

[0028] As shown in Figures 3 and 4, the target point calculation unit 13 searches for a target point, and the vehicle 100's target point is within the forward field of view, for example, when the vehicle 100 is traveling on a straight road. In this case, the target point calculation unit 13 calculates a target point that includes at least the target point P1 within a predetermined distance or angle from the vehicle 100's own position, by setting the forward field of view, forward gaze distance, and nearest neighbor point to be greater than a predetermined distance. As a result, the vehicle 100 can travel while following the target path while ensuring stability when traveling in a straight line.

[0029] Returning to Figure 2, we continue the explanation from step S7 onwards. In step S7, the target point calculation unit 13 calculates the target point, which is the target point located within a predetermined distance or angle from the vehicle's own position, by setting the forward gaze distance D1 to be smaller than a predetermined distance, based on the forward field of view, forward gaze distance, and nearest neighbor point.

[0030] Figure 5 schematically shows the position of a target point when a vehicle is traveling along a route with poor visibility. Figure 6 is a plan view showing the position of the target point under the conditions of Figure 5. In Figure 6, the horizontal axis represents the direction of travel (x-axis), and the vertical axis represents the direction perpendicular to the direction of travel (y-axis).

[0031] As shown in Figures 5 and 6, let's consider the case where the vehicle 100's target point is outside the forward field of view while the target point calculation unit 13 is searching for a target point, for example, when the vehicle 100 is traveling on a curved road. In this case, the target point calculation unit 13 calculates a target point that includes the target point P2 within a predetermined distance or angle from the vehicle 100's own position, based on the forward field of view, the forward gaze distance, and the nearest point, by setting the forward gaze distance D2 to be smaller than a predetermined distance, and includes a modified target point P3 that is outside the forward field of view but is in a position that can be followed from the target point P2. As a result, the vehicle 100 can travel while following the target path while maintaining both stability in straight lines and path following ability when turning.

[0032] Returning to Figure 2, we will continue the explanation from step S8 onwards. In step S8, the target angular velocity calculation unit 14 calculates a target angular velocity for controlling the direction of the vehicle based on the target destination calculated by the target destination calculation unit 13. In this case, the target angular velocity calculation unit 14 outputs the calculated target angular velocity to the drive control unit 16.

[0033] Next, the translational speed calculation unit 15 calculates the target translational speed of the vehicle (step S9). In this case, the translational speed calculation unit 15 outputs the calculated target translational speed to the drive control unit 16.

[0034] Subsequently, the drive control unit 16 generates a control signal to control the vehicle's speed based on the target angular velocity calculated by the target angular velocity calculation unit 14 and the target translational velocity calculated by the translational velocity calculation unit 15 (step S10). In this case, the drive control unit 16 outputs the control signal to the vehicle's steering mechanism (not shown).

[0035] According to the embodiment described above, the target point calculation unit 13 generates target point candidates, including the target point, within a predetermined distance or angle from the vehicle's position, based on the forward field of view angle in front of the vehicle, the forward gaze distance from the vehicle's own position to the target point, and the nearest neighbor point calculation unit 12 calculates the nearest neighbor point. If the target point moves outside the vehicle's forward field of view angle during the search for target point candidates, the point at that time is calculated as the target point. This allows for accurate estimation of the shape of the target course.

[0036] Furthermore, according to one embodiment, when the vehicle is traveling on a curve, the forward gaze distance is set to be small and the target point is set close to the vehicle's own position, thereby reducing the vehicle's shortcuts while improving its ability to follow the target path.

[0037] Furthermore, according to one embodiment, when the vehicle is traveling in a straight line, the forward gaze distance is set to be large and the target point is set far from the vehicle's own position, thereby improving the stability of path-matching of the target path when traveling in a straight line.

[0038] Furthermore, according to one embodiment, since processing such as differentiation of the path shape is unnecessary, the influence of shape disturbances can be reduced.

[0039] (Other embodiments) Furthermore, although the driving control device according to one embodiment was installed in the vehicle, the functions of the driving control device may also be realized by a single server.

[0040] Furthermore, in the driving control device according to one embodiment, the "parts" described above can be replaced with "means" or "circuits," etc. For example, the drive control unit can be replaced with a drive control means or a drive control circuit.

[0041] Furthermore, the program to be executed by the driving control device according to one embodiment is provided as installable or executable file data recorded on a computer-readable recording medium such as a CD-ROM, flexible disk (FD), CD-R, DVD (Digital Versatile Disk), USB medium, or flash memory.

[0042] In this specification, the flowcharts have used expressions such as "first," "then," and "next" to indicate the sequence of processes between steps. However, the order of processes necessary to implement this embodiment is not uniquely determined by these expressions. In other words, the order of processes in the flowcharts described herein can be changed within a reasonable range.

[0043] Further effects and modifications can be readily derived by those skilled in the art. Broader aspects of the present invention are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents.

[0044] Although some embodiments of this application have been described in detail above with reference to the drawings, these are illustrative examples, and the present invention can be implemented in various other forms with modifications and improvements based on the knowledge of those skilled in the art, starting with the embodiments described in the disclosure section of the present invention. [Explanation of Symbols]

[0045] 1 Driving control device; 10 Path generation unit; 11 Self-position estimation unit; 12 Nearest point calculation unit; 13 Target destination calculation unit; 14 Target angular velocity calculation unit; 15 Translational velocity calculation unit; 16 Drive control unit; 100 Vehicle

Claims

1. A driving control device equipped with a processor that controls the movement of a vehicle, The aforementioned processor, Generate the target route to the destination, The vehicle's own position is estimated, The target destination is calculated on the aforementioned target path, Based on the field of view angle in front of the vehicle and the forward gaze distance from the vehicle's own position to the target point, target point candidates including the target point are generated within a predetermined distance and angle from the vehicle's own position. Determine whether the target point is outside the forward field of view of the vehicle. If it is determined that the target point is outside the forward field of view, the forward gaze distance is set to be smaller than the predetermined distance, and a target destination is calculated that includes a new target point within the predetermined distance or angle from the vehicle's own position, and a modified target point that is outside the forward field of view and can be tracked from the new target point. Driving control device.

2. A driving control device according to claim 1, The aforementioned processor, If it is determined that the target point is not outside the forward field of view, the forward gaze distance is set to be greater than the predetermined distance, and the target destination including the new target point is calculated. Driving control device.

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