JP7275646B2 - VEHICLE TRIP CONTROL METHOD AND TRIP CONTROL DEVICE - Google Patents

Description

TECHNICAL FIELD The present invention relates to a travel control method and a travel control device for controlling travel of an own vehicle.

In a conventional vehicle running control device, when executing automatic operation control of the own vehicle, the slip angle characteristic during turning of the own vehicle is changed according to the vehicle speed and the turning radius of the target trajectory, and the vehicle body is turned toward the inside of the turn. The running of the own vehicle was controlled so as to be in an oversteer state (Patent Document 1).

WO2014/016947

However, in the vehicle running control device disclosed in Patent Document 1, the reference model for calculating the slip angle characteristic is set only for steady turning running of the own vehicle. Therefore, when the vehicle makes a transitional turn near the entrance of a corner, that is, in a corner-in section, the slip angle cannot appropriately correspond to the transitional turning state. A delay could have occurred.

The problem to be solved by the present invention is a vehicle travel control method and travel control that can appropriately control the travel of the own vehicle when the own vehicle travels in a corner-in section in a transitional turning state. to provide the equipment.

The vehicle travel control method and the travel control device according to the present invention generate a target body slip angle of the own vehicle using steady-state characteristics while the own vehicle is performing steady turning travel without traveling in a corner-in section. While the own vehicle is traveling in the corner-in section, the target vehicle body slip angle of the own vehicle that is larger than the target vehicle body slip angle during steady turning is obtained by using a transient characteristic different from the steady-state characteristic. The above problem is solved by generating an angle.

According to the vehicle travel control method and the vehicle travel control device according to the present invention, it is possible to appropriately control the travel of the own vehicle when the own vehicle is traveling in a corner-in section in a transitional turning state. It works.

1 is a block diagram showing a configuration of a vehicle cruise control system including a vehicle cruise control device according to an embodiment of the present invention; FIG. FIG. 2 is a flow chart showing an overview of travel control of a host vehicle by the travel control device shown in FIG. 1; FIG. FIG. 2 is a flow chart showing an overview of behavior control of a host vehicle by the cruise control device shown in FIG. 1; FIG. FIG. 3 is a schematic diagram showing an example of a target trajectory on which an own vehicle travels and a corner-in section on the target trajectory; FIG. 4 is a diagram showing an example of a slip angle during turning travel of the host vehicle; FIG. 2 is a flowchart showing an outline of chassis control performed by the travel control device shown in FIG. 1 when the host vehicle travels in a corner-in section; FIG. 4 is a graph showing the curvature distribution of the target track when the own vehicle performs steady turning travel; 7 is a graph showing the curvature distribution when the own vehicle travels in a transitional turning state in the corner-in section of the target trajectory. 7 is a graph showing the relationship between the average curvature of the corner-in section and the corner-in strength.

A traveling control device 100 according to an embodiment of the present invention will be described below with reference to the drawings. In particular, the outline of the overall automatic driving control by the travel control device 100 will be explained using FIGS. 8 will be used to describe in detail.

FIG. 1 is a block diagram showing the configuration of a cruise control system 101 including a cruise control device 100. As shown in FIG. The vehicle running control method and the vehicle running control device 100 according to the present invention provide running control for autonomously controlling the behaviors of the drive system actuator 11, the braking system actuator 12, and the steering system actuator 13 of the own vehicle K by a computer. A method and a cruise control device.

The traveling control device 100 is composed of one or more computers and software installed in the computers. The travel control device 100 includes a trajectory controller 8 that determines a target trajectory of the vehicle K from the current location to the destination, and a drive system actuator 11 and a braking system actuator 12 for the vehicle K based on commands from the trajectory controller 8. and a motion controller 9 that controls the steering system actuator 13 . That is, the travel control device 100 includes a ROM storing a program for exerting each function of the trajectory controller 8 and the motion controller 9, a CPU executing the program stored in the ROM, and an accessible storage device. and a RAM that functions as a As the operating circuit, an MPU, DSP, ASIC, FPGA, or the like can be used instead of or together with the CPU.

The trajectory controller 8 is based on the information from the navigation device 1, the map database 2, the vehicle position detector 3, the camera 4, the radar device 5, the vehicle speed sensor 6, and the input unit 7, the vehicle K from the current position to the destination. Calculate and determine the target trajectory of The target trajectory determined by the trajectory controller 8 is output as data including one or more lanes, a straight line, a curve with curvature, a course including a direction of travel, or a combination thereof. Further, the trajectory controller 8 calculates and outputs the required longitudinal force FxAD and the required lateral force FyAD at the current position at predetermined time intervals. On the other hand, the motion controller 9 controls the behavior of the drive system actuator 11, the braking system actuator 12, and the steering system actuator 13 of the own vehicle K based on the trajectory information determined by the trajectory controller 8. FIG.

The navigation device 1 selects from a display capable of displaying information about the current position of the vehicle K and information such as the travel route to the destination, and the input destination and the current location detected by the vehicle position detector 3. and a computer in which a program for calculating a travel route according to the selected route calculation mode is installed.

The map database 2 stores three-dimensional high-definition map information based on road shapes detected when the vehicle for data acquisition is used to travel on actual roads. The three-dimensional high-definition map information stored in the map database 2 includes map information, boundary information at each map coordinate, two-dimensional position information, three-dimensional position information, road information, road attribute information, inbound information, outbound information, It includes lane identification information, connection destination lane information, and the like. Road information and road attributes include road width, radius of curvature, shoulder structures, road traffic regulations (speed limit, lane change availability), road junctions, junctions, toll booths, lane reduction locations, service areas. / Contains information such as parking areas.

The own vehicle position detector 3 is composed of a GPS unit, a gyro sensor, a vehicle speed sensor, and the like. The own vehicle position detector 3 detects radio waves transmitted from a plurality of satellite communications by the GPS unit, periodically acquires the position information of the own vehicle K, and collects the acquired position information of the own vehicle K and the gyro sensor. and the vehicle speed acquired from the vehicle speed sensor, the current position information of the own vehicle K is periodically detected.

The camera 4 consists of an image sensor such as a CCD wide-angle camera, and is provided on the front, rear, and both sides of the vehicle K, and captures an image of the surroundings of the vehicle K to obtain image information. The camera 4 may be a stereo camera or an omnidirectional camera, and may include multiple image sensors. Camera 4 detects the road in front of own vehicle K, structures around the road, road markings, signs, other vehicles, motorcycles, bicycles, pedestrians, etc. as surrounding conditions of own vehicle K from the acquired image data. do.

Radar devices 5 are provided in front, rear, and both sides of the vehicle K, and irradiate millimeter waves or ultrasonic waves around the vehicle K to scan a predetermined range around the vehicle K. Detects surrounding obstacles such as other vehicles, motorcycles, bicycles, pedestrians, curbs on the shoulder, guardrails, walls, and embankments. For example, the radar device 5 detects the relative position (azimuth) between an obstacle and the own vehicle K, the relative speed of the obstacle, the distance from the own vehicle K to the obstacle, etc. as the surrounding conditions of the own vehicle K. FIG.

The vehicle speed sensor 6 measures the rotation speed of a driving system actuator 11 of the vehicle K such as a drive shaft, and detects the running speed of the vehicle K based on this. The input unit 7 is composed of mechanical switches, electronic switches displayed on a display, and the like, and the driver inputs information such as a destination and a decision as to whether or not to perform automatic driving.

Next, an overview of overall control by the travel control device 100 will be described with reference to FIG. 2 .
First, the travel control device 100 estimates its own position based on the position information of the own vehicle K obtained by the own vehicle position detector 3 and the map information of the map database 2 (step S1). Further, the travel control device 100 recognizes pedestrians and other obstacles around the own vehicle K using the camera 4 and the radar device 5 (step S2). Then, the information on the self position estimated in step S1 and the information on the obstacles etc. recognized in step S2 are developed and displayed on the map of the map database 2 (step S3).

Further, when a destination is input from the input unit 7 and an instruction to start autonomous driving control is input, the destination is set on the map of the map database 2 (step S4), and the navigation device 1 and the map database 2 are used. Then, route planning from the current location to the destination is performed (step S5). Then, the behavior of the own vehicle K is determined based on the information developed on the map (step S6). Specifically, for example, at each position of a plurality of intersections on the planned route, the direction in which the vehicle K turns is determined. Next, based on information such as obstacles recognized by the camera 4 or the radar device 5, drive zone planning is performed on the map of the map database 2 (step S7). Specifically, in consideration of the relationship with obstacles, the lane in which the vehicle K should travel is appropriately set at a predetermined position or at a predetermined interval on the route. Then, the trajectory controller 8 sets the target trajectory of the own vehicle K based on the inputted positional information of the current position and the destination, the set route information, the behavior of the own vehicle K and the drive zone information (step S8). Furthermore, the motion controller 9 controls the behavior of the own vehicle K so that the own vehicle K follows the target trajectory (step S9).

Next, an outline of behavior control of the host vehicle K by the motion controller 9 will be described with reference to FIG.
The control modes of the travel control device 100 of the present embodiment include an autonomous travel mode in which the driver executes autonomous travel control of the own vehicle K, and a manual mode in which the own vehicle K travels by the driver's driving operation without executing the autonomous travel control. You can select a running mode. For example, when the driver selects the autonomous driving mode of the input unit 7, execution of the autonomous driving control is started, and when the driver selects the end of the autonomous driving mode of the input unit 7, the autonomous driving control is terminated and the manual driving mode is selected. transition to Further, when the driver performs an operation intervention such as a steering wheel operation, a brake operation, or an accelerator operation during execution of the autonomous cruise control, the manual operation takes precedence over the autonomous cruise control.

Command values based on the required longitudinal force FxAD and the required lateral force FyAD generated according to the target trajectory by the trajectory controller 8 of the automatic driving hierarchy are input to the motion controller 9 (step S11). Also, a command value based on the driver's manual operation is input in parallel to the motion controller 9 (step S12). The motion controller 9 adjusts the command value based on the autonomous running mode and the command value based on the manual operation (step S13), and outputs the longitudinal force command value Fx and the lateral force command value Fy (step S14). For example, in the adjustment in step S13, it is defined that priority is given to manual operation over autonomous travel control. Then, based on the longitudinal force command value Fx and the lateral force command value Fy, the behavior of the vehicle body is controlled so that the vehicle K follows the target trajectory (step S15), and the behavior of the wheels is controlled. (step S16). As a result, the driving system actuator 11, the braking system actuator 12, and the steering system actuator 13 of the own vehicle K are operated by these controls (step S17).

The vehicle body behavior control in step S15 and the wheel behavior control in step S16 are controlled based on the longitudinal force command value Fx and lateral force command value Fy output by the motion controller 9 in step S14. In the autonomous driving mode, the required longitudinal force FxAD and the required lateral force FyAD output by the trajectory controller 8 are most reflected within the control range in which the vehicle body behavior stability and the wheel behavior stability can be optimized. , longitudinal force command value Fx and lateral force command value Fy are selected.

Further, in the vehicle body behavior control in step S15 and the wheel behavior control in step S16, the motion controller 9 controls the vehicle K to follow the target trajectory output by the trajectory controller 8 during turning travel of the vehicle K. A target vehicle body slip angle β is calculated. As shown in FIG. 4, the target vehicle body slip angle β has different slip angle characteristics when the vehicle K is making a steady turn and when the vehicle K is traveling in the corner-in section C. calculated based on

As shown in FIG. 4, the corner-in section C is a section near the entrance of a corner on the target trajectory T, and is a section during which the running state of the own vehicle K shifts from straight running to steady turning running. . The running state of the own vehicle K in the corner-in section C is a transitional turning running state.

As shown in FIG. 5, the target vehicle body slip angle β is the angle between the turning traveling direction D for the vehicle K to follow the target trajectory T and the axle direction of the vehicle K. As shown in FIG. Here, the slip angle characteristics for calculating the target vehicle body slip angle β include steady characteristics and transient characteristics. The slip angle characteristic is a steering angle command value output by the motion controller 9 based on the information of the target trajectory T, or a slip angle gain with respect to the steering angle based on the driver's manual turning operation. That is, the steady-state characteristic and the transient characteristic are slip angle characteristics representing different slip angle gains. The target vehicle body slip angle β is calculated based on the steady-state characteristics when the own vehicle K is making a steady turn. Further, when the own vehicle K is traveling in the corner-in section C, the target vehicle body slip angle β is calculated based on the characteristically distributed steady-state characteristics and transient characteristics. It is assumed that the slip angle gain based on the transient characteristics is larger than the slip angle gain based on the steady characteristics.

Further, as shown in FIG. 5, the lateral force command value Fy output by the motion controller 9 consists of a front wheel lateral force FyF acting on the front wheels 15 of the own vehicle K and a rear wheel lateral force FyF acting on the rear wheels 16 of the vehicle K. FyR and Here, the ratio of the front wheel lateral force FyF to the target vehicle body slip angle β (FyF/β) represents the front wheel cornering power value CPf, and the ratio of the rear wheel lateral force FyR to the target vehicle body slip angle β (FyR/β) is It represents the rear wheel cornering power value CPr.

A procedure for calculating the target vehicle body slip angle β by the motion controller 9 and a procedure for controlling the chassis of the own vehicle K based on the target vehicle body slip angle β will be described below with reference to FIG.

First, information on the target trajectory T output by the trajectory controller 8 is input to the motion controller 9 (step S21).
Next, the motion controller 9 determines the corner-in section C on the target trajectory T based on the information on the target trajectory T (step S22). Here, when the own vehicle K is making a steady turn, the curvature distribution of the section in which the own vehicle K is traveling becomes a Gaussian distribution centered on the curvature average R, as shown in FIG. 7A. On the other hand, as shown in FIG. 7B, the curvature distribution in the corner-in section C in which the vehicle K travels in a transitional turning state shows variation, that is, curvature bias. Therefore, the motion controller 9 determines the corner-in section C on the target trajectory T based on the variation in the curvature distribution.
In the corner-in section C, the curvature of the target trajectory T gradually increases. good too.

Next, the motion controller 9 determines the corner-in strength of the corner-in section C (step S23). As shown in FIG. 8, the corner-in strength is determined by the curvature average R' in the curvature distribution of FIG. 7B, and the larger the curvature average R', the higher the corner-in strength. The higher the corner-in strength, the sharper the vehicle K traveling in the corner-in section C turns.

Next, the motion controller 9 sets transient characteristics and steady-state characteristics, which are slip angle characteristics (step S24), and distributes the transient characteristics and the steady-state characteristics (step S25). Specifically, as shown in FIG. 5, the target vehicle body slip angle β is calculated by using the steady-state characteristics based on the steering angle command value calculated by the motion controller 9 and the steering angle command value. is calculated as a value including the slip angle βt calculated using the transient characteristic. The target vehicle body slip angle β when the own vehicle K is traveling in the corner-in section C is greater than the target vehicle body slip angle β when the own vehicle K is making a steady turn without traveling in the corner-in section C. is also big. Note that the slip angle βs and the slip angle βt may be calculated based on the steering angle information by the driver's operation in the manual travel mode.

Next, the motion controller 9 calculates the rear wheel cornering power value CPr required to achieve the target vehicle body slip angle β (step S27). The motion controller 9 increases the target vehicle body slip angle β by reducing the rear wheel cornering power value CPr, and adjusts the vehicle K so that the vehicle K turns in an oversteer state in the corner-in section C. can be controlled. Further, the motion controller 9 limits the rate of change of the rear wheel cornering power value CPr in order to prevent sudden changes in the rear wheel cornering power value CPr due to changes in the slip angle characteristics (step S28).

Further, the motion controller 9 determines whether or not the vehicle speed of the own vehicle K is equal to or higher than the limit vehicle speed _VL (step S29). When the vehicle speed of the own vehicle K is equal to or higher than the vehicle speed limit _VL and the ratio of the rear wheel cornering power value CPr to the front wheel cornering power value CPf (CPr/CPf) is equal to or less than a predetermined value N, the spin of the own vehicle K is controlled. It may provoke. Therefore, in such a case, the motion controller 9 reduces the front wheel cornering power value CPf so that the ratio of the rear wheel cornering power value CPr to the front wheel cornering power value CPf (CPr/CPf) exceeds a predetermined value N. (step S30). That is, the "predetermined value N" in the ratio (CPr/CPf) of the rear wheel cornering power value CPr to the front wheel cornering power value CPf is the spin rate of the vehicle K even if the vehicle speed of the vehicle K is equal to or higher than the vehicle speed limit _VL . is set as the minimum value that does not induce

Based on the rear wheel cornering power value CPr and the front wheel cornering power value CPf calculated in steps S21 to S30, the motion controller 9 operates the drive system actuator 11 and the braking system actuator 12 of the host vehicle K according to a predetermined reference model. And the steering system actuator 13 is controlled to execute chassis control (step S31). As a result, the target vehicle body slip angle β calculated in step S26 is realized. The target vehicle body slip angle β when the own vehicle K is traveling in the corner-in section C is greater than the target vehicle body slip angle β when the own vehicle K is making a steady turn without traveling in the corner-in section C. is large, the vehicle K turns in the corner-in section C in an oversteer state.

As described above, in this embodiment, the motion controller 9 of the cruise control device 100 of this embodiment determines a section of the target trajectory T corresponding to the corner-in section C. FIG. While the own vehicle K is making a steady turn without traveling in the corner-in section C, the steady-state characteristic is used to generate the target vehicle body slip angle β of the own vehicle K, and the own vehicle K passes through the corner-in section C. While driving, the transient characteristics are used to generate the target vehicle body slip angle β. As a result, the slip angle characteristic is changed between when the own vehicle K is turning in a steady turning state and when it is traveling in the corner-in section C in a transient turning state, and the slip angle characteristic is changed according to the turning conditions. A suitable slip angle can be generated. Therefore, when the own vehicle K is traveling in the corner-in section C in a transitional turning state, the traveling of the own vehicle K can be controlled more appropriately. The invention of the present application can also be applied to generating a travel locus for causing the own vehicle K to travel, such as automatic driving. When generating a travel locus for the own vehicle K to travel, as in automatic driving, the position in which the own vehicle K travels in the travel lane is determined. can be used to determine corner-in. Therefore, by applying the present invention to a system that generates a running locus for running the own vehicle K, such as automatic driving, it is possible to accurately specify the scene in which the vehicle K is to be turned using the corner-in characteristics. An appropriate vehicle attitude can be generated along the travel locus of K.

Further, the target vehicle body slip angle β when the own vehicle K is traveling in the corner-in section C is the target vehicle body slip angle greater than β. As a result, while the vehicle K is traveling in the corner-in section C, the vehicle K is oversteered. Therefore, the turning performance of the vehicle K traveling in the corner-in section C is improved, and the vehicle K can turn along the target trajectory T more quickly.

Also, the motion controller 9 determines the corner-in section C based on the change in curvature of the target trajectory T or the variation in curvature. This makes it possible to more accurately determine which region on the target trajectory T is the corner-in section C. FIG.

Further, the motion controller 9 calculates the corner-in strength of the corner-in section C based on the curvature average R' of the corner-in section C. Accordingly, a more appropriate target vehicle body slip angle β can be generated according to the corner-in strength of the corner-in section C.

Further, while the vehicle K is running in the corner-in section C, the motion controller 9 generates the target vehicle body slip angle β using the steady-state characteristic and the transient characteristic. Furthermore, in calculating the target vehicle body slip angle β, the steady-state characteristic and the transient characteristic are distributed according to the corner-in strength. As a result, a more appropriate target vehicle body slip angle β can be generated using the steady-state characteristic and the transient characteristic according to the corner-in strength of the corner-in section C.

Further, the motion controller 9 calculates a rear wheel cornering power value CPr required to generate the target vehicle body slip angle β, and based on the rear wheel cornering power value CPr, the driving system actuator 11, the braking system actuator 12, and the The steering system actuator 13 is controlled, and the chassis control of the own vehicle K is performed. As a result, the target vehicle body slip angle β generated by the motion controller 9 can be achieved more reliably.

Further, the rear wheel cornering power value CPr output by the motion controller 9 is provided with a change rate limit. As a result, a sudden change in the rear wheel cornering power value CPr that accompanies a change in the slip angle characteristic can be suppressed, and the behavior of the own vehicle K can be stabilized.

In addition, the motion controller 9 is controlled when the vehicle speed is equal to or higher than a predetermined limit vehicle speed _VL and the ratio of the rear wheel cornering power value CPr to the front wheel cornering power value CPf (CPr/CPf) is equal to or lower than a predetermined value N. At some point, the front wheel cornering power value CPf is reduced. As a result, it is possible to prevent a situation in which the own vehicle K becomes excessively oversteered and a spin is induced.

DESCRIPTION OF SYMBOLS 100... Travel control apparatus 8... Trajectory controller 9... Motion controller 11... Driving system actuator 12... Braking system actuator 13... Steering system actuator C... Corner-in section K... Own vehicle T... Target trajectory β... Target body slip angle CPr ... Rear wheel cornering power value CPf ... Front wheel cornering power value R' ... Curvature average

Claims (9)

A travel control device comprising: a trajectory controller that determines a target trajectory for the vehicle from its current location to a destination; and a motion controller that controls actuators of the vehicle so that the vehicle follows the target trajectory. In the vehicle cruise control method for executing the cruise control of the own vehicle,
using the motion controller,
determining a corner-in section, which is a section in which the running state of the vehicle shifts from straight running to steady turning running, on the target track;
generating a target vehicle body slip angle of the own vehicle using a slip angle characteristic including a steady state characteristic while the own vehicle is performing steady turning without traveling in the corner-in section;
While the host vehicle is traveling in the corner-in section, slip angle characteristics including transient characteristics that are different from the steady-state characteristics are used to determine whether the vehicle body slip angle is lower than the target vehicle body slip angle during steady-state turning. generating the target vehicle body slip angle of the host vehicle that is large ;
A vehicle travel control method comprising: controlling the actuator based on the target vehicle body slip angle. The target vehicle body slip angle when the own vehicle is traveling in the corner-in section is higher than the target vehicle body slip angle when the own vehicle is making a steady turn without traveling in the corner-in section. is also large,
2. The vehicle travel control method according to claim 1, wherein said own vehicle is in an oversteer state while said own vehicle is traveling in said corner-in section. 3. The vehicle running control method according to claim 1, wherein said motion controller is used to determine said corner-in section on said target trajectory based on changes in curvature or variations in curvature of said target trajectory. The vehicle running control method according to any one of claims 1 to 3, wherein the motion controller is used to calculate the corner-in strength of the corner-in section based on the curvature average of the corner-in section. using the motion controller,
generating the target vehicle body slip angle using the steady-state characteristic and the transient characteristic while the own vehicle is traveling in the corner-in section;
5. The vehicle running control method according to claim 4, wherein the steady-state characteristic and the transient characteristic are allocated according to the corner-in strength in calculating the target vehicle body slip angle. Claims 1 to 5, wherein the motion controller is used to calculate a rear wheel cornering power value required to achieve the target vehicle body slip angle, and the actuator is controlled based on the rear wheel cornering power value. The vehicle travel control method according to any one of Claims 1 to 3. 7. The vehicle running control method according to claim 6, wherein the rear wheel cornering power value output by the motion controller is provided with a change rate limit. When the vehicle speed of the own vehicle is equal to or higher than a predetermined vehicle speed limit and the ratio (CPr/CPf) of the rear wheel cornering power value (CPr) to the front wheel cornering power value (CPf) is equal to or less than a predetermined value, the motion 8. The vehicle cruise control method according to claim 6, wherein a controller is used to reduce the front wheel cornering power value. a trajectory controller that determines a target trajectory of the own vehicle from the current location to the destination;
a motion controller that controls an actuator of the own vehicle so that the own vehicle follows the target trajectory and travels;
The motion controller is
determining a corner-in section, which is a section in which the running state of the vehicle shifts from straight running to steady turning running, on the target track;
generating a target vehicle body slip angle of the own vehicle using a slip angle characteristic including a steady state characteristic while the own vehicle is performing steady turning without traveling in the corner-in section;
While the host vehicle is traveling in the corner-in section, slip angle characteristics including transient characteristics that are different from the steady-state characteristics are used to set the slip angle to be lower than the target vehicle body slip angle during steady-state turning. generating the target vehicle body slip angle of the host vehicle that is large ;
A vehicle travel control device that controls the actuator based on the target vehicle body slip angle.

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