Vehicle control device

Abstract

The invention relates to a vehicle control apparatus. A vehicle control device that causes a vehicle to travel along a target route comprises: a vehicle position estimation unit that estimates the position of the vehicle after a predetermined time from the current start and outputs the estimated position; a yaw angle deviation calculation unit that calculates a yaw angle deviation, which is a deviation between an actual yaw angle of the vehicle and a target yaw angle corresponding to the target route, on the basis of the target route and the estimated position; a lateral deviation calculation unit that calculates a lateral deviation, which is a deviation between an actual lateral position of the vehicle and a target lateral position corresponding to the target route, on the basis of the target route and the estimated position; a target steering angle calculation unit that calculates a target steering angle on the basis of a target curvature based on the target path, the yaw angle deviation, and the lateral deviation; and a control unit that controls steering on the basis of the target steering angle when the vehicle is driven.

Description

Technical Field

[0001] Embodiments of the present invention relate to a vehicle control device. Background Art

[0002] Conventionally, technology has been developed to enable vehicles to travel along a target path. This technology involves, for example, performing feed-forward (FF) control using a target curvature based on the target path, and feedback (FB) control using the vehicle's lateral deviation and yaw angle deviation when the vehicle is traveling on a curve.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-30482

[0004] Patent Document 2: Japanese Patent Application Laid-Open No. 2016-199080

[0005] Patent Document 3: Japanese Patent Application Laid-Open No. 2018-39293

[0006] However, the above-mentioned conventional technology sometimes suffers from poor vehicle path following performance. One reason for this is that FB control using lateral deviation and yaw angle deviation may cause delays due to control delays caused by control cycles and CAN (Controller Area Network) cycles. Summary of the Invention

[0007] Therefore, the present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a vehicle control device that can improve the path following performance when causing a vehicle to travel along a target path.

[0008] To solve the above-mentioned problems, a vehicle control device according to an embodiment is a vehicle control device for causing a vehicle to travel along a target path, and includes: a vehicle position estimating unit that estimates the position of the vehicle after a specified time from the current time and outputs the estimated position; a yaw angle deviation calculating unit that calculates, based on the target path and the estimated position, a yaw angle deviation, which is a deviation between the actual yaw angle of the vehicle and a target yaw angle corresponding to the target path; a lateral deviation calculating unit that calculates, based on the target path and the estimated position, a lateral deviation, which is a deviation between the actual lateral position of the vehicle and a target lateral position corresponding to the target path; a target steering angle calculating unit that calculates a target steering angle based on a target curvature based on the target path, the yaw angle deviation, and the lateral deviation; and a control unit that controls steering based on the target steering angle when causing the vehicle to travel.

[0009] According to the above configuration, the path following performance of the vehicle can be improved by calculating the yaw angle deviation and the lateral deviation based on the estimated position of the vehicle a predetermined time from the present time and using them to calculate the target steering angle.

[0010] Furthermore, in the vehicle control device, the vehicle position estimating unit estimates the position of the vehicle after the predetermined time from the current time based on the current position of the vehicle and the moving speed and moving direction of the vehicle, and outputs the estimated position.

[0011] According to the above configuration, specifically, the position of the vehicle a predetermined time from the present time can be estimated based on the current position of the vehicle and the moving speed and moving direction of the vehicle.

[0012] In addition, in the vehicle control device, the steering response delay matching time of the vehicle's own vehicle position estimation unit is taken into consideration in advance to calculate the above-mentioned current position of the above-mentioned vehicle. The longer the above-mentioned steering response delay matching time is, the smaller the value used by the above-mentioned vehicle position estimation unit as the above-mentioned prescribed time.

[0013] According to the above configuration, a more appropriate value can be used as the predetermined time, and the path following performance of the vehicle can be further improved.

[0014] Furthermore, in the vehicle control device, the vehicle position estimating unit uses a target vehicle speed as the moving speed.

[0015] According to the above configuration, since the target vehicle speed is more stable than the actual vehicle speed, the estimation result of the vehicle position can be made more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is an exemplary perspective view showing a state in which a portion of the vehicle interior of the vehicle according to the embodiment is seen through.

[0017] Figure 2 is an exemplary top view (bird's-eye view) of the vehicle according to the embodiment.

[0018] Figure 3 This is a diagram showing an example of an instrument panel of a vehicle according to an embodiment, as viewed from the rear of the vehicle.

[0019] Figure 4 is an exemplary block diagram of the structure of a vehicle control system according to an embodiment.

[0020] Figure 5 This is a diagram showing the relationship between control delay and predicted time according to an embodiment.

[0021] Figure 6 It is an explanatory diagram of the yaw angle deviation and the lateral deviation according to the embodiment.

[0022] Figure 7 This is a block diagram of steering control in an embodiment.

[0023] Figure 8A This is a graph showing the lateral deviation and yaw angle deviation at different predicted times when the vehicle moves forward in the embodiment.

[0024] Figure 8B This is a graph showing the lateral deviation and yaw angle deviation at different predicted times when the vehicle moves forward in the embodiment.

[0025] Figure 9A This is a graph showing the lateral deviation and yaw angle deviation at different predicted times when the vehicle moves backward in the embodiment.

[0026] Figure 9B This is a graph showing the lateral deviation and yaw angle deviation at different predicted times when the vehicle moves backward in the embodiment. DETAILED DESCRIPTION

[0027] The following describes exemplary embodiments of the present invention. The structures of the embodiments described below, as well as the functions, results, and effects resulting from these structures, are merely examples. The present invention can also be implemented using structures other than those disclosed in the following embodiments, and can provide at least one of the various effects and derivative effects derived from the basic structures.

[0028] The vehicle 1 of this embodiment can be, for example, an automobile driven by an internal combustion engine (not shown), i.e., an internal combustion engine vehicle; an automobile driven by an electric motor (not shown), i.e., an electric vehicle, a fuel cell vehicle, etc.; a hybrid vehicle driven by both of these; or an automobile equipped with other drive sources. Furthermore, the vehicle 1 can be equipped with various transmissions and various devices, such as systems and components, required to drive the internal combustion engine and the electric motor. Furthermore, the type, number, and layout of the devices related to driving the wheels 3 of the vehicle 1 can be variously configured.

[0029] Figure 1 This is an exemplary perspective view showing a state in which a portion of the vehicle interior of the vehicle according to the embodiment is seen through. Figure 2 is an exemplary top view (bird's-eye view) of the vehicle according to the embodiment.

[0030] As in Figure 1 As shown in the figure, the vehicle body 2 constitutes a vehicle cabin 2a in which passengers (not shown) sit. In the vehicle cabin 2a, a steering control unit 4, an accelerator control unit 5, a brake control unit 6, a gear shift control unit 7, etc. are provided in the vehicle cabin 2a in a state facing a driver's seat 2b as a passenger.

[0031] The steering unit 4 is, for example, a steering wheel protruding from the instrument panel 24. The accelerator unit 5 is, for example, an accelerator pedal located under the driver's feet. The brake unit 6 is, for example, a brake pedal located under the driver's feet. The shift unit 7 is, for example, a shift lever protruding from the center console. However, the steering unit 4, accelerator unit 5, brake unit 6, and shift unit 7 are not limited to these.

[0032] In addition, a display device 8 serving as a display output unit and a sound output device 9 serving as a sound output unit are provided in the vehicle interior 2a. The display device 8 is, for example, an LCD (liquid crystal display), an OELD (organic electroluminescent display), or the like. The sound output device 9 is, for example, a speaker. In addition, the display device 8 is covered by a transparent operation input unit 10 such as a touch panel. Passengers can recognize the image displayed on the display screen of the display device 8 via the operation input unit 10. In addition, passengers can perform operation input by touching, pressing, or moving the operation input unit 10 with a finger or the like at a position corresponding to the image displayed on the display screen of the display device 8.

[0033] The display device 8, audio output device 9, and operation input unit 10 are provided, for example, in a monitoring device 11 located in the center of the instrument panel 24 in the vehicle width direction, i.e., in the left-right direction. The monitoring device 11 may include an operation input unit (not shown), such as a switch, knob, joystick, or button. Furthermore, an audio output device (not shown) may be provided at a different location within the vehicle interior 2a than the monitoring device 11. Furthermore, audio can be output from the audio output device 9 of the monitoring device 11 and from other audio output devices. Furthermore, the monitoring device 11 may also function as a navigation system or an audio system, for example.

[0034] In addition, a display device 12 (see FIG. 1 ) is provided in the vehicle interior 2a, which is different from the display device 8. Figure 3 ). Figure 3 FIG. 1 is a diagram showing an example of a vehicle instrument panel according to an embodiment, as viewed from the rear of the vehicle. Figure 3 As shown in the example, the display device 12 is provided on the instrument panel 25 of the instrument panel 24, and is located approximately in the center of the instrument panel 25, between the speed display portion 25a and the rotation speed display portion 25b. The screen size of the display device 12 is smaller than the screen size of the display device 8 ( Figure 1 ) in size. Display device 12 can primarily display images of information related to driving control of vehicle 1 (e.g., parking assist control). The amount of information displayed on display device 12 may be less than that displayed on display device 8. Display device 12 is, for example, an LCD or OLED. Furthermore, information displayed on display device 12 may also be displayed on display device 8.

[0035] In addition, if Figure 1 as well as Figure 2 As shown in the example, the vehicle 1 is a four-wheeled vehicle having two left and right front wheels 3F and two left and right rear wheels 3R. The four wheels 3 are all configured to be steerable.

[0036] Figure 4 FIG. 1 is an exemplary block diagram of the structure of a vehicle control system according to an embodiment. Figure 4 As shown, the vehicle 1 has an EPS13 (electric power steering system) for steering at least two wheels 3. The EPS13 has an actuator 13a and a torque sensor 13b. The EPS13 is electrically controlled by an ECU14 (electronic control unit) or the like to operate the actuator 13a. In the following description, the EPS13 is an electric power steering system, an SBW (steer by wire) system, or the like. The EPS13 applies torque, i.e., auxiliary torque, to the steering control unit 4 through the actuator 13a to supplement the steering force, or steers the wheel 3 through the actuator 13a. In this case, the actuator 13a can steer one wheel 3 or multiple wheels 3. In addition, the torque sensor 13b detects, for example, the torque applied by the driver to the steering control unit 4.

[0037] In addition, if Figure 2 As illustrated, as a plurality of photographing units 15, four photographing units 15a to 15d are provided on the vehicle body 2, for example. The photographing unit 15 is, for example, a digital camera with built-in photographing elements such as a CCD (charge coupled device) and a CIS (CMOS image sensor). The photographing unit 15 can output moving image data at a specified frame rate. The photographing unit 15 has a wide-angle lens or a fisheye lens, and can photograph a range of, for example, 140° to 190° in the horizontal direction. In addition, the optical axis of the photographing unit 15 is set to face obliquely downward. Therefore, the photographing unit 15 sequentially photographs the external environment surrounding the vehicle body 2, including the road surface on which the vehicle 1 can move and the area where the vehicle 1 can park, and outputs it as photographed image data.

[0038] The imaging unit 15a is, for example, located at the end 2e on the rear side of the vehicle body 2 and is provided on the wall below the door 2h of the rear trunk. The imaging unit 15b is, for example, located at the end 2f on the right side of the vehicle body 2 and is provided on the right door mirror 2g. The imaging unit 15c is, for example, located at the front side of the vehicle body 2, that is, at the end 2c on the front side in the front-to-rear direction of the vehicle, and is provided on the front bumper, etc. The imaging unit 15d is, for example, located at the left side of the vehicle body 2, that is, at the end 2d on the left side in the vehicle width direction, and is provided on the door mirror 2g which is a protruding portion on the left side. The ECU 14 performs calculation processing and image processing based on the image data obtained by the multiple imaging units 15, and is capable of generating an image with a wider field of view, or generating a virtual bird's-eye view image (top view image) of the vehicle 1 viewed from above.

[0039] Furthermore, the ECU 14 recognizes a dividing line or the like indicated on the road surface around the vehicle 1 from the image of the imaging unit 15 , and detects (extracts) a parking space indicated by the dividing line or the like.

[0040] In addition, if Figure 1 as well as Figure 2 As shown, as a plurality of ranging units 16 and 17, four ranging units 16a to 16d and eight ranging units 17a to 17h are provided on the vehicle body 2, for example. The ranging units 16 and 17 are, for example, sonars that emit ultrasonic waves and capture their reflected waves. Sonars can also be called sonar sensors or ultrasonic detectors. The ECU 14 can use the detection results of the ranging units 16 and 17 to determine the presence of objects such as obstacles around the vehicle 1 and the distance to such objects. In other words, the ranging units 16 and 17 are examples of detection units that detect objects. Furthermore, the ranging unit 17 can be used, for example, to detect objects at relatively close distances, while the ranging unit 16 can be used, for example, to detect objects at relatively long distances that are farther than the ranging unit 17. Furthermore, the ranging unit 17 can be used, for example, to detect objects in front of and behind the vehicle 1, while the ranging unit 16 can be used to detect objects to the sides of the vehicle 1.

[0041] In addition, if Figure 4 As shown, in the vehicle control system 100 that causes the vehicle to travel along a target path, in addition to the ECU 14, the monitoring device 11, the EPS 13, the ranging units 16 and 17, etc., the braking system 18, the steering angle sensor 19, the accelerator sensor 20, the shift sensor 21, the wheel speed sensor 22, etc. are electrically connected via the in-vehicle network 23 which serves as an electrical communication line.

[0042] The in-vehicle network 23 is configured, for example, as a CAN (controller area network). The ECU 14 controls the EPS 13, the brake system 18, and the like by sending control signals via the in-vehicle network 23. Furthermore, the ECU 14 can receive detection results from the torque sensor 13b, the brake sensor 18b, the rotational angle sensor 19, the distance measuring unit 16, the distance measuring unit 17, the accelerator sensor 20, the shift sensor 21, the wheel speed sensor 22, and other sensors, as well as operation signals from the operation input unit 10 and other sensors, via the in-vehicle network 23.

[0043] like Figure 4 As shown, the ECU 14 includes, for example, a CPU 14 a (central processing unit), a ROM 14 b (read only memory), a RAM 14 c (random access memory), a display control unit 14 d , a sound control unit 14 e , and an SSD 14 f (solid state drive, flash memory).

[0044] The CPU 14a can perform various computational processes and controls, such as image processing related to images displayed on the display devices 8 and 12, determination of the target position of the vehicle 1, calculation of the movement path of the vehicle 1, determination of the presence or absence of interference with an object, automatic control of the vehicle 1, and release of automatic control. The CPU 14a can read a program installed and stored in a nonvolatile storage device such as the ROM 14b and perform computational processes in accordance with the program.

[0045] The RAM 14c temporarily stores various data used in the calculations of the CPU 14a. Furthermore, the display control unit 14d, within the calculations of the ECU 14, primarily performs image processing using image data obtained by the imaging unit 15 and synthesizes image data displayed on the display devices 8 and 12. Furthermore, the sound control unit 14e, within the calculations of the ECU 14, primarily performs processing of sound data output by the sound output device 9. The SSD 14f is a rewritable, non-volatile storage unit that can store data even when the power to the ECU 14 is turned off.

[0046] Furthermore, the CPU 14a, ROM 14b, RAM 14c, and the like can be integrated into the same package. Furthermore, the ECU 14 may utilize a DSP (digital signal processor) or other logic processor, logic circuit, or the like in place of the CPU 14a. Furthermore, an HDD (hard disk drive) may be provided in place of the SSD 14f, or the SSD 14f and HDD may be provided separately from the ECU 14.

[0047] The brake system 18 includes, for example, an ABS (anti-lock brake system) that prevents brake lock, an electronic stability control (ESC) system that prevents the vehicle 1 from slipping when turning, an electric brake system that enhances braking force (performs brake assist), or a brake-by-wire (BBW) system. The brake system 18 applies braking force to the wheels 3 and, consequently, to the vehicle 1 via an actuator 18a.

[0048] Furthermore, the brake system 18 can detect brake lock, wheel 3 spin, or signs of side slip based on the rotational difference between the left and right wheels 3, and can perform various controls. The brake sensor 18b is, for example, a sensor that detects the position of the movable portion of the brake operating unit 6. The brake sensor 18b can detect the position of the brake pedal, which is the movable portion of the brake operating unit 6. The brake sensor 18b includes a displacement sensor.

[0049] The rotation angle sensor 19 is a sensor that detects the steering amount of the steering control unit 4, such as a steering wheel. The rotation angle sensor 19 is configured using, for example, a Hall effect element. The ECU 14 obtains information from the rotation angle sensor 19 regarding the driver's steering amount on the steering control unit 4 and the steering amount of each wheel 3 during automatic steering, and performs various control operations. Furthermore, the rotation angle sensor 19 detects the rotation angle of the rotating parts of the steering control unit 4. The rotation angle sensor 19 is an example of an angle sensor.

[0050] The accelerator sensor 20 is a sensor that detects the position of a movable portion of the accelerator operating unit 5. The accelerator sensor 20 can detect the position of an accelerator pedal that is a movable portion of the accelerator operating unit 5. The accelerator sensor 20 includes a displacement sensor.

[0051] The shift sensor 21 is a sensor that detects the position of a movable portion of the shift operating unit 7. The shift sensor 21 can detect the position of a lever, arm, button, or the like, which is a movable portion of the shift operating unit 7. The shift sensor 21 may include a displacement sensor or may be configured as a switch.

[0052] The wheel speed sensor 22 detects the rotational speed of the wheel 3 and the number of revolutions per unit time. The wheel speed sensor 22 outputs the number of wheel speed pulses representing the detected rotational speed as a sensor value. The wheel speed sensor 22 can be configured using, for example, a Hall effect element. The ECU 14 calculates the movement amount of the vehicle 1 and other parameters based on the sensor values ​​obtained from the wheel speed sensor 22 and performs various control operations. The wheel speed sensor 22 may also be included in the brake system 18. In this case, the ECU 14 obtains the detection results of the wheel speed sensor 22 via the brake system 18.

[0053] The structures, arrangements, electrical connection forms, and the like of the various sensors and actuators described above are merely examples, and various settings (changes) are possible.

[0054] In the present embodiment, the ECU 14 realizes at least a part of the functions as a vehicle control device through the cooperation of hardware and software (control program).

[0055] Below, first refer to Figures 5 to 7 A technique for improving the path following performance when causing such a vehicle 1 to travel along a target path will be described.

[0056] Figure 5 This is a diagram showing the relationship between control delay and predicted time according to an embodiment. Figure 6 It is an explanatory diagram of the yaw angle deviation and the lateral deviation according to the embodiment. Figure 7 This is a block diagram of steering control in an embodiment.

[0057] Figure 7 The components 201 to 209 shown are, for example, ECU 14 ( Figure 4 ) function.

[0058] The vehicle position estimation unit 201 (vehicle position estimation unit) estimates the position of the vehicle 1 after a predetermined time from the current time based on controlling the delay time and using information of a predetermined time set in advance, and outputs the estimated position.

[0059] here, Figure 5 Reference symbol T1 denotes a control delay caused by the control cycle, CAN cycle, and other factors. In conventional technology, one of the reasons for poor path following performance of vehicle 1 is that the FB control using lateral deviation and yaw angle deviation is delayed due to this control delay (reference symbol T1). Specifically, conventional technology uses the current position of vehicle 1 to calculate lateral deviation and yaw angle deviation and then performs FB control.

[0060] Therefore, in this embodiment, when calculating the lateral deviation and yaw angle deviation of the vehicle 1, the current position of the vehicle 1 is not used, but the estimated position of the vehicle 1 a predetermined time from the current position is used. Hereinafter, the predetermined time set in this case will also be referred to as "predicted time" (reference symbol T3).

[0061] In addition, Figure 5 Although the time obtained by adding the predicted time (reference symbol T3) and the steering response delay matching time (reference symbol T2) during vehicle position estimation is equal to the control delay time (reference symbol T1), this is because the steering response delay time (tire angle response delay time) during the steering control of vehicle 1 is taken into account in advance during vehicle position estimation. Therefore, the vehicle position estimation unit 201 uses a smaller value as the predicted time as the steering response delay time during vehicle position estimation increases.

[0062] In addition, the vehicle position estimation unit 201 estimates the position of the vehicle 1 after a predetermined time from the current time based on the current position of the vehicle 1, the moving speed of the vehicle 1, and the moving direction of the vehicle 1, and outputs the estimated position. Figure 6 As shown, with the current position of the vehicle 1 (reference symbol P1) as a reference, the destination of movement of a distance obtained by multiplying the predicted time by the vehicle speed is set as the predicted position (reference symbol P2) (estimated position).

[0063] The vehicle position estimation unit 201 may use the actual vehicle speed or the target vehicle speed as the moving speed.

[0064] Furthermore, the vehicle position estimation unit 201 may use a first predetermined time set in advance for forward movement of the vehicle 1 as the predetermined time, or may use a second predetermined time set in advance for backward movement of the vehicle 1 as the predetermined time.

[0065] Furthermore, the vehicle position estimating unit 201 may assume that the vehicle 1 is moving in a straight line during the above estimation, but may also assume that the vehicle 1 is moving in a curved line. Specifically, the vehicle position estimating unit 201 may also use at least one of the current curvature of the vehicle 1, the target curvature, and the steering angle of the vehicle 1 as the case where the vehicle 1 is moving in a curved line, to estimate the position of the vehicle 1 a predetermined time from the current time, and output the estimated position.

[0066] Furthermore, the vehicle position estimation unit 201 collectively outputs various information such as wheel speed, steering angle, and vehicle speed in addition to the estimated position of the vehicle 1 .

[0067] The deviation calculation unit 202 (yaw angle deviation calculation unit) calculates the target path based on the target path ( Figure 6B) and the inferred position ( Figure 6 The actual yaw angle of the vehicle 1 is calculated by using the reference symbol P2 (predicted position) Figure 6 V2) and the target path ( Figure 6 The target yaw angle ( Figure 6 The deviation of the yaw angle ( V1 ) is the deviation of the yaw angle ( Figure 6 In addition, in Figure 6 In FIG. 1 , points A1 and A2 are the feet of perpendicular lines drawn from the reference points of the current position (P1) and the predicted position (P2) of the vehicle 1 to the target path (B).

[0068] In addition, the deviation calculation unit 202 (lateral deviation calculation unit) calculates the target path ( Figure 6 B) and the inferred position ( Figure 6 The actual lateral position of the vehicle 1 ( Figure 6 The reference point of the reference mark P2) corresponds to the target path ( Figure 6 The deviation of the target lateral position (the point of the reference numeral A2) is the lateral deviation ( Figure 6 ey_prv).

[0069] The multiplication unit 203 multiplies the lateral deviation output from the deviation calculation unit 202 by the gain Ke.

[0070] The multiplication unit 204 multiplies the yaw angle deviation output from the deviation calculation unit 202 by a gain Kθ.

[0071] The lateral deviation and yaw angle deviation are calculated by the deviation calculation unit 202 with appropriate signs (for example, the signs + / - are reversed when the vehicle is moving forward and when the vehicle is moving backward) according to the vehicle's traveling direction.

[0072] Addition unit 205 adds the value output from multiplication unit 203 and the value output from multiplication unit 204 .

[0073] The adder-subtractor 206 adds the input target curvature (target curvature of the target path) and subtracts the value output from the adder 205 .

[0074] The target steering angle calculation unit 207 calculates the target steering angle based on the target curvature output from the addition and subtraction unit 206 and the curvature / steering angle map 2071. The curvature / steering angle map 2071 is information indicating the relationship between the target curvature and the steering angle.

[0075] The filter processing unit 208 performs smoothing processing (low-pass filtering processing) on ​​the target steering angle output from the target steering angle calculation unit 207. This smoothing processing removes noise and smoothes the change in the steering angle.

[0076] The protection processing unit 209 performs protection processing on the target steering angle output from the filtering processing unit 208 so as not to exceed a preset maximum steering angle.

[0077] When driving the vehicle 1 , the EPS 13 controls the steering based on the target steering angle output from the protection processing unit 209 .

[0078] Next, refer to Figure 8A 、 Figure 8B 、 Figure 9A 、 Figure 9B Effects of the vehicle 1 according to the present embodiment will be described. Figure 8A 、 Figure 8B This is a graph showing the lateral deviation and yaw angle deviation at different predicted times when the vehicle is moving forward in the embodiment. The horizontal axis represents time. Figure 9A 、 Figure 9B This is a graph showing the lateral deviation and yaw angle deviation at different predicted times when the vehicle moves backward in the embodiment.

[0079] exist Figure 8A 、 Figure 9A In the figure, the vertical axis is the lateral deviation. Figure 8B 、 Figure 9B The vertical axis represents the yaw angle deviation. The graphs G1 to G4 respectively represent the cases where the prediction time is 0 ms (milliseconds), 12 ms, 24 ms, and 36 ms.

[0080] according to Figure 8A 、 Figure 8B It can be seen that when the vehicle is moving forward, the deviations under the reference symbol G4 (when the predicted time is 36ms) are close to zero, and the effect is significant. Figure 9A 、 Figure 9B It can be seen that when the vehicle moves backward, the deviations under reference symbol G2 (predicted time is 12 ms) are close to zero, and the effect is significant.

[0081] according to Figure 8A 、 Figure 8B 、 Figure 9A 、 Figure 9B It can be seen that the method of this embodiment improves the path following performance of the vehicle 1. In addition, it can be seen that it is often better to use different values ​​as the predetermined time when the vehicle 1 is moving forward and when it is moving backward.

[0082] As described above, according to the vehicle 1 of this embodiment, the path following performance of the vehicle 1 can be improved by calculating the yaw angle deviation and the lateral deviation based on the estimated position of the vehicle a predetermined time from the present time and using them to calculate the target steering angle.

[0083] Specifically, the vehicle position estimation unit 201 can estimate the position of the vehicle 1 a predetermined time from the current time based on the current position of the vehicle 1 and the moving speed and moving direction of the vehicle.

[0084] Furthermore, the vehicle position estimation unit 201 uses a smaller value as the predetermined time as the steering response delay matching time used for estimating the position of the vehicle 1 increases, thereby being able to use a more appropriate value as the predetermined time and further improving the path following performance of the vehicle 1 .

[0085] Furthermore, if the vehicle position estimation unit 201 uses the target vehicle speed as the moving speed, the target vehicle speed is more stable than the actual vehicle speed, and thus the position estimation result of the vehicle 1 can be made more stable.

[0086] Furthermore, by using a first predetermined time set in advance for forward movement and a second predetermined time set in advance for reverse movement as the predetermined time, it is possible to cope with a situation where appropriate values ​​of the predetermined time differ between forward movement and reverse movement of the vehicle 1 .

[0087] Furthermore, when the vehicle 1 is traveling on a curve, the position of the vehicle 1 a predetermined time from the present time is estimated as if the vehicle 1 is moving in a curve, thereby obtaining a more accurate calculation result.

[0088] Furthermore, the program executed in vehicle 1 may be provided as a computer program product by storing it in an installable or executable format on a computer-readable storage medium such as a CD-ROM, CD-R, memory card, DVD (Digital Versatile Disk), or floppy disk (FD). Alternatively, the program may be stored on a computer connected to a network such as the Internet and provided by downloading it via the network. Alternatively, the program may be provided or distributed via a network such as the Internet.

[0089] While the embodiments of the present invention have been described above, these embodiments are provided as examples and are not intended to limit the scope of the invention. New embodiments may be implemented in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. Such embodiments and their variations are intended to be within the scope and spirit of the invention, and are encompassed by the invention described in the technical proposal and its equivalents.

[0090] [Summary of this embodiment]

[0091] This embodiment has at least the following structures.

[0092] The ECU 14 (vehicle control unit) that causes the vehicle 1 to travel along the target path includes: a vehicle position estimation unit 201 (vehicle position estimation unit) that estimates the position of the vehicle after a specified time from the current time and outputs the estimated position; a deviation calculation unit 202 (yaw angle deviation calculation unit) that calculates the deviation between the actual yaw angle of the vehicle and the target yaw angle corresponding to the target path, that is, the yaw angle deviation, based on the target path and the estimated position; a deviation calculation unit 202 (lateral deviation calculation unit) that calculates the deviation between the actual lateral position of the vehicle and the target lateral position corresponding to the target path, that is, the lateral deviation, based on the target path and the estimated position; a target steering angle calculation unit 207 that calculates the target steering angle based on the target curvature, yaw angle deviation and lateral deviation based on the target path; and an EPS 13 (control unit) that controls the steering operation based on the target steering angle when causing the vehicle to travel.

[0093] According to this configuration, the path following performance of the vehicle 1 can be improved by calculating the yaw angle deviation and the lateral deviation based on the estimated position of the vehicle a predetermined time from the present time and using them to calculate the target steering angle.

[0094] In this embodiment, the vehicle position estimating unit 201 (vehicle position estimating unit) preferably estimates the vehicle position a predetermined time from the current position based on the vehicle's current position, and the vehicle's moving speed and moving direction, and outputs the estimated position.

[0095] According to this configuration, specifically, the position of the vehicle 1 a predetermined time from the present can be estimated based on the current position of the vehicle 1 and the moving speed and moving direction of the vehicle.

[0096] In addition, this embodiment preferably calculates the current position of the vehicle by considering the steering response delay matching time of the vehicle's own vehicle position estimation unit in advance. The longer the steering response delay matching time, the smaller the value used by the own vehicle position estimation unit 201 (vehicle position estimation unit) as the prescribed time.

[0097] According to this configuration, a smaller value is used as the predetermined time as the steering response delay matching time used for estimating the position of the vehicle 1 increases. This allows a more appropriate value to be used as the predetermined time, thereby further improving the path following performance of the vehicle 1 .

[0098] In addition, in the present embodiment, it is preferable that the host vehicle position estimating unit 201 (vehicle position estimating unit) uses the target vehicle speed as the moving speed.

[0099] According to this configuration, when the vehicle position estimation unit 201 uses the target vehicle speed as the moving speed, the target vehicle speed is more stable than the actual vehicle speed, and thus the position estimation result of the vehicle 1 can be made more stable.

[0100] Furthermore, the effects brought about by the dependent items and implementation methods of the technical solutions are additional effects different from the effects brought about by the independent items of the technical solutions.

[0101] Description of Reference Signs

[0102] 1…Vehicle, 10…Operation input unit, 11…Monitoring device, 12…Display device, 13…EPS, 14…ECU, 100…Vehicle control system, 201…Vehicle position estimation unit, 202…Deviation calculation unit, 203…Multiplication unit, 204…Multiplication unit, 205…Addition unit, 206…Addition and subtraction unit, 207…Target steering angle calculation unit, 208…Filtering processing unit, 209…Protection processing unit.

Claims

1. A vehicle control device for causing a vehicle to travel along a target path, comprising: a vehicle position estimating unit that estimates the position of the vehicle after a predetermined time from the present time and outputs the estimated position; a yaw angle deviation calculation unit for calculating, based on the target path and the estimated position, a yaw angle deviation, which is a deviation between an actual yaw angle of the vehicle and a target yaw angle corresponding to the target path; a lateral deviation calculation unit for calculating, based on the target path and the estimated position, a lateral deviation, which is a deviation between the actual lateral position of the vehicle and a target lateral position corresponding to the target path; a target steering angle calculation unit that calculates a target steering angle based on a target curvature based on the target path, the yaw angle deviation, and the lateral deviation; and The control unit controls steering based on the target steering angle when the vehicle is driven.

2. The vehicle control device according to claim 1, wherein: The vehicle position estimating unit estimates the position of the vehicle after the predetermined time from the current time based on the current position of the vehicle and the moving speed and moving direction of the vehicle, and outputs the estimated position.

3. The vehicle control device according to claim 2, wherein: The current position of the vehicle is calculated by taking into account the steering response delay matching time of the vehicle's own vehicle position estimation unit in advance, The vehicle position estimating unit uses a smaller value as the predetermined time as the steering response delay matching time increases.

4. The vehicle control device according to claim 2, wherein: The vehicle position estimating unit uses a target vehicle speed as the moving speed.

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