Driving control system

Abstract

The present invention provides a vehicle control device that can avoid recesses while minimizing discomfort to the occupants. [Solution] The vehicle 2's driving control device includes a vehicle speed detection unit 61 that detects the vehicle's speed, a recess detection unit 62 that detects the position and length of a recess 101 in the road surface 100 in front of the vehicle, a suspension control unit 63 that controls a plurality of suspension devices 4 provided between the vehicle body 3 and a plurality of wheels 4 and capable of changing the distance between the vehicle body and the wheels in the vertical direction, and a determination unit 64 that determines whether the wheels can pass over the recess based on the vehicle speed and the length of the recess. If the determination unit determines that the vehicle can pass over the recess, the suspension control unit contracts the suspension device corresponding to the wheel when the wheel reaches the edge 111 of the recess.

Description

Technical Field

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

Background Art

[0002] In recent years, efforts to provide a sustainable transportation system that takes into account people in vulnerable positions among traffic participants have been intensifying. In order to further improve traffic safety and convenience towards this realization, research and development on autonomous driving technology have been conducted.

[0003] For example, Patent Document 1 discloses a vehicle driving control device that sets a driving route suitable for rough roads. The driving control device recognizes the height distribution of the road surface in front of the vehicle and generates a driving route such that the wheels pass through a position where the rate of change in road surface height along the traveling direction of the vehicle is small. Patent Document 2 discloses a vehicle driving control device that sets a driving route in consideration of puddles on the road surface.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the driving control devices of Patent Documents 1 and 2, since the driving route is changed to avoid obstacles such as unevenness and puddles, there is a possibility that the vehicle occupants may feel discomfort with the behavior of the vehicle.

[0006] In view of the above background, an object of the present invention is to provide a vehicle control device capable of avoiding concave portions while suppressing the discomfort given to the occupants. Thereby, the present invention aims to contribute to the development of a sustainable transportation system. [Means for solving the problem]

[0007] To solve the above problems, one aspect of the present invention provides a driving control device for a vehicle (2), comprising: a vehicle speed detection unit (61) for detecting the vehicle speed of the vehicle; a recess detection unit (62) for detecting the position and length of a recess (101) present in the road surface (100) in front of the vehicle; a suspension control unit (63) for controlling a plurality of suspension devices (4) provided between the vehicle body (3) and a plurality of wheels (4) and capable of changing the distance between the vehicle body and the wheels in the vertical direction; and a determination unit (64) for determining whether the wheels can pass over the recess based on the vehicle speed and the length of the recess, wherein if the determination unit determines that the vehicle can pass over the recess, the suspension control unit contracts the suspension device corresponding to the wheel when the wheel reaches the edge (112) of the recess.

[0008] According to this embodiment, when a wheel reaches a recess, it is pulled upward towards the vehicle body. As a result, the wheel passes over the recess without entering it. Therefore, the vehicle can travel in a straight line without being affected by the recess. In this way, a vehicle control device can be provided that can avoid recesses while suppressing discomfort to the occupants.

[0009] In the above embodiment, the suspension control unit may determine the amount of compression of the suspension device based on the vehicle speed and the length of the recess.

[0010] According to this embodiment, the wheel can reliably pass over the recess. Furthermore, the impact when the wheel makes contact with the road surface after passing over the recess can be reduced.

[0011] In the above embodiment, the suspension control unit may increase the amount of contraction of the suspension device as the length of the recess increases.

[0012] According to this embodiment, the wheel can reliably pass over the recess. By increasing the amount of suspension compression, the amount of upward movement of the wheel is increased. This makes it possible to lengthen the time it takes for the wheel and vehicle body to move downward and for the wheel to make contact with the road surface.

[0013] In the above embodiment, the suspension control unit may increase the amount of compression of the suspension device as the vehicle speed decreases.

[0014] According to this embodiment, the wheels can reliably pass over the recess even at low vehicle speeds.

[0015] In the above embodiment, the vehicle further comprises a driving control unit (65) that controls the drive unit (41) and braking unit (42) of the vehicle, and if the determination unit determines that the wheels cannot pass over the recess, the driving control unit may control at least one of the drive unit and the braking unit to decelerate the vehicle.

[0016] In this embodiment, if it is determined that the wheels cannot clear the recess even when the suspension is compressed, the vehicle is decelerated. This reduces the impact when the wheels collide with the bottom or edge of the recess.

[0017] In the above embodiment, the system further includes a notification unit that controls a notification device (69) that notifies the occupants of the vehicle, and if the determination unit determines that the vehicle cannot pass over the recess, the notification unit may issue a notification.

[0018] According to this embodiment, the occupants can prepare for the wheels to collide with the recess.

[0019] In the above embodiment, the recess detection unit may detect the recess based on a signal from an optical sensor provided in the vehicle, or it may detect the recess based on information from a database in which the position and shape of the recess are recorded.

[0020] According to this aspect, the travel control device can detect the position and size of the recess.

Advantages of the Invention

[0021] According to the above configuration, it is possible to provide a driving training device, a driving training method, and a program that can improve training efficiency.

Brief Description of the Drawings

[0022] [Figure 1] Explanatory drawing showing the configuration of a vehicle [Figure 2] Cross-sectional view of a suspension device [Figure 3] Functional block diagram showing the functional configuration of a travel control device [Figure 4] Explanatory drawing of a vehicle and a road surface as seen from above [Figure 5] Explanatory drawing showing a method for detecting a recess by LIDAR [Figure 6] An example of a map showing the relationship between vehicle speed, the length of a recess, and a target contraction amount [Figure 7] Flowchart of driving support control [Figure 8] Flowchart of suspension control [Figure 9] Explanatory drawing showing the behavior of a vehicle by suspension control

Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments of a travel control device for a vehicle according to the present invention will be described with reference to the drawings.

[0024] As shown in FIG. 1, a travel control device 1 is provided in a vehicle 2 and controls the travel of the vehicle 2. The vehicle 2 is a four-wheel automobile. The vehicle 2 includes a vehicle body 3, a plurality of suspension devices 4 supported by the vehicle body 3, and a plurality of wheels 5 supported by each of the plurality of suspension devices 4. The sets of suspension devices 4 and wheels 5 are provided at the front right, front left, rear right, and rear left of the vehicle body 3.

[0025] Each suspension device 4 includes a suspension arm 7 rotatably supported by the vehicle body 3, a knuckle 8 provided on the suspension arm 7 for rotatably supporting a wheel 5, and an actuator 9 interposed between the vehicle body 3 and the suspension arm 7. In other embodiments, the actuator 9 may be interposed between the vehicle body 3 and the knuckle 8. Each suspension device 4 is provided between the vehicle body 3 and a plurality of wheels 5, and the distance between the vehicle body 3 and the corresponding wheel 5 in the vertical direction can be changed.

[0026] The actuator 9 is controlled to extend and retract by the travel control device 1, and provides thrust to the vehicle body 3 and suspension arm 7, causing them to move relative to each other. The actuator 9 may be an electromagnetic damper that extends and retracts by the drive of an electric motor, a hydraulic cylinder in which hydraulic pressure is supplied to each chamber of a hydraulic cylinder by an electric pump, or an air spring in which compressed air is supplied to each chamber of an air cylinder by an electric pump. In this embodiment, an example in which an electromagnetic damper is applied to the actuator 9 is shown. The actuator 9, which is an electromagnetic damper, provides thrust to the vehicle body 3 and suspension arm 7, causing them to move relative to each other. In addition, the actuator 9 dampens the relative movement of the vehicle body 3 and suspension arm 7 by providing damping force to the vehicle body 3 and suspension arm 7.

[0027] As shown in Figure 2, the actuator 9 has a cylindrical outer cylinder 12 and a cylindrical inner cylinder 13 with one end inserted into the outer cylinder 12. The inner cylinder 13 is arranged coaxially with the outer cylinder 12 and is displaceable axially relative to the outer cylinder 12. The relative displacement range of the outer cylinder 12 and the inner cylinder 13 along the axial direction is restricted to a predetermined range, and relative rotation about the axis is restricted. A screw shaft 14 is arranged coaxially with the outer cylinder 12. The screw shaft 14 is rotatably supported by the outer cylinder 12 via a bearing 15 at the end opposite the inner cylinder 13. A screw groove for receiving a plurality of balls 16 is formed helically on the outer surface of the screw shaft 14. A nut 17 that screws onto the screw shaft 14 is connected to the end of the inner cylinder 13 inserted into the outer cylinder 12 via the balls 16. The end of the screw shaft 14 on the inner cylinder 13 side passes through the nut 17 and is located inside the inner cylinder 13. The screw shaft 14, ball 16, and nut 17 constitute a ball screw 18.

[0028] The outer circumference of the outer cylinder 12 supports the housing 21 of the electric motor 20. The output shaft 22 of the electric motor 20 is arranged parallel to the screw shaft 14. The electric motor 20 may be any known type of motor, for example, a three-phase brushless motor. A first pulley 24 is coupled to the end of the screw shaft 14 opposite to the inner cylinder 13, and a second pulley 25 is coupled to the output shaft 22 of the electric motor 20. An endless belt 26 is stretched between the first pulley 24 and the second pulley 25. A passage is formed in the outer cylinder 12 through which the belt 26 can pass.

[0029] A disc-shaped first spring seat 28 projecting radially outward is provided on the outer circumference of the outer cylinder 12, and a disc-shaped second spring seat 29 projecting radially outward is provided on the outer circumference of the inner cylinder 13. A compression coil spring 30 is interposed between the first spring seat 28 and the second spring seat 29. The actuator 9 is biased in the extension direction by the compression coil spring 30.

[0030] An outer cylinder mounting portion 31 is provided at the end of the outer cylinder 12 opposite to the inner cylinder 13. An inner cylinder mounting portion 32 is provided at the end of the inner cylinder 13 opposite to the outer cylinder 12. In this embodiment, the outer cylinder mounting portion 31 is connected to the suspension arm 7, and the inner cylinder mounting portion 32 is connected to the vehicle body 3. In other embodiments, the outer cylinder mounting portion 31 may be connected to the vehicle body 3, and the inner cylinder mounting portion 32 may be connected to the suspension arm 7.

[0031] When the outer cylinder 12 and inner cylinder 13 are displaced relative to each other in the axial direction, the nut 17 is displaced relative to the screw shaft 14 in the axial direction, causing the screw shaft 14 to rotate. The rotation of the screw shaft 14 is transmitted to the output shaft 22 of the electric motor 20 via the first pulley 24, belt 26, and second pulley 25, causing the electric motor 20 to rotate. Similarly, when the electric motor 20 rotates, the outer cylinder 12 and inner cylinder 13 are displaced relative to each other in the axial direction. In this way, the relative axial displacement of the outer cylinder 12 and inner cylinder 13, i.e., the extension and contraction of the actuator 9, is linked to the rotation of the electric motor 20. When the electric motor 20 rotates due to the extension and contraction of the actuator 9, an induced electromotive force is generated, and a rotational resistance corresponding to the induced electromotive force is generated, generating a damping force against the extension and contraction of the actuator 9. Also, when the electric motor 20 rotates by receiving power from an external source, the actuator 9 generates thrust in the extension and contraction directions, causing it to extend and contract. The thrust and damping forces generated by the actuator 9 are controlled by the power supplied to the electric motor 20. As shown in Figure 1, the actuator 9 has a stroke sensor 33 that measures the stroke length (position) of the actuator 9.

[0032] As shown in Figure 3, the vehicle 2 has a drive unit 41 that provides driving force to each wheel 5, a braking unit 42 that provides braking force to each wheel 5, and a steering unit 43 that steers the front left and right wheels 5. The drive unit 41 may be at least one of an internal combustion engine and an electric motor. The braking unit 42 may be a disc brake. The steering unit 43 may be a rack and pinion type steering unit.

[0033] Vehicle 2 has a vehicle speed sensor 51 for detecting vehicle speed and a LIDAR 52 (light detection and ranging). The vehicle speed sensor 51 is preferably a sensor that detects the rotation speed of the wheels 5. The LIDAR 52 is an optical sensor that emits laser light in front of vehicle 2 to detect obstacles and the shape of the road surface 100 in front of vehicle 2. Vehicle 2 may also have a GNSS receiver 53 for receiving GNSS (Global Navigation Satellite System) signals.

[0034] The travel control device 1 has a computer that includes a processor such as an MPU (microprocessor) or CPU, and memory such as ROM or RAM. The travel control device 1 realizes various applications by executing calculations according to a program using the processor. The travel control device 1 may be configured as a single piece of hardware, or as a unit consisting of multiple pieces of hardware. Furthermore, at least a part of each functional part of the travel control device 1 may be realized by hardware such as an LSI, ASIC, or FPGA, or by a combination of software and hardware. The program is stored in non-volatile memory such as an HDD or flash memory. The travel control device 1 includes a power module for supplying power to the electric motor 20 and drive unit 41 of the actuator 9.

[0035] The driving control device 1 is connected to the suspension system 4, drive system 41, braking system 42, steering system 43, vehicle speed sensor 51, LIDAR 52, and GNSS receiver 53. The driving control device 1 controls the suspension system 4, drive system 41, braking system 42, and steering system 43.

[0036] The driving control device 1 has the following functional components: a vehicle speed detection unit 61, a recess detection unit 62, a suspension control unit 63, a determination unit 64, a driving control unit 65, a notification unit 66, and a vehicle position detection unit 67.

[0037] The vehicle speed detection unit 61 detects the vehicle speed based on the signal from the vehicle speed sensor 51. In other embodiments, the vehicle speed detection unit 61 may acquire the position of the vehicle 2 at each point in time and acquire the vehicle speed based on the position of the vehicle 2 at each point in time. The position of the vehicle 2 may be detected by the vehicle position detection unit 67 based on the GNSS signal received by the GNSS receiver 53.

[0038] The recess detection unit 62 detects the position and length L of a recess 101 present in the road surface 100 in front of the vehicle 2. The recess 101 includes a pothole. A pothole is a circular depression formed in the asphalt pavement.

[0039] As shown in Figures 4 and 5, the LIDAR 52 irradiates a laser toward the road surface 100 and detects the surface shape of the road surface 100, that is, the height of each position on the road surface 100, based on the scattered light. The LIDAR 52 scans the surface of the road surface 100 by irradiating a laser at predetermined rotation angles θ. Based on the surface shape of the road surface 100 acquired by the LIDAR 52, the recess detection unit 62 determines that the part with a continuous height is the reference surface 104 and that the part with a lower height than the reference surface 104 is the recess 101.

[0040] The recess detection unit 62 may detect the position and length L of the recess 101 based on the signal from the LIDAR 52. Here, the length L of the recess 101 refers to the length L along the direction of extension of the lane 105. The width of the recess 101 refers to the length along the width direction of the lane 105. The recess detection unit 62 may obtain the position of the proximal edge 111, which is the edge of the recess 101 closer to the vehicle 2, and the distal edge 112, which is the edge of the recess 101 further from the vehicle 2, in the portion that overlaps with the predicted trajectory of the left wheel 5 of the vehicle 2 (left predicted trajectory 107) and the predicted trajectory of the right wheel 5 (right predicted trajectory 108). The recess detection unit 62 may then use the distance between the proximal edge 111 and the distal edge 112 as the length L of the recess 101. The position of the proximal edge 111 may be represented by the distance Z1 along the lane 105 from the position of the LIDAR 52. Furthermore, the position of the distal edge 112 may be expressed as the distance Z2 along the lane 105 from the position of the LIDAR 52. The recess detection unit 62 may set the left predicted trajectory 107 and the right predicted trajectory 108 based on the steering angle of the front wheel 5, the vehicle speed, and the current position of the vehicle 2.

[0041] The determination unit 64 determines whether the wheel 5 can pass over the recess 101 based on the vehicle speed and the length L of the recess 101. The determination unit 64 sets a determination value based on the vehicle speed, and if the length L of the recess 101 is less than or equal to the determination value, it is preferable to determine that the wheel 5 can pass over the recess 101. The relationship between the vehicle speed and the determination value is preferably predetermined in a map. The determination value should increase as the vehicle speed increases. As the vehicle speed increases, the time required for the wheel 5 to pass over the recess 101 decreases, and the distance the vehicle body 3 falls during that time decreases. Therefore, as the vehicle speed increases, it becomes easier for the wheel 5 to pass over the recess 101. The determination value is set based on this idea.

[0042] The suspension control unit 63 controls multiple suspension devices 4. When the determination unit 64 determines that the vehicle 2 can pass over the recess 101, the suspension control unit 63 contracts the suspension device 4 corresponding to the wheel 5 when the wheel 5 reaches the edge of the recess 101. As a result, the wheel 5 that has reached the edge of the recess 101 is pulled up towards the vehicle body 3. As a result, even if the part of the vehicle body 3 corresponding to the wheel 5 moves downward due to gravity, the lower end of the wheel 5 is kept above the reference plane 104 of the road surface 100. Consequently, the wheel 5 can pass over the recess 101 without entering the recess 101.

[0043] The suspension control unit 63 determines the target contraction amount ST of the suspension device 4, i.e., the target contraction amount ST of the actuator 9, based on the vehicle speed and the length L of the recess 101, and contracts the actuator 9 corresponding to the wheel 5 that has reached the proximal edge 111 of the recess 101 by the target contraction amount ST. The suspension control unit 63 should increase the target contraction amount ST of the actuator 9 as the vehicle speed decreases. Also, the suspension control unit 63 should increase the target contraction amount ST of the actuator 9 as the length L of the recess 101 increases. The relationship between the vehicle speed, the length L of the recess 101, and the target contraction amount ST of the actuator 9 should be predetermined in a map. Figure 6 is an example of such a map.

[0044] The suspension control unit 63 calculates a target current value to be supplied to the electric motor 20 according to the target contraction amount ST, and supplies the target current value to the electric motor 20. The relationship between the target contraction amount ST and the target current value should be obtained in advance through experiments or other means and defined in a map. The relationship between the target contraction amount ST and the target current value should be set considering the state in which the wheels 5 are separated from the road surface 100.

[0045] The driving control unit 65 controls the drive unit 41 and the braking unit 42. If the determination unit 64 determines that the wheels 5 cannot pass over the recess 101, the driving control unit 65 controls at least one of the drive unit 41 and the braking unit 42 to decelerate the vehicle 2. The driving control unit 65 may reduce the output of the drive unit 41 to decelerate the vehicle 2. The driving control unit 65 may also apply engine braking if the drive unit 41 is an internal combustion engine. The driving control unit 65 may also apply regenerative braking if the drive unit 41 is an electric motor. The driving control unit 65 may also increase the braking force of the braking unit 42 to decelerate the vehicle 2.

[0046] The notification unit 66 provides notification to the occupants of vehicle 2. The notification unit 66 may control a notification device 69 connected to the driving control device 1 to provide notification to the occupants by image, sound, or vibration. The notification device 69 may be an HMI (Human Machine Interface) such as a display, speaker, or vibrator.

[0047] The driving control device 1 performs driving assistance control based on the flowchart in Figure 7. The driving control device 1 repeatedly performs driving assistance control at predetermined time intervals. First, the driving control device 1 detects a recess 101 on the left predicted trajectory 107 or the right predicted trajectory 108 based on the shape of the road surface 100 acquired from the LIDAR 52 (S1). Next, the driving control device 1 determines whether or not a recess 101 exists on the left predicted trajectory 107 or the right predicted trajectory 108 (S2). If no recess 101 exists on either the left predicted trajectory 107 or the right predicted trajectory 108 (the result of the determination in S2 is No), the driving control device 1 repeats the driving assistance control from step S1.

[0048] If a recess 101 exists on the left predicted trajectory 107 or the right predicted trajectory 108 (the result of the determination in S2 is Yes), the driving control device 1 obtains the position of the proximal edge 111, the position of the distal edge 112, and the length L of the recess 101 that exists on the left predicted trajectory 107 or the right predicted trajectory 108 (S3).

[0049] Next, the driving control device 1 determines whether the wheel 5 can pass over the recess 101 based on the vehicle speed and the length L of the recess 101 (S4). The driving control unit 65 sets a determination value based on the vehicle speed and compares the length L of the recess 101 with the determination value. The driving control unit 65 determines that the wheel 5 can pass over the recess 101 if the length L of the recess 101 is less than or equal to the determination value.

[0050] If it is determined that wheel 5 can pass over recess 101 (the result of the determination in S4 is Yes), the driving control device 1 performs suspension control (S5). The driving control device 1 performs suspension control based on the flowchart in Figure 8. In suspension control, the driving control device 1 first determines whether recess 101 is on the left predicted trajectory 107 or the right predicted trajectory 108 (S11). Next, the driving control device 1 calculates the time T1 required for the front wheel 5 corresponding to recess 101 to reach the proximal edge 111 of recess 101, the time T2 required for the front wheel 5 to reach the distal edge 112 of recess 101, the time T3 required for the rear wheel 5 to reach the proximal edge 111 of recess 101, and the time T4 required for the rear wheel 5 to reach the distal edge 112 of recess 101, based on the position of the proximal edge 111 of recess 101 and the vehicle speed (S12). Here, the position of wheel 5 is directly below the center of rotation, that is, the center in the front-rear direction. The driving control device 1 then starts measuring time (S13). Time T1 may be shortened by a predetermined margin so that the front wheel 5 does not enter the recess 101. Similarly, time T3 may be shortened by a predetermined margin so that the front wheel 5 does not enter the recess 101. Also, time T2 may be lengthened by a predetermined margin so that the front wheel 5 does not enter the recess 101. Similarly, time T4 may be lengthened by a predetermined margin so that the rear wheel 5 does not enter the recess 101.

[0051] Next, the driving control device 1 determines the target amount of contraction ST of the actuator 9 of the suspension device 4 based on the length L of the recess 101 and the vehicle speed (S14).

[0052] When the measured time reaches time T1, the driving control device 1 retracts the actuator 9 of the suspension device 4 corresponding to the front wheel 5 on the side where the recess 101 is located in the left-right direction (S15). At this time, the driving control device 1 controls the electric motor 20 so that the actuator 9 retracts by a target amount ST. As a result, the front wheel 5 on the side where the recess 101 is located moves towards the vehicle body 3 in the left-right direction, thus preventing the front wheel 5 from entering the recess 101. At this time, above the recess 101, the wheel 5 and the vehicle body 3 move forward while maintaining their vehicle speed and move downward due to gravity.

[0053] Next, when the measured time reaches time T2, the driving control device 1 extends the actuator 9 of the suspension device 4 corresponding to the front wheel 5 on the side where the recess 101 exists in the left-right direction, in order to return it to its initial state (S16). Here, the initial state refers to the state before the actuator 9 was retracted in step S15. Therefore, in step S16, the driving control device 1 extends the actuator 9 by a target retraction amount ST. As a result of the process in step S16, the front wheel 5 that has passed over the recess 101 makes contact with the reference surface 104 of the road surface 100, and the height of the vehicle body 3 in the part corresponding to the wheel 5 returns to its original state. It is preferable that the extension speed of the actuator 9 in step S16 is sufficiently slower than the retraction speed of the actuator 9 in step S15. This reduces the discomfort that the extension of the actuator 9 may cause to the occupant.

[0054] Next, when the measured time reaches time T3, the driving control device 1 retracts the actuator 9 of the suspension device 4 corresponding to the rear wheel 5 on the side where the recess 101 is located in the left-right direction (S17). At this time, the driving control device 1 controls the electric motor 20 so that the actuator 9 retracts by a target amount ST. As a result, the rear wheel 5 on the side where the recess 101 is located moves towards the vehicle body 3, thus preventing the rear wheel 5 from entering the recess 101. At this time, above the recess 101, the wheel 5 and the vehicle body 3 move forward while maintaining their vehicle speed and move downward due to gravity.

[0055] Next, when the measured time reaches time T4, the driving control device 1 extends the actuator 9 of the suspension device 4 corresponding to the front wheel 5 on the side where the recess 101 exists in the left-right direction, in order to return it to its initial state (S18). Here, the initial state refers to the state before the actuator 9 was retracted in step S17. Therefore, in step S18, the driving control device 1 extends the actuator 9 by a target retraction amount ST. As a result of the process in step S18, the rear wheel 5 that has passed over the recess 101 makes contact with the reference surface 104 of the road surface 100, and the height of the vehicle body 3 in the part corresponding to the wheel 5 returns to its original state. It is preferable that the extension speed of the actuator 9 in step S18 is sufficiently slower than the retraction speed of the actuator 9 in step S17. This reduces the discomfort that the extension of the actuator 9 may cause to the occupant.

[0056] After performing the process in step S18, the driving control device 1 terminates the suspension control.

[0057] If it is determined that the wheel 5 cannot pass over the recess 101 (the result of the determination in S4 is No), the driving control device 1 performs deceleration control and notification control (S6). In deceleration control, the driving control device 1 controls at least one of the drive unit 41 and the brake unit 42 to reduce the vehicle speed. In notification control, the driving control device 1 controls the notification device 69 to notify the occupants that the vehicle 2 is passing over the recess 101.

[0058] According to the above embodiment, as shown in Figure 9, when the wheel 5 reaches the distal edge 112 of the recess 101, it is pulled upward toward the vehicle body 3. As a result, the wheel 5 passes over the recess 101 without entering it. Therefore, the vehicle 2 can travel in a straight line without being affected by the recess 101. In this way, a driving control device 1 can be provided that can avoid the recess 101 while suppressing discomfort to the occupants. Since no steering is required to avoid the recess 101 to the left or right, the driving control device 1 can suppress discomfort to the occupants. Note that in Figure 9, for the sake of explanation, the length L of the recess 101 is shown to be longer than usual.

[0059] Based on the vehicle speed and the length L of the recess 101, the amount of contraction of the suspension device 4, i.e., the amount of contraction of the actuator 9, is determined, so that the wheel 5 can reliably pass over the recess 101. A larger amount of contraction of the suspension device 4 increases the amount of upward movement of the wheel 5. This increases the time it takes for the wheel 5 and the vehicle body 3 to move downward and for the wheel 5 to contact the road surface 100. Furthermore, even at low vehicle speeds, the wheel 5 can reliably pass over the recess 101. In addition, by suppressing the wheel 5 from moving upward from the reference surface 104 of the road surface 100, the impact when the wheel 5, having passed over the recess 101, makes contact with the road surface 100 can be reduced.

[0060] If it is determined that the wheel 5 cannot clear the recess 101 even when the suspension device 4 is compressed, the vehicle 2 is decelerated. This mitigates the impact when the wheel 5 collides with the bottom or edge of the recess 101. In addition, by providing notification when it is determined that the wheel 5 cannot clear the recess 101 even when the suspension is compressed, the occupants can prepare for the wheel 5 to collide with the recess 101.

[0061] This concludes the description of the embodiments, but the present invention is not limited to the above embodiments and can be broadly modified and implemented. For example, the recess detection unit 62 may detect the recess 101 based on information from a database in which the position and shape of the recess 101 are recorded. The database may be included in the driving control device 1 or may be provided outside the vehicle 2. Alternatively, the recess detection unit 62 may detect the recess 101 based on images from an onboard camera that takes pictures of the front of the vehicle.

[0062] In the above embodiment, the actuator 9 corresponding to the wheel 5 is configured to begin contracting when the wheel 5 reaches the proximal edge 111 of the recess 101. However, in other embodiments, the actuator 9 corresponding to the wheel 5 may begin contracting after the wheel 5 reaches the proximal edge 111 but before it reaches the distal edge 112 of the recess 101. That is, as long as the lower end of the wheel 5 is positioned above the reference plane 104 when the wheel 5 reaches the distal edge 112 of the recess 101, the timing of when the actuator 9 begins to contract can be arbitrarily changed.

[0063] In other embodiments, the judgment value may be set to a fixed value regardless of the vehicle speed. Furthermore, the target contraction amount ST may be set to a fixed value regardless of the vehicle speed and the length L of the recess 101.

[0064] If recesses 101 exist on the left predicted trajectory 107 and the right predicted trajectory 108, and both front wheels 5 on the left and right sides reach the recesses 101 simultaneously, the travel control device 1 may determine in step S4 that the wheels 5 cannot pass over the recesses 101. Furthermore, in order to retract the actuator 9 corresponding to a particular wheel 5, it may be required that all actuators 9 corresponding to all other wheels 5 are not in a retracted state.

[0065] In another embodiment, if it is determined in step S4 that the wheel 5 cannot pass over the recess 101 (the determination result in S4 is No), the driving control device 1 may control the steering device 43 to move the vehicle 2 left or right. This allows the wheel 5 to avoid the recess 101 from the left or right. [Explanation of Symbols]

[0066] 1: Driving control device 2: Vehicles 3: Vehicle body 4: Suspension system 5: Wheels 9: Actuator 41: Drive unit 42: Braking device 61: Vehicle speed detection unit 62: Recess detection unit 63: Suspension Control Unit 64: Judgment section 65: Driving control unit 66: Hochi Department 69: Notification device 100: Road surface 101: Recess 107: Left Predicted Trajectory 108: Rightward predicted trajectory 111: Proximal margin 112: Distal margin

Claims

1. A vehicle driving control device, A vehicle speed detection unit for detecting the vehicle speed of the aforementioned vehicle, A recess detection unit for detecting the position and length of a recess present in the road surface in front of the vehicle, A suspension control unit is provided between the vehicle body and multiple wheels and controls multiple suspension devices capable of changing the distance between the vehicle body and the wheels in the vertical direction. It has a determination unit that determines whether the wheel can pass over the recess based on the vehicle speed and the length of the recess, If the determination unit determines that the vehicle can pass over the recess, the suspension control unit retracts the suspension device corresponding to the wheel when the wheel reaches the edge of the recess. The suspension control unit determines the amount of compression of the suspension device based on the vehicle speed and the length of the recess, and the greater the length of the recess, the greater the amount of compression of the suspension device.

2. The driving control device according to claim 1, wherein the suspension control unit increases the amount of compression of the suspension device as the vehicle speed decreases.

3. The vehicle further comprises a driving control unit that controls the drive system and braking system of the aforementioned vehicle. The driving control device according to claim 1, wherein if the determination unit determines that the wheel cannot pass over the recess, the driving control unit controls at least one of the drive unit and the braking unit to decelerate the vehicle.

4. The vehicle further includes a notification unit that controls a notification device that notifies the occupants of the vehicle, The driving control device according to claim 1, wherein the determination unit determines that the vehicle is unable to pass over the recess, and the notification unit provides notification.

5. The driving control device according to claim 1, wherein the recess detection unit detects the recess based on a signal from an optical sensor provided on the vehicle, or detects the recess based on information from a database in which the position and shape of the recess are recorded.

Images