Vehicle control system

Abstract

We provide vehicle control systems that can further improve drivability. [Solution] The vehicle control system 10 includes a posture detection unit 40 that detects the posture of the driver 100 seated in the seat 12, and a controller 60 that controls the steering angle of the vehicle, the controller 60 which controls or corrects the steering angle based on the results detected by the posture detection unit 40.

Description

Technical Field

[0001] This specification discloses a control system for controlling the steering angle of a vehicle.

Background Art

[0002] Patent Document 1 discloses a seat that allows a driver to flexibly change their posture. Specifically, Patent Document 1 discloses a seat support portion that supports the seat portion so as to be rotatable, a seat restoring force generating mechanism that returns the seat portion to its original position, a seat support portion that supports the seat portion so as to be rotatable in the roll direction, a seat restoring force generating mechanism that returns the seat portion to its original position, a seat back support mechanism that supports the seat back so as to be rotatable in the roll direction, and a seat back restoring force generating mechanism that returns the seat back to its original position. According to such a seat, when the vehicle turns, the driver can freely change their posture according to the lateral force generated, so the fatigue of the occupant is reduced and the comfort of the occupant is improved.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when actually performing a steering operation, a driver often changes their posture according to the content of the steering operation they imagine. For example, when a driver intends to make a sharp right turn, they often transition to a posture suitable for a sharp right turn. However, conventionally, such a driver's posture has not been utilized in the steering angle control of the vehicle. As a result, the steering angle control of the vehicle may deviate from the driver's image, and there is a risk that drivability will decrease.

[0005] Therefore, this specification discloses a vehicle control system that can further improve drivability. [Means for solving the problem]

[0006] The vehicle control system disclosed herein is characterized by comprising: an attitude detection unit for detecting the posture of a driver seated in a seat; and a controller for controlling the steering angle of the vehicle, the controller for controlling or correcting the steering angle based on the results detected by the attitude detection unit. [Effects of the Invention]

[0007] According to the technology disclosed herein, the steering angle is controlled or corrected based on the driver's posture, thereby bringing the vehicle steering angle control closer to the driver's driving image and improving drivability. [Brief explanation of the drawing]

[0008] [Figure 1] This is an illustrative diagram showing the configuration of the vehicle's control system. [Figure 2] This diagram shows the process of correcting the target rudder angle based on the detected attitude. [Figure 3] This is an illustrative diagram showing the differences in driving conditions depending on the driver's posture. [Modes for carrying out the invention]

[0009] The configuration of the control system 10 will be described below with reference to the drawings. Figure 1 is a schematic diagram showing the configuration of the control system 10. This control system 10 includes a seat 12, a posture detection unit 40, a front wheel steering actuator 50, a rear wheel steering actuator 52, and a controller 60. The seat 12 is the seat in which the vehicle driver 100 (not shown in Figure 1) sits. The seat 12 is broadly divided into a seat rail 14, a seat cushion 16, a seat back 30, and a headrest 38.

[0010] The seat rail 14 is a skeletal member fixed to the vehicle body. The seat cushion 16 is mounted on the seat rail 14 so as to be slidable in the longitudinal direction of the vehicle. The seat cushion 16 has an SC frame 18 attached to the seat rail 14 and a seat portion 20 that supports the buttocks of the driver 100. The seat portion 20 is pivotable about a pelvic axis 22. For example, the seat portion 20 may be rotatably supported relative to the SC frame 18 by bearings and may also be constantly biased in the direction of its initial state by an elastic body (e.g., a spring, damper, etc.). As shown in Figure 1, the pelvic axis 22 is an axis that extends in a rearward-upward direction so as to pass through the seat portion 20 and the pelvis of the driver 100 seated on the seat 12.

[0011] The seatback 30 supports the back of the driver 100 and has an SB frame 32 and a backrest portion 34. The SB frame 32 is connected to the SC frame 18 via a reclining axis 26 that extends in the vehicle width direction. The SB frame 32, and by extension the entire seatback 30, is capable of swinging (i.e., reclining) around the reclining axis 26. A headrest 38 that supports the driver 100's head is connected to the upper end of the SB frame 32.

[0012] The backrest portion 34 is the part that supports the back of the driver 100 and is rotatable around the backrest axis 36. For example, the backrest portion 34 may be rotatably supported relative to the SB frame 32 by bearings and may also be constantly biased in the initial direction by an elastic body (e.g., a spring, damper, etc.). As shown in Figure 1, the backrest axis 36 is an axis that extends in the longitudinal direction of the vehicle (i.e., in the approximately horizontal direction) so as to pass through the backrest portion 34 and approximately the center of the chest of the driver 100 seated in the seat 12.

[0013] As is clear from the above explanation, the seat 20 can rotate around the pelvic axis 22, and the backrest 34 can rotate around the backrest axis 36. In other words, the driver 100 can change their posture relatively freely while remaining seated in the seat 12. In this example, the steering angle of the vehicle is corrected according to the posture of the driver 100, which will be explained later.

[0014] The posture detection unit 40 detects the posture of the driver 100 seated in the seat 12. For this detection, the posture detection unit 40 has one or more sensors 42. Such sensors 42 may include, for example, sensors that detect the displacement and / or angle of the seat portion 20 and the backrest portion 34, or sensors that detect the pressure acting on the surface (contact surface with the driver 100) of the seat cushion 16 and the seat back 30. Furthermore, the sensors 42 may include an optical sensor (e.g., a CCD camera) that images the driver 100 seated in the seat 12. In any case, the posture detection unit 40 detects the posture of the driver 100 and outputs it to the controller 60.

[0015] The front wheel steering actuator 50 and the rear wheel steering actuator 52 are actuators that change the steering angles of the vehicle's front and rear wheels in response to control commands from the controller 60. In other words, the vehicle in this example is a four-wheel steering vehicle in which the front wheel steering angle and the rear wheel steering angle can be controlled independently. However, the technology in this example is not limited to four-wheel steering vehicles, but may also be applied to vehicles in which only the front wheels or only the rear wheels are controlled.

[0016] The controller 60 calculates the target steering angle of the wheels and outputs control commands to the actuators 50 and 52 according to the calculation result. Physically, the controller 60 is a computer having a processor and memory. In Figure 1, the controller 60 is shown as a single computer, but the controller 60 may be configured by combining multiple physically separated computers.

[0017] Here, usually, the controller 60 calculates the target steering angle of the wheels according to the rotation angle of the steering wheel (i.e., the commanded steering angle) by the driver 100. However, if the target steering angle is calculated only based on the commanded steering angle of the steering wheel, there is a risk of deterioration in drivability. That is, it is difficult to clearly convey the steering content desired by the driver 100 only with the steering wheel, and there may be a deviation between the intention of the driver 100 and the actual steering content. In particular, in the case of a four-wheel steering vehicle where the front wheels and the rear wheels can be controlled independently of each other, it is difficult to accurately transmit the desired steering content of each of the front wheels and the rear wheels only with the steering wheel.

[0018] Therefore, in this example, in addition to the commanded steering angle of the steering wheel, the posture of the driver 100 is also detected, and based on this detected posture, the target steering angle is corrected. The control flow in this case will be described with reference to FIG. 2.

[0019] When the driver 100 wants to turn the vehicle, naturally, the driver 100 operates the steering wheel (S12). The controller 60 detects the steering angle of this steering wheel, that is, the commanded steering angle (S14).

[0020] Also, when the driver 100 wants to turn the vehicle, according to the content of the turn, the driver 100 changes the posture (S10). This is the same as the case of controlling the way of turning using the body in a bicycle or skiing. The driver 100 in the upper left of FIG. 2 is a schematic of the posture when the driver 100 wants to turn with a relatively large slip angle in the right direction (left direction of the paper) as viewed from the driver 100. As is clear from this schematic diagram, in this case, the driver 100 twists the upper body in the turning direction (left direction of the paper). That is, the spine is made into an arc shape convex in the direction opposite to the turning direction (right direction of the paper).

[0021] Thus, when the driver 100 changes his / her posture, the seat cushion 16 and the seat back 30 move by receiving force from the driver 100 (S16). The posture detection unit 40 detects the movement (in the example of FIG. 2, the tilt angle) of the seat cushion 16 and the seat back 30 with the sensor 42 (S18, S20). The detected tilt angle is sent to the controller 60 together with the commanded steering angle.

[0022] Based on the obtained tilt angle (i.e., the parameter representing the posture of the driver 100) and the commanded steering angle, the controller 60 calculates the target steering angles of the front wheels and the rear wheels (S22). Then, the controller 60 outputs commands to the front-wheel steering actuator 50 and the rear-wheel steering actuator 52 so that the calculated target steering angles are achieved. In response to the commands, the actuators 50, 52 are driven, and the front wheels and the rear wheels are steered, thereby realizing the turning travel intended by the driver 100 (S24).

[0023] Here, various forms can be considered as the method for calculating the target steering angle in consideration of the posture of the driver 100. For example, when there is a steering mechanism only for the front wheels (in the case of a two-wheel steering vehicle), the steering angle obtained by adding the commanded steering angle obtained from the steering wheel and the steering angle calculated from the detected posture may be calculated as the target steering angle of the front wheels. Also, when there are steering mechanisms for both the front wheels and the rear wheels (in the case of a four-wheel steering vehicle), the steering angle of the rear wheels is calculated as before, and the steering angle obtained by adding the commanded steering angle obtained from the steering wheel and the steering angle calculated from the detected posture may be calculated as the target steering angle of the front wheels. Thus, by correcting the steering angle of the front wheels according to the posture of the driver 100, it becomes possible to make a turn that matches the driver 100's desire. Also, such a correction instruction for the front wheels is determined from the posture of the driver 100. Therefore, the driver 100 can intuitively correct the steering angle of the front wheels, and the drivability is further improved.

[0024] Alternatively, the target steering angle of the front wheels may be calculated based on the command steering angle obtained from the steering wheel, and the target steering angle of the rear wheels may be calculated based on the steering angle calculated from the detected attitude. More specifically, the target steering angle of the rear wheels may be calculated so that the vehicle performs a yaw motion in the direction of the yaw twist of the driver's rib cage. Figure 3 is an illustrative diagram showing the difference in driving conditions depending on the attitude of the driver 100.

[0025] The left and right ends of Figure 3 show schematic top and rear views of driver 100, respectively. In Figure 3, the hatched areas indicate the waist regions of drivers 100L and 100R. As shown on the left end of Figure 3, consider the case where the yaw twist of driver 100L's rib cage is small, that is, when the shoulder line A1 and waist line A2 of driver 100L are approximately parallel. In this case, the controller 60 sets the target steering angle of the rear wheels to approximately 0. In this case, the vehicle travels along the driving path 110L in the posture of vehicle 130L in Figure 3.

[0026] On the other hand, consider the case where the yaw twist of the driver 100R's rib cage is large, as shown on the far right of Figure 3, that is, when the shoulder line A1 and the hip line A2 of driver 100L intersect. In this case, the curvature of the driving path 110R is the same as the curvature of the driving path 110L. However, the slip angle of vehicle 130R is larger than that of vehicle 130L, and vehicle 130R can obtain cornering force earlier than vehicle 130L. As a result, the vehicle body can be stabilized earlier even when making sharp turns.

[0027] In other words, by changing the target steering angle of the rear wheels according to the driver's posture, different turning conditions can be generated even if the curvature of the driving path 110 is the same, enabling turns that better match the driver's preferences. Furthermore, these instructions for the rear wheel steering angle are determined from the driver's posture. As a result, the driver can intuitively operate the rear wheels. Consequently, the drivability of the driver can be further improved.

[0028] Furthermore, the driver's posture changes not only due to the driver's active actions but also due to forces (inertial force and centrifugal force) generated as the vehicle moves. To distinguish between active posture changes intended by the driver 100 and passive posture changes caused by external forces, the amount of passive posture change may be identified in advance. When the vehicle is actually driven, the target steering angle may be calculated based on a value obtained by subtracting the amount of passive posture change from the amount of posture change of the driver 100. In addition, the degree to which the angle of the seat cushion 16 and the angle of the seat back 30 intervene in steering may be changed. By using such a configuration, the operating sensation can be changed. For example, steering control may be primarily based on the waist, or primarily on the chest and shoulders. Alternatively, steering control may be performed only by the relative movement of the waist and chest. Furthermore, the driver 100 may be allowed to freely select which control method to use.

[0029] Furthermore, the method for detecting the driver's posture 100 may also be changed as appropriate. For example, pressure sensors may be placed at arbitrary positions on the seat 12, and steering intervention may be triggered based on the change in pressure distribution. For example, consider a case where pressure sensors are placed on both shoulders and shoulder blades on the seat 12, and the body is yaw-rotated towards the inside of a turn. In this case, the pressure on the inside of the turn increases, and the pressure on the outside of the turn decreases. When this relative pressure difference occurs, follow-up steering may be triggered, or for those who push to turn the steering wheel, follow-up steering may be triggered when the pressure on the outside of the turn is high.

[0030] Furthermore, pressure sensors or the like can be installed in the seatback 30 to determine the relative force relationship between the lumbar region and the rib cage, and acceleration and deceleration can be controlled such that acceleration occurs when the pressure in the lumbar region is high, and deceleration occurs when the pressure in the rib cage is high. By implementing such control, the rider can maintain a balanced posture so that their head does not sway back and forth during acceleration and deceleration.

[0031] Furthermore, the vehicle's physical characteristics, such as roll stiffness due to the active stabilizer and steering gear ratio, may be changed depending on the driver's posture. For example, if the driver's active driving actions (motivation conveyed through their body) are detected, the vehicle characteristics may be made agile, while if they are relaxed, the vehicle characteristics may be made gentle.

[0032] In any case, by detecting the driver's posture and controlling or correcting the steering angle of the wheels according to the detected posture, the driver's intentions can be more accurately reflected in the steering angle, and the driver can steer more intuitively. As a result, drivability can be further improved. Note that the above-described configurations are all examples, and other configurations may be changed as appropriate as long as the configuration of claim 1 can be achieved. [Explanation of symbols]

[0033] 10 Control system, 12 Seat, 14 Seat rail, 16 Seat cushion, 18 SC frame, 20 Seat section, 22 Pelvic axis, 26 Reclining axis, 30 Seat back, 32 SB frame, 34 Backrest section, 36 Backrest axis, 38 Headrest, 40 Posture detection unit, 42 Sensor, 50 Front wheel steering actuator, 52 Rear wheel steering actuator, 60 Controller, 100 Driver, 110 Driving path.

Claims

[Claim 1] A posture detection unit that detects the posture of the driver seated in the seat, A controller for controlling the steering angle of a vehicle, comprising a controller that controls or corrects the steering angle based on the results detected by the attitude detection unit, A vehicle control system characterized by comprising the following features.

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