Vehicle movement control device and vehicle movement control method

Abstract

Provided is a vehicle movement control device that can suppress deterioration of ride quality when a vehicle is turning. The present invention comprises an information acquisition unit that acquires information about a curve in front of a vehicle, a turning control planning unit that, on the basis of the information about the curve, plans turning control that is to control the posture of the vehicle when the vehicle is traveling through the curve, and a notification control planning unit that plans notification control that is to control the posture of the vehicle before execution of the turning control and notify a rider of the vehicle of execution of the turning control in advance. The turning control is planned to succeed the notification control, and the notification control planning unit plans the notification control such that a peak in the rate of change over time in a physical quantity related to the posture of the vehicle is between the start time of the notification control and the start time of the turning control.

Description

Vehicle motion control device and vehicle motion control method

[0001] The present invention relates to a vehicle motion control device and a vehicle motion control method.

[0002] Patent Document 1 is known as a technology for assisting a vehicle in turning. The abstract of the document states, "In a vehicle control device 1, a curvature detection unit 36 ​​detects the curvature of the curve ahead of the vehicle. A target roll angle acquisition unit 26 acquires a target roll angle of the vehicle. A target vehicle speed calculation unit 28 calculates a target vehicle speed for the vehicle when entering the curve based on the curvature and the target roll angle. A braking force generation unit 32 generates a braking force on the vehicle so as to decelerate the vehicle to the target vehicle speed when entering the curve."

[0003] Japanese Patent Application Laid-Open No. 2023-5658

[0004] However, the technology in this document does not allow the occupant to know in advance the changes in the pitch angle and roll angle of the vehicle that occur when the vehicle is turning, and therefore the occupant cannot assume a posture that is prepared for the changes in the pitch angle and roll angle of the vehicle that occur when the vehicle is turning, resulting in a problem of a deterioration in ride comfort when the vehicle is turning.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a vehicle motion control device and a vehicle motion control method that can suppress deterioration of ride comfort when a vehicle is cornering.

[0006] In order to solve the above problems, for example, the configurations described in the claims are adopted. The present application includes a plurality of means for solving the above problems, and for example, a vehicle motion control device of the present invention includes an information acquisition unit that acquires information about a curved section ahead of a vehicle, a turning control planning unit that plans turning control to control the attitude of the vehicle when the vehicle travels on the curved section based on the information about the curved section, and a notification control planning unit that controls the attitude of the vehicle before executing the turning control and plans notification control to notify an occupant of the vehicle in advance of the execution of the turning control, wherein the turning control is planned to be continuous with the notification control, and the notification control planning unit plans the notification control so that a time rate of change of a physical quantity related to the attitude of the vehicle occurs at a peak between a start time of the notification control and a start time of the turning control.

[0007] Also, for example, the vehicle motion control method of the present invention includes an information acquisition step of acquiring information about a curved section, a turning control planning step of planning turning control based on the information about the curved section to control the attitude of the vehicle when the vehicle travels on the curved section, and a notification control planning step of planning notification control to control the attitude of the vehicle before the turning control is executed and to notify occupants of the vehicle in advance that the turning control will be executed, wherein the turning control is planned to be continuous with the notification control, and in the notification control planning step, the notification control is planned so that the peak of the time rate of change of a physical quantity related to the attitude of the vehicle occurs between the start time of the notification control and the start time of the turning control.

[0008] According to the present invention, it is possible to provide a vehicle motion control device and a vehicle motion control method that can suppress deterioration of ride comfort when a vehicle is cornering. Problems, configurations, and effects other than those described above will become clear from the description of the following embodiments.

[0009] 1 is a plan view showing an example of the configuration of a vehicle according to a first embodiment. FIG. 2 is a configuration diagram showing the arrangement of main components and functions of a vehicle motion control system according to the first embodiment. FIG. 3 is a diagram showing a travel path of a vehicle used to explain the operation. FIG. 4 is a diagram showing the time change of basic vehicle behavior without the control of the present invention. FIG. 5 is a diagram showing the operation of a vehicle motion control device. FIG. 6 is a diagram showing vehicle behavior when pitch angle control is performed. FIG. 7 is a diagram showing a specific example of the time change of a target pitch angle. FIG. 8 is a diagram showing an example of the relationship between the pitching moment and the distribution of driving force to the front and rear wheels. FIG. 9 is a flowchart explaining the mechanism by which a passenger is shaken during a turn, resulting in a deterioration in ride comfort. FIG. 10 is a flowchart explaining the mechanism by which a deterioration in ride comfort during a turn is suppressed according to the present invention. FIG. 11 is a diagram explaining control of pitch angle and roll angle. FIG. 12 is a diagram showing an example of setting a small peak magnitude of the time rate of change of the pitch angle. FIG. 13 is a diagram showing an example of setting a large peak magnitude of the time rate of change of the pitch angle. FIG. 14 is a diagram explaining setting a time width of a convex shape including a peak in the time rate of change of the pitch angle. FIG. 15 is a diagram showing a case where attitude control of a roll angle is performed based on vehicle behavior before the start of attitude control. FIG. 16 is a diagram showing an example in which there are two peaks in the time rate of change of the pitch angle. FIG. 10 is a configuration diagram showing the layout of main components and functions of a vehicle motion control system according to a second embodiment.

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle motion control device according to the present invention will now be described with reference to the accompanying drawings.

[0011] 1 is a plan view showing an example of the configuration of a vehicle equipped with a vehicle motion control device of this embodiment. Vehicle 1 is a passenger car that carries occupants and travels on a road, and is, for example, a type having dimensions of 4.8 meters in the longitudinal direction (x-axis direction in FIG. 1), 1.8 meters in the lateral direction (y-axis direction in FIG. 1), and 1.7 meters in height (z-axis direction in FIG. 1), and having four wheels 8FL, 8FR, 8RL, and 8RR.

[0012] FIG. 1 shows a schematic diagram of the onboard equipment of the vehicle 1. The vehicle motion control device 2, vehicle state sensor 3, and advanced driver assistance system ECU 12A are electronic devices that perform necessary calculations based on information from connected sensors and an in-vehicle network 9 and output the calculation results to the in-vehicle network 9. The accelerator pedal device 4, brake pedal device 5P, and steering device 6A are devices that detect driver operation and are installed at the driver's seat. They output the detected information to the in-vehicle network 9. The front e-axle 7F and rear e-axle 7R are actuators (wheel drive units) that drive the vehicle 1. These are integrated with an inverter, a motor, a reduction gear, and a differential, and generate torque that rotates the axles from the torque generated by the motor. The motor, which serves as a driving force source, can generate driving force and braking force for the vehicle 1. The steering angle control unit, which steers the wheels of the vehicle 1, is equipped with a steering rack actuator 6B, which can steer the front wheels left and right. Among the above-mentioned onboard devices, those that need to exchange information with other devices via communication are connected to an in-vehicle network 9, allowing each to send and receive information. Only the onboard devices of the vehicle 1 shown in Fig. 1 that are necessary for explaining the operation of this embodiment are shown, and other devices are not shown. Furthermore, even for the devices shown, power lines and other components that are not necessary for explaining the operation of this embodiment are not shown.

[0013] FIG. 2 shows the layout of the main components and functions of the vehicle motion control system. The ADAS system ECU 12A keeps track of the current vehicle position, speed, and other information. It also has map information about the vehicle's surroundings, and uses this information to calculate curvature radius data for the vehicle's future travel, i.e., curvature radius data for roads the vehicle will travel over from the current time to a predetermined time in the future. The curvature radius data is a matrix of elapsed time from the current time and curvature radius. In this embodiment, data for the next 10 seconds is calculated and recorded at 300 ms intervals. The ADAS system ECU 12A transmits this curvature radius data to the in-vehicle network 9. Note that the curvature radius data is an example of information about a curved section ahead of the vehicle. While the following description will use curvature radius data, it is not limited to this.

[0014] The vehicle state sensor 3 acquires current vehicle motion information, such as longitudinal acceleration, lateral acceleration, yaw rate, pitch angle, and roll angle, using internal sensors, and transmits this information as vehicle motion information to the in-vehicle network 9 after performing necessary noise removal processing. The accelerator pedal device 4 detects the amount of pedal depression and transmits this information as accelerator opening to the in-vehicle network 9. The brake pedal device 5P detects the brake pedal depression force and transmits this information as brake depression force to the in-vehicle network 9. The steering wheel device 6A detects the steering wheel rotation position and transmits this information as steering wheel angle to the in-vehicle network 9.

[0015] The vehicle motion control device 2 is roughly composed of a vehicle attitude planning unit 2A and a vehicle motion control unit 2B.

[0016] The vehicle attitude planning unit 2A plans attitude control to suppress deterioration of ride comfort. In this embodiment, the attitude control to suppress deterioration of ride comfort involves controlling the pitch angle. The attitude control start determination unit 2A1 in the vehicle attitude planning unit 2A acquires radius of curvature data and determines, based on the radius of curvature data, whether the vehicle will enter a cornering motion after the current time. In this embodiment, the attitude control start determination unit 2A1 functions as an information acquisition unit that acquires the radius of curvature data, but a separate information acquisition unit may be provided. The lateral acceleration calculation unit 2A2 calculates the lateral acceleration (hereinafter abbreviated as "lateral acceleration") generated in the vehicle 1 based on the radius of curvature data and the vehicle speed. The estimated pitch angle calculation unit 2A3 (estimated physical quantity calculation unit) calculates the pitch angle generated in the vehicle 1 as an estimated pitch angle based on the lateral acceleration generated in the vehicle 1. The target pitch angle planning unit 2A4 (target physical quantity planning unit) plans a target physical quantity so that the target physical quantity, which represents a physical quantity to be realized by the vehicle 1, changes before the estimated physical quantity. When the attitude control start determination unit 2A1 determines that attitude control should be started, the vehicle attitude planning unit 2A outputs the target pitch angle planned by the target pitch angle planning unit 2A4 to the vehicle motion control unit 2B.

[0017] The vehicle motion control unit 2B calculates output commands to the actuators that drive the vehicle 1. The vehicle motion control unit 2B receives the aforementioned curvature radius data, vehicle motion information, accelerator opening, brake pedal force, and steering angle information from the in-vehicle network 9, and calculates a basic driving force and a basic steering amount from these. Next, the vehicle motion control unit 2B calculates the pitching moment required to control the vehicle 1 to the target pitch angle for posture control calculated by the vehicle attitude planning unit 2A. It calculates the front and rear wheel driving force distribution required to generate the calculated pitching moment and the steering amount required to correct the vehicle behavior that is disturbed by the distribution change. These results are then added to the basic driving force and basic steering amount to calculate and output a front wheel driving force command to the front e-axle 7F, a rear wheel driving force command to the rear e-axle 7R, and a steering amount command to the steering rack actuator 6B. The vehicle motion control device 2 performs other corrections necessary for motion control of the vehicle 1 from the output of the vehicle motion control unit 2B, and then transmits the results as a final output to the in-vehicle network 9.

[0018] The front e-axle 7F receives a front wheel drive force command from the in-vehicle network 9, adjusts the motor torque, and drives the front wheels.

[0019] The rear e-axle 7R receives a rear wheel drive force command from the in-vehicle network 9, adjusts the motor torque, and drives the rear wheels.

[0020] The steering rack actuator 6B receives a steering amount command from the in-vehicle network 9, adjusts the motor torque that operates the rack shaft, and determines the steering angle of the front wheels. The operation of the vehicle configured as described above to suppress deterioration of ride comfort will now be described.

[0021] FIG. 3 is a diagram showing an example of a travel route of vehicle 1 used to explain the operation. Assume that vehicle 1 is traveling at a speed of 11 m / s from the illustrated position. The drivable area is between left end 20L and right end 20R of the road ahead. The road curves to the left as vehicle 1 travels. Assume that the radius of curvature of the road centerline is, for example, 30 m. When traveling on this road, vehicle 1 begins steering the front wheels from turning control start position 20S, gradually enters a turn, travels at a constant radius of curvature with a constant amount of steering, then gradually reduces the amount of steering, and returns to straight traveling at turning control end position 20E.

[0022] Figure 4 shows a graph of the basic vehicle behavior over time when traveling along the travel route shown in Figure 3 without the control of the present invention. The graph shows, from top to bottom, steering angle, lateral acceleration, roll angle, and pitch angle. The solid line at 10 seconds represents turning control start time 21S, which passes through turning control start position 20S, and the solid line at 13 seconds represents turning control end time 21E, which passes through turning control end position 20E. First, the steering angle gradually increases from 10 seconds to 11 seconds, remains constant from 11 seconds to 12 seconds, and gradually decreases from 12 seconds to 13 seconds. The lateral acceleration, roll angle, and pitch angle appear with similar waveforms slightly delayed from the steering angle. Here, the pitch angle occurs when the vehicle 1 is subjected to acceleration in the longitudinal direction. In this driving example, no longitudinal acceleration is generated by driving force or the like, but when the wheels generate lateral force when steering to make a turn, the plane of rotation of the wheels has an angle (slip angle) with respect to the direction of travel of the vehicle 1, and the lateral force generated by the wheels also has a component in the longitudinal direction of the vehicle (cornering resistance), so that force generates acceleration in the longitudinal direction, resulting in pitch movement as shown in the figure.

[0023] 5 is an example of a flowchart illustrating the operation of the vehicle motion control device according to this embodiment. In a curvature radius data receiving step S1, the attitude control start determining unit 2A1 receives curvature radius data from the advanced driver assistance system ECU 12A via the in-vehicle network 9. Next, in a curvature radius change extracting step S2, the attitude control start determining unit 2A1 observes changes in the curvature radius from the current time to a predetermined time ahead based on the curvature radius data, and extracts, for example, the presence or absence of a turning section (e.g., a section with a curvature radius of 50 or less), the duration of the turning section (i.e., the time it takes for the vehicle 1 to pass through the turning section), and the time from the current time to entering the turning section. Next, in a posture control start determining step S3, the attitude control start determining unit 2A1 determines whether or not to start attitude control based on the information extracted in the curvature radius change extracting step S2. If the determination is "not to start," the process returns to the curvature radius data receiving step S1. If the determination is "to start," the process proceeds to a lateral acceleration calculation step S4. The attitude control start determination unit 2A1 determines to "start" if, for example, there is a turning section that the vehicle will enter in one second from the current time and the time it will take for the vehicle to pass through the turning section is two seconds or more. The start position of the attitude control is, for example, the attitude control start position 20P shown in Figure 3.

[0024] In the lateral acceleration calculation step S4, the lateral acceleration calculation unit 2A2 calculates the lateral acceleration (lateral acceleration) of the vehicle 1 when traveling at a constant radius of curvature from the current time until a predetermined time from now, based on the radius of curvature data and the vehicle speed. The vehicle speed is preset according to the radius of curvature.

[0025] In estimated pitch angle calculation step S5, estimated pitch angle calculation unit 2A3 calculates the pitch angle predicted to occur when traveling at a constant radius of curvature based on the lateral acceleration as the estimated pitch angle. For example, estimated pitch angle calculation unit 2A3 calculates the centrifugal force acting on vehicle 1 from the lateral acceleration calculated in lateral acceleration calculation step S4, and calculates a cornering force that balances the centrifugal force. Then, based on a previously acquired graph showing the relationship between lateral force and slip angle, it determines a slip angle that can generate the calculated cornering force. The cornering force is equal to lateral force × sin (slip angle × π / 180). Cornering resistance is then calculated from the cornering force and slip angle. Then, pitch angle is calculated from the longitudinal acceleration of vehicle 1 generated by cornering resistance.

[0026] In target pitch angle planning step S6, target pitch angle planning unit 2A4 plans the target pitch angle so that the target pitch angle, which represents the pitch angle to be achieved by vehicle 1, changes prior to the estimated pitch angle. Specifically, target pitch angle planning unit 2A4 plans the target pitch angle so that the peak of the time rate of change of the target physical quantity occurs between the start time (21P) of attitude control and the start time (21S) of turning control.

[0027] In the vehicle motion control step S7, the vehicle motion control section 2B adjusts the command to the actuator to control the vehicle attitude so as to achieve the planned target pitch angle.

[0028] In the turning completion determination step S8, the attitude control start determination unit 2A1 determines whether the turning has been completed based on the curvature radius data. The vehicle motion control device 2 continues the vehicle motion control step S7 until the turning completion determination is made, and returns to the curvature radius data receiving step S1 when the turning completion determination is made.

[0029] Figure 6 shows a graph of the change in vehicle behavior over time when pitch angle control is performed while traveling along the travel route shown in Figure 3. The graph shows, from top to bottom, steering angle, lateral acceleration, roll angle, and pitch angle. Here, the steering angle, lateral acceleration, and roll angle are the same as those shown in Figure 4 when control is not performed, but the pitch angle TPA when pitch angle control is performed begins to change from attitude control start time 21P. For comparison, the pitch angle PA when control is not performed is shown by a dashed line. In this way, attitude control is started at an earlier timing than the start of turning control.

[0030] FIG. 7 shows a specific example of the change in the target pitch angle over time when traveling along the travel route shown in FIG. 3. The vertical axis of the graph, from top to bottom, represents pitch angular velocity and pitch angle. In the upper diagram, the dashed line indicates the pitch angular velocity PAV when no control is performed, and the solid line indicates the pitch angular velocity TPAV when control is performed. In the lower diagram, the dashed line indicates the pitch angle PA when no control is performed, and the solid line indicates the pitch angle TPA when control is performed. Note that the pitch angle PA is an estimated pitch angle calculated based on the lateral acceleration, and the pitch angle TPA is a target pitch angle that changes prior to the pitch angle PA. Specifically, the target pitch angle planning unit 2A4 starts changing the pitch angle TPA, which is the target pitch angle, from the attitude control start time 21P, and plans the pitch angular velocity TPAV, which is the time rate of change of the target pitch angle, to have a peak between the attitude control start time 21P and the turning control start time 21S. This is because the purpose of the attitude control that starts prior to turning control is to notify the occupant that a turn will soon be initiated, and the time change rate is increased to ensure that the occupant is aware of this. Note that it is desirable to set the peak of the pitch angular velocity TPAV in the first half of the period from the attitude control start time 21P to the turning control start time 21S. This ensures time between notifying the occupant in advance that a turn will be initiated and the actual start of turning, allowing the occupant to reliably prepare for turning.

[0031] Regarding a method for controlling the pitch angle by adjusting the driving force, an example of the relationship between the driving force distribution to the front and rear wheels and the pitching moment is shown in Figure 8. In order to control the pitch angle so that a peak occurs in the change in pitch angle, it is necessary to adjust the pitching moment acting on the vehicle. In this embodiment, the pitching moment is generated and the pitch angle is controlled by changing the driving force distribution by utilizing the relationship between the driving force distribution ratio, which is a characteristic of the vehicle, and the magnitude of the pitching moment shown in Figure 8.

[0032] Next, the mechanism by which the riding comfort of the occupant deteriorates due to cornering will be explained with reference to FIG. 9, and then the mechanism by which the deterioration of the riding comfort of the occupant is suppressed by the posture control performed prior to cornering will be explained with reference to FIG. 10.

[0033] Figure 9 is a flowchart showing the mechanism by which a passenger is shaken during cornering, resulting in a deterioration in ride comfort. This corresponds to the case where there is no vehicle attitude control before cornering. First, when the vehicle begins to turn (step S11), lateral acceleration is applied to the passenger (step S12). However, because the passenger is unable to react to the lateral acceleration in time (step S13), the passenger's body is shaken by the lateral acceleration (step S14). As a result, the passenger's ride comfort deteriorates (step S15).

[0034] FIG. 10 is a flowchart showing the mechanism by which the present invention suppresses deterioration of ride comfort during cornering. Here, vehicle attitude control is initiated before cornering (step S20), and in this embodiment, a change in pitch angle is initiated. Next, the occupant senses this change in attitude and prepares for cornering, primarily unconsciously (step S21). The vehicle then begins to turn (step S22), and lateral acceleration is applied to the occupant (step S23). Now that the occupant is prepared for cornering, they smoothly adapt to the lateral acceleration (step S24). This adaptation can be achieved, for example, by tensing the muscles supporting the body and stiffening the body. Next, due to the aforementioned adaptation, the amount of vibration of the occupant's body is reduced (step S25). As a result, the deterioration of the occupant's ride comfort is suppressed (step S26).

[0035] Through the above operations, a vehicle motion control device can be provided that encourages occupants to prepare for cornering by performing pitch angle control earlier than the start of cornering, thereby reducing occupant shaking during cornering and reliably suppressing deterioration of ride comfort.

[0036] FIG. 11 is a diagram illustrating the control of the pitch angle and the roll angle. In this embodiment, an example of controlling the pitch angle as attitude control is shown. However, as shown in FIG. 11, the roll angle, or both the pitch angle and the roll angle, may be controlled. For example, depending on the vehicle's driving conditions, the pitch angle may be very small when turning. In such cases, even if pitch angle control is performed at an early timing, the amount of change is small, making it difficult for the occupant to sense the change in pitch angle. In such cases, the roll angle may be changed as an attitude change to prompt the occupant to prepare for turning. Furthermore, when controlling the roll angle, it is not necessary to stop the pitch angle control, and both the pitch angle and the roll angle may be controlled as shown in FIG. 11.

[0037] FIG. 12 is a diagram showing an example in which the peak magnitude PEAK of the time rate of change of the pitch angle is set small. FIG. 13 is a diagram showing an example in which the peak magnitude PEAK of the time rate of change of the pitch angle is set large. While the example in which the pitch angle is controlled is planned so that it has a peak between the attitude control start time 21P and the turning control start time 21S, the peak magnitude PEAK may be adjusted based on the pitch angle fluctuation amount AMP during straight traveling, which is the vehicle behavior before the attitude control is started, as shown in FIG. 12 . Note that FIG. 12 shows a case in which the pitch angle fluctuation amount AMP during straight traveling, which is the vehicle behavior before the attitude control is started, is small and the peak magnitude PEAK is set small. FIG. 13 shows a case in which the pitch angle fluctuation amount AMP during straight traveling, which is the vehicle behavior before the attitude control is started, is large and the peak magnitude PEAK is set large. For example, the peak magnitude PEAK is set to be at least twice the pitch angle fluctuation amount AMP during straight traveling, which is the vehicle behavior before the attitude control is started.

[0038] FIG. 14 is a diagram illustrating the setting of the time width W of the convex shape including a peak in the time rate of change of the pitch angle. As shown in FIG. 14, the time width W of the convex shape including the peak may be adjusted based on the change period T of the pitch angle when traveling straight, which is the vehicle behavior before the start of attitude control. For example, the time width W of the convex shape including the peak may be set to be equal to or less than half the change period T of the pitch angle when traveling straight, which is the vehicle behavior before the start of attitude control. Furthermore, as shown in FIGS. 12 and 13, the magnitude of the peak PEAK may be set based on the pitch angle fluctuation amount AMP when traveling straight, which is the vehicle behavior before the start of attitude control, and as shown in FIG. 14, the time width W of the convex shape including the peak may be set based on the change period T of the pitch angle when traveling straight, which is the vehicle behavior before the start of attitude control.

[0039] In addition, in FIG. 15, when deceleration is being performed from deceleration start time 21D as the vehicle behavior before the start of attitude control and the pitch angle is already a large value, the roll angle may be controlled in addition to the pitch angle.

[0040] 16 is a diagram showing an example in which there are two peaks in the time rate of change of the pitch angle. As shown in FIG. 16, there may be two peaks (TPAV1, TPAV2) in the time rate of change of the pitch angle. Note that there may be three or more peaks in the time rate of change of the pitch angle.

[0041] The vehicle attitude planning unit 2A described above functions as both a turning control planning unit and a notification control planning unit. The attitude control planned by the vehicle attitude planning unit 2A includes turning control and notification control. Turning control refers to controlling the vehicle attitude when the vehicle travels along a curved section. Notification control refers to controlling the vehicle attitude before the execution of turning control and notifying the vehicle occupants of the execution of turning control in advance. The attitude control plan from the attitude control start time 21P (the start time of notification control) to the turning control start time 21S shown in FIG. 6 corresponds to the notification control plan, and the attitude control plan from the turning control start time 21S to the turning control end time 21E corresponds to the turning control plan. 7, for example, the pitch angle TPA and pitch velocity TPAV from the attitude control start time 21P to the turning control start time 21S correspond to the plan for notification control, and the pitch angle TPA and pitch velocity TPAV from the turning control start time 21S to the turning control end time 21E (not shown) correspond to the plan for turning control. Note that the configuration of this embodiment is just an example, and a configuration may be provided that includes both the turning control planning unit and the notification control planning unit.

[0042] As described above, by adjusting the control target and the size of the peak of the attitude control performed earlier than the start of cornering, as well as the width and number of peaks, it is possible to prevent the attitude control performed earlier than the start of cornering from being overwhelmed by vehicle behavior, etc., thereby providing a vehicle motion control device that can reliably prepare occupants for cornering and suppress vibrations of occupants during cornering, thereby suppressing deterioration of ride comfort.

[0043] FIG. 17 is a plan view showing an example configuration of a vehicle 1B according to a second embodiment. Differences from the vehicle 1 in FIG. 1 will now be described. The vehicle 1B in FIG. 17 does not have a driver's seat and is an autonomous vehicle. For this reason, an autonomous driving system ECU 12B is installed. Furthermore, in-wheel motors 7FL, 7FR, 7RL, and 7RR are installed on each wheel as actuators for driving the vehicle. These motors are the driving force source, so that the vehicle's driving force and braking force can be generated independently for each wheel. Actuators for steering the wheels include a front steering rack actuator 6BF for steering the front wheels and a rear steering rack actuator 6BR for steering the rear wheels, allowing the front and rear wheels to be steered left and right, respectively. Actuators for generating braking force for the vehicle include brake units 5FL, 5FR, 5RL, and 5RR for each wheel. These are electric calipers that can independently control the braking force of each wheel. The actuators that apply force to the wheels in the vertical direction are active suspensions 10FL, 10FR, 10RL, and 10RR mounted on each wheel. These are electromagnetic and generate vertical thrust in response to commands. The actuators that adjust the vehicle's roll rigidity are active anti-roll bars 11F and 11R mounted on the front and rear wheels, respectively. These are electrically operated and can change the amount of twist in response to commands, thereby changing the vehicle's roll rigidity.

[0044] FIG. 18 is a configuration diagram showing the layout of the main components and functions of the vehicle motion control system for vehicle 1B in FIG. 17 . Corresponding to the configuration of vehicle 1B, the system does not have an operating device such as an accelerator pedal device, and an autonomous driving control unit in autonomous driving system ECU 12B generates information necessary for vehicle driving. The vehicle and vehicle motion control system configurations shown in FIGS. 17 and 18 can provide a vehicle motion control device that prompts occupants to prepare for a turn by performing attitude control earlier than the start of a turn in an autonomous vehicle, thereby reducing occupant vibration during a turn and reliably suppressing a deterioration in ride comfort. Furthermore, the vehicle actuators can bias the wheels vertically, change the roll stiffness, and steer the front and rear wheels, allowing for more accurate attitude control. The controllable attitude can be adjusted not only for roll and pitch angles but also for yaw angle and heave. Taking into account the vehicle behavior at that time, a vehicle motion control device can more reliably prompt occupants to prepare for a turn and reduce occupant vibration during a turn, thereby reliably suppressing a deterioration in ride comfort.

[0045] It should be noted that the present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment having all of the described configurations.

[0046] In addition, the control lines and information lines shown are those that are considered necessary for the explanation, and do not necessarily show all the control lines and information lines in the product. In reality, it can be assumed that almost all components are interconnected.

[0047] 1, 1B...vehicle, 2...vehicle motion control device, 2A...vehicle attitude planning unit, 2A1...attitude control start determination unit, 2A2...lateral acceleration calculation unit, 2A3...estimated pitch angle calculation unit (estimated physical quantity calculation unit), 2A4...target pitch angle planning unit (target physical quantity planning unit), 2B...vehicle motion control unit, 6B...steering rack actuator, 7F...front e-axle, 7R...rear e-axle, 12A...advanced driver assistance system ECU, 12B...autonomous driving system ECU, 21E...turning control end time, 21P...attitude control start time (alert control start time), 21S...turning control start time

Claims

1. A vehicle motion control device comprising: an information acquisition unit that acquires information about a curved section in front of the vehicle; a turning control planning unit that plans turning control based on the information about the curved section, the turning control controlling the attitude of the vehicle when the vehicle travels on the curved section; and a notification control planning unit that controls the attitude of the vehicle before the turning control is executed and plans a notification control that notifies occupants of the vehicle in advance of the execution of the turning control, wherein the turning control is planned to follow the notification control, and the notification control planning unit plans the notification control so that a peak of the time rate of change of a physical quantity related to the attitude of the vehicle occurs between the start time of the notification control and the start time of the turning control.

2. A vehicle motion control device as described in claim 1, characterized in that the notification control planning unit sets the magnitude of the peak of the time rate of change of the physical quantity based on the amount of fluctuation of the physical quantity prior to the start time of the notification control.

3. A vehicle motion control device as described in claim 1, characterized in that the notification control planning unit sets the peak of the time rate of change of the physical quantity in the first half of the period from the start time of the notification control to the start time of the turning control.

4. A vehicle motion control device as described in claim 1, characterized in that the notification control planning unit sets the time width of the convex shape including the peak of the time rate of change of the physical quantity based on the period of change of the physical quantity prior to the start time of the notification control.

5. A vehicle motion control device as described in claim 1, wherein the physical quantity is at least one of a pitch angle and a roll angle, and the selection of the physical quantity is performed based on the pitch angle and roll angle prior to the start time of the notification control.

6. A vehicle motion control device according to claim 1, characterized in that the time rate of change of said physical quantity has two or more peaks.

7. A vehicle motion control device according to any one of claims 1 to 6, characterized in that it is mounted on an autonomous vehicle capable of automatically driving the vehicle based on information from the outside world and inside the vehicle.

8. A vehicle motion control method comprising: an information acquisition step for acquiring information on a curved section; a turning control planning step for planning turning control based on the information on the curved section, the turning control controlling the attitude of the vehicle when the vehicle travels on the curved section; and a notification control planning step for planning notification control for controlling the attitude of the vehicle before the turning control is executed and notifying occupants of the vehicle in advance of the execution of the turning control, wherein the turning control is planned to be continuous with the notification control, and in the notification control planning step, the notification control is planned so that a peak of the time rate of change of a physical quantity related to the attitude of the vehicle occurs between the start time of the notification control and the start time of the turning control.

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