Vehicle control method and vehicle control device

Abstract

A vehicle control device (10) comprises a sensor (12) that detects the roll angular velocity of the vehicle body of a vehicle (1), and a controller (18) that, on the basis of the roll angular velocity detected by the sensor (12), causes the vehicle to decelerate by controlling at least one among a driving force source for driving the vehicle and a braking device for braking the vehicle during a period in which the absolute value of the roll angular acceleration of the vehicle body increases and / or causes the vehicle to accelerate by controlling the driving force source during a period in which the absolute value of the roll angular acceleration decreases.

Description

[Technical Field]

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

[0002] The following Patent Document 1 describes a vehicle body attitude control device that sets a target pitch rate according to the magnitude of the roll rate of the vehicle body and generates a pitch moment using actuators provided on each of the four wheels so that the pitch rate of the vehicle body approaches the target pitch rate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-46172 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, in controlling the lateral sway of a vehicle body, it has been common to suppress changes in the roll posture and vertical fluctuations of the vehicle body using hardware that uses support from the vehicle's unsprung structure to the body as control input. Therefore, to suppress changes in the posture of occupants when the vehicle body sways, dedicated hardware for vehicle posture control is required. The present invention aims to suppress changes in the posture of an occupant caused by lateral sway of a vehicle body with a simple structure. [Means for solving the problem]

[0005] A vehicle control method according to one aspect of the present invention detects a roll angular velocity of a vehicle body, and, based on the detected roll angular velocity, decelerates the vehicle during a period in which the absolute value of the roll angular acceleration of the vehicle body increases, and / or accelerates the vehicle during a period in which the absolute value of the roll angular acceleration decreases. [Effects of the Invention]

[0006] According to the present invention, the change in the posture of the occupant caused by the lateral sway of the vehicle body can be suppressed with a simple structure. The objects and advantages of the invention will be realized and attained by means of the elements and combinations set forth in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic configuration diagram of an example of a vehicle control device according to an embodiment; [Figure 2] FIG. 2 is an explanatory diagram of each direction set in a vehicle. [Figure 3] (a) is a graph showing the time change in the lateral acceleration of the lateral transient motion and the positive acceleration added by the acceleration, (b) is a graph showing the time change in the lateral acceleration of the lateral transient motion and the negative acceleration added by the deceleration, and (c) is the experimental result showing the change in the roll attitude angle of the occupant in cases (a) and (b). [Figure 4] (a) is a graph showing the time change in lateral acceleration of lateral transient motion, (b) is a graph showing the time change in deceleration and acceleration applied by braking and driving the vehicle, and (c) is a graph showing the time change in the roll attitude angle of the occupant. [Figure 5] 4 is a diagram illustrating lateral inertial acceleration of an occupant caused by roll of a vehicle body. FIG. [Figure 6] (a) is a graph showing the time variation of roll angular acceleration and roll angular jerk, and (b) is a graph showing the corrected longitudinal acceleration. [Figure 7] 3 is a flowchart of a first example of a vehicle control method according to an embodiment. [Figure 8] (a) is a graph of the change over time in roll angular acceleration and roll angular velocity, and (b) is a graph of the corrected longitudinal acceleration. [Figure 9] 10 is a flowchart of a second example of a vehicle control method according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] (composition) Hereinafter, embodiments will be described with reference to the accompanying drawings. In this specification, "longitudinal acceleration" includes not only the rate of increase in vehicle speed in the forward direction of the vehicle, but also the rate of decrease in that speed (i.e., deceleration). In particular, the sign of acceleration when the vehicle speed increases is positive, and the sign of acceleration when the vehicle speed decreases is negative. Furthermore, "lateral acceleration" is a concept that includes acceleration occurring in one direction in the vehicle width direction (either leftward or rightward relative to the forward direction of the vehicle) and acceleration occurring in the other direction (the other of leftward or rightward). For convenience of explanation, the sign of "lateral acceleration" is defined as positive when heading leftward relative to the forward direction of the vehicle, and negative when heading rightward.

[0009] 1 is a schematic configuration diagram of an example of a vehicle control device according to an embodiment. A vehicle 1 is equipped with a vehicle control device 10 that controls the driving of the vehicle 1. The driving control by the vehicle control device 10 includes autonomous driving control that automatically drives the vehicle 1 without the involvement of a driver based on the driving environment around the vehicle 1, and driving assistance control that assists the driver in driving the vehicle 1 by controlling at least one of driving, braking, and steering of the vehicle 1. The driving assistance control may be, for example, automatic steering, automatic braking, preceding vehicle following control, constant speed driving control, lane keeping control, merging assistance control, etc.

[0010] The vehicle control device 10 includes an object sensor 11, a vehicle sensor 12, a positioning device 13, a map database (map DB) 14, a communication device 15, a navigation device 16, an actuator 17, and a controller 18. The object sensor 11 includes a plurality of different types of object detection sensors mounted on the vehicle 1, such as a laser radar, a millimeter wave radar, a camera, and a LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) that detect objects around the vehicle 1. The vehicle sensors 12 are mounted on the vehicle 1 and detect various pieces of information (vehicle signals) obtained from the vehicle 1. For example, the vehicle sensors 12 include a vehicle speed sensor that detects the vehicle speed of the vehicle 1, a wheel speed sensor that detects the rotational speed of the tires of the vehicle 1, a three-axis acceleration sensor that detects the acceleration and deceleration of the vehicle 1 in three axial directions, a yaw rate sensor that detects the yaw angular velocity (yaw rate) of the vehicle body, and a roll rate sensor that detects the roll angular velocity of the vehicle body. Note that detection also includes estimation. For example, the roll angular velocity of the vehicle body can be estimated by using a sensor that measures the lateral acceleration of the vehicle instead of a roll rate sensor. Specifically, estimation can be achieved by focusing on the proportional relationship between the lateral acceleration and the roll angular velocity. The vehicle sensor 12 includes, for example, an accelerator sensor for detecting the accelerator opening degree of the vehicle, a brake sensor for detecting the brake operation amount by the driver, a steering angle sensor for detecting the steering angle of the steered wheels, and a steering angle θ of the steering wheel. s The steering angle sensor detects the steering angle velocity ω of the steering wheel. s This information can also be obtained from the vehicle sensor 12.

[0011] The positioning device 13 includes a Global Navigation System (GNSS) receiver and receives radio waves from multiple navigation satellites to measure the current position of the vehicle 1. The GNSS receiver may be, for example, a Global Positioning System (GPS) receiver. The positioning device 13 may also be, for example, an inertial navigation system. The map database 14 stores road map data. For example, the map database 14 may store high-precision map data suitable as map information for automated driving. The map database 14 may also store map data for navigation. The communication device 15 performs wireless communication with a communication device outside the vehicle 1. The communication method used by the communication device 15 may be, for example, wireless communication using a public mobile phone network, vehicle-to-vehicle communication, road-to-vehicle communication, or satellite communication.

[0012] The navigation device 16 recognizes the current position of the vehicle using the positioning device 13 and obtains map information for the current position from the map database 14. The navigation device 16 sets a driving route to the destination input by the occupant and provides route guidance to the occupant along this driving route. The navigation device 16 also outputs information about the set driving route to the controller 18. During autonomous driving control, the controller 18 automatically drives the vehicle 1 so that the vehicle travels along the driving route set by the navigation device 16.

[0013] The actuator 17 is a device that performs operations to bring the vehicle 1 into a desired motion state in response to a control signal from the controller 18. The actuator 17 mainly includes a drive system actuator that adjusts the acceleration of the vehicle 1 in the longitudinal direction, and a steering system actuator that adjusts the turning motion of the vehicle 1. If the vehicle 1 is equipped with an engine as a driving source, the drive system actuator may include a throttle valve that adjusts the amount of air supplied to the engine (throttle opening), and a friction brake that adjusts the braking force applied to the wheels of the vehicle 1. If the vehicle 1 is equipped with a motor as a driving source (if it is a hybrid vehicle or an electric vehicle), the drivetrain actuator may include a power adjustment device (such as an inverter and a converter) that adjusts the power supplied to the motor. In this case, the deceleration function of the drivetrain actuator may be achieved by regenerative driving (regenerative braking) instead of or in addition to a friction brake. On the other hand, the steering actuator may include an assist motor that controls the steering torque in an electric power steering system, or a steering motor that controls the steering torque in a steer-by-wire system.

[0014] The controller 18 is an electronic control unit (ECU) that controls the driving of the vehicle 1. The controller 18 includes a processor 18a and peripheral components such as a storage device 18b. The processor 18a may be, for example, a CPU or an MPU. The storage device 18b may include a semiconductor storage device, a magnetic storage device, an optical storage device, etc. The storage device 18b may include a register, a cache memory, a memory such as a ROM and a RAM used as a main memory device, etc. The functions of the controller 18 described below are realized by, for example, the processor 18a executing a computer program stored in the storage device 18b. The controller 18 may be formed of dedicated hardware for executing the information processing described below. For example, the controller 18 may include a functional logic circuit configured in a general-purpose semiconductor integrated circuit. For example, the controller 18 may include a PLD such as an FPGA.

[0015] Next, a method for controlling the vehicle 1 by the vehicle control device 10 of the embodiment will be described. For ease of explanation, the directions and angles of the vehicle 1 used in this specification are defined as shown in FIG. 2. Reference character O indicates an occupant riding in the vehicle 1, and reference character S indicates a vehicle seat in which the occupant O sits. The occupant O may be a driver or a passenger. The vehicle seat S includes at least a seat back Sb and a seat cushion Sc. The "vertical direction," "front-back direction," and "lateral direction" are respectively referred to as the ζ-axis direction, the ξ-axis direction, and the η-axis direction. Furthermore, the angle in which the direction from the ζ-axis toward the η-axis in the ζ-η plane with the trunk of the occupant O as the axis is positive is referred to as the "roll attitude angle Φ," and the angle in which the direction from the ζ-axis toward the ξ-axis in the ζ-ξ plane with the trunk of the occupant O as the axis is positive is referred to as the "pitch attitude angle Ψ."

[0016] The vehicle control device 10 sets the basic longitudinal acceleration Ab to be generated in the vehicle 1 according to the amount of accelerator pedal operation by the driver or the required driving force set by autonomous driving control or driving assistance control. The basic longitudinal acceleration Ab corresponds to a target value of acceleration (a target value according to the required driving force) for realizing intended translational motion of the vehicle 1 according to the driving scene. The vehicle control device 10 changes the pressure load of the occupant O against the seat back Sb of the vehicle seat S by correcting the basic longitudinal acceleration Ab and applying an acceleration that decelerates or accelerates the vehicle 1. This reduces the body sway of the occupant O due to lateral shaking of the vehicle body, improving the comfort of the occupant while riding.

[0017] Generally, the comfort of a passenger O while riding in the vehicle can be improved by reducing the body sway of the passenger O in response to the movement of the vehicle 1. For example, car sickness is thought to be caused by a mismatch between the movement perceived by the kinesthetic organs due to the movement of the passenger's body and head and the recognition of movement by the passenger's vision, etc. (Motion Conflict Theory). To suppress body shaking, it is effective to adjust the relative movement between the body of the occupant O and the seat back Sb. For example, if the pressure load of the occupant O on the seat back Sb is increased, the change in the posture of the occupant O due to the lateral shaking of the vehicle 1 can be suppressed, which is expected to have the effect of reducing car sickness.

[0018] One possible means for suppressing the change in posture of the occupant O by increasing the pressure load of the occupant O on the seat back Sb is to apply a positive acceleration to the vehicle 1 in the longitudinal direction. Figures 3(a) to 3(c) show the simulation results of the maximum amplitude of the roll attitude angle Φ of the occupant O when longitudinal acceleration is applied to a vehicle undergoing lateral transient motion. As shown in Figures 3(a) and 3(b), the maximum amplitude of the roll attitude angle Φ of the occupant O is 1.5 m / s due to a transient motion such as a lane change. 2 While generating a sinusoidal lateral acceleration of ±0.25 [m / s], the acceleration in the longitudinal direction is also set to a threshold value (hereinafter referred to as "threshold acceleration") that is the threshold value for whether or not the occupant O can recognize the vehicle. 2 ] is added. Generally, the lower limit of acceleration that a human can perceive in the front-to-back direction of the body in a static laboratory environment (hereinafter referred to as the "standard sensory threshold") is approximately 0.05 to 0.1 m / s 2However, when exposed to external factors such as vibrations in a vehicle driving environment, the threshold acceleration for whether or not the occupant O can recognize the vehicle is approximately 0.2 to 0.3 m / s. 2 Even if a longitudinal acceleration of this magnitude is applied, it is difficult for the occupant O to recognize it as acceleration or deceleration.

[0019] In contrast, there is a clear difference in the body movement of occupant O, as shown in Figure 3(c), with a negative longitudinal acceleration (-0.25 m / s 2 ]) is added, the positive forward / backward acceleration (0.25 [m / s 2 ]) is added, the roll posture angle Φ of the occupant O is significantly reduced. This effect is thought to be due to an increase or decrease in friction caused by a change in the pressure load of the occupant O against the seat back Sb. This result shows that there is an acceleration range in which the posture change of the occupant O can be reduced by acceleration or deceleration in the longitudinal direction without causing discomfort or inducing car sickness.

[0020] Therefore, it is conceivable to reduce the change in posture of the occupant O by continuously accelerating the vehicle during the lateral transient movement, thereby constantly pressing the occupant's body against the seat back Sb, but adding acceleration in this way would cause a speed change that deviates from the vehicle movement intended by the driver or the vehicle movement intended by autonomous driving control or driving assistance control. Therefore, it is preferable to add a combination of deceleration and acceleration of about the threshold acceleration so as to suppress the change in posture of the occupant and not affect the intended vehicle movement. Figures 4(a) to 4(c) show the simulation results of the maximum amplitude of the roll attitude angle Φ of occupant O when the vehicle 1 performs a predetermined lateral transient movement (lane change) using an inverted pendulum-type occupant model and the roll direction attitude change stiffness of occupant O is increased or decreased by a threshold acceleration (±0.025G) in the longitudinal direction. In this lane change, after a certain time (in this case, 4 seconds), vehicle 1 moves to the adjacent lane (the amount of lateral movement is specified) and returns to straight-ahead driving.The driving intention is set so that the vehicle speed is the same at the initial speed and the end point, and then optimization calculations are performed, and the optimal solution is calculated both with and without adding a threshold acceleration.

[0021] When changing lanes, two transient movements occur in which the direction of lateral acceleration reverses: in the phase in which the vehicle's longitudinal direction is directed toward an adjacent lane (hereinafter referred to as "movement phase I"), and in the phase in which the vehicle's longitudinal direction is returned to its original position (hereinafter referred to as "return phase II"). For each transient movement, it was found that the change in the roll attitude angle Φ of the body of occupant O was minimized when vehicle 1 was decelerated in the section in which the absolute value of acceleration increased, and when vehicle 1 was accelerated in the section in which the absolute value of acceleration decreased. The simulation results showed that the change in roll attitude angle Φ of occupant O was reduced by approximately 17% compared to when no longitudinal acceleration was applied to vehicle 1.

[0022] In the present invention, the effect of suppressing the change in the roll attitude angle Φ of the occupant O due to the addition of such longitudinal acceleration is utilized to suppress the change in the roll attitude angle Φ of the occupant O that accompanies the vehicle motion due to an external disturbance. Vehicle motion due to external disturbances mainly consists of road surface disturbances and aerodynamic disturbances such as crosswinds, and these disturbances cause the vehicle body to move even without driver operation. Although the magnitude of this motion is small, it continues to move while driving, which may impair passenger comfort. The vehicle body movements caused by such disturbances occur in the vertical, longitudinal, and lateral directions, and are applied to the occupants as inertial acceleration. Of these, lateral vehicle body movements, known as lateral vibration, include a component due to the vehicle's planar motion and a component due to the vehicle's roll motion.

[0023] FIG. 5 is an explanatory diagram of the lateral inertial acceleration of an occupant caused by the roll of the vehicle body. The lateral inertial acceleration acting on the occupant is the sum of the lateral inertial acceleration due to the vehicle's planar motion and the lateral inertial acceleration due to the roll (-a Roll ) and the lateral inertial acceleration due to roll (-a Roll) occurs when the vehicle rolls around an imaginary center of rotation Pc, called the roll center of the vehicle, in the case of a small movement at the level of rolling caused by an external disturbance. Therefore, the height h from the roll center Pc to the seating point Ps of the occupant O and the roll angular acceleration of the vehicle (roll angle Φ V The amount multiplied by the second derivative of the vehicle acceleration (-a Roll ) Therefore, if the change in body posture of the occupant O caused by the lateral acceleration due to the rolling motion of the vehicle body can be controlled by using the longitudinal acceleration, it will be possible to reduce the discomfort caused by the lateral shaking that occurs constantly while driving.

[0024] An example of setting the longitudinal acceleration will be described with reference to Figures 6(a) and 6(b). Figure 6(a) is a graph showing the time variation of the roll angular acceleration and roll angular jerk of the roll motion caused by the lateral sway of the vehicle body, and Figure 6(b) is a graph showing the longitudinal acceleration (hereinafter referred to as "corrected longitudinal acceleration Ac") added to suppress the change in the body posture of the occupant O. The roll motion caused by the lateral sway of the vehicle body consists of a first phase I-1, in which the signs of both the roll angular acceleration and the roll angular jerk (the first derivative of the roll angular acceleration) are positive, a second phase I-2, in which the sign of the roll angular acceleration is positive and the sign of the roll angular jerk is negative, a third phase II-1, in which the signs of both the roll angular acceleration and the roll angular jerk are negative, and a fourth phase II-2, in which the sign of the roll angular acceleration is negative and the sign of the roll angular jerk is positive. The absolute value of the roll angular acceleration of the vehicle body increases in the first phase I-1 and the third phase II-1, and decreases in the second phase I-2 and the fourth phase II-2.

[0025] Therefore, by multiplying the roll angular acceleration of the vehicle body by the roll angular jerk, which is the amount of change in the roll angular acceleration, and calculating the sign of the product of the roll angular acceleration and the roll angular jerk, it is possible to determine whether the absolute value of the roll angular acceleration of the vehicle body is increasing (i.e., whether a negative longitudinal acceleration is applied) or whether the absolute value of the roll angular acceleration is decreasing (i.e., whether a positive longitudinal acceleration is applied). Note that, when a sensor capable of directly detecting the roll angular acceleration and the roll angular jerk is available, these physical quantities may be detected directly by the sensor, or the roll angular acceleration and the roll angular jerk may be detected based on the detected value or estimated value of the roll rate sensor of the vehicle sensor 12. For example, the roll angular acceleration may be calculated by differentiating the detected value or estimated value of the roll rate sensor of the vehicle sensor 12, and the roll angular jerk may be calculated by differentiating the roll angular acceleration.

[0026] For example, the controller 18 may set the corrected longitudinal acceleration Ac based on the following equation (1). Ac = -Sgn [roll angular acceleration × roll angular jerk] × |a|…(1) where Sgn[x] is a sign function such that Sgn[x]=+1 when variable x>0, Sgn[x]=0 when variable x=0, and Sgn[x]=-1 when variable x<0, and |a| is a predetermined set acceleration amount. For example, the set acceleration amount |a| is preferably set to a threshold acceleration of approximately 0.02 to 0.03 G. Since the length of time for applying the negative corrective longitudinal acceleration Ac and the length of time for applying the positive corrective longitudinal acceleration Ac are approximately the same, the average speed change is approximately 0, and the intended vehicle motion is not hindered.

[0027] The controller 18 calculates the target longitudinal acceleration At by adding the corrected longitudinal acceleration Ac to the basic longitudinal acceleration Ab. The controller 18 calculates the operation amount of the actuator 17 so that the actual longitudinal acceleration of the vehicle 1 approaches the target longitudinal acceleration At, and controls the actuator 17 based on the operation amount. More specifically, the controller 18 controls the throttle opening, motor output, or friction brake so as to satisfy the target longitudinal acceleration At. In particular, if the vehicle 1 is an electric vehicle, the controller 18 operates the power regulation device to apply a positive torque to the motor when increasing the magnitude of the target longitudinal acceleration At (accelerating the vehicle 1). On the other hand, when decreasing the magnitude of the target longitudinal acceleration At (decelerating the vehicle 1), the controller 18 operates the power regulation device to apply a negative torque to the motor, or increases the braking force of the friction brake, or performs both of these operations.

[0028] In the setting examples of the longitudinal acceleration shown in Fig. 6(b) and Fig. 8(b) described later, the vehicle 1 is decelerated during a period in which the absolute value of the roll angular acceleration increases, and then accelerated during a period in which the absolute value of the roll angular acceleration decreases, but it is not necessary to execute both deceleration and acceleration. In other words, if the vehicle 1 is decelerated during a period in which the absolute value of the roll angular acceleration increases, or if the vehicle 1 is accelerated during a period in which the absolute value of the roll angular acceleration decreases, it is possible to expect the effect of reducing the change in the roll attitude angle Φ of the occupant O.

[0029] (operation) FIG. 7 is a flowchart of a first example of a vehicle control method according to the embodiment. In step S1, the controller 18 detects the roll angular acceleration of the body of the vehicle 1 based on the output signal of the vehicle sensor 12. For example, the controller 18 may calculate the roll angular acceleration of the body by differentiating the detection value of the roll rate sensor of the vehicle sensor 12. In step S2, the controller 18 calculates the roll angular jerk by differentiating the roll angular acceleration. In step S3, the controller 18 calculates the sign of the product obtained by multiplying the roll angular acceleration and the roll angular jerk, inverts the calculated sign, and then multiplies the calculated sign by the set acceleration amount |a| to calculate the corrected longitudinal acceleration Ac.

[0030] In step S4, the controller 18 performs high-pass filtering on the corrected longitudinal acceleration Ac. The high-pass filtering removes steady motion of the vehicle 1, and generates the corrected longitudinal acceleration Ac only when the vehicle 1 is in a transient motion state. In step S5, the controller 18 performs low-pass filtering on the signal after the high-pass filtering. This low-pass filtering reduces the influence of the jerk on the occupant's motion sensation perception by making the change in deceleration or acceleration in the longitudinal direction (i.e., jerk) equal to or less than a set value. In step S6, the controller 18 calculates the target longitudinal acceleration At by adding the corrected longitudinal acceleration Ac to the basic longitudinal acceleration Ab. The controller 18 outputs a control signal to the actuator 17 so that the actual longitudinal acceleration of the vehicle 1 approaches the target longitudinal acceleration At. Then, the process ends.

[0031] (Variation) Another example of setting the longitudinal acceleration will be described with reference to Figures 8(a) and 8(b). If the roll angular acceleration and roll angular jerk are calculated by differentiating the detected value of the roll rate sensor, noise components will increase during the calculation process, and accuracy will likely decrease. Therefore, the controller 18 of the modified example determines, from the detection value of the roll rate sensor (i.e., information on the roll angular velocity), the period during which the absolute value of the roll angular acceleration of the vehicle body increases (i.e., the first phase I-1 and the third phase II-1) and the period during which the absolute value of the roll angular acceleration of the vehicle body decreases (i.e., the second phase I-2 and the fourth phase II-2).

[0032] The roll motion of a vehicle body caused by an external disturbance can basically be thought of as free vibration with the roll center Pc as the center of rotation. In the case of free vibration, the main vibration component is a movement close to its natural period (resonance period). Therefore, the controller 18 calculates the natural period of the roll angle of the vehicle body (hereinafter referred to as "vehicle body roll angle natural period T") and the phase of the roll angular acceleration based on the signal waveform of the roll angular velocity signal output by the roll rate sensor. For example, the controller 18 may determine a peak point pv of the roll angular velocity signal, and calculate, based on the peak point pv, the time when the phase of the roll angular acceleration becomes a reference point (e.g., phase=0 [deg]) and the vehicle body roll angle natural period T. The controller 18 may generate an acceleration pattern of the corrected longitudinal acceleration Ac that decelerates in the first and third quadrants of the roll angular acceleration (i.e., first phase I-1 and third phase II-1) and accelerates in the second and fourth quadrants (i.e., second phase I-2 and fourth phase II-2).

[0033] FIG. 8(a) is a graph showing the time variation of the roll angular acceleration and roll angular velocity of the roll motion caused by the lateral shaking of the vehicle body, and FIG. 8(b) is a graph showing the time variation of the acceleration pattern of the corrected longitudinal acceleration Ac. The controller 18 detects the arrival of a peak point pv of the roll angular velocity signal output from the roll rate sensor, and synchronizes the control timing using the acceleration pattern of FIG. 8(b) with the phase of the vehicle body roll angular velocity of FIG. 8(a) based on the time when the peak point pv arrives and the vehicle body roll angle natural period T. The controller 18 calculates the target longitudinal acceleration At by adding the corrected longitudinal acceleration Ac according to the acceleration pattern to the basic longitudinal acceleration Ab, and controls the actuator 17 so that the actual longitudinal acceleration of the vehicle 1 approaches the target longitudinal acceleration At. This control makes it possible to set a corrected longitudinal acceleration Ac similar to the corrected longitudinal acceleration Ac described with reference to FIGS. 6(a) and 6(b).

[0034] FIG. 9 is a flowchart of a second example of the vehicle control method according to the embodiment. In step S10, the controller 18 acquires a roll angular velocity signal of the body of the vehicle 1 from the roll rate sensor of the vehicle sensor 12. The detected signal is stored in the storage device 18b as a signal data sequence. For example, a signal data sequence for a predetermined period of time may be constantly retained by updating (overwriting) an old signal detected a predetermined period of time ago with a newly acquired signal. By retaining the signal data sequence in the storage device 18b even after the vehicle 1 stops and the power is turned off, the data sequence can be used immediately after the power is turned on again and the vehicle starts traveling.

[0035] In step S11, the controller 18 calculates the vehicle body roll angle natural period T from the data string of the roll angular velocity signal stored in the storage device 18b. For example, the controller 18 may perform frequency analysis on the signal data string to determine the vehicle body roll angle natural period T from its peak. The controller 18 generates an acceleration pattern of the corrected longitudinal acceleration Ac shown in FIG. 8(b) based on the vehicle body roll angle natural period T. In step S12, the controller 18 determines whether or not a peak point pv of the roll angular velocity signal has arrived based on the currently acquired roll angular velocity signal. If the peak point pv has arrived (step S12: Y), the process proceeds to step S13. If the peak point pv has not arrived (step S12: N), the process returns to step S10.

[0036] In step S13, the controller 18 determines the time to start reproducing the acceleration pattern generated in step S11 based on the time when the peak point pv arrives, and reproduces the acceleration pattern from the determined time. The controller 18 adds the corrected longitudinal acceleration Ac according to the acceleration pattern to the basic longitudinal acceleration Ab to calculate the target longitudinal acceleration At, and outputs a control signal to the actuator 17 so that the actual longitudinal acceleration of the vehicle 1 approaches the target longitudinal acceleration At.

[0037] Even during the period during which the controller 18 continues to control the acceleration of the vehicle 1 in accordance with the acceleration pattern generated in step S11 (hereinafter referred to as the "control period"), the controller 18 constantly acquires a roll angular velocity signal in step S14 and continues updating the signal data string stored in the memory device 18b. In step S15, the controller 18 determines whether the control period has ended. If the control period has ended (step S15: Y), the process proceeds to step S16. If the control period has not ended (step S15: N), the process returns to step S13. In step S16, the controller 18 determines whether the vehicle 1 has stopped. If the vehicle 1 has not stopped (step S16: N), the process returns to step S10. In this case, the controller 18 determines the vehicle body roll angle natural period T again and regenerates a new acceleration pattern from the latest natural period information. This makes it possible to deal with factors that affect the vehicle body roll angle natural period T, such as changes in loading conditions such as passengers O, and control of suspensions such as dampers. On the other hand, if the vehicle 1 has stopped (step S16: Y), the process ends.

[0038] (Effects of the embodiment) (1) The vehicle sensor 12 detects the roll angular velocity of the body of the vehicle 1. Based on the detected roll angular velocity, the controller 18 decelerates the vehicle 1 during a period in which the absolute value of the roll angular acceleration of the body increases, and / or accelerates the vehicle 1 during a period in which the absolute value of the roll angular acceleration decreases. This makes it possible to suppress changes in the posture of the occupant O caused by inertial acceleration due to lateral shaking caused by external disturbances such as road irregularities and crosswinds on the vehicle body.

[0039] In particular, in the first half of the lateral sway transient motion in which the absolute value of the roll angular acceleration of the vehicle body increases, by applying deceleration to the vehicle 1 so as to decelerate the trunk of the occupant O in the fore-and-aft direction, the surface pressure of the occupant O's body on the seat back Sb can be reduced, thereby reducing the constraint on the body movement from the seat back Sb. This makes it possible to reduce the movement of the occupant O from being forced to follow the roll movement of the vehicle body, and as a result, it is possible to suppress changes in the posture of the occupant O. Furthermore, in the latter half of the transient roll motion when the absolute value of the roll angular acceleration of the vehicle body decreases, adding acceleration to the vehicle so as to accelerate the trunk of the occupant O in the fore-and-aft direction increases the surface pressure of the occupant O's body on the seat back Sb, thereby increasing the restraint on the body movement from the seat back Sb. This makes it easier for the body movement of the occupant O, which moves with a delay relative to the roll motion of the vehicle body, to follow the seat, thereby ultimately suppressing changes in the occupant's posture.

[0040] (2) The controller 18 may decelerate the vehicle 1 during a period in which the absolute value of the roll angular acceleration increases, and then accelerate the vehicle 1 during a period in which the absolute value of the roll angular acceleration decreases. This makes it possible to suppress changes in the posture of the occupant O caused by inertial acceleration due to lateral shaking caused by disturbances, without interfering with the driver's intentions regarding vehicle movement or the intentions of autonomous driving control or driving assistance control.

[0041] (3) The controller 18 may determine that the absolute value of the roll angular acceleration increases when the sign of the product obtained by multiplying the roll angular jerk and roll angular acceleration of the vehicle body is positive, and may determine that the absolute value of the roll angular acceleration decreases when the sign of the product is negative. This allows the deceleration period and acceleration period for suppressing the change in the posture of the occupant O to be determined. (4) A period during which the absolute value of the roll angular acceleration increases may be determined based on the time when the detected roll angular velocity reaches its peak and the roll resonance period of the vehicle body. Also, a period during which the absolute value of the roll angular acceleration decreases may be determined based on the time when the detected roll angular velocity reaches its peak and the roll resonance period of the vehicle body. This makes it possible to determine the deceleration period and acceleration period for suppressing a change in the posture of the occupant O, even if a sensor that directly detects the roll angular acceleration or the roll angular jerk is unavailable. In addition, because the deceleration period and acceleration period can be determined without differentiating the roll angular velocity, it is possible to avoid an increase in noise and a decrease in calculation accuracy due to differential calculation.

[0042] All examples and conditional terms described herein are intended for educational purposes to aid the reader in understanding the present invention and the concepts provided by the inventor for the advancement of technology, and should be construed without limitation to the specifically described examples and conditions above, and the configuration of examples herein for illustrating the advantages and disadvantages of the present invention. Although the embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0043] 1...vehicle, 10...vehicle control device, 11...object sensor, 12...vehicle sensor, 13...positioning device, 14...map database, 15...communication device, 16...navigation device, 17...actuator, 18...controller, 18a...processor, 18b...storage device, O...occupant, S...vehicle seat, Sb...seat back, Sc...seat cushion

Claims

1. A sensor detects the roll angular velocity of a vehicle body, a controller accelerating the vehicle during a period in which the absolute value of the roll angular acceleration of the vehicle body is decreasing based on the detected roll angular velocity; A vehicle control method comprising:

2. A vehicle control method as described in claim 1, characterized in that the controller decelerates the vehicle during a period in which the absolute value of the roll angular acceleration increases based on the detected roll angular velocity.

3. The vehicle control method described in Claim 2, characterized in that the controller decelerates the vehicle during a period in which the absolute value of the roll angular acceleration increases, and then accelerates the vehicle during a period in which the absolute value of the roll angular acceleration decreases.

4. A vehicle control method described in any one of claims 1 to 3, characterized in that the controller determines that the absolute value of the roll angular acceleration decreases when the sign of the product obtained by multiplying the roll angular jerk of the vehicle body by the roll angular acceleration is negative.

5. A vehicle control method as described in claim 2 or 3, characterized in that the controller determines that the absolute value of the roll angular acceleration increases when the sign of the product obtained by multiplying the roll angular jerk of the vehicle body by the roll angular acceleration is positive.

6. A vehicle control method described in any one of claims 1 to 5, characterized in that the controller determines the period during which the absolute value of the roll angular acceleration decreases based on the time when the detected roll angular velocity reaches its peak and the roll resonance period of the vehicle body.

7. A vehicle control method as described in Claim 2, 3 or 5, characterized in that the controller determines the period during which the absolute value of the roll angular acceleration increases based on the time when the detected roll angular velocity reaches its peak and the roll resonance period of the vehicle body.

8. a sensor for detecting a roll angular velocity of a vehicle body; a controller that accelerates the vehicle by controlling a driving force source that drives the vehicle during a period in which the absolute value of the roll angular acceleration of the vehicle body decreases based on the roll angular velocity detected by the sensor; A vehicle control device comprising:

Images