JP2016150729A - Vehicle motion control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle motion control unit capable of upgrading traveling safety by generating in a vehicle a braking force which does not cause a driver to have a strange feeling during traveling on a curved road, and avoiding danger by generating in the vehicle a braking force which is effective in a case of emergent steering intended to avoid danger.SOLUTION: A vehicle motion control unit 1 includes a lateral G acceleration arithmetic block 21 that calculates a lateral jerk Gyjk, and a correction arithmetic block 23 that uses a low-pass filter to filter a basic braking force target value Bts, which is designated based on the lateral jerk Gyjk, and designates a braking force target value Bt. The vehicle motion control unit 1 generates a braking force dependent on the basic braking force target value Bts. The correction arithmetic block 23 performs filtering to delay a change in the braking force target value Bt to be caused by the basic braking force target value Bts that changes at a higher change rate than a threshold, and raises a cutoff frequency of the low-pass filter when a steering angular speed is high.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle motion control device.

Patent Document 1 describes a motion control device (vehicle motion control device) that assists a driving operation so that the tire force can be used efficiently to drive a curve with a lean driving operation.
The motion control device described in Patent Document 1 generates a braking force by a longitudinal acceleration command value corresponding to a lateral acceleration or a lateral jerk (a differential value of the lateral acceleration), thereby improving running stability.

Japanese Unexamined Patent Publication No. 2011-157067

  The motion control apparatus described in Patent Document 1 sets a control amount (acceleration, braking) based on a lateral acceleration detected by a lateral acceleration sensor (lateral acceleration detecting means). Therefore, if the temporal change rate (lateral jerk) of the lateral acceleration is large in this motion control device, the control amount increases accordingly. For example, when the driver steers a large amount of steering at the entrance (turn-in) of a curve, a large lateral acceleration is generated in the vehicle, and the lateral jerk changes greatly. That is, the motion control device of Patent Document 1 sets a large control amount when the driver steers the steering greatly. This greatly changes the behavior of the vehicle.

The motion control device of Patent Document 1 generates braking force on the vehicle during turn-in to increase the load applied to the front wheels, and effectively uses the tire force (grip force) to turn the vehicle efficiently. However, if the braking force at this time is large, the driver may feel uncomfortable.
On the other hand, it is preferable that a large braking force is generated when the driver steers the steering largely for emergency evacuation.

  Therefore, the present invention improves the stability of the running by generating a braking force on the vehicle that does not give the driver a sense of incongruity during curve driving, and provides the vehicle with an effective braking force during emergency steering for avoiding danger. It is an object of the present invention to provide a vehicle motion control device that can be generated to avoid danger.

  In order to solve the above-mentioned problems, the present invention provides a lateral jerk calculating unit for differentiating an actual lateral acceleration of a vehicle detected by a lateral acceleration detecting means to calculate a lateral jerk, and a reference for a braking force target value based on the lateral jerk. A braking force target value calculation unit that sets a value, and a correction calculation unit that sets the braking force target value by filtering the reference value with a low-pass filter, and the braking force according to the braking force target value The vehicle motion control device is configured to adjust the longitudinal acceleration of the vehicle generated by a braking force generation unit. The correction calculation unit causes a delay in the change of the braking force target value with respect to the reference value that changes at a change speed higher than a threshold by the filtering, and when the steering angular speed of the steering wheel is higher than a predetermined value, The cutoff frequency of the low-pass filter is made higher than when the steering angular velocity is lower than the predetermined value.

According to the present invention, the reference value set by the braking force target value calculation unit according to the lateral jerk is filtered by the low pass filter to set the braking force target value, and the braking force according to the braking force target value is generated in the vehicle. .
The braking force target value changes behind the reference value when the reference value changes at a change rate higher than the threshold value. Since the low-pass filter can remove a high-frequency component when the reference value changes, the change in the reference value at a high change rate can be delayed. Therefore, when the reference value changes at a change speed higher than the threshold value, the braking force generated in the vehicle changes gradually, and the running stability of the vehicle improves. Also, since the braking force changes gently, the driver feels uncomfortable.
Furthermore, when the steering angular velocity of the steering wheel is higher than a predetermined value, the low-pass filter has a higher cutoff frequency. As the cut-off frequency of the low-pass filter increases, the rate of change that causes delay increases. For this reason, when the cut-off frequency of the low-pass filter is increased, the threshold value at which the change in the braking force target value is moderate with respect to the change in the reference value is increased. And in the case of emergency steering for avoiding danger, the steering angular velocity of the steering wheel becomes high. Therefore, during emergency steering, the braking force target value is set so as to change without delay to the reference value that changes at a high change speed. For this reason, during emergency steering, the braking force is generated in the vehicle as set by the braking force target value calculation unit, and danger is effectively avoided.

Further, the braking force target value calculation unit sets the reference value when the lateral jerk is positive.
The lateral jerk becomes positive when the actual lateral acceleration increases. For example, when the vehicle changes from straight running to turning, the actual lateral acceleration increases, so the lateral jerk becomes positive.
Therefore, according to the present invention, it is possible to generate a braking force when the vehicle changes from straight running to turning. When braking force is generated in the vehicle, a load is applied to the front wheels, so that the vehicle can be turned by effectively using the tire force of the front wheels.

Further, the braking force target value calculation unit sets the larger reference value as the lateral jerk increases.
According to the present invention, a large braking force can be generated in a vehicle in which the lateral acceleration changes greatly, and the traveling of the vehicle can be stabilized.

  According to the present invention, the braking force is generated in the vehicle so that the driver does not feel uncomfortable in the curve driving, thereby improving the driving stability, and the braking force that is effective in emergency steering for avoiding danger is generated in the vehicle. Thus, it is possible to provide a vehicle motion control device that can avoid danger.

It is a figure which shows a vehicle provided with a vehicle motion control apparatus. It is a functional block diagram of a vehicle motion control device. It is a figure which shows the relationship between a steering angle when driving | running | working the driving | running | working road where the vehicle is curving, an actual lateral acceleration, and a lateral jerk. It is a functional block diagram of a correction | amendment calculating part. It is a figure which shows the characteristic of a braking force filter. It is a functional block diagram of an emergency steering judgment part. It is a figure which shows the characteristic of the braking force filter by which the cutoff frequency was changed. It is a figure which shows the change of the braking force target value with respect to the change of a reference | standard braking force target value. It is a figure which shows the example of a design change of a determination map and a signal generation part.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
FIG. 1 is a diagram illustrating a vehicle including a vehicle motion control device.
As shown in FIG. 1, the vehicle motion control device 1 is provided in a vehicle 10. The vehicle 10 shown in FIG. 1 is a rear wheel drive that travels by driving the rear wheel WR with the power output from the power source 11, but the drive type of the vehicle 10 is not limited. The vehicle 10 may be a front wheel drive that travels with the front wheel WF being driven, or may be a four wheel drive. The power source 11 may be an internal combustion engine such as a gasoline engine or a diesel engine, or may be an electric motor. Further, a hybrid type in which an internal combustion engine and an electric motor are combined may be used.

  The vehicle motion control device 1 includes a microcomputer (Central Processing Unit), a ROM (Read Only Memory), a microcomputer (Random Access Memory), and peripheral devices (not shown).

The vehicle 10 includes a steering device 12 and a braking device 13.
The steering device 12 includes a steering wheel 121 and a steering motor 122. The steered motor 122 displaces the rack shaft 123 to steer the front wheels WF. Further, the steering angle when the steering wheel 121 is steered is detected by the steering angle sensor 121a. A detection signal (steering angle signal Sh) of the steering angle sensor 121a is input to the vehicle motion control device 1. The vehicle motion control device 1 calculates the steering angle of the steering wheel 121 based on the steering angle signal Sh, and drives the steering motor 122 based on the calculated steering angle. The front wheels WF are steered at an angle corresponding to the steering angle of the steering wheel 121 by driving the steering motor 122. Thus, the steering device 12 is a steer-by-wire in which the steered motor 122 is driven by the control of the vehicle motion control device 1 according to the steering angle of the steering wheel 121 and the front wheels WF are steered.

  The steering device 12 is provided with a reaction force motor (not shown). The reaction force motor inputs torque (reaction force torque) to the steering wheel 121. The reaction force motor is controlled by the vehicle motion control device 1. The vehicle motion control device 1 drives a reaction force motor corresponding to the steering angle of the steering wheel 121 and inputs a reaction torque corresponding to the steering angle to the steering wheel 121. As a result, the driver who steers the steering wheel 121 feels an appropriate reaction force, and the steering feel is improved.

  The braking device 13 includes a brake pedal 131 and a braking force generation unit (brake operation unit 132). The brake operation unit 132 is, for example, a disc brake, and generates a braking force by sandwiching the brake disc 132a with the brake hydraulic pressure generated by the hydraulic pressure generation unit 133. The operation amount (brake stroke) when the brake pedal 131 is depressed is detected by the brake sensor 131a. A detection signal (braking signal Sb) of the brake sensor 131a is input to the vehicle motion control device 1. The vehicle motion control device 1 calculates a brake stroke based on the braking signal Sb, and drives the actuator 133a of the hydraulic pressure generating unit 133 based on the calculated brake stroke. The hydraulic pressure generator 133 is driven by the actuator 133a to generate a brake hydraulic pressure corresponding to the brake stroke. As described above, the braking device 13 is a brake-by-wire in which the actuator 133a is driven by the control of the vehicle motion control device 1 in accordance with the operation amount (brake stroke) of the brake pedal 131 and the brake operation unit 132 is driven. .

  The vehicle 10 is provided with a throttle pedal 111. The operation amount (throttle stroke) when the throttle pedal 111 is depressed is detected by the throttle sensor 111a. A detection signal (throttle signal Sa) of the throttle sensor 111a is input to the vehicle motion control device 1. The vehicle motion control device 1 calculates the throttle stroke based on the throttle signal Sa, and adjusts the power output from the power source 11 based on the calculated throttle stroke. For example, when the power source 11 is a gasoline engine, the vehicle motion control device 1 controls the throttle valve (not shown) based on the throttle stroke to set the throttle opening. As described above, the vehicle 10 is a drive-by-wire in which the power output from the power source 11 is adjusted by the control of the vehicle motion control device 1 according to the operation amount (throttle stroke) of the throttle pedal 111.

Further, the vehicle 10 includes a lateral acceleration detection means (lateral acceleration sensor 14), a longitudinal acceleration sensor 15, and a vehicle speed sensor 16.
The lateral acceleration sensor 14 is a sensor that detects lateral acceleration generated in the vehicle 10, and a detection signal (lateral acceleration signal Sgy) is input to the vehicle motion control device 1. The vehicle motion control device 1 calculates the lateral acceleration (actual lateral acceleration Gr) generated in the vehicle 10 based on the lateral acceleration signal Sgy.
The longitudinal acceleration sensor 15 is a sensor that detects longitudinal acceleration generated in the vehicle 10, and a detection signal (longitudinal acceleration signal Sgx) is input to the vehicle motion control device 1. The vehicle motion control device 1 calculates the longitudinal acceleration generated in the vehicle 10 based on the longitudinal acceleration signal Sgx.
The vehicle speed sensor 16 is a rotation speed sensor that detects the rotation speed of wheels (front wheels WF, rear wheels WR), for example. The vehicle speed sensor 16 outputs a pulse signal (wheel speed signal Sw) according to the rotation of the wheel. The vehicle motion control device 1 calculates the vehicle speed (vehicle speed) of the vehicle 10 based on the wheel speed signal Sw.

  Although omitted in FIG. 1, pulse signals are input from the four vehicle speed sensors 16 to the vehicle motion control device 1. The vehicle motion control device 1 may use one of the four pulse signals (for example, the pulse signal having the maximum pulse width) as the wheel speed signal Sw, and the average of the four pulse signals (average pulse width) may be the wheel speed signal. It may be Sw.

FIG. 2 is a functional block diagram of the vehicle motion control device. As shown in FIG. 2, the vehicle motion control device 1 includes a lateral jerk calculation unit (lateral G acceleration calculation unit 21), a GVC (G-Vectoring Control) calculation unit 22, and a correction calculation unit 23. Is done.
The lateral G acceleration calculation unit 21 calculates an actual lateral acceleration (actual lateral acceleration Gr) generated in the vehicle 10 (see FIG. 1) based on the lateral acceleration signal Sgy input from the lateral acceleration sensor 14. Further, the lateral G acceleration calculation unit 21 differentiates the calculated actual lateral acceleration Gr to calculate a temporal change rate (lateral jerk Gyjk) of the lateral acceleration. The lateral jerk Gyjk is input to the GVC calculator 22. The actual lateral acceleration Gr is input to the correction calculation unit 23.

  The GVC calculating unit 22 outputs a control amount (GVC control amount) such that the vehicle 10 (see FIG. 1) accelerates or decelerates in proportion to the lateral jerk Gyjk. For example, when the vehicle 10 travels on a curve, the GVC calculating unit 22 outputs a GVC control amount for adjusting the longitudinal acceleration to stabilize the traveling. Such a GVC control amount is set, for example, as a value obtained by multiplying a numerical value (absolute value) of the lateral jerk Gyjk by a predetermined gain (Gc) (GVC control amount = Gc × | lateral jerk Gyjk |).

FIG. 3 is a diagram illustrating a relationship among a steering angle, an actual lateral acceleration, and a lateral jerk when the vehicle travels on a curved road. In FIG. 3, the solid line indicates straight traveling in a straight section, and the broken line indicates turning traveling in a curve (curved section).
At the start of turning, the vehicle 10 is in a state of changing from straight running to turning. Since the steering wheel 121 (see FIG. 1) is increased at the start of turning, the steering angle θh increases (graph A). Since the vehicle 10 starts to turn, the actual lateral acceleration Gr increases (graph B), and the lateral jerk Gyjk becomes positive (graph C).
Thereafter, the vehicle 10 enters a steady circular turning state. In this state, since the vehicle 10 travels on a curve that curves with a constant curvature, the steering angle θh is maintained constant (graph A). When the steering angle θh is kept constant, the actual lateral acceleration Gr becomes constant (graph B), and the lateral jerk Gyjk becomes zero (graph C).
At the end of turning, the vehicle 10 is in a state of changing from turning to straight running. At the end of turning, the steering wheel 121 is turned back, so that the steering angle θh decreases (graph A). Since the vehicle 10 shifts from turning to straight traveling, the actual lateral acceleration Gr decreases (graph B) and the lateral jerk Gyjk becomes negative (graph C).
As described above, in the vehicle 10 traveling on the curved traveling road, the actual lateral acceleration Gr changes, and the lateral jerk Gyjk changes accordingly.

The GVC calculating unit 22 shown in FIG. 2 determines that the turn is started when the lateral jerk Gyjk is positive, and outputs a GVC control amount to decelerate the vehicle 10 (see FIG. 1). When the lateral jerk Gyjk is positive, the GVC calculating unit 22 of the present embodiment outputs a GVC control amount (reference braking force target value Bts) that serves as a reference for the braking force target value (braking force target value).
The GVC calculating unit 22 determines that the turn is over when the lateral jerk Gyjk is negative, and outputs a GVC control amount to accelerate the vehicle 10 (see FIG. 1). When the lateral jerk Gyjk is negative, the GVC calculation unit 22 of the present embodiment outputs a GVC control amount (reference driving force target value Pts) that serves as a reference for the driving force target value (driving force target value).
In the present embodiment, the GVC calculation unit 22 serves as a control target value calculation unit that sets target values of braking force and driving force.

When the power source 11 (see FIG. 1) is an electric motor, or when the power source 11 is a hybrid type in which an internal combustion engine and an electric motor are combined, the GVC calculation unit 22 is generated by the electric motor when it is determined that turning is started. A reference value of the target value of the regenerative braking force (reference braking force target value Bts) is output as a GVC control amount. In this case, the power source 11 (electric motor) that generates the regenerative braking force serves as the braking force generator.
In addition, when it is determined that the turn is over, the GVC calculating unit 22 outputs a reference value (reference driving force target value Pts) of the target value of power output by the power running of the electric motor as a GVC control amount.

  The control (GVC) in which the GVC calculating unit 22 sets and outputs the GVC control amount is described in detail in the above-mentioned Patent Document 1, the patent document cited in Patent Document 1 (Patent No. 3733929), and the like. Can be used.

The reference driving force target value Pts output by the GVC calculating unit 22 at the end of turning of the vehicle 10 (see FIG. 1) is input to the driving force control signal generating unit 24b. The driving force control signal generation unit 24b sets a control signal (driving force control signal Cp) such that a driving force corresponding to the reference driving force target value Pts is generated in the power source 11.
The driving force control signal Cp set by the driving force control signal generation unit 24b is output from the vehicle motion control device 1 and input to a control unit (not shown) of the power source 11. The power source 11 is driven based on the driving force control signal Cp to generate driving force. Thus, the driving force generated in the power source 11 is a driving force corresponding to the lateral jerk Gyjk.

At the start of turning of the vehicle 10 (see FIG. 1), the reference braking force target value Bts set by the GVC calculating unit 22 is input to the correction calculating unit 23.
In addition, the actual lateral acceleration Gr and lateral jerk Gyjk calculated by the lateral G acceleration calculating unit 21 and the steering angle signal Sh output from the steering angle sensor 121a are input to the correction calculating unit 23.

  Then, the correction calculation unit 23 corrects the reference braking force target value Bts based on the steering angle θh of the steering wheel 121 (see FIG. 1), the actual lateral acceleration Gr, and the lateral jerk Gyjk. The corrected reference braking force target value Bts is output from the correction calculation unit 23 as the braking force target value Bt.

The braking force target value Bt output from the correction calculation unit 23 is input to the braking force control signal generation unit 24a.
The braking force control signal generation unit 24a generates a control signal (fluid) that causes the hydraulic pressure generation unit 133 to generate a brake hydraulic pressure that causes the braking operation unit 132 (see FIG. 1) to generate a braking force corresponding to the braking force target value Bt. Pressure control signal Cb) is set.

The hydraulic pressure control signal Cb set by the braking force control signal generation unit 24 a is output from the vehicle motion control device 1 and input to the actuator 133 a of the hydraulic pressure generation unit 133 of the braking device 13. The actuator 133a is driven based on the hydraulic pressure control signal Cb, and the hydraulic pressure generator 133 generates brake hydraulic pressure.
The brake operating unit 132 (see FIG. 1) is driven by the brake hydraulic pressure generated by the hydraulic pressure generating unit 133, and braking force is generated in the front wheel WF (see FIG. 1) and the rear wheel WR (see FIG. 1). The braking force generated on the front wheel WF and the rear wheel WR is a braking force corresponding to the lateral jerk Gyjk.

As described above, when the lateral jerk Gyjk is positive, the GVC calculation unit 22 determines that the turn is started and sets the reference braking force target value Bts. The GVC calculation unit 22 sets a larger reference braking force target value Bts as the lateral jerk Gyjk increases. Then, the brake operation unit 132 (see FIG. 1) is operated by the hydraulic pressure control signal Cb based on the braking force target value Bt in which the reference braking force target value Bts set by the GVC calculating unit 22 is corrected, and the braking force is generated. To do.
For example, the GVC calculation unit 22 uses a value obtained by multiplying a numerical value (absolute value) of the lateral jerk Gyjk by a predetermined gain (Gc) as a target longitudinal acceleration, and a reference that causes such longitudinal acceleration (deceleration). A braking force target value Bts is set.

When braking force is generated in the vehicle 10 (see FIG. 1), a load is applied to the front wheel WF (see FIG. 1). The front wheel WF is a steered wheel that steers according to the steering angle θh of the steering wheel 121 (see FIG. 1). Therefore, when braking force is generated at the start of turning and a load is applied to the front wheels WF, it is possible to perform steering using tire force (grip force) effectively.
In other words, the vehicle motion control device 1 having the GVC calculating unit 22 can realize an efficient and stable turn using the tire force effectively by generating a braking force at the start of the turn.
As the lateral jerk Gyjk increases, a larger reference braking force target value Bts is set, and the braking force generated in the vehicle 10 increases. Therefore, since the load applied to the front wheel WF increases as the lateral jerk Gyjk increases, the load applied to the front wheel WF increases when the steering wheel 121 starts to be steered in the initial stage at the start of turning. As a result, the tire force is effectively utilized particularly in the initial stage at the start of turning.

Further, the GVC calculating unit 22 determines that the turn is over when the lateral jerk Gyjk is negative, and sets the reference driving force target value Pts. Then, the power source 11 is operated by the driving force control signal Cp based on the reference driving force target value Pts set by the GVC calculating unit 22 to generate driving force.
As a result, the vehicle 10 (see FIG. 1) efficiently accelerates at the end of the turn when the vehicle moves from a turn on a curve to a straight run on a straight section.
That is, the vehicle motion control device 1 having the GVC calculating unit 22 can realize efficient acceleration by generating a driving force at the end of turning.

FIG. 4 is a functional block diagram of the correction calculation unit. FIG. 5 is a diagram showing characteristics of the braking force filter.
The correction calculation unit 23 includes a braking force filter 23B. The reference braking force target value Bts set by the GVC calculating unit 22 (see FIG. 2) is input to the braking force filter 23B.
As shown in FIG. 5, the braking force filter 23B is a low-pass filter (LPF).
Then, the correction calculation unit 23 filters the reference braking force target value Bts with the braking force filter 23B (LPF), and outputs the filtered reference braking force target value Bts as the braking force target value Bt.

  As described above, the braking force filter 23B of the present embodiment is a low pass filter (LPF). When the amount of change in the input signal is small (when the input signal changes gently), the low-pass filter outputs the input signal as it is. On the other hand, when the temporal change amount of the input signal is large (when the change speed of the input signal is high), the low-pass filter outputs the input signal with a reduced gain. That is, the change speed of the input signal is reduced by the low-pass filter.

Like “CASE (A)” shown in FIG. 5, a cut-off frequency (normal cut-off frequency (value: value: threshold value) whose change speed (magnitude: 1 / Δt1) of the reference braking force target value Bts as an input signal is a threshold value. 1 / sn)), the output signal (braking force target value Bt) from the braking force filter 23B is equal to the input signal (reference braking force target value Bts) (Bt = Bts).
In the present embodiment, the magnitude of the change speed of the input signal (reference braking force target value Bts) is the speed (frequency component) when the input signal changes over time (Δt1) by a predetermined unit amount (1). ). That is, the shorter the time required to change by a predetermined unit amount, the higher the change speed, indicating that the input signal is changing rapidly.
Further, the value (1 / sn) of the normal cut-off frequency in the braking force filter 23B is a value that is appropriately determined according to the running performance required for the vehicle 10 (see FIG. 1).

  In addition, as in “CASE (B)” shown in FIG. 5, the magnitude (1 / Δt2) of the change speed of the reference braking force target value Bts that is the input signal is greater than the value (1 / sn) of the normal cutoff frequency. If it is larger, the output signal (braking force target value Bt) is output with a gain smaller than 1 (α in the example shown in FIG. 5) with respect to the reference braking force target value Bts (Bt = α × Bts). Then, as shown by the solid line, the braking force target value Bt changes gradually with respect to the change of the reference braking force target value Bts shown by the broken line.

  As described above, when the change speed of the reference braking force target value Bts is high (CASE (B)), the correction calculation unit 23 (see FIG. 2) of the present embodiment uses the braking force filter 23B (low-pass filter) to generate the reference braking force. The change in the target value Bts is attenuated and output as the braking force target value Bt. That is, when the changing speed of the reference braking force target value Bts is larger than the threshold (normal cut-off frequency), the correction calculation unit 23 reduces the response speed and outputs the braking force target value Bt.

  Further, as shown in FIG. 4, the correction calculation unit 23 includes an emergency steering determination unit 230. The emergency steering determination unit 230 receives the steering angle signal Sh, the reference braking force target value Bts, and the actual lateral acceleration Gr. The emergency steering determination unit 230 outputs a boundary value fluctuation signal SigFB based on the actual lateral acceleration Gr and the reference braking force target value Bts. The correction calculation unit 23 changes the threshold value (cut-off frequency) in the braking force filter 23B based on the boundary value fluctuation signal SigFB.

FIG. 6 is a functional block diagram of the emergency steering determination unit.
As shown in FIG. 6, the emergency steering determination unit 230 has a map determination unit 232. The map determination unit 232 has a determination map MP23. The determination map MP23 is a map showing an emergency steering area corresponding to the actual lateral acceleration Gr and the requested deceleration Ra (deceleration requested by the GVC calculating unit 22). Such a determination map MP23 is set in advance by prior experimental measurement or simulation.

  The emergency steering determination unit 230 includes a deceleration conversion unit 231. The deceleration conversion unit 231 converts the reference braking force target value Bts into a deceleration, and outputs the converted deceleration as the requested deceleration Ra. For example, the deceleration conversion unit 231 converts the reference braking force target value Bts into a deceleration (required deceleration Ra) based on a map (not shown) indicating the deceleration corresponding to the reference braking force target value Bts. .

When the vehicle motion control device 1 (see FIG. 2) determines that the turn is started by the GVC calculation unit 22 (see FIG. 2), the map determination unit 232 of the emergency steering determination unit 230 determines the actual lateral acceleration Gr and the requested deceleration. Based on Ra, it is determined whether emergency steering (EMG) or normal steering (NORM).
The map determining unit 232 determines that the steering is normal when the required deceleration Ra with respect to the actual lateral acceleration Gr is in the normal region (NORM) indicated by the hatched portion in the determination map MP23 (an example is indicated by Xn). The map determination unit 232 determines that the steering is emergency when the required deceleration Ra with respect to the actual lateral acceleration Gr is in the emergency region (EMG) indicated by the dot portion in the determination map MP23 (an example is indicated by Xe).

Further, the emergency steering determination unit 230 of this embodiment includes a steering angular velocity calculation unit 233a and a steering angular velocity determination unit 233b. The steering angular velocity calculation unit 233a calculates the steering angle θh and the steering angular velocity θv of the steering wheel 121 (see FIG. 1) based on the steering angle signal Sh. The steering angular velocity calculation unit 233a calculates the steering angular velocity θv by differentiating the steering angle θh. The steering angular velocity θv calculated by the steering angular velocity calculation unit 233a is input to the steering angular velocity determination unit 233b.
The steering angular velocity determination unit 233b determines emergency steering when the input steering angular velocity θv is higher than a predetermined value. Further, the steering angular velocity determination unit 233b determines that the steering is normal when the steering angular velocity θv is equal to or less than a predetermined value.
The predetermined value of the steering angular velocity θv when the steering angular velocity determination unit 233b determines emergency steering is a value that is appropriately determined according to the travel performance required for the vehicle 10 (see FIG. 1).

  For example, when the vehicle 10 (see FIG. 1) is traveling at a low speed, the actual lateral acceleration Gr may not occur even when the steering angular velocity θv is high. The emergency steering determination unit 230 includes a steering angular velocity determination unit 233b, and is configured to be able to determine emergency steering based on the steering angular velocity θv, so that emergency steering can be performed accurately even when the vehicle 10 is traveling at a low speed. Can be determined.

The emergency steering determination unit 230 includes a signal generation unit 234. The signal generator 234 outputs the boundary value fluctuation signal SigFB.
When the map determination unit 232 and the steering angular velocity determination unit 233b both determine normal steering, the emergency steering determination unit 230 sets the boundary value fluctuation signal SigFB to an OFF signal and outputs it from the signal generation unit 234. Further, when at least one of the map determination unit 232 and the steering angular velocity determination unit 233b determines emergency steering, the emergency steering determination unit 230 sets the boundary value fluctuation signal SigFB to an ON signal and outputs it from the signal generation unit 234.

  As described above, the emergency steering determination unit 230 determines whether the steering is the normal steering (NORM) or the emergency steering (EMG) according to the actual lateral acceleration Gr and the requested deceleration Ra (reference braking force target value Bts). Further, the emergency steering determination unit 230 determines whether normal steering (NORM) or emergency steering (EMG) according to the steering angular velocity θv. The emergency steering determination unit 230 outputs the boundary value fluctuation signal SigFB set to the OFF signal when it is determined as normal steering (NORM), and the boundary value fluctuation signal SigFB set as the ON signal when it is determined as emergency steering (EMG). Is output.

When the boundary value fluctuation signal SigFB output from the emergency steering determination unit 230 is an ON signal, the correction calculation unit 23 illustrated in FIG. 4 changes the threshold value (cutoff frequency) in the braking force filter 23B.
FIG. 7 is a diagram showing the characteristics of the braking force filter with the cutoff frequency changed. As shown in FIG. 7, when the boundary value fluctuation signal SigFB is an ON signal, the correction calculation unit 23 (see FIG. 4) sets the cutoff frequency to an emergency cutoff frequency (value: higher than the normal cutoff frequency (broken line)). 1 / se) (solid line).

Note that the emergency cut-off frequency value (1 / se) is a value that is appropriately determined according to the travel performance required for the vehicle 10 (see FIG. 1).
For example, the value (1 / se) of the emergency cut-off frequency is based on the magnitude (1 / Δt2) of the change speed at which the change of the reference braking force target value Bts is attenuated in “CASE (B)” of FIG. Is also set larger.
In this case, as indicated by “CASE (B)” in FIG. 7, the output from the braking force filter 23 </ b> B even if the magnitude (1 / Δt <b> 2) of the change speed of the reference braking force target value Bts serving as the input signal is large. The signal (braking force target value Bt) becomes equal to the input signal (reference braking force target value Bts) (Bt = Bts). That is, an input signal (reference braking force target value Bts) that changes at a high change speed is output as the braking force target value Bt without being attenuated.
Thus, in the example shown in FIG. 7, even when the change rate of the reference braking force target value Bts is high “CASE (B)”, the change rate of the reference braking force target value Bts is low “CASE (A As in “)”, the braking force target value Bt is output without the change in the reference braking force target value Bts being attenuated.

  The correction calculation unit 23 (see FIG. 4) sets the threshold value (cut-off frequency) to the emergency cutoff when the boundary value fluctuation signal SigFB output from the emergency steering determination unit 230 is switched from the ON signal to the OFF signal. Return from frequency to normal cut-off frequency.

FIG. 8 is a diagram illustrating a change in the braking force target value with respect to a change in the reference braking force target value.
When the reference braking force target value Bts changes as shown by the solid line in FIG. 8, the braking force target value Bt changes as shown by the broken line.

When the lateral jerk Gyjk is positive, the GVC calculating unit 22 (see FIG. 2) of the vehicle motion control device 1 determines that the vehicle is turning and outputs a reference braking force target value Bts.
At this time, if the emergency steering determination unit 230 (see FIG. 4) determines normal steering (NORM), the correction calculation unit 23 (see FIG. 4), as shown in FIG. Frequency) is set to the normal cutoff frequency (value: 1 / sn).
Therefore, as shown in FIG. 8, when the change speed of the reference braking force target value Bts is high (particularly when the reference braking force target value Bts is generated or canceled), the normal braking force target value Bt is set to the reference control value. It changes gently with respect to the change of the power target value Bts. As a result, the target value of the braking force generated in the vehicle 10 (see FIG. 1) changes gently, so that the braking force generated in the vehicle 10 changes gently. In this manner, in the case of normal steering, the braking force generated in the vehicle 10 changes gently, so that the driver feels uncomfortable.

On the other hand, when the emergency steering determination unit 230 (see FIG. 4) determines emergency steering (EMG) at the start of turning, the correction calculation unit 23 (see FIG. 4), as shown in FIG. Is set to the emergency cutoff frequency (value: 1 / se). The emergency cutoff frequency value (1 / se) is set to be larger than the normal cutoff frequency value (1 / sn).
Therefore, as shown in FIG. 8, even if the changing speed of the reference braking force target value Bts is high, the braking force target value Bt quickly changes following the change of the reference braking force target value Bts during emergency steering. As a result, the target value of the braking force generated in the vehicle 10 (see FIG. 1) changes following the change in the reference braking force target value Bts quickly, so that the braking force generated in the vehicle 10 is the reference braking force target value. Immediately follow changes in Bts. In this way, in the case of emergency steering, the braking force generated in the vehicle 10 changes rapidly following the reference braking force target value Bts, so the GVC calculation unit 22 (see FIG. 2) is set in the vehicle 10. A braking force is generated on the street.

  Emergency steering is often steering in a state where danger avoidance is required, such as collision avoidance of the vehicle 10 (see FIG. 1). Therefore, danger is effectively avoided by generating braking force on the vehicle 10 as set by the GVC calculating unit 22 (see FIG. 2) during emergency steering.

  Note that the design of the present invention can be changed as appropriate without departing from the spirit of the invention.

FIG. 9 is a diagram illustrating a design change example of the determination map and the signal generation unit.
For example, as shown in FIG. 9, in the emergency region (EMG), a map determination unit 232a having a determination map MP23a weighted by a plurality of levels (for example, four levels LV1 to LV4) may be used. . Alternatively, the signal generator 234a may select a plurality of (for example, four) cutoff frequencies (values: FB1 to FB4) corresponding to the degree of urgency. Then, the map determination unit 232a sets the urgency level from the determination map MP23a based on the actual lateral acceleration Gr and the requested deceleration Ra, and the signal generation unit 234a selects a cutoff frequency value corresponding to the urgency level. It may be a configuration. In this case, the emergency steering determination unit 230 (see FIG. 2) outputs the value of the cutoff frequency selected by the signal generation unit 234a as the boundary value fluctuation signal SigFB.
And the correction | amendment calculating part 23 (refer FIG. 4) may be the structure which changes the value of the cutoff frequency of the braking force filter 23B (refer FIG. 7) based on the boundary value fluctuation signal SigFB.

For example, when the required deceleration Ra with respect to the actual lateral acceleration Gr is indicated by Xe in the determination map MP23a, the map determination unit 232a determines that the emergency steering emergency level is “LV2”. Then, the emergency steering determination unit 230 selects “FB2” corresponding to the urgency level of “LV2” as the cutoff frequency value at the signal generation unit 234a, and outputs the value “FB2” as the boundary value fluctuation signal SigFB. .
The correction calculator 23 (see FIG. 4) sets the cutoff frequency value of the braking force filter 23B (see FIG. 7) to “FB2” based on the boundary value fluctuation signal SigFB.
With such a configuration, the braking force can be suitably generated in the vehicle 10 (see FIG. 1) according to the urgent level of emergency steering, and the running stability can be improved more effectively.

Further, in the vehicle 10 of the present embodiment shown in FIG. 1, the power source 11, the steering device 12, and the braking device 13 are configured by-by-wire (drive-by-wire, steer-by-wire, brake-by-wire).
The configuration is not limited to this, and a throttle valve (not shown) of the power source 11 may be mechanically connected to the throttle pedal 111. In this case, the throttle valve may be configured to be controlled by the vehicle motion control device 1 independently of the operation of the throttle pedal 111.
Similarly, the steering wheel 121 and the rack shaft 123 may be mechanically connected. In this case, the rack shaft 123 only needs to be configured to be displaceable by the steering motor 122.
Similarly, the brake pedal 131 and the hydraulic pressure generator 133 may be mechanically connected. In this case, it is only necessary that the hydraulic pressure generating unit 133 can generate the brake hydraulic pressure by driving the actuator 133a.

DESCRIPTION OF SYMBOLS 1 Vehicle motion control apparatus 10 Vehicle 14 Lateral acceleration sensor (lateral acceleration detection means)
21 Lateral G acceleration calculation unit (lateral jerk calculation unit)
22 GVC calculation part (braking force target value calculation part)
23 Correction calculation unit 132 Brake operation unit (braking force generation unit)
Bts Reference braking force target value (braking force target value)
Gr Actual lateral acceleration Gyjk Lateral jerk

Claims (3)

A lateral jerk calculating unit that calculates the lateral jerk by differentiating the actual lateral acceleration of the vehicle detected by the lateral acceleration detecting means;
A braking force target value calculation unit for setting a reference value of the braking force target value based on the lateral jerk;
A correction calculation unit that sets the braking force target value by filtering the reference value with a low-pass filter,
In the vehicle motion control device that adjusts the longitudinal acceleration of the vehicle by generating a braking force according to the braking force target value in a braking force generator,
The correction calculation unit is
The filtering causes a delay in the change of the braking force target value with respect to the reference value that changes at a change speed higher than a threshold value,
The vehicle motion control device characterized in that when the steering angular velocity of the steering wheel is higher than a predetermined value, the cutoff frequency of the low-pass filter is made higher than when the steering angular velocity is lower than the predetermined value.   The vehicle motion control device according to claim 1, wherein the braking force target value calculation unit sets the reference value when the lateral jerk is positive.   The vehicle motion control device according to claim 2, wherein the braking force target value calculation unit sets the larger reference value as the lateral jerk increases.

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