JP3417091B2 - Vehicle yawing momentum control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention calculates a target yawing momentum from an input acting on a vehicle, a physical amount generated in the vehicle, and the like, and calculates a yawing momentum actually occurring in the vehicle.
The present invention relates to a yawing momentum control device for a vehicle that performs feedback control so as to match the target yawing momentum, and particularly to a fastening force control device or a differential limiting device for a driving force distribution clutch between front and rear wheels or between left and right wheels that enables this feedback control. Device, braking force control device for wheel cylinders provided on each wheel of the vehicle, stabilizer control device or active suspension device with variable roll rigidity between the left and right wheels, and individual control of steering angles for each wheel It is applicable to a possible four-wheel steering device or the like.

[0002]

2. Description of the Related Art An application of such a yawing momentum control device for a vehicle to, for example, a fastening force control device for a driving force distribution clutch between the front and rear wheels or between the left and right wheels has been previously proposed by the present applicant. There is one described in Japanese Patent Laid-Open No. 3-31030. In this engagement force control device for a driving force distribution clutch, specifically, a clutch having a variable engagement force is interposed between the front and rear wheels or between the left and right wheels of a vehicle, and the engagement force of the clutch is controlled so that the engine can be operated. The driving force transmitted to each wheel can be variably controlled, and the yawing momentum generated in the vehicle can be controlled by controlling the driving force of each wheel.

Here, for example, when the driving force distribution control is performed between the front and rear wheels of a vehicle, the driving force applied to each wheel during turning or steering is based on the concept of a friction circle, particularly if only the driving force is discussed. As the force increases, the cornering force of the wheel decreases. Therefore, if the driving force applied to the front wheels during steered turn is increased relative to that applied to the rear wheels, the cornering force of the front wheels is reduced, so that the yawing momentum generated in the vehicle, specifically, the yaw rate and The yaw angular acceleration is reduced, the yaw moment acting on the vehicle is reduced, and the steering characteristic of the vehicle changes in the understeer direction. Conversely, if the driving force applied to the front wheels during steered turning is reduced relative to that applied to the rear wheels, the cornering force of the front wheels will increase, so the yaw rate and yaw angular acceleration of the vehicle such as yaw rate are occurring. The momentum increases, the yaw moment acting on the vehicle increases, and the steering characteristic of the vehicle changes in the oversteer direction.

Further, for example, when the driving force distribution control is performed between the rear left and right wheels of the vehicle, if the driving force to the rear wheel that becomes the turning outer wheel is increased relative to that to the rear wheel that becomes the turning inner wheel. The yaw moment acting on the vehicle increases and the yaw rate and yaw momentum of the yaw angular acceleration generated on the vehicle increase, and the steering characteristic of the vehicle changes in the oversteer direction. On the contrary, if the driving force to the rear wheel that becomes the outer turning wheel is reduced relative to that to the rear wheel that becomes the inner turning wheel, the yaw moment acting on the vehicle becomes smaller and the yaw rate generated in the vehicle becomes smaller. The yawing momentum of the yaw angular acceleration decreases, and the steering characteristic of the vehicle changes in the understeer direction. It should be noted that these changes in the steering characteristics are not limited to the superficial principle that the yaw moment is suppressed or promoted simply by the magnitude of the driving force, but at the same time, the load movement between the left and right wheels during steering turning and the friction circle It goes without saying that it also depends on the change in cornering force depending on the magnitude of the driving force according to the concept.

In this way, in order to change the steering characteristic of the vehicle by controlling the distribution of the driving force to each wheel, for example, in the engagement force control device for the driving force distribution clutch, the yaw rate and the yaw angular acceleration described above are used. It pays attention to the yawing momentum, and from such a meaning, it can be handled as a yawing momentum control device. That is, the yawing momentum (hereinafter also referred to as the actual yawing momentum) such as the yaw rate and the yaw angular acceleration actually occurring in the vehicle can be detected via a sensor such as a yaw moment gyro mounted on the vehicle. On the other hand, as is known, the yawing momentum to be achieved in the vehicle (hereinafter also referred to as the target yawing momentum) has vehicle speed, steering angle or steering angle as variables, and vehicle characteristics including tire characteristics, specifically, cornering power and wheel base. , Tread or a function related to the stability factor related to these or the like. Also,
This target yawing momentum also has vehicle speed, steering angle or turning angle, yawing momentum, etc. as variables, and overshoot and undershoot of steady yawing momentum obtained as a function relating to vehicle characteristics such as stability factor. It can be obtained by performing a delay system operation as a non-first-order delay system. Specifically, this target yawing momentum simply increases with a first-order lag with respect to an increase in the steering angle or the turning angle under a given vehicle speed. Then, feedback control is performed so that the target yawing momentum thus obtained matches the actual yawing momentum actually generated in the vehicle. At this time, in order to realize the target yawing momentum in the actual vehicle, for example, the deviation between the target yawing momentum and the actual yawing momentum is multiplied by a predetermined feedback control gain in consideration of the vehicle specifications and steering characteristics. There is. It should be noted that this feedback control gain is generally set to a constant value that is uniquely determined by vehicle specifications and vehicle characteristics. In addition, the engagement force control device for the present driving force distribution clutch actually controls the calculation of the control force for monitoring the slip state of the wheels and maintaining the slip ratio in the optimum state.

Such a yawing momentum control device is
For example, JP-A-60-16125 previously proposed by the present applicant
Auxiliary steering control device including the four-wheel steering control device described in Japanese Unexamined Patent Application Publication No. 5-53, and Japanese Patent Laid-Open No.
An active suspension and stabilizer control device capable of variable roll stiffness control described in Japanese Patent No. 193332, or the Japanese Patent Application Laid-Open No. 5-1993 previously proposed by the present applicant.
It is being widely applied to a braking force control device or the like for individually controlling the braking force of each vehicle wheel described in Japanese Patent No. 24528.

[0007]

By the way, in calculating the target yawing momentum such as the yaw rate, assuming that the time constant and feedback control gain of the vehicle assumed in the first-order lag system are constant, the actual vehicle It is premised that the actual yawing momentum generated is always delayed with respect to the steering input and is generated in the same manner as the target yawing momentum. However, in the conventional yawing momentum control device, the fact that the vehicle inertia is involved in the actual yawing momentum actually generated in the vehicle is not taken into consideration. That is, for example, when a fast or large steering increase or return is performed, such as a lane change in a medium / high speed running state, there is a first-order delay due to the target yawing momentum tracking control that is increased or decreased in the same manner as the steering input. Even if the generated yawing momentum exceeds the extreme value point of the steering, it remains as the vehicle inertia, and the vehicle behavior becomes difficult to converge.

In order to solve this problem, for example, by simply shortening the delay time of the yawing momentum generated in the vehicle with a first-order lag, the time constant for calculating the target yawing momentum such as the target yaw rate may be set small. Alternatively, it may be considered that the feedback control gain may be set to a large value in order to suppress the yawing momentum generated in the vehicle to the target yawing momentum as much as possible. However, all of these means that as a result, the control amount generated at the control time becomes large, and based on this large control amount, the yawing momentum generated after the shortened delay time is further increased by the vehicle inertia. From the convergence of the vehicle behavior, it is equivalent to the occurrence of a new overshooting yawing momentum, and it is not improved as a result.

Since the above-mentioned problems depend on the magnitude of the steering input, for example, the steering angle is detected as the magnitude of the steering input, and the steering angle is detected.
It is also possible to adjust the response of the yawing momentum feedback control. Then, although the main purpose is different, as a method for adjusting the response of the yawing momentum tracking feedback control by paying attention to such a steering angle, for example, JP-A-3-92482 and 4-2 are disclosed.
There is a yawing momentum control device described in Japanese Patent No. 7667. Among them, the former increases the feedback control gain when the steering angle detection value is small to improve the turning performance of the vehicle, and the latter reduces the feedback control gain when the steering angle detection value is small to reduce the steering angle during straight running. It aims to suppress hypersensitive behavior. However, among these control modes, in the former case, the followability of the yawing motion to disturbance or steering input in a state where the lateral acceleration is large in a steady turn with a large steering angle is reduced, and in the latter case, it is likely that the vehicle is traveling straight ahead. There is a concern that the convergence and tracking of the yawing motion with respect to external disturbances and small steering inputs may deteriorate near the neutral steering position.

The present invention was developed in view of these problems, and a yawing momentum control device for a vehicle capable of improving the convergence of the yawing momentum generated in the vehicle when the fast or large steering is executed. It is intended to provide.

[0011]

A yawing momentum control device for a vehicle according to claim 1 of the present invention is shown in FIG.
As shown in the basic configuration diagram of a steering state detecting means for detecting a steering state given as steering input of the vehicle, and a car Hayaken detecting means for detecting a longitudinal direction vehicle speed of the vehicle, it is actually generated in the vehicle A yawing momentum detecting means for detecting a yawing momentum, a target yawing momentum setting means for setting a target yawing momentum to be achieved in the vehicle based on at least the steering angle detected by the steering state detecting means, and the target yawing momentum setting means. The yawing momentum control of the vehicle provided with feedback control means for performing feedback control using a predetermined feedback control gain so that the yawing momentum detected by the yawing momentum detecting means matches the target yawing momentum set by In the device, the steering state detecting means
Calculate the steering angular velocity based on the steering angle detected in
Calculated by the steering angular velocity calculation means and the steering angular velocity calculation means
To come steering angular velocity which is the the Ru fast der above given, and quick steering state detecting means for detecting that a rapid steering state, when it is detected that the abrupt steering state detecting means is a quick steering state In addition, the target yawing momentum correcting means for correcting the target yawing momentum to a small value is provided.

Further, in the yawing momentum control device for a vehicle according to a second aspect of the present invention, the target yawing momentum correcting means is provided with a filter means for regulating an increase / decrease rate of the target yawing momentum. It is a thing. The yawing momentum control device for a vehicle according to a third aspect of the present invention is characterized in that the target yawing momentum correcting means includes limiter means for preventing an increase or decrease in the target yawing momentum.

Further, in the yawing momentum control device for a vehicle according to a fourth aspect of the present invention, as shown in the basic configuration diagram of FIG. 1, when the target yawing momentum correcting means corrects the target yawing momentum small, A feedback control gain setting means for setting a large feedback control gain of the feedback control means is provided.

[0014]

In the yawing momentum control device for a vehicle according to the first aspect of the present invention, as shown in the basic configuration diagram of FIG. 1, the yawing momentum detecting means includes, for example, a yaw rate sensor or a yaw angular acceleration sensor. The yawing momentum such as the yaw rate and the yaw angular acceleration that is actually occurring is detected. On the other hand, in the steering state detecting means,
For example, the steering angle sensor or the like is used to detect the steering angle, and the target yawing momentum setting means uses at least the steering angle and the vehicle speed detection value to determine a reference yaw rate by a predetermined arithmetic expression or map search. Calculate and set the target yawing momentum such as or yaw angular acceleration. On the other hand, in the abrupt steering state detecting means, for example , the differential value of the steering angle detected by the steering state detecting means is a speed equal to or higher than a predetermined speed, that is, the steering state detection value such as the steering angle is switched back and forth in the increasing direction. when code different between directions, the differential value of the absolute value of the steering state detection value, that is, can the angular velocity of the absolute value of the steering angle is equal to or greater than a predetermined steering angular velocity, by detecting that the quick steering state, At this time, the target yawing momentum correcting means corrects and sets the target yawing momentum small. Then, the feedback control means performs feedback control so that the yawing momentum detected by the vehicle (actual yawing momentum) follows the target yawing momentum set in this way. Of the yaw momentum multiplied by the feedback control gain is set to a predetermined value, for example, “0”, and the actuator provided in the vehicle is driven.
Here, in the present invention, as described above, when the sudden steering state detecting means detects that the vehicle is in the rapid steering state, in order to correct the target yawing momentum small, for example, a lane change in a medium / high speed traveling state. not fast like etc.
The steering time with return Switching Operation widening and cutting, the target yawing momentum itself such as the yaw rate and the yaw angular acceleration decreases, when the follow-up control to the small target yawing momentum is performed by the feedback control means,
The actual yawing momentum generated in the vehicle after this is reduced, and the vehicle inertia remaining beyond the extreme point of the steering input is reduced, so that the convergence of the vehicle behavior is improved. Since the steering angle or the steering angular velocity has the increasing direction and the returning direction, it is possible to set different predetermined steering angular velocity values in the respective directions .

Further, in the yawing momentum control device for a vehicle according to a second aspect of the present invention, since the target yawing momentum correcting means is provided with a filter means for restricting an increasing / decreasing rate of the target yawing momentum, for example, If the increase / decrease rate restriction of the target yaw momentum by the filter means is set to simply reduce the increase / decrease rate of the target yawing momentum set by the target yawing momentum setting means, the steering state detection value performed by the target yawing momentum setting means is set. That is, it is possible to reduce the target yawing momentum while reflecting the increasing / decreasing direction of the target yawing momentum according to the increase / decrease of the steering input. By this, the convergence behavior of the vehicle behavior can be achieved while achieving the yawing motion reflecting the driver's intention. Can be improved.

Further, in the yawing momentum control device for a vehicle according to a third aspect of the present invention, the target yawing momentum correcting means is provided with limiter means for preventing increase or decrease of the target yawing momentum. Steering state detection value performed by yawing momentum setting means,
That is, if the increase / decrease in the target yawing momentum in accordance with the increase / decrease in the steering input does not need to be increased / decreased, the correction can be made so as to prevent the increase / decrease in the target yawing momentum. It is possible to prevent the target yawing momentum from increasing or decreasing unnecessarily due to the steering input by, and if this feedback control means performs follow-up control, it is possible to prevent the actual yawing momentum that appears in the vehicle from becoming excessive. Thus, the convergence of vehicle behavior can be improved.

Further, in the yawing momentum control device for a vehicle according to a fourth aspect of the present invention, as shown in the basic configuration diagram of FIG. 1, when the target yawing momentum correcting means corrects the target yawing momentum small, Since the feedback control gain used in the feedback control means is set to be large in the feedback control gain setting means, for example, when the reference target yawing momentum is increased by the filter means, the increase rate is reduced to a target value. When the yawing momentum is set smaller than the reference value and its feedback control gain is set to a slightly larger value, and when the reference target yawing momentum is decreased by the limiter means, the target yawing momentum increased until then and the target yawing momentum is smaller than the reference value. Yawing momentum And sets so as not to decrease,
By setting the feedback control gain to a larger value, the actual yawing momentum, which is controlled following the target yawing momentum with the increase of the steering input, increases to a certain extent to improve the turning ability of the vehicle and to improve the steering performance. As the input decreases, the followability of the actual yawing momentum with respect to the target yawing momentum increases and the stability improves, so that the convergence of the vehicle behavior improves while achieving the required yawing motion. On the contrary, if the feedback control gain is set to a comparatively small value during normal turning, a comparatively large actual yawing observed in the existing vehicle characteristics with a comparatively slow steering input or steering condition. The amount of exercise can be expressed slowly, and favorable turning characteristics can be obtained from the riding comfort such as a feeling of vehicle weight.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle yaw momentum control device of the present invention will be described below with reference to the accompanying drawings. 2 to 7 show a first embodiment in which the yawing momentum control device for a vehicle according to the present invention is applied to a driving force distribution control device for the rear left and right wheels. In this embodiment, a case where the present invention is applied to a differential limiting device of a rear wheel drive vehicle driving force left / right distribution control device based on an FR (front engine / rear drive) system will be described.

In FIG. 2, the rotational drive source, that is, the rotational drive force of the engine 1 as an engine is transmitted to a transmission 2 via a clutch (not shown), and is shifted at a gear ratio selected by the transmission 2, and its output is output. The differential case 11 which is transmitted from the propeller shaft 3 to the ring gear 5 via the drive gear 4 and is fixed to the ring gear 5 is rotated. A differential gear 12 composed of two differential pinions 12a and two left and right side gears 12b is provided in the differential case 11. Each side gear 12b is rotated by the rotation of the differential case 11, and each side gear 12b is rotated. The left and right drive shafts 8L and 8R, which are connected to each other via universal joints, are rotated to rotate the left and right rear wheels 6L and 6R.
The driving force is transmitted to.

On the other hand, the front left and right wheels 9L, 9R are non-driving wheels, so-called driven wheels, and the operation amount of the steering wheel 10 is converted by an existing steering mechanism to steer the front left and right wheels 9L, 9R. Here, the operation amount of the steering wheel 10 is defined as a steering angle θ, and the steering angles of the front left and right wheels 9L, 9R are determined with respect to the steering angle θ via the gear ratio N of the steering mechanism. .

By the way, multi-plate type clutches 7L and 7R are interposed between the differential case 11 and the left and right drive shafts 8L and 8R, and the drive-driven clutch plates of the clutches 7L and 7R are pressed. As a result, the frictional force between the plates is reduced by the differential case 11 and the drive shafts 8L, 8R.
Regulates relative rotation with. That is, each clutch 7L, 7R
Since the frictional force between the plates increases as the pressing force of is increased, the relative rotation between the differential case 11 and the drive shafts 8L and 8R is strongly regulated, and this relative rotation regulation force is the field differential limiting torque of this embodiment. Corresponds to. In this embodiment, among the clutch plates of each of the multi-plate clutches 7L and 7R, the drive clutch plate on the side of the differential case 11 is fixed, and the driven clutch plate on the side of the drive shafts 8L and 8R is a coupling body 17L, which connects them. It is arranged so as to be movable in the axial direction of the side gear 12b via 17R.

Then, each of the multi-plate clutches 7L, 7R
Of each of the moving side driven clutch plates of the springs 19L and 19 for applying the initial setting differential limiting torque T _0.
R is pressed inward through the left and right connecting bodies 17L, 17R and the left and right pressing rods 16L, 16R. The pressing force of the springs 19L and 19R is equal to the initial setting differential limiting torque T ₀ before the differential limiting torque is controlled by the differential limiting torque control means described later or when the operation control torque control means fails. Left and right sum (2 x T
₀ ) is set so as not to give an uncomfortable feeling due to the braking phenomenon when the vehicle is turning at a slight speed.

Further, each of the left and right pressing rods 16L and 16R changes the pressing force of the multi-plate clutches 7L and 7R to change the differential limiting torque.
5L and 15R are individually connected. The pistons 13L, 13R in the fluid pressure cylinders 15L, 15R are actuated by increasing the cylinder stroke control fluid pressure (hereinafter, also simply referred to as cylinder control pressure) P _C from an actuator unit 20 described later, to the multi-disc clutch 7L, 7
When the driven clutch plate of R is moved inward to press it toward the drive clutch plate and the cylinder control pressure P _S is reduced, the return springs 14L, 1
The 4R moves the clutch plates in a direction of separating them. However, the elastic force of the return springs 14L and 14R, that is, the elastic coefficient, is set so as to return the pistons 13L and 13R to the original position, and the differential limiting torque T by the multi-plate clutches 7L and 7R is Simply, it depends only on the cylinder control pressure P _S , and both of them depend on the initial setting differential limiting torque T by the springs 19L and 19R.
It is assumed that they have a linear relationship with each other as shown in FIG. 4A with ₀ as an initial value, and the maximum differential limiting torque T _MAX is saturated at the maximum predetermined value P _S1 of the cylinder control pressure P _S , that is, the rear left and right drives. Shafts 8L and 8R and propeller shaft 3
Let and be rigid.

As shown in FIG. 3, the actuator 20 includes a pump 22 for pressurizing and discharging the working fluid in the reservoir 21, a check valve 23 for rectifying the discharge fluid pressure from the pump 22, and the discharge fluid. An accumulator 24 for accumulating pressure and each cylinder control pressure P _{SL for} the left and right fluid pressure cylinders 15L, 15R using this fluid pressure.
Two proportional solenoid valves 25L, 2 for individually adjusting and controlling P _SR
And 5R. These two proportional solenoid valves 25L, 2
In both 5R, the pump port is cut off and the output port communicates with the return port at the normal first switching position shown by the return spring, and the proportional electromagnetic solenoid 26
When the second switching position is reached by the excitation of L and 26R, the pump port and the output port are communicated with each other and the return port is cut off. As a matter of course, the pump port is connected to the pump 22 and the return port is returned. The port is connected to the reservoir and the output port is each proportional solenoid valve 25.
It is connected to L and 25R. Therefore, the proportional solenoid 26L, exciting force of 26R increases, i.e. the proportional electromagnetic solenoid 26L, the drive current signal CS _L to 26R, the current value of the CS _R increases, the proportional solenoid valves 25L, the output of the 25R the output pressure from the port, i.e. the respective hydraulic cylinders 15L, cylinder control pressure P _S to 15R
Grows larger. Therefore, in this embodiment, the correlation between the two is set to the linear characteristic as shown in FIG. 4b, and accordingly, the drive current signals CS _L , C are determined from the correlation with the differential limiting torque shown in FIG. 4a.
S _R of the target current value S _L, by adjusting control S _R, the multiplate clutch 7L, adjusting and controlling the differential limiting torque T according 7R. The rotation output of the pump 22 is controlled by the drive current signal CS _M from the control unit 40 according to a calculation process (not shown) based on a detection signal of a pressure switch (not shown). Further, in this embodiment, at the time of so-called failure in which a failure occurs in each sensor, control unit 40 and actuator unit 20 described later, each of the proportional solenoid valves 25L,
5R proportional electromagnetic solenoid 26L, to 26R drive current signal CS _L, the current value of the CS _R and to "0",
As a result, the proportional solenoid valves 25L, 25R return to the normal first switching position, so that the fluid pressure cylinders 15L, 25L
The fluid pressure of 15R returns and becomes equal to or almost equal to the atmospheric pressure, and the differential limiting torque T by the multi-plate clutches 7L and 7R becomes the initial setting differential limiting torque T ₀ ,
Therefore, the rear wheel differential functions as a limited slip differential having only this initial setting differential limiting torque T ₀ .

Here, the definition of the transmission driving force ratio N, which will be described in detail later, will be briefly described. That is, as shown in Figure 4b, the respective proportional solenoid valves 25L, the proportional electromagnetic solenoid 26L of 25R, the drive current signal CS _L to 26R, CS _R of the target current value S _L, S _R is the maximum predetermined value CS _L1, At CS _R1 , the cylinder control pressures P _SL and P _SR to the fluid pressure cylinders 15L and 15R become maximum predetermined values P _SL1 and P _SR1. Therefore, the differential limiting torque T by the multi-plate clutches 7L and 7R is 4a, the maximum differential limiting torque T _MAX
Therefore, the rear left and right drive shafts 8L, 8R and the propeller shaft 3 rotate in a rigid state and co-rotate with each other, so that the rotational driving force ratio transmitted between them is "1" or almost "1". Become. Then, the drive current signal CS _L from this state, CS _R of current values S _L, according to the S _R becomes smaller, the fluid pressure cylinder 15L, cylinder control pressure P _SL to 15R, becomes small P _SR, hence multi The differential limiting torque T due to the plate clutches 7L and 7R is gradually reduced to gradually allow the relative rotation between the differential case 11 and the side gears 12b. The relative rotation becomes possible, and the ratio of the transmission rotation driving force between them becomes gradually smaller. If this is taken to be the transmission driving force ratio N from the propeller shaft 3 to each of the rear left and right wheels 6L, 6R, this transmission driving force ratio N will be used as the rear left and right wheels 6L, 6R.
By appropriately setting between 6R, the yaw moment generated in the vehicle can be promoted or suppressed, so that the target yaw rate ψ ^'* corresponding to the steering angle and the vehicle speed is actually generated in the vehicle. In the yaw rate follow-up control, which will be described later, for matching the actual yaw rate ψ ′ with each other, the transmission driving force ratio N is calculated and set as a control amount.

On the other hand, returning to FIG. 2, the rear left and right wheel drive force distribution
The minute control device detects the steering angle of the steering wheel 10.
Detects the steering angle sensor 41 and the vehicle speed in the front-back direction
Vehicle speed sensor 42 and the yaw that is actually occurring in the vehicle.
The yaw rate sensor that detects the rate as yawing momentum
Sensor 43 and lateral acceleration that detects the lateral acceleration generated in the vehicle
The degree sensor 44 and the amount of depression of the accelerator pedal 39, that is,
An accelerator opening sensor 45 for detecting the accelerator opening, and
Rear left / right wheel speed sensors 46RL, 46R for detecting left / right wheel speeds
Based on R and the detection signals from these sensors,
Motion current signal CS _L, CS_RTo output the fluid pressure cylinder
Cylinder control pressure P to cylinders 15L and 15R _SL, P_SRControl
And a control unit 40 for controlling.

The steering angle sensor 41 is a steering angle detection value θ which is a voltage output which corresponds to the steering angle of the steering wheel 10 and has a positive value when the steering wheel 10 is turned to the right and a negative value when the steering wheel 10 is turned to the left. Is output to the control unit 40. Further, the vehicle speed sensor 42
Outputs to the control unit 40 a vehicle speed detection value V that is a voltage output that increases in the positive direction according to the vehicle speed in front of the vehicle. Further, the yaw rate sensor 43 supplies to the control unit 40 an actual yaw rate detection value ψ ′ that is proportional to the actual yaw rate actually occurring in the vehicle and has a voltage output that is a positive value in the right turn and a negative value in the left turn. Output. The lateral acceleration sensor 44 controls the lateral acceleration detection value Y _G, which is proportional to the lateral acceleration actually generated in the vehicle and has a voltage output that is a positive value in the right turn and a negative value in the left turn. Output to 40. Further, the accelerator opening sensor 45 outputs to the control unit 40 an accelerator opening detection value Acc represented by 0/8 to 8/8, which is a digital value corresponding to the amount of depression of the accelerator pedal 39. Further, the rear left and right wheel speed sensors 46RL, 46RR
Is a rear left / right wheel speed detection value Vw _RL , Vw _RR consisting of a sine wave voltage signal having a frequency corresponding to the wheel speed of each of the rear left / right wheels 6L, 6R.
Is output to the control unit 40.

As shown in FIG. 3, the control unit 40 supplies the microcomputer 51 and the drive current signals CS _L and CS _R to each proportional solenoid valve 25.
Drive circuits 53L and 53R for driving L and 25R, and a drive circuit 54 for supplying the drive current signal CS _M to drive the pump 22 are provided. Further, the microcomputer 44 has an F / V conversion function for reading the detection signals from the respective sensors as respective detection values, a waveform shaping function, and an A / V conversion function.
Input interface circuit 44a having D conversion function and the like
And a processing unit 44b including a microprocessor unit (MPU) and a storage device 44 such as a ROM and a RAM.
c and an output interface circuit 44d having a D / A conversion function for outputting target current value control signals S _L and S _R according to the differential limiting torque T obtained by the arithmetic processing unit 44b. There is. This control unit 40
The microcomputer 44 of FIG. 7 will be described in detail later.
The target yaw rate ψ ^'* to be achieved in the vehicle is calculated and set based on the steering angle detection value θ and the vehicle speed detection value V according to the calculation process of the above, and the feedback control gain K used in the calculation process of FIG. ₂ is calculated and set, and according to the calculation process of FIG. 5 to be described later, the slip speed corresponding to the turning outer wheel of the rear left and right wheels 6L and 6R, which are the drive wheels, is calculated by the individual calculation process (not shown) which is a minor program thereof. To calculate and set the clutch torque T _1j (j = LorR) by each of the multi-plate clutches 7L and 7R for matching the target slip speed corresponding to the detected accelerator opening value Acc of the accelerator pedal 39 with In order to generate the desired tack-in when the accelerator is turned off by a separate calculation process (not shown) that is a program, each of the multi-plate type Pitch 7L, the tuck-in torque T _2j corresponding to the lateral acceleration detection value Y _G of the vehicle and the vehicle speed detection value V calculated set by 7R, whereas basically the target yaw rate [psi ^'* and the actual yaw rate detected value and the yaw angular acceleration difference Δψ of these differentiating target yaw angular acceleration ψ obtained by ^"* and the actual yaw angular acceleration ^ψ" and ^'yaw rate difference Δψ of ^the' ψ
^"It is calculated, and the yaw angular acceleration difference [Delta] ^[phi]" the yaw rate difference with a preset value obtained by multiplying the differential control gain K ₃ was the Δ
by adding the [psi ^', further configured feedback control is also a proportional control gain gain K by the arithmetic processing of FIG. 7
Calculating the inner ring transmission drive force ratio N _i from the inverse of a value obtained by multiplying the ₂ "1" to a smaller turning inner to the inner ring transmits the driving force ratio N _i and is set to a relatively "1" the turning outer wheel the outer ring transmission drive force ratio N _o, by multiplying the said clutch torque T _1j and tuck-in torque T _2j calculates the differential limiting torque T _j, the target current value control sufficient to achieve this differential limiting torque T _j The signal S _j is output to the proportional solenoids 26L and 26R of the proportional solenoid valves 25L and 25R.

The drive circuits 53L and 53R output the target current value control signals S _L and S _R output from the microcomputer 44 to the drive current signals to the proportional solenoids 26L and 26R of the proportional solenoid valves 25L and 25R. C
It is for converting and outputting to S _L and _{C R} , and as shown in FIG. 4b, the target current value control signals S _L and S _R
Is converted into linear drive current signals CS _L and CS _R and output.

Next, the basic yaw rate (yaw momentum) feedback PD (proportional derivative) executed by the microcomputer of the control unit of this embodiment.
The control calculation process will be described with reference to the flowchart of FIG. This calculation process is executed by a timer interrupt at every predetermined sampling time ΔT (for example, 10 msec.). The calculation setting of the turning outer wheel slip speed countermeasure clutch torque _T1j in step S105 described later is to execute the arithmetic processing described in JP-A-3-31030 previously proposed by the applicant as a minor program. Done in
Detailed contents thereof will not be described in detail here with reference to the publication. Further, the calculation setting of the tack-in countermeasure torque T _2j in step S106 described later is performed by executing the arithmetic processing described in JP-A-3-31030 previously proposed by the applicant as a minor program, Detailed contents thereof will not be described in detail here with reference to the publication. Also, step S107 described later.
The current value ψ ^'* _(n) of the target yaw rate calculated and set by
It is assumed that a positive value is always set in accordance with the minor program of FIG. 7 described later regardless of the steering or turning direction. However, the actual yaw rate ψ ′ detected as described above has a positive or negative value depending on the turning direction. , The target yaw rate current value ψ ^'* _(n) is reset to a positive or negative value according to the turning direction. Further, the information updated and stored in the storage device 44c of the microcomputer 44 does not have a special information communication step in the present arithmetic processing, but a buffer of the arithmetic processing device 44b is provided through a communication path such as a data bus (not shown). It is assumed that they are in contact with the etc. at any time.

In this calculation process, first, step S101.
Then, the steering angle detection value (hereinafter also simply referred to as the steering angle) θ detected by the steering angle sensor 41 is read. Then step S
In step 102, the vehicle speed detection value (hereinafter also simply referred to as vehicle speed) V detected by the vehicle speed sensor 42 and the current yaw rate value ψ ′ _(n) detected by the yaw rate sensor 43 are read.

Next, the routine proceeds to step S103, where an accelerator opening detection value (hereinafter also simply referred to as accelerator opening) Acc detected by the accelerator opening sensor 45, and rear left and right wheel speed sensors 46RL, 46RR are detected. Rear left / right wheel speed detection value (hereinafter also simply referred to as rear left / right wheel speed) Vw _Rj (j = L
orR). Next, in step S104, the lateral acceleration detection value (hereinafter also simply referred to as lateral acceleration) Y _G detected by the lateral acceleration sensor 44 is read.

Next, in step S105, the accelerator opening Acc and the rear left and right wheel speeds Vw _Rj read in step S103 are used to determine, for example, the above-mentioned JP-A-3-310.
By executing the arithmetic processing described in Japanese Patent No. 30 as a minor program, the turning outer wheel slip speed countermeasure clutch torque T _1j is calculated and set. Next in step S10
6, the accelerator opening Acc read in step S103, the vehicle speed V read in step S102, and the lateral acceleration Y _G read in step S104.
By using, for example, the arithmetic processing described in JP-A-3-31030 is executed as a minor program, the tack-in countermeasure torque T _2j is calculated and set.

Next, in step S107, the current value ψ ^'* _(n) of the target yaw rate is calculated and set according to the calculation process by the minor program of FIG. In this embodiment, the feedback control gain K ₂ which is also the proportional coefficient of the yaw rate feedback PD control is set in step S107, but the setting of the feedback control gain K ₂ is not always an essential requirement of the present invention.

Next, in step S108, it is determined whether or not the steering angle θ read in step S101 is "0" or more, that is, whether the vehicle is turning left or not.
Is greater than or equal to "0" and it is considered to be a right turn, the process proceeds to step S109. If not, that is, if it is considered to be a left turn, the process proceeds to step S110.

In step S109, the turning inner wheel is shown.
Set the subscript i to the subscript R that indicates the rear right wheel, and indicate the outer turning wheel.
Set the subscript o to the subscript L that indicates the left rear wheel, and then step
The process moves to S111. In the step S111, right turn
Current value of target yaw rate ψ^'* _(n)Is before
The target yaw of the positive value calculated and set in step S107.
Current value ψ^'* _(n)This is the target yaw
Current rate ψ^'* _(n)After setting to step S11
Move to 2.

On the other hand, in step S110,
Set the subscript i indicating the wheel to the subscript L indicating the rear left wheel, and
Set the subscript o indicating the ring to the subscript R indicating the rear right wheel, and then
Then, the process proceeds to step S113. In step S113
Is the current value of the target yaw rate ψ^'*
_(n)Is the positive value calculated and set in step S107.
Current value of target yaw rate ψ^'* _(n)Change to a negative value
Target yaw rate changed to this negative value because it is necessary
This time value of ψ^'* _(n)Is the target yaw rate value ψ^'* _(n)When
After setting, the process proceeds to step S112.

In step S112, the current yaw rate value ψ ' _(n) read in step S102 and the previous value ψ' _{(n-1) of the} actual yaw rate updated and stored in the storage device 44c and a predetermined value. The actual yaw angular acceleration ψ ″ is calculated and set according to the following formula 1 using the sampling time ΔT. Note that the actual yaw angular acceleration ψ ″ is calculated and set without depending on the calculation of the following formula 1 or the like. It can also be obtained by a differential operation process such as a high-pass filter process set to the off frequency.

Ψ ″ = (ψ ′ _(n−1) −ψ ′ _(n) ) / ΔT (1) Next, the process proceeds to step S114, and the step S11 is performed.
1 or the current value ψ ^{′ *} _{(n) of} the target yaw rate set in step S113, the previous value ψ ^{′ *} _{(n−1) of the} target yaw rate updated and stored in the storage device 44c, and the predetermined sampling time ΔT are used. Then, the target yaw angular acceleration ψ ^"* is calculated and set according to the following two equations. Note that the calculation setting of the target yaw angular acceleration ψ ^{" *} does not depend on the calculation of the following two equations.
For example, it can be obtained by a differential operation such as a high-pass filtering process set to an appropriate cutoff frequency.

Ψ ^"* = (ψ ^'* _(n-1) -ψ ^{' *} _(n) ) / ΔT (2) Then, the process proceeds to step S115, and the step S11 is performed.
Calculating a yaw rate difference [Delta] [phi] 'according to the following equation 3 using 1 or current value [psi target yaw rate that has been set in step S113 ^{the' *} _(n) and the present value of the actual yaw rate which is read in step S102 ψ _'(n) Set.

Δψ ′ = | ψ ^{′ *} _(n) −ψ ′ _(n) | ... (3) Then, the process proceeds to step S116, and the step S11 is performed.
Using the actual yaw angular acceleration ψ ″ calculated and set in step 2 and the target yaw angular acceleration ψ ^{″ *} calculated and set in step S114, the yaw angular acceleration difference Δψ ″ is calculated and set according to the following four equations. Δψ ″ = | ψ ^"* -ψ" | ... (4) Then, the process proceeds to step S117, and the step S11 is performed.
5, the yaw rate difference Δψ ′ calculated and set, a predetermined feedback control gain K ₂ which also serves as a proportional coefficient, and the yaw angular acceleration difference Δ calculated and set in step S116.
The inner ring transmission drive force ratio N _i is calculated set according to the following equation 5 using [psi "and derivative K _3.

N _i = 1 / (K ₂ (Δψ ′ + K ₃ · Δψ ″)) (5) Next, the process proceeds to step S118, where the subscript i indicating the turning inner wheel is the subscript R indicating the rear right wheel. If the subscript i indicating the turning inner wheel is the subscript R indicating the rear right wheel, the process proceeds to step S119. If not, that is, the subscript i indicating the turning inner wheel indicates the rear left wheel. If the suffix is L, the process proceeds to step S120.

In step S119, the left wheel transmission drive is performed.
Power ratio N_LIs set to "1" and the right wheel transmission drive force ratio N
_RIs the inner ring transmission driving force calculated in step S117.
Ratio N _iAfter that, the process proceeds to step S121. Previous
In step S120, the right wheel transmission driving force ratio N_RTo
Set to "1" and the left wheel transmission drive force ratio N_LThe above
Inner wheel transmission driving force ratio N calculated in step S117 _iSet up
After being determined, the process proceeds to step S121.

In step S121, the slip speed countermeasure clutch torque T _1j calculated and set in step S105, the tack-in countermeasure torque T _2j calculated and set in step S106, and each wheel transmission set in step S119 or step S120. Driving force ratio N _j (j = Lor
R) is used to calculate and set the differential limiting torque T _j to the rear left and right wheels 6L, 6R according to the following six equations.

T _j = N _j (T _1j + T _2j ) ... (6) Then, the process proceeds to step S 122, and the step S 12 is performed.
Proportional electromagnetic solenoid 2 of each proportional electromagnetic valve 25L, 25R sufficient to achieve the differential limiting torque T _j calculated and set in 1.
The target current value S _j for 6L and 26R is set, for example, according to the control map of FIG.

Next, in step S123, the target current value S _j set in step S122 is set to the proportional electromagnetic solenoid 26 of each proportional electromagnetic valve 25L, 25R.
It is output as a control signal to L and 26R. Next, the routine proceeds to step S124, where the current yaw rate current value ψ ′ is
_(n) is the previous value of the actual yaw rate ψ ' _(n-1) , and the current value of the target yaw rate ψ ^{' *} _(n) is the previous value of the target yaw rate ψ ^'* _(n-1). After updating and storing in a predetermined storage area of 44c, the program returns to the main program.

According to the calculation process shown in FIG. 5, for example, the tack-in countermeasure torque T _2j calculated and set in step S106 is "0", and the inner wheel transmission drive force ratio N _i calculated and set in step S117 is set. Assuming "1", the slip speed countermeasure clutch torque _T1j calculated and set in the step S105 depends on the slip speed corresponding to the accelerator opening Acc while allowing the difference between the inner and outer wheel speeds of the turning, that is, the driving force to be transmitted. The differential limit torque T _j is set to such a value that the traction loss is allowed, and as a result, the slip ratios of the rear left and right wheels 6L and 6R do not exceed these allowable slip ratios. A target current value control signal S _j sufficient to achieve T _j is output. Therefore, since the target current value control signal S _j and the linear drive current signal CS _j are supplied from the drive circuit 53j to the proportional electromagnetic solenoid 26j of the proportional solenoid valve 25j, the fluid pressure of each of the left and right multi-plate clutches 7L, 7R. Cylinder 15L, 15
The cylinder control pressure P _Sj to the R causes the left and right multi-plate clutches 7L and 7R to generate the slip speed countermeasure clutch torque T _1j , so that the slip ratios of the rear left and right wheels 6L and 6R have the above-mentioned allowable slip ratios. It is controlled to the extent that it does not exceed.
Therefore, even if an excessive slip occurs on the left and right wheels 6L and 6R after driving due to a change in the road surface friction coefficient state (simply referred to as the road surface μ), an optimum slip is achieved by the slip speed countermeasure clutch torque T _1j. , So-called traction control is executed.

Further, the calculation setting is made in step S105.
Sliding speed countermeasure clutch torque T _1jIs “0” and
Inner wheel transmission driving force ratio calculated and set in step S117
N_iIs “1”, the calculation is performed in step S106.
Tuck-in countermeasure torque T that is set_2jIs turning
Lateral acceleration Y_GWhen the accelerator is off while the vehicle is operating
In addition, the cornering force of the rear wheels that recovers rapidly
Steering characteristics in the understeer direction that are strong against the vehicle
It is a value that does not change, and as a result each rear left and right wheel
Cornering force of 6L and 6R does not increase sharply
Limited differential torque T_jIs calculated and set, this differential
Limit torque T_jTarget current value control signal S sufficient to achieve
_jIs output. Therefore, this target current value control signal S_j
And linear drive current signal CS_jFrom the drive circuit 53j
Example is supplied to the proportional solenoid 26j of solenoid valve 25j
Therefore, the fluid pressure of each of the left and right multi-plate clutches 7L and 7R is
Cylinder control pressure P to the cylinders 15L and 15R_SjIs this
The tuck-in pair is attached to each of the left and right multi-plate clutches 7L and 7R.
Measure torque T_2jThe rear left and right wheels 6L, 6
The cornering force of R is the strong understeer direction mentioned above.
It is controlled to the extent that it does not become.

On the other hand, the absolute value of the steering angle | θ |
Immediately below the approximate straight running threshold set to a small value, immediately
The absolute value of the current value of the target yaw rate | ψ^'* _(n)Is almost
As a result of zero steering input at the same time, the actual yaw
Absolute value of the current value of _(n)To a relatively small value
If the yaw rate convergence threshold is less than or equal to
Is the slip velocity pair calculated and set in step S105.
Measure clutch torque T_1jAnd calculated in step S106
Tack-in countermeasure torque T that is set_2jIs a constant value
And calculated in steps S117 to S119.
Inner / outer wheel transmission drive ratio N set_i, N_oIs “1” or
It becomes almost "1", and as a result, the rear left and right wheels 6L, 6R
Differential limiting torque T_jAre equal or nearly equal values?
The differential limiting torque T_jTarget current sufficient to achieve
Value control signal S_jIs output. Therefore, this target current value
Control signal S_jAnd linear drive current signal CS_jDrive circuit
53j to proportional solenoid solenoid 26 of proportional solenoid valve 25j
j is supplied to each of the left and right multi-plate clutches 7L,
Cylinder control for 7R fluid pressure cylinders 15L, 15R
Pressure P_SjIs equivalent to the left and right multi-plate clutches 7L and 7R
Differential limiting torque T_jCausing an approximate straight line
For vehicle disturbances such as road surface irregularities and crosswinds,
Tearing characteristics become understeer direction and running stability
Is improved.

On the other hand, when the absolute value of the steering angle | θ | becomes larger than the approximate straight traveling threshold value set to a relatively small value, the absolute value of the present value of the target yaw rate | ψ ^'* _(n) | in step S107. Occurs, and the yaw rate feedback control is started. Here, when the current positive value of the target yaw rate ψ ^'* _(n) is set in step S107, it is matched with the sign according to the turning direction in step S108 to step S111 or step S113. At the same time, the turning inner wheel and the turning outer wheel are set in step S119 or step S110. In step S120 from step S112 and then, transmits the driving force ratio N _o corresponds to the turning outer wheel is set to "1", transmission drive force ratio N _i corresponding to the turning inner wheel is the yaw rate difference [Delta] [phi] 'and the yaw angle according to the equation 5 It is set to a value smaller than "1" according to the acceleration difference Δψ ", and in step S121, each differential limiting torque T _j to the turning inner and outer wheels sufficient for following the yaw rate is calculated and set.

[0051] Thus, the subsequent target current value S _j corresponding to the respective differential limiting torque T _j calculated set at step S122, the target current value S _j each drive circuit 46L, when the output as a control signal to 46R , Each drive circuit 46L, 46R
Its target current value control signal S _j drive current signals corresponding to the CS _L, CS _R each proportional solenoid valves 25L, the proportional electromagnetic solenoid 26L of 25R, is the differential limiting torque T _j is output to 26R achieved from Therefore, as a result, the feedback PD control for the current value ψ ^{′ *} _(n) of the target yaw rate is executed. Here, the yaw angular acceleration obtained by differentiating the yaw rate as is known is
The phase is advanced by about 90 ° in the complex plane. Conversely, the yaw rate has a phase of about 90 ° with respect to the yaw angular acceleration.
You're late. Therefore, the yaw angular acceleration difference Δψ ″ used to calculate the inner wheel transmission driving force ratio N _i enhances the control responsiveness, and the yaw rate difference Δψ ′ reduces the control responsiveness, which is desirable for the vehicle. Depending on the response of the control, for example, a proportional coefficient (also used as a feedback control gain as will be described later) K ₂ multiplied by the yaw rate difference Δψ ′ is properly set, and the yaw angular acceleration difference Δψ ″ The differential coefficient (which becomes the feedback control differential gain as a whole) K ₃ synergistic with the feedback control gain K ₂ may be set in advance.

As described above, during the normal turning turning, the present value ψ ^'* _{(n) of} the appropriate target yaw rate corresponding to the steering angle θ and the vehicle speed V is set as will be described later, and this is set for turning. Current yaw rate ψ'of the actual yaw rate occurring in the vehicle with respect to the absolute value of the current yaw rate ψ ^'* _(n) of the target yaw rate matched to the direction
_When the absolute value of _(n) is small, or when the actual yaw angular acceleration ψ ”generated by the vehicle is small with respect to the absolute value of the target yaw angular acceleration ψ ^{" * "} that is further in phase. Therefore, it is necessary to accelerate the yawing motion by promoting the yaw moment. In such a case, the inner wheel transmission driving force ratio N _i calculated and set by the equation 5 in step S117 is set to a smaller value. Become. Therefore, the transmission driving force ratio N _i of the turning inner wheel due to the differential limiting torque T _j achieved by the above-described feedback control becomes correspondingly smaller than the transmission driving force ratio N _o (= 1) of the turning outer wheel. Therefore, the driving force of any of the driven left and right wheels 6L or 6R corresponding to the turning outer wheel becomes relatively large with respect to any of the driven right and left wheels 6R or 6L corresponding to the turning inner wheel, as described above. The yaw moment is promoted, the actual yaw rate and the actual yaw angular acceleration increase, and the yawing motion is accelerated. On the contrary, the current yaw rate ψ ^{′ of the} actual yaw rate occurring in the vehicle with respect to the absolute value of the current yaw rate ψ ^{′ *} _(n) of the target yaw rate.
_When the absolute value of _(n) is large, or when the actual yaw angular acceleration ψ ”that is occurring in the vehicle is large with respect to the absolute value of the target yaw angular acceleration ψ ^{“ * ”} that is further in phase. In order to reduce the yawing moment by suppressing the yaw moment, in such a case, the inner wheel transmission driving force ratio N _i calculated and set by the equation 5 in step S117 is set to a larger value. Become. Therefore, the transmission driving force ratio N _i of the turning inner wheel due to the differential limiting torque T _j achieved by the above-described feedback control becomes correspondingly larger than the transmission driving force ratio N _o (= 1) of the turning outer wheel. Therefore, the driving force of one of the driven left and right wheels 6L or 6R corresponding to the turning outer wheel becomes relatively smaller than that of any of the driven right and left wheels 6R or 6L corresponding to the turning inner wheel, as described above. The yaw moment is suppressed, the actual yaw rate and the actual yaw angular acceleration are reduced, and the yawing motion is decelerated.

Further, in the present embodiment, the deviation between the current yaw rate ψ ' _{(n) of the} actual yaw rate and the current yaw value ψ ^{' *} _(n) of the target yaw rate, which are generally considered to occur with a first-order lag with respect to the steering input, that is, Even when the steering direction is switched such that the polarity of the yaw rate difference Δψ ′ changes, the transfer driving force ratio N _i of the turning inner wheel that has been switched is calculated and set using the yaw angular acceleration difference Δψ ″ whose phase is ahead of this. Therefore, by appropriately setting the differential coefficient K ₃ as described above, it is possible to relatively quickly match the direction of the yawing motion to be expressed with the turning or steering direction.

Then, next, the basic principle of setting the present value ψ ^'* _(n) of the target yaw rate calculated and set in step S107 of the calculation process of FIG. 5 and the setting of the feedback control gain K _{2 which} is also set The basic principle will be described. First, before the target yaw rate ψ ^'* and the target yaw angular acceleration ψ ^"* that are set as the target yaw momentum, the two reference calculation methods for the reference target yaw rate ψ ^{' *} ₀ as the reference target yaw momentum are explained. To do.

First, the reference target yaw rate ψ ^'*
As described above, ₀ is given by the following eight equations with the vehicle speed V and the steering angle θ as variables according to _the known vehicle motion equation and the vehicle specifications as coefficients. ψ ^'* = V / R R = K _S · L / tan (θ / N) (8) where R: turning radius, L: wheel base, N: steering gear ratio. Further, K _S is a stability factor, and this stability factor K _S is a coefficient showing the vehicle behavior stability that appears in turning characteristics, etc. Generally, the larger the stability factor K _{S, the} more the steering characteristics tend to be understeer. To be done.

The reference target yaw rate ψ ^'* ₀ can also be calculated using the steady-state yaw rate H ₀ . Generally, the steady-state yaw rate H ₀ is given by the following equation 9 using the vehicle speed V and the steering angle θ as variables and the stability factor K _S , the steering gear ratio N and the wheel base L as coefficients. H ₀ = V / (L (1 + K _S V ² ))  (θ / N) (9) Then, the reference target yaw rate ψ ^'* ₀ is the first-order lag time constant τ with respect to this steady-state yaw rate H ₀ . It is also known that it can be obtained by performing a first-order lag system calculation using

Ψ ^'* ₀ = H ₀ / (1 + τs) (10) However, s represents a Laplace operator (Laplacian). Here, it is of course possible to calculate the reference target yaw rate ψ ^'* ₀ according to the above equations 8 or 9 and 10, but it is difficult to avoid that the calculation load becomes considerable. Therefore, in the present embodiment, the steering angle detection value θ that is the steering input according to these calculation formulas and the reference target yaw rate ψ ^'*
A correlation with ₀ is shown in a control map using the vehicle speed detection value V as a parameter, and the reference target yaw rate ψ ^'* ₀ is calculated and set by linearly interpolating this control map according to the read vehicle speed detection value V. And According to this, it is possible to reduce at least the calculation load related to the complicated calculation of each calculation formula and shorten the processing time.

Conventionally, this reference target yaw rate ψ ^'* ₀ is used as the target yaw rate as it is or almost as it is, that is, as the target yawing momentum, and the problem associated therewith will be described with reference to the timing chart of FIG. Now, when the vehicle speed V is constant and the vehicle is traveling at a constant speed, the reference target yaw rate ψ ^'* ₀ is set without considering the delay with respect to the steering input, that is, the generation of the steering angle θ.
It is assumed that a reference target yaw rate ψ ^'* ₀ as shown by a broken line in FIG. 6 is calculated and set by turning up and turning back fast or large steering such as lane change in a high speed running state.

In general, when the reference target yaw rate ψ ^'* ₀ is calculated by using the delay calculation, the actual yaw rate ψ' actually generated with a first-order lag in the vehicle is required for the turning characteristic or turning. The time constant is set so that a uniform delay time is achieved according to the characteristics. In addition, the control gain of the feedback control system is set so that the actual yaw rate ψ 'actually generated in the vehicle does not become too small or too large with respect to the target reference target yaw rate ψ ^{' *} ₀ that is generally a target. Therefore, in short, it is assumed that the actual yaw rate occurs in the same manner as the target yaw rate after a predetermined delay time with respect to the target yaw rate. The time constant at this time will be referred to as a large time constant, and similarly, the control gain of the feedback control system will be small.

Then, as shown in the figure, with respect to a high steering speed or a large increase or decrease of the operation input as a driver's consciousness, the time constant is large, that is, the delay is large and the control gain is small, that is, the target value. When the yaw rate feedback control with a small suppression force is executed, the actual yaw rate ψ ′ at the steering input switching point, that is, the extreme point of the steering angle θ remains as the vehicle inertia as shown by the chain double-dashed line in FIG. For example, the vehicle behavior may become unstable due to the inertia of the yawing motion still remaining even after the lane change is completed.

A simple means for improving the convergence of the motion of such a delay system is generally to increase the control gain or decrease the time constant. However, increasing the control gain or decreasing the time constant without changing the target value results in increasing the control amount at the control time, so the actual yaw rate ψ ′ generated by such a control mode is increased. As shown by the solid line in Fig. 6, although the delay time is certainly shortened, it becomes larger than the target yaw rate ψ ^'* . Therefore, the actual yaw rate ψ ′ at the extreme point of the steering angle θ is amplified by the vehicle inertia, and the convergence of the vehicle behavior seen in time series may be further deteriorated.

As described above, it has become clear that the convergence of the actual yawing motion of the vehicle is not improved even if the control gain is increased or the time constant is decreased without changing the target value of the yawing motion of the vehicle. Therefore, in the present embodiment, the target yaw rate itself, which is the target value, is corrected to be small when such a high steering speed or a large operation input is detected, that is, when a sudden steering state is detected in the present invention. Specifically, the steering angular velocity θ ′ that is the steering input
Calculating a steering input is cut increases direction, i.e. the steering angular velocity theta 'is positive in a by and the steering angular velocity theta' is a predetermined steering angular velocity increases threshold theta _'1 or more, with increasing inherently steering angle theta Filtering is performed to reduce the increase rate of the reference target yaw rate ψ ^'* ₀ that is set to increase, and more specifically, it is the offset amount of the target value when the steering speed θ'is positive thereafter. A certain target yaw rate maximum increase / decrease amount C is set to a predetermined value C ₂ set to a relatively small value, and this target yaw rate maximum increase / decrease amount C is added to the previous target yaw rate value ψ ^'* _(n-1). I decided to go.
Also, changes in direction switching back the steering input, i.e., 'when it comes to ₂ or less, the steering angular velocity theta' steering angular speed theta 'is and the steering angular velocity is negative theta' is a predetermined steering angular velocity decreases threshold theta is positive A limiter is applied so that the previous value ψ ^'* _{(n-1) of the} target yaw rate, which has been slightly corrected with respect to the reference target yaw rate ψ ^{' *} ₀ by filtering at some point, does not increase or decrease. , After this,
The maximum increase / decrease amount C of the target yaw rate is set to "0" until the previous value ψ ^'* _(n-1) of the target yaw rate becomes the reference target yaw rate ψ ^{' *} ₀ or more.

From a control engineering point of view, the limiter is considered to be a part of the filter. However, the filtering for reducing the increase / decrease rate of the target value in this way reflects the steering input by the driver's intention in the yawing motion. Since there is an action of reducing the value itself, it is possible to control the vehicle behavior, that is, the magnitude of the yawing momentum while matching the steering direction and the yawing momentum in the present embodiment with the control direction and the actual vehicle behavior. it can. Further, the limiter that prevents the target value from increasing or decreasing itself can prevent the target yawing momentum from increasing or decreasing unnecessarily due to a steering input due to a driver's erroneous judgment. If the follow-up control is performed with, it becomes possible to suppress the yawing momentum that appears in the vehicle from becoming excessive and improve the convergence of the vehicle behavior.

Further, in the present embodiment, in response to the steering input,
When filtering the target yaw rate set by
Is the feedback control used in the arithmetic processing of FIG.
Your gain K₂A slightly larger predetermined value K_{twenty one}Set to
When applying a limiter to the standard yaw rate,
Control gain K₂A larger predetermined value K_{twenty two}Set to
In other cases, the feedback control gain K₂To
Relatively small predetermined value K ₂₀Shall be set to. The above
If the target yaw rate is filtered like
The steering angular velocity θ'indicating the steering speed is a threshold value θ '₁Since
Steering that will occur over time because it is increasing above
The actual input up to the end point, that is, the maximum point of the steering angle θ
The increase in yaw rate ψ'is reduced by filtering.
Corrected target yaw rate ψ^'*Kept close to
The vehicle behavior in response to steering input such as subsequent turning back
To improve the convergence of the control or response to yawing motion control
You can Also, is there a limiter on the target yaw rate?
If it is violated, the steering angular velocity θ'indicating the steering speed
Is a certain threshold θ '₂Because it is decreasing below
Steering input generated at the convergence point or steering input in the opposite direction
The actual yaw rate ψ'up to the starting point of increasing the force is
Target yaw rate ψ corrected slightly by^'*To
It is better to keep the vehicle closer to the steering input after that.
Improved convergence of motion or response to yaw motion control
can do.

The reason why the feedback control gain K ₂ when the target yaw rate is filtered is not suddenly set to a large predetermined value is as follows. For example, if the driver inputs a steering input in a fast or large turning direction at the beginning of steering during a normal turning turn due to a driver's misjudgment, etc., then a steering input in a slow or small turning direction is given. The target yaw rate is set to a value smaller than the reference target yaw rate because the target yaw rate is filtered in response to a fast or large steering input in the steering direction at the initial stage of the steering. If the feedback control gain K _{2 at} this time is too large, the actual yaw rate generated in the vehicle will be suppressed to a small value or the actual yaw rate will increase with respect to the fast or large steering input given at the initial steering. Is also amplified to a large value, which may cause a sense of discomfort by causing a discrepancy between the turning performance expected by the driver and the actual turning performance of the vehicle. Therefore,
When filtering the steering input in the turning direction, the increase gradient of the target yaw rate is set to be slightly large and the feedback control gain is not set to a very large value. It tries to prevent the discomfort by speeding up the agreement with.

Next, based on the principle of the invention as described above, the target
-Current (absolute) value of rate ψ^'* _(n)To calculate
The process executed in step S107 of the arithmetic processing shown in FIG.
The inner program will be explained according to the flowchart of FIG.
It In the figure, the target yaw rate control flag F₁Is
Correct the target yaw rate in the set state of "1" to a small value.
The reset state is indicated by "0". Also,
Each predetermined value set for the target increase / decrease amount of yaw rate C
C₁, C₂Is the predetermined value C as described above.₂Is relatively small
A small value and C₁> C₂Satisfies the conditions of and book
In the embodiment, the predetermined value C ₁Is the maximum increase / decrease in target yaw rate
When set to C, it is assumed that almost all standard items are
Change rate of standard yaw rate (at the sampling time ΔT
Change amount). In addition,
Feedback control gain K₂Each predetermined value set in
K₂₀, K_{twenty one}, K_{twenty two}Is K as described above₂₀<K_{twenty one}<K_{twenty two}of
The condition shall be satisfied.

In this calculation process, first, step S1
Then, using the steering angle θ read in step S101 of the calculation processing of FIG.
To calculate. θ ′ = d | θ | / dt (12) Next, the process proceeds to step S2 and step S1 in FIG.
Using the steering angle θ and vehicle speed V read in 01, the following 1
Reference target yaw rate ψ ^'*
₀ is calculated and set.

Ψ ^'* ₀ = f ₁ (θ, V) (13) Next, the process proceeds to step S3, and the reference target yaw rate ψ ^{' *} ₀ calculated and set in step S2 is stored in the storage device. The previous value ψ of the target yaw rate updated and stored in 44c.
^It is determined whether or not it is larger than ^'* _(n-1) . If the reference target yaw rate ψ ^{' *} ₀ is larger than the previous target yaw rate ψ ^'* _{(n-1), the process} proceeds to step S4. If not, the process proceeds to step S5.

In step S5, the target yaw rate control flag F ₁ is reset to "0", and then step S6.
Move to. On the other hand, in step S4, determines whether the target yaw rate control flag F ₁ is in the set state of "1", the target yaw rate control flag F ₁ is "1"
If it is in the set state, the process proceeds to step S7, and if not, the process proceeds to step S8.

Then, in step S8, it is determined whether or not the steering angular velocity θ'calculated and set in step S1 is "0" or more. If the steering angular velocity θ'is "0" or more, Moves to step S9, otherwise moves to step S6. Furthermore, the step S9, the step S1 steering angular velocity theta calculated set at 'said predetermined steering angular velocity increases threshold theta' determines whether or not _one or more, the steering angular velocity theta 'is a predetermined steering angular velocity increases threshold If θ ′ ₁ or more, the process proceeds to step S10, and if not, the process proceeds to step S6.

In step S10, the target yaw rate control flag F ₁ is set to "1", and then step S1
Move to 1. In step S7, it is determined whether the steering angular velocity θ'calculated and set in step S1 is "0" or more. If the steering angular velocity θ'is "0" or more, the step is performed. If it is not, the process proceeds to step S12.

[0072] Then, in step S12, the calculated set in step S1 steering angular velocity theta 'is the predetermined steering angular velocity decreases threshold theta' determines whether or not ₂ or more, the steering angular velocity theta 'is a predetermined steering If it is equal to or greater than the angular velocity increase threshold value θ ′ ₂ , the process proceeds to step S11, and if not, the process proceeds to step S13. Step S6
Then, the target yaw rate maximum increase / decrease amount C is set to the relatively large predetermined value C ₁ and then the process proceeds to step S14.

In step S14, the feedback control gain K ₂ is set to the relatively small predetermined value K ₂₀ , and then the process proceeds to step S15. On the other hand, in the step S11, the target yaw rate maximum increase / decrease amount C
Is set to the relatively small predetermined value C ₂ and then the process proceeds to step S16. In step S16, the feedback control gain K ₂ is set to the slightly larger predetermined value K ₂₁ , and then the process proceeds to step S15.

In step S13, the target
Set the maximum yaw rate increase / decrease amount C to “0” and then
Go to step S17. In step S17,
Feedback control gain K₂Is the larger predetermined value
K_{twenty two}After setting to, the process proceeds to step S15. Previous
In step S15, the calculation setting in step S2 is performed.
Reference target yaw rate ψ^'* ₀And the storage device 44c
Previous value of target yaw rate read from^'* _(n-1)For
Then, the target yaw rate difference Δψ^'*Calculate
To do.

[0075]   Δψ^'*= | Ψ^'* ₀−ψ^'* _(n-1)｜ ………… (14) Then, the process proceeds to step S18, and at step S15,
Calculated target yaw rate difference Δψ^'*Is the step
Target yaw rate set in S6 or S11 or S13
It is determined whether or not it is larger than the maximum increase / decrease amount C, and the target
-Rate difference Δψ ^'*Is greater than the target yaw rate maximum increase / decrease amount C
If it is larger, move to step S19, and if not,
If so, the process proceeds to step S20.

In step S19, it is determined whether the reference target yaw rate ψ ^'* ₀ is greater than the previous target yaw rate ψ ^{' *} _(n-1) , and the reference target yaw rate ψ ^'* ₀ is determined.
^{If '*} ₀ is larger than the previous value ψ ^{' *} _{(n-1) of the} target yaw rate, the process proceeds to step S21, and if not, the process proceeds to step S22. Then, the step S2
At 0, the current value ψ ^{′ *} _(n) of the target yaw rate is set to the reference target yaw rate ψ ^{′ *} ₀ , and then the process returns to the main program shown in FIG.

Further, in the step S21, the following 15
After calculating and setting the current value ψ ^'* _(n) of the target yaw rate according to the formula, the process returns to the main program shown in FIG. ψ ^'* _(n) = ψ ^{' *} _(n-1) + C (15) In step S22, the current value ψ ^'* _(n) of the target yaw rate is calculated and set according to the following 16 equations. The process returns to the main program shown in FIG.

[0078]   ψ^'* _(n)= Ψ^'* _(n-1)-C ……… (16) Therefore, according to the arithmetic processing shown in FIG.
Steering input in the direction of slower turning
θ'is a positive steering angular velocity increase threshold θ '₁No more
As long as the target yaw rate control flag
Gu F₁Is not set to "1", and step S
6 the target yaw rate maximum increase / decrease amount C is relatively large
Fixed value C₁Is set to. Then in step S14
Feedback control gain K₂Is a relatively small predetermined value K₂₀Set up
Is determined, and in step S15, the sampling time
The amount of change in the target yaw rate achieved by ΔT
Standard yaw rate difference Δψ^'*Is the reference target yaw rate ψ^'* ₀When
Previous value of target yaw rate ψ ^'* _(n-1)Calculated from the deviation from
Be done. However, as described above, the target yaw rate maximum
A relatively large predetermined value C set for the increase / decrease amount C₁Is Sun
Almost all target yawley achieved in pulling time ΔT
Since it is larger than the increase / decrease change amount of
To step S20, the target yaw rate current value ψ
^'* _(n)Is the reference target yaw rate ψ at the sampling time
^'* ₀Is set to. Therefore, it is calculated according to the vehicle characteristics.
Target target yaw rate ψ^'* ₀Target yaw set to
Current value ψ^'* _(n)To the relatively small predetermined value
K₂₀Feedback control gain K set to₂For
The yaw rate feedback in the calculation process of FIG.
Existing yaw rate feedback if control is performed
At least equal to or better than the control device
Combining driving stability with excellent transient turning characteristics
I can get it.

[0079] On the other hand, the steering input to some extent or more fast turning-increasing direction, the 'and is increasing in a positive direction by a predetermined steering angular velocity increases threshold theta' steering angular velocity theta becomes ₁ or more, step S8 from step S4, S9 Through step S10
The target yaw rate control flag F _{1 for} correcting the target yaw rate to a small value is set to "1". This target yaw rate control flag F ₁ is not reset to "0" unless the reference target yaw rate ψ ^'* ₀ becomes equal to or less than the previous target yaw rate ψ ^{' *} _{(n-1) in} step S3. proceeds from step S4 to step S7, the steering input to some extent or more fast steering back direction, as long as the steering angular speed θ not 'is and the predetermined steering angular velocity decreases threshold θ diminishing the negative direction' smaller than _2, the step The process moves from S7 directly or through step S12 to step S11. This step S11, the target yaw rate maximum decrease amount C is the set relatively small predetermined value C _2, then the feedback control gain K ₂ in step S16 the relatively large predetermined value K ₂₁ are set. Then, in the subsequent step S15, the target yaw rate difference Δψ ^{′ *} is calculated. For example, in the initial steering input in the fast turning direction, the steering angular speed θ ′ is a positive predetermined steering angular speed increase threshold θ ′. If the target yaw rate previous value ψ ^'* _(n-1) up to then is ₁ or more, even if the previous target yaw rate ψ ^{' *} ₀ is the reference target yaw rate ψ ^'* ₀ It is considered that the reference target yaw rate ψ ^'* ₀ at the time of this calculation, which is calculated according to the angle θ, has also increased significantly. Therefore, the reference target yaw rate ψ ^{' *} ₀ at the time of this calculation and the previous value of the target yaw rate ψ ^{' The} target yaw rate difference Δψ ^'* obtained from the deviation from ^* _{(n-1 )} will also be a considerably large value.
Therefore, subsequent in step S18, primarily target yaw rate difference [Delta] [phi] ^'*, the shifted relatively to become larger than the predetermined small value C ₂ which is set to the target yaw rate maximum decrease amount C in step S19, the steering angle θ Since the reference target yaw rate ψ ^'* ₀ which increases with the increase is larger than the previous value ψ ^{' *} _(n-1) of the target yaw rate, the routine proceeds to step S21, where the current value ψ ^'* _(n) of the target yaw rate is obtained. Is a relatively small value that is the sum of the target yaw rate maximum increase / decrease amount C and the previous value ψ ^'* _(n-1) of the target yaw rate. Then, after this, the target yaw rate difference Δψ ^'* obtained from the deviation between the reference target yaw rate ψ ^{' *} ₀ and the previous value of the target yaw rate ψ ^'* _(n-1) should be further increased, and the steering angular velocity is immediately increased. Since it is considered that θ ′ does not decrease in the negative direction and becomes smaller than the predetermined steering angular velocity reduction threshold θ ′ ₂ , the current value ψ ^{′ *} _(n) of the target yaw rate is relatively small at each sampling time ΔT. The feedback control gain K ₂ during that time increases by a predetermined value C ₂ and continues to be set to the relatively large predetermined value K ₂₁ . Therefore,
The increase continues, but with respect to the current value ψ ^'* _{(n) of} the so-called filtered target yaw rate that is set smaller than the reference target yaw rate ψ ^{' *} ₀ , the relatively large predetermined value K Feedback control gain K set to ₂₁
If the feedback control of the yaw rate is executed in the calculation process of FIG. 5 by using ₂ , the delay can be relatively reduced while suppressing the actual yaw rate from becoming excessive. That is, it is possible to suppress the increase of the vehicle inertia at the steering input switching point, that is, the maximum point of the steering angle θ, which will occur eventually, while obtaining the maneuverability.

[0080] Eventually switched the steering input, the steering input to some extent or more fast steering back direction, the steering angular velocity theta 'is reduced while and a predetermined steering angular velocity decreases threshold theta in the negative direction' is smaller than _2, wherein said step In S3, the reference target yaw rate ψ ^'* ₀ is the previous value of the target yaw rate ψ ^{' *} _(n-1)
Unless otherwise, the process proceeds to step S13 via steps S4, S7 and S12. The step S13 the target yaw rate maximum decrease amount C is set to "0", then the further large predetermined value K ₂₂ are set in the feedback control gain K ₂ in step S17. Then, in the subsequent step S15, the target yaw rate difference Δψ ^{′ *} is calculated. The previous value ψ ^{′ of the} target yaw rate which has been corrected by the filtering to be correspondingly smaller than the reference target yaw rate ψ ^{′ *} _{0 in the} previous calculation. ^The target yaw rate difference Δψ ^'* obtained from the deviation between ^* _(n-1) and the reference target yaw rate ψ ^{' *} ₀ will also be a considerably large value. Therefore, in the following step S18, mainly the target yaw rate difference Δψ ^'*
Becomes larger than the target yaw rate maximum increase / decrease amount C which is “0”, the process proceeds to step S19, and the steering angle θ
Since the reference target yaw rate ψ ^'* ₀ that increases with the increase of the target yaw rate is larger than the previous value ψ ^{' *} _(n-1) of the target yaw rate, the routine proceeds to step S21, where the current value ψ of the target yaw rate ψ
^'* _(n) is set to the previous value ψ ^{' *} _(n-1) of the target yaw rate. Then, after that, it is obtained from the deviation between the reference target yaw rate ψ ^'* ₀ and the previous target yaw rate ψ ^{' *} _(n-1) , which decreases with the decrease of the steering angle θ due to the steering input in the reverse direction. The target yaw rate difference Δψ ^'* should gradually decrease, but immediately the reference target yaw rate ψ ^{' *} ₀
^'Since not less ^* _(n-1), the current value ψ of the target yaw ^rate' but the previous value ψ of the target yaw rate ^* _(n), from the steering angular velocity theta 'is negative predetermined steering angular speed decreases threshold theta' ₂ The previous value of the target yaw rate immediately after it becomes small is maintained at ψ ^'* _(n-1), and the feedback control gain K ₂ during that time is maintained.
Continues to be set to the larger predetermined value K ₂₂ . Therefore, with respect to the current value ψ ^'* _(n) of the target yaw rate which is a constant value smaller than the reference target yaw rate ψ ^{' *} _0, the feedback control gain K set to the larger predetermined value K ₂₂ is set.
If the feedback control of the yaw rate is executed in the calculation process of FIG. 5 by using ₂ , the actual yaw rate ψ ′ can be rapidly decreased toward the current value ψ ^{′ *} _(n) of the target yaw rate. It will be possible to improve the convergence of the vehicle behavior by rapidly reducing the vehicle inertia while achieving stable running stability.

Further, at the time of turning back the steering input as described above, if the decreasing reference target yaw rate ψ ^'* ₀ becomes equal to or less than the previous target yaw rate ψ ^{' *} _(n-1) , step S
3 to step S5, the target yaw rate control flag F ₁ is reset to "0", and then step S6
In steps S15, S18 and S20, the reference target yaw rate ψ ^'* ₀ is set to the current value ψ ^{' *} _(n) of the target yaw rate, and the feedback control gain K ₂ is set to the relatively small predetermined value K _20. It Therefore, thereafter, the normal yaw rate feedback control is performed by the calculation processing of FIG. 7, but the vehicle inertia is sufficiently increased by the rapid decrease of the actual yaw rate ψ ′ including the switching of the fast or large steering input until then. For example, when the steering input converges after that, the turning traveling of the vehicle is quickly converged, and the yaw rate that appears there is relatively slow as described above,
A supple ride quality like the above-mentioned profound feeling is exhibited. Further, for example, when the steering input is further increased in the reverse direction thereafter, the increase in the actual yaw rate ψ ′ in the additional direction is accelerated and the turning performance of the vehicle, that is, the maneuverability is improved.

In the above-described embodiment, the yawing momentum control device for simultaneously performing the increase / change setting of the feedback control gain at the time of correcting the target yawing momentum decrease composed of the target yaw rade has been described. This does not necessarily have to be performed at the same time. To delete this feedback control gain increase / change setting function, steps S14, S16 and S17 in the arithmetic processing of FIG. 7 may be deleted.

As described above, the present embodiment is an implementation of the vehicle yawing momentum control device according to any one of claims 1 to 4 of the present invention, and step S1 in the arithmetic processing of FIG.
01 corresponds to the steering state detecting means and the vehicle speed detecting means of the yawing momentum control device for a vehicle according to the present invention.
Step S2 of the arithmetic processing of FIG. 7 corresponds to the target yawing momentum setting means, and steps S1 and S of the arithmetic processing of FIG.
4, S9, S12 correspond to the sudden steering state detecting means, and these and the steps S2, S6, S14, S16, S1.
The entire calculation processing of FIG. 7 except 7, and S20 corresponds to the target yawing momentum correction means, the steps S14, S16 and S17 of the calculation processing of FIG. 7 correspond to the feedback control gain setting means, and the calculation processing of FIG. Step S102 corresponds to yawing momentum detecting means, and the step S1 is performed.
The whole arithmetic processing of FIG. 5 except 01 corresponds to the feedback control means.

Next, the operation of the yaw rate feedback control by the arithmetic processing of FIG. 5 including the arithmetic processing of FIG. 7 will be described with reference to the time chart of FIG. This time chart is a simulation when the lane change is performed by turning the steering wheel to the right and then to the left when the vehicle speed V is constant and the vehicle is running at a high speed. Then, in order to facilitate understanding, FIG. 8a shows a change over time in which the reference target yaw rate ψ ^'* ₀ equally appears with no time delay with respect to the steering angle θ.
FIG. 8b shows a change with time of the absolute value | θ | of the steering angle, and FIG. 8c shows a change with time of the steering angular velocity θ ′ obtained by differentiating the absolute value of the steering angle | θ | 8d is the target yaw rate to be set (this time value)
Of the absolute value of | ψ ^'* _(n) |
FIG. 8e shows the actual yaw rate ψ'according to this target yaw rate ψ ^'* _{(n) and the} reference target yaw rate ψ ^{' *.}
₀ by shows the time course of the actual yaw rate [psi _'N. In addition, in this time chart, it is assumed that the torque for the above-described turning outer wheel slip speed countermeasure and tack-in countermeasure is always a constant value.

In this lane change simulation, as shown in FIG. 8a, the steering angle θ, which increases in a cubic curve from time t _{0 due} to the steering wheel turning to the right, terminates the turning operation at time t _4. Becomes maximum,
After that, the steering angle θ, which decreases in a quadratic curve by turning back to the left, once returns to “0”, that is, a moderate state at time t ₉ , but without changing the inclination at time t _4. The steering angle θ that shifts to the further leftward turn and decreases in a quadratic curve becomes the minimum at the time t ₁₁ when the additional turn is finished and further increases in a cubic curve by the rightward turnback. angle θ is again at a time t ₁₇ "0", that is to return to the moderate state, thereafter, this moderate state is maintained. It is assumed that the reference target yaw rate ψ ^'* ₀ calculated and set with respect to the steering angle θ appears equally without delay. Further, said time t ₀ steering angle began to increase in the positive direction from theta, since exceeding the approximate straight running condition threshold theta ₀ of the positive and recently time t ₀₁ from the time t _0, ignoring the time I will.

On the other hand, the absolute value of the steering angle | θ |
Appears as in FIG. 8b. That is, although the absolute value of the steering angle | θ | curve from the time t ₀ to the time t ₉ is equivalent to the curve of the steering angle θ itself, the following time t ₉ to the time t ₉
The absolute value of the steering angle of time of up to ₁₇ | θ | curve, the steering angle θ
It is the opposite of the sign of its own curve, so
The absolute value of the steering angle | θ | becomes maximum even at time t ₁₁ .
The steering angular velocity θ ′, which is the time derivative of the absolute value of the steering angle | θ |, appears as shown in FIG. 8c. That is, the time t ₀
The steering angular velocity θ ′ that increases in a cubic curve becomes maximum at time t ₃ at which the increasing slope of the absolute value of the steering angle | θ | reaches a maximum, and then turns to a cubic curve to decrease the steering angle. Of the absolute value | θ | of the steering angle is converged to “0” at time t _{4 when} the inclination of the absolute value | θ | Time t ₉
And becomes the minimum. However, after this time t ₉ , the absolute value of the steering angle | θ | turns to increase and the increasing slope at the time t ₉ is the maximum, so the steering angular velocity θ ′ is calculated at this time t 9.
_{At 9} on the border, it increases instantaneously (including at least one sampling time ΔT) and reaches a maximum. After that, at the time t ₁₁ at which the inclination of the absolute value of the steering angle | θ | becomes “0” after turning into a cubic curve-like decrease, it converges to “0” once, and further decreases like a cubic curve. It becomes minimum at time t ₁₄ when the decreasing gradient of the absolute value of the steering angle | θ | becomes maximum. Thereafter, it converged to "0" at the time t ₁₇ indicating the steering end turned to again tertiary curve increase. In the temporal change of the steering angular velocity θ ′, the steering angular velocity θ ′ that increases in the positive region becomes equal to or greater than the positive predetermined steering angular velocity increase threshold θ ′ ₁ at time t ₁ , and then decreases in the negative region. θ ′ becomes smaller than the negative predetermined steering angular velocity increase threshold θ ′ ₂ at time t ₅ . Further, the steering angular velocity θ ′ that instantaneously increases in the positive region becomes equal to or larger than the positive threshold steering angular velocity increase threshold θ ′ _{1 at} time t ₉ , and thereafter the steering angular velocity θ ′ that decreases in the negative region is the time t. _{At 12} , the value became smaller than the negative steering angle speed increase threshold value θ ′ ₂ .

The change in steering angular velocity θ ′ with time causes
Absolute value of (the current value of) standard yaw rate | ψ^'* _(n)Is the figure 8
Appears like d. That is, the set target yaw rate
Previous value ψ^'* _(n-1)Is the reference target yaw rate ψ^'* ₀Is equivalent to
Moreover, the steering angular velocity θ ′ that increases in the positive region is still
Positive steering angle velocity increase threshold θ '₁Less than said time
t₀From time t₁Up to the target yaw rate (of
Absolute value of this value) ψ ^'* _(n)| Is the standard target yaw rate
Ψ^'* ₀, And at the same time feedback control gain
K₂Is the relatively small predetermined value K₂₀Is set to. Only
However, the steering angular velocity θ'that increases in the positive range is
Predetermined steering angular velocity increase threshold θ '₁Time t which is above₁From
The steering angular velocity θ ′ turns to decrease and the steering angular velocity decreases.
The degree θ'is the predetermined steering angular velocity increase threshold value θ'that is the negative value.₂Less than
Time t_FiveUntil the target yaw rate
Filtering is performed. That is, in the detailed view of FIG. 8d
As shown in the figure, the sampler in which the arithmetic processing of FIG.
The target yaw rate maximum increase / decrease amount C is set every
Specified relatively small predetermined value C₂Target yaw rate
Absolute value of (current value of) | ψ^'* _(n)｜ increases, but this
Since the sampling time ΔT is relatively short,
Macroscopically, it is assumed that the slope has increased uniformly. Therefore,
This time t₁From time t_FiveTarget yaw rate until time
Absolute value of (current value of) | ψ^'* _(n)| Is the standard target yaw
Ψ^'* ₀The target of the standard while reflecting the increasing trend of
Yaw rate ψ^'* ₀Is set to a smaller value. In addition,
This time t₁From time t_FiveTime to feedback
Control gain K₂Is the relatively large predetermined value K_{twenty one}Set to
Keep going. Also, the time t_FiveFrom the target yawley
Target yaw rate after that
Absolute value of (current value of) | ψ^'* _(n)| Is the time t_Fiveof
The target yaw rate set at the last sampling time
Absolute value of previous value | ψ^'* _(n-1)Maintained at |, resulting in
Time t₇Is the absolute value of (the current value of) the target yaw rate |
ψ^'* _(n)| Is the reference target yaw rate ψ^'* ₀It became the following.
Therefore, the time t_FiveFrom time t₇Until time fee
Feedback control gain K₂Is a larger predetermined value K_{twenty two}To
The setting continues, and at this time t₇After that, at least the steering
The angular velocity θ ′ is momentarily increased by the positive steering angle velocity increase threshold.
Value θ '₁Time t which is above₉Up to the target yaw
Absolute value of (current value of) | ψ^'* _{(n )}| Is the standard target
Rate ψ^'* ₀Set to, and feedback control at the same time
Gain K₂Is the relatively small predetermined value K₂₀Set to
It

Further, the operation that increases instantaneously to the positive region is performed.
The steering angular velocity θ ′ is the positive steering angle velocity increase threshold θ ′.₁
Time t which is above₉The steering angular velocity θ'decreases and
The decreasing steering angular velocity θ'is the negative steering angle
Speed increase threshold θ '₂Smaller time t₁₂Time to
Is the time t₁From time t_FiveGoal as well as time to
The yaw rate filtering is executed at this time t.₉
From time t₁₂Target yaw rate up to (current value of)
Absolute value of | ψ^'* _(n)| Is the reference target yaw rate ψ ^'* ₀of
Reflecting the increasing tendency, the reference target yaw rate ψ
^'* ₀Set to a smaller value and feedback at the same time
Control gain K₂Is the relatively large predetermined value K_{twenty one}Set to
Keep going. Also, the time t₁₂From the target yawley
The target yaw rate after this
Absolute value of (current value of) | ψ^'* _(n)| Is the time t₁₂of
The target yaw rate set at the last sampling time
Absolute value of previous value | ψ^'* _(n-1)Maintained at |, resulting in
Time t₁₅Is the absolute value of (the current value of) the target yaw rate |
ψ^'* _(n)| Is the reference target yaw rate ψ^'* ₀Became
Therefore, the time t₁₂From time t₁₅Time to feed
Back control gain K₂Is a larger predetermined value K_{twenty two}Set up
Continues to be set at this time t₁₅After that, the steering angular velocity θ'is
Time t when it converges to “0”₁₇Up to the target yaw
Absolute value of (current value of) | ψ^'* _(n)| Is the standard target
Rate ψ^'* ₀Set to, and feedback control at the same time
Gain K₂Is the relatively small predetermined value K₂₀Set to
It

The absolute value | ψ ^'* _(n) | of the target yaw rate (current value) thus set is matched with the sign (direction of turning) according to the steering direction by the calculation process of FIG. The target yaw rate ψ ^{′ *} _(n) of this target yaw rate is shown by a broken line in FIG. 8e. Also, this target yaw rate (this time value) ψ ^'*
_(n) and the actual yaw rate ψ ′ according to the feedback control gain K ₂ set at each time are shown by the solid line in FIG.
Here, as described above, increasing or decreasing the feedback control gain K ₂ is considered to be equivalent to simply increasing or decreasing the time constant τ of the first-order lag system when viewed from the output side of the control amount, and in general, the time constant τ However, since it is defined as the time until the measured value reaches about 63% of the target value, the change of the actual yaw rate ψ ′ is considered for each set time zone of each target yaw rate.

For example, during the period from the time t ₀ to the time t ₁ , the target yaw rate (current value) ψ ^'* _(n) is set to increase with the reference target yaw rate ψ ^{' *} ₀ in a positive region. Since the feedback control gain K ₂ is set to the relatively small predetermined value K ₂₀ , the time constant τ is equivalent to the feedback control gain K ₂ set to the predetermined value K ₂₀ from the time t ₁ , for example. at time t ₀ ~t ₂ up to time t ₂ after the delay time to, the actual yaw rate ψ '
Rises and increases relatively slowly as in the normal target yaw rate tracking control.

Subsequent time t₁From time t_FiveIn time to
Is the target yaw rate (current value of) ψ^'* _(n)Each sampler
A relatively small predetermined value C for each₂Set to
The target yaw rate is increased or decreased by the maximum increase / decrease amount C in the positive direction
Quasi-target yaw rate ψ^'* ₀Corrected to a smaller absolute value
And feedback control gain K₂Is relatively large
Predetermined value K_{twenty one}Is set to, for example, the time t_FiveOr
, The predetermined value K_{twenty one}Feedback control
In K₂Time after the delay time equivalent to time constant τ equivalent to
t₆Time to₂~ T₆Then, the target yaw rate (of
This time value) ψ^'* _(n)Absolute yaw rate ψ '
When the logarithm is small, the feedback control gain
K₂The actual yaw rate ψ'which is quickly increased by
The actual yaw rate ψ'generated by accelerating both inertias is
-Rate (current value of) ψ^'* _(n)Can overshoot
However, after that, the target yaw rate (this time value) ψ^'*
_(n)Is the reference target yaw rate ψ^'* ₀Than absolute value
It becomes a small value and the feedback control gain K₂
The real yaw
The ψ ′ gradually decreases in the positive region. Therefore, the above criteria
Target yaw rate ψ^'* ₀Is the target yaw rate (now
Times) ψ^'* _(n)Set to and feedback control gain
K₂Is a relatively large predetermined value K_{twenty one}Real yaw when set to
Rate ψ '_NIs the reference target yaw rate ψ^'* ₀than
While it is greatly delayed and amplified, in the actual vehicle
The actual yaw rate ψ'generated is the reference target yaw rate ψ
^'* ₀Is not significantly delayed and is amplified so much
Not even.

Subsequent time t_FiveFrom time t₇In time to
Is the target yaw rate (current value of) ψ^'* _(n)Is the time t
_FiveTarget yaw rate set at the sampling time immediately before
(Previous value of) ψ^'* _(n-1)Is maintained at the reference target yaw
Ψ^'* ₀Is corrected to a correspondingly smaller absolute value, and
Feedback control gain K₂Is a larger predetermined value K
_{twenty two}Is set to, for example, the time t₇From the above
Predetermined value K_{twenty two}Feedback control gain K set to₂
Time t after the delay time corresponding to the time constant τ equivalent to ₈Until
Time t₆~ T₈And the actual yaw rate ψ'is faster in the positive region.
The delay time is shortened as well. Therefore, less
Both the time t₈In the vicinity of
The running stability of the vehicle is improved and the convergence of the vehicle behavior is also improved.
It is thought that it has gone up.

Subsequent time t₇From time t₉In time to
Is the target yaw rate (current value of) ψ^'* _(n)Is the standard eye
Standard yaw rate ψ^'* ₀With the positive region set to decrease
And feedback control gain K₂Is relatively small
Fixed value K₂₀Is set to, for example, the time t₉Or
, The predetermined value K₂₀Feedback control
In K₂Time after the delay time equivalent to time constant τ equivalent to
t_TenTime to₈~ T_TenAnd the actual yaw rate ψ'is usually
As in the target yaw rate tracking control of
It decreases sharply, and smoothness in the moderate state of the steering angle θ
To live.

Subsequent time t₉From time t₁₂In time to
Is the target yaw rate (current value of) ψ^'* _(n)Each sampler
A relatively small predetermined value C for each₂Set to
The target yaw rate maximum increase / decrease amount C
Quasi-target yaw rate ψ^'* ₀Corrected to a smaller absolute value
And feedback control gain K₂Is relatively large
Predetermined value K_{twenty one}Is set to, for example, the time t₁₂Or
, The predetermined value K_{twenty one}Feedback control
In K₂Time after the delay time equivalent to time constant τ equivalent to
t₁₃Time to_Ten~ T₁₃Then, the target yaw rate (of
This time value) ψ^'* _(n)Absolute yaw rate ψ '
When the logarithm is small, the feedback control gain
K₂Real yawley quickly reduced in the negative region by
Actual yaw rate generated by acceleration of vehicle inertia
ψ'is (current value of) target yaw rate ψ ^'* _(n)Over the
The target yaw rate (of
This time value) ψ^'* _(n)Is the reference target yaw rate ψ^'* ₀Than phase
However, the absolute value becomes smaller and the feedback system
Your gain K₂By expressing a relatively strong inhibitory force
The actual yaw rate ψ'increases gradually in the negative region. Obey
The reference target yaw rate ψ^'* ₀The target yaw
Rate (current value of) ψ^'* _(n)Set to
Control gain K₂Is a relatively large predetermined value K_{twenty one}Set to
Real yaw rate ψ '_NIs the reference target yaw rate
ψ^'* ₀It is delayed and amplified more than
The actual yaw rate ψ ′ actually generated in the vehicle is the reference target.
Yaw rate ψ^'* ₀Without being significantly behind
Not so much amplified.

Next time t₁₂From time t₁₅In time to
Is the target yaw rate (current value of) ψ^'* _(n)Is the time t
₁₂Target yaw rate set at the sampling time immediately before
(Previous value of) ψ^'* _(n-1)Is maintained at the reference target yaw
Ψ^'* ₀Is corrected to a correspondingly smaller absolute value, and
Feedback control gain K₂Is a larger predetermined value K
_{twenty two}Is set to, for example, the time t₁₅From the above
Predetermined value K_{twenty two}Feedback control gain K set to₂
Time t after the delay time corresponding to the time constant τ equivalent to ₁₆Until
Time t₁₃  ~ T₁₆And the actual yaw rate ψ'in the negative region
It increases rapidly and the delay time is shortened. Therefore,
At least the time t₁₆In the vicinity of
The driving stability of the vehicle is improved and the convergence of the vehicle behavior is also improved.
It is considered to have improved.

Next time t₁₆From time t₁₇In time to
Is the target yaw rate (current value of) ψ^'* _(n)Is the standard eye
Standard yaw rate ψ^'* ₀Set to increase in the negative area with
And feedback control gain K₂Is relatively small
Fixed value K₂₀Is set to, for example, the time t₁₇Until
, The actual yaw rate ψ'is the normal target yaw rate
Similar to the slave control, it decreases relatively slowly in the positive range,
Both behaviors produce smoothness at a moderate steering angle θ
However, in the present embodiment, the time t₁₆Real yaw rate up to ψ '
The convergence state of accelerates the vehicle inertia in the direction of convergence of the vehicle behavior.
Effectively, the time t₁₇And the actual yaw rate ψ '
It converged to "0".

Then, after the time t ₁₇ , the actual yaw rate ψ ′ exceeds the positive yaw rate convergence threshold ψ ′ ₀ in the time until the time t ₁₈ when the predetermined time T ₀ elapses. -Ψ ' ₀ ). As described above, according to the yaw rate feedback control device of the present embodiment, it is possible to suppress the delay or amplification of the yaw rate generated in the vehicle at the time of a fast or large steering input such as a lane change and when the steering input converges. Therefore, the convergence of the vehicle behavior required thereafter is also improved.

In the above embodiment, the target yaw rate ψ ^'*
In correcting the _value smaller than the reference target yaw rate ψ ^'* ₀ , the filter is applied when the threshold value in the steering increasing direction is exceeded, and the limiter is applied when the threshold value is exceeded in the steering returning direction. The correction mode of the target yaw rate required in the vehicle yaw momentum control device of the present invention is not limited to this, and various modifications are possible,
For example, as shown in FIG. 9, the target yaw rate ψ ^'* is limited from the time when it exceeds the threshold value in the steering increasing direction, and the limiter is released when the reference target yaw rate ψ ^{' *} ₀ falls below this target yaw rate ψ ^'*. Then, as shown in FIG. 10, the target yaw rate ψ ^'* is subjected to the increase restriction filter and the reference target yaw rate ψ ^{' *} ₀ starts to decrease from the time when the threshold value in the steering increasing direction is exceeded, that is, the steering input is switched back. target yaw rate [psi ^'* and reference target yaw rate [psi over reduced regulation ^{filter' *} ₀ is a possible correction aspects such Remove all filters at the time when below the target yaw rate [psi ^'*, they are required with It may be appropriately selected according to the vehicle characteristics and the like. However, for example, in FIG. 11, the target yaw rate ψ ^{'* is started} from the time when the threshold value in the steering increasing direction is exceeded ^.
The target control yaw rate ψ ^'*
_The filter is released when ₀ falls below this target yaw rate ψ ^'*. However, if the increasing or decreasing direction of the target yaw rate ψ ^{' *} changes significantly at the correction switching point, the vehicle behavior corresponding to this It should be noted that it may be jerky and may cause the driver to feel uncomfortable.

[0099] Also, in the embodiment has been described in detail a rear wheel drive vehicle, it can be similarly expanded to the left and right drive wheel differential control system for a front wheel drive vehicle.

Further, in the above-mentioned embodiment, the case where the microcomputer is applied as the control unit 40 has been described, but instead of this, electronic circuits such as a counter and a comparator may be combined. Further, in the above-described embodiment, only the one in which the vehicle yawing momentum control device is developed to the differential limitation control device between the rear left and right wheels has been described in detail, but the vehicle yawing momentum control device of the present invention is
The feedback control in which the actual yawing momentum generated in the vehicle is made to follow the target yawing momentum is applicable to all control devices. For example, it is described in JP-A-60-161255 previously proposed by the applicant. Auxiliary steering control device including a four-wheel steering control device described above and Japanese Patent Laid-Open No. 5-1933 previously proposed by the present applicant.
Japanese Patent Application Laid-Open No. 5-2452, which was previously proposed by the applicant of the present invention.
The braking force control device described in Japanese Patent No. 8 for individually controlling the braking force of each wheel, or the driving force distributed to the front and rear wheels described in Japanese Patent Application Laid-Open No. 2-290722 previously proposed by the applicant. It can be widely applied to a driving force distribution device for transmission.

[0101]

According to yawing momentum control system for a vehicle of the present invention as described above, according to the present invention, fast steering speed by correcting small target yawing momentum during input, the feedback control so as to follow the target yawing momentum By executing the above, it is possible to prevent the large actual yawing momentum remaining at the switching point of the steering input or the like from accelerating the vehicle inertia and suppressing the convergence of the vehicle behavior from being reduced. Also, by increasing the feedback control gain in accordance with this, it is possible to reduce the delay time of the actual yawing momentum at the switching point of the steering input or the like and the deviation from the target value. It can be further improved.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of a vehicle yaw momentum control device of the present invention.

FIG. 2 is a schematic configuration diagram showing an example in which the yawing momentum control device for a vehicle according to the present invention is applied to a differential limiting control device between rear left and right wheels.

3 is a schematic configuration diagram showing an example of a differential limitation control device between the left and right rear wheels in FIG.

FIG. 4 is a correlation diagram between a transmission driving force ratio of a differential limitation control device between the rear left and right wheels of FIG. 3 and a target position of a step motor.

5 is a flowchart showing an example of a calculation process of a target yawing momentum tracking feedback control performed by the rear left and right differential limitation control device of FIG.

6 is a correlation diagram of a target yawing momentum calculated in the calculation process of FIG. 5 and an actual yawing momentum based on a feedback control gain or a time constant.

7 is a flowchart showing a calculation process of a target yawing momentum correction setting, which is executed in the calculation process of FIG. 5 as an embodiment of the vehicle yawing momentum control device of the present invention.

8 is a time chart of a yawing motion by the arithmetic processing of FIG. 5 including the arithmetic processing of FIG.

FIG. 9 is an explanatory diagram of a target yawing momentum that is corrected and set as another embodiment of the vehicle yawing momentum control device of the present invention.

FIG. 10 is an explanatory diagram of a target yawing momentum that is corrected and set as another embodiment of the vehicle yawing momentum control device of the present invention.

FIG. 11 is an explanatory diagram of a target yawing momentum that is corrected and set as still another embodiment of the vehicle yawing momentum control device of the present invention.

[Explanation of symbols]

1 is the engine 2 is the transmission 3 is a propeller shaft 4 is a drive gear 5 is a ring gear 6L and 6R are rear left and right wheels 7L and 7R are multi-plate clutches 8L and 8R are left and right drive shafts 9L and 9R are front left and right wheels 10 is a steering wheel 11 is a differential case 12 is a differential gear 15L and 15R are fluid pressure cylinders 20 is an actuator unit 25L and 25R are proportional solenoid valves 40 is a control unit 41 is a steering angle sensor (steering state detecting means) 42 is a vehicle speed sensor (vehicle speed detecting means) 43 is a yaw rate sensor (yaw momentum detecting means) 51 is a microcomputer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ ID FI // B62D 101: 00 B62D 101: 00 113: 00 113: 00 117: 00 117: 00 137: 00 137: 00 (56) Reference Documents JP-A-4-331669 (JP, A) JP-A-62-225462 (JP, A) JP-A-6-206458 (JP, A) JP-A-5-193510 (JP, A) JP-A-60- 161255 (JP, A) JP-A-3-31030 (JP, A) JP-A-5-24528 (JP, A) JP-A-5-193332 (JP, A) JP-A-3-92482 (JP, A) JP-A-4-27667 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60K 23/00-23/08 B60K 17/10-17/36 B62D 6/00 B60T 8 / 58

Claims (4)

(57) [Claims] And 1. A steering state detecting means for detecting a steering state given as steering input of the vehicle, and a car Hayaken detecting means for detecting a longitudinal direction vehicle speed of the vehicle, the yawing momentum is actually generated in the vehicle detection a yawing motion amount detecting means for steering detected by at least the steering state detecting means
Target yawing momentum setting means for setting a target yawing momentum to be achieved by the vehicle based on the angle , and the yawing momentum detected by the yawing momentum detecting means match the target yawing momentum set by the target yawing momentum setting means. As described above, in the yawing momentum control device for the vehicle, which includes the feedback control means for performing the feedback control using the predetermined feedback control gain, the steering state detection means detects
Steering angular velocity calculation that calculates the steering angular velocity based on the steering angle
Output means and steering angle calculated by the steering angular velocity calculation means
Bother speed Ru fast der above given, and quick steering state detecting means for detecting that a quick steering state, when said abrupt steering state detecting means detects that a quick steering state, the A yawing momentum control device for a vehicle, comprising: a target yawing momentum correcting means for correcting the target yawing momentum to a small value. 2. The target yawing momentum correction means,
The yawing momentum control device for a vehicle according to claim 1, further comprising a filter unit that regulates an increase / decrease rate of the target yawing momentum. 3. The target yawing momentum correction means,
3. The yawing momentum control device for a vehicle according to claim 1, further comprising limiter means for preventing an increase / decrease in the target yawing momentum. 4. The feedback control gain setting means for setting a large feedback control gain of the feedback control means when the target yawing momentum correction means corrects the target yawing momentum small. 4. The vehicle yawing momentum control device according to any one of 1 to 3.