JP3468046B2 - Vehicle yawing control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit lowering of the running speed of a vehicle during yawing control. SOLUTION: If actual yaw rate ωr is smaller than desired yaw rate ωt by a set value or more while a vehicle is turning to the left, fluid-pressure braking torque applied to an inner turning wheel 12 is increased, and driving torque is also increased by an amount equal to the increase in the fluid pressure braking torque under control of an electric motor 28. Leftward yawing moment is produced in the vehicle to bring the actual yaw rate close to the desired yaw rate. In this case, since the delay of response is small under control of the electric motor 28, the increase in the driving torque and the increase in the fluid pressure braking torque can be caused almost simultaneously, so that a decrease in vehicle speed can be inhibited. Also, since the amount of increase in the driving torque is almost equal to the amount of increase in the fluid pressure braking torque, the amounts of changes in torque as the whole vehicle can be reduced, and thus changes in vehicle speed can be inhibited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle yawing control device for controlling yawing of a vehicle having four or more wheels including four wheels located in front, rear, left and right.

[0002]

2. Description of the Related Art An example of the above-mentioned vehicle yawing control device is described in Japanese Patent Laid-Open No. 3-276852.
The vehicle yawing control device described in this publication is provided in a four-wheel vehicle including a hydraulic braking device as a friction braking device and an internal combustion engine as a drive source. The hydraulic braking device includes a hydraulic pressing device that presses a friction member against a brake rotating body that rotates with each of the four wheels by hydraulic pressure, and a hydraulic braking torque according to the hydraulic pressure is applied to each wheel. . During yawing control of the vehicle, the yawing control device controls the friction braking device for the left and right drive wheels and the internal combustion engine. The hydraulic braking torque is applied to the turning inner wheel of the left and right drive wheels to bring the actual yaw rate closer to the target yaw rate, and the drive torque is increased by the control of the internal combustion engine to add the hydraulic braking torque to the vehicle. The decrease in traveling speed is suppressed.

[0003]

DISCLOSURE OF THE INVENTION Problems, Solutions, Actions and Effects to be Solved by the Invention However, in a vehicle equipped with the above-mentioned vehicle yawing control device, the drive torque of the drive wheels is increased by the control of the internal combustion engine. Therefore, there is a problem that the response delay is large. For example, there is a large delay in the increase in drive torque with respect to the addition of hydraulic braking torque,
Since a decrease in the traveling speed of the vehicle is unavoidable during that time, there is a problem that the driver feels uncomfortable. Therefore, an object of the present invention is to obtain a vehicle yawing control device with a small control delay of drive torque during vehicle yawing control.

The above problem is solved by the following vehicle yawing control device. In the following description, each aspect of the present invention will be described in the same format as the claims, with each item being assigned a different item number, with reference to other item numbers as necessary. This is to clarify the possibility of adopting the features described in each section in combination. (1) A vehicle yawing control device for controlling yawing of a vehicle having four or more wheels including four wheels located at each of front, rear, left and right, wherein the vehicle is one of the four wheels. The vehicle yawing control device includes at least one electric motor connected to the left and right driving wheels, and the vehicle yawing control device controls at least the electric motor to rotate the left and right front wheels out of the four wheels and the right and left front wheels. A yawing control device for a vehicle, comprising: a rotational speed difference control means for controlling a rotational speed difference from the rotational speed of the vehicle . When the rotation speed of the left and right front wheels is higher than that of the right front and rear wheels, the vehicle turns right, and when the rotation speed of the right and left front wheels is higher than that of the left front and rear wheels, it turns left. Exercise. In addition, the vehicle operating conditions such as vehicle speed and steering angle,
When the tire contact with the road surface is the same, such as the friction coefficient and slip condition of the road surface, the turning radius is smaller and the yaw rate is larger when the rotational speed difference between the left front wheel and the right front wheel is larger than when it is small. Become. At least one of the left and right front wheels and the left and right rear wheels of the four wheels is a left and right drive wheel. An electric motor is connected to the left and right drive wheels, and torque output by the electric motor is applied. As long as the other conditions are the same, the rotation speed becomes higher when the drive torque applied to the drive wheels is large than when it is low, and when the torque difference between the left and right drive wheels is large than when it is small. The difference in rotational speed between the left and right drive wheels becomes large. Of course, when a single electric motor is connected to each of the left and right driving wheels, a common electric motor is connected to the left and right driving wheels, and the electric motor is commonly connected through a differential device. The rotation speeds of the left and right drive wheels are not always the same. As the rotational speed of the left front wheel, the average value of the rotational speed of the left front wheel and the rotational speed of the left rear wheel, or the rotational speed of the representative wheel is used. The representative wheel is a wheel that has a great influence on the yawing of the vehicle. For example, a wheel to which a driving torque of an electric motor, a regenerative braking torque, or a braking torque of a friction braking device is positively applied, a wheel having a large supporting load, and a road surface. For example, a wheel that is in contact with a portion having a large friction coefficient. The same applies to the rotational speeds of the right and left front wheels. In any case, in this aspect, the rotational speed difference between the left front wheel and the right front wheel is controlled at least by the control of the electric motor. Since the electric motor has a smaller control delay than the internal combustion engine, good yawing control can be performed. A specific example of controlling the rotational speed difference between the left front wheel and the right front wheel will be described in paragraphs (2) and (4), but as described in paragraph (2), There are cases where the control is performed and cases where both the electric motor control and the friction braking device control are performed as described in the item (4).
In the vehicle yawing control device according to item (2), for example, if the torque applied to the left drive wheel and the torque applied to the right drive wheel is increased on one side and decreased on the other side, an increase and a decrease in torque occur almost simultaneously. Therefore, the accuracy of the yawing control itself can be improved. Further, it is possible to favorably avoid a temporary decrease in vehicle speed.
In the vehicle yawing control device according to the item (4), even when the drive torque is increased and the friction braking torque is also increased, the drive torque and the friction braking torque can be increased substantially at the same time. For,
It is possible to favorably avoid a decrease in vehicle speed. (2) The vehicle includes an electric motor connected to each of the left and right drive wheels of the four wheels, and the vehicle yawing control device is connected to each of the left and right drive wheels. Of the left and right drive wheels to increase the drive torque applied to the turning outer wheel or decrease the braking torque, and decrease the drive torque applied to the inner turning wheel. The vehicle yawing control device according to item (1), including left and right drive wheel torque difference control means for controlling the torque difference between the left and right drive wheels by either increasing the braking torque or increasing the braking torque . In the vehicle equipped with the vehicle yawing control device according to this section, at least one of the left drive wheel electric motor and the right drive wheel electric motor is controlled, so that the left drive wheel and the right drive wheel are separated from each other. The torque difference between them is controlled. Specific examples of the torque difference control include a mode in which the drive torque of one of the left drive wheel electric motor and the right drive wheel electric motor is increased and the other drive torque is decreased, and regenerative braking of one electric motor is performed. There is a mode in which the torque is increased and the regenerative braking torque of the other electric motor is decreased, a mode in which the output torque of one electric motor is used as the drive torque, and the output torque of the other electric motor is used as the regenerative braking torque. When the vehicle yawing control device described in this section is installed in a vehicle equipped with the friction braking device described in (4) and also controls the friction braking device, the electric drive for the left drive wheel is used. A mode in which the driving torque of either the motor or the electric motor for the right driving wheel is increased, and the friction braking torque applied to the driving wheel on the side opposite to the driving wheel whose driving torque is increased is also increased. There is also a mode in which the friction braking torque for the left and right drive wheels is increased by the same amount, and the drive torque for either the left wheel or the right wheel electric motor is increased.
The latter mode is effective when the friction braking torque applied to each of the left and right drive wheels cannot be controlled independently of each other in the friction braking device. When the above-mentioned aspects are compared, in the aspect of, both of the friction braking torque by the friction braking device and the drive torque by the electric motor are applied to one of the left and right drive wheels, but in the aspect of- Does not apply both braking torque and drive torque to one wheel. In any of the above aspects, the torque can be increased and decreased almost at the same time, so that the yawing control itself can be favorably performed and the reduction in vehicle speed can be favorably avoided. Also,
When increasing the torque applied to one drive wheel and decreasing the torque applied to the other drive wheel, compared to the case where only the torque applied to one drive wheel is increased or decreased, The amount of change in torque in the electric motor for obtaining the same amount of change in yawing moment can be reduced, and the amount of change in rotational speed in each drive wheel can be reduced. As a result, the yawing control can be performed while avoiding the deterioration of the braking slip state and the drive slip state due to the large change amount of the torque applied to the drive wheels. In other words, the amount of change in yawing moment can be increased without increasing the amount of change in output torque of the electric motor. Furthermore, if the increase amount and the decrease amount of the output torque are the same, it is possible to reduce the amount of change in the torque of the entire vehicle and the amount of change in the vehicle speed. (3) The left and right drive wheel torque difference control means increases the output torque of the electric motor connected to one of the left and right drive wheels and decreases the output torque of the electric motor connected to the other of the left and right drive wheels. The vehicle yawing control device according to item (2), further including a torque equal amount increasing / decreasing torque difference control means for controlling the electric motors connected to the left and right drive wheels so that and are approximately the same amount . When increasing the torque of one electric motor and decreasing the torque of the other electric motor, if the amount of increase and the amount of decrease are almost the same, the amount of change in the torque of the entire vehicle can be reduced and the speed change can be reduced. Can be small. The torque equal amount increasing / decreasing torque difference control means can also be referred to as equal torque increasing / decreasing means. (4) The vehicle includes four friction braking devices that frictionally engage a friction member with a brake rotating body that rotates with each of the four wheels to apply friction braking torque to the wheels. , The left and right drive wheels are connected via a differential device, and the rotation speed difference control means increases the drive torque of the electric motor and makes a turn of the left front wheel and the right front wheel. Friction for controlling the torque difference between the torque applied to the left and right front wheels and the torque applied to the right front wheel by increasing the pressing force of the friction member against the brake rotating body that rotates with at least one of the inner front and rear wheels. including brake rely left wheel torque difference control means (1) vehicle yaw control apparatus according to claim (claim 1). The driving torque of the electric motor is evenly applied to the left driving wheel and the right driving wheel, which are connected via the differential device, by 1/2. The drive torque applied to each of the left and right drive wheels has the same magnitude, and the amount of change in the drive torque of each of the left and right drive wheels that increases with an increase in the drive torque of the electric motor also has the same magnitude. On the other hand,
If the friction braking torque is increased by increasing the pressing force of the friction member against the brake rotating body of the wheel,
The torque of one of the left front wheel and the right front wheel to which the wheel whose friction braking torque is increased belongs is smaller than the torque of the wheel group on the opposite side. Therefore, if both the driving torque and the friction braking torque are increased, the torque difference between the left front wheel and the right front wheel can be controlled while satisfactorily avoiding the decrease in vehicle speed. Here, the wheels to which the friction braking torque is increased may be driving wheels or non-driving wheels. However, if the friction braking torque of the drive wheels is increased,
The advantage that the amount of change in the yawing moment can be increased while suppressing the deterioration of the braking slip state is obtained. The friction braking torque must be increased in order to obtain a large yawing moment change amount only by applying the friction braking torque. However, it is necessary to perform yawing control because the friction coefficient of the road surface is small, or because friction braking torque is applied for vehicle braking and a considerable braking slip has already occurred. In many cases, the frictional force is insufficient, and if the frictional braking torque is further increased from that state, the braking slip state may worsen due to excessive braking slip. On the other hand, if the friction braking torque of one of the left and right drive wheels is increased and the drive torque of both the left and right drive wheels is increased, a sufficient yawing moment change amount can be obtained without increasing the friction braking torque so much. be able to. Almost the same effect can be obtained by controlling the drive torque and the friction braking torque of the internal combustion engine, but the control torque of the internal combustion engine is poor, so the drive torque is increased after the increase of the hydraulic braking torque, and the electric drive torque is increased. It is not possible to perform yaw control as good as when the drive torque of the motor is used. In addition,
Even if the friction braking device is a hydraulic braking device that presses a friction member against a brake rotating body by hydraulic pressure, an electric motor,
It may be an electric braking device that presses the friction member against the brake rotating body by an electric drive device such as a laminated piezoelectric material. (5) The left and right wheel torque difference control means that relies on the friction braking,
A torque sum invariant type torque difference control means for controlling the torque difference so that the driving torque increase amount of the electric motor and the friction braking torque increase amount corresponding to the pressing force increase amount are substantially the same. A vehicle yawing control device according to claim (4) including claim (claim 2 ). If the drive torque increase amount and the friction braking torque increase amount are substantially the same, the change in vehicle speed can be avoided. (6) The vehicle yawing control device includes an actual yaw rate detection device that detects a yaw rate of the vehicle, a target yaw rate acquisition unit that acquires a target yaw rate based on a steering angle of a steering wheel of the vehicle, and the actual yaw rate detection device. When the absolute value of the difference between the detected actual yaw rate and the target yaw rate acquired by the target yaw rate acquisition means is equal to or greater than a set value, the actual yaw rate detected by the actual yaw rate detection device is calculated by the target yaw rate acquisition means. The vehicle yawing control device according to any one of items (1) to (5), including at least an electric motor control unit that controls the electric motor so as to approach the acquired target yaw rate . Although there are various modes of yawing control, the vehicle yawing control device described in this section can reduce the delay of the actual yaw rate from the target yaw rate. The actual yaw rate often lags the target yaw rate, but if the yawing control is performed by controlling the electric motor, it is easy to reduce the delay. The yawing control also includes vehicle stability control such as drift-out suppression control and spin suppression control that make the steering stability of the vehicle in a good state. (7) A vehicle yawing control device for controlling yawing of a vehicle including at least one electric motor connected to a left driving wheel and a right driving wheel among four wheels located in front, rear, left, and right, respectively. A vehicle yawing control device provided with electric motor control means for controlling at least one of the electric motors. By controlling the electric motor, the drive torque and the regenerative braking torque applied to the drive wheels connected to the electric motor can be controlled, and the yawing of the vehicle can be controlled. In the case of controlling the electric motor, the control delay can be reduced as compared with the case of controlling the internal combustion engine. The vehicle yawing control device according to this section is mounted on a vehicle equipped with an electric motor, but the vehicle may be a hybrid vehicle or an electric vehicle. (8) At least at least the yawing of a vehicle equipped with at least one electric motor connected to the left and right driving wheels of the four wheels located in the front, rear, left, and right
A vehicle yawing control method for controlling by controlling at least one of two electric motors.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A vehicle yawing control device according to an embodiment of the present invention will be described in detail below with reference to the drawings. As shown in FIG. 1, the vehicle equipped with the vehicle yawing control device is a hybrid vehicle, and front wheels 10 and 12 as drive wheels are driven by an electric drive device 14 and an internal combustion drive device (not shown). The electric drive device 14 includes a differential device 22, drive shafts 24, 26.
It is connected to the front wheels 10 and 12 via. The drive torque of the electric motor 28 is applied to the wheels 1 by the differential device 22.
It is evenly distributed to 0 and 12. The electric drive device 14 is
It is also a regenerative braking device that applies regenerative braking torque to the wheels 10 and 12 by regenerative braking of the electric motor 28. The vehicle is provided with a hydraulic braking device 30 as a friction braking device. A pad as a friction member is pressed against the rotor as a brake rotating body that rotates together with the wheels 10 and 12 by transmitting hydraulic pressure to the wheel cylinders 32 and 34, and hydraulic braking torque is applied to the wheels 10 and 12. Regenerative braking torque from the regenerative braking device 14 and hydraulic braking torque from the hydraulic braking device 30 are applied to the wheels 10 and 12 to suppress rotation.

The electric drive unit 14 is the electric motor 2 described above.
8, power storage device 36, transmission 38, power conversion device 4
0, an electric motor control device 42 and the like. The direct current stored in the power storage device 36 is converted into alternating current by the power conversion device 40 and supplied to the electric motor 28.
The power conversion device 40 includes an inverter and the like,
It is controlled by the electric motor control device 42. The magnitude of the drive torque of the electric motor 28 is controlled by current control such as slip frequency control and vector control in the inverter, and the drive torque applied to the wheels 10 and 12 is controlled. The electric motor control device 42 connects the power conversion device 40 to
The control is performed so that a drive torque having a magnitude corresponding to the operation state of the accelerator pedal 44 (see FIG. 2) is obtained, or is controlled based on information from the vehicle yawing control device 46, which will be described later. On the other hand, when the rotating shaft of the electric motor 28 is forcibly rotated by the wheels 10 and 12, the power storage device 36 is charged by the electromotive force generated in the electric motor 28. Becomes a load and regenerative braking torque is generated. The control of the regenerative braking torque is also performed by the power converter 40, similarly to the control of the drive torque. The magnitude of the regenerative braking torque is determined by the transmission 38
It can also be controlled by changing the gear position in.

The hydraulic braking device 30 includes the front wheels 10 and 12
In addition to the wheel cylinders 32 and 34, the linear valve devices 50 to 56, the wheel cylinders 64 and 66 of the rear wheels 60 and 62 shown in FIG. 2, the master cylinder 68, the constant hydraulic pressure source 70, and the like are included. The master cylinder 68 has two pressurizing chambers, and in each of these two pressurizing chambers, the same amount of hydraulic pressure is generated according to the operating force of the brake pedal 72. The liquid passage 74 is provided in one pressurizing chamber.
The wheel cylinders 32 and 34 of the front wheels 10 and 12, which are drive wheels, are connected to each other via the liquid passage 7 in the other pressurizing chamber.
Wheel cylinders 64, 6 of the rear wheels 60, 62 via
6 is connected.

The constant fluid pressure source 70 includes a master reservoir 78, a pump 80, an accumulator 82, etc. The hydraulic fluid in the master reservoir 78 is pumped up by the pump 80 and stored in the accumulator 82. Constant fluid pressure source 7
Two pressure switches 84 and 85 are provided at 0. One pressure switch detects that the hydraulic pressure stored in the accumulator 82 is out of the set range, and the electric motor 86 that drives the pump 80 is controlled so that the hydraulic pressure is kept in the set range. It The other pressure switch is a switch for detecting that the hydraulic pressure of the accumulator 82 becomes smaller than the lower limit value. When the hydraulic pressure of the accumulator becomes larger than the upper limit value, the hydraulic fluid is returned to the upper side of the pump 80 via the relief valve 88. In the accumulator 82, the working fluid within the set pressure range is constantly stored.

An electromagnetic opening / closing valve 90 is provided in the middle of the liquid passage 74.
Is provided, and by opening and closing this electromagnetic on-off valve 90,
The wheel cylinders 32 and 34 and the master cylinder 68 are communicated with each other or cut off from each other. When the regenerative braking cooperative control, antilock control, traction control, vehicle yawing control, etc. are performed, the electromagnetic opening / closing valve 90 is closed. An electromagnetic opening / closing valve 92 is provided between the wheel cylinder 32 and the wheel cylinder 34. By opening / closing the electromagnetic opening / closing valve 92, the wheel cylinder 3 is opened.
2, 34 may be connected or disconnected from each other.
When the hydraulic pressures of the wheel cylinders 32 and 34 are controlled separately, the electromagnetic opening / closing valve 92 is closed. Liquid passage 76
Similarly, an electromagnetic opening / closing valve 94 for connecting or disconnecting the wheel cylinders 64 and 66 and the master cylinder 68 is provided, and the wheel cylinder 64 is also provided.
An electromagnetic opening / closing valve 96 is provided for connecting and disconnecting the wheel cylinder 66 and the wheel cylinder 66. In the present embodiment, the wheel cylinders 64, 66 of the rear wheels 60, 62
Can be controlled separately.

The constant fluid pressure source 70 and the master reservoir 78
And the respective wheel cylinders 32, 34, 64, 66 are provided with the linear valve devices 50 to 56, respectively. The linear valve devices 50 to 56 will be described later, but by the control of the linear valve devices 50 to 56,
The hydraulic pressure of each wheel cylinder 32, 34, 64, 66 can be controlled independently. Further, an electromagnetic opening / closing valve 98 is provided between the wheel cylinders 32, 34 of the front wheels 10, 12 and the wheel cylinders 64, 66 of the rear wheels 60, 62, and the hydraulic pressure of the wheel cylinders 32, 34 of the front wheels 10, 12 is provided. To control the wheel cylinders 64 of the rear wheels 60, 62,
When 66 is communicated with the master cylinder 68, it is switched to the closed state when a failure occurs in the electric system.

A pressure increasing device 102 is provided between the master cylinder 68, the constant hydraulic pressure source 70, the master reservoir 78, and the wheel cylinders 32 and 34. Booster 102
Includes a mechanical pressure increasing valve, and due to a failure of the vehicle yaw rate control device 46, the constant hydraulic pressure source 70, etc.,
When the hydraulic pressure of the constant hydraulic pressure source 70 becomes lower than the hydraulic pressure of the master cylinder 68, the working fluid of the master cylinder 68 is pressurized and supplied to the wheel cylinders 32 and 34. A stroke simulator 104 is provided between the brake pedal 72 and the master cylinder 68,
It is possible to avoid a feeling of strangeness when the brake pedal 72 is depressed.

The hydraulic braking device 30 includes a master cylinder 6
A hydraulic pressure sensor 110 for detecting the hydraulic pressure of No. 8 and hydraulic pressure sensors 112 to 118 for detecting the hydraulic pressure of each of the wheel cylinders 32, 34, 64, 66 are provided. As will be described later, the hydraulic pressure of the master cylinder 68 has a magnitude corresponding to the braking torque intended by the driver, so the hydraulic pressure sensor 110
The target braking torque can be the braking torque corresponding to the hydraulic pressure detected by. Also, each wheel 10, 1
Wheel speed sensor 12 for detecting wheel speeds of 2, 60, 62
0 to 126 are provided, and the slip state of each wheel can be detected in antilock control and traction control.
The vehicle equipped with the vehicle yawing control device 46 according to the present embodiment includes a yaw rate sensor 130 for detecting a yaw rate of the vehicle, an accelerator operation amount sensor 134 for detecting an operation amount as an operation state of the accelerator pedal 44, and a steering wheel 136. A steering angle sensor 138 for detecting the steering angle of the vehicle is provided, and each of these sensors is connected to the input section of the vehicle yawing control device 46.

Next, the linear valve devices 50 to 56 will be described with reference to FIG. Since the linear valve devices 50 to 56 have the same structure, only the linear valve device 50 will be described, and description of the other linear valve devices will be omitted. The linear valve device 50 is
It includes a pressure increasing linear valve 150 as a pressure increasing control valve and a pressure reducing linear valve 152 as a pressure reducing control valve. The pressure increasing linear valve 150 is provided in the middle of the liquid passage 158 connecting the constant hydraulic pressure source 70 and the wheel cylinder 32, and the pressure reducing linear valve 152 is provided in the middle of the liquid passage 160 connecting the master reservoir 78 and the wheel cylinder 32. It is provided.

The pressure increasing linear valve 150 includes a seating valve 190 and an electromagnetic urging device 194.
The seating valve 190 includes a valve body 200 and a valve seat 202.
And the electromagnetically biased body 204 that moves integrally with the valve body 200
And a spring 206 that biases the electromagnetically biased body 204 in a direction in which the valve body 200 is seated on the valve seat 202. The electromagnetic biasing device 194 holds the solenoid 210 and the solenoid 210. Resin holding member 212
The first magnetic path forming body 214 and the second magnetic path forming body 216 are included. When a voltage is applied across the winding of the solenoid 210, a current flows through the winding of the solenoid 210 and a magnetic field is formed. When the voltage applied to the winding of the solenoid 210 is changed, the magnetic force acting between the electromagnetically biased body 204 and the second magnetic path forming body 216 is changed.
A fitting projection 220 is formed on the end surface of the electromagnetically biased body 204 on the second magnetic path forming body 216 side, and on the end surface of the second magnetic path forming body 216 on the electromagnetic biased body 204 side. A fitting hole 222 is formed so as to be fitted in the fitting projection 220 in a state of being relatively movable in the axial direction. The spring 206 is attached to the fitting hole 222.

When a voltage is applied to the solenoid 210,
Solenoid 210, first magnetic path forming body 214, electromagnetically biased body 204, second magnetic path forming body 216, first magnetic path forming body 21
4, a magnetic path passing through the solenoid 210 is formed, but the magnetic resistance between the electromagnetically-biased body 204 and the second magnetic-path-forming body 216 is the magnetic resistance between the electromagnetically-biased body 204 and the second magnetic-path-forming body 216. It changes depending on the relative axial position of and. Specifically, if the relative position in the axial direction between the electromagnetically biased body 204 and the second magnetic path forming body 216 changes, the fitting protrusion 220 of the electromagnetically biased body 204 and the second magnetic path forming body are formed. Cylindrical surfaces (fitting protrusion 2
The areas of the outer peripheral surface of 20 and the inner peripheral surface of the fitting hole 222 facing each other) change. If the electromagnetically biased body 2
04 and the second magnetic path forming member 216 are simply opposed to each other with their end faces being slightly spaced apart from each other, the electromagnetically biased member 2
04 and the second magnetic path forming member 216 in the axial direction,
That is, the magnetic resistance is acceleratedly reduced with the approach, and the magnetic force acting between the two is acceleratedly increased. On the other hand, in the pressure-increasing linear valve 150 of the present embodiment, as the electromagnetically biased body 204 and the second magnetic path forming body 216 approach, the cylinder of the fitting protrusion 220 and the fitting hole 222 becomes larger. While the area of the surface increases and the magnetic flux passing through this cylindrical surface increases, the end surface of the electromagnetically biased body 204 and the second magnetic path forming body 21.
The magnetic flux passing through the air gap with the end face of 6 is reduced. As a result, if the voltage applied to the solenoid 210 is constant, the magnetic force that biases the electromagnetically biased body 204 toward the second magnetic path forming body 216 is the same as the electromagnetically biased body 204 and the second magnetic path. It becomes almost constant regardless of the relative movement in the axial direction with respect to the forming body 216. On the other hand, the electromagnetically biased body 2 by the spring 206
The biasing force that biases 04 in the direction away from the second magnetic path forming body 216 is the electromagnetically biased body 204 and the second magnetic path forming body 21.
It increases with the approach of 6. Therefore, the valve 200
In a state in which the biasing force based on the hydraulic pressure is not applied, the movement of the electromagnetically biased member 204 in the direction of the second magnetic path forming member 216 becomes equal to the biasing force of the spring 206 and the magnetic force. It will be stopped.

The magnitude of the magnetic force acting in the direction of moving the electromagnetically biased body 204 toward the second magnetic path forming body 216 increases with the magnitude of the voltage applied to the winding of the solenoid 210, The relationship between the applied voltage and the magnetic force can be known in advance. Therefore, by continuously changing the applied voltage according to the relationship, the force for urging the electromagnetically urged body 204 can be arbitrarily changed. When the applied voltage is increased, the magnetic force is increased and the valve 20
The force in the direction of pressing 0 to the valve seat 202 becomes small, and the valve 200 easily separates from the valve seat 202. Valve body 200
The biasing force due to the differential pressure of the hydraulic fluid acting on the electromagnetic force is the force (magnetic force and the biasing force of the spring 206 that acts on the electromagnetically biased body 204. If the force is larger than the force (opposite direction), they are separated, and the valve opening pressure becomes smaller when the applied voltage is increased. Pressure reducing linear valve 1
52 is also basically the same as the pressure-increasing linear valve 150, and the differential pressure acting force according to the hydraulic pressure difference before and after the pressure-decreasing linear valve 152 is the magnetic force according to the applied voltage and the urging force of the spring 224. If it becomes larger than the total force of
Are separated from the valve seat 202.

In the present embodiment, the opening pressure of the pressure-increasing linear valve 150 when the applied voltage is 0 is about 20M.
Pa (about 204 kgf / cm ² ) and the opening pressure of the pressure reducing linear valve 152 is 18 MPa (≈184 kgf / c).
m ² ), and in each case, it is set higher than the maximum hydraulic pressure of the hydraulic fluid supplied by the constant hydraulic pressure source 70.
The maximum hydraulic pressure of the hydraulic fluid supplied to the pressure increasing linear valve 150 and the pressure reducing linear valve 152 is the maximum hydraulic pressure supplied by the pump 80 and stored in the accumulator 82. Therefore, when the voltage is not applied to the solenoid 210, the hydraulic fluid of the constant hydraulic pressure source 70 is caused to flow into the wheel cylinder via the pressure-increasing linear valve 150,
It is virtually prevented from flowing out to the master reservoir 78 via the pressure reducing linear valve 152.

Solenoid 21 of boosting linear valve 150
When the voltage applied to 0 is increased and the valve opening pressure is decreased, the high pressure hydraulic fluid from the constant hydraulic pressure source 70 is caused to flow into the wheel cylinder 32, and the hydraulic pressure is increased. When the voltage applied to the solenoid 210 of the pressure reducing linear valve 152 is increased and the valve opening pressure is decreased, the hydraulic fluid in the wheel cylinder 32 is caused to flow out to the master reservoir 78, and the hydraulic pressure is reduced. As described above, the hydraulic pressure of the wheel cylinder 32 can be controlled by controlling the voltage applied to the solenoid 210 of either the pressure increasing linear valve 150 or the pressure reducing linear valve 152 of the linear valve device 50. In the present specification,
This voltage is abbreviated as the control voltage of the linear valve device 50.

The vehicle yawing control device 46 and the electric motor control device 42 are mainly composed of a computer having a ROM, a RAM, a PU (processing unit) and the like. The hydraulic pressure sensors 110 to 118 and the wheel speed sensor 120 described above are provided at the input portion of the vehicle yawing control device 46.
To 126, yaw rate sensor 130, accelerator operation amount sensor 134, steering angle sensor 138, etc., the electric motor 2
Encoder 260 for detecting the rotation speed of No. 8 and power storage device 3
6 is connected to a charge capacity detection device 262 for detecting the charge capacity, and the output unit includes the electric motor control device 42, solenoids of the electromagnetic opening / closing valves 90, 92, 94, 96, and linear valve devices 50 to 56. The solenoid 210 and the like are connected via a drive circuit (not shown). The ROM includes a total braking torque control program, a vehicle yawing control program represented by the flowchart of FIG. 6, various programs including an anti-lock control program, a traction control program, etc. Etc. are stored.

The encoder 260, the accelerator operation amount sensor 134, etc. are connected to the input portion of the electric motor control device 42, and the vehicle yawing control device 4 is connected to the output portion.
6, the power converter 40 and the like are connected. Although not shown in the flow chart, various programs such as a drive torque control program and a regenerative braking torque control program are stored in the ROM. The electric power conversion device 40 is controlled so as to obtain a drive torque having a magnitude based on the depression state of the accelerator pedal 44, or has a drive torque or a regenerative braking that is substantially the same as the drive torque target value and the regenerative braking torque target value. It is controlled so that torque can be obtained.

Information is exchanged between the electric motor control device 42 and the vehicle yawing control device 46. The vehicle yawing control device 46 supplies the electric motor control device 42 with information indicating a regenerative braking torque target value during regenerative braking cooperative control, antilock control, etc., and information indicating a drive torque target value during vehicle yawing control. Then, the electric motor control device 42 is supplied to the vehicle yawing control device 46 with information representing the actual regenerative braking torque value. In the electric motor control device 42,
The actual regenerative braking torque and the actual driving torque are obtained based on the number of revolutions of the electric motor 28, and information representing each of them is supplied to the vehicle yawing control device 46. Further, the vehicle yawing control device 46 includes an electric motor 28.
Is also supplied, the power generation side upper limit value, which will be described later, is acquired based on this rotation speed, and the regenerative braking torque target value is determined.

In the regenerative braking cooperative control, with respect to the front wheels 10 and 12 as the driving wheels, the electric power converter is arranged so that the total braking torque, which is the sum of the regenerative braking torque and the hydraulic braking torque, becomes the target total braking torque. 40 and linear valve devices 50, 52 are controlled. The target total braking torque is a braking torque according to the driver's intention, and the hydraulic pressure sensor 11
It is determined based on the hydraulic pressure of the master cylinder 68 detected by 0. The regenerative braking torque target value is determined as the maximum energy efficiency upper limit value, and the hydraulic braking torque target value is determined as the magnitude obtained by subtracting the actual regenerative braking torque from the target total braking torque. Here, the maximum energy efficiency upper limit value is the upper limit value on the power generation side which is the upper limit value of the regenerative braking torque determined by the convenience of the power generation side such as the rotation speed of the electric motor 28 functioning as a generator, the charging capacity of the power storage device 38, and the temperature. The upper limit value of the electricity storage side, which is the upper limit value determined by the convenience of the equal electricity storage side, and the upper limit value of the operation side determined according to the operating force of the brake pedal 72 by the driver (the upper limit value of the operation side corresponds to the target total braking torque described above) ) And the minimum upper limit value, that is, the upper limit value as long as the target total braking torque is not exceeded. If the regenerative braking torque target value is determined to be the energy efficiency maximum upper limit value, it is possible to suppress wasteful release of the kinetic energy of the wheels. In the regenerative braking cooperative control, the hydraulic pressure corresponding to the hydraulic braking torque target value and the wheel cylinders 32 and 34 detected by the hydraulic pressure sensors 112 and 114 in the state where the electromagnetic opening / closing valve 90 is switched to the closed state. The control voltage of the linear valve devices 50 and 52 is determined so that the difference with the hydraulic pressure becomes small.

At the time of antilock control, the solenoid opening / closing valve 9
By controlling the linear valve devices 50 to 56 in a state in which 0, 94 are switched to the closed state, each wheel 10, 12, 60, 62 is maintained so that the braking slip state of each wheel is maintained in an appropriate state. Cylinders 32, 34, 6
The hydraulic pressure of 4,66 is controlled. As in the case described above, the wheel cylinders 32, 34 and the wheel cylinder 6
When it is necessary to control the hydraulic pressure of 4, 66 independently,
The electromagnetic on-off valves 92 and 96 are also switched to the closed state. When the anti-lock control is performed on the front wheel side and not on the rear wheel side, the electromagnetic opening / closing valve 94 is switched to the open state and the electromagnetic opening / closing valve 98 is switched to the closed state. During the antilock control, not only the hydraulic braking torque but also the regenerative braking torque can be applied to the drive wheels 10 and 12. In this case, the total braking torque is controlled so that the braking slip state of the drive wheels 10 and 12 is maintained in a substantially proper state. Even if the hydraulic braking torque is controlled with the regenerative braking torque maintained at a substantially constant level, or if the regenerative braking torque is controlled with the hydraulic braking torque maintained at a substantially constant level, both You may control.

At the time of traction control, the solenoid valves 90 provided on the front wheels 10 and 12 as driving wheels are closed and the solenoid valve 98 is closed, whereby the wheel cylinders 32 and 34 are closed. The linear valve device 5 is cut off from the master cylinder 68.
The hydraulic pressure of the wheel cylinders 32 and 34 is controlled by the control of 0 and 52 so that the drive slip state is maintained in an appropriate state. When the drive slip states of the front wheels 10 and 12 are independently controlled, the electromagnetic opening / closing valve 92 is also switched to the closed state. The solenoid on-off valve 94 is kept open and the rear wheel 6
The 0, 62 wheel cylinders 64, 66 are kept in communication with the master cylinder 68.

In the present embodiment, the vehicle yawing control is a control for bringing the actual yaw rate ωr close to the target yaw rate ωt, and the actual yaw rate ωr and the target yaw rate ωt
It is performed when the absolute value of the difference between and becomes larger than the set value. The drive torque is increased by the control of the electric motor 28, and the wheel cylinder hydraulic pressure of either one of the left and right front wheels 12, 10 is increased by the control of either one of the linear valve devices 50, 52, so that the hydraulic braking torque is increased. Is increased. As a result, the difference between the rotational speeds of the left and right front wheels 12, 10 becomes large, and the torque difference becomes large.

For example, when the actual yaw rate ωr is smaller than the target yaw rate ωt by a set value or more, and the difference between them becomes larger than the set value, as shown in FIG. 4, as shown in FIG. The hydraulic braking torque of the left front wheel 12 is the inner wheel when turning (while the vehicle is turning left), while the drive torque transmitted to the front wheels 10 and 12 is increased. In the turning inner wheel 12, both the hydraulic braking torque and the driving torque are increased, and in the turning outer wheel 10, only the driving torque is increased. Further, the increased amount of hydraulic braking torque and the increased amount of driving torque are substantially the same. As a result, the rotational speed of the turning inner wheel 12 is decreased, whereas the rotational speed of the turning outer wheel 10 is increased, thereby increasing the rotational speed difference and increasing the torque difference between them. . The left yaw rate of the vehicle is increased, and it becomes possible to bring the actual yaw rate ωr close to the target yaw rate ωt. Further, since the drive torque is increased by controlling the electric motor 28 instead of the engine, the response delay can be reduced. The driving torque and the hydraulic braking torque can be increased almost at the same time, and the decrease in the traveling speed of the vehicle can be suppressed. Since the increase amount of the driving torque and the increase amount of the hydraulic braking torque are substantially the same, it is possible to suppress the change in the vehicle speed due to the vehicle yawing control.

The left front wheel 12 and the left rear wheel 6 which are inside the turn
The average value of the rotational speeds of the left and right left front wheels (turning inner front and rear wheels) 12, 62 includes the rotational speeds of the right front and rear wheels (turning outer front and rear wheels) that include the right front wheel 10 and the right rear wheel 62 that are turning outer sides. It is made smaller than the average value. In other words, the driving torque applied to each of the front and rear wheels 12, 62 on the inside of the turn,
The sum considering the sign of the braking torque is the front and rear wheels 1 on the outside of the turn.
It is smaller than the sum of the driving torque and the braking torque of 0 and 60. Here, the torque change amount changed in the turning inner front and rear wheels 12, 62 and the turning outer front and rear wheels 1
The torque change amount changed at 0 and 60 is almost the same. The driving torque and the braking torque are increased when the driving torque and the braking torque (at least one of the hydraulic braking torque and the regenerative braking torque) are already applied when the vehicle yawing control is started. Because there is. When neither the brake pedal 72 nor the accelerator pedal 44 is operated, these drive torque and hydraulic braking torque are newly added. Regarding the hydraulic braking torque, even if the turning inner wheel 12 on the front wheel side is increased, the turning inner wheel 6 on the rear wheel side is increased.
May be increased in 2.

The magnitudes of the hydraulic braking torque and the driving torque which are increased in the drive wheels 10 and 12 are determined as shown in FIG. In the figure, the drive torque Td and the hydraulic braking torque T increased in the vehicle yawing control are shown.
b, that is, the newly added torque in the vehicle yawing control is described, and the braking torque Tbrc or the operation amount of the accelerator pedal 44 corresponding to the operation amount of the brake pedal 72 that has been already applied when the vehicle yawing control is started. The description of the driving torque Tdacc according to the above is omitted. The braking torque Tbrc is not limited to the hydraulic braking torque,
The regenerative braking torque may include both the hydraulic braking torque and the regenerative braking torque.

The hydraulic braking torque Tb is applied to the turning inner wheel 12, and the driving torque Td is transmitted to the left and right driving wheels 10 and 12 by 1/2 through the differential device 22. Further, the distance from the center O of the vehicle to the ground contact point of the driving wheels 10 and 12 with respect to the road surface of the tire is represented as a distance R, and is defined by a straight line extending in the front-rear direction of the vehicle and a straight line connecting the ground contact point of the tire and the center O. The angle formed is represented as an angle β. In this case, the yawing moment T increased about the vertical axis passing through the center O
c is given by the equation Tc = R · sin β · (Td / 2r) + R · sin β · (Tb / 2r) · (1). Here, r is the radius of the tire, and (Td
/ 2r) is the driving torque Td applied to the right front wheel 10.
/ F which increases due to the addition of / 2
d and the term represented by (Tb / 2r) is the left front wheel 12
Is the ground contact force (Fb-Fd) of the tire which is increased by the addition of the braking torque Tb and the driving torque Td / 2 (Tb-Td / 2 = Tb / 2).

Further, the yawing moment Tc increased about the vertical axis passing through the center O can be expressed as Tc = Izω' (2) by using the rotational inertia moment Iz of the vehicle. Here, ω'is the rotational acceleration about the vertical axis. Therefore, from the above equations (1) and (2), R · sin β · (Td / 2 + Tb / 2) / r = Iz · ω ′ ·· (3) holds, but as described above, the driving torque is Since Td and hydraulic braking torque Tb are equal, if we summarize using drive torque Td, equation (3) can be rewritten as equation R · sin β · Td / r = Iz · ω ′ ·· (4). From this equation (4), it is clear that the driving torque Td can be obtained according to the equation Td = Izω'r / (Rsin β)  (5).

Further, the angular acceleration ω'can be expressed by the equation ω '= kΔω using the difference Δω between the target yaw rate ωt and the actual yaw rate ωr and the control constant k. Substituting this into equation (5) gives: Td = Iz · k · Δω · r / (R · sin β) ··· (6). Rewriting equation (6) gives the driving torque Td
Can be expressed by the equation Td = K1..DELTA..omega .. (7). Here, K1 is a control gain and is a constant represented by K1 = Iz.k.r / (R.sin .beta.).

The drive torque Td and the hydraulic braking torque Tb thus increased in the yawing control of the vehicle.
Is determined. At the beginning of vehicle yawing control,
When neither the accelerator pedal 44 nor the brake pedal 72 is operated, the drive torque Td and the hydraulic braking torque Tb are the same as the output torque Tm of the electric motor 28.
(= Td), hydraulic braking torque Ti applied to the turning inner wheel 12
(= Tb). Here, the hydraulic braking torque To applied to the turning outer wheel 10 is zero. When either one of the accelerator pedal 44 and the brake pedal 72 is operated, it is determined in consideration of the driving torque Tdacc and the braking torque Tbrc which have already been applied according to these operation amounts. When the accelerator pedal 44 is depressed, the drive torque Tm is determined as the sum (Td + Tdacc) of the drive torque applied during yawing control and the drive torque corresponding to the operation amount of the accelerator pedal 44, and the brake pedal 72 When is depressed, the braking torque Ti applied to the turning inner wheel is determined as the sum (Tb + Tbrc) of the braking torque applied during yawing control and the braking torque corresponding to the operation amount of the brake pedal 72,
The braking torque To applied to the turning outer wheel is determined to be only the braking torque (Tbrc) according to the operation amount. Electric motor 2
8 is controlled so that the driving torque Tm is output, and the necessary braking torque is added as hydraulic braking torque. If the regenerative braking torque is applied at the start of the yawing control, the regenerative braking torque is added as the hydraulic braking torque.

The vehicle yawing control is performed according to the execution of the vehicle yawing control program represented by the flowchart of FIG. In S10, the target yaw rate ωt is obtained based on the steering angle θ of the steering wheel 136. The target yaw rate ωt is obtained by, for example, the formula ωt = v · sin (θ / N) · K2 / L. Here, v is the vehicle body speed, and N is the steering gear ratio. L is the wheelbase,
In this embodiment, it can be represented by 2Rcos β. The coefficient K2 is a value that changes according to the road surface μ and is increased as the road surface μ increases. Next, in S11, the actual yaw rate ωr is detected based on the output signal of the yaw rate sensor 130, and in S12, the absolute value Δω of the difference between the target yaw rate ωt and the actual yaw rate ωr is obtained. At S13, the yaw rate difference Δω is equal to the set value K.
It is determined whether or not it is larger than 3, and if it is larger, S1
The vehicle yawing control is performed as described above after 4 and is not performed when the value is less than or equal to the set value.

At S14, the drive torque Td applied in the vehicle yawing control is obtained according to the above equation (7). Further, the hydraulic braking torque Tb is the driving torque T
It has the same size as d. Next, in S15, the operation states of the brake pedal 72 and the accelerator pedal 44 are detected. Whether or not the brake pedal 72 is depressed is detected based on the output signal of the hydraulic pressure sensor 110,
Whether or not the accelerator pedal 44 is depressed is detected based on the output signal of the accelerator operation amount sensor 134. When the brake pedal 72 is depressed,
When the master cylinder hydraulic pressure becomes larger than 0 and the accelerator pedal 44 is depressed, the accelerator operation amount becomes larger than 0. As described above, in the present embodiment, the hydraulic pressure sensor 110 and the accelerator operating force sensor 134 also serve as the brake switch and the accelerator switch, but they may be provided separately. S1
As described above, the drive torque Tm output by the electric motor 28 and the turning inner wheel 1 are determined according to the detection result of No. 5 in FIG.
2, hydraulic braking torques Ti and T applied to each outer ring 10
Each o is decided.

When it is determined that the brake pedal 72 is depressed and the accelerator pedal 44 is not depressed, the hydraulic braking torque Ti of the turning inner wheel 12 is determined in accordance with the operation amount of the brake pedal 72 in S16 and S17. Is determined as the sum of the hydraulic braking torque Tbrc and the hydraulic braking torque Tb necessary for yawing control, and the hydraulic braking torque To of the outer turning wheel 10 is the hydraulic braking torque according to the operation amount of the brake pedal 72. Tbrc. The output torque Tm of the electric motor 28 is determined as the drive torque Td required for yawing control. The accelerator pedal 44 is depressed,
When it is determined that the brake pedal 72 is not depressed, the hydraulic braking torque Ti of the turning inner wheel 12 is determined as the hydraulic braking torque Tb in S18 and 19, and the hydraulic braking torque To of the turning outer wheel 10 is determined. It is determined to be 0. The output torque Tm of the electric motor 28 is determined as the sum of the drive torque Td required for yawing control and the drive torque Tdacc according to the operation amount of the accelerator pedal 44. When neither the brake pedal 72 nor the accelerator pedal 44 is depressed, the hydraulic braking torque Ti is determined in S20 and S21.
Is determined as the hydraulic braking torque Tb and the hydraulic braking torque To is 0, and the output torque Tm of the electric motor 28 is
The driving torque Td is determined. In the yawing control in this embodiment, the same is true when the actual yaw rate ωr is larger than the target yaw rate ωt by a set value or more. In this case, the hydraulic braking torque and the driving torque are increased for the outer turning wheel 10, and the driving torque is increased for the inner turning wheel.

As described above, in the present embodiment, in the control in which the hydraulic braking torque and the driving torque are added so that the actual yaw rate ωr approaches the target yaw rate ωt,
The driving torque is not the driving torque of the internal combustion engine, but the electric motor 2
The driving torque is 8. Therefore, compared with the case where the drive torque is controlled by the control of the internal combustion engine, the responsiveness is improved, and the drive torque can be increased almost simultaneously with the hydraulic braking torque. Moreover, since the increased hydraulic braking torque and drive torque have substantially the same magnitude, it is possible to favorably avoid a change in vehicle speed during vehicle yawing control. Further, there is also an advantage that a large yawing moment can be generated in order to positively bring the actual yaw rate ωr close to the target yaw rate ωt. In order to increase the yawing moment, it is necessary to increase the amount of increase in braking torque. However, when the yawing control is required, the steering stability of the vehicle is not good in many cases, such as the friction coefficient of the road surface is small or a considerably large braking torque is already applied. Here, if the increase amount of the braking torque is increased, the braking slip state may be deteriorated due to the increase. If the driving torque is increased, the possibility that the braking slip state is deteriorated is small, but if the delay of the increase in the driving torque with respect to the increase in the hydraulic braking torque is large, then again,
Therefore, the braking slip condition may deteriorate. On the other hand, if the increase in the driving torque and the increase in the hydraulic braking torque occur almost at the same time, the driving torque can be increased even if the increase amount of the hydraulic braking torque is increased, so that the braking slip state is deteriorated. It is possible to avoid it satisfactorily. Therefore, it is possible to positively increase the hydraulic braking torque and increase the amount of increase in the yawing moment, and positively bring the actual yaw rate ωr close to the target yaw rate ωt.

Further, since the hydraulic braking torque is applied to the drive wheels, the delay of the actual yaw rate ωr from the target yaw rate ωt can be reduced. Electric motor 2
Since 8 is connected to the propeller shafts 26 and 24 of the left and right drive wheels 12 and 10 via the differential device 22, the drive torque of the electric motor 28 is equally transmitted to the turning inner wheel 12 and the outer wheel 10. Since the hydraulic braking torque is increased in the inner wheel 12, the rotation speed of the turning inner wheel 12 is reduced. As a result, the rotation speed of the turning outer wheel 10 increases, and the rotation speed difference increases. Here, in the yawing control, the same effect is produced even when the drive torque is constant, but in the present embodiment, the drive torque is quickly applied, so that the rotational speed difference can be rapidly increased.

Further, according to the vehicle yawing control device in the above embodiment, in addition to yawing control for making the actual yaw rate ωr close to the target yaw rate ωt, drift out suppression control and spin suppression control can also be performed. In this case, it is estimated whether the running state of the vehicle is in the spin state or in the drift out state,
When it is estimated that the spin state is in effect, the spin suppression control is performed, and when it is estimated that the drift out state is in effect, the drift out suppression control is performed.

In the spin suppression control, the drive wheels 10,
The hydraulic braking torque of the turning outer wheel out of 12 is increased, and both drive wheels 1 are controlled by the electric motor 28.
The drive torque of 0, 12 is increased. In the drift-out suppressing control, the hydraulic braking torque with the turning inner wheel of the non-driving wheels 60 and 62 is increased, and
By controlling the electric motor 28, the drive torque of both drive wheels 10, 12 is increased. Since the delay of the increase of the driving torque with respect to the increase of the hydraulic braking torque can be reduced, it is possible to suppress the decrease in the traveling speed of the vehicle. The sum of the rotational speeds of the front and rear wheels 12 and 62 on the inside of the turn is the front and rear wheels 10 on the outside of the turn.
It is smaller than the sum of the rotational speeds of 60, and the front and rear wheels 1 inside the turning
The sum of the torques of 2, 62 is made smaller than the sum of the torques of the front and rear wheels 10, 60 on the outside of the turn. When the drift-out suppression control is performed, it is common to generate a yawing moment in the same direction as the turning direction and to reduce the vehicle speed, but it is not essential to reduce the vehicle speed, and a constant vehicle speed is required. It can be done in a state where

As described above, in the present embodiment, the vehicle yawing control device includes the vehicle yawing control device 46 mainly composed of the computer and the yaw rate sensor 13.
0, the steering angle sensor 134, and the like. The rotational speed difference control means is constituted by the portion that executes S14 to S21 of the vehicle yawing control device, and the rotational speed difference control means includes the left and right driving wheel torque difference control means and the friction braking-based left and right wheel torque difference control means. But also.

In the above-described embodiment, the target yaw rate ωt is set to have a size corresponding to the road surface μ, but it is not essential to have a size corresponding to the road surface μ, and the target yaw rate ωt can be obtained based on another arithmetic expression. You can For example, the vehicle speed V and the stability factor Kh may be used to obtain the value according to the expression ωr = (V * θ) / {(1 + Kh * V ² ) * N * L}. In the above embodiment, the vehicle yawing control device 46 determines both the hydraulic braking torque target value and the drive torque target value, but the drive torque target value is determined by the electric motor control device 4.
It can also be made to be decided in 2. Further, the control of the regenerative braking torque and the hydraulic braking torque in the regenerative braking cooperative control is an example, and the control may be performed in other modes. Further, the vehicle yawing control device 46 is connected to the electric motor control device 42 by the electric motor 2
Although the information indicating the output torque target value of 8 is supplied, the information indicating the change amount of the output torque may be supplied.

Further, in the above-described embodiment, when the vehicle yawing control is performed when the brake pedal 72 is depressed, the braking torque applied without delay at the time when the yawing control is started is changed to the liquid level. The pressure braking torque is applied to the wheels, but it may be applied as the regenerative braking torque. In that case, in the execution of S16 and 17, the output torque of the electric motor 28 is set to torque Tm = Td + Tbrc, and the hydraulic control torques of the turning inner wheel 12 and the turning outer wheel 10 are torques Ti = Tb and To, respectively. = 0. Further, in the above-described embodiment, the vehicle yawing control is performed even when the brake pedal 72 or the accelerator pedal 44 is depressed, but when the brake pedal 72 or the accelerator pedal 44 is depressed, You can choose not to do it. Further, although the hydraulic braking device is provided as the friction braking device, the invention is not limited to the hydraulic braking device, and may be an electric braking device that presses the friction member against the brake rotating body by an electric drive device such as an electric motor or a laminated piezoelectric body. Good. Further, not only the hydraulic braking device but also braking devices other than the electric braking device and the friction braking device may be included.

Further, although the linear valve devices 50 to 56 are provided for each wheel cylinder 32, 34, 64, 66, it is not essential to provide them for each wheel cylinder, and the wheel cylinders for the rear wheels 60, 62 are not provided. When the hydraulic pressure is commonly controlled, the linear valve device can be commonly used, and in that case, the cost of the device can be reduced. Further, a linear valve device may be provided commonly to the four wheel cylinders, and a plurality of solenoid valves may be provided for each wheel cylinder. When the regenerative braking cooperative control is performed, it is common that each wheel cylinder hydraulic pressure is controlled to the same magnitude, so the linear valve device is controlled, antilock control, traction control, vehicle yawing control, etc. If is done, the solenoid valve can be controlled. The solenoid valve is preferably provided between the wheel cylinder and the constant hydraulic pressure source 70 and between the wheel cylinder and the master reservoir 78.

Further, the electric driving device 14 is not limited to the ones in the above-mentioned respective embodiments, but may be the electric driving device 280 shown in FIG. 7, for example. In the electric drive device 280, the electric motor 28 is provided for each of the wheels 10 and 12.
2, 284 are provided, and electric power converters 285, 286 and transmissions 288, 289 are provided for each of the electric motors 282, 284. If the electric motors 282, 284 are provided for the wheels 10, 12 respectively, the drive shafts 24, 2
6. There is also an advantage that the differential device 22 and the like are unnecessary. Here, if the brake is a drum brake, the electric motor can be arranged inside the drum, and space can be saved. In addition, the drive torque and the braking torque applied to each wheel 10, 12 are calculated by the electric motor 28.
By controlling 2,284, it is possible to control each separately.

An example of control in this embodiment will be described based on the flowchart shown in FIG. Steps S10 to 15 are the same as the flowchart shown in FIG. After S31, the electric motor 282 is operated based on the operation states of the brake pedal 72 and the accelerator pedal 44.
The torque applied to the drive wheels 10 and 12 is determined by the control of 284, but for ease of explanation, it is assumed that the vehicle is also turning left in this embodiment. When it is determined that the brake pedal 72 is depressed, the output torque of the electric motor 284 provided corresponding to the turning inner wheel 12 is Tim = (T
brc + Tb / 2), and the output torque of the electric motor 282 provided corresponding to the turning outer wheel 10 is Tom =
It is determined to be (Td / 2 + Tbrc). Electric motor 28
4, 282 are independently controlled to obtain these torques Tim and Tom. A regenerative braking torque is applied to the turning inner wheel 12, and a driving torque Td /
2 and the regenerative braking torque Tbrc corresponding to the operation amount of the brake pedal 72, the drive torque may be applied or the regenerative braking torque may be applied. The torque of the inner turning wheel 12 is smaller than the torque of the outer turning wheel 10.

When it is determined that the accelerator pedal 44 is depressed, the output torque of the electric motor 284 is Tim = (Tdacc / 2-Td / S33,34).
2 = Tdacc / 2 + Tb / 2), and the electric motor 2
The output torque of 82 is Tom = (Td / 2 + Tdacc / 2)
Is decided. A driving torque is applied to the turning outer wheel 10, and a driving torque Tdacc / 2 and a regenerative braking torque Tb / 2 corresponding to the operation amount of the accelerator pedal 44 are applied to the turning inner wheel 12.
There is a case where the driving torque is applied and a case where the regenerative braking torque is applied depending on the magnitude of and. Accelerator pedal 4
When neither the brake pedal 4 nor the brake pedal 72 is depressed, the output torque of the electric motor 284 is determined as Tim = -Td / 2 = Tb / 2 in S35 and 36, and the output torque of the electric motor 282 is Tom. = Td / 2 is determined. A regenerative braking torque is applied to the turning inner wheel 12, and a driving torque having the same magnitude as the regenerative braking torque applied to the turning inner wheel 12 is applied to the turning outer wheel 10.

As described above, in the present embodiment, the yawing control can be performed only by controlling the electric motors 282 and 284, so that the response delay can be reduced in both control of the drive torque and the regenerative braking torque.
As a result, the change in vehicle speed can be reduced and the response delay of yawing control can be reduced. Further, even when a desired yawing moment is generated, the drive torque can be increased by controlling one electric motor and the regenerative braking torque can be increased by controlling the other electric motor, thus avoiding wasteful energy consumption. can do.

Further, by controlling the electric motor 282 corresponding to the turning outer wheel 10, a driving torque can be applied to the turning outer wheel 10 and a hydraulic braking torque can be applied to the turning inner wheel 12 by the hydraulic braking device 30. The vehicle yawing control device can be applied not only to a hybrid vehicle but also to an electric vehicle. Further, the number of wheels included in one wheel group is not limited to one, and a plurality of wheels may be provided, and the like, which are not exemplified, but various based on the knowledge of those skilled in the art without departing from the scope of the claims. The present invention can be carried out in a modified or improved form.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a part of a vehicle equipped with a vehicle yawing control device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a hydraulic braking device included in the vehicle.

FIG. 3 is a partial cross-sectional view of a linear valve device included in the hydraulic braking device.

FIG. 4 is a diagram showing an example of control in the vehicle yawing control device.

FIG. 5 is a diagram showing torque applied to wheels of the vehicle.

FIG. 6 is a flowchart showing a vehicle yawing control program stored in a ROM of the vehicle yawing control device.

FIG. 7 is a schematic diagram showing a part of a vehicle equipped with a vehicle yawing control device according to another embodiment of the present invention.

FIG. 8 is a flowchart showing a vehicle yawing control program stored in a ROM of the vehicle yawing control device.

[Explanation of symbols]

14,280 Electric drive 28, 282, 284 Electric motor 30 Hydraulic braking device 32,34 wheel cylinders 36 power storage device 40,285,286 Power converter 42 Electric motor control device 46 Vehicle yawing control device 50-56 Linear valve device

Continuation of the front page (56) Reference JP-A-7-298418 (JP, A) JP-A-3-276852 (JP, A) JP-A-5-270385 (JP, A) JP-A-5-176418 (JP , A) JP 5-319144 (JP, A) JP 4-271211 (JP, A) JP 6-247169 (JP, A) JP 6-247168 (JP, A) JP 6-166350 (JP, A) JP 10-295004 (JP, A) JP 5-236606 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60T 8/00 -8/96 B60L 15/20 B60L 7/24

Claims (2)

(57) [Claims] 1. A vehicle yawing control device for controlling yawing of a vehicle having four or more wheels including four wheels located at each of front, rear, left and right, wherein the vehicle is one of the four wheels. A friction member is frictionally engaged with one electric motor connected to the left and right driving wheels of the four wheels through a differential device, and a brake rotating body that rotates together with each of the four wheels, and friction braking torque is applied to the wheels. The vehicle yawing control device increases the drive torque of the electric motor, and at least one of the left and right front and rear wheels and the front and rear wheels on the inside of the turn is provided. The torque difference between the torque applied to the left and right front wheels and the torque applied to the right front wheel is controlled by increasing the pressing force of the friction member against the rotating rotating brake body. A vehicle yawing control device including a friction braking-based left and right wheel torque difference control means. 2. The friction braking-dependent left and right wheel torque difference control means makes the driving torque increase amount of the electric motor and the friction braking torque increase amount corresponding to the pressing force increase substantially the same. vehicle yaw control system of claim 1 including a torque summation invariant torque difference control means for controlling the torque difference as.