JP4239861B2 - Vehicle behavior control device - Google Patents

Description

  The present invention relates to a vehicle behavior control apparatus.

  2. Description of the Related Art Conventionally, a behavior control apparatus that performs behavior control of a vehicle by predicting whether or not the vehicle is in an unstable state is known (for example, see Patent Document 1 below).

According to the behavior control device described in Patent Document 1, the steering angle yaw rate calculated from the steering angle is compared with the yaw rate obtained from the yaw rate sensor, and whether or not the vehicle becomes unstable according to the comparison result. A prediction is made. When the amount of change in the vehicle operation by the driver exceeds a predetermined value when the vehicle is predicted to be unstable, that is, the amount of change in the steering angle exceeds the predetermined value, or the amount of change in the throttle opening When the vehicle exceeds a predetermined value, the braking force and the driving force are adjusted to ensure the stability of the vehicle.
Japanese Patent Laid-Open No. 11-255094 (page 3-5, FIG. 1)

  In the behavior control device, since the change in the road surface condition is not taken into consideration, it is difficult to ensure the stability of the vehicle in a situation where the friction coefficient of the road surface changes abruptly, for example.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a vehicle behavior control device capable of stabilizing the vehicle behavior in a situation where the road surface condition changes rapidly. .

A vehicle behavior control apparatus according to the present invention includes a yaw rate detection means for detecting an actual yaw rate of a vehicle, a yaw rate prediction means for predicting a yaw rate generated after a predetermined time has elapsed based on the actual yaw rate, and a predetermined value based on the speed of the vehicle. A predetermined time setting means for setting time, and a yaw moment adding means for adding a yaw moment opposite to the yaw moment for generating the yaw rate predicted by the yaw rate prediction means to the vehicle after a predetermined time has elapsed. The predetermined time setting means sets the predetermined time based on the vehicle speed and the wheel base .

For example, the vehicle yaw rate may change greatly when entering a road surface with a different road surface friction coefficient during turning of the vehicle. In such a case, according to the vehicle behavior control apparatus of the present invention, the yaw rate generated after the elapse of a predetermined time set based on the vehicle speed is predicted based on the actual yaw rate that is actually generated in the vehicle. The yaw moment that is opposite to the yaw moment that generates the predicted yaw rate is added after a predetermined time has elapsed. By reducing the yaw moment acting on the vehicle, for example, a change in yaw rate when the rear wheel enters the low friction road following the front wheel, that is, a change in vehicle behavior can be suppressed. In the vehicle behavior control apparatus according to the present invention, the predetermined time setting means sets the predetermined time based on the vehicle speed and the wheel base. In this way, since the distance between the front wheel and the rear wheel can be known from the wheel base, the front wheel enters the low friction road and the yaw rate of the vehicle increases, and then the rear wheel follows the front wheel and the low friction road. Therefore, the yaw rate generated when the rear wheel enters the low friction road can be reduced.

The vehicle behavior control apparatus according to the present invention is based on a yaw rate detection means for detecting an actual yaw rate of the vehicle, a yaw rate prediction means for predicting a yaw rate generated after a predetermined time has elapsed based on the actual yaw rate, and a speed of the vehicle. A predetermined time setting means for setting a predetermined time, a yaw moment adding means for adding a yaw moment opposite to the yaw moment for generating the yaw rate predicted by the yaw rate prediction means to the vehicle after a predetermined time, Driving state detecting means for detecting the driving state of the vehicle, and the yaw rate prediction means is configured to execute an actual operation after a predetermined time has elapsed when it is determined that the driving state of the vehicle detected by the driving state detection means is a turning state. It is predicted that a yaw rate in a direction opposite to the yaw rate will occur.

In this way, since the yaw moment is added in the same direction as the detected actual yaw rate, the yaw moment that increases the yaw rate generated in the direction opposite to the actual yaw rate is reduced when the vehicle is turning. Thereby, the vehicle behavior change at the time of vehicle turning can be suppressed.

The vehicle behavior control apparatus according to the present invention is based on a yaw rate detection means for detecting an actual yaw rate of the vehicle, a yaw rate prediction means for predicting a yaw rate generated after a predetermined time has elapsed based on the actual yaw rate, and a speed of the vehicle. A predetermined time setting means for setting a predetermined time, a yaw moment adding means for adding a yaw moment opposite to the yaw moment for generating the yaw rate predicted by the yaw rate prediction means to the vehicle after a predetermined time, A yaw rate predicting means for detecting the running state of the vehicle, and the yaw rate predicting means, after determining that the running state of the vehicle detected by the running state detecting means is a straight running state, It is predicted that a yaw rate in the same direction as the yaw rate is generated.

In this way, since the yaw moment is generated in the direction opposite to the detected actual yaw rate, the yaw moment that increases the yaw rate generated in the same direction as the actual yaw rate is reduced when the vehicle goes straight. Thereby, the change of the yaw rate after the lapse of the predetermined time is suppressed, and the straight traveling state of the vehicle can be maintained.

In this case, it is preferable that the predetermined time setting means sets the predetermined time based on the vehicle speed and the wheel base. In this way, since the distance between the front wheel and the rear wheel can be known from the wheel base, the front wheel enters the low friction road and the yaw rate of the vehicle increases, and then the rear wheel follows the front wheel and the low friction road. Therefore, the yaw rate generated when the rear wheel enters the low friction road can be reduced.

In the vehicle behavior control apparatus according to the present invention, the yaw moment adding means includes a driving means for individually adding a driving force to each of a plurality of wheels provided in the vehicle, and a braking means for individually applying a braking force to each wheel. It is preferable to control at least one of the driving means and the braking means so that a yaw moment that is opposite to the yaw moment that generates the yaw rate predicted by the yaw rate prediction means is added to the vehicle.

In this case, at least one of the driving means and the braking means is controlled, and the yaw moment applied to the vehicle is adjusted so that the yaw moment acting on the vehicle is reduced. Thereby, the change of the yaw rate after the lapse of the predetermined time, that is, the change of the vehicle behavior can be suppressed.

  According to the present invention, it is possible to stabilize the vehicle behavior in a situation where the road surface condition changes suddenly, by adding to the vehicle a yaw moment that reduces the yaw moment that generates the predicted yaw rate. .

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the figure, the same reference numerals are used for the same or corresponding parts.

  First, the configuration of the vehicle behavior control apparatus 1 according to the embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a main configuration of a vehicle V equipped with a vehicle behavior control device 1. FIG. 2 is a diagram illustrating a brake system of the vehicle V. In this specification, the forward direction when the vehicle is moving forward is defined as “front”, and terms such as “front”, “rear”, “left”, and “right” are used.

  Wheels 10FR, 10FL, 10RR, and 10RL are attached to the vehicle V. Here, the wheel 10FR indicates the right front wheel, the wheel 10FL indicates the left front wheel, the wheel 10RR indicates the right rear wheel, and the wheel 10RL indicates the left rear wheel.

  Wheel speed sensors 12FR, 12FL, 12RR, and 12RL that detect the rotational speed of the wheels are attached to the wheels 10FR, 10FL, 10RR, and 10RL. Each wheel speed sensor 12FR to 12RL is connected to an electronic control unit (hereinafter referred to as “motor ECU”) 20 which will be described later.

  As shown in FIG. 2, a brake disk 3 is attached to each wheel 10FR, 10FL, 10RR, 10RL. A brake caliper 6 incorporating a brake pad 4 and a wheel cylinder 5 is attached to each brake disk 3. Each wheel cylinder 5 is connected to a brake actuator 8 via a brake pipe 7.

  The brake actuator 8 has a hydraulic pump, an electromagnetic valve, and the like. At the time of brake braking, the brake oil in the master cylinder 9 is sent to the wheel cylinder 5 through the brake pipe 7 by the hydraulic pump of the brake actuator 8, thereby increasing the hydraulic pressure in the wheel cylinder 5 and causing the wheels 10 FR to 10 RL to move. Brake. Specifically, by increasing the hydraulic pressure in the wheel cylinder 5, the brake pad 4 is pressed against the brake disc 3, and the wheels 10FR to 10RL connected to the brake disc 3 are braked by the frictional force.

  The brake actuator 8 individually adjusts the braking force of each wheel 10FR to 10RL by adjusting the hydraulic pressure in the wheel cylinder 5 by opening and closing the electromagnetic valve. The brake system used in this embodiment is a disc brake system, but may be a drum brake system or the like.

  The brake actuator 8 is connected to an electronic control device (hereinafter referred to as a brake ECU) 18 that controls the braking force acting on the wheels 10FR to 10RL, and a hydraulic pump, an electromagnetic valve, and the like that the brake actuator 8 has are driven by the brake ECU 18. Is done.

  Returning to FIG. 1, the description will be continued. Electric motors 11FR, 11FL, 11RR, 11RL are incorporated inside the wheels 10FR, 10FL, 10RR, 10RL. That is, each of the electric motors 11FR to 11RL is an in-wheel motor, and drives each of the wheels 10FR to 10RL independently. These electric motors 11FR to 11RL function as drive means.

  Electric motors 11FR, 11FL, 11RR, and 11RL are AC synchronous motors and are driven by AC power output from inverter 13. Further, the electric motors 11FR to 11RL can also generate power (regenerative power generation) by using the rotation of the wheels 10FR, 10FL, 10RR, 10RL. At this time, the kinetic energy of the wheels 10FR to 10RL is converted into electric energy, and a braking force based on regenerative power generation is applied to the wheels 10FR to 10RL. The amount of regenerative power generation is adjusted by the motor ECU 20 based on the driver's required braking force, the state of charge of the high voltage battery 14, and the like.

  As described above, the vehicle V applies the regenerative braking force applied to the wheels 10FR to 10RL to the wheels 10FR to 10RL by the regenerative braking of the electric motors 11FR to 11RL and the wheels 10FR to 10RL by pressing the brake pads 4 against the brake disc 3. It is equipped with a friction braking device that applies friction braking force. These regenerative braking devices and friction braking devices function as braking means. A yaw moment adding device that adds a yaw moment to the vehicle V, that is, a yaw moment adding device, includes the electric motors 11FR to 11RL that function as a driving device, a regenerative braking device that functions as a braking device, and a friction braking device. ing.

  Note that the braking force is applied when the regenerative braking force is applied or when the frictional braking force is applied, or when the current supply to the electric motors 11FR to 11RL is stopped. This includes the case where force is applied in the direction of braking the wheels 10FR to 10RL by frictional resistance. Further, when the braking force is applied, the case where the driving force is reduced is also included. In this case, the addition of braking force and the reduction of driving force are considered equivalent.

  The motor ECU 20 and the brake ECU 18 are connected by a communication line 19. When the motor ECU 20 and the brake ECU 18 exchange data with each other via the communication line 19, cooperative control of regenerative braking and friction braking is performed.

  The inverter 13 converts electric power stored in the high voltage battery 14 from direct current to three-phase alternating current based on a control signal from the motor ECU 20 and supplies it to the electric motors 11FR, 11FL, 11RR, 11RL. Further, the inverter 13 converts the electric power regenerated by the electric motors 11FR to 11RL from AC to DC and stores it in the high voltage battery 14.

  The inverter 13 includes current sensors 15FR, 15FL, 15RR, and 15RL that detect phase currents flowing through the three-phase lines 16FR, 16FL, 16RR, and 16RL that connect the electric motors 11FR, 11FL, 11RR, and 11RL to the inverter 13. ing. The actual current value supplied to the electric motors 11FR to 11RL is obtained from the phase current values detected by the current sensors 15FR to 15RL.

  The steering 21 is provided with a steering angle sensor 22 composed of a rotary encoder or the like. The steering angle sensor 22 outputs a signal corresponding to the direction and magnitude of the steering angle input by the driver, and functions as a traveling state detection unit in the present embodiment. The steering angle sensor 22 is connected to the motor ECU 20, and an output signal of the steering angle sensor 22 is input to the motor ECU 20.

  A yaw rate sensor 24 that detects an actual yaw rate that is a yaw rate actually generated in the vehicle V is attached to the vehicle V. The yaw rate sensor 24 is connected to the motor ECU 20, and an output signal from the yaw rate sensor 24 is input to the motor ECU 20.

  In addition to the wheel speed sensors 12FR, 12FL, 12RR, and 12RL, the steering angle sensor 22, and the yaw rate sensor 24, the motor ECU 20 detects an accelerator opening sensor 23 that detects the opening of the accelerator pedal, and detects the acceleration in the lateral direction of the vehicle V. A lateral acceleration sensor 25 and a longitudinal acceleration sensor 26 for detecting longitudinal acceleration of the vehicle V are connected.

  The motor ECU 20 sets the target output of each of the electric motors 11FR to 11RL based on the input signal from each of the sensors, and the switching control signal to the inverter 13 so that the set motor output is output from the electric motors 11FR to 11RL. Is output.

  The motor ECU 20 includes a microprocessor for performing calculations, a ROM for storing a program for causing the microprocessor to execute each process, a RAM for storing various data such as calculation results, and a 12V battery (not shown). Is configured to have a backup RAM or the like that holds the data.

  Then, by the microprocessor or the like, inside the motor ECU 20, a predetermined time setting unit 20 </ b> A that sets a predetermined time to be described later based on the vehicle speed and the wheel base, and a yaw rate prediction that predicts the yaw rate that occurs after the predetermined time has elapsed. Part 20B is constructed. That is, the predetermined time setting unit 20A functions as a predetermined time setting unit, and the yaw rate prediction unit 20B functions as a yaw rate prediction unit.

  Next, the operation of the behavior control apparatus 1 will be described with reference to FIGS. 3 and 4. FIG. 3 is a flowchart showing a processing procedure of behavior control of the vehicle V by the behavior control device 1. FIG. 4 is a flowchart showing a processing procedure of yaw moment calculation processing in behavior control. This process is repeatedly executed every predetermined time. Note that the processing described below is performed by the motor ECU 20 unless otherwise specified. For the yaw rate and yaw moment, the right direction is positive.

  In step S100, the actual yaw rate Yr of the vehicle V detected by the yaw rate sensor 24, the vehicle speed v calculated based on the wheel speeds detected by the wheel speed sensors 12FR to 12RL, and the steering 21 detected by the steering angle sensor 22. The steering angle δ is read.

In step S102, the actual yaw rate Yr read in step S100 it is determined whether the larger than a predetermined value _{Y 0} is performed. Here, the actual yaw rate Yr is the process to step S104 shifts to larger than the predetermined value _{Y 0.} On the other hand, if the actual yaw rate Yr is less than a predetermined value Y ₀ is temporarily exits this process.

  In step S104, the target yaw moment M to be added to the vehicle V is calculated. Here, the target yaw moment M calculation process performed in step S104 will be described with reference to FIG.

In step S200, the steering angle [delta] read in step S100 it is determined whether the larger than the predetermined value [delta] ₀ is performed. If the steering angle δ is greater than the predetermined value δ ₀ , it is determined that the vehicle V is in a turning state, and the process proceeds to step S202. On the other hand, if the steering angle δ is equal to or smaller than the predetermined value δ ₀ , it is determined that the vehicle V is in a straight traveling state, and the process proceeds to step S204.

  In step S202, the predicted yaw rate Yf at the time of turning is obtained by the following equation.

Yf = −Yr (1)
Here, the predicted yaw rate Yf, after being detected predetermined value Y ₀ is greater than the actual yaw rate Yr, a yaw rate that is expected to occur after a predetermined later time. As shown in Equation (1), it is predicted that a yaw rate in the direction opposite to the detected actual yaw rate Yr will occur when the vehicle turns. Thereafter, the process proceeds to step S206.

  In step S204, the predicted yaw rate Yf when traveling straight is obtained by the following equation.

Yf = Yr (2)
As shown in Equation (2), when the vehicle is traveling straight, it is predicted that a yaw rate in the same direction as the detected actual yaw rate Yr will occur.

  In step S206, based on the predicted yaw rate Yf obtained in step S202 or S204, the target yaw moment M to be added to the vehicle V is calculated by the following equation. The target yaw moment M is determined so as to reduce the yaw moment Mf that generates the predicted yaw rate Yf.

M = −I × (dYf / dt) (3)
Here, I is the yaw moment of inertia of the vehicle V.

  After the target yaw moment M is calculated in step S206, the process proceeds to step S106 in FIG.

In step S106, the predetermined time L / v is calculated by dividing the wheel base L of the vehicle V by the vehicle speed v. Predetermined time L / v, after a predetermined value Y ₀ is greater than the actual yaw rate Yr is detected, a time until the predicted yaw rate Yf occurs. Specifically, this is the time from when the front wheels 10FR and 10FL pass through a low μ road surface such as a joint between road surfaces until the rear wheels 10RR and 10RL pass through the low μ road surface.

  In the subsequent step S108, the driving force or braking force (hereinafter referred to as “driving force / braking force”) F applied to each of the front wheels 10FR and 10FL of the vehicle V is obtained based on the target yaw moment M calculated in step S104. It is done. The driving force / braking force F is obtained by an arithmetic expression, a preset map, or the like.

  In the case of an arithmetic expression, the driving force F + and the braking force F− are calculated by the following expressions (4) and (5).

F + = M / T (4)
F − = − M / T (5)
Here, T is the distance between the left and right wheels.

  Next, how to determine the driving force / braking force F using the map will be described. The ROM of the motor ECU 20 stores a map (driving force / braking force map) that defines the relationship between the target yaw moment M and the driving force / braking force F for each of the right front wheel 10FR and the left front wheel 10FL. By searching the driving force / braking force map based on the yaw moment M, the driving force / braking force F applied to the front wheels 10FR, 10FL is obtained.

  As shown in FIG. 5A, the driving force / braking force map of the right front wheel 10FR shows that when the target yaw moment M is zero, the driving force / braking force F is zero and the target yaw moment M is positive. The braking force F− is increased as the direction increases, and the driving force F + is increased as the target yaw moment M increases in the negative direction.

  On the other hand, as shown in FIG. 5B, the driving force / braking force map of the left front wheel 10FL shows that when the target yaw moment M is zero, the driving force / braking force F is zero and the target yaw moment M is The driving force F + is increased as it increases in the positive direction, and the braking force F− is increased as the target yaw moment M increases in the negative direction.

  Thus, by setting the driving force / braking force F applied to the right front wheel 10FR and the left front wheel 10FL, the right front wheel 10FR and the left front wheel 10FL have a magnitude relative to a predetermined target yaw moment M, respectively. Equal and opposite forces are applied. Further, as the target yaw moment M increases in the positive direction, the braking force applied to the right front wheel 10FR increases F, and the driving force F + applied to the left front wheel 10FL increases. The yaw moment increases. On the other hand, as the target yaw moment M increases in the negative direction, the driving force F + applied to the right front wheel 10FR increases and the braking force F- applied to the left front wheel 10FL increases. The yaw moment increases.

  In step S110, after the predetermined time set in step S106 has elapsed, the driving force / braking force F is applied to the front wheels 10FR, 10FL, and the target yaw moment M is added to the vehicle V. Specifically, first, based on the driving force / braking force F, the command value of the current added to each of the electric motors 11FR and 11FL is calculated.

  The current command value is obtained by a preset map, an arithmetic expression, or the like. Here, how to obtain the current command value of the right front wheel 10FR will be described by taking a case of using a map as an example. Note that the method of obtaining the current command value for the left front wheel 10FL is the same as that for the right front wheel 10FR, and thus the description thereof is omitted here.

  The ROM of the motor ECU 20 stores a map (current command value map) that defines the relationship between the driving force / braking force F and the current command value, and this current command value map is based on the driving force / braking force F. Is retrieved to obtain the current command value to be added to the front wheels 10FR, 10FL.

  As shown in FIG. 6, the current command value map of the right front wheel 10FR is zero when the driving force / braking force F is zero, and the current command value increases as the driving force F + increases. The current command value is set to decrease as the braking force F- increases.

  Next, a current command value for generating the target yaw moment M is added to the target current value calculated based on the running state of the vehicle V and supplied to each of the electric motors 11FR and 11FL. Is increased / decreased to adjust the driving force / braking force F applied to the front wheels 10FR, 10FL. Thus, the target yaw moment M is added to the vehicle V by adjusting the driving force / braking force F of the right front wheel 10FR and the left front wheel 10FL. When the result obtained by subtracting the current command value from the target current value is a positive value, the driving force is reduced by adding the target current value, that is, the braking force is added. When the value obtained by subtracting the current command value from the target current value becomes negative, braking force is applied to the front wheels 10FR and 10FL by regenerative braking and friction braking.

  Next, the actual yaw rate Yr, the target yaw moment M, and the front wheels 10FR, 10FL of the vehicle V when the vehicle V passes during a turn, for example, where a road surface friction coefficient changes abruptly, such as a road surface joint. The state of the driving force / braking force F applied to the will be described with reference to FIG. FIG. 7 is a timing chart showing changes in (a) yaw rate (b) target yaw moment (c) front wheel additional torque.

  When the front wheels 10FR and 10FL pass through a portion where the road surface friction coefficient changes suddenly when the vehicle turns, for example, when an actual yaw rate Yr indicated by a solid line in FIG. ), A predicted yaw rate Yf indicated by a dotted line is obtained. As described above, the predicted yaw rate Yf is predicted to occur in the opposite direction to the actual yaw rate Yr when the vehicle is turning.

  Subsequently, the yaw moment Mf for generating the predicted yaw rate Yf indicated by the dotted line in FIG. 7B is calculated. Then, a target yaw moment M for reducing the yaw moment Mf indicated by a solid line in FIG. 7B is obtained. The target yaw moment M is a yaw moment having the same magnitude and the opposite direction as the yaw moment Mf.

  Based on the target yaw moment M, the driving force / braking force F applied to the front wheels 10FR, 10FL is obtained. After a predetermined time elapses, the current value supplied to the electric motors 11FR and 11FL is adjusted, and as shown in FIG. 7C, the braking force F− is applied to the right front wheel 10FR and the left front wheel 10FL is driven. A force F + is added. As a result, a yaw moment is generated in the vehicle V in the right direction, that is, in the direction opposite to the yaw moment Mf.

  In this way, after a predetermined time has elapsed, that is, when the rear wheels 10RR and 10RL pass through a portion where the road surface friction coefficient changes rapidly, the yaw moment Mf that generates the predicted yaw rate Yf is reduced, and the behavior change of the vehicle V is changed. Is suppressed.

  Next, the actual yaw rate Yr, the target yaw moment M, and the front wheels 10FR, 10FL of the vehicle V when the vehicle V passes through a portion where the road surface friction coefficient changes abruptly, for example, at the joint of the road surface, while traveling straight ahead. The state of the driving force / braking force F applied to the will be described with reference to FIG. FIG. 8 is a timing chart showing changes in (a) yaw rate (b) target yaw moment (c) front wheel additional torque.

  When the front wheel 10FR, 10FL passes through a portion where the road surface friction coefficient changes suddenly when the vehicle goes straight, for example, when an actual yaw rate Yr indicated by a solid line in FIG. ), A predicted yaw rate Yf indicated by a dotted line is obtained. As described above, the predicted yaw rate Yf is predicted to occur in the same direction as the actual yaw rate Yr when the vehicle is traveling straight ahead.

  Subsequently, the yaw moment Mf for generating the predicted yaw rate Yf indicated by the dotted line in FIG. 8B is calculated. Then, a target yaw moment M for reducing the yaw moment Mf indicated by a solid line in FIG. 8B is obtained. The target yaw moment M is a yaw moment having the same magnitude and the opposite direction as the yaw moment Mf.

  Based on the target yaw moment M, the driving force / braking force F applied to the front wheels 10FR, 10FL is obtained. After a predetermined time has elapsed, the current value supplied to the electric motors 11FR and 11FL is adjusted, and as shown in FIG. 8C, the driving force F + is added to the right front wheel 10FR and the braking force is applied to the left front wheel 10FL. F- is added. As a result, a yaw moment is generated in the vehicle V in the left direction, that is, in the direction opposite to the yaw moment Mf.

  In this manner, after a predetermined time has elapsed, that is, when the rear wheels 10RR and 10RL pass through a place where the road surface friction coefficient changes rapidly, the yaw moment Mf that generates the predicted yaw rate Yf is reduced, and the behavior change of the vehicle V is changed. Is suppressed.

  According to the present embodiment, when the vehicle V passes a low μ road surface such as a road joint, for example, a predicted yaw rate Yf predicted to occur when the rear wheels 10RR and 10RL pass the low μ road surface, And after the front wheels 10FR, 10FL pass the low μ road surface, a predetermined time L / v until the rear wheels 10RR, 10RL pass is obtained. When the rear wheels 10RR and 10RL pass through the low μ road surface, that is, after a predetermined time L / v has elapsed, the driving force F + or the braking force F− is applied to the front wheels 10FR and 10FL, respectively. The yaw moment Mf that generates the predicted yaw rate Yf is reduced by the yaw moment generated by the addition of the driving force F + or the braking force F−. Therefore, the change in vehicle behavior when the rear wheels 10RR and 10RL pass through the low μ road surface can be suppressed, and the vehicle stability can be improved.

As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said embodiment, A various deformation | transformation is possible. In the present embodiment, when the actual yaw rate Yr is greater than a predetermined value Y _0, but adds a yaw moment to the yaw moment Mf and opposite to generate a predicted yaw Yf, additional yaw moment on the basis of other conditions May be. For example, when the change in the actual yaw rate Yr becomes larger than a predetermined value, the yaw moment may be added in the direction opposite to the yaw moment Mf. Further, the yaw moment may always be added in the direction opposite to the yaw moment Mf.

  In this embodiment, a yaw moment having the same magnitude as the yaw moment Mf that generates the predicted yaw rate Yf is added in the opposite direction to the yaw moment Mf. However, any yaw moment that can reduce the yaw moment Mf is used. For example, any magnitude of yaw moment may be added. For example, a yaw moment smaller than the yaw moment Mf may be added in the direction opposite to the yaw moment Mf.

  Furthermore, in the present embodiment, the yaw moment applied to the vehicle V is controlled using the electric motors 11FR to 11RL that function as driving means, and the regenerative braking device and friction braking device that function as braking means. Any means may be used as long as the yaw moment can be controlled by the driving force or the braking force. For example, the yaw moment may be controlled by either the driving means or the braking means.

  In the present embodiment, the in-wheel motors 11FR to 11RL for independently driving the wheels 10FR to 10RL are used. However, any in-wheel motor can be used as long as the wheels 10FR to 10RL can be independently driven. It does not have to be. For example, an electric motor may be attached to the vehicle body side, and the electric motor and wheels may be coupled by a drive shaft or the like.

1 is a diagram illustrating a main configuration of a vehicle equipped with a vehicle behavior control device according to an embodiment. 1 is a diagram showing a vehicle brake system equipped with a vehicle behavior control device according to an embodiment. It is a flowchart which shows the process sequence of the behavior control by the vehicle behavior control apparatus which concerns on embodiment. It is a flowchart which shows the process sequence of the yaw moment calculation process in behavior control. It is a figure which shows the relationship between the target yaw moment of (a) right front wheel and (b) left front wheel, and the driving force / braking force added. It is a figure which shows the relationship between the drive force / braking force added, and electric current command value. It is a timing chart which shows an example of change of (a) yaw rate (b) target yaw moment (c) front wheel additional torque at the time of vehicle turning. It is a timing chart which shows an example of a change of (a) yaw rate (b) target yaw moment (c) front wheel additional torque at the time of straight ahead of vehicles.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Behavior control apparatus, 3 ... Brake disc, 4 ... Brake pad, 5 ... Wheel cylinder, 6 ... Brake caliper, 7 ... Brake piping, 8 ... Brake actuator, 9 ... Master cylinder, 10FR, 10FL, 10RR, 10RL ... Wheel , 11FR, 11FL, 11RR, 11RL ... electric motor, 12FR, 12FL, 12RR, 12RL ... wheel speed sensor, 13 ... inverter, 14 ... high voltage battery, 15FR, 15FL, 15RR, 15RL ... current sensor, 18 ... brake ECU, DESCRIPTION OF SYMBOLS 20 ... Motor ECU, 20A ... Predetermined time setting part, 20B ... Yaw rate estimation part, 21 ... Steering, 22 ... Steering angle sensor, 23 ... Accelerator opening sensor, 24 ... Yaw rate sensor, 25 ... Lateral acceleration sensor, 26 ... Longitudinal acceleration Sensor, V ... vehicle.

Claims (5)

Yaw rate detection means for detecting the actual yaw rate of the vehicle;
A yaw rate prediction means for predicting a yaw rate generated after a predetermined time has elapsed based on the actual yaw rate;
Predetermined time setting means for setting the predetermined time based on the speed of the vehicle;
A yaw moment adding means for adding a yaw moment opposite to the yaw moment for generating the yaw rate predicted by the yaw rate prediction means to the vehicle after the predetermined time has elapsed ,
The vehicle behavior control device characterized in that the predetermined time setting means sets the predetermined time based on a speed and a wheel base of the vehicle. Yaw rate detection means for detecting the actual yaw rate of the vehicle;
A yaw rate prediction means for predicting a yaw rate generated after a predetermined time has elapsed based on the actual yaw rate;
Predetermined time setting means for setting the predetermined time based on the speed of the vehicle;
A yaw moment adding means for adding a yaw moment opposite to the yaw moment for generating the yaw rate predicted by the yaw rate prediction means to the vehicle after the predetermined time has elapsed;
Traveling state detection means for detecting the traveling state of the vehicle ,
The yaw rate prediction means predicts that a yaw rate in a direction opposite to the actual yaw rate will occur after the predetermined time has elapsed when it is determined that the running state of the vehicle detected by the running state detection means is a turning state. A vehicle behavior control device. Yaw rate detection means for detecting the actual yaw rate of the vehicle;
A yaw rate prediction means for predicting a yaw rate generated after a predetermined time has elapsed based on the actual yaw rate;
Predetermined time setting means for setting the predetermined time based on the speed of the vehicle;
A yaw moment adding means for adding a yaw moment opposite to the yaw moment for generating the yaw rate predicted by the yaw rate prediction means to the vehicle after the predetermined time has elapsed;
Traveling state detection means for detecting the traveling state of the vehicle ,
The yaw rate prediction means predicts that a yaw rate in the same direction as the actual yaw rate will occur after the predetermined time has elapsed when it is determined that the running state of the vehicle detected by the running state detection means is a straight running state. A vehicle behavior control device. The vehicle behavior control device according to claim 2 or 3 , wherein the predetermined time setting means sets the predetermined time based on a speed and a wheel base of the vehicle. The yaw moment adding means is
Driving means for individually adding driving force to each of the plurality of wheels provided in the vehicle;
Braking means for individually applying a braking force to each of the wheels,
The at least one of the driving unit and the braking unit is controlled so that a yaw moment that is opposite to a yaw moment that generates a yaw rate predicted by the yaw rate prediction unit is added to the vehicle. Item 5. The vehicle behavior control device according to any one of Items 1 to 4 .

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