JP2001191820A - Behavior control device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a behavior control device for automobile capable of finely controlling the behavior of a vehicle in an area, in which the yaw rate behavior is small so that the sufficient control by an engine and a brake is impossible, and capable of improving the traveling performance in that area, improving the acceleration performance when accelerating again by providing a continuously variable transmission for continuously changing the rotary power of the engine, and controlling the yaw rate of the vehicle with a control means for controlling the yaw rate behavior of the vehicle while using the continuously variable transmission. SOLUTION: This behavior control device for automobile is provided with a control means for estimating the traveling condition of the vehicle and for controlling the yaw rate behavior of the vehicle on the basis of the result of the estimation. This control device is provided with a continuously variable transmission for continuously changing the rotary power of an engine, and the control means performs the behavior control S7 of the vehicle with the continuously variable transmission.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle behavior control device for estimating a state of a vehicle at the time of turning and controlling a yaw rate behavior of the vehicle based on the estimation result to eliminate understeer and oversteer. .

[0002]

2. Description of the Related Art Conventionally, as a vehicle behavior control device of the above-mentioned example, there is a device having the following configuration, for example. That is,
Behavior control means for controlling the braking force at the time of turning of the vehicle (braking force) or the output of a prime mover (engine) to stabilize the turning behavior of the vehicle, and the gear position of the automatic transmission based on the running state of the vehicle. Gear shift control means for automatically switching, and gear position fixing means for inhibiting a shift by the shift control means and fixing a gear position of the automatic transmission during turning behavior control of the vehicle by the behavior control means. This is a vehicle behavior control device (see Japanese Patent Application Laid-Open No. 10-236186).

According to this conventional apparatus, when it is determined that the vehicle state has an oversteer tendency indicating an excessive turning angle (spin) with respect to the steering angle or an understeering tendency indicating an excessive turning angle with respect to the operation angle. In this case, the engine output is reduced, and a braking force is applied to the front wheels or the rear wheels or a part thereof to generate an oversteer suppression moment or an understeer suppression moment, thereby stabilizing the turning behavior of the vehicle.

In addition, during the turning behavior control of the vehicle by the behavior control means, the gear position of the automatic transmission is fixed by the fixing means. The behavior can be prevented from becoming unstable.

However, this conventional apparatus has the following problems. That is, in the conventional device described above, only the behavior control by the engine and the behavior control by the braking force (brake) are used to stabilize the turning behavior of the vehicle. In a fine control area in a small area of
In particular, when the behavior control by the engine is used, the drop of the engine rotation is large, and when the behavior control by the brake is used, the deceleration amount becomes too large, causing vibration, running performance in the region, and re-acceleration. There is a problem that the acceleration performance at the time is deteriorated.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a continuously variable transmission for continuously changing the rotational power of an engine, and control means for controlling the vehicle yaw rate behavior controls the vehicle behavior by the continuously variable transmission. By doing so, it is possible to perform fine behavior control in a small area of the yaw rate behavior where sufficient control by the engine or the brake is impossible, and to improve the traveling performance in the area and the acceleration performance at the time of re-acceleration. For the purpose of providing.

[0007]

According to the present invention, there is provided an automobile behavior control apparatus comprising control means for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result. A continuously variable transmission for continuously changing the rotational power of the engine is provided, and the control means controls the behavior of the vehicle by the continuously variable transmission.

According to the above configuration, the control means changes the speed ratio of the continuously variable transmission and controls the vehicle speed to execute the behavior control of the vehicle, thereby stabilizing the posture when the vehicle turns. , Fine behavior control can be performed in a region where the yaw rate behavior is small where sufficient control cannot be performed by the engine or the brake, and the traveling performance can be ensured in the region.
Since a large change in driving force can be obtained with a small change in the gear ratio, the acceleration performance at the time of re-acceleration can be improved.

According to a second aspect of the present invention, the behavior control includes a behavior control using a brake and a behavior control using a continuously variable transmission. When the behavior control is interposed, the behavior control using the continuously variable transmission takes precedence over the behavior control using the brake. Is performed.

With the above configuration, the control means preferentially executes the behavior control by the continuously variable transmission when the behavior control is interposed, so that an excessive decrease in driving force due to the brake can be prevented, and the behavior control by the continuously variable transmission can be prevented. Thus, the posture can be stabilized when the vehicle turns.

According to a third aspect of the present invention, the behavior control includes behavior control by an engine and behavior control by a continuously variable transmission, and the behavior control by the continuously variable transmission takes precedence over the behavior control by the engine when the behavior control is interposed. Is performed. According to the above configuration, the control means preferentially executes the behavior control by the continuously variable transmission at the time of the intervention of the behavior control, so that an excessive drop of the engine rotation can be prevented, so that the re-acceleration performance can be enhanced, In addition, the attitude control during turning of the vehicle can be stabilized by the behavior control by the continuously variable transmission.

According to a fourth aspect of the present invention, the behavior control includes behavior control by an engine, behavior control by a brake, and behavior control by a continuously variable transmission. Priority is set in the order of the behavior control by the brake and the behavior control by the brake.

According to the above configuration, since suitable devices intervene in order according to the magnitude of the behavior, the change in the behavior can be suppressed smoothly, and the posture during the turning of the vehicle can be stabilized.

According to a fifth aspect of the present invention, the behavior control by the continuously variable transmission and the behavior control by the brake are provided, and the threshold of the behavior control by the continuously variable transmission is set to be smaller than the threshold of the behavior control by the brake. It is set to small.

According to the above configuration, when the control means becomes equal to or more than the threshold value for starting the behavior control by the continuously variable transmission, the control means starts the behavior control by the continuously variable transmission preferentially. Since a decrease in torque can be prevented, the attitude control during turning of the vehicle can be achieved by behavior control using the continuously variable transmission without deteriorating the vehicle running performance.

According to a sixth aspect of the present invention, there is provided a behavior control using a continuously variable transmission and a behavior control using an engine. Is set to small.

According to the above configuration, when the control means exceeds the threshold value for starting the behavior control by the continuously variable transmission, the control means starts the behavior control by the continuously variable transmission preferentially. The control of the behavior of the continuously variable transmission can stabilize the posture during turning of the vehicle while preventing the vehicle from getting stuck.

The invention according to claim 7 is provided with a behavior control by a continuously variable transmission, a behavior control by an engine, and a behavior control by a brake, and a threshold value of a behavior control start by the continuously variable transmission <a behavior control by an engine. The threshold value for the start is set to be smaller than the threshold value for the start of the behavior control by the brake.

With the above configuration, when the control means has exceeded a threshold value for starting the behavior control by the continuously variable transmission (the minimum threshold value among the three threshold values), the control means uses the continuously variable transmission. Since the behavior control is started with the highest priority, a suitable device intervenes in order according to the magnitude of the behavior, so that the behavior change can be suppressed smoothly.

According to an eighth aspect of the present invention, the control means is in a first predetermined state (see understeer state, accelerator non-depressed state).
, The drive torque is reduced by the continuously variable transmission,
This controls the behavior of the vehicle.

With the above arrangement, when the first predetermined state is detected, the control means controls the speed ratio of the continuously variable transmission to reduce the driving torque, reduce the vehicle speed, and thereby control the behavior. Therefore, the posture can be stabilized when the vehicle turns.

According to a ninth aspect of the present invention, the first predetermined state is set to an understeer state of the vehicle. According to the above configuration, when understeer as the first predetermined state is detected, the control means controls the speed ratio of the continuously variable transmission to reduce the driving torque, reduce the vehicle speed, and thereby perform the behavior control. Therefore, understeer is eliminated, and the posture of the vehicle at the time of turning can be stabilized.

According to a tenth aspect of the present invention, the first predetermined state is set to an accelerator non-depressed state. With the above configuration, when the accelerator non-depressed state as the first predetermined state is detected, the control means controls the speed ratio of the continuously variable transmission to reduce the vehicle speed, thereby performing behavior control. In other words, when the accelerator is not in the non-stepped-on state (that is, when the accelerator is stepped on), it is difficult to expect the behavior control by the continuously variable transmission.

According to an eleventh aspect of the present invention, the control means includes a second control means.
A predetermined state (refer to an accelerator ON state, a steady running state, and a deceleration running state) is detected, and the continuously variable transmission is controlled to the upshift side.

With the above configuration, when the second predetermined state is detected, the control means controls the continuously variable transmission to shift up (to decrease the gear ratio), to reduce the vehicle speed,
As a result, behavior control can be performed to stabilize the posture when the vehicle turns.

That is, the vehicle driving force is obtained by multiplying the engine driving force by the gear ratio, and the vehicle driving force is reduced by decreasing the gear ratio when the second predetermined state is detected.
A stall condition results, which can reduce the vehicle speed.

According to a twelfth aspect of the present invention, the second predetermined state is set to an accelerator ON state. According to the above configuration, when the accelerator ON state as the second predetermined state is detected, the control unit controls the continuously variable transmission to the upshift side (a direction in which the gear ratio decreases), reduces the drive torque,
The vehicle speed is reduced, and the behavior control is thereby performed, whereby the posture during the turning of the vehicle can be stabilized.

According to a thirteenth aspect of the present invention, the second predetermined state is set to an accelerator ON state and a predetermined steady running state. According to the above configuration, when the accelerator ON state as the second predetermined state and the steady running state of the vehicle are detected, the control means controls the continuously variable transmission to shift up (to reduce the gear ratio) and to increase the driving torque. To reduce the vehicle speed and thereby control the behavior,
It is possible to stabilize the posture when the vehicle turns.

According to a fourteenth aspect of the present invention, the second predetermined state is set to an accelerator ON state and a decelerating running state of the vehicle. According to the above configuration, when the accelerator ON state as the second predetermined state and the decelerating traveling state of the vehicle are detected, the control means controls the continuously variable transmission to the upshift side (the direction in which the gear ratio decreases), and the driving torque To reduce the vehicle speed and thereby control the behavior,
It is possible to stabilize the posture when the vehicle turns.

According to a fifteenth aspect of the present invention, the control means detects an accelerator OFF state and controls the continuously variable transmission to a downshift side. With the above structure, when the accelerator OFF state is detected, the control means controls the continuously variable transmission to the downshift side (in a direction in which the gear ratio increases) to increase the engine braking effect and reduce the vehicle speed, thereby reducing the behavior. By performing the control, the posture can be stabilized when the vehicle turns.

According to a sixteenth aspect of the present invention, the control means is in a predetermined prohibited state (for example, when the engine speed is higher than a predetermined high speed,
When a predetermined low rotation or less is detected, the behavior control by the continuously variable transmission is stopped. According to the above configuration, when the predetermined prohibition state is detected, the control unit stops the behavior control by the continuously variable transmission, so that it is possible to prevent the behavior control from being adversely affected.

According to a seventeenth aspect of the present invention, the predetermined prohibited state is such that the engine speed is set to a predetermined high rotation or higher and a predetermined low rotation or lower. According to the above configuration, when it is detected that the engine speed is equal to or higher than the predetermined high speed and equal to or lower than the predetermined low speed as the predetermined prohibition state, the control means stops the behavior control by the continuously variable transmission. It is possible to prevent a change in behavior due to a sudden acceleration at the time of a driver's re-acceleration operation accompanying the climb and to prevent an engine stop.

The invention of claim 18 is the one in which the predetermined prohibition state is such that the change amount of the engine speed difference is set to a predetermined value or more after the shift control by the continuously variable transmission. According to the above configuration, when it is detected that the change amount of the engine speed difference in the predetermined prohibition state is equal to or more than the predetermined value, the control means stops the behavior control by the continuously variable transmission, so that the engine speed is excessively increased. It is possible to prevent a change in behavior due to a sudden acceleration of the driver's maximum accelerator operation accompanying the climb and an engine stop.

According to a nineteenth aspect of the present invention, in the predetermined prohibited state, the rate of change of the engine speed is set to a predetermined value or more. According to the above configuration, when it is detected that the rate of change of the engine speed in the predetermined prohibition state is equal to or higher than a predetermined value, the control means stops the behavior control by the continuously variable transmission, so that the engine speed is excessively increased. Accordingly, it is possible to prevent a change in behavior due to a sudden acceleration of the driver's most accelerator operation and a stop of the engine.

According to a twentieth aspect of the present invention, the predetermined prohibition state is such that the change amount of the gear ratio is set to a value equal to or more than a predetermined value. According to the above configuration, when it is detected that the change amount of the gear ratio in the continuously variable transmission in the predetermined prohibited state is equal to or larger than the predetermined value, the control unit stops the behavior control by the continuously variable transmission. It is possible to prevent a change in behavior due to a sudden acceleration of the driver's maximum accelerator operation due to an excessive blow-up and an engine stop.

According to a twenty-first aspect of the present invention, the predetermined prohibited state is set to a state in which the throttle opening is increased. With the above configuration, when the increase in the throttle opening as the predetermined prohibition state is detected, the control unit stops the behavior control by the continuously variable transmission. That is, since it is difficult to expect the behavior control by the continuously variable transmission when the throttle opening is increased, the effect is obtained by other control.

According to a twenty-second aspect of the present invention, the predetermined prohibition state is set to a start state of behavior control by the engine. With the above configuration, when detecting that the behavior control by the engine in the predetermined prohibited state has been started, the control unit stops the behavior control by the continuously variable transmission. Therefore, it is possible to prevent the behavior control from becoming unstable due to a change in the gear ratio of the continuously variable transmission during the behavior control by the engine.

According to a twenty-third aspect of the present invention, the predetermined prohibition state is set to a start state of behavior control by a brake. With the above configuration, when detecting that the behavior control by the brake in the predetermined prohibition state has been started, the control unit stops the behavior control by the continuously variable transmission. Therefore, it is possible to prevent the behavior control from becoming unstable due to a change in the gear ratio of the continuously variable transmission during the behavior control by the brake.

According to a twenty-fourth aspect of the present invention, there is provided a vehicle behavior control device comprising control means for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result. A continuously variable transmission that continuously changes gears is provided, and when the convergence of the behavior control is determined, the control means controls the continuously variable transmission to the downshift side.

According to the above configuration, when the convergence of the behavior control is determined, the control means controls the continuously variable transmission to the downshift side (in a direction in which the gear ratio increases). Can be secured.

According to a twenty-fifth aspect of the present invention, there is provided an automobile behavior control apparatus comprising control means for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result. A continuously variable transmission that continuously changes gears is provided, and when it is determined that the behavior control has converged, the control means changes the continuously variable transmission in a direction in which upshifting is suppressed.

According to the above configuration, when the convergence of the behavior control is determined, the control means sets the continuously variable transmission in the direction in which the upshift is suppressed (the engine speed is adjusted to the driver's acceleration request based on the driver's acceleration request). This is a mode in which the gear ratio is changed so as to approach the corresponding target rotation speed, and control is performed in a mode in which acceleration is emphasized), so that acceleration performance after the end of behavior control can be ensured.

According to a twenty-sixth aspect of the present invention, there is provided a vehicle behavior control device including control means for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result. A continuously variable transmission that continuously changes the speed is provided, and when the intervention of the behavior control by the engine is started, the control means controls the continuously variable transmission to the upshift side or reduces the operating oil pressure supplied to the continuously variable transmission. The pressure increase is controlled.

With the above configuration, when the intervention of the behavior control by the engine is started, the above-mentioned control means controls the continuously variable transmission to the upshift side to reduce the speed ratio or to control the continuously variable transmission. Since the supplied operating oil pressure is controlled to increase, slippage of the continuously variable transmission can be prevented, and protection of the continuously variable transmission can be achieved.

According to a twenty-seventh aspect of the present invention, there is provided a vehicle behavior control device including control means for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result. When a continuously variable transmission that continuously changes the speed is provided, and the intervention of the behavior control by the brake is started, the control means controls the continuously variable transmission to the upshift side or reduces the operating hydraulic pressure supplied to the continuously variable transmission. The pressure increase is controlled.

With the above configuration, when the intervention of the behavior control by the brake is started, the above-described control means controls the continuously variable transmission to the upshift side to reduce the speed ratio or to control the continuously variable transmission. Since the supplied operating oil pressure is controlled to increase, slippage of the continuously variable transmission can be prevented, and protection of the continuously variable transmission can be achieved.

According to a twenty-eighth aspect of the present invention, there is provided a vehicle behavior control device including a control means for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result. A continuously variable transmission that continuously changes the speed is provided, and when the behavior is controlled by the brake, the control means controls the speed ratio of the continuously variable transmission to the upshift side or increases the hydraulic pressure supplied to the continuously variable transmission. After that, the behavior control by the brake is started.

With the above configuration, at the start of the intervention of the behavior control by the brake, the control means first controls the continuously variable transmission to the upshift side to reduce its speed ratio and is transmitted from the wheels to the continuously variable transmission. After reducing the sensitivity to load or increasing the operating oil pressure supplied to the continuously variable transmission to prevent slippage of the continuously variable transmission, the behavior control by the brake is started. Even better protection can be achieved.

According to a twenty-ninth aspect of the present invention, there is provided an automobile behavior control apparatus comprising control means for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result. A continuously variable transmission that continuously changes gears is provided, and when an oversteer state of the vehicle is detected, the control means controls the continuously variable transmission to the upshift side.

With the above configuration, when an oversteer state of the vehicle is detected, the control means controls the continuously variable transmission to shift up to reduce the speed ratio. For this reason, when the oversteer state is eliminated by the behavior control using the brake, a braking force is applied to the outer front wheel. However, by controlling the continuously variable transmission to the upshift side to reduce the sensitivity, the wheel is controlled. Thus, the reaction torque due to the braking of the vehicle can be reduced, the transmission of vibration to the vehicle body can be reduced, and the continuously variable transmission can be protected.

[0051]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The drawings show a behavior control device of an automobile. First, an overall configuration of the behavior control device will be described with reference to FIG.

First, each device on the input side will be described. 1 is a wheel detection sensor for detecting the wheel speed of each wheel.
Reference numeral 2 denotes a steering angle sensor that detects a steering angle of a steering wheel (steering wheel), 3 denotes a yaw rate sensor that detects a yaw rate generated in the vehicle, and 4 denotes a lateral acceleration sensor (lateral G sensor) that detects a lateral acceleration of the vehicle. Reference numeral 5 denotes a throttle opening sensor for detecting a throttle opening, reference numeral 6 denotes a stop lamp switch for canceling control of an antilock brake system (hereinafter simply referred to as ABS) described later, and reference numeral 7 denotes an engine for detecting an engine speed. This is a rotation speed sensor, which is detected to perform feedback control of the engine output.

Reference numeral 8 denotes a shift position detection sensor (AT) for detecting a shift position in order to detect an operation state of the engine (power train). The shift position detection sensor 8 controls the behavior in the case of reverse. It is also used as a cancel switch for canceling. 9 is the first
An MC hydraulic pressure sensor for detecting the hydraulic pressure of a master cylinder MC as a hydraulic pressure generation source. The hydraulic pressure sensor is adapted to change the brake hydraulic pressure according to the detection result of the MC hydraulic pressure sensor 9 in accordance with the driver's brake pedal depressing force. Is corrected. On the other hand, 10 is a reservoir level switch for detecting the presence of brake fluid in the reservoir, and 11 is an accelerator opening sensor for detecting the accelerator opening.

Next, a description will be given of each device on the output side. Numeral 12 indicates an alarm which indicates that the ABS 13 is operating.
A BS lamp 14 is a pressurizing motor as a pressurizing and depressurizing means provided in a pressurizing pump as a second hydraulic pressure source, and 15 and 1.
Reference numeral 6 denotes a front solenoid valve and a rear solenoid valve as pressurizing and depressurizing means for supplying and discharging brake fluid (oil pressure) to and from a brake device such as a disc brake provided for a front wheel and a rear wheel. A TSW solenoid valve as a pressurizing / depressurizing means for shutting off / opening each wheel to / from a brake device side;
Reference numeral 8 denotes an ASW solenoid valve as a pressurizing / depressurizing means for shutting off / opening between the master cylinder and the pressurizing pump, 19 an engine controller for controlling the engine output, and 20 a vehicle behavior control. As a warning means for warning the driver by sound or display, 21 is a line pressure actuator for controlling the line pressure of a continuously variable transmission (hereinafter simply abbreviated as CVT), and 22 is a CVT gearshift. This is a shift actuator that controls the ratio.

Next, the signals of the sensors or switches 1 to 11 on the input side are input, and the devices 1 on the output side are input.
The ECU 30 as a control unit that outputs a control signal to the control units 2, 14 to 22 will be described.

The ECU 30 includes an ABS 13, an electronic braking force distribution device 23 for distributing a braking force applied to the rear wheels so that the rear wheels do not lock during braking, and A traction control system 24 that suppresses the phenomenon of slipping by controlling the driving force or braking force on each wheel, a vehicle stability control device 25 that suppresses / avoids yaw rate behavior such as drift-out and spin, and a CVT CVT for controlling the line pressure actuator 21 and the shift actuator 22 to control the behavior of the vehicle
And a control device 26.

Next, the input and output of the signals of the respective devices will be described. The signals from the vehicle speed sensor 1 are used to calculate the wheel speed and the estimated vehicle speed in the wheel speed calculator 27 and the estimated vehicle speed calculator 28. The signal from the strap lamp switch 6 is input to a stop lamp state determination unit 29, from which it is input to the ABS 13, the electronic braking force distribution device 23, the traction control system 24, and the vehicle stability control device 25.

The signals from the engine speed sensor 7, the throttle opening sensor 5 and the shift position detecting sensor 8 are supplied to an engine speed calculating unit 31, a throttle opening information input unit 32 and a shift position judging unit 33, respectively. From which the traction control system 24, the vehicle stability control device 25 and the CVT
It is input to the control device 26.

Further, the signals from the steering angle sensor 2, the yaw rate sensor 3, the lateral G sensor 4 and the MC hydraulic pressure sensor 9 are supplied to the steering angle calculating section 34, the yaw rate calculating section 35, respectively.
The steering angle, the yaw rate, the lateral acceleration and the MC hydraulic pressure are calculated by the lateral G calculating unit 36 and the MC hydraulic pressure calculating unit 37, and the vehicle stability control device 25 and the CVT control device 26 are calculated.
Is input to

In addition, the signal of the reservoir liquid level switch 10 is input to the traction control system 24 and the vehicle stability control device 25 via the liquid level determination unit 38, and the accelerator opening sensor 11
Is input to the CVT controller 26 via the accelerator opening calculator 39 (or the accelerator opening information acquisition unit).

The ABS 13 calculates a control amount from each signal, and outputs an ABS lamp 12, a pressurizing motor 14, a front solenoid valve 15, a rear solenoid valve 1
6 to control these. Further, the electronic braking force distribution device 23 controls the rear solenoid valve 16.

The above traction control system 2
Reference numeral 4 outputs signals to the front solenoid valve 15, the rear solenoid valve 16, the pressurizing motor 14, the TSW solenoid valve 17, and the engine controller 19 to control them.

The stability control device 25 includes an engine controller 19, front and rear solenoid valves 15, 16, a pressurizing motor 14, TSW and A
SW solenoid valves 17, 18 and alarm device 20
And outputs a signal to control these.

Further, the CVT controller 26 outputs signals to the line pressure actuator 21 and the speed change actuator 22 to control them. FIG. 2 shows a toroidal CVT 40 as an example of the CVT.
Numeral 0 is interposed between an input shaft 42 from the engine 41 and a drive wheel 43 (front wheel or rear wheel), and continuously changes the rotational power of the engine 41.

The toroidal CVT 40 includes a pair of input disks 44, 44 integrally connected to an input shaft 42 from the engine 41, an output disk 45 loosely fitted to the input shaft 42, These input disks 4
A friction roller 46 for transmitting torque by making frictional contact with the disk 4 and the output side disk 45, and a change mechanism (not shown) for changing the tilt angle of the friction roller 46 by hydraulic operation. ing.

The rotational power of the engine 41 input from the input shaft 42 is changed by changing the tilt angle of each of the friction rollers 46 to change the turning radius of the contact point with each of the disks 44 and 45. The transmission is continuously variable and transmitted to the drive wheels 43 via the output disk 45.

FIG. 3 shows the toroidal CVT4 shown in FIG.
A shift diagram of 0 is shown, with the horizontal axis representing vehicle speed and the vertical axis representing target engine speed. The fraction in the figure indicates the accelerator opening. The shift diagram in FIG. 3 is stored in the CVT control device 26 as a shift map. Also,
The CVT control device 26 changes the engine speed so as to satisfy the demand for acceleration by operating the shift mode and the economy mode in which the speed is controlled so that the engine speed is fixed at the economic speed or the speed close to the best fuel economy. And a power mode set so that upshifting is difficult to be performed with an increase in vehicle speed and throttle opening.

(Attitude Stability Control) Next, the attitude stability control (behavior control) of the vehicle in the vehicle stability control device 25 or the CVT control device 26 will be described. The vehicle stability control device 25 or the CVT control device 26 includes an understeer control which is a control for avoiding understeer and an oversteer control which is a control for avoiding oversteer (however, the control includes the CVT control device 26 in the present embodiment).
Is not used, but is not limited to this).

The understeer control is executed when the control target yaw rate Trψ is larger than the actual yaw rate ψ.
It controls the gear ratio of the CVT 40, executes control to reduce the engine output, or applies braking force to the front wheel in turning or the rear wheel in turning. By such control, a vehicle moment is generated due to a decrease in centrifugal force due to a decrease in vehicle speed (restoration of cornering force) and a difference in braking force applied to each wheel, so that understeer can be avoided. Become.

On the other hand, in the oversteer control, specifically, when the control target yaw rate Tr # is smaller than the actual yaw rate ψ, control is performed to apply a braking force to the front wheels outside turning. By such control, a moment occurs in which the front portion of the vehicle turns outside, and oversteer can be avoided.

The vehicle stability control device 25 and the CVT
The behavior control by the control device 26 will be described in more detail. First, referring to the main routine shown in FIG.
The behavior control will be described.

In step S1, the ECU 30 reads signals from the various sensors 1 to 11 described above. Next, in step 2, the first target yaw rate based on the steering angle ψ (θ)
And a second target yaw rate ψ (G) based on the lateral acceleration.

Specifically, the first target yaw rate ψ (θ) is calculated based on the estimated vehicle speed V calculated by the estimated vehicle speed calculator 27 based on the signal from the wheel speed sensor 1 and the steering angle sensor 2.
And the steering angle θ calculated by the steering angle calculator 34 and calculated by the following formula (1).

Ψ (θ) = V × θ / {(1 + K × V ² ) × L} (1) where K is a stability factor, and K is μ
(Coefficient of friction) This is a constant obtained from turning the road. L is a wheel base.

On the other hand, the second target yaw rate ψ (G) is
The lateral acceleration Gy is computed by the lateral G computing unit 36 based on the estimated vehicle speed V and the signal from the lateral G sensor 4 according to the following equation (2).

Ψ (θ) = Gy / V (2) Next, in step S3, the second target yaw rate ψ (G)
It is determined whether or not the absolute value of is smaller than the absolute value of the first target yaw rate ψ (θ). This determination is based on the first and second
This is a step of determining which of the target yaw rates ψ (θ, G) is to be set as the control target yaw rate Trψ. The smaller the absolute value of the first and second target yaw rates ψ (θ, G), The control target yaw rate Tr # is set to control the behavior of the vehicle. Thus, if the determination in step S3 is NO, the process proceeds to step S4, and if the determination is YES, the process proceeds to another step S5.

In step S4, the first target yaw rate ψ (θ) is set as the control target yaw rate Trψ, and the deviation between the control target yaw rate Trψ and the actual yaw rate 検 出 detected by the yaw rate sensor 3 and calculated by the yaw rate calculator 35. Produce Δψ (θ).

In step S5, the second target yaw rate 第 (G) is set as the control target yaw rate Trψ. At this time, the control target yaw rate Tr # is corrected by taking the steering angle component into account according to the following equation (3). That is, Trψ = ψ (G) + a × k1 (3) Here, a = ψ (θ) -ψ (G). k1 is a variable.

Then, a deviation Δψ (θ, G) between the corrected control target yaw rate Trψ and the actual yaw rate ψ is produced. Thus, the second target yaw rate based on the lateral acceleration ψ
By correcting the steering angle component when (G) is the control target yaw rate Trψ, the intervention of the behavior control can be suppressed when the driver intentionally understeers (drive understeer). become.

That is, for example, when the vehicle is in the understeer state, the behavior of the vehicle with respect to the drive understeer which is intentionally performed by the driver to increase the driving force while keeping the steering angle constant and the steering of the driver is changed. There are two types of unsteered understeer that the driver does not follow.

Here, for example, when the second target yaw rate ψ (G) based on the lateral acceleration is set as the control target yaw rate Trψ, the lateral acceleration generated in the vehicle is the same in any of the above two types of understeer. Even in the case of the drive understeer, the behavior control is performed. Therefore, when the second target yaw rate ψ (G) is set as the control target yaw rate, the steering angle component is corrected,
Behavior control will be performed only when the driver is turning the steering wheel (steering wheel), behavior control will not be performed in drive understeering, and behavior control will be performed only in the case of understeering not intended by the driver. Can be.

In the above equation, the value of k1 is a value having a characteristic that changes with respect to the lateral acceleration, for example, as shown in FIG. That is, the lateral acceleration is small
If the road surface is in a low μ area (such as an ice surface) or the lateral acceleration is large (in a high μ area), a small value is set, and the correction ratio of the steering angle component is reduced.

This is because, for example, if the value of k1 is increased in the low μ region, the following inconvenience occurs. That is, since the rudder is hardly effective in the low μ range, the driver normally performs a steering operation with a relatively large rudder angle. In such a case, if the value of k1 is increased to increase the correction ratio of the steering angle component, the deviation between the control target yaw rate Trψ and the actual yaw rate ψ increases, and the control amount of the behavior control,
For example, the control amount increases. As a result, the vehicle behavior after performing the behavior control may become too large in the reverse direction, and it may be difficult to correct the behavior in the reverse direction.

The reason why the value of k1 is reduced in the high μ region is that, for example, in the high μ region, the grip force of the tire is sufficiently obtained, so that the value of k1 is increased to increase the steering angle component. This is because when the value of is increased, the behavior control starts too early. In other words, in such a high μ region, appropriate control intervention is realized without increasing the correction ratio of the steering angle component. Therefore, in the high μ region, the value of k1 is reduced.

On the other hand, when the lateral acceleration is medium to low (medium μ region), it corresponds to the road surface μ when the road surface is in a snow compaction state, and there is a high possibility that side slip occurs. The correction ratio of the angle component is increased so that the behavior control is performed early.

As described above, by changing the value of k1 according to the lateral acceleration, the intervention of the behavior control at an appropriate timing can be realized. Then, in the above step S4 or step S5, the control target yaw rate T
When a deviation Δψ (θ, G) between rψ and the actual yaw rate 演 is produced, the process moves to the next step S6, and this step S6 is performed.
And a threshold value THO for determining whether or not to perform oversteer control.
S, threshold value THCUS for determining whether to perform CVT control in understeer control, threshold value THEUSUS for determining whether to perform engine control in understeer control, and threshold value THUS for determining whether to perform brake control in understeer control. Set each. Where THUS
>THEUS> THCUS.

That is, the threshold value THCUS for starting the behavior control by the CVT 40 is set to the minimum value, and the engine 41
Is set to the next largest value, and the threshold value THUS for starting the behavior control by the braking force (brake) is set to a larger value. The threshold value setting process will be described later using a subroutine.

Next, in step S7, behavior control by the CVT 40 is executed. The behavior control by the CVT 40 will be described later using a subroutine of FIG. Next, in step S8, behavior control by the engine 41 is executed.
The behavior control by the engine 41 will be described later using a subroutine of FIG. Next, in step S9, behavior control based on the braking force is executed. The behavior control using the braking force will be described later using a subroutine of FIG.

The above is the description of the main routine. Next, behavior control (control of returning understeer to neutral steer) by the CVT 40 will be described with reference to the flowchart of FIG. This flowchart is a process corresponding to step S7 in FIG.

At step C1, the control target yaw rate Tr
It is determined whether the difference Δ 偏差 (θ) between の and the actual yaw rate 大 き い is greater than a threshold value THCUS of the behavior control intervention by the CVT 40, and when Δψ (θ)> THCUS is determined as YES (as the first predetermined state) When the understeer state is detected), the process proceeds to the next step C2. On the other hand, when the determination is NO, the process in the subroutine ends, and the process returns to the main routine in FIG.

At step C2, it is determined whether or not the yaw rate acceleration is equal to or less than a predetermined value. This is for the purpose of preventing erroneous intervention of control, and it is determined whether or not the vehicle has actually changed the behavior by a predetermined amount or more. When the determination is YES, the process proceeds to step C3. On the other hand, when the determination is NO, the process in the subroutine ends, and the process returns to the main routine in FIG.

Next, at step C3, it is determined whether or not the vehicle is oversteering. This is because it is conceivable that oversteer and understeer, in which the vehicle moves to the outside of the circuit while rotating in the turning direction, occur simultaneously. In such a case, the oversteer is first avoided to avoid the oversteer. Need to be fixed. When the determination is YES, the process proceeds to step C5, and when the determination is NO, the process proceeds to step C4.

At step C4, it is determined whether or not the brake is not operated. This is because when the driver is performing the brake operation, the driver clearly states that the driver intends to stop, so that the braking control by the brake is given the highest priority. If the determination in step C4 is NO, the process proceeds to the next step C5, and if the determination is YES, the process proceeds to another step C6.

In step C5, the ECU 30 sets the CV
In addition to prohibiting the behavior control by T40, the CVT 40 is controlled to shift up to reduce the gear ratio.
(See FIG. 3). The line pressure is increased by the CVT controller 26 via the line pressure actuator 21 to increase the pressure at which the friction roller 46 comes into frictional contact with each of the disks 44 and 45. That is, the control of the CVT 40 on the shift-up side reduces the sensitivity of the CVT 40 with respect to the force transmitted from the vehicle side to the outer CVT 40, and increases the fastening force of the friction roller 46 by increasing the line pressure to reduce slip. To protect CVT 40.

Next, at step C6, it is determined based on the input from the accelerator opening sensor 11 whether or not the accelerator pedal is depressed (acceleration request is present). If YES (when the accelerator pedal is depressed), the behavior control by the CVT 40 is performed. Therefore, the processing in the subroutine ends and the process returns to the main routine of FIG. 4. On the other hand, when the determination is NO (when the accelerator is OFF or the accelerator is ON to a constant state), the next step C7
Move to In this step C7, it is determined whether or not the accelerator is OFF. When the determination is YES, the process proceeds to the next step C8, while when the determination is NO (when the accelerator ON as the second predetermined state is detected), the process proceeds to another step C13. Transition.

In the above-described step C8, the control amount of the CVT 40 is produced. This control amount is a value in the direction of shifting down the CVT 40, that is, in the direction of increasing the speed ratio of the CVT 40 and applying engine braking. Next, step C
At 9, the CVT control device 26 executes the CVT control (behavior control by the CVT 40) in which the CVT 40 is controlled to the downshift side via the shift actuator 22.

That is, the vehicle driving force is obtained by multiplying the engine driving force by the speed ratio. By increasing the speed ratio when the accelerator is turned off, the engine braking force increases, thereby reducing the vehicle speed. , To eliminate understeer.

Next, in step C10, it is determined whether or not the engine speed is equal to or higher than a predetermined high speed. When the determination is NO, the process proceeds to the next step C11, and when the determination is YES, the process proceeds to another step C12. This is to stop the further behavior control by the CVT 40 when the engine speed is equal to or higher than the predetermined high speed, and to prevent the engine speed from being excessively increased. Alternatively, after the shift control by the CVT 40, it may be determined whether or not the change amount of the engine speed difference is equal to or more than a predetermined value, and it is determined whether the change rate of the engine speed is equal to or more than a predetermined value. You may.

Next, at step C11, it is determined whether or not the gear ratio of the CVT 40 is equal to or greater than a predetermined value. When the determination is NO, the subroutine is terminated and the process returns to the main routine of FIG. Move to C
Update of the behavior control by the VT 40 is prohibited. That is, the process proceeds to step C12 in order to prevent a change in behavior due to sudden acceleration at the time of re-acceleration operation of the driver due to an excessive increase in engine speed and to prevent the engine from stopping.

Here, instead of the configuration in which it is determined in step C11 whether the gear ratio of the CVT 40 is equal to or more than a predetermined value,
You may comprise so that it may determine whether the change amount of the gear ratio of CVT40 is more than a predetermined value.

On the other hand, in the above-mentioned step C13, it is determined whether or not the vehicle speed is accelerating. When the determination is NO (during the steady running of the vehicle or the decelerated running of the vehicle), the process proceeds to the next step C14. On the other hand, when the determination is YES, the process shifts to step C8 described above. Note that, instead of the process of shifting to step C8 when the determination is YES, the behavior control by the CVT 40 may be stopped.

In step C14, the control amount of the CVT 40 is calculated. This control amount is a value in the direction of shifting up the CVT 40, that is, in the direction of decreasing the speed ratio of the CVT 40. Next, at step C15, CVT control (CVT4) in which the CVT control device 26 controls the CVT 40 to the upshift side via the speed change actuator 22.
0).

That is, the vehicle driving force is obtained by multiplying the engine driving force by the gear ratio, and the accelerator O as the second predetermined state is set.
When the N state, the steady running state of the vehicle, or the decelerated running state of the vehicle is detected, the vehicle driving force (driving torque) is reduced by reducing the gear ratio, thereby reducing the vehicle speed and reducing the understeer. It will be resolved.

Next, at step C16, it is determined whether or not the engine speed is equal to or lower than a predetermined rotation. When the determination is NO, the process proceeds to the next step C17, and when the determination is YES, the process proceeds to step C12. This is to stop further behavior control by the CVT 40 when the engine speed is equal to or lower than the predetermined low speed, thereby preventing the engine from stopping.

Next, at step C17, it is determined whether or not the speed ratio of the CVT 40 is equal to or less than a predetermined value. When the determination is NO, the subroutine is terminated and the process returns to the main routine of FIG. In order to achieve the above, the process proceeds to step C12 described above, and updating of the behavior control by the CVT 40 is prohibited.

That is, in this step C12, in the areas A and B shown in FIG. 3, the update of the behavior control by the CVT 40 is prohibited. The above is the description of the behavior control by the CVT 40. Next, referring to the subroutine of FIG.
The behavior control (control for returning the understeer to the neutral steer) by the engine 41 will be described. This subroutine is a process corresponding to step S8 in FIG.

In step E1, the THEUS sets the first
Deviation Δψ between target yaw rate ψ (θ) and actual yaw rate ψ
It is determined whether it is larger than (θ). That is, it is determined whether or not to perform the engine control in the understeer control.

In the determination as to whether or not to perform the engine control, even if the second target yaw rate ψ (G) is selected as the target yaw rate in step S3 (see FIG. 4), the first target yaw rate ψ The determination is made based on the value of (θ).

This is for the following reason. That is, since the steering angle signal reflects the driver's will in a solid manner, if the behavior control is performed with the first target yaw rate ψ (θ) as the control target yaw rate Trψ, the behavior control usually reflects the driver's will. It starts to reflect properly and starts properly.

In the understeer control, deceleration of the vehicle is effective for avoiding understeer. For this reason, if the vehicle is decelerated by lowering the engine output early, effective understeer avoidance is performed. Will be able to do it.

Further, since the lateral acceleration and the yaw rate are substantially proportional, the difference between the value of the second target yaw rate ψ (G) based on the lateral acceleration and the value of the actual yaw rate ψ is small. Since the value of に な る becomes unstable in the case of understeer, if the second target yaw rate ψ (G) is set as the control target yaw rate Trψ, it becomes difficult to perform appropriate control intervention. For the reasons described above, the engine control start determination uses the first target yaw rate 制 御 (θ) as the control target yaw rate Trψ.

Then, in step E1, YE
If S is determined, the process proceeds to the next step E2, while NO
When the determination is made, the processing of the subroutine ends, and the process returns to the main routine of FIG. In step E2, it is determined whether the yaw rate acceleration is equal to or less than a predetermined value.
This is for the purpose of preventing erroneous intervention of control, and it is determined whether or not the vehicle has actually changed the behavior by a predetermined amount or more. When the determination is YES, the process proceeds to step E3, and when the determination is NO, the process proceeds to another step E7 to prohibit engine control (behavior control by the engine) and then return to the main routine of FIG.

In step E3, it is determined whether or not the vehicle is oversteering. This is because it is conceivable that oversteer and understeer, in which the vehicle moves to the outside of the circuit while rotating in the turning direction, occur simultaneously.In such a case, first, oversteer is avoided to avoid oversteer. I need to fix my posture. So, YE
When the S determination is made, the process proceeds to step E7 to prohibit the behavior control by the engine, and then the process returns to the main routine of FIG. 4, while when the NO determination is made, the process proceeds to step E4.

In step E4, it is determined whether the brake is not operated. This is because when the driver is performing the brake operation, the driver clearly states that the driver intends to stop, so that the braking control by the brake is given the highest priority. When the determination is YES, the process proceeds to the next step E5, where an engine suppression control amount is produced to perform engine control.

Then, the process proceeds to a step E6, in which a signal is output to the engine controller 19 to execute the engine control, that is, the engine output is reduced, the speed ratio of the CVT 40 is reduced, and the line pressure is controlled via the line pressure actuator 21. To increase the pressure at which the friction roller 46 comes into frictional contact with each of the disks 44 and 45. That is, CV
By controlling the shift up side of T40, the C
The sensitivity of the CVT 40 to the force transmitted to the VT 40 is reduced, and the friction roller 46 is increased by increasing the line pressure.
To prevent slippage and protect the CVT 40.

On the other hand, if NO is determined in the step E4, the process shifts to the step E7 to inhibit the engine control. Upon completion of the processing in steps E6 and E7, the process returns to the main routine of FIG. The above is the engine 41
Next, behavior control (control of returning understeer or oversteer to neutral steer) by a braking force (brake) will be described with reference to a subroutine of FIG. This subroutine is a process corresponding to step S9 in FIG.

First, in step B1, it is determined whether or not oversteer control is to be performed. This oversteer control is determined in step S of the main routine (see FIG. 4).
4 or the yaw rate deviation Δψ calculated in S5
This is performed by determining whether (θ, G) is greater than the oversteer threshold THOS. Thus, YE
At the time of S determination, the process proceeds to the next step B2, in which the braking amount applied to the outer front wheel, that is, the front wheel outside in the yaw rate rotation direction, in order to avoid oversteer is determined according to the yaw rate deviation Δψ (θ, G). Set.

Next, at step B3, prior to the behavior control by the brake, the CVT control device 26 lowers the speed ratio of the CVT 40 via the speed change actuator 22 and controls the line pressure increase via the line pressure actuator 21. The pressure at which the friction roller 46 comes into frictional contact with each of the disks 44 and 45 is increased. In other words, the control of the CVT 40 on the shift-up side reduces the sensitivity of the CVT 40 to the force transmitted from the wheel side to the CVT 40, and increases the fastening force of the friction roller 46 by increasing the line pressure to eliminate slip. , CVT 40.

Next, in step B4, braking force control (behavior control by brake) is executed based on the set control amount. This is performed by controlling the pressurizing motor 14, the front and rear solenoid valves 15, 16 and the TSW and ASW solenoid valves 17, 18, respectively. Next, the process proceeds to step B5, and after the end of the oversteer control is determined, the process returns to the main routine of FIG. The details of step B5 will be described later.

On the other hand, if the determination in step B1 is NO, the process proceeds to step B6. In step B6, it is determined whether or not to start the understeer control. When the determination is YES, the process proceeds to step B7, while when the determination is NO, the process in the subroutine is terminated and the process returns to the main routine in FIG. Step B7 above
It is determined whether the understeer is small. If smaller, the process proceeds to step B8, while if larger, the process proceeds to step B9.

In step B8, the braking amount of the inner front wheel is calculated. On the other hand, in step B9, the braking amount of the inner rear wheel is calculated. This is because when the understeer is small, it is considered that the front wheel has a grip force,
The application of the braking force to the front wheels has better braking efficiency, that is, the vehicle can be decelerated more efficiently than the application of the braking force to the rear wheels. Therefore, when the understeer is small, the understeer control can be performed reliably and quickly by braking the inner front wheel. On the other hand, when the understeer is large, it is considered that there is no grip force of the front wheels, so that the braking force is applied to the inner rear wheels.

Next, in step B10, prior to the behavior control by the brake, the CVT control device 26 lowers the speed ratio of the CVT 40 via the speed change actuator 22,
The line pressure is controlled to increase through the line pressure actuator 21 to increase the pressure at which the friction roller 46 comes into frictional contact with each of the disks 44 and 45. In other words, the control of the CVT 40 on the shift-up side reduces the sensitivity of the CVT 40 to the force transmitted from the wheel side to the CVT 40, and increases the fastening force of the friction roller 46 by increasing the line pressure to eliminate slip. , CVT 40.

Next, in step B11, braking force control (behavior control by brake) is executed based on the calculated braking amount.

Then, in the next step B12,
An understeer control end determination is made. This is performed by determining whether or not the yaw rate deviation Δψ (θ, G) has become smaller than the threshold value THUS. Thus, when the determination in step B12 is NO, step B11
On the other hand, when the determination is YES, the next step B
Go to step 13.

In step B13, the behavior control by the brake is terminated, and the CVT 40 is prepared for the next acceleration.
To the downshift side, and the control characteristics of the CVT 40 are changed for only a predetermined time (for example, about 10 to 20 seconds) in the power mode (the engine speed is changed based on the driver's acceleration request to increase the vehicle speed and the throttle opening). The mode is changed to a mode focusing on acceleration, which is set so that upshifting is difficult to be performed, and the processing in the subroutine is completed.
FIG. 4 returns to the main routine.

The above is the description of the behavior control based on the braking force. Next, with reference to the flowchart of FIG. 9, the process of determining the start of the brake control in the understeer control will be described. Note that the flowchart in FIG. 9 corresponds to step B6 in the subroutine in FIG.

In this control start determination, the control is started not only based on whether the yaw rate deviation Δψ (θ, G) exceeds the threshold value THUS, but also when other conditions are satisfied. Like that.

First, in step D1, it is determined whether or not the yaw rate deviation Δψ (θ, G) is larger than the understeer threshold value THUS.
On the other hand, when the determination is NO, the process proceeds to another step D3.

In step D2, it is determined whether the acceleration of the actual yaw rate ψ is equal to or less than a predetermined value. This aims at preventing erroneous intervention of the control similarly to the steps C2 and E2 (see FIGS. 6 and 7).

Then, in step D3, it is determined whether or not the steering wheel speed is equal to or more than a predetermined value in the increasing turning direction. If YES, the process proceeds to the next step D5, while if NO, the process proceeds to step D7. Then, the non-control process ends, and the process returns to the flowchart of FIG. 8 (corresponding to NO determination in step B6). Then, the above step D
In FIG. 5, as shown in FIG. 10, the value of the first target yaw rate 値 (θ) is larger than twice the value of the actual yaw rate ψ, and the first target yaw rate ψ (θ) −the actual yaw rate ψ
It is determined whether or not the value Δψ (θ) is equal to or greater than a predetermined value. If the determination in step D5 is NO, the process proceeds to step D6, in which it is determined whether the acceleration of the actual yaw rate ψ is equal to or less than a predetermined value and Δψ (θ) is equal to or more than a predetermined value.
When the determination is made, the process proceeds to step D7, and the control is deactivated.

Step D5 is to determine whether the deviation between the first target yaw rate {(θ) and the actual yaw rate 大 き い is large (see FIG. 1).
0), and the step D6 is the first target yaw rate ψ
It is determined whether or not the speed of the spread of the deviation between (θ) and the actual yaw rate ψ is high (see FIG. 11). If YES is determined in step D5 or step D6, the process proceeds to step D4. Then, understeer brake control is started (corresponding to YES determination in step B6).

That is, if the behavior control is started only when the yaw rate deviation Δψ (θ, G) is larger than the threshold value THUS, the understeer state is intentionally set by the driver like the drive understeer. In this case, the yaw rate does not increase in accordance with the driver's intention, and the vehicle does not behave as intended by the driver, and the vehicle is understeered. Only the control is performed.

Next, a description will be given, with reference to the explanatory diagram of FIG. 12, of the determination of the start of oversteer control (the content of step B1 in FIG. 8). As described above, the start determination of the oversteer control is performed by setting the smaller absolute value of the first and second target yaw rates ψ (θ, G) as the control target yaw rate Trψ as the control target yaw rate. The deviation Δψ (θ, G) between Trψ and the actual yaw rate ψ is
The determination is made based on whether or not the threshold value is larger than the oversteer threshold value THOS.

For example, as shown in FIG. 7, when the absolute value of the second target yaw rate ψ (G) is smaller than the absolute value of the first target yaw rate ψ (θ),
Oversteer control is performed using (G) as the control target yaw rate Tr # (see T1 in FIG. 12).

For example, when the driver performs counter-steering to avoid such oversteer, the value of the first target yaw rate ψ (θ) is larger than the value of the second target yaw rate ψ (G). May be smaller. At this time, the control target yaw rate Trψ is changed to the second target yaw rateψ.
(G) to the first target yaw rate ψ (θ) (FIG. 12
T2).

When the counter steer is performed in this manner, the value of the actual yaw rate ψ becomes smaller than the value of the second target yaw rate ψ (G) with the change of the first target yaw rate ψ (θ). Here, for example, if the second target yaw rate ψ (G) is kept at the control target yaw rate Trψ, the oversteer control is changed to the understeer control. If the understeer control is performed in this way, the behavior of the vehicle is still oversteer, and the effect of the countersteer does not occur despite the driver performing countersteering, that is, oversteering is promoted. Control. However, the first and second
If the smaller one of the target yaw rates ψ (θ, G) is set as the control target yaw rate Trψ, the oversteer control is continuously performed even when the counter steer is performed, and the above-described disadvantage is solved.

The value of the first target yaw rate ψ (θ) passes through the neutral point, and the sign of the value of the first target yaw rate ψ (θ) is different from the sign of the value of the second target yaw rate ψ (G). Sometimes, the value of the control target yaw rate Trψ is kept constant at a predetermined value.
(See T3 in FIG. 12). Thereafter, if the values of the first and second target yaw rates ψ (θ, G) have the same sign, the first
In FIG. 12, the value of the second target yaw rate ψ (G) is set to the control target yaw rate Trψ (T in FIG. 12).
4).

As described above, the value of the control target yaw rate Tr # is maintained at a constant value in order to avoid an increase in the control gain at the time of a state transition where the steering angle exceeds the neutral point. It is. Further, for example, if the value of the first target yaw rate ψ (θ) is directly used as the control target yaw rate Trψ, the control amount becomes large, and the vehicle may spin in the reverse direction. As described above, when the vehicle spins in the reverse direction, it is difficult to avoid the spin in the reverse direction. Therefore, when the values of the first and second target yaw rates ψ (θ, G) have different signs, , The control target yaw rate Tr # is held at a predetermined value.

If the predetermined value is set to, for example, a neutral point, the vehicle will not cause yaw behavior thereafter. Therefore, the predetermined value is a value offset from the neutral point.

(Counter Convergence Control) As described above, in the case of oversteering, the driver may perform countersteering, and even in such a case, control is performed to properly avoid oversteering. However, by performing the brake control by the behavior control, the behavior of the vehicle becomes larger than the steering by the steering wheel. As a result, for example, oversteering in the reverse direction may occur due to a delay in returning the steering wheel after the driver performs countersteering. As a result, the yaw rate and the behavior of the vehicle may not converge.

In order to prevent such oversteering in the reverse direction, control is performed to apply a braking force to the front wheels in turning. That is, FIG. 13 shows a flowchart of the convergence control after the counter steer. In this control, first,
In step J1, it is determined whether the oversteer control is being performed or within a predetermined time after the control. When the determination is YES, the process proceeds to the next step J2, and when the determination is NO, the process returns.

At step J2, a counter determination is made as to whether or not counter steering has been performed. this is,
For example, the determination may be made using the fact that the value of the first target yaw rate ψ (θ) based on the value of the actual yaw rate と and the steering angle is inverted or that the steering angular velocity is inverted. And YE
When the determination is S, the process proceeds to step J3, while when the determination is NO, the process returns.

In step J3, it is determined whether the counter value is large. This may be determined based on, for example, whether the oversteer state before performing countersteering is large, or whether the steering angular velocity of the steering wheel during performing countersteering is large. When the determination is YES, the process proceeds to step J4, and when the determination is NO, the process returns.

At step J4, it is determined whether or not the steering angular velocity has been reversed. That is, it is determined whether or not the steering wheel is returned after the counter steer is performed. When the determination is YES, the process proceeds to step J5, and when the determination is NO, the process returns.

In step J5, it is determined whether or not the actual yaw rate ψ follows the change in the steering angle. That is, if the actual yaw rate ψ follows the change in the steering angle, the yaw rate behavior is considered to be converging, so that the braking force is not applied to the front wheels inside the turning. Even if the braking force is applied, the application of the braking force may be stopped when the actual yaw rate ψ follows the change in the steering angle.

Then, when the determination is NO, the process proceeds to step J6, in which the braking force is applied to the front wheel inside the turn, and when the determination is YES, the process returns. Such control makes it possible to prevent the vehicle from oversteering in the reverse direction after performing countersteering.

(Setting of Understeer Threshold) Next, FIG.
The setting of the understeer threshold THUS (threshold for the behavior control by the brake) in step S6 in the main routine of FIG. The understeer threshold value THUS is set by determining a basic threshold value and correcting the basic threshold value.

First, as shown in FIG. 14, step P1
In, a basic threshold is set. This basic threshold value may be a predetermined constant. Next, in step P2, if the steering wheel is turned back, the threshold value is increased as the steering speed is increased, and the intervention of the behavior control is suppressed, that is, the intervention of the behavior control becomes difficult. This is because the steering wheel is turned back in spite of the understeer, and it is considered that the driver is intentionally operating.When such a driver is driving intentionally, The reason is that the intervention of the behavior control is suppressed and left to the driver's operation. As a result, it is possible to prevent the behavior control intervention and the driver's operation from interfering with each other.

Then, in step P3, as the fluctuation of the actual yaw rate (change of the actual yaw rate) increases, the threshold value is increased to suppress the control intervention. This is because understeer is avoided if the yaw rate is increasing. Conversely, if control is intervened early in such a case, the yaw rate will change further, and oversteer may occur. Therefore, in order to avoid erroneous control intervention in such a case, the threshold value is increased.

In step P4, when the steering wheel is in the vicinity of the neutral position, the threshold is raised to suppress the control intervention. This is because understeering usually occurs when the steering wheel is turned, and it is not necessary to control understeering in the vicinity of the neutral position of the steering wheel. This is to avoid intervention.

In step P5, when the lateral acceleration is small (in the low μ region), the threshold value is lowered, and the control intervention is accelerated. This is because the behavior control is started early in such a case, for example, because understeer tends to occur when the μ is low on a snowy road or the like.

In step P6, if the second target yaw rate ψ (G) drops by a predetermined value or more during the turn, the threshold value is lowered to speed up the control intervention. The purpose of this is to expedite the control intervention in the case where the road surface μ suddenly becomes small and the vehicle slips, for example, when the road surface is partially frozen. That is, when the road surface μ changes suddenly, the driver cannot operate the steering wheel, or it takes a long time to operate the steering wheel. Here, for example, if the behavior control is performed using only the first target yaw rate ψ (θ), the behavior control cannot be started because the first target yaw rate ψ (θ) does not change. . On the other hand, in this embodiment, since the behavior control is also performed using the second target yaw rate ψ (G) based on the lateral acceleration, accurate control can be performed early even for such a change in the road surface μ. become able to. Thus, the threshold value TH of the understeer brake control is set.
US is set.

(Setting of oversteer control threshold value)
The setting of the oversteer threshold value THOS in step S6 in the main routine of FIG. 4 will be described. The oversteer threshold THOS is also set by setting a basic threshold and correcting the basic threshold.

First, as shown in FIG.
In, a basic threshold is set. As shown in FIG. 16, the basic threshold value is set to a larger value as the vehicle speed V is lower. At a very low speed, the basic threshold value is set to a larger value.

Next, in step Q2, FIG.
As shown in (2), the higher the lateral acceleration is, the higher the threshold is, and the higher the vehicle speed is, the larger the correction is.
This is because, for example, in a region where the lateral acceleration is low, that is, in a low μ region, oversteering is likely to occur, so that the threshold value is lowered so that oversteer control is performed early. Further, when the lateral acceleration is high (high μ region) and the vehicle is traveling at high speed, the behavior changes quickly. For example, when the threshold value is lowered, erroneous intervention of the behavior control by the brake is likely to occur. Furthermore, a driver who can drive in a high μ region at a high vehicle speed is considered to be a driver who can sufficiently cope with a slight change in behavior of the vehicle,
In order to prevent interference between the behavior control by the brake and the driver's operation, the threshold value is increased in the lateral acceleration and high-speed range.

In step Q3, the smaller the steering angle of the steering wheel is, the higher the threshold value is set to suppress the control intervention. This is because, for example, even when the steering angle of the steering wheel is small, the direction of the vehicle and the direction of the steering angle may be reversed due to disturbance or the like, particularly on a snowy road. In such a case, the vehicle naturally runs stably without performing the behavior control,
Try to reduce control intervention.

In step Q4, the lower the steering speed of the steering wheel, such as when the steering wheel is turned back, the higher the threshold value, and the control intervention is suppressed. This is because the driver slowly returns the steering wheel, and thus it is considered that the driver can sufficiently avoid oversteer by his own operation without performing control intervention. Therefore, the threshold is increased to suppress the control intervention.

In step Q5, when the yaw rate overshoots, the threshold value is raised to suppress the control intervention. When the yaw rate overshoots, as shown in FIG. 18, when the steering wheel is returned from the steering wheel turning state to the neutral point, the actual yaw rate ψ overshoots even though the vehicle is not in an unstable state. In such a case, it is determined that the vehicle is oversteering. Therefore, the threshold value is increased to suppress control intervention.

In step Q6, when the fluctuation of the yaw rate is large, the threshold value is increased to suppress the control intervention. This is to prevent erroneous control intervention.

In step Q7, when it is determined that the front wheel drive vehicle in which the front wheels are the drive wheels is tack-in or counter-steer, the threshold is lowered to speed up the control intervention. Here, as the determination of the tack-in, for example, the steering angle is constant in a cut state, the shift speed is a low speed corresponding to the second speed or the third speed, and the throttle opening is reduced by returning the accelerator pedal. If the condition is satisfied, it may be determined that the tack-in is performed. on the other hand,
The counter steer is determined from the steering angle of the steering wheel.

In step Q8, if the correction for increasing the basic threshold value in each of the above steps is performed,
Since the value may become too large, the upper limit is increased. Thus, the threshold value THOS for the oversteer control is set.

(End Determination of Oversteer Control) Next, the determination of the end of oversteer control (step B5 in FIG. 8)
This will be described according to the flowchart shown in FIG. This is a control for the purpose of avoiding the interference between the operation of the driver and the behavior control while terminating the behavior control in a state where the behavior of the vehicle is stabilized.

First, in step U1, it is determined whether or not the steering wheel is stable in a straight running state, that is, whether or not the steering angle is stable in a substantially neutral position. When the determination is NO, the process proceeds to the next step U2.

In step U2, it is determined whether or not the steering wheel is further turned. When the determination is NO, the process moves to the next step U3.

In step U3, it is determined whether or not the difference between the second target yaw rate ψ (G) and the actual yaw rate ψ is stable below a predetermined value. That is, it is determined whether or not both values are sufficiently small and substantially coincide with each other,
When the determination is NO, the process moves to step U5.

If the determination in each of the above steps U1, U2, U3 is YES, the process shifts to step U4, ends the control, and returns. This is step U
In the determination of 1, since it is considered that the driver is operating the steering wheel calmly, there is no need to perform the behavior control, and if the behavior control is performed, the operation of the driver may interfere with the behavior control. Because there is. In addition, in the determination of step U2, since the driver operates the steering wheel in a direction that promotes oversteering, the driver intentionally oversteers and turns, or the vehicle is intentionally spun to avoid an accident, for example. This is because you may be trying to do so. In such a case, by ending the behavior control promptly, it is possible to prevent interference between the behavior control and the driver's operation. Further, in the determination of step U3, the second target yaw rate {(G)} and the actual yaw rate 略 substantially match, and the state is stable.
Since the behavior of the vehicle is in a stable state and there is no need to perform behavior control, the control is terminated.

On the other hand, in step U5, it is determined whether or not the estimated brake fluid pressure estimated from the braking amount in the behavior control is substantially equal to the pressure of the smart cylinder. That is, it is determined whether or not the braking force control is not substantially performed and it is considered that the behavior control may be terminated. If YES is determined in step U5, the process proceeds to step U6, whereas if NO is determined, the process proceeds to step U9.

At step U6, it is determined whether the slip angle β is small. That is, it is determined whether or not skidding has occurred.
On the other hand, when the determination is NO, the process returns without terminating the control.

In step U7, the value of the second target yaw rate ψ (G), the value of the first target yaw rate ψ (θ),
It is determined whether or not the values of the actual yaw rate ψ are all equal to or less than a predetermined value. That is, it is determined whether or not the three values are smaller than the predetermined value and approximate to each other. In this determination, it is determined whether the vehicle is in a substantially straight-ahead state and the steering operation is not performed, and whether the behavior control is not required.
Is difficult to be satisfied in some cases, the determination is made to end the behavior even if the condition is looser than the condition in step U3. When the determination is YES, the process shifts to step U8 to determine whether or not the state in which the above condition is satisfied has elapsed for a predetermined time t1. That is, since it is conceivable that the above condition is satisfied by chance, it is determined whether the predetermined time t1 has elapsed. When the determination is YES, the process moves to step U12, ends the behavior control, and returns. When the determination is NO, the process returns without terminating the control. Then, in step U9,
It is determined whether or not the slip angle β is small. If the determination is YES, the process proceeds to step U10.

In step U10, two of the value of the second target yaw rate ψ (G), the value of the first target yaw rate ψ (θ), and the actual yaw rate 以下 are equal to or less than a predetermined value, and the remaining one is also a predetermined value. It is determined whether or not the value is far from the value. This is a looser condition than the condition in step U7. When the determination is YES, the process proceeds to step U11, and it is determined whether or not the predetermined time t2 has elapsed while the condition of step U10 is satisfied. Here, since the predetermined time t2 is a condition looser than the condition of step U7, the predetermined time t2 is set to a value larger than the predetermined time t1 in step U8. And YE
When the determination is S, the control is terminated in step U12 and the process returns.

On the other hand, the above steps U9, U10, U1
If NO is determined in step 1, the routine returns to continue the control. By continuing the control until the vehicle enters a stable running state, a behavior that may occur when the control end is determined based only on the deviation between the control target yaw rate Trψ and the actual yaw rate ψ, for example, It is possible to prevent the control from ending early.

It is effective to determine the end of the behavior control when the behavior control is required once after the behavior control is performed, for example, to avoid an obstacle. , The end and start of the control may be repeated in a short time to cause a change in the behavior with the end of the behavior control,
It is possible to prevent the stability of the driving operation from becoming unstable.

On the other hand, in a situation where the driver does not need control, by ending the behavior control early,
The behavior control and the driver's operation can be prevented from interfering with each other.

In short, according to the first aspect of the present invention,
A vehicle behavior control device including a control unit (see ECU 30) for estimating a traveling state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result, wherein the rotational power of an engine 41 is steplessly shifted. A CVT 40 is provided, and the control means controls the behavior of the vehicle by the CVT 40.

As described above, the above-described control means is controlled by the CVT 40
The vehicle behavior control is executed by changing the speed ratio of the vehicle and controlling the vehicle speed, thereby stabilizing the posture during turning of the vehicle. Therefore, the yaw rate behavior that cannot be sufficiently controlled by the engine 41 and the brake is impossible. Fine behavior control can be performed in a small area, ensuring running performance in this area,
Since a large change in driving force can be obtained with a small change ratio change, acceleration performance at the time of re-acceleration can be improved.

According to the second aspect of the present invention, the behavior control includes a behavior control using a brake (see step S9 in FIG. 4) and a C control.
The behavior control by the VT 40 (see step S7 in FIG. 4) is provided, and the behavior control by the CVT 40 is performed prior to the behavior control by the brake when the behavior control is interposed.

As described above, the above-described control means preferentially executes the behavior control by the CVT 40 when the behavior control is interposed, so that an excessive decrease in driving force due to the brake can be prevented, and
The posture control during turning of the vehicle can be stabilized by the behavior control by the VT 40.

According to the invention of claim 3, the behavior control is performed by the engine 41 (see step S8 in FIG. 4).
And behavior control by the CVT 40, and the CVT 40 takes precedence over the behavior control by the engine 41 when the behavior control is interposed.
Is used to control the behavior.

As described above, since the above-described control means preferentially executes the behavior control by the CVT 40 when the behavior control is interposed, it is possible to prevent an excessive drop in the engine speed.
The re-acceleration performance can be improved, and the attitude control during turning of the vehicle can be stabilized by the behavior control by the CVT 40.

According to the present invention, the behavior control includes the behavior control by the engine 41, the behavior control by the brake, and the behavior control by the CVT 40, and the intervention of the behavior control includes the behavior control by the CVT 40 and the behavior control by the engine 41. , And the priority is set in the order of the behavior control by the brake. As described above, since the suitable devices intervene in order according to the magnitude of the behavior, the behavior change can be suppressed smoothly, and the posture during the turning of the vehicle can be stabilized.

According to the fifth aspect of the present invention, the behavior control by the CVT 40 and the behavior control by the brake are provided, and the threshold value THUS for starting the behavior control by the brake is set to CVT.
The threshold value THCUS for starting the behavior control according to 40 is set to a small value.

As described above, the above-mentioned control means is the CVT 40
When the threshold value becomes equal to or higher than the threshold value THCUS for starting the behavior control by the CVT 40, the behavior control by the CVT 40 is started with priority, so that an excessive decrease in torque due to the brake can be prevented. The attitude control during turning of the vehicle can be stabilized by the behavior control according to.

According to the sixth aspect of the present invention, a behavior control by the CVT 40 and a behavior control by the engine 41 are provided, and the threshold THUSUS for starting the behavior control by the CVT 40 is compared with the threshold THEUSUS for starting the behavior control by the engine.
Is set to small.

As described above, the above-mentioned control means is controlled by the CVT 40
When the threshold value of the behavior control by the CVT 40 is equal to or more than the threshold value THCUS, the behavior control by the CVT 40 is started with priority. Therefore, the attitude control during vehicle turning is controlled by the behavior control of the CVT 40 while preventing the engine rotation from dropping. Can be achieved.

According to the seventh aspect of the present invention, there is provided a behavior control by the CVT 40, a behavior control by the engine, and a behavior control by the brake, and the threshold value THUS for starting the behavior control by the CVT 40 <the behavior control by the engine 41 is started. The threshold value THEUS is set to the threshold value THUS for starting the behavior control by the brake.

As described above, the above-mentioned control means is the CVT 40
When the threshold value THCUS (the minimum threshold value among the three threshold values) for starting the behavior control by the
Since the behavior control by 40 is started with the highest priority, a suitable device intervenes in order according to the magnitude of the behavior, so that the behavior change can be suppressed smoothly.

According to the eighth aspect of the present invention, the control means detects the first predetermined state (see the understeer state and the accelerator non-depressed state), reduces the driving torque by the CVT 40 (see step C9), Control the behavior of

As described above, when the first predetermined state is detected, the control means controls the speed ratio of the CVT 40 to reduce the driving torque, reduce the vehicle speed, and thereby perform the behavior control. The posture during turning can be stabilized.

According to the ninth aspect, the first predetermined state is set to an understeer state of the vehicle.
As described above, when the understeer as the first predetermined state is detected, the control means controls the speed ratio of the CVT 40 to reduce the driving torque and reduce the vehicle speed, thereby performing the behavior control. Thus, the posture can be stabilized when the vehicle turns.

According to the tenth aspect, the first predetermined state is set to the accelerator non-depressed state (N in step C6).
(See O determination). As described above, when the accelerator non-depressed state as the first predetermined state is detected, the control means controls the speed ratio of the CVT 40 to reduce the vehicle speed, thereby performing behavior control. In other words, when the accelerator is not in the non-stepped-on state (that is, when the accelerator is stepped on), it is difficult to expect the behavior control by the CVT 40, and therefore, the effect is obtained by other control.

According to the eleventh aspect of the present invention, the control means detects the second predetermined state (refer to the accelerator ON state, the steady running state, and the decelerating running state) and controls the CVT 40 to shift up (see step C14). Things.

As described above, when the second predetermined state is detected, the control means controls the CVT 40 to shift up (to decrease the gear ratio) to reduce the vehicle speed, thereby performing the behavior control. Therefore, the posture can be stabilized when the vehicle turns.

That is, the vehicle driving force is obtained by multiplying the engine driving force by the gear ratio, and the vehicle driving force is reduced by reducing the gear ratio when the second predetermined state is detected.
A stall condition results, which can reduce the vehicle speed.

According to the twelfth aspect of the present invention, the second predetermined state is set to an accelerator ON state (when a NO determination is made in step C7). As described above, when the accelerator ON state as the second predetermined state is detected, the control means
By controlling T40 on the upshift side (in a direction in which the gear ratio decreases), the driving torque is reduced, the vehicle speed is reduced, and the behavior control is performed, whereby the posture can be stabilized when the vehicle turns.

According to the thirteenth aspect of the present invention, the second predetermined state is the accelerator ON state (see the NO determination in step C7).
And a predetermined steady-state running state (see the NO determination in step C13). As described above, when the accelerator ON state as the second predetermined state and the steady running state of the vehicle are detected, the control means controls the CVT 40 to the upshift side (the direction in which the gear ratio decreases), and reduces the drive torque. In addition, the vehicle speed is reduced, thereby controlling the behavior, thereby stabilizing the posture when the vehicle turns.

According to the fourteenth aspect, the second predetermined state is the accelerator ON state (see the NO determination in step C7).
And a deceleration running state of the vehicle (refer to NO determination in step C13). As described above, when the accelerator ON state as the second predetermined state and the decelerating traveling state of the vehicle are detected, the control means controls the CVT 40 to the upshift side (the direction in which the gear ratio decreases) to reduce the driving torque. In addition, the vehicle speed is reduced, thereby controlling the behavior, thereby stabilizing the posture when the vehicle turns.

According to the fifteenth aspect of the present invention, the control means detects the accelerator OFF state and controls the CVT 40 to shift down (see step C8).
As described above, when the accelerator OFF state is detected, the control means controls the CVT 40 on the downshift side (in a direction in which the gear ratio increases) (see step C8), enhances the engine braking effect, reduces the vehicle speed, As a result, behavior control can be performed to stabilize the posture when the vehicle turns.

According to the sixteenth aspect of the present invention, when the control means detects a predetermined prohibition state (for example, the engine speed is higher than a predetermined high rotation and lower than a predetermined low rotation), the CVT 40
To stop the behavior control. As described above, when the predetermined prohibition state is detected, the control unit stops the behavior control by the CVT 40, so that an adverse effect on the behavior control can be prevented.

According to the seventeenth aspect, in the predetermined prohibited state, the engine speed is higher than the predetermined high speed (step C1).
0) and below a predetermined low speed (see step C16). As described above, when it is detected that the engine speed is equal to or higher than the predetermined high rotation speed and equal to or lower than the predetermined low rotation speed as the predetermined prohibition state, the control means stops the behavior control by the CVT 40. It is possible to prevent a change in behavior due to sudden acceleration during a re-acceleration operation of the driver, and to prevent an engine stop.

According to the eighteenth aspect of the present invention, the predetermined prohibition state is a state in which the change amount of the engine speed difference is set to a predetermined value or more after the shift control by the CVT 40. As described above, when it is detected that the change amount of the engine speed difference in the predetermined prohibition state is equal to or larger than the predetermined value, the control means sets the C to C
Since the behavior control by the VT 40 is stopped, it is possible to prevent the behavior change and the engine stop due to the sudden acceleration at the time of the driver's re-acceleration operation due to the excessive increase of the engine speed.

According to the nineteenth aspect, the predetermined prohibited state is such that the rate of change of the engine speed is set to a predetermined value or more. As described above, when it is detected that the rate of change of the engine speed in the predetermined prohibition state is equal to or higher than the predetermined value, the control means stops the behavior control by the CVT 40, so that the engine speed increases due to an excessive increase in engine speed. Thus, it is possible to prevent a change in behavior due to sudden acceleration at the time of re-acceleration operation of the driver, and to prevent an engine stop.

According to the twentieth aspect of the present invention, the predetermined prohibited state is a state in which the change amount of the speed ratio is set to a predetermined value or more. Thus, the CV in the predetermined prohibited state is
When it is detected that the change amount of the gear ratio at T40 is equal to or more than the predetermined value, the control means stops the behavior control by the CVT 40. It is possible to prevent a change in behavior due to sudden acceleration and an engine stop.

According to the twenty-first aspect, the predetermined prohibition state is set to a state where the throttle opening is increased. As described above, when the increase state of the throttle opening as the predetermined prohibition state is detected, the control means stops the behavior control by the CVT 40. That is, it is difficult to expect the behavior control by the CVT 40 when the throttle opening is increased, so that the effect is obtained by other control.

According to the twenty-second aspect, the predetermined prohibited state is set to a state in which behavior control by the engine 41 (see step C7) is started. in this way,
When detecting that the behavior control by the engine 41 in the predetermined prohibited state has been started, the control means stops the behavior control by the CVT 40. Therefore, it is possible to prevent the behavior control from becoming unstable due to a change in the gear ratio of the CVT 40 during the behavior control by the engine 41.

According to the twenty-third aspect of the present invention, the predetermined prohibition state is set to a start state of the behavior control by the brake (see step S9). As described above, when detecting that the behavior control by the brake in the predetermined prohibited state has been started, the control unit stops the behavior control by the CVT 40. For this reason, during the behavior control by braking, CV
It is possible to prevent the behavior control from becoming unstable due to a change in the speed ratio of T40.

According to the twenty-fourth aspect of the present invention, there is provided a vehicle behavior control device including control means (see ECU 30) for estimating a traveling state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result. A CVT 40 for continuously changing the rotational power of the engine 41 is provided, and when the convergence of the behavior control is determined, the control means controls the CVT 40 to the downshift side (see step B13).

As described above, when the convergence of the behavior control is determined, the control means controls the CVT 40 on the downshift side (in a direction in which the gear ratio increases), so that the acceleration performance after the end of the behavior control is secured early. be able to.

According to the twenty-fifth aspect of the present invention, there is provided a vehicle behavior control device provided with control means (see ECU 30) for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result. A CVT 40 for continuously changing the rotational power of the engine 41 is provided, and when the convergence of the behavior control is determined, the control means changes the CVT 40 to a direction in which upshifting is suppressed (step B1).
3).

As described above, when the convergence of the behavior control is determined, the control means changes the CVT 40 in the direction in which the upshift is suppressed (changes the engine speed based on the driver's acceleration request, and changes the vehicle speed and the throttle opening). This is a mode set so that it is difficult to perform an upshift with respect to the increase, and the power mode is controlled so as to emphasize acceleration, so that the acceleration performance after the end of the behavior control can be ensured.

According to the twenty-sixth aspect of the present invention, there is provided an automobile behavior control device provided with control means (see ECU 30) for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result. A CVT 40 for continuously changing the rotational power of the engine 41 is provided. When the intervention of the behavior control by the engine 41 is started, the CVT is controlled by the CVT.
The CVT 40 is controlled to shift up or the hydraulic pressure supplied to the CVT 40 is increased (step E6).
reference).

As described above, when the intervention of the behavior control by the engine 41 is started, the above-described control means operates the CVT4.
0 is shifted to the upshift side (see step E6) to reduce the gear ratio or increase the operating oil pressure supplied to the CVT 40, thereby preventing the CVT 40 from slipping and protecting the CVT 40. Can be planned.

According to the twenty-seventh aspect of the present invention, there is provided an automobile behavior control device including control means for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result. C to change power continuously
The VT40 is provided, and the behavior control by the brake (Step S
9), the control means (ECU 3
0) controls the CVT 40 to shift up or
This is for increasing the operating oil pressure supplied to the VT 40 (see step B10).

As described above, when the intervention of the behavior control by the brake is started, the above-described control means controls the CVT 40 to the upshift side to reduce the speed ratio or reduce the operating oil pressure supplied to the CVT 40. Since the pressure increase control is performed, the CVT 40 can be prevented from slipping, and the CVT 40 can be protected.

According to the twenty-eighth aspect of the present invention, there is provided an automobile behavior control device provided with control means (see ECU 30) for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result, A CVT 40 for continuously changing the rotational power of the engine 41 is provided, and at the time of the behavior control by the brake, the control means controls the gear ratio of the CVT 40 to the upshift side or increases the hydraulic pressure supplied to the CVT 40 (step B10). Then, the behavior control by the brake (see step B11) is started.

As described above, at the start of the intervention of the behavior control by the brake, the control means first controls the CVT 40 to the upshift side to reduce the speed ratio thereof, and
The sensitivity to the load transmitted to the T40 is reduced, or the hydraulic pressure supplied to the CVT 40 is increased to control the CVT.
Since the behavior control by the brake is started after the slippage of the CVT 40 is prevented, the CVT 40 can be further protected.

According to the twenty-ninth aspect of the present invention, there is provided an automobile behavior control device including control means (see ECU 30) for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result. A CVT 40 for continuously changing the rotational power of the engine 41 is provided, and when an oversteer state of the vehicle is detected (see YES determination in step B1),
The control means controls the CVT 40 to shift up (see step B3).

As described above, when the oversteer state of the vehicle is detected, the control means controls the CVT 40 to the upshift side to reduce the speed ratio. For this reason, when the oversteer state is eliminated by the behavior control using the brake, the braking force is applied to the outer front wheel while turning,
By lowering the sensitivity by controlling the CVT 40 to the upshift side, the reaction torque due to the braking of the wheels is reduced, the vibration transmission to the vehicle body is reduced, and the CVT 40 is reduced.
Can be protected.

In correspondence between the configuration of the present invention and the above-described embodiment, the control means of the present invention is the same as that of the ECU 30 of the embodiment.
In the same manner, the continuously variable transmission corresponds to the toroidal-type continuously variable transmission 40CVT, but the present invention is not limited to the configuration of the above-described embodiment.

For example, the continuously variable transmission may be a so-called belt type CVT having a pair of variable pulleys and a belt instead of a toroidal type. Each step in the above-mentioned flowchart constitutes each unit of detection, calculation, determination, control, or inhibition according to the processing content.

[0220]

The control means executes the behavior control of the vehicle by changing the speed ratio of the continuously variable transmission and controlling the vehicle speed, thereby stabilizing the posture during turning of the vehicle. In the region where the yaw rate behavior is small where sufficient control cannot be performed, fine behavior control can be performed, and the traveling performance and the acceleration performance at the time of re-acceleration can be enhanced in this region.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a behavior control device for an automobile according to the present invention.

FIG. 2 is a schematic explanatory view of a continuously variable transmission.

FIG. 3 is a shift diagram of a continuously variable transmission.

FIG. 4 is a main routine showing behavior control.

FIG. 5 is a diagram showing characteristics of a correction coefficient with respect to a lateral acceleration.

FIG. 6 is a subroutine showing behavior control by CVT.

FIG. 7 is a subroutine showing behavior control by an engine.

FIG. 8 is a subroutine showing behavior control by a braking force.

FIG. 9 is a flowchart showing the start of brake control in understeer control.

FIG. 10 is an explanatory diagram illustrating a relationship between an actual yaw rate indicating an understeer control start condition and a first target yaw rate.

FIG. 11 is an explanatory diagram showing a relationship between an actual yaw rate and a first target yaw rate showing understeer control start conditions different from those in FIG. 10;

FIG. 12 is an explanatory diagram showing an example of a change in a first target yaw rate, a second target yaw rate, a control target yaw rate, and an actual yaw rate.

FIG. 13 is a flowchart showing convergence control after counter steering.

FIG. 14 is a flowchart for setting a threshold value for brake control in understeer control.

FIG. 15 is a flowchart for setting a threshold value for oversteer control.

FIG. 16 is a diagram showing a relationship between a basic threshold value of oversteer control and a vehicle speed.

FIG. 17 is a diagram showing a correction amount according to a lateral acceleration and a vehicle speed with respect to a threshold value of oversteer control.

FIG. 18 is a diagram showing an overshoot state of an actual yaw rate.

FIG. 19 is a flowchart showing a determination of the end of oversteer control.

[Explanation of symbols]

 30 ECU (control means) 40 CVT 41 engine

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F02D 29/00 F02D 29/00 H 29/02 341 29/02 341 F16H 61/02 F16H 61/02 // F16H 59: 18 59:18 59:24 59:24 59:42 59:42 59:54 59:54 63:06 63:06 F term (reference) 3D041 AA32 AA33 AA36 AA40 AA48 AA49 AA54 AA64 AA66 AB01 AC01 AC19 AC28 AD00 AD02 AD04 AD10 AD31 AD51 AE00 AE03 AE04 AE36 AE39 AE43 3D045 BB40 CC01 EE21 FF42 GG00 GG01 GG25 GG26 GG28 3D046 BB21 BB28 BB31 GG02 GG06 HH00 DAH03 H05 HH02 HH05 HH07 HH08 HH13 H03 H03 H05 HHH EA01 EA09 EB03 EB04 EC01 3J052 AA04 CA21 CB11 EA04 EA05 FB33 GC64 HA13 KA01 LA01

Claims (29)

[Claims] 1. A vehicle behavior control device comprising a control means for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result, wherein a rotational power of an engine is continuously changed. A vehicle behavior control device provided with a continuously variable transmission, wherein the control means controls the behavior of the vehicle by the continuously variable transmission. 2. The behavior control according to claim 1, further comprising a behavior control by a brake and a behavior control by a continuously variable transmission, wherein the behavior control by the continuously variable transmission is performed prior to the behavior control by the brake when the behavior control is interposed. A vehicle behavior control device as described in the above. 3. The behavior control according to claim 1, further comprising: behavior control by the engine and behavior control by the continuously variable transmission, wherein the behavior control by the continuously variable transmission is performed prior to the behavior control by the engine when the behavior control is interposed. A vehicle behavior control device as described in the above. 4. The behavior control includes a behavior control by an engine, a behavior control by a brake, and a behavior control by a continuously variable transmission. The intervention of the behavior control includes behavior control by a continuously variable transmission, behavior control by an engine, braking by an engine. The behavior control device for an automobile according to claim 1, wherein the priority is set in the order of the behavior control by the vehicle. 5. A behavior control by a continuously variable transmission and a behavior control by a brake, wherein a threshold value of a behavior control start by a continuously variable transmission is set to be smaller than a threshold value of a behavior control by a brake. The vehicle behavior control device according to claim 1. 6. A behavior control by a continuously variable transmission and a behavior control by an engine, wherein a threshold value for starting the behavior control by the continuously variable transmission is set smaller than a threshold value for starting the behavior control by the engine. The vehicle behavior control device according to claim 1. 7. A behavior control using a continuously variable transmission, a behavior control using an engine, and a behavior control using a brake, wherein a threshold value for starting the behavior control using the continuously variable transmission <a threshold value for starting the behavior control using the engine. The vehicle behavior control device according to claim 1, wherein the threshold value is set to a behavior control start by a brake. 8. The vehicle behavior control device according to claim 1, wherein said control means detects the first predetermined state and controls the vehicle behavior by reducing the drive torque by means of a continuously variable transmission. 9. The vehicle behavior control device according to claim 8, wherein the first predetermined state is set to an understeer state of the vehicle. 10. The vehicle behavior control device according to claim 8, wherein the first predetermined state is set to a state in which the accelerator is not depressed. 11. The control means detects a second predetermined state,
The vehicle behavior control device according to claim 1, wherein the continuously variable transmission is controlled to shift up. 12. The vehicle behavior control device according to claim 11, wherein said second predetermined state is set to an accelerator ON state. 13. The vehicle behavior control device according to claim 11, wherein said second predetermined state is set to an accelerator ON state and a predetermined steady running state. 14. The vehicle behavior control device according to claim 11, wherein the second predetermined state is set to an accelerator ON state and a deceleration running state of the vehicle. 15. The control means detects an accelerator OFF state and controls the continuously variable transmission to a downshift side.
A vehicle behavior control device as described in the above. 16. The vehicle behavior control device according to claim 1, wherein said control means stops the behavior control by the continuously variable transmission when detecting a predetermined prohibited state. 17. The behavior control device for an automobile according to claim 16, wherein said predetermined prohibition state is such that an engine speed is set to a predetermined high rotation or higher and a predetermined low rotation or lower. 18. The vehicle behavior control device according to claim 16, wherein in the predetermined prohibition state, a change amount of an engine speed difference is set to a predetermined value or more after a shift control by the continuously variable transmission. 19. The behavior control device for an automobile according to claim 16, wherein in the predetermined prohibited state, the rate of change of the engine speed is set to a predetermined value or more. 20. The behavior control device for an automobile according to claim 16, wherein said predetermined prohibition state is set such that a change amount of a gear ratio is equal to or more than a predetermined value. 21. The vehicle behavior control device according to claim 16, wherein said predetermined prohibition state is set to a state in which the throttle opening is increased. 22. The vehicle behavior control device according to claim 16, wherein the predetermined prohibition state is set to a start state of behavior control by an engine. 23. The vehicle behavior control device according to claim 16, wherein said predetermined prohibition state is set to a state in which behavior control by a brake is started. 24. A behavior control device for an automobile, comprising: a control unit for estimating a running state of the vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result, wherein the rotational power of the engine is continuously changed. A behavior control device for an automobile, comprising a continuously variable transmission, wherein the control means controls the continuously variable transmission to a downshift side when the convergence of the behavior control is determined. 25. A behavior control device for an automobile, comprising: control means for estimating a running state of the vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result, wherein the rotational power of the engine is steplessly shifted. A vehicle behavior control device comprising a continuously variable transmission, wherein the control means changes the continuously variable transmission to a direction in which upshifting is suppressed when the convergence of the behavior control is determined. 26. A behavior control apparatus for an automobile, comprising: control means for estimating the running state of the vehicle and controlling the yaw rate behavior of the vehicle based on the estimation result, wherein the rotational power of the engine is continuously changed. A vehicle that is provided with a continuously variable transmission and controls the continuously variable transmission to the upshift side or increases the hydraulic pressure supplied to the continuously variable transmission when the intervention of the behavior control by the engine is started. Behavior control device. 27. A behavior control device for an automobile, comprising: a control unit for estimating a running state of the vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result, wherein the rotational power of the engine is continuously changed. A vehicle that has a continuously variable transmission and controls the continuously variable transmission to the upshift side or increases the hydraulic pressure supplied to the continuously variable transmission when the intervention of the behavior control by the brake is started. Behavior control device. 28. A behavior control device for an automobile, comprising: control means for estimating the running state of the vehicle and controlling the yaw rate behavior of the vehicle based on the estimation result, wherein the rotational power of the engine is steplessly shifted. A continuously variable transmission is provided, and when the behavior is controlled by the brake, the control means controls the speed ratio of the continuously variable transmission to the upshift side or increases the operating oil pressure supplied to the continuously variable transmission, and then controls the brake. A behavior control device for an automobile that starts behavior control by a vehicle. 29. A vehicle behavior control device comprising a control means for estimating a running state of a vehicle and controlling a yaw rate behavior of the vehicle based on the estimation result, wherein a rotational power of an engine is steplessly shifted. A vehicle behavior control device provided with a continuously variable transmission, wherein the control means controls the continuously variable transmission to an upshift side when an oversteer state of the vehicle is detected.