JP3993929B2 - Vehicle slip control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a vehicle slip control device that controls the slip state of front, rear, left, and right wheels of a vehicle and controls the behavior of the vehicle to improve steering stability. It belongs to the field of fail-safe technology.
[0002]
[Prior art]
  Conventionally, as a slip control device for this type of vehicle, for example, as disclosed in Japanese Patent Laid-Open No. 6-87421, the braking force applied to the left and right wheels of the vehicle is distributed to different magnitudes around the center of gravity of the vehicle body. It is known that a yaw moment is generated so that the yaw rate of the vehicle coincides with a control target value to improve the steering stability of the vehicle during braking. In this device, the running state including the posture state of the vehicle is detected by various sensors, and if the disconnection or short circuit of the sensor or the failure of the control device itself occurs, the control becomes impossible. When such a failure is detected, behavior control is prohibited. At that time, if the control is being executed, the braking force of each wheel under control is gradually changed to an uncontrolled state, and the behavior control is stopped while preventing a change in the behavior of the vehicle due to a sudden change in the yaw rate. Like to do.
[0003]
  Japanese Patent Laid-Open No. 9-109855 discloses an alternative that does not depend on a detection value obtained by an abnormal wheel speed sensor before stopping the control if behavior control is being executed when an abnormality occurs in the wheel speed sensor. The behavior control of the vehicle is performed only for a predetermined time, so that the behavior change of the vehicle due to the suspension of the control is prevented.
[0004]
[Problems to be solved by the invention]
  By the way, for example, a lateral acceleration sensor that detects a lateral acceleration acting on a vehicle, a yaw rate sensor that detects a yaw rate, and the like accurately detect whether the detected value is normal until the vehicle is in a predetermined traveling state such as a turning state. Failure determination cannot be performed. For this reason, in the above conventional slip control device, even if the lateral acceleration sensor, the yaw rate sensor or the like is broken until the vehicle turns, etc., the failure cannot be detected. Therefore, based on the output signal from the broken sensor. Incorrect behavior control may occur. In this case, since the vehicle exhibits a behavior unrelated to the driving operation and will of the driver, not only does the driver feel a very uncomfortable feeling, but also the vehicle is caused by the erroneous behavior control described above. There is also a possibility that the turning posture of this will collapse.
[0005]
  The present invention has been made in view of such a point, and the object of the present invention is to devise a control procedure until the failure determination of all the sensors is completed, even if the sensor has failed. The purpose is to prevent erroneous behavior control and to ensure the stability of the vehicle during the operation.
[0006]
[Means for Solving the Problems]
  In order to achieve the above object, according to the solution means of the present invention, the vehicle behavior control based on the output signal from the detection means until the vehicle enters a predetermined traveling state and the failure determination of the detection means is completed. And the steering stability of the vehicle is ensured by slip control of each wheel.
[0007]
  Specifically, in the first aspect of the invention, the first control means for controlling the value relating to the slip of each wheel to a predetermined value or less based on the output signal from the wheel speed sensor for detecting the wheel speed of each wheel of the vehicle. And the vehicleRunningRow state quantityAt least turningA vehicle slip control device including second control means for controlling the behavior of the vehicle based on an output signal from a detection means for detecting a state quantity is an object. And the failure determination means which determines the failure of the said detection means,From the start of vehicle travelControl correction means that suppresses control by the second control means while performing control by the first control means until failure determination by the failure determination means is completed is provided.
[0008]
  here,The turning state quantity is at least the turning state quantity.Changes according to the turning state of the vehicleBecause thingsBecauseBesides thisRunning state quantity that does not change immediately after the vehicle starts runningMeans that. Moreover, what is necessary is just to let the value regarding the slip of a wheel be a wheel slip ratio or a wheel slip amount, for example.
[0009]
  According to the above configuration, the output value from the detection unit does not change from when the vehicle starts to run to a predetermined running state such as a turning state, and the failure determination of the detection unit by the failure determination unit ends. In the meantime, the behavior control of the vehicle by the second control means is suppressed during that time. As a result, even if the detection means has failed, it is possible to suppress erroneous behavior control by the second control means until the failure determination is completed, so that the driver feels uncomfortable, The collapse of the turning posture of the vehicle due to erroneous control can be prevented.
[0010]
  Further, even if the vehicle behavior control by the second control means is suppressed as described above, the slip state of each wheel is controlled to a predetermined value or less by the first control means to prevent the locked state or idling state of each wheel. Therefore, the driving stability of the vehicle can be ensured. At that time, the determination of the failure of the wheel speed sensor ends immediately after the vehicle starts running, so that erroneous wheel slip control by the first control means is not performed due to the failure of the wheel speed sensor.
[0011]
  In the second aspect of the invention, the control correction means in the first aspect of the invention is configured to increase the sensitivity of the wheel slip control by the first control means until the failure judgment of the detection means by the failure judgment means is completed. . By this, the control sensitivity by the first control means is increased and the slip amount of each wheel is controlled to be extremely small, so that the locked state and the idling state of each wheel can be reliably prevented and the steering stability of the vehicle can be improved. In addition, since the behavior of the vehicle is stable and the behavior control of the vehicle by the second control means is not performed, erroneous behavior control by the second control means is reliably prevented.
[0012]
  In the invention according to claim 3, the control correction means in the invention according to claim 2 reduces the control start threshold value of the first control means until the failure judgment of the detection means by the failure judgment means is completed. . Thus, by reducing the control start threshold value of the first control means, the control is started earlier while the slip amount of the wheel is small, and the frequency of control is increased, thereby increasing the control sensitivity. Can do.
[0013]
  In the invention according to claim 4, the control correction means in the invention according to claim 2 increases the control gain of the first control means until the failure determination of the detection means by the failure determination means is completed. Thus, by increasing the control gain of the first control means, it is possible to increase the control sensitivity and increase the control sensitivity.
[0014]
  According to a fifth aspect of the present invention, the control correction means according to the second or fourth aspect of the invention is such that when the failure determination of the detection means by the failure determination means is completed and the wheel slip control by the first control means is being executed. The control sensitivity is continuously increased until the wheel slip control is completed.
[0015]
  Thus, when the failure determination of the detection means by the failure determination means is completed, if the wheel slip control by the first control means is being executed, the increase in control sensitivity is continued until the end of the control. Simultaneously with the end of the vehicle, it is possible to prevent the control amount of the wheel slip control by the first control means from changing suddenly and to stabilize the behavior of the vehicle.
[0016]
  It should be noted that to continue increasing the control sensitivity by the first control means, the increased control sensitivity may be retained, or the increased control sensitivity may be gradually decreased.
[0017]
  According to a sixth aspect of the present invention, the detection means in the first aspect of the invention includes a lateral acceleration sensor that detects the lateral acceleration of the vehicle, a yaw rate sensor that detects the yaw rate of the vehicle, a steering angle sensor that detects the steering angle, or a master. It is assumed that at least one master cylinder pressure sensor for detecting the brake pressure in the cylinder is included.
[0018]
  That is, the lateral acceleration sensor, the yaw rate sensor, and the rudder angle sensor all have constant output values that are substantially zero until the vehicle is turned, and cannot be determined as malfunctioning. Further, the master cylinder pressure sensor does not change the output value until the vehicle is decelerated after the brake operation by the driver is performed, and the failure determination cannot be performed. In this way, the configuration of the detection means is embodied, and by suppressing the behavior control of the vehicle by the second control means until the failure determination of each of these sensors is completed, the second control means immediately after the vehicle travels. It is possible to prevent erroneous behavior control.
[0019]
  According to the seventh aspect of the invention, the same effect as that of the second aspect of the invention can be obtained.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(overall structure)
  FIG. 1 shows a vehicle to which a vehicle slip control apparatus according to an embodiment of the present invention is applied. Reference numeral 1 denotes a vehicle body, 2, 2,... Individually to four wheels 21FR, 21FL, 21RR, and 21RL on the front, rear, left, and right. Four hydraulic brakes arranged, 3 is a pressure unit for supplying pressure fluid to each brake 2, and 4 is a hydraulic pressure for distributing and supplying pressure fluid from the pressure unit 3 to each brake 2. It is a unit (Hudraulic Unit: hereinafter referred to as HU). Further, 5 is a main controller for controlling the slip state of each wheel and the behavior of the vehicle, 6 is an electromagnetic pickup type wheel speed sensor for detecting the wheel speed of each wheel 21, and 7 is the left and right acting on the vehicle. A lateral acceleration sensor for detecting the lateral acceleration Gy in the direction, a yaw rate sensor 8 for detecting the yaw rate ψ ′ acting on the vehicle, and a steering angle sensor 9 for detecting the steering angle θH of the steering wheel. The wheel speed sensors 6, 6,..., The lateral acceleration sensor 7, the yaw rate sensor 8, the rudder angle sensor 9, and a hydraulic pressure sensor 33 described later constitute detection means.
[0021]
  Further, 10 is a master cylinder that generates brake fluid pressure (master cylinder pressure) according to the driver's brake operation, and 11 is an engine having a plurality of cylinders. Although not shown, a throttle valve driven by an actuator is provided in the intake passage of the engine 11, and an injector is provided for each cylinder of the engine 11 in the intake passage downstream of the throttle valve. The engine output is controlled by opening control and injector operation control. Reference numeral 12 denotes an automatic transmission (AT) that shifts the output rotation of the engine 11 and transmits it to the drive wheel side via a drive shaft (not shown). Reference numeral 13 denotes an opening control of the throttle valve according to the accelerator operation by the driver. The EGI controller controls the operating state of the engine 11 by controlling the operation of the injector and the ignition timing.
[0022]
  The vehicle is provided with a longitudinal acceleration sensor (not shown) that detects acceleration acting in the longitudinal direction.
[0023]
  As shown in FIG. 2, the brake 2 of the right front wheel 21FR and the brake 2 of the left rear wheel 21RL are connected to the master cylinder 10 by a first hydraulic line 22a, while the brake 2 of the left front wheel 21FL and the right rear wheel are connected. The brake 2 of the wheel 21RR is connected to the master cylinder 10 by a second hydraulic line 22b different from the first hydraulic line 22a, so that two independent brake systems of so-called X piping type are configured. ing. In addition, a braking force is applied to each of the wheels 21FR, 21FL,... According to the depression of the brake pedal 14 by the driver.
[0024]
  The pressurizing unit 3 is configured so that the hydraulic pumps 31a and 31b connected to the first and second hydraulic lines 22a and 22b, respectively, and the hydraulic pumps 31a and 31b and the master cylinder 10 can be intermittently connected. Cut valves 32a and 32b disposed in the first and second hydraulic pressure lines 22a and 22b, respectively, and a hydraulic pressure sensor (master cylinder pressure) for detecting the hydraulic pressure on the master cylinder 10 side relative to the cut valves 32a and 32b. Sensor) 33. Then, the cut valves 32a and 32b are closed in accordance with a signal from the SCS controller 5, so that the hydraulic fluid discharged from the hydraulic pumps 31a and 31b is HU4 regardless of the brake operation by the driver. Are supplied to the brakes 2, 2,.
[0025]
  The HU 4 individually supplies the pressure fluid supplied from the pressurizing unit 3 to the wheel cylinders (not shown) of each brake 2 via the first hydraulic pressure line 22a or the second hydraulic pressure line 22b. .. Are provided with pressure increasing valves 41, 41... For connecting the brakes 2 to the reservoir tank 42, and pressure reducing valves 43, 43. .. And the pressure reducing valves 43, 43,... Are independently controlled to increase or decrease in response to a signal from the SCS controller 5, so that the brakes 2, 2,. The wheel cylinder pressure is increased or decreased to control the braking force applied to each wheel 21FR, 21FL,.
[0026]
  As shown in FIG. 3, the main controller 5 includes a first CPU (Central Processing Unit) 5a as first control means for performing well-known ABS (Anti-Skid Brake System) control and TCS (Traction Control System) control. It has. In the ABS control, when the locking tendency of the wheels 21FR, 21FL,... Increases, the hydraulic pressure supplied to the brakes 2 is reduced to prevent the brake lock. When the tendency of idling of the left and right front wheels 21FR and 21FL, which are driving wheels, is strengthened, idling is prevented by suppressing the driving force of the left and right front wheels 21FR and 21FL.
[0027]
  The main controller 5 is provided with a second CPU 5b as second control means for performing SCS (Stability Control System) control, which will be described in detail later. At the same time, the yaw moment is applied to the vehicle by controlling the braking force for each wheel, and the engine output is decreased to control the behavior of the vehicle so that the turning posture converges toward the target travel direction.
[0028]
  Further, the main controller 5 determines failure such as abnormal output of the wheel speed sensors 6, 6,..., Lateral acceleration sensor 7, yaw rate sensor 8, rudder angle sensor 9, hydraulic pressure sensor 33, and longitudinal acceleration sensor. The control sensitivity of the ABS control and the TCS control by the first CPU 5a is increased and the SCS control by the second CPU 5b is suppressed until the failure determination of each sensor by the failure determination unit 5c and the failure determination unit 5c is completed. And a control correction unit 5d.
(Basic control)
  First, the basic control procedure by the main controller 5 will be described with reference to the flowchart shown in FIG. In this basic control, when the driver gets into the vehicle and turns on the ignition key, the main controller 5 and EGI controller 13 are initialized in step SA1 to clear the calculation values stored in the previous processing. To do. In the next step SA2, after the origin correction of the wheel speed sensors 6, 6,... Is performed, signal inputs to the main controller 5 are received from these sensors. In step SA3, based on these input signals, common vehicle state quantities such as the vehicle body speed, the vehicle body deceleration, and the vehicle body speed at each wheel position are calculated.
[0029]
  Subsequently, in steps SA4, SA5, and SA6, as will be described in detail later, control computation for SCS control, control computation for ABS control, and control computation for TCS control are performed, and then each computation of these three controls is performed in step SA7. The result is arbitrated by a predetermined method, and the control output amount to the pressurizing unit 3, the HU 4 and the EGI controller 13 is determined. In step SA8, control is output to the pressurizing unit 3 or the like to apply the required braking force to the wheels 21FR, 21FL,... And to stabilize the behavior by deceleration of the vehicle. After the output of the engine 11 is reduced and the fail-safe determination and processing are performed in step SA9, the process returns.
(SCS control)
  Next, details of the SCS control will be described with reference to FIGS.
[0030]
  In step SB2 of the flowchart shown in FIG. 5, the wheel speed v1 of the wheel 21FR, the wheel speed v2 of the wheel 21FL, the wheel speed v3 of the wheel 21RR, the wheel speed v4 of the wheel 21RL, the lateral acceleration Gy of the vehicle, and the yaw rate ψ ′ of the vehicle. And each input of the steering angle θH of the steering. In step SB4, the vehicle body speed Vscs is calculated based on the wheel speeds v1, v2,..., And in step SB6, the vertical weight of each wheel is calculated based on the wheel speeds v1, v2,. . In step SB8, the vehicle body side slip angle β is calculated based on the vehicle body speed Vscs, the wheel speeds v1, v2,..., The lateral acceleration Gy, the yaw rate ψ ′, and the steering angle θH.
[0031]
  In step SB10 following step SB8, the slip rate s1 of the wheel 21FR and the slip rate s2 of the wheel 21FL based on the wheel speeds v1, v2,..., The vehicle body speed Vscs, the vehicle body side slip angle β, the yaw rate ψ ′, and the steering angle θH. The slip rate s3 of the wheel 21RR, the slip rate s4 of the wheel 21RL, and the slip angle of each wheel are calculated. Subsequently, in step SB12, all the grips that the tires 23, 23,... Can exert on the wheels 21FR, 21FL,... On the basis of the vertical load of each wheel, the slip rates s1, s2,. Calculate the wheel load factor, which is the ratio of the current grip force to the force. In step SB14, the road surface friction coefficient μscs is calculated based on the wheel load factor and the lateral acceleration Gy. In step SB16, the target yaw rate ψ′TR and the target yaw rate ψ′TR are calculated based on the road surface friction coefficient μscs, the vehicle body speed Vscs, and the steering angle θH. The target side slip angle βTR is calculated.
[0032]
  Note that the calculations in the above steps SB4 to SB16 are each performed by the second CPU 5b based on a well-known mathematical method.
[0033]
  Subsequently, in step SB18 of the flowchart shown in FIG. 6, the yaw rate deviation amount (| ψ′TR−ψ ′ |) between the yaw rate ψ ′ and the target yaw rate ψ′TR, the vehicle body side slip angle β and the target side slip angle. The side slip angle deviation amount (| βTR−β |) with βTR is compared with intervention determination threshold values Δψ′ST and ΔβST1 set in advance for intervention determination of yaw rate control described later. The yaw rate deviation amount (| ψ′TR−ψ ′ |) is greater than or equal to the intervention determination threshold value Δψ′ST, or the skid angle deviation amount (| βTR−β |) is the intervention determination threshold value ΔβST1. In the above case, the deviation of the turning posture of the vehicle with respect to the target traveling direction is increasing, and it is determined that SCS control intervention is necessary, and the process proceeds to Step SB20. On the other hand, when the yaw rate deviation amount is smaller than the intervention determination threshold value Δψ′ST and the skid angle deviation amount is smaller than the intervention determination threshold value ΔβST1, no SCS control intervention is required. And return.
[0034]
  In the following step SB20, the side slip angle deviation amount (| βTR−β |) is compared with a switching judgment threshold value ΔβST2 (ΔβST2> ΔβST1) set in advance for judgment of switching to the side slip angle control described later. If the side slip angle deviation amount (| βTR−β |) is smaller than the switching determination threshold value ΔβST2, the process proceeds to step SB22 to set the target yaw rate ψ′TR as the SCS control target value, and then to step Proceeding to SB24, the SCS control amount ψ'amt is calculated by multiplying the yaw rate deviation amount (| ψ'TR-ψ '|) by a preset control gain G1.
[0035]
                  ψ′amt = G1 × | ψ′TR−ψ ′ |
  That is, while it is determined that the change in the turning posture of the vehicle is relatively small and stable, the yaw rate deviation is adjusted so that the yaw rate ψ ′ of the vehicle converges to the target yaw rate ψ′TR corresponding to the driving operation of the driver. Yaw rate control that smoothly changes the behavior of the vehicle to follow the driving operation of the driver by applying a relatively small yaw moment proportional to the amount (| ψ′TR−ψ ′ |) to the vehicle. To do.
[0036]
  On the other hand, if the slip angle deviation amount (| βTR−β |) is equal to or larger than the switching determination threshold value ΔβST2 in step SB20, the process proceeds to step SB26, and after setting the target skid angle βTR as the SCS control target value, Proceeding to step SB28, the SCS control amount βamt is calculated by multiplying the skid angle deviation amount (| βTR-β |) by a preset control gain G2.
[0037]
                  βamt = G2 × | βTR-β |
  That is, when it is determined that the turning posture of the vehicle is about to collapse, a relatively large yaw proportional to the side slip angle deviation amount (| βTR−β |) is set so that the vehicle body side slip angle β converges to the target side slip angle βTR. By causing the moment to act on the vehicle, side slip angle control is performed to quickly correct the turning posture of the vehicle.
[0038]
  Then, in step SB30 following step SB24 or step SB28, fail safe determination and processing for each sensor, HU4, etc. are performed, and in subsequent step SB32, the calculation results of the SCS control, ABS control and TCS control are determined in a predetermined manner. Mediate by. The outline of this arbitration will be described. When ABS control is performed when trying to perform SCS control, by correcting the control amount of the ABS control based on the SCS control amount ψ′amt or βamt, SCS control is performed while giving priority to ABS control. When TCS control is performed when trying to perform SCS control, the operation of the pressurizing unit 3 and the HU 4 for the TCS control is stopped and only control for lowering the output torque of the engine 11 is performed. In this way, SCS control is executed.
[0039]
  Subsequently, in step SB34, wheels 21FR, 21FL,... To which a braking force is applied for SCS control are selected based on the SCS control amount ψ′amt or βamt, and these selected wheels 21FR, 21FL,. The amount of braking force applied to each is calculated. The outline of the selection of the wheels and the calculation of the braking force amount are as follows. When the yaw rate ψ ′ of the vehicle is increased clockwise in the yaw rate control, and when the turning posture of the vehicle is corrected to the right side in the side slip angle control. Applies a braking force corresponding to the SCS control amount ψ′amt or βamt to the right front wheel 21FR or the right front and rear wheels 21FR, 21RR, and causes a clockwise yaw moment to act on the vehicle. On the contrary, when the yaw rate ψ ′ of the vehicle is increased counterclockwise and when the turning posture of the vehicle is to be corrected to the left side, the SCS control is performed on the left front wheel 21FL or the left front and rear wheels 21FL, 21RL. A braking force corresponding to the amount ψ′amt or βamt is applied, and a counterclockwise yaw moment is applied to the vehicle.
[0040]
  Then, in step SB36 following step SB34, a brake control amount (wheel cylinder pressure) to each brake 2 for applying a required braking force to the wheels 21FR, 21FL,... Selected in step SB34 is calculated. Further, the valve opening degree of each of the pressurizing valves 41, 41,... And the pressure reducing valves 43, 43,.
[0041]
  In the subsequent step SB38, an engine control amount corresponding to a decrease amount of the engine output necessary for stabilizing the behavior due to deceleration of the vehicle is calculated. That is, in the control of the output torque reduction of the engine 11, the EGI controller 13 operates the throttle valve actuator to throttle the throttle valve opening regardless of the driver's accelerator operation, and performs fuel cut or cylinder cut. The output torque of the engine 11 is reduced. The fuel cut is to stop the fuel injection of all cylinders of the engine 11 instantaneously, and the cylinder cut is to stop the fuel injection of several cylinders similarly.
[0042]
  In step SB40, control output is performed to the pressurizing unit 3, HU4 and EGI controller 13 based on the calculation results in step SB36 and step 38, SCS control is executed, and then the process returns.
[0043]
  In this way, yaw moment is applied around the center of gravity of the vehicle by SCS brake control that applies braking force independently to the front, rear, left, and right wheels 21FR, 21FL,... And the output of the engine 11 is reduced by a predetermined amount. The vehicle speed is lowered by SCS torque down control to improve the steering stability of the vehicle.
(ABS control)
  Next, the details of the ABS control will be described based on the flowchart shown in FIG. 7. In step SC1, whether or not the driver has operated the brake based on an output signal from a brake on / off sensor (not shown) attached to the brake pedal 14. If NO is determined that the brake operation is not performed, the process proceeds to step SC2, and the value of the brake flag Fbrake indicating the presence or absence of the brake operation by the driver is set to Fbrake = 0, and the process returns. On the other hand, if it is determined YES that the brake operation has been performed, the process proceeds to step SC3, where the road surface friction coefficient μABS estimated from the wheel speeds v1, v2,..., The vehicle body speed and the master cylinder pressure of each wheel 21FR, 21FL,. , The target slip ratio sTR, which is the control target value of the wheel slip ratios s1, s2,..., And the ABS control start threshold value sST are calculated.
[0044]
  Subsequently, in step SC4, the start threshold value sST is corrected in accordance with a value of a control correction flag Fcor described later. That is, while the failure determination of each sensor is not completed (Fcor = 1), the value of the start threshold value sST is corrected to be small, and the ABS control is started while the wheel slip ratios s1, s2,. To be.
[0045]
  Control after step SC5 is performed individually for each wheel 21FR, 21FL,. That is, first, in step SC5, the wheel slip rates s1, s2,... Of each wheel are individually compared with the start threshold value sST, and if the wheel slip rates s1, s2,. If the wheel slip ratios s1, s2,... Are larger than the start threshold value sST, the process proceeds to step SC7, the brake flag Fbrake = 1 is set, and the process proceeds to step SC8. In step SC6, the value of the brake flag Fbrake is determined. If Fbrake = 1 and the brake operation is YES, the process proceeds to step SC8. On the other hand, if Fbrake = 0 and the brake operation is not in progress, the process returns. That is, once started, the ABS control is continued until the brake operation of the driver is stopped or the wheel slip ratios s1, s2,... Of each wheel reach the target slip ratio sTR.
[0046]
  Subsequently, in steps SC8 and SC9, a brake control amount B (wheel cylinder pressure) for controlling the braking force to each wheel 21FR, 21FL,. That is, in step SC8, the base control amount Bbase is determined by the amount of deviation between the wheel slip ratios s1, s2,... And the target slip ratio sTR of each wheel 21FR, 21FL, ... and the wheel slip ratios s1, s2,. Read from the map according to the amount of change. This map is electronically stored in the memory of the main controller 5, and the larger the deviation between the wheel slip rates s1, s2,... And the target slip rate sTR of each wheel 21FR, 21FL,. , And the wheel cylinder pressure decreases as the decrease in the wheel slip ratio s1, s2,... Increases, while the wheel cylinder pressure increases as the increase in the wheel slip ratio s1, s2,. Is set to be large.
[0047]
  In the following step SC9, the brake control amount B is calculated by multiplying the base control amount Bbase by a preset control gain k1. At this time, as in step SC4, the control gain k1 is corrected in accordance with the value of a control correction flag Fcor described later. That is, if the failure determination of each sensor has not been completed (Fcor = 1), the control gain k1 is greatly corrected to increase the brake control amount B, thereby improving the ABS control response.
[0048]
  Finally, in step SC10, control output to the HU 4 is executed based on the calculated brake control amount B, and the pressurizing valves 41, 41,... And the decompression valves 43, 43,. The brake force applied to the wheels 21FR, 21FL,... Is controlled by increasing or decreasing the wheel cylinder pressure of the brakes 2, 2,. Thereby, the wheel slip ratios s1, s2,... Of the wheels 21FR, 21FL,... Are controlled so as to become the optimum target slip ratio sTR according to the road surface condition, and each wheel 21FR, 21FL,. A braking force is generated.
(TCS control)
  Next, the details of the TCS control will be described based on the flowchart shown in FIG. 8. In step SD1, it is determined whether or not the throttle valve of the engine 11 is opened by the accelerator operation by the driver, and the throttle valve is opened. If it is determined that the state is not NO, the process proceeds to step SD2, and the value of the accelerator flag Facc indicating the presence or absence of the accelerator operation by the driver is set to Facc = 0, and the process returns. On the other hand, if it is determined YES that the accelerator operation is performed, the process proceeds to step SD3, and the road surface friction coefficient μTCS estimated from the wheel speeds v1, v2 of the left and right front wheels 21FR, 21FL, which are drive wheels, the vehicle body speed, and the engine output. , The target slip ratio sTR, which is the control target value of the wheel slip ratios s1, s2,..., And the TCS control start threshold sST are calculated.
[0049]
  Subsequently, in step SD4, the start threshold value sST is corrected in accordance with the value of a control correction flag Fcor described later. That is, while the failure determination of each sensor is not completed (Fcor = 1), the value of the start threshold value sST is corrected to be small, and the TCS control is started while the wheel slip ratios s1, s2,. To be.
[0050]
  In step SD5, the wheel slip rates s1, s2 of the left and right front wheels 21FR, 21FL are individually compared with the start threshold value sST, and if both the wheel slip rates s1, s2 are NO below the start threshold value sST. On the other hand, if either of the wheel slip ratios s1 and s2 is larger than the start threshold value sST, the process proceeds to step SD6, the process proceeds to step SD7, the accelerator flag Facc = 1 is set, and the process proceeds to step SD8. In step SD6, the value of the accelerator flag Facc is determined. If Facc = 1 and the accelerator is being operated, the process proceeds to step SD8, while if Facc = 0 and the accelerator is not being operated, the process returns. That is, the TCS control is continued until the driver's accelerator operation is stopped or the wheel slip ratios s1 and s2 of the left and right front wheels 21FR and 21FL reach the target slip ratio sTR once started, as in the ABS control.
[0051]
  Subsequently, in steps SD8, SD9, and SD10, a brake control amount B (wheel cylinder pressure) for controlling the driving force to the left and right front wheels 21FR and 21FL, and a control amount for lowering the output torque of the engine 11, that is, an engine control amount. E is calculated. That is, at step SD8, the base control amount Bbase of the brake control amount B is set to the deviation amount between the wheel slip ratios s1, s2 and the target slip ratio sTR for each of the left and right front wheels 21FR, 21FL, and the wheel slip ratio s1. , S2,... Are read from the map according to the amount of change. This map is electronically stored in the memory of the main controller 5 so that the wheel cylinder pressure increases as the deviation between the wheel slip rates s1, s2 and the target slip rate sTR increases. The wheel cylinder pressure decreases as the decrease change amount of the slip ratios s1, s2,... Increases, while the wheel cylinder pressure increases as the increase change amount of the wheel slip ratios s1, s2,.
[0052]
  In subsequent step SD9, as in step SD8, a base control amount Ebase of the engine control amount E by the EGI controller 13 is obtained. The engine base control amount Ebase is read from a map stored in the memory of the main controller 5 in the same manner as the base control amount Bbase of the brake control amount B. In this map, the wheel slip ratios s1, s2 and the target slip are determined. The larger the deviation from the rate sTR, the larger the amount of decrease in the output torque, and the larger the amount of change in the wheel slip ratios s1, s2,. It is set so that the amount of decrease in the output torque increases as the increase in the rate s1, s2,.
[0053]
  In step SD10, the brake control amount B and engine control amount E are multiplied by the brake base control amount Bbase and engine base control amount Ebase obtained in SD8 and SD9, respectively, by preset control gains k1 and k2. Calculate. At this time, similarly to step SD4, the control gains k1 and k2 are corrected in accordance with the value of a control correction flag Fcor described later. That is, if the failure determination of each sensor is not completed (Fcor = 1), the control gains k1 and k2 are largely corrected to increase the brake control amount B and the engine control amount E, thereby responding to the TCS control. Try to increase sex.
[0054]
  Finally, in step SD11, based on the calculated brake control amount B, control output to the pressurization unit 3, HU4 and EGI controller 13 is executed, and pressurization valves attached to the left and right front wheels 21FR, 21FL. 41 and 41 and the pressure reducing valves 43 and 43 are opened and closed to increase or decrease the wheel cylinder pressures of the brakes 2 and 2, thereby controlling the braking forces of the left and right front wheels 21FR and 21FL, respectively. At the same time, the EGI controller 13 operates the throttle valve actuator based on the calculated engine control amount E to reduce the throttle valve opening, and the fuel or cylinder is cut to reduce the output torque of the engine 11. Thereby, the driving force to the left and right front wheels 21FR and 21FL is controlled, and the front wheels 21FR and 21FL generate the maximum driving force.
(Failure judgment of each sensor)
  Next, as characteristic portions of the present invention, sensor systems in fail-safe determination and processing, that is, wheel speed sensors 6, 6,..., Lateral acceleration sensor 7, yaw rate sensor 8, rudder angle sensor 9, hydraulic pressure sensor 33, longitudinal acceleration Details of the failure determination by the sensor failure determination unit 5c will be described based on FIG. 9, FIG. 10, and FIG.
[0055]
  In step SE1 of the flowchart shown in FIG. 9, first, failure determination of the wheel speed sensors 6, 6,. This is because the vehicle speed Vscs is equal to or higher than a predetermined value, but the wheel speeds v1, v2,... Of one or two of the four wheels 21FR, 21FL,. If the vehicle speed Vscs is lower than the vehicle speed Vscs, the wheel speed sensors 6, 6,... Of the specific wheels 21FR, 21FL,. Therefore, since the determination result is fixed immediately after the vehicle starts, it is considered that the failure determination is always completed before the above-described SCS control or ABS control is started. If it is determined in step SE1 that the wheel speed sensors 6, 6,... Are not broken, the process proceeds to step SE2 to store the normality of the wheel speed sensors 6, 6,. If it is determined YES, the process proceeds to step SE3, and the abnormality confirmation of the wheel speed sensors 6, 6,.
[0056]
  Subsequently, in step SE4, a deceleration state of the vehicle more than a predetermined value is determined from the rate of change of the wheel speeds v1, v2,. That is, when it is determined that the change rate of the wheel speeds v1, v2,... Of the wheels 21FR, 21FL,... Is small and the driver does not perform the brake operation, the process proceeds to step SF1 of the flowchart shown in FIG. On the other hand, when the wheel speeds v1, v2,... Of the wheels 21FR, 21FL,... Are rapidly decreasing and it is determined YES that the vehicle is in a predetermined deceleration state by the driver's brake operation, step SE5 is entered. move on.
[0057]
  In step SE5, it is determined whether or not the longitudinal acceleration detected by the longitudinal acceleration sensor is a value within a predetermined range estimated from the rate of change of the wheel speeds v1, v2,. That is, it is determined whether or not the longitudinal acceleration sensor acting on the vehicle has a large value corresponding to deceleration due to braking of the vehicle, and if the failure is determined to be within a predetermined range, the process proceeds to step SE6. The process proceeds to store the normal determination of the longitudinal acceleration sensor in the memory. On the other hand, if NO is determined not to fall within the predetermined range, the process proceeds to step SE7 to store the abnormality determination of the longitudinal acceleration sensor in the memory.
[0058]
  Subsequently, at step SE8, it is determined whether or not the brake hydraulic pressure of the master cylinder 10 detected by the hydraulic pressure sensor 33 is a value within a predetermined range estimated from the rate of change of the wheel speeds v1, v2,. judge. That is, the failure determination of the hydraulic pressure sensor 33 is performed based on whether or not the hydraulic pressure generated in the master cylinder 10 is a large value corresponding to deceleration due to vehicle braking. The process proceeds to SE9 and the normality of the hydraulic pressure sensor 33 is stored in the memory. On the other hand, if NO is determined to be not within the predetermined range, the process proceeds to step SE10 and the abnormal determination of the hydraulic pressure sensor 33 is stored in the memory.
[0059]
  Subsequent to the flow of FIG. 9, in step SF1 of the flowchart shown in FIG. 10, the deviation amounts (| v3−v4 |) of the wheel speeds v3 and v4 of the left and right rear wheels 21RR and 21RL which are driven wheels are previously determined. It is determined whether or not the set value is equal to or greater than the predetermined value, and if the deviation is smaller than the predetermined value, it is determined that the vehicle is in a substantially straight traveling state, the process proceeds to step SF2, and the value of the control correction flag Fcor is determined. Is set to Fcor = 1, and then the process returns. When the control correction flag Fcor = 1, the control intervention determination threshold values Δψ′ST, ΔβST1 and the switching determination threshold value ΔβST2 in the SCS control described above are greatly corrected by a predetermined ratio, and the SCS control is performed. Intervention is suppressed. At the same time, when the control correction flag Fcor = 1, as described above, in the ABS control and the TCS control, the control start threshold value sST is corrected to be small, and the control gains k1 and k2 are largely corrected. The control sensitivity of the ABS control and the TCS control is increased.
[0060]
  On the other hand, if the left and right wheel speed deviation amount (| v3 -v4 |) is YES at a predetermined value or more in step SF1, it is determined that the vehicle is turning more than a predetermined value, and the process proceeds to step SF3. . In this step SF3, it is determined whether or not the detection value (steering angle) θH by the steering angle sensor 9 is a value within a predetermined range estimated from the wheel speed deviation amount (| v3−v4 |). That is, the following relational expression is established between the wheel speed deviation amount (| v3−v4 |) of the left and right rear wheels 21RR and 21RL and the steering angle θH, where R is the turning radius of the vehicle.
[0061]
    1 / R = | v3−v4 | × m1 (Formula 1)
        R = WB / tan (θH / m @ 2) + TD / 2 (Expression 2)
        However,
              WB: Vehicle wheelbase
              TD: Vehicle rear wheel tread
        m1, m2: Constants determined by vehicle specifications such as steering mechanism
  If the detected value θH detected by the rudder angle sensor 9 is NO that is not within the predetermined range, the process proceeds to step SF11 and the abnormality determination of the rudder angle sensor 9 is stored in the memory, while the detected value is within the predetermined range. If the value is YES, the process proceeds to step SF4 and the normality of the steering angle sensor 9 is stored in the memory.
[0062]
  Subsequently, in step SF5, it is determined whether or not the detected value (yaw rate) ψ ′ by the yaw rate sensor 8 is a value within a predetermined range estimated from the detected value θH of the steering angle sensor 9 and the vehicle body speed Vscs. If YES in the predetermined range, the process proceeds to step SF6 and the normality of the yaw rate sensor 8 is stored in the memory. On the other hand, if NO is determined not in the predetermined range, the process proceeds to step SF7 and the abnormality of the yaw rate sensor 8 is confirmed. Is stored in the memory.
[0063]
  Subsequently, in step SF8, the detection value (lateral acceleration) Gy detected by the lateral acceleration sensor 7 is estimated from the detection value θH of the steering angle sensor 9 and the vehicle body speed Vscs, as in the case of the failure determination of the yaw rate sensor 8 in step SF5. If the value is within the predetermined range, if it is YES within the predetermined range, the normality confirmation is stored in the memory at step SF9, while if it is not within the predetermined range, the abnormality is confirmed at step SF10. Then, the process proceeds to step SG10 in the flowchart shown in FIG.
[0064]
  That is, if the rudder angle sensor 9 is normally determined, failure determination of the yaw rate sensor 8 and the lateral acceleration sensor 7 is performed based on the detection value θH by the rudder angle sensor 9 as in the flow of steps SF5 to SF10 described above. Yes.
[0065]
  On the other hand, after it is determined in step SF3 that the steering angle sensor 9 has failed and the abnormality confirmation is stored in the memory in step SF11, in step SF12, the turning radius of the vehicle is calculated based on the above (formula 1). R is calculated, and in the subsequent step SF13, the lateral acceleration acting on the vehicle is estimated and calculated based on the calculated turning radius R and the vehicle body speed Vscs. In step SF14, it is determined whether or not the detection value Gy detected by the lateral acceleration sensor 7 is a value within a predetermined range near the estimated lateral acceleration calculation value. If YES in the predetermined range, the process proceeds to step SF15, and the normality of the lateral acceleration sensor 7 is stored in the memory. Thereafter, the process proceeds to step SG1 in the flowchart shown in FIG. In step SF16, the abnormality confirmation is stored in the memory, and thereafter, the process proceeds to step SG5 of the flowchart shown in FIG.
[0066]
  In step SG1 of the flowchart shown in FIG. 11, the yaw rate acting on the vehicle is estimated and calculated based on the detection value Gy and the vehicle body speed Vscs detected by the lateral acceleration sensor 7.
[0067]
            Estimated value of yaw rate = Gy / Vscs−Vscs
  In the subsequent step SG2, it is determined whether or not the detected value ψ ′ detected by the yaw rate sensor 8 is a value within a predetermined range in the vicinity of the yaw rate estimated calculation value. If YES within the predetermined range, the process proceeds to step SG3. Thus, the normality determination of the yaw rate sensor 8 is stored in the memory, but if NO is not within the predetermined range, the process proceeds to step SG4, the abnormality determination of the yaw rate sensor 8 is stored in the memory, and then the process proceeds to step SG10.
[0068]
  In other words, if the rudder angle sensor 9 is determined to be abnormal and the lateral acceleration sensor 7 is determined to be normal, the yaw rate sensor is based on the detection value Gy detected by the lateral acceleration sensor 7 as in the flow of steps SG1 to SG4 described above. Eight failure determinations are made.
[0069]
  On the other hand, in step SG5 of FIG. 11 after it is determined that the lateral acceleration sensor 7 has failed in step SF13 of FIG. 10 and the abnormality confirmation is stored in the memory in step SF15, in step SG5 of FIG. And (Equation 2), the steering angle is estimated and calculated based on the left and right wheel speed deviation amounts (| v3 -v4 |). In the subsequent step SG6, the estimated steering angle value θHest and the vehicle body speed Vscs are calculated. The yaw rate is estimated and calculated.
[0070]
    Estimated value of yaw rate = θHest × Vscs × {(1−kVscs²) WB}
  In the subsequent step SG7, it is determined whether or not the detected value ψ 'detected by the yaw rate sensor 8 is a value within a predetermined range in the vicinity of the estimated yaw rate calculation value. If YES in the predetermined range, the process proceeds to step SG8. Thus, the normality determination of the yaw rate sensor 8 is stored in the memory, while if NO is not within the predetermined range, the process proceeds to step SG9, the abnormality determination of the yaw rate sensor 8 is stored in the memory, and then the process proceeds to step SG10.
[0071]
  That is, if both the rudder angle sensor 9 and the lateral acceleration sensor 7 are determined to be abnormal, the left and right wheel speed deviation amounts (|) determined based on the detected values v1, v2,. The failure determination of the yaw rate sensor 8 is performed on the basis of v3−v4 |).
[0072]
  Finally, in step SG10, memory is stored in steps SE6, SE7, SE9, SE10 in FIG. 9, steps SF4, SF6, SF7, SF9, SF10, SF15SF16 in FIG. 10, and steps SG3, SG4, SG8, SG9 in FIG. Whether or not all the sensors are normal is determined based on the failure determination result of each sensor stored in (1). If all the sensors are normally determined, the process proceeds to step SG11, the value of the control correction flag Fcor is set to Fcor = 0, and then the process returns. By setting the control correction flag Fcor = 0, the above-described intervention suppression of the SCS control is released, and normal SCS control that is not suppressed is executed based on output signals from all the normally operating sensors. The Further, the increase in the control sensitivity of the ABS control and the TCS control is continued until the end of the control, and this prevents the control amounts of the ABS control and the TCS control from changing suddenly at the same time as the end of the sensor failure determination.
[0073]
  In order to continue increasing the control sensitivity of the ABS control and the TCS control until the end of the control, the control gains k1 and k2 corrected to large values may be held as they are, or may be gradually decreased. May be.
[0074]
  On the other hand, in step SG10, if any sensor has failed and the abnormality has been determined, the process proceeds to step SG12, and a warning indicator lamp is displayed as a warning indicating that normal SCS control cannot be performed due to a sensor failure. Turn it on to alert the driver and then return. At this time, since the control correction flag Fcor is kept at 1, the above-described intervention suppression of the SCS control and increase in control sensitivity of the ABS control and the TCS control are continued until the ignition is turned off.
[0075]
  In addition to the wheel speed sensors 6, 6,..., The lateral acceleration sensor 7, the yaw rate sensor 8, the rudder angle sensor 9, the hydraulic pressure sensor 33, and the longitudinal acceleration sensor, only failure due to disconnection of the brake on / off sensor, etc. For what should be determined, failure determination is performed based on the presence or absence of pulse input to the main controller 5 at the same time as the ignition is turned on.
[0076]
  As described above, according to the vehicle slip control device of this embodiment, the lateral acceleration sensor 7, the yaw rate sensor 8, and the rudder until the vehicle is turned by a driver's steering operation for a while after the vehicle starts to travel. Although the output of the angle sensor 9 does not change and failure determination of these sensors cannot be performed, during that time, SCS control by the second CPU 5b is suppressed by the control correction unit 5d. Even if it is, it is possible to suppress erroneous execution of the SCS control based on the output signal from the sensor that has failed. As a result, it is possible to reduce a sense of incongruity felt by the driver due to incorrect SCS control, and to prevent the turning posture of the vehicle from collapsing due to the incorrect SCS control.
[0077]
  Further, the control correction unit 5d increases the control sensitivity of the ABS control and the TCS control until the failure determination of all the sensors by the failure determination means 5c is completed. It is possible to reliably prevent the wheels 21FR, 21FL,... From being locked or idling, thereby ensuring the vehicle handling stability even if the SCS control by the second CPU 5b is suppressed. Moreover, since the failure determination of the wheel speed sensors 6, 6,... Can be performed immediately after the vehicle starts running, erroneous ABS control or incorrect TCS control due to the failure of the wheel speed sensors 6, 6,. Is never done.
[0078]
  Further, the increase in the control sensitivity of the ABS control and the TCS control is continued until the end of the control even after the failure determination by the failure determination means 5c is completed. It is possible to prevent a sudden change in the behavior of the vehicle due to a sudden change in the control amount.
[0079]
  Note that the present invention is not limited to the above-described embodiment, but includes other various embodiments. That is, in the above embodiment, the first CPU 5a executes both the ABS control and the TCS control. However, only one of them may be executed.
[0080]
  Moreover, although 2nd CPU5b shall perform SCS control, it is good also as what controls not only this but a well-known rear-wheel steering apparatus, for example.
[0081]
  In the above embodiment, the SCS control intervention is suppressed until the failure determination of the sensor system is completed. However, the present invention is not limited to this. For example, the SCS control may be prohibited.
[0082]
  Furthermore, in the above embodiment, the SCS control is suppressed until the vehicle turns and the failure determination of the rudder angle sensor 9 and the like is completed. In addition to this, the driver's brake operation is performed. SCS control may be suppressed until the vehicle is decelerated.
[0083]
【The invention's effect】
  As described above, according to the slip control device for a vehicle according to the first aspect of the present invention, from the start of travel of the vehicle to the predetermined travel state until the failure determination of the detection means by the failure determination means ends. Since erroneous behavior control by the second control means is suppressed, even if the detection means is out of order, it is possible to reduce the driver's uncomfortable feeling due to erroneous behavior control, and to prevent erroneous control. It is possible to prevent the resulting turning posture of the vehicle from collapsing. In addition, the wheel slip control by the first control means can prevent the locked state and the idling state of each wheel and ensure the steering stability of the vehicle.
[0084]
  According to the second aspect of the present invention, the control sensitivity of the first control unit is increased until the failure determination of the detection unit by the failure determination unit is completed, so that the steering stability of the vehicle is improved and the second control unit is increased. It is possible to reliably prevent erroneous behavior control due to.
[0085]
  According to the third aspect of the invention, the control sensitivity can be increased by increasing the frequency of control by reducing the control start threshold value of the first control means.
[0086]
  According to the fourth aspect of the present invention, by increasing the control gain of the first control means, it is possible to increase the control sensitivity and increase the control sensitivity.
[0087]
  According to the fifth aspect of the present invention, it is possible to prevent the control amount from changing suddenly simultaneously with the end of the failure determination of the detection means by the failure determination means, and to suppress a change in the behavior of the vehicle.
[0088]
  According to the seventh aspect of the invention, the same effect as that of the second aspect of the invention can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a vehicle to which a slip control device of the present invention is applied.
FIG. 2 is a configuration diagram showing a hydraulic system of a brake.
FIG. 3 is a functional block diagram showing a configuration of a main controller.
FIG. 4 is a flowchart showing an outline of basic control.
FIG. 5 is a flowchart showing a control procedure in the first half of SCS control.
FIG. 6 is a flowchart showing a control procedure in the latter half of the SCS control.
FIG. 7 is a flowchart showing a procedure of ABS control.
FIG. 8 is a flowchart showing a procedure of TCS control.
FIG. 9 is a flowchart showing a control procedure for determining a failure of a wheel speed sensor, a longitudinal acceleration sensor, and a hydraulic pressure sensor.
FIG. 10 is a flowchart showing a control procedure in the first half of the failure determination of the steering angle sensor, the lateral acceleration sensor, and the yaw rate sensor.
FIG. 11 is a flowchart showing a control procedure in the latter half of the failure determination in FIG. 10;
[Explanation of symbols]
5a First CPU (first control means)
5b Second CPU (second control means)
5c Failure determination unit (failure determination means)
5d Control correction unit (control correction means)
6, 6, 6, 6 Wheel speed sensor
7 Lateral acceleration sensor
8 Yaw rate sensor
9 Rudder angle sensor
21FR, 21FL, 21RR, 21RL wheels
33 Fluid pressure sensor (master cylinder sensor)
sST control start threshold (control start threshold of the first control means)
k1, k2 control gain (control gain of the first control means)

Claims (7)

A first control means for controlling a value for the slip of each wheel on the basis of the output signal from the wheel speed sensor for detecting the wheel speed of each wheel of the vehicle respectively to a predetermined or less, of the run line state quantity of the vehicle, at least the turning In a vehicle slip control device comprising: second control means for controlling the behavior of the vehicle based on an output signal from a detection means for detecting a state quantity;
Failure determination means for determining failure of the detection means;
A vehicle comprising: a control correction unit that suppresses the control by the second control unit while performing the control by the first control unit from the start of traveling of the vehicle until the failure determination by the failure determination unit is completed. Slip control device. In claim 1,
The control control means is configured to increase the sensitivity of the wheel slip control by the first control means until the failure determination of the detection means by the failure determination means is completed. In claim 2,
The vehicle control apparatus according to claim 1, wherein the control correction means reduces the control start threshold value of the first control means until the failure determination of the detection means by the failure determination means is completed. In claim 2,
The vehicle control apparatus according to claim 1, wherein the control correction means increases the control gain of the first control means until the failure determination of the detection means by the failure determination means is completed. In claim 2 or 4,
When the failure determination of the detection means by the failure determination means is completed and the wheel slip control by the first control means is being executed, the control correction means continues to increase the control sensitivity until the wheel slip control is completed. A slip control device for a vehicle, characterized in that it is configured as follows. In claim 1,
The detection means is at least one of a lateral acceleration sensor that detects the lateral acceleration of the vehicle, a yaw rate sensor that detects the yaw rate of the vehicle, a steering angle sensor that detects the steering angle, or a master cylinder pressure sensor that detects the brake pressure in the master cylinder. A slip control device for a vehicle, characterized in that First control means for controlling a value related to slip of each wheel to a predetermined value or less based on an output signal from a wheel speed sensor for detecting a wheel speed of each wheel of the vehicle, and detection for detecting a predetermined running state quantity of the vehicle A vehicle slip control device comprising: second control means for controlling the behavior of the vehicle based on an output signal from the means;
Failure determination means for determining failure of the detection means;
Control correction means is provided for increasing the sensitivity of wheel slip control by the first control means until the failure judgment by the failure judgment means is completed, while suppressing the control by the second control means.
A slip control apparatus for a vehicle characterized by the above.

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