Abstract: An assumed vehicle body speed is determined on the basis of the wheel speed detected by a wheel speed sensor for each wheel and a slip value indicating the tendency of locking the wheel is determined for a predetermined wheel speed on the basis of the assumed vehicle body speed and a wheel speed of the predetermined wheel. The braking force is controlled on the basis of the slip value. When no braking force is controlled and when at least one of the wheel speeds for all the wheels detected by the wheel speed sensors is larger than the assumed vehicle body speed previously determined, a new assumed vehicle body speed which follows is inhibited from being renewed to a larger value and the new assumed vehicle body speed is set as a value equal to the previous assumed vehicle body speed.

Abstract: A vehicle traction control device having a control device for controlling the torque of the drive wheels by controlling the throttle in order to match the slip rate of the drive wheels with a target slip rate in order to prevent excessive slip caused by excessive torque in the drive wheels. The traction control is provided with a device for determining whether or not the road being driven on is a rough road or not. When the above device sends a signal to the control that the road is rough, the engine gain in the throttle is made smaller when the throttle closed relative to the engine gain and throttle of a normal road. In another embodiment, when the road is rough, the engine gain is made larger when the throttle is opened relative to the engine gain and throttle of a normal road. Also disclosed is a control in which the engine gain in the throttle control is made larger when the throttle is opened and is made smaller when the throttle is closed relative to the engine gain and throttle of a normal road.

Abstract: A first estimated vehicle speed is calculated on the basis of the highest of the speeds of the wheels and the deceleration of the vehicle. A second estimated vehicle speed which begins to reduce from a predetermined value at a predetermined rate independent from the change in the highest of the speeds of the wheels from the time the first estimated vehicle speed falls to the predetermined value is calculated. A slip ratio of each wheel is calculated on the basis of the first estimated vehicle speed when the first estimated vehicle speed is not lower than the predetermined value and on the basis of the second estimated vehicle speed when the first estimated vehicle speed is lower than the predetermined value. The braking force applied to each wheel is controlled so that the slip ratio of the wheel converges on a target slip ratio.

Abstract: A slip control mechanism of a motor vehicle has a brake provided for each driving wheel, a first detection device means for detecting slip of each driving wheel, a second detection device for detecting if a predetermined condition has been met during a starting period of the vehicle, and a slip control device for operating the brake for providing each driving wheel with braking force when an excessive slip is detected, based on signals from the first detection device, to thereby eliminate such excessive slip. The slip control device controls the brake for the respective driving wheels whereby substantially the same amount of braking force is applied to the driving wheels when the second detection device detects that the predetermined condition is not met. The slip control device also controls the brake for the respective driving wheels independently in accordance with signals from the first detecting device when the second detecting device detects that the predetermined condition is met.

Abstract: A shift is implemented from the control for elevating the braking force to the control for retaining the braking force when deceleration of the wheel exceeds a first predetermined threshold value when the wheels are braked. The first predetermined threshold value is so set as to become smaller as an assumed road surface friction coefficient .mu. is smaller. The first threshold value is further altered to a larger value by altering the assumed road surface friction coefficient .mu. to a higher one when the period of time required from the start of the control for elevating the braking force to the start of the following control for retaining the braking force is equal to or shorter than a predetermined period of time.

Abstract: A braking force control system controls the brake fluid pressure applied to the wheel during braking when each of the wheels of the vehicle tends to lock so that the slip ratio of the wheel converges on a target slip ratio. The brake fluid pressure is once fixed at the beginning of the braking force control, and when the slip ratio falls below the target slip ratio by fixing the brake fluid pressure, the brake fluid pressure is increased at a first rate, and when the slip ratio does not increase to a predetermined slip ratio in a predetermined time after the slip ratio falls below the target slip ratio or when the rate of increase of the slip ratio after the slip ratio falls below the target slip ratio is lower than a predetermined rate, the brake fluid pressure is increased at a second rate which is higher than the first rate.

Abstract: In performing slip control such as traction control or ABS control, a control degree for slip control is changed in accordance with a temperature of outside air, or outside air temperature. The slip control system enhances response to slip control on a road surface having a lower road surface friction coefficient .mu., or a slippery road, and prevent a frequent execution of slip control on a road surface having a higher road surface friction coefficient .mu., by appropriating the setting of the road surface friction coefficient .mu. in accordance with the outside air temperature. A mode of changing the control degree for slip control includes, for example, a change of the condition for starting slip control, a change of a target value for slip control, and a change of an initial value of the road surface friction coefficient .mu., in accordance with the outside air temperature.

Abstract: A slip of the driven wheels is converged by causing the torque generated by the engine to be reduced and applying braking force when a slip of the driven wheel becomes large during accelerating. Control of the application of the braking force to the left-hand and right-hand driven wheels is made individually and separately from each other. When such an incident occurs as causing no normal control of decreasing the torque generated by the engine to be made, the contents of control of application of the braking force is changed so as to apply the same degrees of the braking force to both of the left-hand and right-hand driven wheels.

Abstract: In a slip control system for a vehicle a slip ratio of driving wheels of the vehicle is detected, and the slip of the driving wheels is controlled to converge on a predetermined target slip ratio when the slip ratio of the driving wheels exceeds a predetermined threshold slip ratio. When the vehicle is running a rough road, the threshold slip ratio is increased. The running condition of the vehicle is detected and increase of the threshold slip ratio is inhibited depending on the running condition of the vehicle.

Abstract: A torque converter with a lockup clutch is interposed between an engine and a driven wheel, and the lockup clutch is coupled or uncoupled on the basis of a predetermined lockup characteristic. When a slip value of the driven wheel against a road surface reaches a given value or higher, torque to be applied to the driven wheel is decreased to thereby perform slip control. During this slip control, the lockup clutch is forced to be uncoupled prior to the lockup characteristic. The forcibly uncoupled state of the lockup clutch is maintained for a given period of time from the time when the slip control ends.

Abstract: A driving torque adjusting system for adjusting a driving torque acting upon driven wheels, for example, a throttle valve for adjusting an output power or torque from the engine, is subjected to feed-back control at a set response velocity so as for an actual slip value of the driven wheel to reach a given target value. When the actual slip value of the driven wheel is equal to or larger than a set value larger than the target value, only the set response velocity in the direction of reducing the driving torque acting upon the driven wheels is corrected to become larger when the actual slip value is smaller than the set value. Preferably, the set response velocity is set smaller as a friction coefficient on a road surface is smaller in both cases where the torque acting upon the driven wheels is increased and decreased. An amount to correct the set response velocity, i.e.

Abstract: When a slip value of the driven wheel on a road surface reaches a predetermined value, the slip control is implemented to apply a braking force to the driven wheel as well as to decrease torque to be generated by the engine. When the brake is operated manually, or when a foot brake is stepped down, only the slip control by application of the braking force to the driven wheel is inhibited.

Abstract: A slip control mechanism of a car has a hydraulic booster for driving a master cylinder for providing hydraulic pressure to a first brake provided for each driven wheel, a second brake provided for each driving wheel, a slip detection device for detecting the slip of driving wheels, a slip control device for operating the second brake, based on signals from the slip detecting device, by using the operating oil of the hydraulic booster as operating oil of the second brake so as to reduce the slip of the driving wheels, the control device comprising a pressure control valve for controlling hydraulic pressure of the operating oil of the second brake, including a pressure reducing valve for reducing the hydraulic pressure of the operating oil of the second brake, detection device for detecting completion of the slip control by the operation of the second brake, and a release device for opening the pressure reducing valve for a predetermined time so as to release the operating oil of the second brake on the occasi

Abstract: A slip control system for a vehicle contains a first control unit for implementing feedback control of torque applied to the driven wheels so as to allow an actual slip value of the driven wheel to reach a predetermined target value. There are set a first judgment value larger than the target value and a second judgment value smaller than the first judgment value. A second control unit is provided for temporarily reducing the torque applied to the driven wheel by a predetermined decrement, in place of the feedback control, when the actual slip value reaches the first judgment value or larger than the first judgment value. There is further provided a third control unit for gradually reducing the torque applied to the driven wheel, in place of the feedback control, when the actual slip value of the driven wheel does not reach the second judgment value or a value smaller than the second judgment value even if a predetermined period of time elapses after start of control by the second control unit.

Abstract: A power train control system for controlling power to be transmitted to a traction wheel of a vehicle from a vehicle engine through an automatic transmission shifts its speed range according to shift patterns depending upon speed of the vehicle and a load of the vehicle engine. When slippage occurring on the traction wheel is detected, the automatic transmission is caused to shift its speed range according to a specific shift pattern for traction control which predetermined according to at least a rotational speed of a driven wheel of the vehicle so as to control the power transmitted to the traction wheels from the vehicle engine, thereby eliminating the slippage.

Abstract: Slip control is carried out so as to reduce torque applied to the driven wheels by reducing torque generated by the engine when a slip value against the driven wheels on pavement is larger than a predetermined value. A shift characteristic of the automatic transmission interposed between the engine and the driven wheels is set as a first shift characteristic which is a basic characteristic at the time of ordinary running where no slip control is carried out and as a second shift characteristic set so as to become at least unlikely to cause downshifting during slip control compared with said first shift characteristic. As the slip control terminates, a return of the first shift characteristic is prohibited when the torque generated by the engine is large (for example, when a degree of operation of an accelerator is not zero) or when downshifting is caused if based on the first shift characteristics.

Abstract: When the driven wheel of the vehicle slips against the road surface to a large extent, such a large slip of the driven wheel can be converged by reducing torque to be applied to the driven wheel by slip control, i.e., by control the throttle valve for adjusting a load of the engine in a direction of forcibly closing the throttle valve prior to operation of the accelerator. In a region of the opening angle of the accelerator nearby its full open region, for example, accounting for 75% or more, a control-unreactive region is provided which is unreactive to slip control, thereby preventing the throttle valve from lowering a given opening angle, for example, 25%. This arrangement can retain the opening angle of the accelerator nearby its full open position even if slip control cannot work normally, thereby ensuring an open state of the throttle valve and allowing the vehicle to run at least to a tune-up factory nearby.

Abstract: When a slip value of the driven wheel of a vehicle on a road surface reaches a predetermined value, the braking force is applied to the driven wheel by way of slip control. The slip control by application of the braking force to the driven wheel is inhibited when the vehicle speed reaches a high speed above a predetermined vehicle speed.

Abstract: A constant-speed cruising control system for a vehicle having an automatic transmission includes a vehicle speed controller which controls the throttle valve of the engine on the basis of the difference between a target vehicle speed and the actual vehicle speed so that the latter approaches the former, a gear shifting mechanism which receives a gear shifting command and shifts the gear stage of the automatic transmission according to the content of the gear shifting command which it receives, and a gear-shifting controller which receives an engine load signal representing the load on the engine and a speed difference signal representing the difference between said target vehicle speed and the actual vehicle speed, and delivers to the gear shifting mechanism a gear shifting command which requires the gear shifting mechanism to shift the gear stage down either when the load on the engine is not lighter than a first preset value or when the load on the engine is lighter than the first preset value and heavier t

Abstract: An automatic transmission control system for controlling an automatic transmision for use in a vehicle provided with a throttle control system which electrically controls a throttle valve to control the engine output according to the amount of depression of the accelerator pedal and a constant-speed cruising control system which makes the vehicle cruise at a desired constant speed includes a first gear-stage setting system which designates a gear stage of the automatic transmission on the basis of a first gear-shifting pattern, which applies when the constant-speed cruising control is not performed, and in which the gear stages of the automatic transmission are related to the detected amount of depression of the accelerator pedal and the vehicle speed or a value corresponding to the vehicle speed, and a second gear-stage setting system which designates a gear stage of the automatic transmission on the basis of a second gear-shifting pattern, which applies when the constant-speed cruising control is performed