Abstract: A slip control device includes a slip detecting device for detecting a slip rate of a drive wheel, an engine control device for reducing an engine output when the slip rate exceeds a first threshold value, and a brake control device for applying a brake force on the drive wheel when the slip rate exceeds a second threshold value. A frictional coefficient detecting device detects a frictional coefficient of a road, on which the vehicle is running, and a threshold determining device provides the first and second threshold values in accordance with the frictional coefficient. The engine output control and brake force control can be effectively utilized for the slip control in the traction control.

Abstract: A traction control system for a vehicle has a sub-throttle valve provided in an intake passage of the engine in series to a main throttle valve which is operatively connected to an accelerator pedal to open and close in response to operation of the accelerator pedal. An engine output controller controls opening of the sub-throttle valve to control the output of the engine so that the slip value of the driving wheels converges on a target slip value. The engine output controller once moves the sub-throttle valve to an initial opening when the slip value of the driving wheels exceeds the target slip value and then controls the opening of the sub-throttle valve to control the output of the engine so that the slip value of the driving wheels converges on a target slip value.

Abstract: A slip control system for a motor vehicle controls respective braking forces in right and left driving wheels and controls an engine output by controlling a throttle opening of a throttle valve so that a slip value of the driven wheel becomes less than a target slip value.

Abstract: An antilock control device for the brake assembly of a motor vehicle having the function of detecting ON and OFF signals supplied from a brake lamp switch and representative of the operative and inoperative positions of the brake pedal. When the signal changes from OFF to ON, which means that the brake pedal has been trodden, the antilock control function is disabled so that the pressure generated in the master cylinder will be directly applied to the wheel cylinders. This state continues until the antilock device detects a locking tendency of any wheel. In addition to the brake lamp switch signals, signals representative of the ON and OFF positions of the accelerator pedal may be supplied to the antilock control device so that the antilock control function will be disabled when either the accelerator pedal position signal changes from OFF to ON or the brake pedal position signal changes from ON to OFF.

Abstract: A slip control system for a vehicle having a differential which distributes engine output to left and right driving wheels suppresses the engine output when the slip of at least one of the driving wheels exceeds a first threshold value. Slips of the left and right driving wheels are periodically detected, and a spin pattern of the driving wheels is periodically determined on the basis of the slips of the left and right driving wheels. Whether the vehicle is running on a split surface road, where the parts of the road surface in contact with the left and right driving wheels have different friction coefficients, is determined on the basis of the present spin pattern and the preceding spin pattern according to a predetermined split surface determining rule. When it is determined that the vehicle is running on a split surface road, the first threshold value is increased.

Abstract: A slip control system for a motor vehicle controls slips in driving wheels and includes a sensor for detecting a slip ratio of each driving wheel and a traction control system for decreasing a slip of each driving wheel by controlling a driving force transmitted to each driving wheel so that the slip ratio of each driving wheel is at least equal to a predetermined desired slip ratio when the slip ratio of the driving wheel becomes equal to the desired slip ratio. An automatic transmission control system controls an automatic transmission by using a first shift property for a normal operation, and a second shift property for a traction control operation which is adapted to determine a relative higher speed stage. A device is provided for switching the first shift property to the second shift property when the traction control operation is started by the traction control system.

Abstract: An anti-skid brake system for the automotive vehicle is disclosed which is arranged to increase or decrease the braking oil pressure periodically on the basis of a comparison between the wheel speed and the assumed vehicle body speed. When the state in which the wheel is incipient to lock before the wheel speed is returned to the assumed vehicle body speed, the braking oil pressure is inhibited from being increased, thereby preventing the assumed vehicle body speed from deviating too far from the actual vehicle body speed. This anti-skid brake system can prevent the wheel from being locked due to having the assumed vehicle body speed set to too low a value relative to the actual wheel speed.

Abstract: A rear steering control system for a motor vehicle includes an antiskid braking system which controls a braking force in a brake device in a respective wheel in accordance with a deceleration condition of the respective wheel so as to prevent wheel locking in a braking operation. The sytem includes a rear steering control system for establishing a ratio of steering amount of the rear wheels to that of the front wheels as a predetermined steering ratio characteristic. An input device inputs an operation condition of the antiskid braking system and an control condition of the brake device for the respective wheel conducted by the antiskid braking system to the rear steering control system. A device is provided in the system for amending the predetermined steering ratio characteristic in accordance with the control condition of the brake device for the respective wheel when the antiskid braking system is in operation.

Abstract: A shift to control for retaining the braking force from the control for elevating the braking force is implemented 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 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 system for a motor vehicle controls slippage of driving wheels and includes, a sensor for detecting a slip ratio of each driving wheel, a device for detecting a reduction in speed of each wheel, and a traction control system for decreasing a slip of each driving wheel by controlling brake fluid pressure in each driving wheel so that the slip ratio of each driving wheel is at least equal to a predetermined desired slip ratio when the slip ratio of each driving wheel becomes equal to the desired slip ratio. The system further includes an antiskid brake system for controlling brake fluid pressure, based on the reduction speed of each wheel, so as to cancel a lock condition of the wheel.

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 vehicle is provided with both a traction control system which reduces driving torque for driving wheels of the vehicle when the driving wheels slip, and an active suspension system which has a cylinder disposed between the vehicle body and each of the wheels of the vehicle and in which suspension properties can be changed by controlling feed and discharge of the hydraulic fluid to and from the cylinders. A control gain of the active suspension system is increased when the traction control system is operating.

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 an antiskid brake system for a vehicle, the braking pressure applied to a wheel is reduced when the deceleration of the rotational speed of the wheel reaches a predetermined value and is increased when the acceleration of the rotational speed of the wheel reaches a predetermined value after reduction of the braking pressure. In a low vehicle speed range lower than a predetermined vehicle speed, the braking pressure is increased at a predetermined rate when the acceleration of the rotational speed of the wheel reaches the predetermined value after reduction of the braking pressure. The predetermined rate is independent from the rotational speed of the wheel and is changed with the friction coefficient of the road surface so that it reduces as the friction coefficient of the road surface reduces.

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 four-wheel-steered vehicle provided with a slip control mechanism which has a slip ratio sensor for detecting the slip ratio of the wheels and controls slip of wheels of the vehicle when the slip ratio of the wheels reaches a first preset value. The four-wheel steering mechanism turns the rear wheels according to first rear wheel turning characteristics in response to turning of the front wheels when the slip ratio of the wheels is smaller than a second preset value which is smaller than the first preset value and turns the rear wheels according to second rear wheel turning characteristics when the slip ratio reaches the second preset value.

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: An antilock control device for the brake assembly of a motor vehicle having the function of detecting ON and OFF signals supplied from a brake lamp switch and representative of the operative and inoperative positions of the brake pedal. When the signal changes from OFF to ON, which means that the brake pedal has been trodden, the antilock control function is disabled so that the pressure generated in the master cylinder will be directly applied to the wheel cylinders. This state continues until the antilock device detects a locking tendency of any wheel. In addition to the brake lamp switch signals, signals representative of the ON and OFF positions of the accelerator pedal may be supplied to the antilock control device so that the antilock control function will be disabled when either the accelerator pedal position signal changes from OFF to ON or the brake pedal position signal changes from ON to OFF.

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.