Abstract: A vehicle motion control device which detects an abnormality of an automatic hydraulic pressure generator having a master cylinder, a booster which boosts the master cylinder and a booster actuator which actuates the booster irrespective of brake pedal operation and performs an appropriate transaction upon detecting the abnormality. The vehicle motion control device includes the automatic hydraulic pressure generator, a hydraulic pressure control valve disposed between the automatic hydraulic pressure generator and a wheel cylinder, and a controller performing the automatic pressure increase control by actuating the hydraulic pressure control valve and the booster actuator according to the vehicle running condition.

Abstract: A vehicle motion control system which generates a minimized switching noise when a hydraulic pressure control valve is switched. The vehicle motion control system includes an automatic hydraulic pressure generator generating a hydraulic pressure irrespective of a brake pedal operation and a hydraulic pressure control valve adjusting the hydraulic brake pressure by opening or blocking a connection between the automatic hydraulic pressure generator and a wheel brake cylinder, and performs a motion control by controlling at least the hydraulic pressure control valve in accordance with the motion of a vehicle.

Abstract: A vehicle motion control device reduces noise resulting from operation of a vacuum booster when an automatic pressure control is performed by properly controlling the energization of a linear solenoid of a booster actuator. An automatic hydraulic pressure generator is controlled in accordance with the vehicle motion condition and a hydraulic pressure control valve device is controlled to perform the automatic pressure control. A target electric current of the linear solenoid for actuating the vacuum booster is instantaneously increased to a starting target value which corresponds to an electric current value immediately before starting the operation of the vacuum booster and which is less than a maximum value of the target electric current, and then is gradually increased approximately to the maximum value of the target electric current.

Abstract: The vehicle motion control system includes an automatic hydraulic pressure generator generating a hydraulic pressure irrespective of a brake pedal operation and a hydraulic pressure control valve adjusting the hydraulic brake pressure by opening or blocking a connection between the automatic hydraulic pressure generator and a wheel brake cylinder. The system includes vacuum pressure detecting means to adjust the hydraulic brake pressure in a appropriate condition. In response to the vacuum pressure detecting means, vehicle motion is controlled in the direction that the vehicle motion control is restricted under the vacuum pressure which drives said vacuum booster is relatively small. Also, the duration of the hydraulic brake pressure increase is controlled in the direction longer under the vacuum pressure which drives said vacuum booster is relatively small.

Abstract: A vehicle driving condition detection device is adapted to detect a vehicle running along a banked or laterally sloping road, as well as a lateral acceleration, and sideslip angle with good accuracy. The sideslip angle is estimated at a vehicle-body sideslip angle estimating circuit based on a steering angle &dgr;f, a lateral acceleration ÿ, a yaw rate {dot over (&thgr;)}, and a vehicle speed V. In addition, using a differentiating device, the estimated sideslip angle is differentiated to calculate a slip angular velocity. A subtracting device is provided at which a deviation is calculated between the slip angular velocity and a slip angular velocity detected at a slip angular velocity calculating circuit. The deviation can detect a banked or laterally sloping road due to the fact that the detected slip angular velocity at the slip angular velocity calculating circuit includes the gravity acceleration component that depends on the slope or bank of the road.

Abstract: The present invention is directed to a vehicle motion control system, which includes wheel brake cylinders, an automatic hydraulic pressure generating apparatus for generating a hydraulic braking pressure irrespective of operation of a brake pedal, a hydraulic pressure control valve device disposed between the pressure generating apparatus and the wheel brake cylinders to control the hydraulic braking pressure in each wheel brake cylinder, and a controller for controlling the pressure generating apparatus and the valve device in response to conditions of vehicle motion, and performing an automatically pressurizing control to the wheel brake cylinders at least when a brake pedal is not depressed, to perform a vehicle motion control.

Abstract: A brake control device for a vehicle includes a brake pedal, vehicle wheels, wheel brake cylinders, an automatic hydraulic pressure generating device, a pressure control valve unit, and an automatic brake control unit for controlling the pressure control valve unit in response to a vehicle driving condition. The brake control device for the vehicle regulates any of the pressure control valve unit corresponding to the wheels in response to the brake pedal operation when the automatic brake control is performed under the brake pedal being operated. Therefore, the brake control device resembles the brake hydraulic pressure of the wheel brake cylinders corresponding to the controlled pressure control valve to the brake pedal depression. The brake control device generates a vehicle deceleration in response to a brake pedal operation when an automatic brake pressure increase control is performed at any of the vehicle wheels when the brake pedal is operated.

Abstract: The present invention is directed to a yaw rate detecting system for a vehicle, which includes a yaw rate sensor for measuring a yaw rate of the vehicle. The apparatus is adapted to determine a stopped state of the vehicle, set a zero point at the yaw rate measured by the yaw rate sensor when the stopped state of the vehicle is determined, and calculate an actual yaw rate in response to an output of the yaw rate sensor, on the basis of the zero point. The actual yaw rate is calculated by subtracting the yaw rate at the zero point from the yaw rate measured by the yaw rate sensor. It may be so arranged that a desired yaw rate is set on the basis of a vehicle speed and a steering angle, and the zero point is corrected in response to a comparison of the desired yaw rate and the actual yaw rate. For example, a temporary zero point is set when the stopped state of the vehicle is determined, and a deviation between the desired yaw rate and the actual yaw rate is calculated.

Abstract: A vehicle running condition judgment device for accurately detecting a change in a road surface condition and a vehicle's limit running condition. With substitution of respective tire characteristics and a detected state quantity into a vehicle motion model, vehicle slip angles are estimated for respective assumed road surface conditions. Based on the current state quantity and the last estimated vehicle slip angle, currently estimated vehicle slip angles for the respective assumed road surface conditions are compensated. A differential operation section calculates an estimation value of a vehicle slip angular velocity for each of the assumed road surface conditions based on the compensated vehicle slip angles for the respective assumed road surface conditions. Meanwhile, an operation section calculates a detection value of a vehicle slip angular velocity based on the detected state quantity.

Abstract: The present invention is directed to a yaw rate detecting system for a vehicle, which includes a yaw rate sensor for measuring a yaw rate of the vehicle. The apparatus is adapted to determine a stopped state of the vehicle, set a zero point at the yaw rate measured by the yaw rate sensor when the stopped state of the vehicle is determined, and calculate an actual yaw rate in response to an output of the yaw rate sensor, on the basis of the zero point. The actual yaw rate is calculated by subtracting the yaw rate at the zero point from the yaw rate measured by the yaw rate sensor. It may be so arranged that a desired yaw rate is set on the basis of a vehicle speed and a steering angle, and the zero point is corrected in response to a comparison of the desired yaw rate and the actual yaw rate. For example, a temporary zero point is set when the stopped state of the vehicle is determined, and a deviation between the desired yaw rate and the actual yaw rate is calculated.

Abstract: The present invention is directed to a brake control system, which includes wheel brake cylinders, a master cylinder, a reservoir communicated with the wheel brake cylinders, normally open solenoid valves disposed between the master cylinder and the wheel brake cylinders, respectively, normally closed solenoid valves disposed between the wheel brake cylinders and the reservoir, respectively, a hydraulic pump for supplying the brake fluid to a passage for connecting the master cylinder with the normally open valves, and an automatically pressurizing device (e.g., a vacuum booster with a changeover valve) which is provided for advancing the master piston irrespective of operation of the pump and the brake pedal to generate hydraulic braking pressure from the master cylinder.

Abstract: The object to be achieved by the present invention is to improve accuracy in determining whether or not it is necessary to terminate antiskid control and to reduce the frequency with which the control is terminated. The solution proposed by the present invention is to stop operation of a hydraulic pump before it is determined that the antiskid control should be terminated during the duty pressure increase operation, whereby fluid pressure in a wheel brake can be raised to a level of fluid pressure in a master cylinder before it is determined that the antiskid control should be terminated, to continue the antiskid control as long as the wheel tends to be locked and to terminate the antiskid control when the wheel does not tend to be locked.

Abstract: According to the present invention, the gradient of duty pressure increase can be adjusted to a best possible value even when an M/C pressure has varied. For example, duty ratio is set to a first set value when a difference between the M/C pressure and a wheel locking pressure is equal to or larger than a predetermined value and to a second set value for a longer pressure increase duration when the difference is smaller than the predetermined value. Then, a brake fluid pressure control valve is operated so that the duty pressure can be increased according to the duty ratio.

Abstract: An anti-skid control system for an automotive vehicle includes a hydraulic pressure source, a wheel brake for braking a wheel, a pressure control valve interposed between the hydraulic pressure source to the wheel brake in order to regulate a hydraulic braking pressure supplied from the hydraulic pressure source and the wheel brake, the pressure control valve being brought into a duty-cycle pressure-increasing mode operation and a pressure-decreasing mode operation for increasing and decreasing the hydraulic braking pressure, respectively. The duty-cycle pressure-increasing mode operation are repeated such that the pressure-decreasing mode operation is established therebetween. A later pressure-increasing mode operation is treated as a succession of the previous pressure-increasing mode operation if a time duration required for the pressure-decreasing mode operation between the previous and later pressure-increasing mode operations is less than a set value.

Abstract: An anti-skid control device includes a front wheel brake fluid pressure control unit for determining whether the brake fluid pressure in the front wheel brake should be increased or decreased according to the rotational condition of the front wheel which is braked by the front wheel brake, and for activating a first electromagnetic valve and a hydraulic pressure pump to decrease or increase the brake fluid pressure in the front wheel brake according to a determination. A rear wheel brake fluid pressure control unit determines whether the brake fluid pressure in the rear wheel brake should be increased or decreased according to the rotational condition of the rear wheel which is braked by the rear wheel brake, and activates the second electromagnetic valve and the hydraulic pressure pump driven to decrease or increase the brake fluid pressure in the rear wheel brake according to a determination.