Abstract: A brake system for a vehicle includes an electrically operated parking brake drive device which generates an operating force for operating the wheel brakes or dedicated parking brakes in response to energization, and which operates even upon cancellation of the energization while in the operated state. A braking force related amount detector detects a physical quantity related to a braking force exhibited by each of the hydraulic pressure operated wheel brakes. When a detected physical quantity exceeds a reference value in a stopped state of the vehicle, a controller energizes the electrically operated parking brake drive device. Thus, the frequency of operation of the electrically operated parking brake drive device is decreased while eliminating inconvenient operations required to operate the electrically operated parking brake drive device, thereby reducing noise and improving durability.

Abstract: A brake system for a vehicle includes an electrically operated parking brake drive device which generates an operating force for operating the wheel brakes or dedicated parking brakes in response to energization, and which operates even upon cancellation of the energization while in the operated state. A braking force related amount detector detects a physical quantity related to a braking force exhibited by each of the hydraulic pressure operated wheel brakes. When a detected physical quantity exceeds a reference value in a stopped state of the vehicle, a controller energizes the electrically operated parking brake drive device. Thus, the frequency of operation of the electrically operated parking brake drive device is decreased while eliminating inconvenient operations required to operate the electrically operated parking brake drive device, thereby reducing noise and improving durability.

Abstract: When a shift position is shifted from an R range to a D range and when the shift position is shifted from the D range to the R range, an electrically-operated parking brake device is automatically cancelled. In this manner, the electrically-operated parking brake device is cancelled without waiting for the depression of an accelerator pedal with a driver's intention to start a vehicle taken into consideration. Therefore, it is possible not only to alleviate a burden on the driver in canceling the electrically-operated parking brake device, but also to prevent an abrupt starting of the vehicle due to the cancellation of the electrically-operated parking brake device while the accelerator pedal is being depressed to transmit a large driving force to driven wheels.

Abstract: An electric parking brake system that includes a parking brake, and an electric motor, wherein the parking brake is activated by the electric motor. Operation of the parking brake is controlled such that a vehicle is decelerated at a target deceleration of a predetermined magnitude when an operation command to operate the parking brake is issued by a driver via an operation switch while the vehicle is running. If a service brake fails while a vehicle is running, when the driver depresses the operation switch to issue the operation command to a parking brake to brake the vehicle, the parking brake is controlled such that the vehicle is decelerated at the target deceleration of the predetermined magnitude set on the basis of the number of times of depressing the operation switch.

Abstract: A vehicle brake control system includes an improved ACC system for controlling the operation of a brake actuator and a throttle actuator, based on a signal from a preceding vehicle detector such as a radar device, so that a subject vehicle tracks a preceding vehicle. After a regular brake device is actuated to stop the subject vehicle, an EPB ECU disengages the regular braking device and, instead, actuates an electrically initiated and mechanically maintained parking brake device, so as to temporarily maintain the subject vehicle in a stationary state. Once the electric parking brake device is initiated, its braking state is mechanically maintained even if the flow of current is cut off. Therefore, neither the regular brake device nor the electric parking device consume power while the vehicle is in a stationary state, thereby saving power and minimizing electrical heat generation.

Abstract: If a service brake fails while a vehicle is running, when the driver depresses an operation switch to issue an operation command to a parking brake to brake the vehicle, the parking brake is controlled such that the vehicle is decelerated at a target deceleration of a predetermined magnitude set on the basis of the number of times of depressing the operation switch. Consequently, even if the temperature and degree of wear of a friction material of the parking brake vary, the vehicle can be decelerated at the target deceleration at all times, whereby a stable braking effect which is not affected by the conditions of the friction material of the parking brake can be obtained. Moreover, since the magnitude of the target deceleration is set according to the number of times of depressing the operation switch, a deceleration required by the driver can be generated in an ensured fashion.

Abstract: When a shift position is shifted from an R range to a D range and when the shift position is shifted from the D range to the R range, an electrically-operated parking brake device is automatically cancelled. In this manner, the electrically-operated parking brake device is cancelled without waiting for the depression of an accelerator pedal with a driver's intention to start a vehicle taken into consideration. Therefore, it is possible not only to alleviate a burden on the driver in canceling the electrically-operated parking brake device, but also to prevent an abrupt starting of the vehicle due to the cancellation of the electrically-operated parking brake device while the accelerator pedal is being depressed to transmit a large driving force to driven wheels.

Abstract: An electrically operated parking brake apparatus that includes an electric motor and a screw mechanism The screw mechanism includes a screw-threaded shaft adapted to be rotationally driven by the electric motor, and a nut member meshing with the screw-threaded shaft, the nut member being movable along the screw-threaded shaft by the rotation of the screw-threaded shaft. The parking brake apparatus also includes a transmission member connected to the nut member for transmitting a brake operating force to a wheel brake, and a rotation preventing unit for preventing the rotation of the screw-threaded shaft so as to hold the brake operating force by fixing the position of the nut member relative to the screw-threaded shaft. The rotation preventing unit in one embodiment is an electromagnetic brake for confining the screw-threaded shaft to a stationary portion of a vehicle body.

Abstract: A vehicle brake control system includes an improved ACC system for controlling the operation of a brake actuator and a throttle actuator, based on a signal from a preceding vehicle detector such as a radar device, so that a subject vehicle tracks a preceding vehicle. After a regular brake device is actuated to stop the subject vehicle, an EPB ECU disengages the regular braking device and, instead, actuates an electrically initiated and mechanically maintained parking brake device, so as to temporarily maintain the subject vehicle in a stationary state. Once the electric parking brake device is initiated, its braking state is mechanically maintained even if the flow of current is cut off. Therefore, neither the regular brake device nor the electric parking device consume power while the vehicle is in a stationary state, thereby saving power and minimizing electrical heat generation.

Abstract: An electrically operated parking brake apparatus that includes an electric motor and a screw mechanism The screw mechanism includes a screw-threaded shaft adapted to be rotationally driven by the electric motor, and a nut member meshing with the screw-threaded shaft, the nut member being movable along the screw-threaded shaft by the rotation of the screw-threaded shaft. The parking brake apparatus also includes a transmission member connected to the nut member for transmitting a brake operating force to a wheel brake, and a rotation preventing unit for preventing the rotation of the screw-threaded shaft so as to hold the brake operating force by fixing the position of the nut member relative to the screw-threaded shaft. The rotation preventing unit in one embodiment is an electromagnetic brake for confining the screw-threaded shaft to a stationary portion of a vehicle body.

Abstract: A driving-force controller in a vehicle in which, when an accelerator pedal is depressed to initially move the vehicle at a time t.sub.1, if a state in which a vehicle speed is zero due to slippage of driven wheels continues for a predetermined time, it is judged that the vehicle is on a road surface having an extremely low road surface friction coefficient. If a driven wheel speed and the vehicle speed become zero at a time t.sub.4 because a driver abandons initial acceleration and releases an accelerator pedal, a gear shift stage of an automatic transmission is forcibly shifted to a second gear shift stage, and a target slip rate set in a traction control device is switched to a decreased value. As a result, when the driver depresses the accelerator pedal to restart the vehicle at a time t.sub.5, excessive slippage is suppressed by a decrease in driven wheel torque so that the vehicle begins moving smoothly. If a driven wheel slip rate exceeds the decreased target slip rate at a time t.sub.