A method for determining a coefficient-of-friction, the method including braking a first wheel of a vehicle such that a slip between the first wheel and a roadway is less than a slip between a second wheel of the vehicle and the roadway, and determining a coefficient-of-friction between the first wheel and the roadway based on the behavior of the first wheel during the braking. The method optionally including hazard braking the vehicle.

A method for determining a coefficient-of-friction, the method including braking a first wheel of a vehicle such that a slip between the first wheel and a roadway is less than a slip between a second wheel of the vehicle and the roadway, and determining a coefficient-of-friction between the first wheel and the roadway based on the behavior of the first wheel during the braking. The method optionally including hazard braking the vehicle.

A motor vehicle brake system is specified. The brake system comprises a driving dynamics regulation system, which is designed to carry out a wheel-specific regulating intervention on each of a plurality of vehicle wheels, and an electrically controllable actuator, which is designed to generate or boost a service brake force. The brake system further comprises a control, which is designed, in the event of an identified loss of function of the driving dynamics regulation system, to select one of at least two vehicle wheels on which a regulating intervention by the driving dynamics regulation system would be required and to electrically control the actuator on the basis of a regulating intervention determined for the selected vehicle wheel.

A braking control method according to friction of road surface includes computing a real-time wheel speed according to a signal received from a wheel speed sensor; storing the real-time wheel speed as a wheel initial velocity when a braking event occurs; determining a relative-peak value according to the real-time wheel speed; estimating a vehicle deceleration according to the relative-peak value and the wheel initial velocity; computing an adjustment parameter according to the vehicle deceleration and a tire slip threshold, wherein the adjustment parameter reflects friction coefficient of road surface; and adjusting time length of an enhancement stage in an enhance-pressure control period of a stepped pressure-increasing phase according to the adjustment parameter; or adjusting time length of a reduction stage in a reduce-pressure control period of a stepped pressure-decreasing phase according to the adjustment parameter.

A braking control method according to friction of road surface includes computing a real-time wheel speed according to a signal received from a wheel speed sensor; storing the real-time wheel speed as a wheel initial velocity when a braking event occurs; determining a relative-peak value according to the real-time wheel speed; estimating a vehicle deceleration according to the relative-peak value and the wheel initial velocity; computing an adjustment parameter according to the vehicle deceleration and a tire slip threshold, wherein the adjustment parameter reflects friction coefficient of road surface; and adjusting time length of an enhancement stage in an enhance-pressure control period of a stepped pressure-increasing phase according to the adjustment parameter; or adjusting time length of a reduction stage in a reduce-pressure control period of a stepped pressure-decreasing phase according to the adjustment parameter.

A brake fluid pressure control device for a vehicle that includes a wheel speed obtaining device to obtain wheel speed, and a vehicle body deceleration calculating means to calculate a vehicle body deceleration on the basis of the wheel speed. If a condition is satisfied in which the vehicle body deceleration continues to stay at a low rate of less than or equal to a predetermined threshold value for a predetermined period of time, the pressure increasing rate in pressure increasing control is altered to a higher value than before the condition is satisfied. The brake fluid pressure of a brake caliper can quickly be brought close to the fluid pressure of a master cylinder. Therefore, it is possible to improve the brake responsiveness when the brake is re-operated by the driver during the ABS control, thereby reducing the driver's feeling of wrongness and strangeness.

A brake fluid pressure control device for a vehicle that includes a wheel speed obtaining device to obtain wheel speed, and a vehicle body deceleration calculating means to calculate a vehicle body deceleration on the basis of the wheel speed. If a condition is satisfied in which the vehicle body deceleration continues to stay at a low rate of less than or equal to a predetermined threshold value for a predetermined period of time, the pressure increasing rate in pressure increasing control is altered to a higher value than before the condition is satisfied. The brake fluid pressure of a brake caliper can quickly be brought close to the fluid pressure of a master cylinder. Therefore, it is possible to improve the brake responsiveness when the brake is re-operated by the driver during the ABS control, thereby reducing the driver's feeling of wrongness and strangeness.

The invention obtains a controller and a control method capable of improving safety by automatic emergency deceleration action while suppressing a motorcycle from falling over. The invention also obtains a brake system that includes such a controller. In the controller, the control method, and the brake system according to the invention, a control mode that causes the motorcycle to take the automatic emergency deceleration action is initiated in response to trigger information generated in accordance with peripheral environment of the motorcycle. In the control mode, automatic emergency deceleration that is deceleration of the motorcycle generated by the automatic emergency deceleration action is controlled in accordance with a change rate of a state amount that is related to posture of the motorcycle during turning travel.

Disclosed is a brake control apparatus which starts ABS control on the basis of slip ratio speed and which reduces a variation in the slip ratio at the time of start of the ABS control. A brake ECU computes a braking stiffness BS** in a linearly increasing region of a μ-S characteristic, and computes a slip ratio speed reference value dSref**/dt by dividing a changing speed dFxc**/dt of braking force of a wheel by the braking stiffness BS**. The brake ECU computes, as a slip ratio speed threshold, a value ((dSref**/dt)+dSn) by adding a slip ratio speed noise offset value dSn to the slip ratio speed reference value dSref**/dt and starts ABS control when the slip ratio speed dSc**/dt of the wheel exceeds the slip ratio speed threshold.

The invention relates to a signal-processing device (402) for a vehicle having an ABS unit (404) and multiple wheels, each of which is assigned a sensor (S1, S2, S3, S4) for wheel signal generation. The signal-processing device (402) is designed to detect (602) a failure of a wheel signal, to form (604) a substitute signal for the failed wheel signal using the wheel signal of at least one sensor assigned to a wheel that is not affected by the failure, and to supply (606) the substitute signal to the ABS unit (404). The invention also relates to an ABS system (400) having the signal-processing device (402) and an ABS unit (404), a vehicle having the ABS system (400), a signal-processing method for a vehicle having an ABS unit (404), a computer programme having computer code for carrying out the signal-processing method, as well as a control unit containing the computer programme.