| 摘要 |
<p>An electro-hydraulic braking system of the type capable of operating in a brake-by-wire mode wherein hydraulic pressure is applied from a charged pressure accumulator to braking devices (18a-18d) at the vehicle wheels in proportion to the driver's braking demand as sensed electronically at a brake pedal (10), and in a push-through mode wherein hydraulic pressure is applied to the braking devices at the vehicle wheels by way of a master cylinder (34) coupled mechanically to the brake pedal (10), and which includes a hydraulic simulator (38) which is connected hydraulically to the master cylinder (34) for providing improved feel for the driver through the brake pedal in the push-through operating mode. In order to reduce fluid consumption from the pressure accumulator, the occurrence of a progressively falling trend in the accumulator pressure is arranged to be detected and, when such an occurrence is detected, the brake pressure is modified in such a manner that the brake fluid consumption by the wheel brakes is reduced, whilst at least maintaining the demanded vehicle deceleration. Brake pressure consumption can be reduced by (a) limiting the peak(s) of the maximum brake pressure and/or the peak(s) of the minimum brake pressure, and/or (b) clipping the ceiling of the maximum brake pressure and/or the floor of the minimum brake pressure, and/or (c) changing the rise rate and/or falling rate of the brake pressure, and/or (d) reducing the boost ratio between the driver's braking demand and the brake pressure; and/or (e) slowing up the pressure decay rate. <IMAGE></p> |
