| 摘要 |
<p>In a brake control system of wheeled vehicles, particularly of motor cars, an arrangement measures the vehicle speed by means of an accelerometer of simple type to produce a signal representing the speed of a braked individual wheel relative to the vehicle speed. The wheel is intermittently braked to be temporarily free-running without slip so that the true vehicle speed is repeatedly measured by an inductive or other speed transmitter. Furthermore, the vehicle speed is continuously, though inaccurately, measured by integration of the output of an accelerometer of a simple cheap type. This integrated output is repeatedly corrected by being updated with the true vehicle speed intermittently measured by the speed transmitter when the wheel is free-running. During those periods during which the wheel is braked and may be lagging (slipping), the measured wheel speed differs from the updated speed represented by the integrated and updated accelerometer output. By comparison of these two speed values, an electrical signal representing the slip is produced and may be used for temporarily releasing the brake means of the vehicle when slip occurs or at least when the ratio of slip to speed passes a predetermined limit value. Any accelerometer output representing a negative retardation, i.e. positive acceleration, is suppressed.</p> |
