| 摘要 |
1346678 Anti-skid systems BENDIX CORP 22 Sept 1971 [30 Sept 1970] 44140/71 Heading F2F A vehicle anti-skid system is operated by an assessment of percentage slip derived from measurements of vehicle speed and wheel rotational speed, both measurements being made by Doppler-effect radar. There is one vehicle speed sensor 68 directed towards the road at an angle 0, and it receives back slightly modified signals from the road surface, which it mixes with the transmitted signal to produce a difference frequency. This is converted to a linear voltage analogue. The wheel speeds may be detected by conventional tacho-generators but, as shown, are likewise detected by radar transmitters 70, 72, 74, 76 respectively. The signals derived from these sensors passes through Signal Processor 78 which controls a brakepressure modulator 50 acting, as shown, on all wheels. As shown in Fig. 3, the vehicle and wheel-speed sensors 68, 70 feed into the processor 78 in which the received signals are filtered and combined in a divider 88, the output from which passes to an adder 90. The signal from this is combined in another 92 adder with a programmed wheel slip signal derived from the vehicle speed. The output from this is an error signal, i.e. the difference between actual and programmed slip, and this goes to the modulator 50b to eliminate this error. Total slip is in any case, limited by limiter 100. In an alternative circuit (Fig. 4, not shown) rate-of-charge of slip is fed to the logic unit. |
