| 摘要 |
1344146 Automatic speed and position control BENDIX CORP 12 Oct 1971 [4 Nov 1970] 47402/71 Heading G3R In a vehicle having an automatic speed control system, upon approaching a lead vehicle, the system is over-riden and the spacing between the vehicles controlled to a value determined from the lead vehicle speed, the actual spacing and the rate of change of spacing, under all conditions the speed of the vehicle being limited to a driver selected value. In an embodiment, when a vehicle 16, having a conventional automatic speed control 11, approaches a slower lead vehicle, an adaptive speed control 12 maintains the vehicle at the speed of the lead vehicle and at a safe following distance dependent on the leading vehicle speed. A sensor system 22 e.g. a Doppler radar, optical or microwave transmitter determines the range R and range rate R of the leading vehicle from a signal reflected from that vehicle. A signal processor 23 which receives the range and range rate signals from the sensor system 22, and a trailing vehicle speed signal V 2 from a speedometer 17, calculates, and sends, either a throttle error signal E to the accelerator control 14 if the relative velocities between the vehicles is low and can be corrected by the accelerator, or a brake error signal E b to brake control 24 if the trailing vehicle is travelling faster than the lead vehicle and is within the safe following distance. In either case, the desired speed V 2 set by the driver for the automatic speed control 11 can only be exceeded by manual control of the vehicle i.e. when the adaptive speed control 12 is overriden, for example to overtake. The mathematical equations for E and Eb are given, these signals being derived from the R, R & V 2 signals by circuits as in Figs.3 to 5 (not shown). When cornering, the sensor system which may ignore signals from a range of over 300 feet, rejects erroneous signals reflected from fixed roadside objects. To avoid hunting when the cars are travelling at the same speed and at the safe following distance i.e. zero signals from the sensor system 22, a capacitor memory controls the vehicle from the last R and E signals for a pre-selected time, after which a small acceleration signal accelerates the vehicle and the sensor system resumes control. As the required speed and range is approached, the braking or acceleration signals may be removed, allowing the vehicle to coast to the required speed or position. |
