| 摘要 |
<p>To enable the driver of a diesel driven vehicle to have control of engine speed (n) in the event of the vehicle exceeding a permitted velocity (vlim) with the gearbox in neutral and when a vehicle velocity limiting system is incorporated in the electronic diesel control (EDC), the speed/velocity ratio (n/v) is differentiated and the magnitude (Y) of the value (Y) obtained by the differentiator is fed to a tolerance threshold comparator (18). When the gearbox is in neutral, and the engine speed (n) is changing (falling), the resulting signal (S) is applied to the EDC to switch off the velocity limiting mode. If the engine speed stabilizes before the driver has engaged a gear, the signal (S) from the comparator disappears. A delay circuit (20) prevents the velocity limiting system from being switched on again before elapse of a delay of say, 5 sec. In the event that the vehicle is coasting downhill with a velocity (v) exceeding the permitted velocity (vlim) and the engine speed (n) is below a preselected maximum (nmax), a comparator (22) prevents the velocity limitation from being established after the above-mentioned delay of 5 sec.</p> |
