Vehicle speed control system

摘要

A feedback calculator and a controller are disclosed which energize a throttle valve driver so that a vehicle speed Vs may be brought into coincidence with a target vehicle speed Vo which is instructed by a driver. The feedback calculator calculates a target acceleration AT on the basis of a vehicle speed Vs and a target speed Vo, and also detects a running acceleration Aa of the vehicle and calculates a deviation of the running acceleration Aa with respect to the target acceleration AT, Ad=AT-Aa. It chooses a high gain G when the deviation Ad is positive and its change dAd is also positive, and chooses a low gain G when the deviation Ad is negative and its change dAd is also negative, thus deriving a controlled variable D having a magnitude which depends on the deviation Ad and the gain G. The controller energizes the throttle valve driver in accordance with the controlled variable D, thus driving the throttle valve for opening or closing at a rate which depends on the controlled variable D. In this manner, no substantial steady-state speed deviation is produced.