Cruise control system for automotive vehicle

摘要

A cruise control system for an automotive vehicle which automatically controls the throttle valve opening to maintain the vehicle speed constant without a driver's operation of the accelerator pedal once the vehicle speed is set to a desired value, is designed so that acceleration at the time of operating an increase set switch or resume switch is increased to ensure a comfortable drive while ascending a long slope. To this end, the cruise control system is provided with an overdrive controller which releases overdrive at the time of operating the increase set switch and resumes the overdrive at the time of releasing the operation of the increase set switch, or an overdrive controller which releases overdrive at the time of operating the resume switch when the vehicle speed at that time is sufficiently lower than the set speed and resumes the overdrive when the vehicle speed has been restored substantially to the set speed. Further, in the cruise control system which is adapted to prevent a decrease in the vehicle speed during hill climbing by releasing and resuming the overdrive, a timer is provided which is reset when the vehicle speed has been reduced and is set when the vehicle speed has been restored substantially to the set speed. Even if the vehicle speed has been restored to the set speed, resumption of the overdrive is retarded by the set time of the timer.