Automotive control systems for improving fuel consumption

Abstract

An automobile control system is disclosed which saves fuel while reducing environmental pollution. The accelerator pedal of a vehicle is monitored to provide a control signal indicative of the magnitude of the depression of the pedal. A first sensor monitors engine speed, while a second sensor monitors vehicle speed. A comparator aided by mode selected logic automatically selectively compares either the engine speed signal or the vehicle speed signal with the control signal and the throttle is automatically advanced or retarded for a given accelerator pedal position to provide operation with low fuel consumption and improved transmission shifting. In a mode which is particularly economical of fuel consumption for highway driving, the average vehicle speed is controlled by the accelerator pedal and automatically is caused to vary slightly in a cyclical manner so that intervals of acceleration are followed by intervals of coasting in which the throttle is substantially closed. The coasting intervals automatically increase when the drag is low and decrease when the drag is high. The system further simplifies changing from coasting or free wheeling to direct drive by automatically adjusting the engine shaft speed to coincide with the drive shaft speed when engine braking is required.