Abstract: A speed control system maintains vehicle speed at a desired speed by controlling the engine throttle. The speed control system includes feedback from a quadratic control signal having an amplitude related to a square of the speed error signal and also having the speed error signal's sign. The speed control system also includes integral feedback control and proportional feedback control.

Abstract: A speed control system having an operator actuable switch assembly providing a single multiplexed output. Decoding of a single momentary switch generates a standby mode when the speed control system is in the control mode, and generates a resume mode when the speed control system is in the standby mode. The decoding also provides the speed control system with the appropriate operator actuable commands only after all switches of the switch assembly are concurrently detected in a neutral or idle position.

Abstract: A speed controller maintains the engine throttle at a desired throttle position based upon an initial throttle position and a speed error signal. The initial throttle position is generated by multiplying vehicle speed by a constant and adding an offset value related to throttle position at idle and speed control slack. The initial throttle position is adaptively updated by subtracting the above product from actual throttle position during speed control operation to learn a new offset value.

Abstract: A speed control system electronically controls the engine throttle to maintain vehicle speed at a reference speed in response to a control signal. The control signal is generated by multiplying a speed error signal by a gain value. Such gain value is provided with a variable amplitude having a first linear relationship to the error signal which is increased to a second linear relationship having greater sensitivity when the error signal exceeds a preselected amplitude.

Abstract: A speed control system controls the engine throttle to maintain vehicle speed at a desired speed and increments the desired speed to a previous reference speed during resume mode of operation or other speed alteration mode of operation. A control signal is generated which is related to both the difference between actual vehicle speed and desired speed. The control signal is multiplied by a gain value generated with a first amplitude when the vehicle speed is within a preselected range from the reference speed, a second amplitude when the vehicle speed is within the preselected range, and a third amplitude when the vehicle speed is greater than a desired speed. An actuator controls the engine throttle in response to the product of the error signal times the gain value for asymptotically approaching the previous reference speed.

Abstract: A vehicle speed control system having speed altering modes such as acceleration and resume modes. When resuming speed control operation to attain a previously set desired speed, a lower reference ramp and upper reference ramp are generated in a preprogrammed manner. The lower reference ramp is selected as the reference speed when vehicle speed is below such ramp, and the upper reference ramp is selected as the reference speed when the vehicle speed is greater than such ramp. The vehicle speed is selected as the reference speed when it is within both reference ramps.

Abstract: A speed control system operable during the resume mode which initially turns the engine throttle to an initial throttle position computed as a function of vehicle speed. A reference ramp is then incremented towards the previously set or resume speed and the throttle controlled in response to a speed error between reference and vehicle speed. When incrementing of the reference speed is terminated, the engine throttle is turned to a recomputed throttle position based upon the previously set speed.