Cruise control is to maintain a car's speed at a certain number during long drives. The system is designed so that the throttle is electronically controlled to adjust and respond to the load demand. As the car cruises along a gentle climbing road, the throttle should open up to maintain speed. Inversely, as the road gently slopes down, cruise control will close the throttle to still maintain set speed. The key is proportional throttle control as well as closed loop speed sensing.
I happen to own an old truck with a manual throttle control as shown below. For this project, this manual throttle control is the perfect candidate for automation.
To make it work:
1. High torque servo motor drive mechanism
2. Hall effect speed sensing
3. Lots of speed calibration values
4. Mechanical system to link the throttle to the control servo
5. Stepping on the brakes to immediately disengage the system
For safety, the project will not tamper with existing electrical circuits and mechanical systems but will be a full piggy back system. The servo mechanical drive will be fully override capable in case of abnormal behavior. Power failure will also put all mechanisms back to manual default.
Completion by end Q2, 2013
Ideas are welcome if contributed for free. :-)