Cruise Control Andrew Huisjen

Introduction Invented by Ralph Teetor Invented by Ralph Teetor –Blind Engineer –Didn’t like the way his lawyer drove –Got patent in 1945 Introduced as option on 1958 Chryslers Introduced as option on 1958 Chryslers Now installed on nearly 90% of new cars and truck Now installed on nearly 90% of new cars and truck

System Components Vehicle Speed Sensor Vehicle Speed Sensor Control Computer Control Computer Throttle Actuator Throttle Actuator Cancellation Switches Cancellation Switches Control Buttons Control Buttons

Simplified Physical Model Friction force vs. Engine force Friction force vs. Engine force –Other forces are present in real world situations –This provides a basis for seeing how the principles work

After Laplace Transform and rearrangement: Force Equation Model: Simplified Physical Model

Simulink Models Open Loop Model:

Simulink Models Closed Loop Model:

Simulink Models Closed Loop PID Model: Target Parameters Target Parameters –No overshoot –10-15 seconds to 30 m/s (about 65 mph)

Simulink Models Only P and I are needed to do this well Only P and I are needed to do this well –Desired response is slow –Low values of P and I keep instabilities from being present, so D is not needed P=0.6, I=0.01, D=0 P=0.6, I=0.01, D=0

Simulink Models What if a faster response is desired? What if a faster response is desired? –5-10 seconds, more sporty response –P=0.6, I=0.02, D=0

Real World Much more complicated than my model Much more complicated than my model 1990 Dodge Stealth 1990 Dodge Stealth