Application of a modified error governor to electronic throttle control

The control of an electronic throttle in an automotive vehicle is considered in this paper. Due to a saturation non-linearity in the control loop, a nominal controller produces undesired windup effects. Because of mechanical restrictions, especially windup-induced overshoots of the throttle plate angle should be prevented. Well-known anti-windup methods, like back-calculation, can only be effectively used with PID controllers. Since the nominal controller is not of PID-type, an Error Governor (EG) is used to prevent windup. Additionally the original EG is modified to meet special characteristics of throttle control. One modification is to handle a non-linear feedforward part that is used to compensate for friction of the throttle plate. And a second adjustment concerns time-variant saturation limits that occur due to voltage fluctuations of the car's battery. The suggested method is tested on a throttle test bench.