ABSTRACT
Control design concerns how to improve the performance without changing the system to be controlled. The term performance is used to summarize several aspects of the dynamic behavior, such as transient period, oscillatory and overshoot behavior during the transient state, steady-state errors as well as the robustness versus parameter variations and disturbance inputs. Transient response is the system response in time domain while a transient state occurs. The transient state takes place when the motion characteristics change in response to system inputs or external disturbances, such as external forces acting on the vehicle, steering angle change. Control design for acceptable steady-state errors can be thought of as placing a lower bound on the very-low-frequency portion of the system. The steering ratio refers to the change of steering wheel angle at a given steady-state steering wheel position, with respect to the change of steer angle.
