Two-Degree-of-Freedom H² Output Regulation with Application to Vehicle Motion Control

Vehicle motion control is accomplished through the hierarchy of multiple controls having 2DOF (two-degree- of-freedom) structures. Especially for the actuator control layer, type-0 servo controllers are usually adopted although higher-type servo controllers are capable of tracking faster-varying references. This paper newly develops a design method of 2DOF servo controllers, which attain output regulation and H² performance constraints. The proposed design method enables to easily compute and tune the 2DOF servo controller even if the controlled system is MIMO (multiple-input-multiple-output) and subject to multiple-pole external signals. By utilizing that feature, we design a type-1 servo controller for the motion control of a two-wheeled vehicle, and demonstrate that the type-1 servo controller synthesis outperforms the type-0 controller synthesis.