Full and reduced order IMC anti-windup compensators for a class of nonlinear systems with application to wave energy converter control

Two IMC-type anti-windup compensators are proposed for a class of nonlinear systems under partial nonlinear dynamic inversion control. The class of systems under consideration is assumed to be globally quadratically stable, but some of the nonlinear terms are assumed not to belong to the range space of the input distribution matrix. One of the IMC compensators is a natural generalisation of a linear IMC compensator, but it is also shown that a globally stabilising reduced order compensator, of a similar structure to the first, exists for this class of plants. The two anti-windup compensators are applied to a wave energy converter control system, the dynamics of which fall into the class of nonlinear systems studied here. Preliminary results show that the two IMC-type anti-windup compensators perform well on this case study.