active suspension

state feedback

class nonlinear

control laws

feedback control

control chaotic

International Journal of Systems Science

The state-space approaches have stayed in an absolutely dominant position in the field of systems and control for over a half century. Although a state-space representation is more suitable for deriving the state-response solution and observation (estimation), it does not provide as much convenience as desired for the control problem. In this paper, the concept of high-order fully actuated (HOFA) systems is firstly revisited, and it is pointed out that HOFA systems serve really as models for control systems rather than representing a small portion of physical control systems. Based on the HOFA model, a basic procedure is proposed for control of nonlinear systems satisfying certain conditions, whose first step converts the nonlinear systems into a pseudo strict-feedback system, and the second step establishes the HOFA model of the system. Once an HOFA model is derived, a controller can be immediately designed to make the closed-loop system a constant linear one with a desired eigenstructure. All the design degrees of freedom existing in the closed-loop system are also provided, which can be further utilised to achieve additional system performance. An example demonstrates the design procedure and shows the effect of the proposed HOFA approach.

High-order fully actuated system approaches: Part I. Models and basic procedure