Analytic nonlinear H-infinity inverse-optimal control for Euler-Lagrange system

Abstract

Recent success in nonlinear H-infinity control design is applied to the control of Euler-Lagrange systems. It is known that the existence of H-infinity optimal control depends on solvability of the so-called Hamilton-Jacobi-Isaccs (HJI) partial differential equation. In this article, the associated HJI equation for nonlinear H-infinity inverse-optimal control problem for Euler-Lagrangian system is solved analytically. The resulting control is referred to as the reference error feedback, which takes conventional PID controller form. Consequently, robust motion control can be designed for robot manipulators using L-2-gain attenuation from exogenous disturbance and parametric error.