Controller for multidegree of freedom nonlinear mechanical system

A controller for a multidegree of freedom nonlinear mechanical system which carries out adaptive model following control for a nonlinear mechanical system with multiple degrees of freedom that can be described by a q-th degree differential equation and with driving sources for each of its degree of freedom, comprising:

• (a) a model section having a built-in reference model that has predetermined response characteristics;
• (b) a first synthesizing means for obtaining the difference of the internal states between the mechanical system and the reference model;
• (c) means for detecting signals for the position and i-th derivative (1.ltoreq.i.ltoreq.q) of the mechanical system;
• (d) an adaptor for determining the time-varying parameters of the mechanical system, in accordance with the difference in the internal states between the mechanical system and the reference model obtained from said synthesizing means, an input applied to a control system, the signals for the position and i-th derivative (1.ltoreq.i.ltoreq.q) of the mechanical system, and a nonlinear structure of the mechanical system;
• (e) computing means for computing a compensating input to cancel the nonlinear forces in the mechanical system and the interferential forces between the degrees of freedom of the mechanical system, in accordance with the determined parameter signals obtained from said adaptor, the signals for the position and i-th derivative (1.ltoreq.i.ltoreq.q) of the mechanical system, and the nonlinear structure of the mechanical system;
• and
• (f) a second synthesizing means for synthesizing the compensating input from said computing means and the input that is applied to the control system in order that the output of the mechanical system corresponds to the output of the reference model in the course of time.