Adaptive Control for Nonlinear Mechanical Systems

Abstract

In this paper, a model referenced adaptive control system (MRACS) for nonlinear mechanical systems is proposed.
In general, dynamic models of mechanical systems, such as manipulators, are highly nonlinear. This is the reason why control of such systems is difficult. Though the mechanical systems are nonlinear as mentioned above, the form of nonlinear terms in the models can be determined by the structure of the mechanical systems. So we can know the form of nonlinear terms perfectly. Moreover, because of the special feature of mechanical systems, the position, the velocity, and the acceleration of each degree of freedom are measurable.
First, I will show that for such systems, MRACS, which has particular adaptive mechanism and is assured global asymptotic stability, can be constructed, using actively the information of the nonlinearity and the special feature of mechanical systems, without any linearization or approximation. Then I will show the effectiveness of this MRACS using DARM-1 (Direct Drive Arm with two degrees of freedom).