A Nonlinear Control Algorithm Design Method Applying State-Space Linearization

An efficient method to design nonlinear control algorithm for robot manipulator controllers, based on state-space linearization concept, is presented. The method consists of three steps ; (1) abbreviated equations which approximate the dynamic equations of a manipulator are calculated by Fourier transformation, (2) using the simplified equations, linear dynamic equations which are the first order approximations of the equations at an operational point, are derived, (3) nonlinear compensations are designed so that exact linearization of the manipulator's dynamic equations are achieved. The method was applied to a controller design for a direct drive manipulator. The control ability of the system was verified through digital simulations and some experimental results.