Unfalsified direct adaptive control of a two‐link robot arm

Abstract

Abstract An application of unfalsified control theory to the design of a switching adaptive controller for a non‐linear robot manipulator is described. In the unfalsified control approach, candidate controllers are eliminated and discarded when their ability to meet performance goals is falsified by evolving experimental data. Switching occurs when the currently active control law is among those falsified. In this design study, the candidate controllers are non‐linear, and have a non‐linear ‘computed torque’ control structure with four switchable parameters corresponding to unknown masses, inertias and other dynamical coefficients of a class of ideal, but imperfect robot arm models. Simulations confirm that our unfalsified switching controller permits significantly more precise and rapid parameter adjustments than a conventional adaptation law having continuous parameter update rules, especially when the manipulator arm is subject to sudden random changes in mass or load properties. Copyright © 2001 John Wiley & Sons, Ltd.