Unfalsified direct adaptive control of a two-link robot arm

An application of unfalsified control theory to the design of a switching a daptive controller for a non-linear robot manipulator is described. In the unfalsified control approach, candidate controllers are eliminated and disc arded 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 a re non-linear, and have a non-linear 'computed torque' control structure wi th 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 permi ts significantly more precise and rapid parameter adjustments than a conven tional adaptation law having continuous parameter update rules, especially when the manipulator arm is subject to sudden random changes in mass or loa d properties. Copyright (C) 2001 John Wiley & Sons, Ltd.