ADAPTIVE REGULATION OF MANIPULATORS USING ONLY POSITION MEASUREMENTS

This article considers the motion-control problem for uncertain robot manipulators in the case where only joint-position measurements are av ailable, and proposes an adaptive controller as a solution to this pro blem. The proposed control strategy is general and computationally eff icient, requires very little information regarding the manipulator mod el ol the payload, and ensures that the position-regulation err or pos sesses desirable convergence properties: semiglobal asymptotic converg ence if no external disturbances are present, and semiglobal convergen ce to an arbitrarily small neighborhood of zero in the presence of bou nded disturbances. It is shown that the adaptive controller can be mod ified to provide accurate trajectory tracking control through the intr oduction of feedforward elements in the control law. The adaptive regu lation and tracking schemes have been implemented in laboratory experi ments with an IMI Zebra Zero manipulator: These experiments demonstrat e that accurate and robust motion control carl be achieved by using th e proposed approach.