Adaptive compensation of actuator dynamics in manipulators without joint torque measurement

Neglecting actuator dynamics in control of rigid manipulators can degrade performance and stability of the system. However, consideration of actuator dynamics usually requires measurement of joint torque or armature currents. In this paper, we present an adaptive controller for motion tracking of an n-DOF manipulator without using joint torque measurement. Semi-global convergence of motion and torque tracking errors to zero is proven. We show that the use of non-minimal representation of manipulator dynamics significantly simplifies its linear parametrization. Simulation example shows that avoiding joint torque measurement reduces system sensitivity to sensor failure and noise.