Comparison of control techniques for a robotic manipulator with base disturbances

A dynamic model of a robotic manipulator mounted on a moving base is derived using the Euler-Lagrange approach to design controllers that compensate for the base movement. It is assumed that the base inertia is large enough not to be influenced by the manipulator motion and therefore the base trajectory can be treated as a time-varying parameter in the dynamic equations. An adaptive controller compensating for the time-varying gravity vector is proposed based on existing schemes. Various controllers are analysed by quantitative comparisons of trajectory tracking performance and high-frequency torque content. The presented derivation is applied to a Mitsubishi PA10-6CE robotic manipulator mounted on a 6-DOF (degrees of freedom) platform.