Effect of the joint inertia on selection of under-actuated control algorithm for flexible-link manipulators

In this paper, two control techniques, namely computed torque law and composite control based on the singular perturbation approach, are used to control the motion of a flexible-link manipulator. The effect of manipulator joint inertia on the selection of the control technique used has been investigated. It is found that, unlike composite control, the joint inertia increases the oscillations of the flexible arm when the arm is commanded to follow a certain trajectory under the computed torque control law alone. On the other hand, when we exclude the joint inertias, while modeling the flexible arm, there is no significant difference between the system response based on singular perturbation approach and that based on the computed torque method.