Joint-space adaptive control of a redundant telerobot manipulator

The design of a joint-space adaptive control-scheme for controlling the slave arm motion of a dual-arm telerobot system developed to study the telerobotic operations in space is presented. Each slave arm of the dual-arm system is a kinematically redundant manipulator with 7 degrees of freedom (DOF). Using the concept of model reference adaptive control (MRAC) and the Lyapunov direct method, the authors derive an adaptation algorithm which adjusts the PD (proportional and derivative) controller gains of the control scheme. The development of the adaptive control scheme assumes that the slave arm motion is noncompliant and slowly varying. The implementation of the derived control scheme does not require the computation of manipulator dynamics which makes the control scheme sufficiently fast for real-time applications. A computer simulation study performed for the 7-DOF slave arm shows that the developed control scheme can efficiently adapt to sudden change in payloads while tracking various test trajectories such as ramps or sinusoids with negligible position errors