END-POINT CONTROL OF A FLEXIBLE ARM KEEPING A CONSTANT DISTANCE TO FLUCTUATING TARGET

In this paper a theoretical and experimental study is presented on the control of a single-link flexible arm, the tip of which keeps a constant distance from the fluctuating surface of the target. The relative displacement between the arm and the target is measured by a gap sensor mounted on the tip of the arm. It is then used, together with the estimated relative velocity, as the basis for applying control torque to the other end of the arm. It is shown both theoretically and experimentally that the PD control using the end-point sensing and base torquing is sufficient to make the flexible arm follow the fluctuation of the target. © 1990.