Joo-Han Park
The Journal of Mechanical Science and Technology, vol. 23, no. 4, pp.1008-1011, 2009

Abstract : In the flexible manipulator control, tip-tracking control of flexible manipulator results in non-colocated control problem, which has a non-minimum phase dynamic characteristic. The level of tip-tracking performance in the noncolocated control system depends on the characteristics of the tip reference trajectory to be followed, as well as on the characteristics of the flexible manipulator system itself. In a previous research the use of a tip reference trajectory, filtered by a properly designed time-delay command shaping filter, has been proposed and a multirate repetitive learning control (MRLC) has been used as the tip-tracking controller. The practical implementation of this approach, however, requires estimation of the tip position, which is not easy to obtain. In this paper, a practical implementation of the approach is considered and the tip position is estimated with a fourth-order Kalman filter. The experimental results show that, with the use of Kalman filter, the proposed scheme results in a drastic reduction in residual tip vibrations and the required actuation effort.

Keyword : Flexible manipulator; Tip-tracking control; Command shaping filter; Tip position estimation; Learning controller