Two-Time Scale Stabilization of a Flexible Arm With Output Feedback

This paper presents an approach to designing a control system with output feedback for a lightweight flexible arm. A two-time scale dynamic model is obtained, which allows the adoption of a composite control strategy. First a slow control can be designed for the slow (rigid) subsystem, then a fast stabilising control for the fast (flexible) subsystem. The problem of the lack of full state measurements concerned with the fast control design is solved. An output feedback low order dynamic compensator is designed, whose optimal gains are computed via a convergent numerical algorithm. Also, a more robust design can be achieved if a loop transfer recovery procedure is introduced. The design procedure is finally tested by means of nonlinear simulation results for the flexible arm.