Dynamic surface controller for flexible joint robots without velocity measurements

This paper proposes an dynamic surface control approach for flexible-joint (FJ) robots without velocity measurements. We develop a link position tracking controller using the observer dynamic surface design procedure. From the controller design procedure, we show that the proposed controller can be simpler than the observer backstepping controller. It is proved that all signals in a closed-loop system are uniformly ultimately bounded from the Lyapunov stability analysis. Finally, the simulation of a three-link FJ robot are performed to verify the effectiveness of the proposed control scheme.