Control of flexible joint robot system by backstepping design approach

The adaptive backstepping design approach to the control of flexible joint robot manipulators is presented. When the system parameters are known, the backstepping design method is directly applicable to control flexible joint robot manipulators with state feedback. On the other hand, when the system parameters are unknown,the original adaptive backstepping design method requires knowledge of joint accelerations that are prone to noise in order to control flexible joint robot manipulators. In order to overcome the problem, we present an additional robust control law in conjunction with the adaptive backstepping design procedure. Compared with most of the available control schemes for flexible joint robot system that assume weak joint flexibility or knowledge of joint accelerations, the proposed control law guarantees global stability of the robot manipulators with uncertain joint flexibility without recourse to any joint acceleration or jerk measurements.