Tip position control of flexible arms using a control law partitioning scheme

Tip-position control of a flexible arm with friction in the joints is carried out. The control scheme is based on two nested feedback loops, an inner loop to control the position of the motor and an outer loop that controls the tip position of the flexible arm. The inner loop is controlled by a high-gain controller to remove the effects of friction. A control law partitioning scheme that partitions the control law into a model-based portion and a servo portion is used for the control of the outer loop. To make the arm follow the desired trajectory without any delay, a feedforward term is added to the control law. The control scheme is experimentally evaluated on two very lightweight flexible arms