Global output-feedback tracking and load disturbance rejection for electrically-driven robotic manipulators with uncertain dynamics

In this paper the tracking problem for rigid robot manipulators with uncertain parameters and unmodelled torque actuators (DC motors) is addressed and solved by combined first/second-order sliding mode control methodology. The robot is electrically-driven through a pulse-width modulated actuator supply voltage. The proposed controller does not require the availability of the joint velocity, is insensitive to smooth load disturbances and guarantees a global domain of attraction. Computer simulations confirm the feasibility of the proposed approach.