Model based sliding manifold design for a class of nonlinear systems

Abstract

This paper proposes a new sliding mode control design based on a choice of nonlinear sliding manifolds for second order mechanical systems that can be formalized into that of robotic manipulators. While typical sliding mode control presents a model compensation term in its control law, the new approach shows that by designing model based sliding manifolds, the resultant torque control law expression is considerably simplified and ultimately becomes linear in terms of the joint angles and rates. This approach allows additionally decoupling of the chattering effect on the torque inputs on each axis. A new property related the gravity term is introduced and is used for stability analysis purposes. Simulation results compare the introduced approach to the conventional linear manifold design. The results demonstrate that the new approach reduces transient constraints on torque input.