Improved Sliding Mode Controller for a Nonlinear Inverted Pendulum System

The present paper studies on a novel Hybrid Adaptive Controller which adapt its parameters online with change of nonlinear physical parameters for an under actuated Inverted Pendulum System. For this purpose, first the nonlinear equation is transformed into linear types by using feedback linearization method and then because of nonlinear nature of output states, the adaptive robust sliding mode control was applied based on adaptive mechanism to update the controller parameters according to the Gradient Descent Method and the chain rule of differentiation. In the following, to remove chattering and cancellation of sudden input changes, feedback linearization technique based on optimized coefficients was combined with the hybrid adaptive robust Sliding Mode Controller and then, multi-objective optimization was used to extract the optimal control parameters. The results and analysis demonstrated the ability of the proposed controller in terms of stability, minimum tracking error and optimal control input in confronting other two controllers.

Keywords:

Inverted Pendulum System , Hybrid Adaptive Controller , Gradient Descent Method , Sliding Mode Controller.