A multi-phase fuzzy variable structure controller with improved transient and steady state response

In this paper, a fuzzy-based variable structure controller (FVSC) is proposed. An adaptive weighting function is used to implement multi-phase strategies of control. In the initial phase, a rapid transient strategy is used and in the final phase, it is switched to a maximum accuracy strategy. It can ameliorate the deficiencies of using only a single look up table. The proposed controller is simple to design and can be implemented cost effectively for both linear and non-linear systems in real time or time critical applications. The design has emphasized on the robustness, fast transient and steady state response with consideration in non-linear system. A well known robot manipulator model is used as an example and simulation results demonstrated that the proposed controller can track the states on the desired switching hyperplane accurately and without any overshoot