Fuzzy SMC Based on Power Reaching Law with Variable Universe for Servo System

To decrease the influence of friction on control accuracy of electro-optical tracking servo system, the fuzzy sliding mode control (SMC) with variable universe was put forward. Firstly, based on the LuGre friction model, a sliding mode controller with power reaching law was set up, Then, to relieve the chattering problem, the fuzzy method with variable universe was used to adjust the plus of the sliding mode controller, Finally, the simulation experiment was put up to compare control accuracy of these two controllers. The simulation results show that the fuzzy sliding mode controller with variable universe not only improves the tracking accuracy, but also relieves the chattering problem substantially.