Sliding mode and fuzzy control of toggle mechanism using PM synchronous servomotor drive

The dynamic response of a sliding mode controlled toggle mechanism, which is driven by a permanent magnet (PM) synchronous servomotor, is studied in this paper. The rod and crank of the toggle mechanism are assumed to be rigid. The Hamilton´s principle and Lagrange multiplier methods are applied to formulate the equation of motion. Reducing the differential-algebraic equation and employing the Runge-Kutta numerical method, the state variable representation is obtained. Based on the principles of the sliding mode control, a robust controller is developed to control the position of a slider of the motor-mechanism coupled system. Moreover, a fuzzy logic controller (FLC), which is based on the concept of hitting condition without using the complex mathematical model of the motor-mechanism coupled system, is designed to control the motor-mechanism coupled system for comparison. Numerical and experimental results show that the dynamic behaviour of the proposed controller-motor-mechanism system is robust to parametric variations and external disturbances