Global Stability Control for Nonlinear System in Brushless DC Motor of Machine Tool

In this paper, the nonlinear dynamic behavior of brushless DC motor system of needle machine tool is analyzed by using system phase diagram, bifurcation diagram and Lyapunov exponent spectrum diagram. According to Lyapunov stability theorem and comparison theorem, a global stability controller for brushless DC motor system with and without disturbance is designed. The convergence rate of the controller is controllable and easy to implement in engineering. Simulation results show the effectiveness and good robustness of the controller.