Application of Ideal Bode Transfer Function Tuning Fractional Order PID in Pressure Difference of Vertical Mill

Summing the grinding process of cement vertical mill, this paper analyzes the technology of this process, points out the key controlled variable in the process - the vertical mill pressure difference, and establishes the model. In this paper, the vertical mill pressure difference is controlled by fractional order PID controller, which is based on the parameter optimization method with ideal bode transfer function as the reference model, because of its insensitivity to gain variation. As the integral order λ and differential μ are also adjustable, parameter optimization is more complex ,a modified differential evolution algorithm is adopted to speed up the optimization. The simulation results show that the control performance of fractional order PID controller is better than that of integer order controller, and the optimization speed of modified differential evolution algorithm is also improved.