The Coupled System Analysis And Fractional Order Controller Design In The Multivariable Process

In industrial control process, most control systems are multiple input multiple output(MIMO)systems, therefore, the research on multivariable control system has much practical significance. Actually, real materials are not always ideal solid or fluid, the structure of which are often between them. The characteristics of controlled system are more accurate to be described with fractional order system. Fractional order pIλDμ controller is a hot issue in industrial control systems. The expectation on stability and robustness of controlled systems increases based on the development of the theory of fractional order PIλDμ control system. The research and analysis on fractional order PIλDμ discrete control of multivariable system is important for the improvement of control performance.The theoretical principle of fractional order calculus is introduced in this paper, including its definition, memory characteristics, transform and frequency response. Value characteristic and numerical solution of fractional order differential equations are discussed. Discretization method of Z domain in the procedure of fractional order calculus is analyzed. Different discrete equations are acquired by using different discrete expansion methods. Five numerical formulas of commonly used discretization method are provided. Parameter adjust method of fractional order PIλDμ controller is analyzed, and the method of fractional order PIλDμ controller based on improved particle swarm algorithm is proposed, the superiority of which is fully performed through simulation and analysis.Aiming at multivariable control system, the characteristics of multivariable coupled system is analyzed, and the decoupled analysis method of multivariable coupled system is deeply researched. Discrete fractional order PIλDμ controller is designed for multivariable systems in industrial process control. The superiority of discrete fractional order controller in multivariable systems is tested and verified to raise the dynamic performance and stability of system, by using improved particle swarm algorithm. The performance standard of multivariable systems controlled by integer PID and fractional order PIλDμ controller is calculated and compared. The control performance of fractional order PIλDμ controller is quantitatively analyzed.In this paper, the research of design method of fractional order PIλDμ controller in multivariable systems, lays the foundation for the design of fractional order PIλDμ controller in multivariable system for industrial production process, which has much significance for the development and application of control theory.