The Research Of Nonlinear System Optimal Disturbance Rejection Control

In the actual project, most systems are nonlinear systems, these systems are always affected by various disturbances. Some disturbances are known, can be predicted, there are some other disturbances are unknown, unpredictable. How to make the system to maintain stable operation under strong interference. This paper focus on nonlinear systems and bilinear systems discussed this issue.The main research of this paper can be summarized as follows:Brief introduction to the mathematical model of nonlinear systems and bilinear systems, and introduced very important industry equipment in the chemical production: continuous stirred tank reactor (CSTR). at the same time also describes the disturbance observer, PID controller, optimal control and other related knowledge, the theoretical basis for this paper.For affine nonlinear systems when the external disturbances are known, according to the linear feedforward-feedback optimal control theory, and combined with conventional PID controller, the optimal feedforward-PD based on optimal PD compensation disturbance rejection algorithm is given; when external disturbances are unknown, based on disturbance observer and PID controller, the optimal unknown disturbances rejection algorithm based on disturbance observer and optimal PD compensation is given.For disturbed affine nonlinear systems when the external disturbances are known, according to the nonlinear system feedforward-PD optimal disturbance rejection algorithm.the optimal feedforward-PD disturbances rejection algorithm based on optimal PD compensation is given;when external disturbances are unknown, according to the nonlinear system unknown disturbance rejection algorithm discussed in the under,the bilinear systems unknown disturbance optimal rejection algorithm based on disturbance observer and optimal PD compensation is given.For continuous stirred tank reactor (CSTR) in the industry, in accordance with unknown disturbance rejection algorithm,the simulation study of the practical application of CSTR mathematical model are given,further verify the validity of the algorithm.