The Uncertain System Is Controlled Based On The Optimal Set Of Disturbance Observers

Coking products are one of the main raw materials for industrial production.The pressure of coke oven gas is an important parameter that affects the output and quality of coke in the process of coking production.At present,many coking plants for coke oven gas pressure control effect is not well.On one hand,it affects the production efficiency and quality.On the other hand,it causes a large amount of gas waste.Therefore,it is of great significance to the study in gas pressure control in the process of coke oven coking.In the actual coke oven system,the controlled system is usually not an ideal system.There are many internal factors such as uncertainty,nonlinearity and time delay as well as various external disturbances in the system,which make the gas pressure in the coke oven unable to reach the target set value.Due to the need of changing of the structure or parameters of the controller,the production line will need to be partially shut down or even rebuilt,which will cause huge economic losses.Therefore,in this paper,a two-level optimal control method based on disturbance observer is studied for several uncertain systems with different disturbances.Firstly,the PID controller is designed in the loop control layer(lower layer),and the controller parameters are obtained through Linear Matrix Inequality(LMI).Then,the disturbance observer is designed in the optimization setting layer(upper layer)to make the output of the controlled system track the target setting value by dynamically adjusting the setting value.Finally,the numerical simulation is carried out.The simulation results show that after the setting value adjustment and optimization,the system output can track the target setting value,and the performance index is stable,which verifies the effectiveness of the method.The contents of this thesis are as follows:1.Aiming at the uncertainty in the coke oven system,a two-level optimal control method is studied for the uncertain system with harmonic disturbance.Firstly,the PID controller is designed and the the parameters are determined through solved.Then,the disturbance observer is designed to estimate the harmonic disturbance.After adjusting the new set value,the system output can track the target set value without changing the controller parameters.2.Aiming at the internal uncertainty and nonlinearity of coke oven system,a two-level optimal control method is studied for the uncertain nonlinear system with the compound disturbance.Firstly,the controller is designed and the the parameters are determined through solved.Then,the disturbance observer is constructed to estimate the harmonic disturbance.Finally,a new compound system is constructed to suppress the norm bounded disturbance by selecting the appropriate setting value,and the system output is stable follow the target setting value.3.Aiming at the internal uncertainty and time-delay of coke oven system,a two-level optimal control method is studied for the uncertain time-delay system with compound harmonic disturbance.Firstly,the controller is designed and the the parameters are determined through solved.Then,the disturbance observer is designed to estimate the disturbance.Finally,the system output is stable by dynamic adjusting the setting value.