The Application Of Nine-point Controller In The Liquid Level Control System And Performance Analysis

Liquid level control is one of common control system in industrial process.Liquid level control system have many characteristics such as nonlinearity,time lag,inertia and so on.Today the conventional control methods are sometimes difficult to meet the control requirements.In the process of control there would be a long tine to adjust the control system and a large overshoot.In this paper, we meet the requirements of liquid level remote control in a certain mining area reservoir in Xinjiang.The current frontier controller technology, nine-point controller technology,is applied to single loop control system to overcome the above shortcomings.After reviewing the literature,there is few articles about the employment of the nine-point controller in the liquid level control.Therefore, how to implement the technology is the key to solve the problem.In this paper, we discuss and research the implementation of the nine-point controller in liquid level control system and analysis its control performance.As a new kind of intelligent controller,it is put forward on the basis of the fuzzy control theory and logical control theory.Its basic controlling thoughts is that we get the system allowed range of error and allowed range of error change rate through the analysis of the system.And then the running status of system can be divided into nine regions with the use of range of error and error change rate. According to the properties of these controlled objects`curve we apply proportional control function respectively in order to get the control effect which meet the requirements of controlling.The controller does not need to predict the accurate mathematical model of controlled object.It has the characteristics of simple structure, strong adaptability.After that,I use the MATLAB software to research and optimize the performance of control system.The final conclusion is that control performance of the system has greatly been improved than the original single loop PID control, and through the simulation the instructional conclusions are given for the following commissioning of the system and the tuning parameters of controllers.In this thesis,take the liquid level in a impoundment area of a certain mining area as the control object.Zijin bridge configuration software, is used to study the application of nine-point controller in liquid level control system.According to the result of field inspection, choose the suitable equipments for field modification.Join the AGPRS1081 wireless data acquisition module into the control system,to make the wireless communication realized between the central control room and the control of the scene.In the process, mainly solves the communication problems such as real-time data cannot be stored in time.