Three Tank Water Level Control System, Dynamic Simulation And Multivariate Process Monitoring

With the development of manufacturing level and science technique, the automatic control systems get more and more complicated and systematic; there is an increasing demand for high safety, reliability and validity for equipments and plants. To maintain the safety and effectivity in industry process and enhance the quality of product, on-line process monitoring and awareness of manufacture running status in time have become major topic in the field of process control presently.The laboratorial apparatus of three-tank water level control system is a scientific research product, which allows study of the principles of process control as the process variables, for example the level and flux, to be measured, controlled and observed for its variability during the simulation process of modern industrial manufacture. It has the common characteristic of dynamic process in process control such as great inertia, larger delay, nonlinear and difficult to be controlled precisely, so that it becomes a perfect experimental platform in the field of control theory and control engineering, process control teaching, testing and study. Consequently, three-tank water level control system has received wide attention in the monitoring and fault diagnosis algorithms of coupled nonlinear systems. Based on this system, using MATLAB dynamic process was simulated and it realized the on-line monitoring of multivariate process by using control software platform.First, this thesis analyzed the manufacture process, static and dynamic characteristics of three-tank water level control system. The model and simulation of three-tank water level control system is implemented by using of MATLAB simulation tool to measure level value, and control flux of valves, analyze the variations of the flux in connected pipes. Further, the three-tank water level control system is simulated in the cartoon display with S function in MATLAB, which is more intuitionistic and realistic. The friendly graphical user interface was designed using M-file of MATLAB, which is more convenient and exact to setting, displaying and tracking related parameters.Another, based on the three-tank water level control system, simulation researchon the fault diagnosis is carried out. Firstly the nonlinear model of three-tank water level control system is linearized at a certain operating point, and then a fault detection filter (FDF) is designed. Simulation research on the detection of fault that is probably appeared around the system operating point in sensors is carried out. The simulation results illustrate that the FDF detected the faults occurred in different sensors effectively.Finally, the thesis designed and developed the software platform of three-tank water level control system using the programming tool of Visual C++6.0.It includes not only the person-machine interface and the integral separation PID control algorithm, but also the real-time data acquisition, the real-time data restore, the historical data consulting and the control parameters setting etc.. It realized the on-line monitoring of multivariate process in the same time.