Reset The Generalized Minimum Variance Self-tuning Pid Control Method And Its Application In Pressure System

Pressure system is one of important control object in the process control, it plays a crucial role in the industry production.However, tradition control algorithm is hard to reach the high standard at present, because pressure system has non-linear character, and its parameter will change with the time and environment. After understanding the relevant research works both in abroad and at home, this essay tries to seek a control method so as to improve the whole performance of the pressure system.Firstly, according to the constitute of the pressure system and mechanism principle, the pressure system’s mathmatical modern was established. Then the parameters of pressure sysem are identified by the least-squares algorithm, and compared with the mathmaticcal modern.Secondly, according to pressure system’s parameter variance and the shortage of anti-interference charactor, minimum variance control algorithm is applied. However, the mathematical modern of the pressure system shows it is a kind of non-minimun phrase system, which can not be controlled by minimum variance control algorithm. Then, the generalized minimum variance algorithm is introdunced.But the generalized minimum variance algorithm also has its own drawback, which is the steady-state error is not zero. Therefore, the generalized minimum variance selftunning algorithm is choosed to control the pressure system. Meanwhile, the system’s stability and the steady-state error had also been analysised, so did the simulation experiment.Then, through the research and experiments of reset algorithm, it is known that this algorithm have the capable of improve the system’s dynamic performance. So the generalized minimum variance self-tuning PID algorithm is presented with the compose of reset algorithm and generalized minimum variance self-tuning algorithm. The simulation experiments in MALTAB show this algorithm has better performance than reset algorithm or generalized minimum variance self-tuning algorithm.Lastly, the pressure control system which based on the ControlLogix platform is designed. Through the communication between the computer and ControlLogix by industrial Ethernet and OPC protocol, MATALB can exchange the data with ControlLogix system, so the calculation results of generalized minimum variance self-tuning reset PID algorithm in MATLAB can send back to ControlLogix system to fulfill the control of the pressure value. The experiments in the pressure system indicate that compared with the generalized minimum variance self-tuning algorithm and normal PID algorithm, generalized minimum variance self-tuning reset PID algorithm can greatly improve the whole pressure system’s overall performance.