Research And Development For Data-driven PID Controller Based On PLC

At present,the development of intelligent control has been very rapid,but PID control is still accounting for a large proportion in many industrial processes.Tuning PID control parameters,often need to use the experience of experts,but also need to experiment repeatedly,which makes the entire process time-consuming and labor-intensive.Today's industrial control process is more and more complex,followed by a series of problems such as the difficulty of establishing a model and even the failure of the model to be established.With the development of information technology,more and more data are recorded and saved by people in various ways,so data driven theory came into being.Data-driven theory only uses the controlled system's online and offline I/O data to design the controller.At present,in order to realize PID control,PLC manufacturers have developed PID process function blocks or function instructions,which can be called directly and conveniently when users use it.Therefore,this paper is dedicated to the research and development for data-driven PID controller based on PLC.First of all,this paper presents an improved data driven PID controller optimization algorithm.The algorithm uses a clustering method which preferentially determines the clustering center to cluster the collected data.Then on the basis of the euclidean distance,add the angle relationship.According to the current system input information,find the same class and similar groups of information.And then the PID parameter values are obtained according to the local linear model.The validity of this algorithm has been verified in MATLAB.Secondly,this paper introduces the SIEMENS S7-300 programmable logic controller,and uses LAD language and SCL language to compiles and compares the incremental PID controller algorithm.Then the SCL language are chosen to write the algorithm.Finally,this article details how the improved data-driven PID controller optimization algorithm is implemented in the PLC.Its contents include: PLC programming,WinCC configuration screen design and dSPACE real-time simulation platform design.In this paper,the data-driven PID controller optimization algorithm is compiled into a common module embedded in the PLC through the use of SCL language in STEP 7 software,and based on the algorithm to add filtering and speed limit.Then the correctness and practicality of the algorithm are verified through the simulation experiment,which is a closed-loop system composed of S7-300 PLC,dSPACE and WinCC configuration software.