Research Of Networked Control Platform Based On WAGO 750-841 PLC

Along with the extension of the control system scale and fast development ofnetwork technology, control systems based on networks are widely applied in themodern industry, which have advantages of less wires, high reliability, goodflexibility and share of information resources, etc. However, since the communicationnetwork has been inserted in the networked control system, some new issues such asnetwork-induced time delay, network scheduling, multiple-packet transmission anddropping network packets appear. Therefore, analysis and design of networkedcontrol system (NCS) has been a hot research problem in the control theory andcontrol engineering field. The key issue of time delay in NCS is studied in thisdissertation.Firstly, some basic background of networked control such as concept,advantages and development are introduced in chapter 1. Also, there presents someissues induced by NCS in this part. Chapter 2 presents the whole process to design aremote control platform based on WAGO PLC in the Institute of Sensor, ErlangenUniversity, Germany. Then, the time delay in NCS is analyzed in chapter 3. Both theelements of the time delay and some methods of pre-compensation are described. Asthe main part of this dissertation, chapter 4 is comprised of some control algorithms.At the same time, this part presents a local closed-loop control to steer clear of timedelay because of the enhancements of Ethemet Fieldbus and PLC technology. Finally,fuzzy PI controller is introduced and actualized on the platform. Some local andremote experiments are made in Erlangen University and Tongji University, whoseresults verify that local closed-loop control system can overcome the disadvantage ofNCS, time delay.The control platform designed in the dissertation runs stably, and localclosed-loop control system is valid, which should be a good reference to relativeresearch.