Experimental Control Device Upgrade In A Certain Process

The idea of the subject comes from the purchased experimental devicein the laboratory,which to be found with some shortcomings.The experimental device is to be transformed based on the existing experimental resources in order to carry on experimental teaching in a better way and improve the practical ability of the students.A total of five experimental devices were transformed during the study of the subject.There are three control methods of the experimental device:direct digital control system,PLC control system and distributed control system(DDC,PCS,and DCS);currently,DDC control method has been chosen to carry on the experimentin the undergraduate teaching.The experimental software that comes with thed evicehas no source code,thus,the students cannot see the procedure and the process of the control experiment,which only allow them to operate the experimentin accordance with the contents of the software interface and has reduced students'practical ability.The real-time feedback value of the control valve in the experimental device failed to collect the control system,therefore,in order to improve the experimental system,the control accuracy and reliability,the analog acquisition modulehas been purchased for this transformation,and the transformation of the experimental equipmentwas completed with wiring,debugging,and comparing the before and after performance after the PID experimental transformation.This paper took the experimental device as the main objectand transformed the experimental device from the aspects of hardware,software,algorithm,test and contrast.The main contents of the thesis are as follows:1.A detailed study of an experimental device was carried out to analyze the hardware components of the device,the overall structure of the system,the system testing agencies,the implementing agencies,the auxiliary system and the experimental device control system.And the transformation scheme of the experimental device has been put forward.2.The thesis analyzed the shortcomings of the hardware before transforming,studied the DDC direct control system and the transformed DDC system,and then the electric control valve was wired,debugged as well as analyzed towards its working principle.Secondly,an analog module was added.In the end,the parameters of the modified module were set and debugged.3.The configuration interface and algorithm were designed.First,the paper analyzed the shortcomings of the software before the transformation;then,the configuration experiment interface and the PID controller were designed.Next,the PID algorithm and the PID algorithm of single-volume water tank liquid level were designed.Subsequently,the cascade PID algorithm was designed.After that,this thesis took a comparison of the PID tuning method and chose the most suitable tuning method and tuning procedure for the experimental system.In the end,the algorithm of adding the actual opening value of the electric control valve was designed.4.First of all,a communication test was carried on towardsthe experimental interface of the configuration,and then control valve output and the tracking situation of the actual opening feedback value were analyzed,followed by multiple sets of teststoward the six cases of the PID experiment with the fine tuning;afterwards,the experiment and verification of the dual capacity PID were carried out,which mainly experimentally verifiedfive performance indexes.In the end,the cascade PID was tested and verified.And a comparison experiment was performed between PID with fine-tuning and PID withoutfine-tuning.