Research On Measurement And Control Technology Of Multi-stage Vacuum Dry Pump Performance Test Platform

With the development of industry,the vacuum pump industry has developed rapidly,and vacuum pumps are widely used in petrochemical,semiconductor,photovoltaic,aerospace and other fields.Due to the slow start of vacuum pump technology in China and the relatively large market demand,the main market in China is still occupied by imported vacuum pumps.In order to enhance the competitiveness of domestic vacuum pumps,the state has vigorously supported vacuum pump manufacturers,and the company itself has increased its investment in research and development technology.At present,China’s vacuum pumps have initially recovered some markets,but they still lack quality advantages compared to imported pumps.At present,China’s vacuum pump testing technology is not developed.The vacuum pump test bench has low precision,low automation and single function.To solve this problem,the research team designed a multi-stage vacuum dry pump test bench to detect multi-stage pump or single-stage pump pumping.Gas performance,providing data support for vacuum pump design.This article first introduces the basic structure and operating process of the test bench and analyzes the control requirements of the test bench.According to the control requirements,the control structures of the systems are compared and the final control scheme is determined.The method of using a combination of Programmable Logic Controller(PLC)and industrial computer to complete the system Measurement and control function.Then draw the system’s signal point statistics table and electrical schematic diagram according to the signal conditions of the hardware sensors on the test bench,and select the PLC brand model according to the type and number of signal points.After the system structure design is completed,determine the data flow direction of the system and conFig.the position of the signal points,which is convenient for later debugging and system maintenance.Design the communication method of the system according to the electrical hardware and signal flow,and introduce the implementation of the system’s measured and controlled functions.In response to the temperature control requirements of the front-stage vacuum chamber,neural network PID controllers and classic PID controllers are designed.The two controllers are used to perform step-signal tracking simulation on the first-order nonlinear model and the second-order linear model.Establish a heating model for the test bench,and use two controllers to simulate the heating model.According to the simulation results and the actual situation,PID temperature control algorithm is used to control the temperature of the front vacuum chamber of the test bench.Finally,in order to grasp the running status of the system clearly and timely,a human-machine interface was developed on the host computer using force control configuration software,and the script was compiled using C language.The man-machine interface can realize the functions of system monitoring and data collection and storage.The monitoring function is realized by developing the system operation monitoring interface.In addition,the real-time data trend monitoring function and historical data query printing function are also developed.A database was developed using configuration software,and the data was saved as data samples.The actual operation status of the multi-stage vacuum dry pump performance test platform shows that the system runs stably,responds fast,and has strong anti-interference ability,which basically meets the control requirements.The operator can realize the monitoring function and command output function through the man-machine interface.The database collects and saves data samples to provide data support for the development of vacuum pumps.