Design And Achievement Of Automatic Control System Of Air Clean Test Platform

In order to achieve the purpose of verifying that the space station’s traceharmful gases purification system and regenerative CO2removal systemfunction,we need to design and implement an air clean test platform. This paper hasanalysed the function of air clean test platform and successfully designed theautomatic control system for it, the automatic control system has achieved a24-hourstable operation.First of all, This paper analyses the function of air clean test platform, thendesigns the overall program of the control system according to the analysis. Theautomatic control system consists of three levels: the host computer layer, the lowermachine layer, the field sensors and actuators layer. This paper selects AdvantechIPC as the host computer to achieve the control system’s monitoring interface basedon the LABVIEW development platform; selects Siemens S7-300seriesprogrammable logic controller(PLC) for the lower machine to achieve the mainlycontrol logic and adjusting of temperature and humidity based on the STEP7development platform. The host computer communicates with the lower machinethrough3964(R) serial communication protocol.Secondly, To achieve the concrete realization of the control system, in thispaper, the system’s hardware implementation and software implementation aredesigned in detail: the hardware design includes the selection of PLC modules andthe designing of control system’s electric circuit; the software design includes thehost computer software design and the lower machine software design.Thirdly, take advantage of PLC’s Logic control functions, this paper designsand achieves the system’s automatic control logic and manual control logic in thelower machine. For the adjusting of temperature and humidity has delaycharacteristics, this paper uses the PID control algorithm with delay compensationin the humidity controlling and uses the cascade PID control algorithm with delaycompensation in the temperature controlling, based on PLC.The automatic control system which designed in this paper has been running astability test.Now the automatic control system has been put into daily use, runningwell. At last, this paper gives the operating status of the system a brief introductionand analyses the temperature and humidity’s controlling results. The temperatureand humidity’s control accuracy meets the design objectives well.