Reserch On A Thermostat Of Screen Printing Dryer

Screen printing is widely used in textile printing and dyeing industry.As the last step of screen printing,drying can combine dyes and fibers organically by high temperature treatment in the drying process to ensure that printing does not lose color.As an important control variable in the drying process,temperature plays an important role in product quality.This paper studies a thermostat based on STM32 microcontroller,which can realize multi-channel temperature acquisition and control.The specific contents are as follows:(1)According to the analysis of the practical application scenario of the screen printing drying system on the running platform,the technical requirements are determined.Analyze and design the main framework of the thermostat by dividing it into four modules.(2)The hardware system of the thermostat is established.The circuit mainly includes the minimum system of the microcontroller,the temperature acquisition module,the heating tube driving module,the interaction and communication module,and the power module.The hardware schematic and PCB design of the thermostat are completed.(3)Design the decoupling algorithm for the multivariable system,and on this basis,design the PID decoupling control algorithm and the fuzzy decoupling control algorithm for the thermostat.With control system simulation run on MATLAB software,the function of decoupling control algorithm is verified.By comparing these two algorithms,it is concluded that the fuzzy decoupling control algorithm achieved better dynamic performance of the system.So the fuzzy decoupling control algorithm is selected as the temperature control algorithm of the thermostat.(4)The software of temperature controller is designed,and the digital filtering algorithm is applied to improve the anti-interference ability of temperature measurement system.(5)The temperature controller is debugged and experimented,and the temperature measurement performance of the thermostat is improved by calibrating the temperature measurement system.Experimental results show that the error of temperature measurement of the temperature control range is within 0.5?.Through the temperature control experiment of the drying system,it is concluded that the thermostat realizes ideal outcomes,as temperature control error is within 2?,the temperature uniformity in the double-loop temperature control system also function well,since the temperature difference between the two temperature zones is within 1?.In a word,the multi-input and multi-output thermostat studied in this paper plays a positive role in temperature control and temperature uniformity,as verified in the laboratory dryer.