Temperature And Humidity Controlled Environmental Chamber Based On The Genetic

Environmental chambers provide a stable test environment for testing the formaldehyde, VOC and other harmful gas. The temperature and humidity in the environmental chambers are two important factors that affect the measurement results, therefore, according to the unified national testing standards, we must control the temperature and humidity within a certain range in order to measure the content of harmful gases more accurate.This paper studied the temperature and humidity control system of a certain product quality supervision and Inspection Institute of multi-parameter environmental chamber and established the model of the cabin environment, proposed a smart intelligent control strategy.Firstly, we analyzed the status of research on the cabin temperature humidity control environment at home and abroad and developed the model of environment cabin temperature and humidity with the step response method. Based on actual measured data, we established environment chamber mathematical models with the two-point.Secondly, due to environmental temperature and humidity of the cabin has a coupling, in order to achieve better control of temperature and humidity, we design a compensation to decouple link between temperature and humidity. According to mathematical model of the temperature and humidity in the environment cabin which we have built and the coupling relationship between the temperature and humidity, feed forward compensation link control system of temperature and humidity in the environment cabin, decoupling temperature and humidity in an environmental chamber, simulate the temperature and humidity decoupling in the environment cabin by MATLAB simulation. The results show that, for a given constant conditions, the feed forward compensation decoupling control effect is better than no compensation.Again, due to the environmental chamber in different test samples, with different test conditions also showed non-linear characteristic, for feed-forward compensation decoupling only a single test sample, and although the traditional PID control is simple and convenient, it also cannot obtain the good result in the constant test conditions. In this paper, we use a combination of genetic algorithm and PID control model to control the temperature and humidity in the environmental chamber, taking into account the practical engineering application characteristics of environmentalchamber, ignoring changes in temperature and humidity shadow, using only temperature compensated humidity control mode, solves the problem of environmental control cabin well. The simulation show that GA-PID control under different test conditions, both the control precision and stability are achieved better control effect than the traditional PID control, and then indicate that use GA-PID control strategy of environment chambers to test the accuracy of the samples has better adaptability.