(1) Experimental research method of manual control process of constant temperature and humidity test chamber Select a constant temperature and humidity test chamber http:// as the test object. When the automatic control system is not installed, the manual control operation record is performed by humidification, heating, exhausting, etc. The main contents of the recording are: running time, humidity inside the box, temperature inside the box, exhaust air flow rate, exhaust air speed, ambient temperature. And environmental humidity, etc.
(2) Establishing an adaptive inverse control model The research method summarizes the experimental data, analyzes the results of single-factor and multi-factor experiments, and establishes a mathematical model of temperature and humidity process control through nonlinear fitting. Since the temperature and humidity control process is a complex multivariable, large lag and nonlinear thermal process, linearization decoupling and large lag compensation are needed for the established mathematical model. Only in this way can the control system design be realized. This study intends to use the inverse control method of multivariable nonlinear systems to complete the processing of mathematical models of process control.
(3) Research method for developing constant temperature and humidity test chambers Using the adaptive inverse control model established in the previous section, a constant temperature and humidity test chamber was developed. The equipment is mainly composed of refrigeration system, heating system, dehumidification system, humidification system, water tank and constant temperature. It consists of a main part such as a wet box. The equipment is equipped with PLC and temperature and humidity controller as the automation platform, integrating temperature sensor, humidity sensor, touch screen, solid state relay, etc., to form a constant temperature and humidity test chamber http://electric control system. Using the temperature and humidity sensor to obtain the temperature and humidity induced voltage, directly connected to a temperature and humidity controller, according to the adaptive inverse control model, output a linear voltage of -10V to control the heating system, using PWM control method to control the solid state relay according to Calculate the on-off frequency, adjust the on-time of the humidification system switch, and achieve the purpose of making the temperature and humidity in the box constant.