Research And Design Of A Temperature And Humidity Controller Based On ARM

The main function of the temperature and humidity chamber is to provide a constant temperature and humidity environment for the precision instrument.And using it for aging experiments.The temperature and humidity controller is the core of the temperature and humidity chamber.The function of traditional temperature and humidity controller is simple,and mostly using PID control method.With the development of technology,high precision and high stability are required about temperature and humidity controller,and people require more functions of it.The features of advanced temperature and humidity controller are as follows: using color LCD with touch screen as human-computer interaction interface,with large storage capacity,with high measuring precision of temperature and humidity,with high control precision,providing a lot of auxiliary functions and so on.However temperature and humidity controller in the similar grade or above are seldom produced in our country.This thesis designs an high performance temperature and humidity controller based on ARM,through the analysis of temperature and humidity control technology at home and abroad.This thesis chooses Linux as the embedded operating system,designs the human-computer interaction interface with QT,and uses the neuron PID control strategy to design and realize the temperature and humidity controller.The main works achieved in this thesis are as follows:Firstly,the thesis analyzes the structure of the temperature and humidity chamber and the working principle of each part subsystem.The wet and dry ball method is chosen as the measurement method.This thesis analyzes the principle of dry and wet ball method and measurement error.And the hardware and software method is proposed to reduce the measurement error.Secondly,the thesis analyzes the requirements of temperature and humidity controler and completes hardware circuit design of the controller.Thirdly,the thesis focuses on the intelligent control algorithm to solve the coupling problem and analyzes the characteristics of various intelligent control algorithms by using Matlab simulation.Lastly,the thesis completes software design of the system.The system software includes the acquisition board program,the main control board program and the algorithm program.the thesis focuses on the migration of Linux system and human-computer interaction interface design based on QT.The temperature and humidity controller designed in this thesis has the advantages of high precision,high control precision,good stability,friendly human-computer interaction,low cost.It has widely application value and market prospect.