The Development Of The Control Software Of The Wall-mounted Gas Boiler Based On The Adaptive PID Control

The wall-mounted gas boiler is a multifunctional household electric appliance which can satisfy people's demand for a comfortable and convenient life by providing heating and domestic hot water. With the rapid development of China's economy and the increasing elevation of Chinese people's living standards, wall-mounted gas boilers have been more and more widely used in people's daily life.First of all, this thesis offers an introduction to the internal structure and working principles of the wall-mounted gas boiler, as well as the software and hardware of its control system. And particularly, it makes an in-depth analysis of the continuously variable power control module in the control circuit over the rotation speed of the draught fan.Secondly, this thesis makes a thorough study of the phisycal models and control features of the draught fan and the gas proportional valve of the wall-mounted gas boiler. And it, through a large amount of experiments, defines the connections between the rotation speed of the draught fan as well as the turning angle of the gas proportional valve and the duty ratio of the PWM wave, and thus provides a theoretical basis for the accurate output of the control system.During the control of the water temperature of the wall-mounted gas boiler, the manipulated object has such features as dead time, nonlinearity and time varying. Besides, the model parameter of the manipulated object or the model itself will change due to various external interferences. In view of the condition that the model of the manipulated object will change with various external interferences, the thesis puts forward a control method based on the adaptive PID control algorithm, gives a detailed account of the implementation process of the algorithm, and focuses on the discussion of the programming of the pole placement self-tuning PID control system of the wall-mounted gas boiler.And finally, this thesis, based on the pole placement self-tuning PID control principle, defines the parameter of the PID control system, establishes the simulation model of the system, and confirmes the feasibility of the algorithm. It also devises the master control program flow of the system and writes the master control program.