Pid Parameters Based On Wavelet Transform Self-tuning Multi-mode Temperature Control System

Because there are some shortcomings on tuning the parameters of conventional PID controller, which include the difficulty to make sure the direction of tuning, the possibility to cause the crash of system and the requirement of the system's model parameters, a new self-tuning algorithm of PID based on wavelet is proposed in this paper, which is using some wavelet items to describe the state of system through studying the connection between the step response of system and the wavelet transform of the step response and simulating it by use of Matlab. When this self-tuning method is practically applied in a temperature control system in an electric heater, a multi-mode control algorithm which involves in switching control, fuzzy control and PID control is designed for considering that those control methods have their own advantages and disadvantages.A lot of simulation and the real-time control result show that the methods proposed in this paper is feasible and has good performance.