Research And Development Of Embedded PID Controller Based On Intelligence

PID control is one of the developed firstly control strategies. Up to now, PID control and improved PID control strategies have been widely used in industrial control system for its simple structure and strong robustness. The performance of controllers directly influence the qualities of producing process and products. Therefore, tuning parameters of PID controller is the most important step in the control system design. With the quick development of computer technology and the penetration of intelligence computations in automatic control field, they support new ways and approaches for tuning parameters of PID controller.Fuzzy control simulates the human thinking, which is able to deal with the imprecise and nonlinear information in the objective world. At the same time, it possesses the ability of anti-jamming. In this thesis, fuzzy control is used to produce the change of parameters of PID controller, which makes PID controller self-adaptive and robust. On the basis of the basic PID control, GA algorithm, AI algorithm and PSO algorithm, which are from the intelligent behavior of the natural beings, are applied to tuning parameters of PID controller. The related theory analysis and convergence proof are done. From the results of PID controller, it is not necessary to be continuous and differentiable for the function of control object. Moreover, the effect of tuning parameters is satisfied, which is independent of the initial values of PID controller.Based on tuning parameters of the improved PSO algorithm, the embedded self-tuning PID controller is designed. In the hardware, the master control chip is S3C44B0X, which has 8 channel 10-bit A/D converter, the LCD controller and double power supply. Because of no on-chip RAM and ROM, 8MB SDRAM and 2MB NOR Flash ROM are expanded. In the interface of man and machine, the touch screen of 320x240 is adopted. In the software, the process of transplanting the embedded real-time operating system, namely uC/OS-II, on S3C44B0X is introduced in detail. Based on uC/OS-II, realize the self-tuning algorithm of PID parameters by dividing the application into several tasks with modularization.