PID Controller Tuning Based On Relay-feedback Test

With the development of industrial technology, PID tuner, which appeared in 1930s, was accepted for its better control performance than direct-action tuner. Because of simple structure and strong robustness, PID controllers and trans-formative PID controllers have been widely used in industrial control systems. The capability of controller directly influences the qualities of producing process and products. Therefore, parameter tuning of controllers is the most important step during system design. With the development of computer technology and artificial intelligence in automatic control field, auto-tuning PID controllers began to be used in recent years.Parameters of PID controllers can be obtained with various algorithms. Excellent control algorithms are astringent, intuitionistic and simple. Load disturbance and set-point variety also need to be considered.This thesis studies various methods of parameter auto-tuning...