THE STUDY AND DESIGN OF LONG DEAD-TIME SYSTEM
Abstract
This paper is based on the long-dead time system. It’s contributed to the system’s and controller design. Attention is also drawn to the controller design of long-dead time system. When the ratio of the dead time and major time constant is little than 0.3, we can use PID controller, we proposed an applied PID design method for the first order plus time delay. But when the ratio is greater than 0.3, or the dead time is too long, the common PID controller is hard to use, then we rely on the Smith predictor. It’s popular. On the base of the existing algorithm, we have added a modified Smith predicator to control the plant with long-dead time. This predictor is more stable and rejected to disturbance. The result of the simulation experiment shows that the mothod is effective.
Key word: long dead-time system ;Smith predicate controller ;PID controller