Abstract
The rough set theory (RST) is an important soft computing method. Some useful knowledge can be extracted from original data with it. In this paper, a design method for rough controller (RC) is proposed based on RST, and it be used to control the water-levels of a three-tank system. The key element to design RC is how to extract rule sets from human control behavior data according to RST algorithm. The three-tank system consists of two variable frequency controllers (VFC), two ac-motors, two pumps and three tanks. The RC design steps include sampling control behavior data from a human operator for controlling the levels of the tanks, constructing the primal decision information table (DIT) using these data, extracting the control rules from these tables, completizating the rule sets, designing the controller and checking rules. Finally, the RC are used to control the actual system. The experimental results indicate that design method of the RC is feasible and control effect is satisfying.