Study And Application Of Rough Sets Theory In Control System

Rough sets theory is put forward by Poland mathematician Z.Pawlak in 1982, in which an undefined set X can be defined by the lower approximation and the upper approximation. Rough sets theory is a new and effective soft science computring method. It can analyse and deal with not completing knowledge. From then on, its theory and application study have been extensively developed especially in artificial intelligence,pattern recognition,language recognition,automatic control,medical data analysis and various intelligence informations processing field. Rough sets theory offers us a convenient tool to deal with great capacity for liquormagnanimity data produced by current information society. Based on the rough sets theory, Professor SHI Kaiquan extended Z.Pawlak rough sets into singular rough sets, called S-rough sets for short in year 2002. Based on the dynamic transfer of element, S-rough sets is the dynamic set, whose boundary of X in S-rough sets is dynamic. S-rough sets have two forms: one direction S-rough sets, two direction S-rough sets. Z.Pawlak rough set is the special case of S-rough sets and S-rough sets is the general form of Z.Pawlak rough sets. Professor SHI Kaiquan developed the element equivalence class into function equivalence class and advanced function S-rough sets in 2005.The main contributions of this dissertation are as follows:1. Reviewed the developments and research situation of rough sets theory. It explains the basic conception of the rough sets preliminary. Then, the structure and application of rough neural network is given.2. Based on the contents of rough sets theory, S-rough sets theory and variation S-rough sets theory, variation S-probability rough sets is brought up. Its probabilitic properties are put forward to. It application is give in control system.3. Based on the contents of rough sets theory and S-rough sets theory, function S-rough sets is given. Combining with control system, rough-control is brought up based on function S-rough sets. Then, making use of the dynamic transfer of function element, the disturbs of open-loop control system is identified.