智能控制课件-第4章模糊控制系统.ppt

4.2.2 Rule Base（规则库） The description of rule base Rule base is composed of several control rules, these rules are summed by expert experience, denoted as: IF …is …AND …is …THEN …is…. R1 : IF E is A1 AND EC is B1 THEN U is C1 R2 : IF E is A2 AND EC is B2 THEN U is C2 ……………………………………………………… Rn : IF E is An AND EC is Bn THEN U is Cn Here, E and EC denote the input language variable “error” and “error rate” ; U denote the output language variable “control quantity”. Ai , Bi and Ci is the corresponding language value of E,EC and U in the ith rule. 4.2 The structure and design of fuzzy controller 4.2 The structure and design of fuzzy controller Rule base can also be described by a matrix U EC NB NM NS Z PS PM PB E NB NB NB NB NB NM Z Z NM NB NB NB NB NM Z Z NS NM NM NM NM Z PS PS Z NM NM NS Z PS PM PM PS NS NS Z PM PM PM PM PM Z Z PM PB PB PB PB PB Z Z PM PB PB PB PB 例如在模糊控制直流电机调速系统中，模糊控制器的输入为E（转速误差）、EC（转速误差变化率），输出为U（电机的力矩电流值）。 Define 7 language-subsets on domain of E,EC,U： {PB,PM,PS,ZO,NS,NM,NB} After analysis and summary for each possible value of E and EC, the control rules are summed up as follows: {PB,PM,PS,ZO,NS,NM,NB} 4.2 The structure and design of fuzzy controller Implicative fuzzy relations in rule base The ith control rule in rule base: Ri: IF E is Ai AND EC is Bi THEN U is Ci The implicative fuzzy relation is： The relation between n rules in the control rule base can be seen as or” , which is the relation of “ union“ , the implicative fuzzy relations of entire rule base are: 4.2 The structure and design of fuzzy controller The production of rule base（规则库的产生） 模糊控制规则的提取方法在模糊控制器的设计中起着举足轻重的作用，它的优劣直接关系着模糊控制器性能的好坏，是模糊控制器设计中最重要的部分。 Generation method of fuzzy control rules production can be summarized as follows: 根据专家经验或过程控制知识生成控制规则。 根据过程的模糊模型生成控制规则。 根据学习算法获取控制规则。 Pay attention to the following questions for the fuzzy control rules summary: 规则数量合理、规则要具有一致性、完备性要好 4.2 The structure and design of fuzzy controller 4.2.3 Fuzzy Reference