Diagnosis of defects on peeled veneers by the fuzzy expert system

单板旋切过程中的质量控制和生产控制是不可缺少的环节。在单板旋切过程中，经验丰富、技术熟练的车工往往运用经验知识控制单板车工的操作，以生产出高质量的单板。因此，本研究的目的是收集经验丰富的旋切机操作人员在旋切单板生产过程中的经验知识，建立实用的诊断技术，预测单板生产过程中产生缺陷的原因。我们相信专家系统是解决这类问题的强大而有用的工具。通过邮寄问卷的方式收集了车床操作员通过经验获得的关于单板旋切的经验知识。调查表由填充的原因概率，在百分比表示，影响单板缺陷。我们向日本胶合板制造商协会所属的118家单板和胶合板米尔斯厂发送了调查问卷。由于传统的专家系统大多采用产生式规则IF-THEN-解释建立其知识库，存在一些缺点，我们开发了一个新的专家系统，即：模糊专家系统用模糊专家系统来描述单板质量的定义和最佳操作条件的确定，是在充分理解单板质量的基础上进行的。在建立了知识库之后，我们通过模拟试验，检验了在假定单板缺陷情况下模糊专家系统的操作过程，以指出缺陷产生的原因及其概率。在今后的研究中，为了建立该系统的可靠性，在真实的剥离操作中，其验证是不可避免的。

The quality control and the production control in veneer peeling are invitable procedures. During the peeling of veneers, experienced and skilled lathe oprators usually control the operation of veneer lathes by using their empirical knowledges, to produce high qualities of veneers. They also control and adjust the operation of lathe intuitively and instanteneously, when they detect defects on peeling veneers.Therefore, objectives in the study were to collect emperical knowledges of skilled lathe operators concering with veneer production, and to build pu the diagnostic technique which is applicable, to predict causes of veneer defects in process. We believe that expert systems are powerful and useful tools to solve these kinds of problems.Empirical knowledges about the veneer peeling, which lathe operators acquired through their experiences, were collected by mailed questionnaires. The questionnaire was consisted of filling probabilities of causes, in percentage representation, affected veneer defects. We sent the questionn aire to 118 veneer and plywood mills affiliated to the Japan Plywood Manuf acturers' Association.Since the conventional expert system mostly builds its knowledge base by the production rule, IF-THEN-explanation, has some disadvantages, we developed a new expert system, i.e., Fuzzy Expert System. The difinition of qualities of veneers and the decision of the optimum operational condition is formulated easily and realistically if they are represented by the fuzzy expert system on the comprehension of their vaguenesses.After the construction of the knowledge base, we examined the operational procedures of the fuzzy expert system under supposed veneer defects to indicated causes and their probabilities to them through the simulation.In the future study, in order to establish the reliability of the system, its verification is inevitable in the real peeling operation.