Diagnosis of defects on peeled veneers by the fuzzy expert system

单板剥离过程中的质量控制和生产控制是可邀请的程序。在单板剥离过程中，经验丰富、技术娴熟的车床操作员通常会利用自己的经验知识来控制单板车床的运行，以生产出高质量的单板。当他们检测到旋切单板上的缺陷时，他们还可以直观、即时地控制和调整车床的操作。因此，本研究的目的是收集与单板生产相关的熟练车床操作员的经验知识，并建立适用的诊断技术，预测单板生产过程中单板缺陷的原因。我们相信专家系统是解决这类问题的强大而有用的工具。我们通过邮寄问卷收集了车床操作员通过经验获得的关于单板剥离的经验知识。问卷由影响贴面缺陷的原因的填写概率组成，以百分比表示。我们向日本胶合板工业协会所属的118家单板厂和胶合板厂发出了调查问卷。由于传统的专家系统大多是通过产生式规则建立知识库，如果-然后-解释存在一些缺点，我们开发了一种新的专家系统，即模糊专家系统。在模糊专家系统对单板质量模糊理解的基础上，用模糊专家系统来表示单板质量的定义和最优操作条件的决策，使得单板质量的定义和最佳操作条件的确定变得容易和现实。在知识库的构建之后，通过模拟来检验假设单板缺陷下的模糊专家系统的操作过程，指出原因及其概率。在以后的研究中，为了确定系统的可靠性，在实际的旋切作业中，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.