AN EXPERT SYSTEM FOR PRODUCT COMPONENT JOINING DESIGN*

Prof. Huang Tai-Shen,LeeCheng Hui

Graduate Instituteof Design, ChaoyangUniversity of Technology, Taiwan

Abstract:

Financial supported by Chaoyang University of Technology.

The main purpose of industrial Design, which is an activity of creative and developing products, is to develop a product that is not only concerning appearance, but also noticing the relationship between structure and function. The characteristics of product such as the sense of sight, the tactile sense, safe, and convenience must satisfy people’s needs. Industrial design is a process-oriented creative activity that contains research and analysis, product definition and standard, design and model making, refinement and testing, tooling and manufacture[3].When product component joining method contain many choices, a valid assemble sequence is necessary[4].If there is an integrated expert system providing the useful information during design process, designers will realize to notice the detail design soon. An integrated expert system was developed to manage the joining with each parts of a product and help designers to build the expert cognition. It would be not only to shorten the product design cycle but also to be effective in the process of product innovation.The integrated expert system could translate concept into CAD data and provide the pre-experiment information to the new designers.On the other hand, the expert system could transform concept to knowledge to provide designers mass integration of experience and knowledge. In resent years, the issue of knowledge-based economy presents a company could not take advantages of competition by holding tangible assets, becauseintangible knowledge takes place of tangible assets. Accumulating knowledge becomes very important. This paper interprets the relation to accumulating knowledge that makes designers and companies add intangible assets to build up their own competitive power.

Keywords:Industrial Design, Expert System, DFA, MorphologicalAnalysis, Virtual reality technology

Financial supported by Chaoyang University of Technology.

1. Introduction:

When designer want to design new product,designer must consider the appearance and combining problems at the same time.Design Company or part time designer often designs the different kind of product.But designer or learning design’s people that very difficult to touch or understand all product of realms completely. The detail and the design point that not the same of different realm. Just touch the design of the new realm, must a design for completing and the depth that solve problems all contain drawback, must modify once again.It can't be fast to resolve the core problem exact center. If can provide the design related informationat this time.That understand the each product and must notice sooner, such on coming not only can shorten to design time that process need, and design to the product feasibility but also already higher really recognize to increase to design the efficiency.

This research lends support to an Expert System for product component joining design.The development combines the structure of the data concerning the component, providing the design the information, lending support to work on to design the coalescence method or concepts that the worker gets from it the exactitude, acquiring the best coalescence method, constructing in the product design.

The system ignoring to design or work to the learning in the industry design the related personage, can promote the convenience, quality of design and manufacturing and enhance the company competition ability. Onthe teachings in the educational circles itcan be used as the design and engineering department the usage, past to design to say that is a very important and useful application development to plan.

2. Definition of the Problem:

At every stress the modern society of the efficiency, the market of the height competes and the information circulates the fleetness to get under condition, the strategy of the uneconomical product development process and mistake will cause market up of defeat.[1] Any new product finally must by processing of any kind of tradition or forerunner way to complete the spare parts of manufacture.At pass by to assemble the step to complete the last product.And in assembling process the coalescence piece such as bolt button up, screw, and nut etc. It will affect the shape and construction designs of the product, therefore, in productdesigningprocess, must consider the coalescence piece of coalescence method, usage, and join together the strength of etc. the problem.Along with the extensive usage of the computer, also produce the huge influence in industrial design developing and educating similarly, past much more current with the toolofadoptioncomputer aided industrial design(CAID).Carry on the design and the painting of the styles or the work of the engineering diagram preparations.

Atthe traditional design process concerning the designof the coalescence. Depend on mostly experienced designer in actual situation to resolve physically fall among of problem, thus of result is a few and serious weakness:

1.The dictate heart of the similar teacher and pupil system spreads.The way can't match the current that the present knowledge delivers quickly.In addition some even is a false message at mislead to design the personnel.The result that loss because the design of the mistake.

2.It is not has the related design data to be provided as search so the result that can't be instant the best coalescence method rightlyof design.Even just consider to process in follow-up stage and the problem on the construction, and cause to design serious result that hold up whole degree of progress' development again.

3.In product developing process, from design the programs, such as concept, first step design, modification and minute part designs and manufacturingetc, the possibility causes because of the error or experience shortages of the certain process middleman member considerable cost.

Crisis that university education faces at the present time, include the curriculum and can’t match with the industry need well, student's character and employment wills are low to fall the etc,.Educating the result reflects the industry to develop, causing the industry competition ability decline, affecting the national strength, relating to the graveness[5].

In the product design development process, the model manufacture and molding tool developments is to design the process in extremely important part, but design the department the student the lack product to model to read aloud with the basic concept of coalescence, with the result that the finished product designed extremely lacks of the feasibility of the production, even having two a design that stick to match together and not make join together ascends in work with the glue, common problem that is unique most design student’s.Even is an engineering course although the student understands the parts of coalescence method, but lack of the ability of design, with the results that cause the product to have because of again designing of the construction and shape the delay in developing the timing.In the aspects of industry, also because the experience is mutually lost and cause the ability of designing to reduce, usually needing to carry on the training to make up professional shortage on the ability, but also therefore affect the whole and sexual development degree of progress.In the aspects of computer aided industrial design, the CAD passes for too in devote one's mind at provide to design the final form to present, is also so-called geometry of the style ability.In fact, at the time of using the computer aided industrial design, the designer is also opinion and helps that needs to suggest the sex, in order to make the decision in designing process, this also extremely lacks and needs the place of the improvement at the present time.

3. The Genetic Algorithm:

3.1 What Expert System:

The Expert System is a branch of artificial intelligence(AI). The application comes from the professional knowledge of expert in great quantities to solve problems. Expert due to training and experience, own the professional knowledgein particular realm, namely the professional technical ability and knowledges that ordinary people have no.Because the professional knowledge, the expert is not only specialized knowledge of a subject, solve problems hour but also more more efficient than ordinary people.When Expert System just start developping in 70's. It is a specialized knowledge, but all call the Expert System till the system of any application in today Expert System technique.Many help the tool of developping the Expert System to also were under a great deal of need developped out in order to, include the Expert System program language, development environment mutually hardware etc[6].

The knowledge in the Expert System can be an expert to provide directly of, also can by book, magazine last or by have the person of related knowledge and experience to acquire.These knowledge and rule were deposited in the Knowledgebase.The earlier period of Expert System is called Knowledgebase Expert System, also calling knowledge system[10].

Ernst[11] defines Expert System as a "Consulting System".It is design come support professional personnel to a particular knowledge realm carries on to reason logically. The Expert System is within the scope of similar mankind's expert of the concept, regard resolving certain particular problem realm as the target, what problem realm point is a certain problem scope, for example medical science of or expert whom engineering learn, all ability appropriate resolve the professional knowledge in oneself of problem.For example a medical expert wanted to cure to get the patient of the infectious disease, and then he must have the sufficient knowledge, making sure to know what condition of illness will cause and should grow the disease. In this case the knowledge realm would be the medical science, including the disease, condition of illness and treatment methods.

Expert System usually indicates the method to appear with the pattern of"IF" and "THEN". This rule indicates appearance and cause and effect relations of expert's knowledge, for example:

"IF" weather became cold"THEN" I will add clothes.

Precondition with "IF" for problem of pioneer, and it is the result that "THEN" this part shows that conclusion indicates.In the Expert System the expertise and the inference engine is two independent parts, so how to own the Knowledgebase in of description that knowledge inputs according to the user, through certainly reason logically the step, take in to infer the possible answer, become a strategy in count for much solution.

3.2 The basic Expert System constitutes:

A Knowledgebase Expert System of integrity included the six parts.[7]Each constitute a correlation, such as figure 3-1.The arrowhead in the diagram represents the data and knowledge it to fly to.

Figure 3-2the structure of the Expert System

1. Knowledge Base:

Use to the knowledge of storing the generality and experience that the Expert System need, it included many facts and rule.The knowledge source can be the expert of that realm or other knowledge sources, for example related research papers, periodical etc. cultural heritage.Among them experience knowledge is by the experience of many years that mankind's expert accumulate and get.

2. Inference Mechanism:

It is include the Interpreter and Scheduler. That is a rule and procedure, method to drive the mechanism in the Knowledgebase.The solution translates the function of the machine as the search to also use the knowledge in the Knowledgebase, really identifying the fact it false, and make use of the rule to inference the new fact.The scheduling machines then apply to carry out order of sequence with the decision rule.

3. User Interface:

The interface is an Expert System to emphasize one of the high and interactive and main characteristics.Its function lies in the double of providing the user and system toward communication.A good user interface needs the operation that can help the user to understand the system clearly, reduce the difficult system usage and complicacy, and can let user operated in the system in the process, acquire the most and the most perfect information.

4. Knowledge Acquisition Facility

The engineer of the knowledge will and realm the expert interviews the experience knowledge of the income, picking the equipment through the knowledge, carrying on the knowledge it to pick, identify and safeguard, making the Expert System have the development and the function that edit.

5. Explanation Facility:

The main function lies in providing a piping for explaining, letting the user understand the fact of the rule and basis that the hour of operation of system inferences, operating the clarity of the hour with the keeping system.

6. Working Memory:

Store the system in order to in operating process the data or systems that need creation a result, for example the knowledge, fact of the Knowledgebase, and operate the Knowledgebase to inference and know the new information to know or new fact.

The product develops in the process, having an equal and important link. The construction usually has over the total manufacturing 50% cost. Therefore with company control the process or ways of the construction to count for much the cost budget that can carry.The experience can provide the designer with the standard of a valid decrease construction cost, making use of the knowledge or standards of the Knowledgebase in addition to letting the process of the construction have a standard for according to, also can let the product maintain the certain manufacturing quality.[12]

3.3 What is Design for assembly：

Usually assemble the design method of the direction produces with the product of assemble condition be used as the design activity of having the initiative the consideration, that is at design the stage to evaluate the product with the assemble principle, and further resolve the assemble problem of possible appearance.Familiar product component then the design belongs to this category then, can let product at the design stage of earlier period expects to assemble after dismissing then, the problem that may fall among, also can reduce time that the design need.

3.4Assembling the direction designs principle:

For each component and speech, the design of the assemble direction is also a simplification to assemble a kind of design of the work, its main principle is:

1. The component that can remove or can merge.

2. The assemble procedure or actions that can abridge.

BoothroydDewhurst(1991) thinks that the production cost of the homework process also at the request of see as one of the main factor consideration that must consider, can insure the product to match to assemble thus on-line.

Siddiqu and Rosen(2001) assertions combine all considerations of design while designing product components set, including the target, link relation of the design and the consideration of the assembles, developping with the convenience can let other similar product also can with in general use terrace.Let product the design develops toward the concept that module turn From and exaltation the efficiency and the quality that product design. In their research forerunner makes the component and designs the fit degree of the target, then the definition conjunction relates to. Each component function of relation strong or weakFinally.Carries on the consideration of the assemble, this research established successfully in general use similar to the design programming terrace of the component in the different form coffee pot.[8]

3.5MorphologicalAnalysis：

MorphologicalAnalysis in 1951 by Switzerland astronomer Zwicky creates. The extensive application is in each realm if design the engineering, manufacturing engineering, industry engineering, person machine engineering and building design etc.So-calledMorphological, is point to the object of the research of the form or style, so, the appearance analysis is a kind of to go to the type of analytical product possibility in systematical way, its distinguishing feature lies in and can manage the detail of problem with the simple and objective whereabouts, can more definite control problem, at the same time can with comprehensive analytical problem.

The target of MorphologicalAnalysis to lie in all possible solution projects in collection problemsuch as figure 3-6. Design the important parameter that the personnel must look for all answers, and every kind of number of each parameter is all realization methods with possible components.The appearance analysis method of the typical model will produce the speculation and valuation speculation strict demarcations. Zwicky thinks" really keep off the prejudice is the initial term that the appearance analyzes the personnel", he once subdivide to the analytical method in appearance, but design the homework up common use go to of is Morphological chart method.(Roozenburg & Eekels, 1995)