Interactive multimedia and artificial intelligence are emerging computer based technologies which have been used in a number of disciplines independently. This paper brings together the developments taking place in these areas to assist the designer in making decisions in the conceptual architectural design process. A prototypical example is presented to highlight the features of this approach.
New approaches to computing based on the developments in knowledge based systems, a sub-field of artificial intelligence, are beginning to have a significant impact on the use of computers in a number of disciplines. In the domain of architecture their applications have been discussed by Coyne et al (1990), and Murthy and Lutton (1993).
The rest of this paper describes issues involved in integrating these two technologies for architectural design with the help of an example.
design, intermediate design and detailed design. The conceptual design stage is perhaps the most critical. At this stage design information is often incomplete, contradictory or inconsistent. The designer is also confronted by what seems at first to be a universe of possible design solutions. Decisions made at this stage will determine the framework for the final design solution. The overall objective of the designer, at the conceptual design stage, is to derive a buildable, integrated design that optimises the solution within the constraints and resources constituted by:
Design involves deciding between alternative courses of action. Not all decisions are critical and the designer needs to ascertain which ones are critical according to the state of development of the design, ie, concept, intermediate, detail. Because design solutions unfold in stages, decisions are often made tentatively and are subsequently reassessed in light of further developments.
While there is usually some initial "hopping" between concept and detail levels as architects generate and test ideas in the process of making design decisions, the initial aim is to establish a conceptual outline or framework that remains fixed for the duration of the design. Further, the activities involved in design are often relatively routine and common to most buildings of the same type. Routine activities include overall siting and planning of the building; selecting suitable structural and construction systems; determining the nature and extent of electrical and mechanical servicing; determining overall costs and time constraints, etc.
Recent design tradition seems to treat each building design problem de novo, as though it had never occurred before. In fact the majority of buildings that are built are answers to problems and needs that are not significantly different from the problems and needs that both contemporary and earlier buildings have already solved and served. There are some design problems that are entirely new, that need to be solved in creative or inspirational ways but design of the bulk of building types, while still benefiting from creative thought, benefits most from accumulated knowledge and experience (Manning 1984).
Architectural designers recognise similarities between design solutions and use "design precedent" as a powerful design strategy. They often draw upon the whole or parts of previous designs, of their own or others, in the search for solutions to new design problems. In-house information incorporating previous drawings and specifications has been observed to be an important source of information drawn upon during design in architectural practices (Mackinder & Marvin, 1982).
Developments in knowledge based expert systems and multimedia technologies provide powerful means to acquire and incorporate knowledge from various sources for assisting in design decision making. These are discussed in the following sections.
KBES have a number of components. The basic ones are: a knowledge base, where the domain specific knowledge is stored in the form of facts and heuristics; an inference mechanism which controls the reasoning and search operations of the system. In addition to these components a KBES may also include: explanation facilities; knowledge acquisition facilities; and a natural language interface. Figure 1 shows the relationships that exists among the essential components of a KBES. A detailed discussion concerning KBES for design is presented by Coyne et al (1990).
Figure 1: Essential components of a KBES
KBES have been developed using special programming languages such as PROLOG and LISP, and by using expert system shells or programming environments. Conventional programming languages such as PASCAL and FORTRAN are usually better suited to perform algorithmic computations. Users of programming languages intending to develop expert systems have to start from scratch but the use of commercially available expert systems shells can be more convenient as they already have built in expert system components. For this research use of HyperCard, a software development tool made available by Apple Computer Inc with the purchase of its computers, has been used.
They could be in different formats such as text, photographs, videos, tape recordings and scanned images. Integration and presentation of information of such variety in a meaningful manner is a major challenge. Thus the development of interactive multimedia based intelligent systems requires a great deal of knowledge in putting together the access structure and the information relevant to the subject matter under consideration. Figure 2 gives an overview of the interaction that can take place between the designer and a KBES incorporating multimedia features.
Figure 2: A KBES for architectural design with multimedia facilities
Here the designer can access multimedia features under two situations. In the first instance the designer may find that he/she is unable to provide sufficient information for the KBES to propose design alternatives. In such a situation the designer is provided with additional information about by-laws, building products, performance requirements, physical context, design objectives, and so on. This information may take the form of text, diagrams, photographs (colour or black and white), voice and video clips. In the second instance information to assist the designer to choose between alternative design solutions is offered by the KBES. This would include demonstrations of how each solution has been used by other designers. This information may again take the form of video clips, images, voice commentary on the strengths and limitations to be considered and so on. We feel that providing this type of information at these two stages in the use of a KBES will greatly assist the designer to make more informed decisions more expediently.
Figure 3: Nine possibilities for positioning an industrial building on a large site
Even an inexperienced designer could identify the possible positions shown in Figure 3, but it takes the heuristic knowledge gained from experience to be able to confidently, logically and expediently exclude some of the possibilities.
Drury (1981) identifies some of the critical issues that an expert may consider when determining the positioning of industrial buildings. These include the following:
Figure 4 describes how a designer interacts with HYPEREX to arrive at a suitable set of options for positioning an industrial building on a large site. Here the designer selects the "building position" item under the "decisions to make" menu. This menu is a "card" in a HyperCard stack, and is the starting point of system.
Figure 4: An example from architectural design using an interactive
multimedia based intelligent system
It should be noted that the type of advice given by a KBES at the conceptual stage of design should allow the individuality of the designer to be expressed. Therefore, in this example of building positioning, solutions are not expressed by the system as (say) cartesian coordinates but as types of positions thus still offering the designer considerable flexibility.
Through the use of appropriately designed KBES for design, a designer is able to achieve a significant reduction in the time usually involved in analysing design problems. They are also able to establish a conceptual framework that avoids costly redesigns at later more detailed stages in the design process.
Appropriate material collection and its presentation is a very time consuming and complex process. One could also encounter problems with regard to well known designers not being able to spend time to provide details of their works and decision making strategies. One also needs to take account of copyright issues related to the use of materials from a number of different sources. The developments taking place in computer hardware technology in conjunction with the techniques being developed by the authors should alleviate some of the problems.
Coyne, R., Rosenman, M., Radford, A., Balachandran, B., & Gero, J. (1990). Knowledge based design systems. Addison Wesley, New York.
Drury, J. (1981). Factories planning, design and modernisation. The Architectural Press.
Mackinder, M. & Marvin, H. (1982). Design decision making in architectural practice: The roles of information, experience, and other influences during the design process. Institute of Advanced Architectural Studies, University of York, UK.
Manning, P. (1984). A strategy for multi-professional design of buildings. Can. J. of Civ. Eng., Vol 11.
Murthy, H. & Lutton, L. (1993). The place of knowledge based expert systems in the CAD of buildings. J. The Architect, Spring issue.
|Authors: Dr Hari Murthy, School of Architecture, The University of Western Australia, Nedlands; WA 6009. Tel. 09 380 2587. Fax. 09 380 1082. Email. email@example.com
Mr Linley Lutton B. Arch. ARAIA, The Building Management Authority, 2 Havelock Street, West Perth, Western Australia. Tel: 09 222 5555 Fax: 09 222 5055
Please cite as: Murthy, H. and Lutton, L. (1994). Interactive multimedia based intelligent systems in architecture. In C. McBeath and R. Atkinson (Eds), Proceedings of the Second International Interactive Multimedia Symposium, . Perth, Western Australia, 23-28 January. Promaco Conventions. http://www.aset.org.au/confs/iims/1994/km/murthy.html