Hiroshi Katukura

A knowledge-based approach to the structural analysis of large spacestructures

Analysis is one of the key issues in realizing large space structures. In spite of the fact that a huge amount of accumulation has been done in the field of structural analysis, there is still a need to include newly developed methodologies into analysis codes for production use. This paper introduces an attempt which implements a knowledge-based approach to structural analysis based on the idea that numerical analysis programming can be thought of as a particular type of engineering design. A system is proposed which first accepts the users description of a problem, then generates a program, along with input data, and finally to give a result to the user. In order to test the possibility of this approach, a problem solving model called Organizational Model is introduced and is implemented based on the object-oriented program development.

An Object Oriented Modeling Approach to Intelligent Variable Geometry Trusses

Since an intelligent variable geometry truss (IVGT) is usually equipped with large numbers of redundant actuators for the sake of providing adaptivity, a distributed control is considered a promising approach to dealing with its motion control. In this case, a modeling approach and an integrated model is a key to constructing distributed control systems from both hardware and software. To this end, this paper proposes an object-oriented modeling approach. Through decomposing the control problem domain underlying VGTs into objects, an object model can be obtained to represent various object abstractions and the relationships among these objects. It is shown in this paper that an object model of VGTs is exactly the integrated model for their knowledge organizations as well as the control architectures. Two control schemes resulting from the object models-a hierarchical distributed control and an autonomous distributed control-are discussed in particular. To verify the concepts addressed in this paper, an experimental prototype of IVGTs was manufactured, with a two-level hierarchical distributed control system equipped. With this prototype, an experiment is carried out, simulating a self-construction of space structures with IVGTs in a null gravity space.

A Mobile Agent-Oriented Approach to a Distributed Design Support System

The quality of an architectural design is evaluated from diverse aspects. Application programs that evaluate the quality from a specific aspect have been developed independent of each other. It is one approach to multi-disciplinary design support system to provide a system that incorporates those existing programs without great changes. This paper describes the conception of a mobile agent-oriented community (MAOC) to build such a design support system and agent interchange format (AIF) for agent exchange in MAOC. In MAOC, agents, represented by AIF, carrying a design problem interact with evaluation programs and problem solvers to solve the problem. This paper also describes hypothetical structure of representation of designs. These proposals are conceptual.