Search

The paper presents a behaviour-driven functional (B-FES) modelling framework for functional design of mechanical products based on a rule-based causal behavioural reasoning step to guide the design process. A new representation scheme called rule-based behavioural representation (causal behavioural rules) was developed to facilitate causal behavioural reasoning, with which the interconnected physical behaviours can be reasoned out from a desired function. The behaviour schema was then used to select and arrange embodiments (abstractions of physical artefacts) to develop a set of potential concept variants. The proposed approach was not only useful in the creation of new configurations (combinations) from a library of standard physical behaviours, but also it might be used to generate specifications of new physical behaviours. A design case study of a terminal feeding unit is presented to demonstrate the practicality of the proposed approach. [ABSTRACT FROM AUTHOR]

Mechanical systems with adaptable functions are versatile in functionalities and compact in physical structure than ordinary ones, hence are useful in many industrial and agricultural applications. One aspect of design analysis for these systems is the analysis of functional coupling degree among the adaptable functions, because this is a measurement of how compact and material-effective (thus cost-effective) the systems are. Existing work on functional coupling is mainly oriented to multiple-function systems rather than adaptable-function systems, where the former owes multiple functions without the need of adjustment or replacement of system components. The purpose of this paper is to investigate the methodologies for the evaluation of functional coupling and component importance of adaptable-function systems, so as to provide support for the development of this kind of mechanical systems. To this end, the function-component dependency is investigated first by exploiting the methods for design change propagation, whereby a change possibility matrix is proposed and calculated, and a function- component incidence matrix is developed. Based on the incidence matrix, the functional coupling degree is evaluated to measure the coupling between individual functions, and a comprehensive coupling degree is evaluated to measure the functional coupling of the entire system. These results are then used for the evaluation of component utilization and component importance. Finally, a design case of an adaptable-function juicing machine is studied to illustrate the proposed methods as well as the related concepts. [ABSTRACT FROM AUTHOR]

Supporting the conceptual stage of mechanical product design has been recognized as a challenging research work. This is an area that is not addressed by current computer-aided design systems. In this paper, we present our work on the identification of functional design knowledge and the strategies for its organization. The functional design knowledge is aimed at assisting the conceptual stage of mechanical product design using a dual-stage functional modelling framework proposed by us. Several aspects of functional design knowledge are identified and represented, including function decomposition and functional mapping knowledge, physical structure and physical phenomena knowledge, as well as schematic geometry knowledge. These different aspects of knowledge are organized into three levels: meta level, physical level, and geometric level. A number of libraries are used to implement the design knowledge and its organization. The strength of the approach is that it encompasses very comprehensive aspects of functional design knowledge, and it provides a useful means for compiling past design experience in a formalized and structured form. To demonstrate how the approach can be applied, an example of automatic assembly system design is also studied. [ABSTRACT FROM AUTHOR]