Page 29 - Handbook of Biomechatronics

22 Ahmed R. Arshi

The relationship between the constituent elements and in particular their
effects on one another, within the causal structure of the system as a whole,
could be critically analyzed and well understood. As a result, the designer
gains a clear understanding of the system and is able to benefit from the infor-
mation feedback to improve on the design or even reshape the original
structure of the problem. The design can therefore, to a large extent, be
completed and the root characteristics established prior to introduction to
any discipline or energy domain. The formation of the solution variants
which may be the consequence of introducing the ICD into alternative
energy domains can be achieved through appropriate substitution of
corresponding disciplinary elements. The particular advantages or disadvan-
tages of individual disciplines quickly becomes apparent. Here, the extent
and range of solution variants has already been decided upon through the
complexities of the criterion function. Any necessary extensions of the
model to cater for any particular requirement associated with any one dis-
cipline could also affect the choice of disciplinary elements. Handling of
overriding design specifications and the general decision-making process
are all based on an analytical structure which is derived from a causally valid
and mathematically described model and hence reduces the reliance on lists
or linguistic constructs.
The designer can therefore formulate or design an optimum system
to begin with in an ideal form and could even optimize the design at this
elementary stage. All possible ideas could be implemented, tested, analyzed,
and simulated using the ICD.

12.3 Bond Graph Technology in Synthesis
A word graph in its conventional form cannot convey sufficient detailed
information about a system. It simply set out to describe the essence of
the system. Perhaps not unlike preliminary sketches drawn by architects.
It is, however, the first step in a line of progression to a detailed design with
its origins in an idea. The word graph could then be augmented to establish
underlying causal relationships among constituent elements. Augmentation
at this point means an introduction of the basic causal structure, thereby
indicating input-output relations governing the interchanges of energy
and flow of power in the system. Inclusion of causal relations in the structure
of word graphs is not intended to give rise to formulation of mathematical
relations but to encourage feedback during abstract and conceptual stages of
synthesis. In such a sphere of conceptuality, adoption of conceptual causality