Page 23 - Handbook of Biomechatronics

16 Ahmed R. Arshi

(e.g., the cause for element A to behave in a particular manner, is the
effect of element B whose cause may be the algebraic summation of
the effects of a number of elements). The intradisciplinary subjectivity
in the causal selection process may thus be eliminated. The system ele-
ments defined and described by logico-mathematical causal relations
may also be adopted in the synthesis of new systems, as well as in the
analysis of already existing ones. This approach to synthesis may embrace
a number of characteristics such as the following:
a. Introduction (existence) of an element independent of the observer
(discipline) would indicate a predictable effect (consequence).
Therefore, the causal relationships presented in the synthesis of a
conceptual design would represent a structure which may not
change when the observer is altered. This remains true unless the
nature of functional connectedness is altered.
b. Contribution of individual elements to the system output can be
established and critically analyzed, independent or within the struc-
ture of a discipline.
c. Existence of causal conflicts is an indication of missing or unac-
counted relations, and leads to model expansion or reconfiguration.
Combination of the two concepts of causality and systems isomorphism
would qualify an alternative approach to bond graph description techniques
with emphasis on synthesis as opposed to analysis.

10 COHESION IN DESCRIPTIONS

A purely mathematical approach to systems analysis is all too often an
inadequate means of providing full appreciation of interactions present in a
system. In engineering, however, a view that a picture is worth a thousand
words has generally prevailed and the starting point of analysis of any
dynamic system is commonly a systematic diagram or other graphical or pic-
torial representations. Excellent graphical representations and corresponding
analytical techniques already exist in different domains. When multi-
disciplinary systems are under investigations and biophysical domains are
coupled, the coherency of graphical representation techniques evaporates
and the situation is no longer routine.
The graphical or pictorial descriptions of such complex systems are
commonly extremely generalized mixture of disciplinary notations. Here