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4.7.1 Pattern of drawing sketch
The sketch layout expresses only the basic constructive idea of the mecha-
tronic module, the pattern of drawing sketch reveals this idea more fully. In
the sketch configuration, only a pre-selected part of the technical requirements
is realized without a detailed consideration of the
possibilities for future
implementation of the remaining requirements. The pattern of drawing sketch
takes into account a much larger number of requirements, and that is why the
main idea in it, if unchanged in comparison with the idea of a sketch layout, is
in any case tied to all these requirements.Drawing sketch can combine the first
large-scale layout with non-scaled sketches.
The outlines of the sketch layout are, as a rule, executed in full scale. But,
despite the great completeness and scale, it is still far from drawing the final
layout.
An important circumstance that distinguishes the development of a sketch
layout from the creation of the initial sketch is the need for a certain sequence
in the drawing of individual nodes.
First of all, the contours of the nodes with the largest dimensions (engine,
motion transducers) located in the most constrained areas and not giving the
designer the opportunity to vary their configuration, orientation and location
are put on the drawing. Successful placement of these nodes in the drawing
gives the designer confidence that the remaining nodes (position sensors,
brakes, etc.), which will be applied further
in the final layout drawing, will
not significantly worsen the created layout. Each node applied in the drawing
imposes specific restrictions on subsequent nodes, and therefore not only the
rationality of the layout creation process, but also the form in which it pours
depends on the sequence of drawing. At this stage, the designer must make sure
that the version of the draft outline drawing chosen by him is close to optimal.
The design may contain enough elements to meet the requirements, but not
all elements may be necessary for this purpose. To fulfill the «necessary and
sufficient» condition, the construction should be checked for «redundancy»,
i.e. try to find and eliminate all that is superfluous. Everything superfluous,
not
necessary in the design, can be thought of as «stocks» and divided into
two groups: stocks according to the technical requirements for the mechatronic
module and stocks by the parameters of the self-design that are not directly
related to the technical requirements, first of all, excessive margins and
stiffness.
Reserves for any parameter of the technical requirements implemented in
design, indicate the deviation of the generated conceptual design from another,
more rational. With
the introduction of the scale, as detail of the drawing of
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conceptual layout and transition to the final drawing of the layout of the stock-
pile destruction of the first group becomes more and more effective means of
improving layout and design.
The voids in the structure, indicating the irrationality of the layout can be
considered as stock in terms of available space. The presence of such reserves
tells about the underutilization of the criterion of minimizing the size. The
emptiness inside the mechatronic module can be eliminated by a rearrangement
of parts. This is achieved by reducing the size. Sometimes it is beneficial,
while maintaining the dimensions of the mechatronic module, use the void
for constructive combinations, to better meet any other requirements, such as
accuracy, vibration, operator comfort, etc.
Stocks in the parameters of geometric nature (for example, by angular and
linear displacements of moving parts) are easy to spot on the drawing, what can
be said about stocks on such parameters, such as output power or the accuracy
of the rotation angle. When searching for hidden stocks designer should not
forget about the concept, because the transition from it to the design especially
easy to prevent redundancy.
A consequence of the reduced inventory of stiffness or strength (reserves
of the second group) of individual parts of the
mechatronic module is the
reduction of their mass. In real designs, where everything is interconnected,
the reduction of the size and weight of the individual parts is causing far-
reaching consequences. In particular, the reduced mass, accompanied by a
reduction in the stiffness
characteristics in any detail, may at the same time
be accompanied by improving other rigidity characteristics, is essential for
the normal functioning of the mechatronic module as a whole. Thus can be
obtained a considerable gain in reliability.
With the magnitude of the various «stocks» linked to the selection of types
and dimensions of finished products included in the design of mechatronic
module. For example, the weight and dimensions of
the motor are determined by
developing them power. Reducing required power by reducing any «reserves» in
mechatronic module gives you the opportunity to go to neighboring on a scale
of size smaller engine. But such abrupt terms of weight and dimensions of the
transition almost always opens up new opportunities for better layout options.
It often happens that the implementation of these features componentattribute
completely different, becomes more rational.
Further design is carried out, as it were, on a new «level of rationality» of
the layout, in which the possibilities of sealing the functional load of the parts,
the possibility of their adaptation and partial «integration» and the benefits of
reducing the reserves of both groups are realized to the maximum extent.
Reducing the reserves of the second group is not an easy task, requiring
careful calculations and knowledge of the technological capabilities of today.