Structural redundancy S
is the ratio of the total number of basic and
interface blocks in the structure of the mechatronic module to the number of
necessary functional transformations [9]:
199
(3.6)
Structural redundancy is:
for the motion module
for the mechatronic module of motion
for an intelligent mechatronic module
When designing mechatronic modules, it is necessary to strive to reduce
structural redundancy. This can be achieved by integrating the basic and inter-
face elements.
C
– structural connectivity is a value that characterizes the
influ-
ence
of the level of functional and structural integration on the complexity of
the structural model of the mechatronic module.
The structural model of the mechatronic module is oriented graph (digraph).
Therefore, graph theory can be applied to it. Consequently, the structural
con-
nectivity
of the mechatronic module is determined from the dependence:
(3.7)
where
a
ij
is an element of the adjacency matrix element of the adjacency matrix
A of the structural model of the mechatronic module;
n
is the number of blocks
of the structural model. The adjacency matrix of a structural model having n
structure blocks is the matrix A = ||
a
ij
|| dimension
n
x
n
, for which the element
a
ij
= 1, if there is a link (arrow) directed from the previous block
i
to the next
structural block
j
(i.e. block
i
is adjacent to block
j
). otherwise,
a
ij
= 0.
The adjacency matrix has the following basic properties:
• the sum of all elements of the matrix is equal to the number of links
(arrows lok) of the structural model;
• the sum of the elements of the i-th row is equal to the number of links
(arrows), entering into the j-th block;
• the sum of the elements of the j-th column is equal to the number of links
(arrows) entering the i-th block.
For a mechatronic module with a minimal structure, the structural connec-
tivity
C
= 0, the maximum structural connectivity
C
= 1 has mechatronic
200
modules, in which between any pair of structural blocks there are a pair of
differently directed links (a pair of mutually opposite arrows).
The structural coherence of the structural model of the mechatronic
module with the increase in the level of functional and structural integration
is changing. By the value of structural connectivity, one can indirectly judge
the complexity of the structural model of the mechatronic module. When
designing a mechatronic module, it is necessary to strive to increase the value
of structural connectivity.
Let’s define the structural connection of the motion module, the mechatronic
module of motion and the intelligent mechatronic module.
Figure 3.5 – Structural model of the motion module
We form the adjacency matrix:
We calculate the structural connectivity:
Figure 3.6 – Structural model of mechatronic motion module
Adjacency matrix:
Structural connectivity:
201
Figure 3.7 – Structural model of the intelligent mechatronic module
Adjacency matrix:
Structural connectivity:
Thus, the structural connectivity of the mechatronic module with the
increase in the level of functional integration has changed. We will consider an
integrated intelligent mechatronic module in which a computer control device
and a digital-to-analog converter are combined into one constructive element –
a controller, as well as motor and a mechanical converter – into a high torque
motor. The structural model of such a module is shown in Fig. 3.8.
Figure 3.8
202
We form the adjacency matrix:
Structural connectivity:
The structural connectivity of the mechatronic module with the growth of
structural integration has increased.
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