JPH0282364A - Link mechanism loop generating device and mechanism analyzing system - Google Patents

Abstract

PURPOSE:To effectively use a graph theory and to rapidly derive an optimum loop with a good calculation efficiency by erasing a peak and one side, simplifying the graph of a link mechanism and deriving a fundamental opened loop and a partial fundamental closed loop. CONSTITUTION:For example, the gate mechanism of the paper money inversion at a bank terminal is modelled with a joint and a link and inputted as link mechanism data. Sides e1 to e7 are assigned between fixed joints J1, J2 and J5 and links R1 to R5, both edge points of the side are made into v1 to v6 and a graph expression is obtained. In the graph, from the graph where peaks v2, v4 and v5, in which two sides are linked, are erased, two sides are collected to 1, and simplified, the fundamental opened loop and the closed loop are obtained. Sides e2, e4 to e6 erased at the process of simplification and the peaks v2, v4 and v5 are fetched and the loop corresponding to the original graph is prepared. Thus, the graph theory is used effectively and the optimum loop with the good calculation efficiency can be rapidly derived.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a link mechanism loop generation device for a mechanism analysis system, and particularly to automatic loop generation in link mechanism analysis.

[Conventional technology]

Conventional techniques for deriving loops in link mechanisms include Proceedings of the Japan Society of Mechanical Engineers (ed. 0), Volume 52, 4. This example represents a link mechanism as a graph with joints as edges and links as vertices, and is based on graph theory. Using the adjacency matrix, we obtain the velocity set and derive closed loops and open loops.

[Problem to be solved by the invention]

In the above conventional technology, the loop of the link mechanism is derived using the adjacency matrix of graph theory, but the number of rows and columns of the adjacency matrix matches the number of joints of the link mechanism, and the speed set is
It is obtained by multiplying the adjacency matrix several times.

Therefore, as the number of joints increases, the adjacency matrix becomes larger, which poses a problem in computational efficiency. In addition, the loop obtained by this method is fixed at will, and there is a problem in that the loop cannot be changed depending on the analysis.

An object of the present invention is to provide a linkage mechanism loop generation device that can effectively utilize graph theory to quickly derive an optimal loop with good calculation efficiency, and a mechanism analysis system equipped with the same.

[Means to solve the problem]

” Among the objectives listed in item 1, improving computational efficiency is as follows: (1) If two edges protrude from a vertex in the graph obtained from the link mechanism, a new graph is created by deleting this vertex and one edge. 2) The coupling matrix (A) obtained from the graph and the relational expression obtained from graph theory (A-eT=
A cycle matrix (e
).

Further, derivation of the optimal loop is achieved by (3) determining basic loops that constitute the loop, and combining them according to the purpose to construct the optimal loop.

[Effect]

``Means (1)'' works to reduce the number of edges and vertices in the graph expressing the link mechanism, so the size of the matrix used in graph theory can be reduced, and the efficiency of calculation is improved. Furthermore, since the edges of the graph obtained by simplification already constitute a loop, there is no need to repeat the product of matrices as in the prior art, and a closed loop can be efficiently obtained.

In the above means (3), basic loops constituting a loop are found and a desired loop can be constructed by combining them.

Note that it is desirable to prepare multiple sets of evaluation criteria used when selecting the optimal loop and store them in the rule base.

Therefore, it is possible to shorten calculation time, derive an optimal loop according to the analysis method, and improve calculation accuracy.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

Figure 1 shows a mechanism analysis system, with input device A
Data is input from the simulator B, mechanical analysis is performed using the analysis simulator B, and the results are output to the output device. The link mechanism loop generation device C, which is the object of the present invention, is an analysis simulator B.
is part of the

FIG. 2 shows the flow of the processing procedure of the link mechanism loop generation device Wc. The flow of this process is shown in Figures 3 to 11.
This will be explained in detail using figures. Note that the reference numbers for each step in FIG. 2 correspond to those in FIGS. 3 to 11, respectively.

FIG. 3 shows, as an example of the mechanism to be analyzed, a gate mechanism for reversing banknotes at a bank terminal.

FIG. 4 shows a model of the mechanism shown in FIG. 3 using joints and links, and this is input as link mechanism data.

In FIG. 5, for the model given in FIG. 4, fixed joint J1. ．． J2. Between U5 and link Rr(j
=1.2. ......, 5) has side e+(i-1゜2
, . . . , 7) respectively, and both end points of one side are set as vertices VΔ (j=1.2 . . . , 6) to obtain a graph representation ′.

In Figure 6, in the graph of Figure 5, the vertex V21 V4 + V5 where two sides are connected is deleted, and the two sides are
Simplify the graph by summarizing it.

In FIG. 7, a basic open loop is determined from the graph simplified in FIG. Edge e1 obtained by simplification, T ell
Since e41 and e7 are already in the basic open loop, they can be found immediately.

In FIG. 8, a coupling matrix A is constructed from the graph obtained in FIG. 6, and a cycle matrix C that satisfies the formula A-CT20 is derived,
Find a closed loop. Here, the connection matrix A has a row with vertex 9
If the column corresponds to an edge and the vertex V and edge el are connected, then 1
．． If they are not connected, it is a matrix with O as an element in 5 rows and 1 column.

Further, the cycle matrix C is a matrix whose rows are numbered by cycles and the 2nd column corresponds to the sides, and if the side eI is included in the cycle j, 1°, and if it is not included, O is the J row, j column element.

In FIG. 9, the basic loops obtained in FIGS. 7 and 8 are combined to generate an optimal loop. In this example, the criteria for evaluating the optimal loop are (1) a close loop, and (2) a small number of joins and links.

In Figure 10, a virtual edge e8 and vertex ■7 are added to the loop obtained in Figure 9, and a common edge e between the loops is added.
I try not to have 3.

In Figure 11, the edges and vertices that were deleted during the simplification process in Figure 6 are taken in, a loop corresponding to the original graph in Figure 5 is generated, and it is output to the next processing stage of the mechanism analysis system. .

In the optimal combination in this example, the loop is configured to reduce the number of joints and links, so the number of subsequent analysis processes can be reduced and calculation efficiency increases.

〔Effect of the invention〕

According to the present invention, there is provided a link mechanism loop generation device that, when two edges protrude from a certain vertex in a graph of a link mechanism, deletes these vertices and unifies them to one of the edges to simplify the graph. It will be done. If N edges and vertices are deleted using this device, the size of the connection matrix A will be N rows and N openings, increasing the calculation efficiency of this method, which essentially requires matrix calculations.

Furthermore, since the basic loop has already been obtained by the above method, by combining this with the optimality evaluation criterion, it becomes possible to generate an optimal loop.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of the configuration of a mechanism analysis system including a link mechanism loop generating device, which is the subject of the present invention; FIG. 3 is a diagram showing an example of a link mechanism to be analyzed to explain the processing procedure shown in FIG.
FIGS. 4 to 11 are diagrams showing the results at each processing stage. A: Input device, B: Analysis simulator, C: Link mechanism loop generation device, D: Output device.

Claims (1)

[Scope of Claims] 1. In a mechanism analysis system that analyzes a mechanism including arbitrary open loops and closed loops by expressing the fixed joints and links of a link mechanism as sides and the end points of the sides as vertices, from the vertices. The present invention is characterized by comprising means for simplifying the graph of the link mechanism by deleting the vertex and one edge when two edges appear, and deriving a basic open loop and a part of basic closed loops. Link mechanism loop generator. 2. The linkage loop generation device according to claim 1, further comprising means for deriving the closed loop using a relational expression between a connection matrix and a cycle matrix in graph theory. 3. In the link mechanism loop generation device according to claim 1 or 2, if three or more edges protrude from the vertex, a virtual vertex is provided and the graph is expanded so that two edges protrude from the vertex. A link mechanism loop generating device characterized by comprising means for. 4. The linkage mechanism loop generation device according to any one of claims 1 to 3, further comprising a rule base storing a plurality of sets of evaluation criteria used when selecting an optimal loop. . 5. A mechanism analysis system comprising the link mechanism loop generation device according to any one of claims 1 to 4.