JPH10268922A - Shortest route retrieving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently retrieve a shortest route in a short time by generating a single assembly obtained by connecting plural assemblies and continuing selecting the shortest route while recombining connection to connect all the points as one shortest route. SOLUTION: A work station 4 connects between with a nearest mounting position by each mounting position of a wiring pattern generated by the mounting face of a wiring substrate to generate plural line segment assemblies and then connects nearest mounting positions between with the nearest line segment assembly are connected with each other to make one line segment assembly by each line segment assembly. All the mounting positions are connected to be the single shortest route by keeping selecting the shortest route while recombining connection so as to connect a mounting position connecting at least three places with the mounting positions of the other two places or the other place at this time. Thus, the work station 4 mounts electronic parts assigned to each mounting part 6 to 8 successively to corresponding wiring patterns through a shortest route.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Table of Contents] The present invention will be described in the following order. Technical Field to which the Invention pertains Prior Art Problems to be Solved by the Invention Means for Solving the Problems Embodiments of the Invention (1) Overall Configuration of CAM System (FIGS. 1 and 2) (2) For Each Various Electronic Components (FIG. 3 to FIG. 7) (3) Mounting order determining procedure for all types of electronic components (FIGS. 8 to 9B) (4) Operation and effect of the embodiment (5) Other Embodiment Effects of the Invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shortest path search method, and is suitably applied to, for example, a mounting apparatus for sequentially mounting electronic components corresponding to a wiring pattern on a wiring board.

[0003]

2. Description of the Related Art Conventionally, in this type of mounting apparatus, electronic components are sequentially mounted one by one on a wiring pattern on a wiring board using a single head. At this time, a plurality of types of electronic components are mounted in units of several tens to several hundreds on a single wiring board. Since efficiency is low, usually, one or two types of electronic components are all mounted on a wiring board, and then another one or two types of electronic components are all mounted on the same wiring substrate, and so on. Until the wiring pattern is mounted, electronic components are mounted in one or two types.

[0004]

By the way, a computer or the like is designed so that the suction head holding one or two kinds of electronic components can be successively moved to the mounting position of the corresponding wiring pattern in a relatively short time. It is necessary to previously search the shortest moving path of the suction head using the type of the electronic component.

However, after calculating all the travel routes,
In the method of searching for the shortest movement route from the calculation result, when the number of mount positions is increased due to a design change or the like, an enormous amount of calculations must be performed again, which is not practically sufficient. Was.

In addition, only appropriate travel routes are sequentially narrowed down.
In the method of searching for the shortest moving route by comparing the moving times of the moving routes only one after another, it is extremely difficult to search for the shortest moving route obtained in consideration of all the moving routes. There was a problem.

[0007] Further, in the method of simply determining the moving path in order from the closest mounting position, the mounting position at the longest distance remains at the end, and as a result, it often differs from the shortest moving path. Practically, there is a problem that it is difficult to search for the shortest moving route.

The present invention has been made in view of the above points, and it is an object of the present invention to propose a shortest path search method capable of efficiently searching for the shortest path in a relatively short time.

[0009]

According to the present invention, there is provided a shortest path search method for searching for a shortest path among paths passing through a plurality of given points. Connect multiple aggregates by connecting the closest points to the closest aggregate for each aggregate after generating multiple aggregates consisting of points by connecting between nearby points Generate a single aggregate. Then, for each point that produces a single aggregate, continue to select the shortest path while rearranging the connections so that the point is connected to the other two or one other point, All points should be connected as one shortest path.

[0010] In this way, the amount of calculation can be remarkably reduced as compared with the case of calculating the combination of all points and searching for the shortest route, and can be used sufficiently for practical use.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

(1) Overall Configuration of CAM System In FIG. 1, reference numeral 1 denotes a CAM (Computer Aided M
an CAD system for CAD (Computer Aid)
ed Design) After a wiring board (not shown) designed by the terminal 2 is manufactured by the board manufacturing unit 3, various electronic components are mounted on the work station 4 in the mounting process stage by the mounting apparatus 5.
It is made to mount according to the control of.

The CAD terminal 2 sets the coordinate data for each reference number assigned to each wiring board, and sets the polarity of each wiring board and the pitch of the through-hole, so that the data is converted into CAD data S1. It is supplied to the production section 3 and the work station 4.

The board manufacturing section 3 is a wiring board (not shown) corresponding to each reference number based on the CAD data S1.
Is manufactured, and the respective wiring boards are sent out to the mounting apparatus 5. The mounting apparatus 5 has first to third mounting portions 6 to 8, and mounts various electronic components (not shown) on a wiring pattern of a wiring board. in this case,
To each of the mounting units 6 to 8, a jumper wire, an axial component, and a radial component are supplied as corresponding predetermined types of electronic components.

The work station 4 includes, in addition to the CAD data S1, parts list data S2 and mounting process data S2.
3 is input according to the operation of the operator. The component table data S2 is data representing the component number of the electronic component with respect to each reference number, and the mounting process data S3 is used to balance the mounting times of the first to third mounting units 6 to 8. This is data representing the ratio of the number of electronic components mounted in the mounting units 6 to 8. Further, in the database in the work station 4, internal data indicating the component shape, size, and the type of the corresponding mounting part for the component number of the electronic component are set in advance.

The work station 4 has the CAD data S
1. Based on the parts table data S2, the mounting process data S3, and the internal data, it is determined which of the first to third mounting units 6 to 8 mounts the electronic component corresponding to each reference number. After that, an algorithm for determining the order of mounting the electronic components by the shortest path is created for each of the mounting units. The algorithms thus obtained are sent to the first to third mounting units 6 to 8 as mounting control signals S4 to S6, respectively.

When allocating electronic components to the first to third mounting units 6 to 8, respectively, all the electronic components having the same part number are mounted on the same mounting unit, and the number of mounts of each mounting unit is reduced. Make it equal to the specified number ratio.

As shown in FIG. 2, the first to third mounting portions 6 to 8 are formed with rails 16 and 17 for transporting the wiring board PWB on the gantry 15, and
Is located near the parts supply table 18 and the head unit 19.
Is provided. In this case, the operator visually confirms the layout table of all types of electronic components for each of the mounting units 6 to 8 printed by the work station 4, so that all the components required in advance at the predetermined positions on the component supply table 18 are obtained. Kinds of electronic components EC are provided.

The wiring board PWB supplied from the board manufacturing section 3 (FIG. 1) is moved along the rails 16 and 17 in the direction indicated by the arrow x, and is positioned at the front of the head unit 19. The head unit 19 includes mounting control signals S4 and S5 given from the work station 4 among the plurality of electronic components EC placed on the component supply table 18.
Alternatively, after picking up the electronic components EC to be mounted based on S6, the electronic components EC are sequentially mounted one by one corresponding to the mounting position of the wiring pattern of the wiring board PWB.

Thereafter, the wiring board PWB on which various electronic components are mounted in the first to third mounting portions 6 to 8 is
It is sent to the hand mount unit 9 (FIG. 1), and after the remaining electronic components are mounted by the hand of the worker, it is sent to the DIP unit 10. The DIP unit 10 generates a circuit board PCB by immersing and soldering the wiring board PWB in a molten solder bath. Thereafter, the circuit board PCB is sent to the subsequent set assembling process.

(2) Shortest path search processing procedure for each type of electronic component In this embodiment, a predetermined type of electronic component assigned to each of the mounting units 6 to 8 corresponds to the wiring pattern of the wiring board. As a pre-stage, the work station 4 executes the following processing when creating an algorithm for determining the shortest path for the head unit 19 to move between the mounting positions of the wiring pattern.

When the work station 4 enters the shortest path search processing procedure RT1 shown in FIG. 3, in step SP1, the closest points are searched for each mount position (point) of the wiring pattern, and a search is made between the points. By connecting with a line (an imaginary line, the same applies hereinafter), a plurality of line segment aggregates including the points are generated. For example, FIG.
As shown in (A), when ten points P1 to P10 are set on the screen D representing the mounting surface of the wiring board,
By connecting the closest points among the points P1 to P10 with a line, the line segment P1-P2-P3 and the line segment P4-P
Three line segment aggregates C1, C2 and C3 consisting of 5-P8-P5-P6-P7 and line segments P9-P10 are obtained (FIG. 4 (B)).

Subsequently, the work station 4 proceeds to step SP2, searches for the closest line segment aggregate for each line segment aggregate, searches for the closest points between the adjacent line aggregates, and draws a line. tie. In FIG. 4B, 3
The closest ones of the line segment aggregates C1, C2 and C3 are the line segment aggregates C1 and C2 and C2 and C3, and the point P is located between the line segment aggregates C1 and C2.
3 and P4 are the closest, and points P4 and P9 are the closest between the line segment aggregates C2 and C3. Therefore, by connecting the points P3 and P4 and the points P4 and P9 with lines, all the line segment aggregates C1 to C3 can be combined into one line segment aggregate CA (FIG. 4).
(C)).

Thereafter, the work station 4 moves to step SP3, where the point where three or more line segments intersect is 2 points.
While the line segment that intersects with the point is recombined with another point so that the point intersects with the following line segment, the shortest route among a plurality of routes formed by the recombination is selected as the actual shortest route. That is, FIG.
In (C), the point where three or more line segments intersect is P
4 and P5 (indicated by black circles). First, for the point P5, the line segment P5-P8 is rearranged into the line segment P6-P8. As a result, the line segment P4-P5-P6-P8 and the line segment P4
-P6-P5-P8 hold (FIG. 5
(A)), but the shorter route is a line segment P4-P6-P5-P
Since it is 8, this is selected as the actual shortest path.

Similarly, for the point P6, the line segment P6-P8 is recombined into the line segment P7-P8 to obtain the line segment P5-P8.
2 of P7-P6-P8 and line segment P5-P6-P7-P8
5 (B), and selects the shorter line segment P5-P7-P6-P8 as the actual route (FIG. 5 (C)).

On the other hand, a point P where three or more line segments intersect
4 (FIG. 5C), the above-described processing is performed to select the actual shortest path. As a result, as shown in FIG. 6, all the points P1 to P10 are connected to the shortest path,
-P2-P3-P4-P10-P9-P5-P7-P6
−P8 can be connected by one line.

As described above, the work station 4 connects all points as one shortest path, and then proceeds to step S.
The process moves to P4 and the processing procedure ends. In this way, the workstation 4 can create an algorithm for sequentially mounting a predetermined type of electronic component assigned to each of the mounting units 6 to 8 on the corresponding wiring pattern in the shortest path.

By the way, in step SP3 shown in FIG. 3, when a line segment intersecting the point is recombined with another point so as to eliminate a point intersecting the three or more line segments, for example, as shown in FIG. If there is only one other point that intersects the point PC with respect to the points PA, PB and PC where the line segment intersects (i.e., the end point), the other point will eventually be the start point or end point of the route. Because there is a possibility, the point P
The line segment intersecting C is not recombined with another point, and the recomposition is switched to another point PA or PB so that the intersection of point PA or PB is eliminated first. Thereafter, the point PC may intersect with two or one line segment in accordance with the above-described algorithm.

(3) Procedure for Determining Mounting Order for All Kinds of Electronic Components As described above, the shortest paths for the head unit 19 to move between the mounting positions are created according to the algorithm shown in FIG. When an algorithm is created so that the shortest path of the above is further taken as a single shortest path, the following processing is executed.

When the work station 4 enters the mount order determination processing procedure RT2 shown in FIG. 8, the work station 4 proceeds to step SP10.
In the above, after searching for a point at one end of the shortest path closest to the movement start position of the head unit 19 among a plurality of shortest paths set for each electronic component, the point is set as a movement start point. For example, as shown in FIG. 9A, when three shortest paths M1 to M3 are set on a screen D representing a mounting surface of a wiring board, each of the shortest paths M1 to M3 is set.
One end point P _2B closest shortest path M2 from the movement start position F of the head unit 19 of the three is retrieved as a moving start point.

Subsequently, the work station 4 moves to step SP11, and, based on the movement start position of the head unit 19 and the other end point of the shortest path to which one end point is connected, the shortest closest to the other end point. Search for a point at one end of the route. Figure 9 (B) in time relative to the point P _2A of the other end of the shortest path M2, point P _1A shortest path M1 is searched as the closest point. Similarly, a point P _{1B at} the other end of the shortest path M1
Is used as a reference, the point P _3B of the shortest path M3 is searched as the closest point.

[0032] As a result, as shown in FIG 9 (B), by connecting all of the shortest paths M1~M3 as the shortest path one, the movement end position of the head unit 19 the point P _3A of the other end of the shortest path M3 It can be. After connecting all the shortest paths as one shortest path, the workstation 4 moves to step SP12 and ends the processing procedure. Thus, the workstation 4 can create an algorithm for determining the mounting order for all types of electronic components on the wiring board.

(4) Operation and Effect of the Embodiment In the above configuration, the work station 4 connects between the mounting positions closest to each mounting position of the wiring pattern generated on the mounting surface of the wiring board. After generating a plurality of line segment aggregates composed of the mount positions, the closest mount positions are connected to the closest line segment aggregate for each line segment aggregate until one line aggregate is formed.

At this time, by continuously selecting the shortest path while rearranging the connections so that the mount positions to be connected at three or more positions are connected to the other two or one other mount position, all the positions can be selected. The mounting position can be connected as one shortest path, and thus the workstation 4 can be used to mount predetermined types of electronic components assigned to each of the mounting units 6 to 8 in sequence on the corresponding wiring pattern in the shortest path. Can be created. As a result, the amount of calculation of the workstation 4 can be significantly reduced as compared with the case where the shortest path is searched by calculating all combinations of the mounting positions.

Subsequently, after searching for a mount position at one end of the shortest path closest to the movement start position of the head unit 19 from among the plurality of shortest paths obtained from this algorithm, the shortest path including the searched mount position is used as a reference. It is possible to connect all the shortest paths as one shortest path by continuously connecting the closest one end or the mounting position of the other end between the shortest paths so as to be connected as one path, and thus work. The station 4 can create an algorithm for determining the mounting order for all types of electronic components on the wiring board.

As described above, the work station 4 is provided with the first
After creating the above-described algorithm for each of the third to sixth mounting units 6 to 8,
8 and transfer the same, and print out a layout table of all types of electronic components for each of the mounting units 6 to 8 based on the algorithm. Thus, the operator can visually check the layout table and supply all necessary types of electronic components EC to predetermined positions on the component supply table 18 of each of the mounting units 6 to 8 in advance. The units 6 to 8 can avoid a stop state due to a shortage of electronic components, and can perform the mounting operation by the head unit 19 in the shortest time.

According to the above configuration, when determining the order in which the predetermined type of electronic components assigned to each of the mounting units 6 to 8 are mounted in accordance with the wiring pattern of the wiring board, the wiring pattern is determined. After generating a plurality of line segment aggregates composed of the mount positions by connecting between the mount positions closest to each of the mount positions, the mount closest to the line segment aggregate closest to each of the line segment aggregates The positions are connected to each other until one line segment aggregate is formed, and the shortest is performed while the connection is rearranged so that the mounting position connected at three or more positions is connected to the other two or one other mounting position. By continuously selecting the path and connecting all the mounting positions as one shortest path, the head unit 19 moves during the mounting operation for each of the mounting units 6 to 8. You can search the shortest path, thus efficiently and in a relatively short time it is possible to find the shortest path.

(5) Other Embodiments In the above embodiment, the CAD terminal 2 sets coordinate data for each reference number assigned to each wiring board, and sets the polarity and through-hole of each wiring board. After setting the pitch, the case where the pitch is supplied as the CAD data S1 to the board manufacturing unit 3 and the work station 4 has been described. However, the present invention is not limited to this. (Digiti
zer) or a tablet, and the operator may input coordinate data based on the detection result.

In the above embodiment, the shortest path search method according to the present invention is applied to the CAM system 1 for designing and manufacturing a wiring board by using various electronic components assigned to each of the mounting units 6 to 8. The case where the algorithm is applied when creating an algorithm for mounting the corresponding wiring pattern with the shortest path in the shortest path has been described. However, the present invention is not limited to this, and may be applied to an automatic path search in navigation other than the mounting apparatus. In addition, the present invention is suitable for being widely applied to various electronic devices in which it is difficult to increase the operation amount of the CPU. Further, the plurality of points constituting the shortest path may be arranged not only two-dimensionally but also three-dimensionally.

[0040]

As described above, according to the present invention, in a shortest path search method for searching for a shortest path among paths passing through a plurality of given points, a shortest path is searched for each of a plurality of points. A single aggregate that connects multiple aggregates by connecting the closest points to the nearest aggregate for each aggregate after connecting and generating multiple aggregates consisting of the points And for each point that produces the single aggregate, select the shortest path while rearranging the connections so that the point is connected to the other two or one other point. Continuously connecting all points as one shortest path, the amount of calculation can be significantly reduced compared to the case of calculating the combination of all points and searching for the shortest path Thus efficient and relatively short time can search the shortest path.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the overall configuration of a CAM system according to an embodiment.

FIG. 2 is a schematic perspective view showing an external configuration of each mounting unit according to the embodiment.

FIG. 3 is a flowchart for explaining a shortest path search processing procedure;

FIG. 4 is a plan view for explaining an algorithm for searching for the shortest route.

FIG. 5 is a plan view for explaining an algorithm for searching for the shortest route.

FIG. 6 is a plan view for explaining an algorithm for searching for the shortest route.

FIG. 7 is a plan view for explaining an algorithm for searching for the shortest route.

FIG. 8 is a flowchart for explaining a procedure for determining a mounting order;

FIG. 9 is a plan view for explaining an algorithm for determining a mounting order.

[Explanation of symbols]

1 ... CAM system, 2 ... CAD terminal, 3 ... board manufacturing unit, 4 ... work station, 5 ... mounting device,
6... First mounting section, 7... Second mounting section, 8.
Mounting part, 9 ... hand mounting part, 10 ... DIP part, 1
8: Parts supply table, 19: Head unit, P
WB: Wiring board, EC: Electronic component, D: Screen, P
1 to P10: Mount position (point), C1 to C
3, CA: line segment aggregate (aggregate), M1 to M3: shortest path.

Claims (4)

[Claims] 1. A shortest path search method for searching for a shortest path among paths passing through a plurality of given points, the method comprising: connecting a point closest to each of the plurality of points to a plurality of points; By connecting the closest points between the first step of generating the aggregates of the above and the nearest aggregate for each of the above aggregates, a single aggregate connecting the plurality of aggregates is formed. A second step to generate, and for each of the points to generate the single aggregate, re-arranging the connection such that the point is connected to another two or one other point. A third step of continuously selecting a short path and connecting all the points as one shortest path. 2. In a third step, the connection is rearranged so that a point connected to three or more other points is connected to another two or one other point. 2. The shortest route search method according to claim 1, wherein when there are a plurality of newly generated routes centered on the points connected by the recombination, the shortest route is selected. 3. In the third step, when at least one of the three or more points connected to the point connected by the recombination is a terminal point, the recombination target is set. 3. The shortest path search method according to claim 2, wherein the point is switched to another point. 4. When there are a plurality of the shortest paths provided by the third step, after searching for a point at one end of the shortest path closest to a predetermined starting point among the shortest paths, the search is performed. Based on the shortest path including the shortest path, by continuing to connect the points at the one end or the other end closest to each of the shortest paths in succession,
The shortest path search method according to claim 1, wherein all the shortest paths are connected as one shortest path.