JP2607694B2 - CAD system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] A CAD system for determining the shortest route of a wiring route on a printed circuit board in a CAD system, which aims to speed up the search for the shortest route from a starting point to a destination point. According to the present invention, there is provided a CAD system for obtaining a route connecting a current position and a target position, the direction calculating means for obtaining a priority order of a direction to be advanced based on the coordinates of the current position and the coordinates of the target position, From the coordinate points around the position,
A coordinate point moving unit that sets a coordinate point having no obstacle based on the priority order as a coordinate of a next current position.

[Industrial applications]

The present invention relates to a CAD system for searching for and determining the shortest route of a wiring path on a printed circuit board in a CAD system.

In recent years, as semiconductor devices have become higher in density and larger in scale, circuit design using the same has become more complicated. Therefore, CAD (computer ai) that performs the design work while confirming the process of the design by computer simulation
ded design) system is evolving.

An important point in CAD systems is the determination of wiring routes on printed circuit boards. That is, the wiring paths connecting the elements are processed in accordance with a predetermined rule. However, the determination of the wiring section and the determination of the wiring path are important processes. For this reason, various wiring algorithms have been proposed for determining the wiring path. ing. A typical wiring algorithm is the “Lee” algorithm described later.

[Conventional technology]

FIG. 8 shows a method of determining a wiring route by the "Lee" algorithm.

In the figure, S is a starting point, T is a destination point, and hatched portions are obstacles. In this method, the search for the wiring route is performed as follows.
That is, "1" is written in all the "sky" grids adjacent to the starting point S. Next, “2” is written to all “sky” grids adjacent to “1”. In this way,
When the destination point T is reached, a route can be found between ST and ST. And
The shortest route between S and T can be determined by reversing the entered numbers.

[Problems to be solved by the invention]

FIGS. 9 and 10 are diagrams for explaining a conventional problem. In the above-described method, the numbers are filled in all the adjacent “empty” grids, and thus the numbers are also written in the grids in the direction completely opposite to the destination point. Also, the final result can be determined only when there is no “empty” grid in which numbers can be entered.

Therefore, as shown in FIG. 9, even when the route is clearly known, the route does not go straight from the starting point S toward the destination point T. Until the numbers are entered in the "empty" grid adjacent to the destination point, the numbers must be filled into the grid in the exact opposite direction.

Further, as shown in FIG. 10, even when there is no wiring route, it cannot be determined that the numbers are not entered in all the “empty” grids.

As described above, the conventional method requires an enormous amount of time for the process of determining the wiring route.

An object of the present invention is to provide a CAD system capable of speeding up the search and determination of the shortest route from a starting point to a destination point.

[Means for solving the problem]

 FIG. 1 is a diagram illustrating the principle of the present invention.

According to the present invention, there is provided a CAD system for obtaining a route connecting a current position and a target position, the direction calculating means for obtaining a priority order of a direction to be advanced based on the coordinates of the current position and the coordinates of the target position, From the coordinate points around the position,
A coordinate point moving unit that sets a coordinate point having no obstacle based on the priority order as a coordinate of a next current position.

(Operation)

In the present invention, a route connecting the two points is determined without first determining whether there is an obstacle between the starting point and the destination point, and if there is an obstacle on the route, the current A priority order is set in a direction from the position to the destination point, and a route connecting the starting point and the destination point is determined by sequentially moving the current position so that a point without an obstacle is directed to the destination point according to the priority order. .

Also, without first determining whether there is an obstacle between the starting point and the destination point, a route connecting the two points is determined, and if there is an obstacle on the route, the route of the obstacle is determined. Find a point, number the grid adjacent to the starting point and clear of obstacles, and then number the grid adjacent to the numbered grid and clear of obstacles, When the points are numbered, a route connecting the starting point and the destination point is determined by sequentially following the numbers assigned to the grid from the destination point to the starting point (Lee's algorithm).

〔Example〕

2 and 3 are basic wiring route determination patterns according to the present invention. The simplest case can be determined by these basic wiring route determination patterns.

FIG. 2 shows a first wiring route determination pattern, in which a destination point T is shown in a straight line with respect to a starting point S. There are eight directions, and two points having a small X component of grid coordinates are defined as starting points. The larger number is the target point, and the number of grids in the X direction (ΔX) and the number of grids in the Y direction (ΔY) between the two points are determined.

In this case, ΔX = 0 or ΔY = 0 or | ΔX | = | ΔY | is the basis for using the route of this diagram, and ΔX = 0 or Δ
If Y = 0, it indicates the vertical and horizontal directions in FIG. 2, and | ΔX |
= | ΔY | indicates four oblique directions of 45 degrees.
As long as there are no obstacles on the way, there is a single line from the starting point to the destination point.

FIG. 3 shows a second wiring route determination pattern, which is indicated by a vertical or horizontal direction of +45 degrees (route 1), or a case of 45 degrees and a vertical or horizontal direction (route 2).

If the basic route determination pattern cannot be determined using the above-described basic wiring route determination pattern, the wiring route is determined using a direction determination pattern described later with the following FIG. 4 as the basic search direction.

FIG. 4 shows the basic pattern of the direction search, and
3 If the direction cannot be determined in Fig.
The direction is determined by a direction determination pattern described later. That is, the above eight directions are applied to the following basic patterns.

Determining pattern of departure direction from starting point When ΔX = 0, ΔY> 0, search in order of 2 → 4 → 3 → 1 → 5 When ΔX = 0, ΔY <0, 8 → 6 → 7 → 1 → Search in the order of 5 When ΔY = 0, search in the order of 2 → 8 → 1 → 3 → 7 ΔX ≧ | ΔY |, When ΔY> 0, search in the order of 2 → 3 → 1 → 8 → 4 ΔX When ≧ | ΔY |, ΔY <0, search in the order of 8 → 7 → 1 → 6 → 2. When ΔX ≦ | ΔY |, ΔY> 0, search in the order of 2 → 1 → 3 → 8 → 4 ΔX When ≦ | ΔY |, ΔY <0, search in the order of 8 → 1 → 7 → 6 → 2 These seven patterns are stored in the first table.

Next, the direction change after departure is performed according to the following basic pattern.

Determining pattern of change direction after departure | ΔX |> | ΔY |, ΔX> 0, change direction = 1, travel amount = || ΔX | − | ΔY || | ΔX |> | ΔY |, ΔX <0 , Change direction = 5, travel amount = || ΔX | − | ΔY ||| ΔX |, ΔY> 0, change direction = 3, travel amount = || ΔX | − | ΔY | | | ΔY |> | ΔX |, ΔY <0, change direction = 7, travel amount = || ΔX | − | ΔY || | ΔX | = | ΔY |, ΔX> 0, ΔY> 0, When the change direction = 2, the movement amount = | ΔX || ΔX | = | ΔY |, ΔX> 0, ΔY <0, the change direction = 8, the movement amount = | ΔX || ΔX | = | ΔY |, ΔX < 0, ΔY <0, change direction = 6, travel amount = | ΔX | | ΔX | = | ΔY |, and ΔX <0, ΔY> 0, change direction = 4, travel amount = | ΔX | The change direction indicates the priority direction at this point, and the movement amount indicates the movement amount to be advanced in that direction.

 These eight patterns are stored in the second table.

Next, a basic pattern of a direction change when the vehicle collides with an obstacle will be described.

Determining pattern of change direction when hitting obstacle Obstruction = 1, ΔY> 0 Change direction = current direction + (1 → 2 → −1) forward direction = 1, ΔY <0 Change direction = Current direction + (-1 → -2 → 1) forward direction = 2, when | ΔX | ≧ | ΔY |, change direction = current direction + (-1 → -2 → 1) forward direction = 2, When | ΔX | <| ΔY |, change direction = current direction + (1 → 2 → −1) forward direction = 3, when ΔX ≧ 0, change direction = current direction + (− 1 → −2 → 1) ) Forward direction = 3, when ΔX <0, change direction = current direction + (1 → 2 → −1) forward direction = 4, when | ΔX | ≧ | ΔY |, change direction = current direction + ( 1 → 2 → −1) forward direction = 4, when | ΔX | <| ΔY |, change direction = current direction + (− 1 → −2 → 1) forward direction = 5, when ΔY ≧ 0, Change direction = current direction + (− 1 → −2 → 1) forward direction = 5, When ΔY <0, change direction = current direction + (1 → 2 → −1) forward direction = 6, when | ΔX | ≧ | ΔY |, change direction = current direction + (− 1 → −2 → 1) ) Forward direction = 6, when | ΔX | <| ΔY |, change direction = current direction + (1 → 2 → −1) forward direction = 7, when ΔX ≧ 0, change direction = current direction + ( 1 → 2 → −1) forward direction = 7, ΔX <0, change direction = current direction + (− 1 → −2 → 1) forward direction = 8, | ΔX | ≧ | ΔY | Change direction = current direction + forward direction of (1 → 2 → -1) Direction = 8, when | ΔX | <| ΔY |, change direction = current direction + (-1 → 2 → 1) order, where direction = 0, direction = 8, direction = -1, direction = 7, direction = 9, direction = 1, direction = 10, direction = 2. If all three directions cannot be moved, it is determined that there is no route. .

 These 16 patterns are stored in the third table.

After determining the departure direction, Δ between the current position on the grid and the destination point
The search direction and the amount of movement are obtained from X and ΔY, and the search direction is checked and the grid is moved. If the vehicle collides with an obstacle while moving, the direction is changed to an optimal direction, and after the direction is changed, the search direction and the moving amount are obtained again from ΔX and ΔY between the point and the target point.
By continuing this processing, it is possible to reach the target point.

FIGS. 5 and 6 are flowcharts of one embodiment of the present invention.

FIG. 5 shows a case where the pattern matches the basic wiring route determination pattern shown in FIGS.

In FIG. 5, first, grid coordinates of a starting point and a destination point are obtained (1). The X coordinate of the starting point is compared with the X coordinate of the destination point (2). Here, it is assumed that the processing direction proceeds from left to right. When the X coordinate of the starting point is larger than the X coordinate of the destination point, the starting point and the destination point are exchanged (3). When the X coordinate of the starting point is smaller than the X coordinate of the destination point, the difference between the X coordinate of the starting point and the X coordinate of the destination point (ΔX) and the difference between the Y coordinate of the starting point and the Y coordinate of the destination point (ΔY) are calculated. Ask (4). As a result, ΔX = 0 or ΔY = 0 or | ΔX | =
It is determined whether or not | ΔY | (5). If any of these conditions is satisfied, it indicates the up / down / left / right direction or the diagonal four directions and matches the pattern of FIG. 2, and the starting point and the destination point are 1
They are connected by a main line (6).

If none of these matches, it is next determined whether or not the pattern of FIG. 3 is matched. First, it is determined whether or not the route 1 can be connected by two vertical or horizontal + diagonal lines (7). ), Otherwise, it is determined whether or not the two lines can be connected diagonally + vertically or horizontally (8). If it is not the above-mentioned steps 6, 7, and 8, the process proceeds to the flowchart of FIG. In Steps 6, 7, and 8, when the connection can be made by one line, and when the connection can be made by two lines, the search can be performed in FIGS. 2 and 3 (9), and the search is performed.

2 and 3 are processing flowcharts for determining a wiring route by referring to the first, second, and third tables when a search cannot be performed. FIG. 7 is an example of the processing of FIG.

First, with reference to the first table for determining the departure direction, the departure direction is determined from the already obtained ΔX and ΔY (1). Next, it advances by "1" (one grid) in the determined direction (2). Using the coordinate difference (ΔX, ΔY) between the current position and the destination point, referring to the second table, calculate the change direction that is the direction to go and the maximum movement amount that can go in that direction, and go forward. It advances one by one until the maximum movement amount is reached in the power direction (change direction) (5). By proceeding this movement, it is determined whether the vehicle has reached the target point (6). If it has not arrived, it is next determined whether it has hit an obstacle (7). Referring to the third table when the object collides, the direction is changed from ΔX and ΔY between the position immediately before the object collides with the obstacle and the target point (8). Then, it is determined whether or not the direction can be changed (9), and if it can be changed, the process proceeds by "1" in the changed direction (10).

Hereinafter, this procedure is repeated from step 3 to determine the wiring route to the target point. Note that the search is terminated when the target point is reached in step 6 (11).
If the departure direction cannot be determined or the direction cannot be changed in steps 1, 4, and 9, search cannot be performed (12), and the process ends.

FIG. 7 is an example of determining a wiring route. As shown in the figure, starting from the diagram (a), the wiring route is determined in the diagram (d). In the figure, S is a starting point, T is a destination point, a hatched portion is an obstacle, and a scattered portion is another obstacle.

In (a), ΔX = 5 (X coordinate 7 of destination point−X coordinate 2 of starting point),
From ΔY = 4 (Y coordinate of destination point−Y coordinate 1 of starting point), the departure direction is 2 → 3 → 1 with reference to the first table.
→ 8 → 4. Referring to FIG. 4, the direction 2 of the coordinates (3, 2) cannot be advanced because there is an obstacle. The direction 3 of the coordinates (2, 2) cannot be advanced because there is an obstacle. The direction 1 of the coordinates (3,1) can proceed because there is no obstacle, and the departure direction is determined in this direction.

The current position is described above, and the coordinates are ΔX = 4, ΔY
Since = 4, the direction is 2 and the moving amount is ΔX (= 4) with reference to the second table storing the change direction.
However, the coordinates (4, 2) in the direction of “2” in FIG. 4 cannot be advanced because there is an obstacle, and the direction change when there is an obstacle is performed in the third direction.
This is performed using the table.

The current direction is 2, ΔX = 4, ΔY = 4, and the change direction is
Referring to the third table, the current direction + (-1 or-
Search in the order of 2 or 1). Since the direction 2-1 has no obstacle, the conversion direction is determined and becomes the coordinate (4, 1).

In (b), ΔX = 3 and ΔY = 4 at the current position.
Is 3 and the moving amount is ΔY
− | ΔX | However, since there is an obstacle at the coordinates (4, 2), the direction is changed without proceeding.

Since the current direction is 3, ΔX = 3, and ΔY = 4, the change direction in the third table is searched in the current direction + (− 1 or −2 or 1). The direction 3-1 cannot be advanced because there is an obstacle. The direction 3-2 can be advanced because there is no obstacle, and the change direction is determined at the coordinates (5, 1).

At the current position, since ΔX = 2 and ΔY = 4, the direction is 3 from the second table, the movement amount is 2, but there is another obstacle at the coordinates (5, 3). Five,
2) and change direction.

In (c), since the current direction is 3, ΔX = 2, and ΔY = 3, the change direction of the third table is the current direction +
(-1 or -2 or 1).

The direction 3-1 has no obstacles, so the change direction is represented by coordinates (6,
Decide in 3).

Since the current position is at coordinates (6,3), ΔX = 1, Δ
Since Y = 2, referring to the second table, the direction is 3, the moving amount is 1, but the direction is changed because there is another obstacle at the coordinates (6, 4).

Since the current direction is 3, ΔX = 1, and ΔY = 2, the change direction is the current direction + (− 1, −2, or 1) with reference to the third table. The direction 3-1 does not proceed because there is another obstacle.
In the direction 3-2, since there is no obstacle, the direction 3-2 moves to the coordinates (7, 3). In (d), the current position is represented by coordinates (7,
Since ΔX = 0 and ΔY = 2, the direction is 3 and the moving amount is 2 with reference to the second table. However, since the coordinates (7, 3) and (7, 4) have different shared grids, the direction is changed.

The current direction is 3, and the change direction is the current direction + (− 1 or −2 or 1) from ΔX = 0 and ΔY = 2. Since the direction 3-1 has no obstacle, the change direction is determined to the coordinates (8, 4).

Then, since ΔX = −1 and ΔY = 1, the direction is 4 and the moving amount is 1 from the second table, and the target point T is reached.

〔The invention's effect〕

As described above, in the present invention, the grid to be checked is only the grid in the search direction, and since the departure direction and the change direction have a starting point in advance, the determination is fast, and when there is no direction that can be changed, Since there is no path, the processing time can be greatly reduced. Further, since the distance to the destination point is always reduced in the route change direction, it is possible to search with the shortest route.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention, FIG. 2 is a first wiring path determination pattern, FIG. 3 is a second wiring path determination pattern, FIG. 4 is a direction search pattern, FIG. FIG. 6 is a flowchart of an embodiment based on the second wiring route determination pattern, FIG. 6 is a flowchart of an embodiment of wiring route determination based on the first, second, and third tables, and FIGS. 7 (a) to (d) are flowcharts of FIG. An example of the procedure from the starting point to the destination based on the algorithm, FIG. 8 is an explanatory diagram of the "Lee" algorithm, and FIGS. 9 and 10 are explanatory diagrams of the conventional problems. (Explanation of reference numerals) 1... Wiring route determination pattern, 2... Search table, 3... 1st table, 4... 2nd table, 5.

Claims (1)

(57) [Claims] 1. A CAD system for obtaining a route connecting a current position and a target position, wherein the route determining means obtains a route connecting the current position and the target position based on a coordinate difference between the current position and the target position and a predetermined pattern. And determining means for determining whether there is an obstacle on the route determined by the route determining means; and determining that there is an obstacle on the route determined by the determining means, Direction calculating means for obtaining a priority order of a direction to be traveled based on the coordinates of the destination position; and, among coordinate points around the current position, a coordinate point having no obstacle based on the priority order. A CAD system comprising: a coordinate point moving unit that sets coordinates of (1) and (2).