JPH05246193A - Figure drawing apparatus - Google Patents

Abstract

PURPOSE:To reduce the operation cost and figure drawing cost of the title apparatus by drawing a figure in the order corresponding to drawing positional relation so that the moving distance of the pen plotter of a CAD device having a plotter becomes shortest. CONSTITUTION:The passing point calculating means 121 of an operational processing part 12 calculates the coordinates of the middle point of a 'draw' terminal point as a temporary passing point where the pen cursor of a plotter 2 passes on a figure from the figure data stored in a figure data file 11 to calculate the shortest route on the basis of said coordinates. A drawing sequence determining means 122 operates the 'move' distances when the pen cursor moves in forward and reverse directions according to the shortest route and a drawing sequence of a shorter 'move' distance is selected. A sequence data output part 13 gives 'draw' and 'move' orders to the plotter 2 according to the selected drawing sequence.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention includes a pen plotter.
The present invention relates to a graphic drawing device such as a laser processing machine for computer-controlled movement of a CAD device, a processing head, and a processing table.

[0002]

2. Description of the Related Art In a conventional CAD device, when drawing a plurality of figures with a pen plotter, the figure data input order in CAD or the attribute data for drawing each figure such as the start / end and center angle of a line The output order of the graphic data to the pen plotter is determined according to the data storage order in the stored graphic data file.

[0003]

SUMMARY OF THE INVENTION The conventional graphic drawing apparatus as described above penforms graphic data in a drawing order that is irrelevant to the drawing positional relationship, such as the input order of graphic data and the storage order of data in a graphic data file. Since the drawing means such as the plotter, the processing head, and the processing table are output, the movement of the drawing means is wasted, and it takes a long time to draw a figure, and the drawing means wears quickly and shortens the life of the apparatus. There is a problem that the operating cost and drawing cost of the device increase.

The present invention has been made in order to solve such a problem, and moves the drawing means in accordance with the drawing order in consideration of the drawing position relationship of each figure, and eliminates unnecessary movement of the drawing means. It is an object of the present invention to provide a graphic drawing apparatus that reduces the operating cost and drawing cost of the apparatus by shortening the drawing time as much as possible and extending the life of the apparatus.

[0005]

In a graphic drawing apparatus according to the present invention, a drawing means which is moved to draw a graphic is moved in a predetermined drawing order so that a plurality of graphics are attribute data for drawing each graphic. A device for drawing based on the attribute data, a means for obtaining a representative coordinate representative of the drawing position of each figure, and a means for obtaining the shortest distance route among the routes each passing through each representative coordinate once. According to the route obtained by the means, means for calculating a moving distance of the drawing means in a non-drawing period between figures and determining a drawing order in which the moving distance is the shortest is provided.

[0006]

The graphic drawing apparatus according to the present invention obtains the representative coordinates representative of the drawing position of each figure based on the drawing attribute data of each figure, and determines the shortest route among the paths which pass through the representative coordinates once. The path of distance is obtained, and the drawing order that minimizes the distance that the drawing means moves in the non-drawing period between the figures is determined according to this shortest path.

[0007]

The present invention will be described below with reference to the drawings showing the embodiments thereof. FIG. 1 is a block diagram showing the configuration of a CAD device according to the present invention. In the figure, reference numeral 1 is a CAD that determines the drawing order by creating figure data including attribute data for drawing each figure data from the figure created on the screen. Output to plotter 2.

Various parameters such as the coordinate values of the starting point, the ending point, the center of a circle, etc. of the straight line which are the attribute data on the drawing of the figure created by CAD 1 are stored in the figure data file 11, In the arithmetic processing unit 12, the passing point calculating means
Based on the graphic data stored in the graphic data file 11, 121 calculates the representative coordinate value which is the midpoint between the two drawing end points of the drawing start end and the end of each drawing as a temporary passing point of the pen cursor in each graphic. Based on this representative coordinate value, the drawing order determining means 122 finds the shortest path that passes each passing point once, by the method described later, and according to this shortest path, the pen cursor in the non-drawing period between figures in the plotter 2. Is calculated to determine the drawing order in which the moving distance becomes the shortest distance, and the data output unit 13 sequentially gives draw, move commands to the plotter 2 in accordance with the determined drawing order.

A graphic drawing procedure performed by the CAD apparatus having the above-described structure will be described with reference to the flowchart shown in FIG. In this embodiment, the number of figures is (n-1). As a temporary passing point where the pen cursor passes through each figure, the coordinate values of the midpoints of the two draw end points of each figure are obtained, and the n passing points obtained by adding one point of the home position Pn of the pen cursor Ask (S1). The shortest path of the paths through which the pen cursor passes once each of the temporary passing points of the pen cursor is obtained by the method described later (S2).

The pass order of the forward path is obtained from this shortest path, and the move distance of the pen cursor from one of the two draw end points of the first figure to the draw end point close to the origin home position Pn. Is calculated, and then two dr of the second figure from the other draw end point of the first figure
Of the aw endpoints, add up the distance to the closest draw endpoint,
Home position P while incrementing the passing order
The above operation is repeated n times until it returns to n, and the move distance of the pen cursor in the forward path of the draw end point is obtained (S3).

Next, from the home position Pn, to the home position Pn on the forward draw path, whichever is closer to the draw end point of the two draw end points of the (n-1) th figure in which the forward path passes. It is detected whether or not the draw end points immediately before returning are the same end point (S4), and if they are the same, the move distance on the backward route is the same as the value accumulated on the forward route, so the process jumps to step S8.

On the other hand, as a result of the step S4, when the draw end points are not the same, of the two draw end points of the (n-1) th figure, from the home position Pn to the closer draw end point.
Calculate the move distance, then draw the (n-1) th other
The move distance from the end point to the draw end point of the closer (n-2) th graphic element is added up, and the above operation is repeated n times while decrementing the passing order in the reverse order of the forward direction path, and the backward path Find the move distance of the pen cursor at (S5).

Accumulated move in forward and backward paths
Compare the distances (S6). If the value of the forward route is small, draw, mov according to the drawing order when the forward route move distance is integrated.
The e command is output to the plotter 2 (S7), and if the value of the backward route is small, the draw, move command is output to the plotter 2 according to the drawing order when the backward route move distance is integrated (S8). When the reverse route is selected, the passing order is changed to the reverse order.

Next, the procedure for obtaining the shortest route in step S2 will be described. In this embodiment, a method of solving the traveling salesman problem by introducing a Hopfield network is applied.

FIG. 3 shows passing points 1, 2, ..., X, y ,.
n is a row, and the order of passage is 1, 2, ..., I, j ,.
Of n ² columns, each element of the matrix has a state of “1” or “0”, and in the case of “1”, the passing point of the corresponding row is passed in the order of the corresponding column. When the value is “0”, it means that the signal does not pass. Further, in this matrix, it is desirable that the same passing point does not pass more than once, that is, two or more points in each row and each column of the matrix do not have the state of "1".

In such a matrix of passing points and passing orders,
Apply Hopfield networks. That is, the energy function (cost evaluation function) is stochastically reduced by the Hopfield network, and the pattern of "1" and "0" when the energy function becomes the minimum is obtained to obtain the approximate optimal solution of the traveling salesman problem. That is, the shortest route in this embodiment is obtained. The energy of the network proposed by Hopfield is expressed by the following equation.

[0017]

[Equation 1]

Where E (t) is the energy of the network at the time t, Wlm is the coupling strength coefficient between the unit 1 and the unit m, and Vl (t) and Vm (t) are the time t of the units 1 and m, respectively. The output value at, θl is the threshold of unit l.

The equation (1) is rewritten by applying it to the matrix consisting of combinations of passing points and passing orders shown in FIG. The unit at the x-th row and the i-th column is represented by xi, and the unit at the y-th row and the j-th column is represented by yj. Further, the values in the following formulas are values at time t.

[0020]

[Equation 2]

However, Wxi, yj is a unit xi and a unit
Coupling strength coefficient between yj, Vxi, Vyj are output values of the unit xi, yj, and θxi is a threshold value of the unit xi.

The total sum Uxi (t) of the signals received by the unit xi from other units at the time t is given by the following equation.

[0023]

[Equation 3]

The energy function generally has a large number of local minima, and when it is applied to an optimization problem, it takes a long time to reach the vicinity of the minimum value by being trapped in the local minima, so the stochastic method using the Monte Carlo method is used. It is effective to introduce simulated annealing that escapes from the local optimum value of the energy function by introducing fluctuations and converges to a more optimum state, that is, the minimum value.

When the magnitude of the fluctuation of probability is defined by "temperature", the value Vxi (t +) output at the next time t + 1 by the unit xi which has received the signal whose sum is Uxi (t) at time t 1)
Can be obtained by the following procedure.

[0026]

[Equation 4]

However, T (t) is the temperature of the network at time t, and Ts is the initial temperature of T (0).

[0028]

[Equation 5]

However, in Jxi, the state of the unit xi is "1".
It is a value for judgment indicating a probability distribution of. if (rand (1) ≦ Jxi) Vxi (t + 1) = 1 else Vxi (t + 1) = 0 (6) However, rand (1) represents a uniformly distributed random number of 0 to 1.

The cost evaluation function that reflects the length of the route is determined as follows. _{Ec = E 1 + E 2 ...} (7) however, ec is the evaluation value, E ₁ is an evaluation value sum of each path associated with one path.

[0031]

[Equation 6]

Where dxy is the distance from Px to Py,
(DxyVxiVy, i + 1) is the i-th P and the (i + 1) -th P
The evaluation value of the route that passed y, similarly (dxyVxiVy, i-
1) is an evaluation value of a route that has passed (i-1) th and Py, and ithly, and E ₁ is related to the total movement distance, and is preferably the smallest.

Further, in the equation (7), E ₂ is a correction term added so that the evaluation value of the network corresponding to the nonsense route becomes large.

[0034]

[Equation 7]

The first term of the equation (9) is a term which becomes "A" when the unit output values of the two columns i and j in the same row x of the matrix expression are "1" at the same time, and the same point is 2 It has the role of preventing the passage of two times (mutual suppression effect between accompanying elements). Second
Similarly, the term is a term that becomes “B” when the unit output values of two rows x and y in the same column i are “1” at the same time, and has a role of preventing the same point from passing twice ( Mutual suppression effect between elements in the same row). In the third term, the sum of matrix elements is n
^When it deviates from ² , it is a term that increases the evaluation value according to the deviation, and has a role of limiting the number of all passing points to n ² .

The above equation (2) monotonically decreases while continuing to change the state, but it is unknown whether the cost evaluation function represented by the equations (7) to (9) monotonically decreases. And (7) ~ (9)
It suffices if the equations are overlapped, that is, Ec (t) has a decreasing property as t increases.

Wxi, yj = -Afxy (1-fij) -B (1-fxy) -C-Ddxy (fj, i + 1 + fj, i-1) (10) θxi = Cn (11)

However, fij is a Kronecker delta and is defined by if i = j fij = 1 else fij = 0.

A specific example of obtaining the shortest path when drawing the three graphic elements, the arc (A), and the straight line (B) (C) of FIG. 4 using the above procedure will be described below. The home position of the pen cursor is the origin (0,0). Fig. 5 shows the figure data file, which is used for various types of figures, such as coordinate values and radiuses of straight line start and end points, circle center, etc., and various parameters such as arc center angle, and figure data when creating figures using CAD. The input order is stored.

In the present embodiment, the arc (A) is represented by the center coordinates (6,5),
Radius 2, central angle 90 ° to 270 °, straight line (B) is the starting point coordinates (15,
3), the end point coordinates (16,1) and the straight line (C) are the start point coordinates (13,9) and the end point coordinates (9,1). The draw end points of the graphic elements (A), (B), and (C) are Aa, Ab, Ba, Bb, Ca, and Cb, and the temporary passing points are Ac, Bc, and Cc.

For comparison, when the input order is followed in the conventional graphic drawing apparatus, (0,0) → Cb → Ca → Aa → Ab → Ba → Bb →
The pen plotter moves along the path of (0,0), and (0,0) ~ Cb, Ca ~
The total move distance of Aa, Ab ~ Ba, Bb ~ (0,0) is 41.84.

Further, in the case of following the registration order in the conventional graphic drawing device, (0,0) → Aa → Ab → Ba → Bb → Cb → Ca → (0,0)
The pen plotter moves along the path of (0,0) ~ Aa, Ab ~ Ba, Bb
The total move distance of ~ Cb, Ca ~ (0,0) is 41.55.

In this embodiment, first, two drs of the arc (A) are
aw The end points Aa (6,7) and Ab (6,3) are found using trigonometric functions, and the passing points Ac (6,5) are found. The straight line (B) is the end point Ba (15,3), Bb (16,
1) to Bc (15.5, 2), straight line (C) is endpoint Ca (13,9), endpoint C
Find Cc (11, 5) from b (9, 1). Four passing points are obtained by adding (0,0) of home position (0) to Ac, Bc, Cc.

The shortest path of the pattern represented by the following matrix is obtained according to the procedure described above.

Forward path, P ₁ (0,0) to P ₂ · Ab (6,3)
_{→ Aa (6,7) ~P 4 ·} Cb (9,1) → Ca (13,9) ~P 3 · Bb (15,
3) → Ba (16,1) to P ₁ (0,0) is calculated.

Next, draw of P ₃ closer to P ₁ (0,0)
Since the end point is Bb (15,3) and is different from the final end point Ba of the forward path, there is a backward path. Reverse path, P ₁ (0,0) to P
₃・ Bb (15,3) → Ba (16,1) 〜P ₄・ Cb (9,1) → Ca (13,9) 〜
P ₂ · Aa (6,7) → Ab (6,3) to P ₁ (0,0) are calculated.

Based on the forward path and the backward path, the move distance x of the pen cursor between the figures is calculated by the following formula and integrated. Where (x ₁ y ₁ ) is the move start point, and (x ₂ , y ₂ )
Indicates the end of move. _{x = √ {(x 1 -x} 2) 2 + (y 1 -y 2) 2} ... (12)

As a result, in the present embodiment, the mo
Since the ve distance is shorter, the reverse route is adopted, and the figure data is sequentially output to the plotter according to the drawing order when the move distance is integrated.

As described above, in the present embodiment, the coordinates of the midpoint of the draw end point are used as the temporary passing point of the pen cursor, whereby the shortest path is calculated quickly, and therefore the drawing order of the figures can be obtained quickly. Further, since the temporary passing point is set by the representative coordinate values of the figure, the calculation scale of the shortest route can be suppressed to a small value.

Although the CAD device has been described in the present embodiment, a graphic drawing device in which the moving cost of the drawing means such as a laser processing machine for moving the welding / melting stage processing head or the processing table (positioner) to the computer is relatively high. It may be.

Further, in the present embodiment, the case where the shortest path is obtained at once for all the figures has been described. However, in the case of a huge amount of figures, the whole is divided into a plurality of blocks and the shortest path is set for each block. May be asked. At this time, the home position only needs to be considered in the first block and the last block, and it is not necessary to consider the home position in other blocks.

[0052]

As described above, since the figure drawing apparatus according to the present invention draws the figures in the drawing order in consideration of the drawing positional relationship of the figures, the movement distance of the drawing means such as the pen cursor and the machining head is substantially the same. This is the shortest, the wear of the drawing means is small, the life of the apparatus is extended, and the operation cost of the apparatus and the drawing cost are significantly reduced, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a block diagram of a CAD device according to the present invention.

FIG. 2 is a flowchart showing a graphic drawing procedure of the CAD device according to the present invention.

FIG. 3 is a diagram illustrating a principle of obtaining a shortest path.

FIG. 4 is a diagram showing a drawing positional relationship between figures.

FIG. 5 is a conceptual diagram of a data storage state of a graphic data file.

[Explanation of symbols]

 1 CAD 2 Plotter 11 Graphic Data File 12 Arithmetic Processing Unit 13 Sequential Data Output Unit 121 Passing Point Calculation Means 122 Drawing Order Determining Means

Claims (1)

[Claims] 1. An apparatus for drawing a plurality of figures based on attribute data on drawing of each figure by moving a drawing means moved to draw a figure in a predetermined drawing order, based on the attribute data. , A means for obtaining a representative coordinate representing the drawing position of each figure, a means for obtaining the shortest path among the paths each passing through each representative coordinate once, and non-drawing between figures according to the path obtained by the means A graphic drawing apparatus, comprising: means for calculating a moving distance of the drawing means during a period and determining a drawing order in which the moving distance becomes shortest.