JP2005135348A - Parameter real length development device, method, and program therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a parameter real length development device, a method, and a program therefor which permit highly accurate development work by limiting a development error that occurs for developing a target shape into member shapes. <P>SOLUTION: The target shape in a real space generated by predetermined graphic representation is mapped into a parameter space defined by tangent vectors forming a tangential plane of the target shape, the parameter space coordinate value of the mapped target shape is set as a parameter space coordinate value of the member shape for which the target shape is developed to calculate a real space coordinate value corresponding to the parameter space coordinate value of the member shape, and on the basis of the calculated real shape coordinate value of the member shape, distances between corresponding points between the target shape and the member shape are calculated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a parameter actual length developing apparatus and method for developing a target shape into a member shape, and a program thereof.

Conventionally, “actual length expansion” is an actual length expansion method in an operation for expanding a hull shape into a steel plate (flat plate) as a material (hereinafter referred to as current drawing expansion). According to this method, the position in the case where the target ship shape is developed into the member shape is determined by obtaining the vertex based on the actual length of the triangle. Specifically, first create a triangle on the body plan, determine the line diagonally, and find the actual length. Similarly, the actual length of the frame is obtained by measuring the body plan. Then, the vertex of the triangle is obtained using the actual length of the frame, the actual length of the task, and the actual length of the seam. As described above, the position of the vertex is calculated based on the actual length of the triangle.
The base line of this development is set at the central part, and the base line is deployed in the front-rear direction in order from the central part.

JP-A-11-65628

The above-described “development of actual length applied to the task” is mainly applied to places where the target shape is tightly bent. In addition to this, there are various deployment methods such as “baseline deployment” and “corrected baseline deployment” as the actual length deployment method, and the deployment method is properly used according to the target shape.
The reason for this is that, in real length development, all of distance, angle, and area cannot be developed accurately at the same time, so the curved surface is developed on a plane while maintaining one or two conservation amounts for each shape. .
This situation will be described with reference to FIG. 18. The actual lengths of AB, AC, AD, BC, and BD are accurately obtained at the time of development, whereas CD is an estimated length, and an error is included therein.
For this reason, it is necessary to correct this error at the time of manufacture. Since this correction is different for each shape, the repair work requires skill.
Therefore, since the work method differs depending on the development, selecting an appropriate development method for each shape itself is a work that requires skilled skills. For this reason, there is a problem that the present drawing development worker is required to have experience and intuition, and a worker with less experience cannot obtain a predetermined curved surface. Furthermore, there is a problem that technical tradition is becoming a problem due to a decrease in skilled engineers.

  The present invention has been made in view of such circumstances, and its purpose is to reduce the development error that occurs when the target shape is developed into a member shape, and to realize a parameter actual length that enables highly accurate deployment work. The object is to provide a deployment apparatus, method, and program thereof.

  The present invention has been made to solve the above-described problems. In the present invention, a target shape in real space generated by a predetermined graphic expression is defined by a tangent vector that forms a tangent plane of the target shape. The target shape mapping means for mapping to the parameter space, and the parameter space coordinate value of the mapped target shape as the parameter space coordinate value of the member shape that develops the target shape are used as the parameter space coordinate value of the member shape. Real space coordinate value calculating means for calculating a space coordinate value, and corresponding point distance calculating means for calculating a distance between corresponding points between the target shape and the member shape based on the calculated real space coordinate value of the member shape It is characterized by comprising.

  Further, according to the present invention, the distance calculation means between corresponding points calculates a real space coordinate value corresponding to a parameter space coordinate value between the parameter space coordinate value of the target shape and the parameter space coordinate value of the member shape. The distance between corresponding points between the target shape and the member shape is calculated by cumulatively adding the distance between the calculated real space coordinate value and the calculated real space coordinate value of the member shape. .

  In the present invention, the computer maps a target shape in real space generated by a predetermined graphic representation to a parameter space defined by a tangent vector that forms a tangent plane of the target shape, and the mapped target Using the parameter space coordinate value of the shape as the parameter space coordinate value of the member shape that develops the target shape, a real space coordinate value corresponding to the parameter space coordinate value of the member shape is calculated, and the calculated real space of the member shape A distance between corresponding points between the target shape and the member shape is calculated based on a coordinate value.

  Further, according to the present invention, the distance between corresponding points of the target shape and the member shape corresponds to the parameter space coordinate value between the parameter space coordinate value of the target shape and the parameter space coordinate value of the member shape. A spatial coordinate value is calculated, and the distance between the calculated real space coordinate value and the calculated real space coordinate value of the member shape is cumulatively calculated.

  The present invention also provides a process of mapping a target shape in real space generated by a predetermined graphic expression to a parameter space defined by a tangent vector that forms a tangent plane of the target shape, and the mapped target shape A parameter space coordinate value of the member shape as a parameter space coordinate value of a member shape that develops the target shape, a process of calculating a real space coordinate value corresponding to the parameter space coordinate value of the member shape, and an actual value of the calculated member shape A parameter actual length expansion program for causing a computer to execute a process of calculating a distance between corresponding points between the target shape and the member shape based on a spatial coordinate value.

  Further, according to the present invention, the distance between corresponding points of the target shape and the member shape corresponds to the parameter space coordinate value between the parameter space coordinate value of the target shape and the parameter space coordinate value of the member shape. A spatial coordinate value is calculated, and the distance between the calculated real space coordinate value and the calculated real space coordinate value of the member shape is cumulatively calculated.

As described above, according to the present invention, the target shape in the real space generated by the predetermined graphic representation is mapped to the parameter space defined by the tangent vector that forms the tangent plane of the target shape, and The parameter space coordinate value of the mapped target shape is used as the parameter space coordinate value of the member shape that develops the target shape, and the real space coordinate value corresponding to the parameter space coordinate value of the member shape is calculated, and the calculated member shape The distance between corresponding points between the target shape and the member shape is calculated based on the real space coordinate values.
Therefore, an effect is obtained in which the difference between the actual length of the target shape and the member shape can be estimated as a machining variable. In addition, since this processing variable does not use an approximation method as a development method, it does not include a development error and a highly accurate drawing is output. In other words, because of the geometric solution, the development work can be performed with high accuracy. At the same time, since it is not necessary to select an appropriate deployment method for each shape, the work is skillless, and an effect that even an inexperienced worker can perform the deployment work with high accuracy can be obtained.

  Hereinafter, the best mode for carrying out the present invention will be described.

Hereinafter, an embodiment of a parameter actual length expansion device of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a parameter actual length expansion device according to the present embodiment. The parameter actual length expansion device of this embodiment uses the three-dimensional shape data (target shape curved surface data in FIG. 2 and member shape curved surface data in FIG. 3) obtained from the three-dimensional CAD to uv each of the target shape and the member shape. Convert to parameter space (two-dimensional space in FIG. 4), determine corresponding points between target shape and member shape on uv parameter space, and calculate distance between corresponding points in real space (three-dimensional space) To seek actual length.
That is, as shown in FIG. 1, the parameter actual length expansion device according to the present embodiment inputs target shape curved surface data and member shape curved surface data, and enters a NURBS (Non-Uniform Relational b-spline) expression setting unit 1 and a curvature. The line analysis unit 2 performs pre-processing of actual length calculation processing.

The NURBS expression setting unit 1 sets parameters (control point, knot vector, rank) for expressing the target shape curved surface data and member shape curved surface data in NURBS. In the present embodiment, an example in which NURBS is used as a graphic representation algorithm is shown, but the present invention is not limited to this, and other graphic representation algorithms may be applied.
Similar to the NURBS expression setting unit 1, the curvature line analysis unit 2 performs curvature line analysis on the target shape curved surface data and the member shape curved surface data in the real space coordinate system and the parameter space coordinate system as preprocessing of the input data. Here, the real space coordinate system refers to the so-called three-dimensional (x, y, z) coordinate system shown in FIG. 5, and the parameter space coordinate system as shown in FIG. 6 (and FIG. 4). The uv coordinate system is obtained by mapping the real space coordinate system into a two-dimensional space.
That is, the curvature line analysis unit 2 inputs the target shape curved surface data and the member shape curved surface data in the real space coordinate system, and performs the curvature line analysis for calculating the curvature line and the real space coordinates through which the curvature line passes. In the present embodiment, the curvature line is calculated based on the primary basic quantities E, F, G and the secondary basic quantities L, M, N.

のパラメータ形式で表示される曲面上の点列情報（ｕ、ｖ）のｕとｖに関数関係がある場合、ｓ（ｕ、ｖ）は曲面上の曲線を表し、偏導関数∂ｓ／∂ｕ＝Ｓｕは、ｕ＝一定の曲線の接線ベクトルを表し、偏導関数∂ｓ／∂ｖ＝Ｓｖは、ｖ＝一定の曲線の接線ベクトルを表す。
このとき、基本ベクトルＳｕ、Ｓｖは、曲面の接平面を形成する。また、曲面上の２点ｓ（ｕ、ｖ）からｓ（ｕ＋ｄｕ、ｖ＋ｄｖ）を結ぶベクトルｄｓは

で表される。ここでｄｓの絶対値の二乗は

で表され，曲面の基本ベクトルより、上述の一次基本量が次式で定義される。

また上記式３及び式４をまとめると、

となる。 Hereinafter, a method for calculating the primary basic quantities E, F, G, the secondary basic quantities L, M, N, and the curvature line will be described.

When u and v of the point sequence information (u, v) on the curved surface displayed in the parameter format of s have a functional relationship, s (u, v) represents a curve on the curved surface, and the partial derivative ∂s / ∂ u = Su represents the tangent vector of u = constant curve, and the partial derivative ∂s / ∂v = Sv represents the tangent vector of v = constant curve.
At this time, the basic vectors Su and Sv form a curved tangent plane. A vector ds connecting two points s (u, v) on the curved surface to s (u + du, v + dv) is

It is represented by Where the square of the absolute value of ds is

The above-mentioned primary basic quantity is defined by the following equation from the basic vector of the curved surface.

Moreover, the above formulas 3 and 4 are summarized as follows:

It becomes.

この算出値Ｈを用いて、曲面上の単位法線ベクトルｎは以下の式で表される。

また、曲面上の点Ｐにおける接線ベクトルの線束はこの接平面内に存在し、単位接線ベクトルｔの１つは、以下の式で表される。

このｔとｎで定まる平面を法平面という。また、この法断面上の点Ｐにおける曲率κを法曲率といい、ｔを法断面の弧長ｓで微分すると、

となる。両辺に法線ベクトルを掛けて、以下に示す二次基本量

を導入すると、

となる。
なお、式５を式１２に代入すると、以下の式が得られる。

以上によって一次基本量及び二次基本量から法曲率が算出される。 Assuming that the angle formed by the basic vectors Su and Su is ω, the inner product F and the absolute value H of the vector product of the basic vectors are expressed as follows using a primary basic quantity.

Using this calculated value H, the unit normal vector n on the curved surface is expressed by the following equation.

In addition, a bundle of tangent vectors at a point P on the curved surface exists in this tangent plane, and one of the unit tangent vectors t is expressed by the following equation.

This plane determined by t and n is called a normal plane. Further, the curvature κ at the point P on the normal section is called the normal curvature, and t is differentiated by the arc length s of the normal section,

It becomes. Multiplying the normal vector on both sides, the secondary basic quantity shown below

Introduced

It becomes.
Note that the following formula is obtained by substituting Formula 5 into Formula 12.

Thus, the normal curvature is calculated from the primary basic quantity and the secondary basic quantity.

とおき、さらにκをγの関数κ（γ）と書き直すと、

となる。このγの２次式よりｄκ（γ）／ｄγ＝０において、κ（γ）は極値を取る。 Next, main curvatures κ1 and κ2 in the mesh are calculated based on the primary basic amounts E, F, and G and the secondary basic amounts L, M, and N.
That is, first, the extreme value of the curvature κ is calculated. The shape of the normal section, which is the intersection of the normal plane and the curved surface, changes with the tangential direction, and the normal curvature changes accordingly. This shape returns to the original state after half rotation of the normal plane.
Γ now

And rewriting κ as a function κ (γ) of γ,

It becomes. From the quadratic expression of γ, κ (γ) takes an extreme value when dκ (γ) / dγ = 0.

を得る。そして、式１６に代入すると、

を得る。これらの式より以下の関係式が得られる。

式１８を変形すると、

が得られる。κ〜２の係数は、式７より正であり、この根をκ１、κ２とすると、図６に示すように、この値が主曲率となる。 Then, under this extreme value condition, when Equation 15 is differentiated and κ and γ are rewritten as (κ˜) and (γ˜),

Get. And when substituting into Equation 16,

Get. From these equations, the following relational expressions are obtained.

By transforming Equation 18,

Is obtained. The coefficients of κ˜2 are positive from Equation 7, and when the roots are κ1 and κ2, this value is the main curvature as shown in FIG.

が表現される。ここで、Ｋｍ、Ｋｇはそれぞれ平均曲率及びガウス曲率である。Ｋｇ＝０となるのは、曲面が可展面となる場合であり、曲面上の曲率線は直線になる。 Next, a Gaussian curvature or an average curvature is calculated based on the main curvature. That is, from the relationship between the root of the quadratic equation and the coefficient,

Is expressed. Here, Km and Kg are an average curvature and a Gaussian curvature, respectively. Kg = 0 is when the curved surface becomes a developable surface, and the curvature line on the curved surface becomes a straight line.

または、

を得る。これら２式はともに、曲率線の式であり、２次方程式であるので、γ１、γ２は以下の関係がある。

曲面上の点において、γ１、γ２で決まる方向において、曲率は極値を取る。曲面上の接線ベクトルは、（Ｓｕｄｕ＋Ｓｖｄｖ）であり、γ１、γ２に対応する２つの接線ベクトルの内積は、

となり、この{ }内を変換すると、

はゼロとなる。すなわち、主曲率の法断面の２つの接線方向は、直交している事が分かる。この方向は主方向と呼ばれ、この主方向と曲面上の接線が一致する場合、これが曲率線となる。
以上により、メッシュの主方向を示す曲率線の算出処理が行われる。 Also, a curvature line indicating the main direction of the mesh is calculated based on the main curvature. That is, if κ˜ is eliminated from Equation 29,

Or

Get. Both of these two equations are equations of curvature and are quadratic equations, so that γ1 and γ2 have the following relationship.

At a point on the curved surface, the curvature takes an extreme value in a direction determined by γ1 and γ2. The tangent vector on the curved surface is (Sudu + Svdv), and the inner product of the two tangent vectors corresponding to γ1 and γ2 is

And if you convert within this {},

Becomes zero. That is, it can be seen that the two tangent directions of the normal curvature normal section are orthogonal. This direction is called the main direction, and when this main direction and the tangent on the curved surface coincide, this becomes a curvature line.
Thus, the calculation process of the curvature line indicating the main direction of the mesh is performed.

About the curvature line in the target shape and member shape calculated as described above, the curvature line analysis unit 2 further calculates real space coordinates through which the curvature line passes at an appropriate division interval.
Then, the curvature line analysis unit 2 maps the calculated curvature line and the real space coordinate value passing therethrough to the parameter space. Thereby, the target shape in the real space generated by the predetermined graphic expression is mapped to the parameter space defined by the tangent vector that forms the tangent plane of the target shape.

The parameter space coordinate value calculation unit 3 is based on the curvature line passage information (curvature line in the real space coordinates / parameter space coordinates, the coordinate value through which the curvature line passes) input from the curvature line analysis unit 2. The coordinates of the intersection between the plurality of curvature lines are calculated. Specifically, as shown in FIG. 4, intersection coordinate values (u, v) of a plurality of curvature lines extending in the u-axis direction and the v-axis direction are obtained.
The real space coordinate value calculation unit 4 reverse-maps the intersection point between the plurality of curvature lines in the parameter space input from the parameter space coordinate value calculation unit 3 to the real space for each of the target shape and the member shape. Calculate real space coordinate values. Alternatively, the real space coordinate value calculation unit 4 uses the parameter space coordinate value (which may coincide with the intersection) of the mapped target shape as the parameter space coordinate value of the member shape, and corresponds to the parameter space coordinate value of the member shape. Calculate real space coordinate values.
The curvature line passage order arranging unit 5 rearranges the real space coordinates and the intersection coordinates through which the curvature lines input from the real space coordinate value calculation unit 4 pass in the order in which the curvature lines pass for each of the target shape and the member shape.

The actual length calculation unit 6 identifies the corresponding intersection for each of the target shape and the member shape based on the order in which the curvature line passage order alignment unit 5 has rearranged. Then, the distance between the corresponding intersections is calculated, and by obtaining this difference, the distance between the corresponding points between the target shape and the member shape, that is, the machining variable is calculated. Alternatively, the actual length calculation unit 6 calculates the distance between corresponding points between the target shape and the member shape in the real space based on the real space coordinate value corresponding to the parameter space coordinate value of the member shape. In any of the calculation methods of the distance between corresponding points with the shape, the real length corresponding to the parameter space coordinate value between the parameter space coordinate value of the target shape and the parameter space coordinate value of the member shape in the actual length calculation unit 6 A coordinate value is calculated, and the distance between the calculated real space coordinate value and the real space coordinate value of the member shape calculated by the real space coordinate value calculation unit 4 is cumulatively added.

The base line setting unit 7 performs a Gaussian curvature distribution analysis as shown in FIG. 7, and determines a base line based on the result of the curvature line analysis (see FIG. 8).
The real length expansion unit 8 performs a real length expansion by multiplying the center of the base line determined by the base line setting unit 7 by using the distance between the intersections calculated by the real length calculation unit 6 and developing the real space coordinates. Is calculated.

Next, the operation of the parameter actual length expansion device of this embodiment will be described with reference to the drawings. FIG. 9 is a flowchart showing the process of parameter actual length expansion processing in the parameter actual length expansion device of this embodiment.
Now, when the target shape curved surface data and the member shape curved surface data are input to the parameter actual length developing device, the NURBS representation setting unit 1 sets the above-described curved surface representation parameters (control point, knot vector, rank) (FIG. 9). In step S1), the curvature line analysis unit 2 calculates curvature line passage information (real space coordinates / parameter space coordinates) (step S2).
The parameter space coordinate value calculation unit 3 is based on the curved surface data and the curvature line passage information in the NURBS expression input from the NURBS expression setting unit 1 and the curvature line analysis unit 2, and the coordinates of the intersections between the plurality of curvature lines in the parameter space. Is calculated (step S4).

FIG. 10 shows a detailed processing flow of step S4.
That is, the parameter space coordinate value calculation unit 3 calculates the distance between the plurality of curvature lines (curvature lines) in the parameter space shown in FIG. 4 based on the curvature line passage information input from the curvature line analysis unit 2 for each of the target shape and the member shape. The intersection of the parameter space line segment and the parameter space line segment of another curvature line is calculated (step S10). Then, the lattice point parameter coordinates of the curvature line mesh are substituted to obtain intersection information of the curvature line (step S11).
Thus, the intersection parameters and intersecting line information are calculated.

Next, the real space coordinate value calculation unit 4 sets the intersection point obtained in step 10 as a reverse mapping target point, and sets a line passing through the reverse mapping target point in the parameter space. The line passing through the inverse mapping target point may be either a straight line or a curved line, but is a line expressed by a known function parameter. In the present embodiment, for simplicity, a case where u = a constant straight line will be described.
That is, the real space coordinate value calculation unit 4 calculates the real space coordinates of the intersection point on the parameter space between the u = constant straight line passing through the inverse mapping target point and the curvature line mapped on the parameter space. (Step S4). More specifically, the real space coordinate value calculation unit 4 calculates the real space coordinates through which the curvature line in the real space passes and the start point of the curvature line in the parameter space (the intersection of v = 0 and the curvature line) to the intersection. The ratio of the actual long distance along the curvature line and the total length of the curvature line,
(Distance from the start point to the intersection point) / (Total length of curvature line)
The real space coordinates of the intersection are calculated based on the parameters indicated by.

The curvature line passing order aligning unit 5 rearranges the real space coordinates and the intersection coordinates through which the curvature lines input from the real space coordinate value calculating unit 4 pass in the order in which the curvature lines pass for each of the target shape and member shape ( In step S5), the actual length calculation unit 6 identifies the corresponding intersection point for each of the target shape and the member shape based on the order rearranged by the curvature line passage order alignment unit 5. Then, the distance (actual length) between the corresponding intersections is calculated based on the passing point information.
FIG. 11 shows a detailed calculation flow of the distance between the corresponding intersections.
First, the actual length calculation unit 6 determines a designated parameter range in the parameter space based on the two specified intersections for each of the target shape and the member shape, and specifies them by the same method as the real space coordinate value calculation unit 4 A real space coordinate value corresponding to the parameter space coordinate value of the two intersected points is obtained (step S20). In the first loop, since there is no previous coordinate value in real space, step S21 is skipped. Then, one specified parameter is advanced toward the other specified parameter by a small step size of a predetermined parameter space with respect to the distance between the two specified intersections. That is, only a small step size is set to the specified parameter. Add (step S22).

Here, if the addition result exceeds the specified parameter range (No in step S23), the distance (actual length) between the two specified intersections is output, and if not exceeded (Yes in step S23), further Steps S20 to S22 are repeatedly executed.
That is, in a state where one of the designated parameters is added, the corresponding real space coordinate value is calculated again (step S20), and the linear distance from the previous (first) calculated real space coordinate value is calculated. These are cumulatively added (step S21). As described above, add the specified parameter by a small step within the range that does not exceed the specified parameter range, add the linear distance to the calculated coordinate value in the real space, and repeat this Thus, the actual length is calculated when the specified parameter range is exceeded, that is, when the other specified parameter is exceeded.
As described above, the actual length between the intersections of the curvature lines is calculated.

FIG. 12 and FIG. 13 are flowcharts showing a process of task length actual length expansion.
As described above, when a mesh with a curvature line is created in the parameter space and the actual length of the mesh lattice side is calculated (step S30 in FIG. 12), the baseline setting unit 7 performs a Gaussian curvature distribution analysis, and the curvature line analysis is performed. A baseline line is determined based on the result (step S31).
The real length expansion unit 8 performs a real length expansion by multiplying the center of the base line determined by the base line setting unit 7 by using the distance between the intersections calculated by the real length calculation unit 6 and developing the real space coordinates. Is calculated. That is, the actual length expansion unit 8 reads the control points and knot vectors of the surface (step S40 in FIG. 13), and divides the elements in the longitudinal direction as shown in FIG. 15, centering on the base line X as shown in FIG. Then, the lengths of the four sides and the diagonal line are calculated for each divided element (step S42).
Then, when the development of the central mesh is completed in the plate width direction from the base line X, the development further proceeds from the center toward both ends.

As shown in FIG. 16, for each mesh development method, the point B point C is first fixed, and the intersection point A is obtained from the diagonal line AC and the side AB (step S43). Next, the point B is fixed, the intersection D is obtained from the diagonal line DB and the side CD (step S44), and the length between the obtained points A and D and the length between the points A and D obtained from the parameters are determined. A new point A point D having an average length is compared (step S45).
As the reference point B point C, the upper two points of the lower element that have already been obtained are substituted.
Here, the line length AD obtained by the multiplication is different from the line length AD obtained by the uv parameter. Therefore, as shown in FIG. 17, in order to reduce the error, each coordinate value is corrected to an average (L−L ′) / 2. Here, L represents the actual length on the curved surface, and L ′ represents the distance between the two points obtained by task multiplication.
The above calculation process is first repeatedly executed for the number of elements in the plate width direction (Yes in step S46), and then the number of elements in the plate longitudinal direction is repeatedly executed to complete the unfolding process (Yes in step S47).

  As described above, according to the parameter actual length developing device of the present embodiment, the effect that the difference between the target shape and the actual length of the member shape can be estimated as the machining variable is obtained. In addition, since this processing variable does not use an approximation method as a development method, it does not include a development error and a highly accurate drawing is output. In other words, because of the geometric solution, the development work can be performed with high accuracy. At the same time, since it is not necessary to select an appropriate deployment method for each shape, the work is skillless, and an effect that even an inexperienced worker can perform the deployment work with high accuracy can be obtained.

In the present embodiment, for each of the target shape and the member shape, the actual length between the intersections of the curvature lines is calculated, and the distance between corresponding points between the target shape and the member shape is obtained by obtaining this difference. In other words, the example in the case of calculating the machining variable is shown, but the present invention is not limited to this, and the u and v coordinate values of the target shape are projected onto the member shape (parameter space) and directly on the real space. The distance between corresponding points of the target shape and member shape may be calculated. In this case, the curvature line analysis unit 2 makes the target shape non-dimensional and projects it on the uv space (uv conversion), and the parameter space coordinate value calculation unit 3 calculates the mesh coordinate position (u, v coordinate value) of the target shape. Ask for.
Then, the parameter space coordinate value calculation unit 3 sets the (target shape) u and v coordinate values of the parameter space as u and v coordinate values of the member shape, that is, the u and v coordinate values of the target shape are set as the member shape (parameter The real space coordinate value calculation unit 4 converts the u and v coordinate values of the member shape into real space coordinate values (x, y, z). The real space coordinate value calculation unit 4 similarly calculates the real space coordinate value by the curvature line passage order alignment unit 5 to rearrange the target shape and the member shape in the order in which the curvature line passes, and the real length calculation unit. 6, the distance between corresponding points of the target shape and member shape is calculated.
By comprising in this way, the effect that the difference of the actual length of a target shape and a member shape can be estimated as a processing variable is acquired. In addition, since this processing variable does not use an approximation method as a development method, it does not include a development error and a highly accurate drawing is output. In other words, because of the geometric solution, the development work can be performed with high accuracy. At the same time, since it is not necessary to select an appropriate deployment method for each shape, the work is skillless, and an effect that even an inexperienced worker can perform the deployment work with high accuracy can be obtained.

The above-described parameter actual length expansion device has a computer system therein.
A series of processes related to the parameter actual length expansion process described above is stored in a computer-readable recording medium in the form of a program, and the above process is performed by the computer reading and executing this program. .
That is, each processing means and processing unit in the parameter actual length expansion device is such that a central processing unit such as a CPU reads the above program into a main storage device such as a ROM or RAM, and executes information processing / calculation processing. Is realized.
Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

The block diagram of a parameter actual length expansion | deployment apparatus. Target shape diagram. FIG. Explanatory drawing of uv coordinate system which shows parameter space. Explanatory drawing of the xyz coordinate system which shows real space. FIG. 6 is an explanatory diagram of a uv coordinate system showing a parameter space mapped from FIG. 5. The Gaussian curvature distribution map of a target shape. Explanatory drawing which shows the curvature curve analysis result of a target shape. The flowchart which shows the process of parameter actual length expansion | deployment processing. The flowchart which shows the detailed process flow of step S4. The flowchart which shows the detailed calculation flow of the distance between corresponding intersections. The flowchart which shows the process of a tacking actual length expansion | deployment. The flowchart which shows the process of a tacking actual length expansion | deployment. The figure which shows how to take the base line X. FIG. The figure which shows the mode of element division. The development view of each mesh. A modified development view of each mesh. The characteristic explanatory view of real length deployment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... NURBS expression setting part 2 ... Curvature line analysis part 3 ... Parameter space coordinate value calculation part 4 ... Real space coordinate value calculation part 5 ... Curvature line passage order alignment part 6 ... Real length calculation part 7 ... Baseline line setting part 8 ... Actual length development department

Claims (6)

A target shape mapping means for mapping a target shape in real space generated by a predetermined graphic representation to a parameter space defined by a tangent vector forming a tangent plane of the target shape;
Using the mapped parameter space coordinate value of the target shape as the parameter space coordinate value of the member shape that develops the target shape, calculating the real space coordinate value corresponding to the parameter space coordinate value of the member shape Means,
Corresponding point distance calculation means for calculating a distance between corresponding points between the target shape and the member shape based on the calculated real space coordinate value of the member shape. . The corresponding point-to-point distance calculation means
Calculating a real space coordinate value corresponding to a parameter space coordinate value between the parameter space coordinate value of the target shape and the parameter space coordinate value of the member shape;
The distance between corresponding points between the target shape and the member shape is calculated by cumulatively adding the distance between the calculated real space coordinate value and the calculated real space coordinate value of the member shape. Item 3. The parameter actual length expansion device according to Item 1. Computer
A target shape in real space generated by a predetermined graphic representation is mapped to a parameter space defined by a tangent vector forming a tangent plane of the target shape;
The parameter space coordinate value of the mapped target shape is used as the parameter space coordinate value of the member shape that develops the target shape, and the real space coordinate value corresponding to the parameter space coordinate value of the member shape is calculated,
Based on the calculated real space coordinate value of the member shape, a distance between corresponding points between the target shape and the member shape is calculated. The distance between corresponding points of the target shape and the member shape is
Calculating a real space coordinate value corresponding to a parameter space coordinate value between the parameter space coordinate value of the target shape and the parameter space coordinate value of the member shape;
The parameter actual length expansion method according to claim 3, wherein a distance between the calculated real space coordinate value and the calculated real space coordinate value of the member shape is cumulatively added. A process of mapping a target shape in real space generated by a predetermined graphic representation to a parameter space defined by a tangent vector forming a tangent plane of the target shape;
Processing the parameter space coordinate value of the mapped target shape as the parameter space coordinate value of the member shape that develops the target shape, and calculating the real space coordinate value corresponding to the parameter space coordinate value of the member shape;
A parameter actual length expansion program for causing a computer to execute a process of calculating a distance between corresponding points between the target shape and the member shape based on the calculated real space coordinate value of the member shape. The distance between corresponding points of the target shape and the member shape is
Calculating a real space coordinate value corresponding to a parameter space coordinate value between the parameter space coordinate value of the target shape and the parameter space coordinate value of the member shape;
6. The parameter actual length expansion program according to claim 5, wherein the parameter actual length expansion program is calculated by cumulatively adding the distance between the calculated real space coordinate value and the calculated real space coordinate value of the member shape.

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