JP2010169395A - System and method for evaluating degree of completion of processing of curve-shaped member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for evaluating the degree of completion of processing of a curve-shaped member which evaluates and determines the shape of a curved surface of the curve-shaped member after processing, confirming the processing accuracy of the curved surface of the curve-shaped member that is under processing or which has been processed during the course of forming the curved surface. <P>SOLUTION: The method for evaluating the degree of completion of processing of a curve-shaped member includes a step of measuring the shape of a curved surface that is under processing, or has been processed by a measuring apparatus; a step of forming a surface and point by inputting data of the measured shape of the curved surface and data of a designed shape of the curved surface; a step of matching curved surfaces which matches the measured shape of the curved surface with the shape of the curved surface which has been designed in reflection of a margin portion, in a manufacturing process of a ship's hull and specific constraint conditions of a chamfering operation; a step of calculating an error amount between the curved surfaces; and a step of evaluating the degree of completion of processing of the shape of the curved surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a curved member processing completeness evaluation system and a method thereof, and more particularly, measurement using a measurement system and data thereof are being processed or processing completeness of a processed curved member. The present invention relates to a system and method for evaluating the degree of completeness of a curved member capable of evaluating and judging the above.

  In general, the three-dimensional curved shape not only makes the appearance of the product beautiful, but also plays a major role in actually reducing the resistance of the fluid. For these reasons, many industrial products such as automobiles, aviation, shipbuilding, etc. have various curved shapes. In particular, the curved surface shape used for ship construction is concentrated mainly on the bow and stern portions of the hull, and the performance deviation of the ship is caused by these curved surface shapes.

  As described above, most of the three-dimensional curved surface-shaped members used at the time of building a ship are made of a steel material, and the size, weight, and shape are various although they are large compared to other industries. Such a difference requires a method different from a method of forming a curved surface through a mechanical forming method such as a die press, a non-die press, and a rolling mainly used in other industries. An example of a suitable processing method is a molding method by thermal processing. The thermal processing method is a method for producing a desired curved surface shape by inducing residual thermal elastic-plastic deformation, which is represented by bending deformation and contraction deformation, by applying heat to the surface of an iron plate with a gas torch or the like. In recent years, active efforts have been made to apply molding methods such as mechanical press molding, roll molding, and multi-point press molding to 3D curved outer plate molding for ships in order to replace thermoforming methods with poor working environments. However, the results are still poor.

  As described above, most of the three-dimensional curved surface shape for ships is manufactured by a heat processing molding method, and in order to take a form in which the member is processed to match the design shape using heat, The shape is checked at any time, and the machining process is performed multiple times until the given accuracy is met. A method of checking the accuracy of the curved surface shape using a wooden mold that represents the three-dimensional design shape in order to check the similarity and accuracy with the design shape in such a confirmation process and to determine the direction of subsequent thermal processing However, in this method, the error confirmation and evaluation between the wooden mold and the workpiece are totally dependent on the operator's vision and judgment.

  On the other hand, even a three-dimensional curved surface shape that has undergone thermal processing is different from the design shape in size, and most of the shape is larger than the design shape. The reason why such a phenomenon occurs is as follows.

  Due to the characteristics of thermal processing, plastic deformation such as bending and contraction occurs due to expansion during heating and contraction during cooling. However, due to the complexity of the three-dimensional curved surface shape and the processing uncertainty during thermal processing, the designer is The margin value of margin M as shown in FIG. 6 is given to the initial shape in which the three-dimensional design shape is developed on a flat plate. 1 is a display of the designer that allows the designer to measure / cut the worker with respect to the outline. In addition, as shown in FIG. 2, it is defined that a chamfering operation C (beveling) is performed on the outer shell of the steel material for a welding operation in a later process, but this operation is a general cutting operation. The harder it is to compare, the more difficult work is required.

  In order to reflect such process characteristics and difficulties, the chamfering work is first performed in the initial flat plate shape so that the work can be relatively easily performed on some outlines, and the remaining parts The cutting and chamfering of the margin is performed in the state of the three-dimensional curved surface member in which the thermal processing is completed only. This is considered to be a process provided to perform a minimum cutting operation in the margin cutting process for productivity.

  However, due to the uncertainties of the thermal processing described above, the comparison of the completed curved surface, and the backwardness of the evaluation method, the margin is cut so that the previously chamfered portion cannot be used, and the chamfering operation is performed again at a considerable rate. In some cases.

  In order to overcome this, in recent years, a method has been proposed in which the shape coordinates of a workpiece are measured using a three-dimensional measuring instrument and the like, and the machining accuracy is managed through numerical comparison with the corresponding coordinates in the design shape.

  Such a method uses a surface matching technique that optimally matches the coordinates between the design coordinates (or curved surface) and the measurement coordinates (or curved surface), and then the distance error between the two coordinates (or curved surface) and Z A method of providing an error in the Z-axis direction called a map.

  However, such a method cannot reflect peculiarities such as a difference in size due to a margin and a chamfering operation in the above-described curved surface member of the hull. In addition, due to the limitation that the measurement coordinates must be measured so that a certain correspondence with the design coordinates is established, its use is limited only to the evaluation of the final curved surface shape after completion of machining, and the result is also between data. It provides restrictive information such as the absolute value of the distance error and the distance error in the Z-axis direction. However, in the end, problems such as evaluation of the degree of processing completion of the curved surface shape measured by the above method and calculation of the amount of cutting depend on the experience and intuition of the operator.

  Apart from this, various research institutes have recently developed automated processing systems for curved surfaces of the hull, but it seems to develop automated systems using thermal processing methods or automated systems using other machining methods. Even in this case, it becomes difficult to evaluate the three-dimensional curved surface shape using the current tree pattern. Despite the need for measurement using a measurement system, and a curved surface shape evaluation method and system using the data, most of the work that has been studied so far is the machining position for curved surface forming. In addition, there is no research on a method and a system for evaluating and judging the degree of completeness of the curved shape of a curved member that is being processed or is only content related to strength and the like.

  In addition, a system has been proposed that automates only the machining operation based on the operator's instructions on whether to repeatedly process, molding position, molding strength, etc. Such partial automation equipment is fully automated. There is a problem that the cost and efficiency are lower than those of the system.

  Therefore, the present invention has been made in view of the above circumstances, and its purpose is to confirm the processing accuracy of the curved surface in the process of forming the curved surface of the curved member that has been processed, and to determine the shape after processing. It is an object of the present invention to provide a processing member evaluation system and method for a curved member that can be evaluated and judged.

  Another object of the present invention is to provide a curved member processing completeness evaluation system and method that can be combined with a marine curved surface forming automation system capable of automatically performing curved surface forming and provide the end point of the processing automation operation. It is in.

  Another object of the present invention is to provide a curved member processing completeness evaluation system and method which can be widely used not only for the production of curved hull surfaces but also for the evaluation and production of products having curved surfaces. is there.

  In order to achieve the above object, the present invention includes a step of measuring a curved surface shape being processed or processed by a measuring device, and inputting the measured curved surface shape data and the designed curved surface shape data to obtain the surface and the point. A curve matching stage that matches the measured curved surface shape with the curved surface shape that reflects the marginal part of the hull manufacturing process and the specific constraints of the chamfering operation, and the amount of error between the curved surfaces Provided is a curved surface shape evaluation method for a curved member, comprising a step of calculating and a step of evaluating a processing completeness of a curved surface shape.

  In addition, the curved member processing completeness evaluation system includes an input module in which measurement data and design information measured with respect to the curved surface shape of the curved member, and a surface and points of the measurement curved surface and the design curved surface. The surface and point generation module that generates the position of the coordinates relative to the surface, the optimum surface matching module that performs surface matching with curved surface matching and constraint conditions, and the degree of similarity between the design surface and the measurement surface based on the result of the surface matching as a percentage value Processing perfection evaluation of a curved member comprising a processing perfection module to be presented and a cutting position and error calculation module for calculating a cutting position and an error when the numerical value presented from the processing perfection module is a curved surface completion condition Provide a system.

  As described above, according to the processing completeness evaluation system and method of a curved member according to the present invention, whether the processing is in progress, or confirming the processing accuracy of the curved surface in the curved surface forming process of the completed curved member, Since the shape after processing can be evaluated and judged, it can be combined with an automated system for curved surface forming for ships that can automatically perform curved surface forming, and the end point of processing automation work can be provided. In addition, there is an effect that it can be widely used for the evaluation and production of the shape of a curved surface molded product having a curved surface specificity.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 3 is a diagram showing a configuration and information flow of a curved member processing completeness evaluation system according to a preferred embodiment of the present invention.

  As shown in FIG. 3, the curved member processing completeness evaluation system of the present invention includes an input module 10 into which measurement data and design information measured with respect to a curved surface shape of a curved member, and a curved surface. And a surface and point generation module 20 that generates a coordinate position with respect to a point, an optimum curved surface matching module 30 that performs curved surface matching and curved surface matching with constraints, and a similarity between a design curved surface and a measured curved surface based on the result of curved surface matching And a cutting position and error calculation module 50 for calculating a cutting position and an error when the numerical value presented by the processing completion module 40 is a curved surface completion condition.

  The optimum curved surface matching module 30 separately provides the result of the optimum curved surface matching to the machining information generation system 60 in order to be used for generating machining information. When the presented numerical value is not a curved surface completion condition, the processing completeness module 40 transmits a command for generating additional processing information to the processing information generation system 60.

  When the cutting position and the error amount are calculated in accordance with the curved surface completion conditions, the corresponding information is transmitted to the cutting position display and cutting system 70 to perform the cutting operation.

  All information of the evaluation system of the present invention is automatically stored in the storage device 80 and transmitted to the video display device 100 such as an LCD and the printer 110 via the output module 90, and the user can visually confirm the progress. It is configured as follows.

  FIG. 4 is a flowchart for explaining the process of evaluating the degree of machining completion of the system for evaluating the degree of machining completion of the curved member of the system of the present invention.

  As shown in FIG. 4, the process completion degree evaluation process is measured by a step S100 of measuring a state in a curved surface machining process or a processed curved surface shape by a measuring device (not shown) such as a three-dimensional measuring instrument. Reflecting the curved surface shape data and the designed curved surface shape data to the input device 10 to generate the surface and points, the margin part of the hull manufacturing process and the specific constraints of the chamfering operation, A curved surface matching step S300 for matching the designed curved surface shape and the measured curved surface shape by the optimum curved surface matching module 30, a step S400 for calculating an error amount between the curved surfaces, and a step S500 for evaluating the degree of processing completion of the curved surface shape. Including.

  Then, the cutting position and error calculation module 50 transmits the cutting position information based on the error amount and the evaluation result to the cutting position display and cutting system 70 (S600).

  Since the measurement in the measurement step S100 is generally performed using three-dimensional point information, if a three-dimensional curved surface is generated based on the three-dimensional point information, at this time, the design curved surface shape data and the measurement shape It is divided into evaluation of the hull curved surface shape when the data is in a correspondence relationship and when the data is not.

  When determining and measuring a position that matches the design data with a one-to-one correspondence, first, data corresponding to a specific interval or position to be measured is obtained from the design shape. Based on the obtained data, a portion that is determined to be the corresponding coordinate in the curved surface shape to be measured is measured. At this time, the design shape coordinates in the corner portion to which the margin is given are present on the actually measured curved surface in consideration of the cutting of the margin margin. A one-to-one correspondence with the shape data can be set. In such a method, since the position of the internal structure is attached to the curved member of the hull, the position can be displayed in advance or extracted from the design coordinates so that the approximate position can be estimated. By using such information, it becomes possible in practice.

  On the other hand, if there is no correspondence between the design curved surface shape and the measured curved surface shape, whether to measure unspecified internal position and corner coordinates as measurement coordinates, or to measure the internal position and corner coordinates with a certain rule Measure by the method of scanning the surface of the curved surface precisely.

  As described above, the measurement curved surface shape information measured using an appropriate measuring device is matched with the corresponding coordinates of the design curved surface shape to calculate an error amount and the like (S300 and S400).

  In calculating the amount of error, not only the simple distance between the measurement coordinates and the design coordinates but also the directionality for cutting the margin must be presented with respect to the contour of the curved surface. It can be confirmed through FIG. 5A showing the position and FIG. 5B showing the position after the curved surface matching of the measurement coordinates. The points in FIG. 5A are points extracted on the design curved surface, and the points in FIG. 5B are points measured on the measurement curved surface. As can be confirmed from FIGS. 5A and 5B, there are five coordinates with large errors. By moving the coordinates having such a large error in the direction of the arrow in FIG. 5B, a shape that relatively matches the design shape can be obtained.

であり、
ｃベクトルは、ｃ＝ｂ−ａのベクトル計算により求めることができる。 Thus, in the present invention, not only the distance error between the measurement coordinates and the design coordinates but also the directionality can be presented by using the direction presentation method utilizing the inner product of vectors as shown in FIG. As shown in FIG. 6, when a triangular shape is formed using a point A of the design shape, a point B of the measurement shape corresponding thereto, and a point C existing inside the design shape or the measurement shape, each side is represented by a, If expressed as vectors b and c, the angle θ between the vectors b and c is

And
The c vector can be obtained by vector calculation of c = b−a.

  As described above, in the case of FIG. 6, when θ> 90 ° according to the magnitude of the calculated angle θ, it is possible to provide information that the measurement coordinates are located outside the design coordinates, and θ <90. In the case of °, information that the measurement coordinate is located inside the design coordinate can be provided. Of course, the standard of 90 ° must be slightly changed according to the angle formed by the vectors a and b, but it is ignored because the value is considered to be very small even with a similar curved surface shape.

  On the other hand, as a technique for matching two shapes having different reference coordinate systems, a method using a pseudo-transformation matrix and a nearest point search algorithm, or a method for finding an optimum match when an exact correspondence between two shapes is given (Horn's Method) [Horn, BK P, 1987, "Closde-form solution of absolute orientation using unit quaternions", Journal of Optical Society of America, Vol. 4, pp. 629-624.] ICP (Interactive Closest Point) method with excellent convergence using the least square function based on distance [Besl, PJ, McKay, ND, 1992, "A Method for Registration of 3-D Shapes", IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 14, No. 2, pp. 239-256.] And other forms of curved surface matching technology are disclosed, but the 3D hull curved surface shape evaluation process is fully utilized. There are no systems, methods, etc. In particular, in the past, no consideration has been given to adding singular points such as margin parts in the manufacturing process of the hull curved surface and chamfering (improvement) work as constraints in the curved surface matching theory.

  In other words, the existing curved surface matching methods have different coordinate systems and are intended only to perform optimal coordinate matching and shape matching between two shapes having different shapes. In the present invention, as in the hull curved surface machining process, the theory was developed so that coordinates and curved surfaces can be matched by reflecting specific constraints at the time of curved surface matching, and the used constraints are measured shape and design shape. The chamfered (improved) processed part is matched to the maximum.

  For this reason, in the case where it is known that there is a correspondence between the specific coordinates of the design shape and the coordinates of the measurement shape, the following constraints are taken into consideration, although the horn method is used.

  The basic method of the horn is to determine the optimal rigid body deformation that minimizes the objective function when the least square error after matching is determined for the two shapes in the objective function. After applying, alignment is performed through the process of translation based on the centroid.

  On the other hand, in the present invention, as shown in FIG. 7, in order to reflect the constraint condition for optimally matching a part of the corner of the curved surface shape, by adding or superimposing the same point as the corner point to be constrained, it is used as a reference for translation. The centroid is moved to the corner that is the constraint. Superimposition by adding a point realizes an effect of weighting the corresponding point, and the position of the centroid moves in the corner direction of the constraint condition. Thereafter, the optimum rotation is performed again to complete the curved surface matching considering the constraint conditions. The result thus obtained shows a difference in the position of the centroid and the error value between the design and measurement points in the existing method, and the matching result and the error value optimally matched with the presented corner are extracted. To do.

  On the other hand, if the exact correspondence is not known, the least square function based on the distance is used so that the optimum surface matching and error calculation can be performed in consideration of the constraints in the general ICP method described above. It was.

  That is, as in the case of the above-described horn method that has been used, when the error after matching is used as an objective function for two shapes, this objective function is defined as shown in Equation 1.

ここで、Ｐ_ｉ、Ｒ（ｑ_ｉ）、Ｔはそれぞれ大きさ調整因子、回転因子、並進因子である。
このような目的関数への制約を考慮すれば、制約されるコーナーの頂点の１つを制約基準点として定める場合、並進因子は容易に求められるので、前記目的関数は式２のように定義される。 (Formula 1)

Here, P _i , R (q _i ), and T are a size adjustment factor, a twiddle factor, and a translation factor, respectively.
In consideration of such constraints on the objective function, the translation factor can be easily obtained when one of the corner vertices to be constrained is defined as the constraint reference point. Therefore, the objective function is defined as shown in Equation 2. The

式中において、ａ部分の値が最大となるとき、目的関数は一部のコーナーを最適整合する制約条件を忠実に反映するようになる。 (Formula 2)

In the equation, when the value of the a part becomes maximum, the objective function faithfully reflects the constraint condition that optimally matches some corners.

  Subsequent processes are performed in the same way as the normal ICP method, and the objective function of the present invention in which the constraint condition is considered as described above can be easily applied to the Horn method that reflects the constraint condition.

  On the other hand, when one of the corner vertices to which the constraint condition is given is defined as the “constraint reference point”, the translation factor can be easily obtained, but the “constraint reference point” has a phenomenon that the degree of freedom becomes zero. appear. In some cases, such a phenomenon can be used, but with curved surface matching that takes into account machining errors, etc., a variety of curved surface matching results can be obtained by allowing movement within an allowable error range even at the “constraint reference point”. There is a need to ensure sex.

  FIG. 8 shows a form after curved surface matching that reflects the coordinate position and constraint conditions before curved surface matching using the system of the present invention. As shown in the figure, in the present invention, the “constraint reference point” can be freely moved within the area of the three-dimensional allowable error spherical surface to ensure the diversity of the overall curved surface shape matching result and to obtain the final completed curved surface member. The subsequent post-processing work can be minimized.

  FIG. 9 shows an actual configuration when the degree of freedom of the “constraint reference point” is 0, and FIG. 10 shows that the “constraint reference point” can be moved within the allowable error range using the spherical error region. The state in which the optimum curved surface is matched in the state is shown.

  As described above, when matching between shapes is performed through the curved surface matching method, a standard and method for calculating and judging the similarity between curved surfaces and a system for realizing the same are necessary. In the case of a curved surface of the hull, a method using a tree shape by an operator is used as a criterion for calculating and judging this, but in the present invention, the geometric distance (or principal curvature) between curved surfaces and its direction are analyzed, and curved surfaces are divided. The degree of similarity between curved surface shapes can be judged based on various criteria such as the size of the area and the method through curvature.

  First, the method using the geometric distance can determine the degree of completeness of the shape by comparing the distance data obtained for each corresponding point and the allowable error by configuring the points that correspond with the measured shape and the design shape. The geometric distance between corresponding points is expressed by Equation 3 below.

ここで、Ｐ_ｉとＱ_ｉは、それぞれ形状間の最小距離を有する設計形状と目的形状の対応点である。 (Formula 3)

Here, P _i and Q _i are corresponding points of the design shape and the target shape having the minimum distance between the shapes, respectively.

The degree of similarity of curved surfaces can be evaluated within a specific tolerance δ using the above equation 3. For example, if ε _i > δ in a specific corresponding point relationship, the similarity between two shapes at a corresponding point is It means to decline. If such a process is performed for each of the corresponding points for which the correspondence relationship is established on the two curved surfaces, the processing completeness of the curved surface member can be expressed in percent (%) using Equation 4. .

ここで、Ｄ_ｒは完成度評価を行う２つの形状間の対応点の個数であり、Ｄεは類似度が低下するε_ｉ＞δである時になす対応点の個数である。 (Formula 4)

Here, D _r is the number of corresponding points between the two shapes which performs complete evaluation, D [epsilon] is the number of corresponding points that form when in epsilon _i> [delta] similarity decreases.

  Unlike this, the curved surface shape is divided into specific reference elements, the similarity of the divided elements is analyzed, and the curved surface member is processed with the ratio of the elements with high or low similarity to the total number of divided elements Completion degree can be calculated, and various criteria such as comparison of geometric distance and curvature between feature points of division elements, and comparison of area are applied to evaluate similarity between division elements at this time. obtain. After evaluating the degree of similarity in this way, the percentage (%) of the degree of completion of the curved surface is expressed as Equation 5.

ここで、Ｅ_ｒは完成度評価を行う２つの形状間の分割要素の個数であり、Ｅ_εは類似度が低下するε_ｉ＞δである時になす分割要素の個数であり、曲面を分割する要素の個数は提供される設計形状の大きさ及び曲率情報に応じてその値が能動的に変わる。 (Formula 5)

Here, E _r is the number of division elements between two shapes to be evaluated for completeness, and E _ε is the number of division elements when ε _i > δ at which the similarity decreases, and divides the curved surface. The number of elements varies actively depending on the size and curvature information of the provided design shape.

On the other hand, in the machining completeness evaluation using the principal curvature, the similarity between two curved surfaces is evaluated by comparing the K and H values of the corresponding points using the Gaussian curvature (K) and the average curvature (H). The processing completion degree of the curved surface member is calculated by the ratio of the total number of corresponding points, the number of points with high similarity, and the number of points with low similarity, and the K and H values of the points having the corresponding relationship are compared. When the difference is close to δ _K = δ _H = 0, it means that the similarity between the two curved surfaces is high, and is represented by a numerical value as in the processing degree formula.

  FIG. 11 is a shape in which the grid-like design shape and measurement shape utilizing the system of the present invention are in an optimum curved surface matching, and shows a stage before calculating the curved surface machining completeness. FIG. It illustrates the calculation of the degree of machining completion utilizing the system, and shows the evaluation result by the curved surface element division method of the degree of machining completion of the curved surface member. In FIG. 12, a quadrangular divided element means an element that deviates from the allowable error (δ), that is, a part that is not sufficiently processed. As shown in FIG. 12, if the number of quadrilateral division elements decreases, it means that the degree of completion of machining is high, and it can be said that the area where the quadrilateral division elements exist is an insufficiently machined portion.

  In this way, the curved surface shape that has been subjected to the evaluation of the curved surface alignment and the completeness of processing must be cut for the margin where the assigned margin remains unnecessarily. Therefore, the present invention minimizes the cutting work by presenting the optimum value of the cutting position. The new contour line caused by the difference in size between the curved shape-matched design shape and the measurement shape as described above must be projected so as to exist mainly on the surface of the measurement shape. At this time, a method of projecting the three-dimensional coordinates onto the coordinates of the xy plane is widely known. However, in the present invention, the measurement shape is a three-dimensional curved surface as well as the design shape. This can be properly projected.

  That is, in FIG. 13, the projection in the direction [1] is the same method as the projection onto the xy plane. When this method is used, the result of projecting the coordinates of the design shape to the coordinates of the wrong measurement shape is generated. Can do. Accordingly, in the present invention, as in [2], the position in the measurement shape is extracted using the normal vector at the corresponding position of the design shape. However, this method can be applied only to a member whose processing completeness has been evaluated. When the shape difference between two curved surfaces is large, many errors are included as in the method [1].

  The above description is only one embodiment for carrying out the processing completeness evaluation system and method for a curved member according to the present invention, and various modifications are possible without departing from the scope of the technical idea of the present invention. These are also within the technical scope of the present invention.

It is a figure which shows the margin information and chamfering information which the designer reflected the shrinkage | contraction margin value in the initial shape which opened the design shape of the three-dimensional curved surface flatly. It is a figure which shows the mode after the chamfering work performed to the outline of steel materials, and the cutting of a margin. It is a figure which shows the structure and flow of information of the process completeness evaluation system of the curved member by one suitable embodiment of this invention. FIG. 4 is a sequence diagram for evaluating the degree of processing completion of a curved member by the system of FIG. 3. It is a figure which shows the error and direction between design coordinates and measurement coordinates. It is a figure which shows the error and direction between design coordinates and measurement coordinates. It is a figure explaining the direction presentation method using the inner product of a vector. It is a figure shown for demonstrating the conventional method for curved surface matching which considered the constraint conditions, and the method of this invention. It is a figure which shows the form after curved surface matching which reflected the coordinate position and curved surface condition before curved surface matching using the system of FIG. It is an illustration figure in case the freedom degree of a restriction | limiting reference point is 0. It is an illustration figure which shows the matching state of the optimal curved surface in the state where a restriction | limiting reference point can move within an allowable error range using an error spherical area | region, when the freedom degree of a restriction | limiting reference point is not 0. It is an illustration figure of the optimal curved surface matching using the system of FIG. It is an illustration figure of calculation of the processing perfection degree using the system of FIG. It is a figure which shows the position change by a cutting position calculation method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Input module 20 Surface and point generation module 30 Optimum curved surface matching module 40 Processing perfection degree module 50 Cutting position and error calculation module 60 Processing information generation system 70 Cutting position display and cutting system 80 Storage device 90 Output device 100 Video display device 110 Printer

Claims (17)

A method for evaluating the degree of processing completion of a curved member,
Measuring a curved surface shape being processed or processed by a measuring device;
Inputting curved surface shape measurement data and design data to generate surfaces and points;
A curved surface matching stage that matches the designed curved surface shape with the measured curved surface shape, reflecting the marginal part of the hull manufacturing process and the specific constraints of the chamfering operation,
Calculating an error amount between curved surfaces;
Evaluating the processing completeness of the curved surface shape. The method of claim 1, comprising:
The method further comprises the step of transmitting information on the cutting position according to the error amount and the evaluation result to the cutting position display and the cutting system. The method of claim 1, comprising:
The measurement in the measurement step is performed by measuring three-dimensional point information, and measuring a position that matches the design curved surface shape data in a one-to-one correspondence relationship as measurement coordinates. The method of claim 1, comprising:
The measurement at the measurement stage is measured by three-dimensional point information, and if the correspondence between the design curved surface shape and the measured curved surface shape is not the same, the unspecified internal position and corner coordinates are measured as measurement coordinates. A method of measuring an internal position and a corner coordinate having the above-mentioned rule, or a method of precisely scanning a curved surface. The method of claim 3, comprising:
The measurement of the correspondence is as follows:
Obtaining data corresponding to the position to be measured from the design shape;
Measuring a position determined to be a corresponding coordinate in the curved surface shape to be measured based on the obtained data. The method of claim 1, comprising:
The calculation of the error amount is obtained not only from the distance error between the measurement coordinates and the design coordinates but also from the inner product of the vectors, and the point A at the corner of the design shape and the point B of the measurement shape corresponding to the point A, the design shape or When forming a triangular shape using the point C existing in the measurement shape, if each side is expressed by a vector of a, b, c, the angle θ between the vectors b and c is

And
A method characterized in that it can be determined whether the measurement coordinate is located outside or inside the design coordinate according to the calculated angle θ. The method of claim 1, comprising:
The curved surface matching step is a step of optimally matching one of the vertices in the corner of the curved surface shape that is constrained by using the Horn method as a constraint reference point, and is the same as the corner point to which the constraint is applied. A centroid which becomes a reference for translation is moved to a corner side which becomes a constraint condition by adding or superimposing the above. The method of claim 4, comprising:
The curved surface matching step is performed by an ICP (Interactive Closet Point) method when the correspondence relationship is not satisfied. The method of claim 1, comprising:
The step of evaluating the processing completeness of the curved surface shape includes analyzing the geometric distance or principal curvature between corresponding points of the curved surface and the direction thereof, the size of the divided area of the curved surface, and the similarity between the curved surface shapes through the curvature. A method characterized by judging. The method of claim 9, comprising:
The geometric distance between the corresponding points is the corresponding point of the design shape and the target shape, where P _i and Q _i each have the minimum distance between the shapes,

And
A method of evaluating the similarity of curved surfaces based on a relationship between a geometric distance ε _i at a specific corresponding point and a specific allowable error δ within a specific allowable error δ. The method of claim 7, comprising:
The constraint reference point is free to move within an allowable error range using an error spherical area. The method of claim 10, comprising:
After evaluating the similarity between the corresponding points, the percent completeness of the curved surface is

And
Here, D _T is the number of corresponding points between two shapes whose degree of perfection is evaluated, and D _ε is the number of corresponding points formed when ε _i > δ at which the degree of similarity decreases. Method. The method of claim 10, comprising:
After dividing the curved surface shape into specific criteria elements and evaluating the similarity of the divided elements, the percent completeness of the curved surface is

And
Here, E _T is the number of division elements between two shapes whose completeness is evaluated, and E _ε is the number of division elements when ε _i > δ at which the degree of similarity decreases, and divides the curved surface. The method is characterized in that the number of elements is actively changed according to the size and curvature information of the provided design shape. The method of claim 9, comprising:
In the evaluation of processing completeness using the main curvature, the Gaussian curvature and the average curvature of the corresponding points are compared to evaluate the similarity of the two curved surfaces, and the overall number of corresponding points and the similarity are A method of calculating the processing completeness of a curved surface member by the ratio of the number of high points and the number of low points. A system for evaluating the degree of processing completion of a curved member,
An input module in which measurement data and design information measured with respect to the curved surface shape of the curved member are input;
A surface and point generation module for generating coordinate positions relative to the surfaces and points of the measurement curved surface and the design curved surface;
An optimum curved surface matching module for performing curved surface matching and curved surface matching with constraint conditions;
A processing completeness module that presents the similarity between the design curved surface and the measured curved surface as a percentage value based on the result of curved surface matching,
A system comprising: a cutting position and an error calculation module for calculating a cutting position and an error when the numerical value presented from the processing completeness module is a curved surface completion condition. The system of claim 15, comprising:
The result obtained by performing the optimum curved surface matching by the optimum curved surface matching module is provided to a machining information generating system and utilized for generating machining information. The system of claim 15, comprising:
When the numerical value presented in the processing completeness module is not a curved surface completion condition, additional processing information is generated through a processing information generation system.

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