JP4851542B2 - Route curve generation system, method, and program - Google Patents

Description

  The present invention relates to a technique for generating a curve that becomes a route of a deformable linear structure such as a cable passing between two passing points created by route design.

  Some devices for product development use cables as electrical wiring. The wire harness is obtained by processing an electric wire or a cable, and is an indispensable component in most of the devices including a plurality of units and in an automobile. Therefore, in recent years, software that supports route design for arranging cables (hereinafter referred to as “route design support software”) has been sold. Since CAD (Computer Aided Design) has been widely introduced in the manufacturing industry, the supporting software usually uses the device design data to design the route of the cable to be placed in the virtual space. . A design support system that supports cable route design is realized by causing a data processing device (computer) to execute the route design support software.

  The cable is a relatively flexible part. However, if the design is advanced without considering the cable, the product may need to be redesigned due to the cable. This is because it is easy to overlook defects such as forced cable bending, poor installation workability, and interference with other components. In the route design using the design data, it is possible to easily avoid such an oversight.

  Route design using the design support system is performed by designating (creating) a passing point that is a position through which a cable should pass. In specifying the position of the passing point, a position reference that is a reference position for specifying the position is usually selected as an attribute. The position reference includes a reference based on the origin of the coordinate system of the virtual space, a reference based on another passing point, and a reference based on a component (model) arranged in the virtual space.

  The cable route is determined by obtaining a curve passing through each passing point. There is no calculation formula that can completely express the curve (even if it exists, it is considered to be very complicated and difficult). For this reason, as a curve, it is common to obtain a parametric curve, particularly a Bezier curve. For this reason, at each passing point, in addition to its position, it is common to manage the passing direction of the cable as passing point information. The route curve generation system is mounted on a design support system for generating a route (curve) through which a cable passes.

  The route curve generation system generates a curve every two consecutive passing points. When a Bezier curve is generated as the curve, one or more control points are arranged in addition to the two passing points. In general, when a more complicated curve can be generated, the order (the number of control points) is increased. A Bezier curve is generally expressed as follows.

Where N is the order. P (k): k-th control point.
In a Bezier curve, only the first and last control points of the control points pass, and the control points between them are only used to determine the curve shape of the curve. For this reason, one of the two passing points is used as the first control point (start point) and the other is used as the last control point (end point). By using two passing points in that way, a Bezier curve that passes through them can be generated.

An actual cable (including a wire harness) may have a length constraint in addition to a bending constraint.
A real cable cannot be bent beyond a certain value determined by the material, length, and thickness of the cable. In the virtual space, the local bend of the cable route is expressed by a radius of curvature similar to an arc as shown in FIG. In FIG. 1, R is a radius of curvature, P1 to P3 are passing points, and LC is a cable route. In order to satisfy the bending constraint condition, it is necessary that the radius of curvature of the entire route be greater than or equal to the minimum radius of curvature. On the other hand, the length constraint condition occurs when it is desired to calculate the cable length necessary to connect the passing points with the minimum length, or when it is desired to connect the passing points with a specified length.

  Some conventional route curve generation systems express a route with a cubic Bezier curve. This cubic Bezier curve has two control points in addition to the two passing points (control points) of the start point and the end point. The two control points are arranged as shown in FIG. 2 in the passing direction at the start point and the end point in order to maintain the continuity of the curve. This makes it very easy to handle. In FIG. 2, P1 is a passing point (control point) as a starting point, P2 is a passing point (control point) as an end point, V1 and V2 are passing directions of the passing points P1 and P2, and C2 is a passing direction of the passing point P1. A control point C3 arranged on V1 is a control point arranged on the passing direction V2 of the passing point P2 (more precisely, on the opposite direction of the passing direction V2 from the passing point P2). In this way, the control point is indicated by a symbol string with a leading “C” and a numerical value indicating the order from the starting control point (passing point P1) as a subsequent symbol. Thereby, for example, “C2” indicates a control point positioned next to the control point C1 of the starting point which is the passing point P1. Others are the same.

  With a cubic Bezier curve, it is likely that an appropriate route cannot be determined in the virtual space even between passing points where cables can actually be arranged. For example, as shown in FIG. 3, when the passing points P1 and P2 exist in the vicinity and their passing directions V1 and V2 are parallel or nearly parallel, a circle SM having a minimum radius of curvature between the passing points P1 and P2. Even if a route LC having a larger radius of curvature actually exists, as a result of arranging two control points C2 and C3 in the virtual space as shown in FIG. 4, the minimum radius of curvature in the route LC is smaller than the circle SM. It corresponds to the circle SR. For this reason, in conventional route curve generation systems that can take into account bending constraints and line lengths, it is common to use a Bezier curve of the fourth or higher order. Hereinafter, the actual minimum radius of curvature in the route LC is referred to as “minimum root radius of curvature” in order to distinguish it from the minimum radius of curvature which is a cable bending constraint, and the minimum radius of curvature itself is referred to as “default radius”. I will decide.

In a fourth-order Bezier curve, for example, a fifth-order Bezier curve, four control points are arranged in addition to the two passing points P1 and P2. As a result, when a fifth-order Bezier curve is used, convergence calculation that repeats rearrangement of four control points is performed until a route (Bezier curve) that satisfies all the constraints to be satisfied is obtained. Examples of the arrangement method of the four control points include the following. A specific description will be given with reference to FIG.
(1) The passing points as the starting point and the ending point are set as control points C1 and C6, respectively.
(2) In order to maintain the continuity of the curve, the control points C2 and C5 need to be on line segments parallel to the passing direction passing through the control points C1 and C2, respectively. Therefore, the control point C2 has a predetermined offset (hereinafter, for convenience, “the control point C2 (passing point P1) in the passing direction, and the control point C5 from the control point C6 (passing point P1) in the direction opposite to the passing direction”). (Referred to as “first offset”).
(3) A vector from the control point C1 to the control point C2 is defined as A, and a vector from the control point C6 to the control point C5 is defined as B. In addition, the temporary midpoint TM is set at a position that is separated from the midpoint M of the straight line connecting the control points C2 and C5 by an arbitrary offset amount h in the direction of the combined vector of the vectors A and B.
(4) A position separated from the temporary midpoint TM by a predetermined offset (hereinafter referred to as a second offset for convenience) to the control point C2 side in a direction parallel to the linear direction connecting the control points C2 and C5. Control point C3, and conversely, the control point C4 is arranged at a position away from the control point C5 by a second offset.

The arrangement of the control points C2 to C5 as described above is an initial arrangement. The convergence calculation is performed while changing the offset amount h.
FIG. 7 is a flowchart of route generation processing executed by a conventional route curve generation system. The route generation process is a process executed to perform the above convergence calculation and specify the arrangement of four control points from which a route (Bézier curve) that satisfies all the constraints to be satisfied is obtained. Constraints to be satisfied include bending constraints (minimum route radius of curvature greater than the default radius), length constraints (for example, target cable lines to connect between passing points below a specified length) Length (hereinafter referred to as “target line length”) or less). Here, the generation process will be specifically described with reference to FIG.

  First, in step S1, a target line length and a default radius (indicated as “minimum curvature” in the figure) between the passing points are designated as initial values. Such designation may be performed by referring to data set in advance by the user, or the distance between passing points may be used as an initial value of the target line length. In the subsequent step S2, α is multiplied by the target line length (for example, a value such as 0.25 (= α) times is used) as an initial value of the offset amount h, and convergence (repetition) is performed while changing the offset amount h. ) Calculate. After the convergence calculation is completed, the process proceeds to step S3.

  In step S3, a route (Bézier curve) whose length becomes the target line length due to a change in the offset amount h is determined. If there is a route having a target line length, the determination is OK, and the process proceeds to step S5. Otherwise, the determination is NG, the process proceeds to step S4, the setting for increasing the target line length is performed, and then the process returns to step S1. Thereby, in the execution of the next step S1, a target line length longer than the previous time is designated, or a value obtained by multiplying the current target line length by β (for example, 1.25 (= β) times) is set as a new target. Set as line length.

  In step S5, the minimum route curvature radius is determined. The determination is made only for the route having the target line length. If there is a route whose minimum route curvature radius is greater than or equal to the default radius, the determination is OK, and the route generation processing is performed here. finish. If not, that is, if the length does not reach the target line length, or if the minimum route curvature radius is equal to or less than the default radius even in the route of the target line length, the determination is NG, and the process proceeds to step S4. Thereby, the target line length is reset (e.g., extending the line length), and the convergence calculation is performed again.

  As is apparent from FIGS. 5 and 6, the length of the route tends to become shorter as the offset amount h becomes smaller. However, as shown in FIG. 5, when the passing points P1 and P2 are located in the vicinity, even if the route LS that satisfies the bending constraint condition actually exists, the route LC generated in the virtual space is It tends to occur that the bending constraint is not satisfied. In addition, as shown in FIG. 6, depending on the orientations of the vector A and the vector B, there may be a portion where the route is locally bent. In that case, it is likely that the route LC that satisfies the bending constraint condition cannot be generated.

  It is important to satisfy the length constraint. However, it is less important than the bending constraints. This is because it is relatively easy to change the length of the entire cable, but the bending constraint must be satisfied. For this reason, it is considered important to be able to more reliably generate a route that satisfies the bending constraint conditions. By making it possible to generate such a route more reliably, it is considered that the route design can be performed more easily and quickly for the user (designer).

  The deformable linear structure attached to the apparatus is not only relatively thin such as the cable (including an optical cable), an electric wire, or a wire harness, but also has a relatively thick cylindrical shape, for example. The cylindrical linear structure is attached to allow a fluid such as air to flow or to pass another linear structure inside. It can be said that making a route design easier and faster can be applied to all linear structures having bending constraints regardless of the type of the linear structure.

The linear structure is not only attached between units mounted on one device (product) such as an electric product or an automobile, but may be attached between a plurality of devices arranged at different locations. . For this reason, the route design may be performed to attach a linear structure between a plurality of different devices. Even if such a plurality of apparatuses are used, if a linear structure having bending constraints is attached, it is necessary to design a route so as to satisfy the constraints.
JP 2004-127925 A Japanese Patent Laid-Open No. 2004-172088 JP-A-2005-100913 JP 2000-284130 A

An object of the present invention is to provide a technique for making it possible to more reliably generate a route that satisfies a bending constraint condition.
Both of the route curve generation systems according to the first and second aspects of the present invention are based on the premise that a curve serving as a route of a deformable linear structure passing between two passing points created by route design is generated. The following means are provided.

A route curve generation system according to a first aspect includes first control point arrangement means for arranging control points necessary for generating a curve from passage point information respectively defined at two passage points, Based on the positional relationship between the control points arranged by the control point arrangement means, control by one of the second control point arrangement means for rearranging the control points and the first and second control point arrangement means The point arrangement is an initial arrangement, and while changing the arrangement of one or more control points, a curve generation unit that generates a curve between two passing points, and an evaluation of the curve generated by the curve generation unit is performed. Curve evaluation means for extracting a curve that satisfies a predetermined condition from the curve evaluation means , the curve evaluation means as a curve that satisfies the predetermined condition, by changing the arrangement of one or more control points once, Whether the curve satisfies the constraints to be met before and after the change The curve generating means can arrange one or more control points within a range in which the two curves can be obtained when the curve evaluation means extracts two curves. The curve between the two passing points is generated while changing .

  The route curve generation system according to the second aspect includes control point arrangement means for arranging control points necessary for generating a curve from the passage point information respectively defined at two passage points, and control by the control point arrangement means. The first curve generation means for generating a curve between two passing points while changing the arrangement of one or more control points, and the curve generated by the first curve generation means A curve that evaluates and extracts two curves constituting a boundary that changes whether or not a constraint condition that the curve should satisfy before and after the change is changed by one change of the arrangement of one or more control points When the evaluation means and the curve evaluation means extract two curves, the arrangement of one or more control points is changed more finely than the first curve generation means within the range where the two curves are obtained. Second curve generation to generate a curve between passing points Comprising the stage, and the curve selecting means for selecting an optimal curve between two passing points from among the curve where the second curve generating means to generate a.

  The route curve generation method according to the first and second aspects of the present invention is used to generate a curve that is a route of a deformable linear structure passing between two passing points created by route design by a computer. Assuming that it is used, a curve is generated as follows.

In the route curve generation method according to the first aspect, control points necessary for generating a curve are arranged based on the passing point information respectively defined at two passing points, and the positional relationship between the arranged control points is based on the positional relationship. Then, the control points are rearranged, the initial arrangement of the control points for generating the curve is confirmed, and the arrangement of one or more control points is changed from the determined initial arrangement. Generate a curve between passing points, evaluate the generated curve , and change the arrangement of one or more control points as a curve satisfying a predetermined condition from the curve before and after the change. When two curves constituting a boundary where whether or not a constraint condition to be satisfied by the curve changes are extracted and two curves are extracted, one or more within the range in which the two curves are obtained are extracted. Curve between two passing points while changing the control point layout more finely Generated.

  In the route curve generation method according to the second aspect, control points necessary for generating a curve are arranged from the passing point information respectively defined at two passing points, the arrangement is set as an initial arrangement, and one or more While changing the arrangement of control points, generate a curve between two passing points, evaluate the generated curve, and change the arrangement of one or more control points once, before and after the change. When two curves constituting a boundary where whether a curve satisfies a constraint condition to be satisfied are extracted and two curves are extracted, one or more control points are within a range where the two curves are obtained. The curve between the two passing points is generated again while changing the arrangement of the above in more detail than the previous time, and the optimal curve between the two passing points is selected again from the generated curves.

Program of the present invention, assume that to be executed by a computer used in the construction of the root curve generation system for generating a route to become curved deformable linear structures passing between two passing points created by the route design The following functions are realized on the computer.

In this program, the initial placement of two passing points in the passing point information defined respectively, and a control point located ability to place the necessary control points in order to generate the curves, the arrangement of the control points of the control point arrangement function The first curve generation function for generating a curve between two passing points and the curve generated by the first curve generation function are evaluated while changing the arrangement of one or more control points. A curve evaluation function for extracting two curves constituting a boundary where whether or not a constraint condition to be satisfied by the curve changes before and after the change by one change of the arrangement of the control points described above, and a curve evaluation When two curves are extracted by the function, the arrangement of one or more control points is changed more finely than the first curve generation function within the range where the two curves are obtained, and the curve between the two passing points is changed. A second curve generation function to be generated; And the curve selection function for selecting an optimal curve between two passing points from among the generated curve by curve generating function of, to realize.

When the present invention is applied, the control points necessary for generating a curve (route) are arranged from the passage point information respectively defined at the two passage points, and based on the positional relationship between the arranged control points, Control points are rearranged as necessary, and the initial placement of the control points for generating the curve that becomes the root of the deformable linear structure is determined, and one or more from the determined initial placement While changing the arrangement of control points, generate a curve between two passing points, evaluate the generated curve , and arrange one or more control points as a curve satisfying a predetermined condition from the curve Thus, two curves constituting a boundary where whether or not a constraint condition to be satisfied by the curve changes before and after the change are extracted.

  By performing the rearrangement as necessary, the initial arrangement can be made more desirable. It can also be optimized. Accordingly, it is possible to further reduce the possibility that an appropriate curve cannot be generated depending on the positional relationship between the control points (the position of the passing point itself and the passing direction thereof). For this reason, when a constraint condition to be satisfied by a curve such as a bending constraint condition is set as a predetermined condition, a curve satisfying the constraint condition can be generated more reliably.

  When the present invention is applied, control points necessary for generating a curve are arranged from the passing point information respectively defined at two passing points, and the arrangement is set as an initial arrangement, and one or more control points are arranged. The curve between two passing points is generated while changing the value, the generated curve is evaluated, and the constraint that the curve must satisfy before and after the change is made by changing the arrangement of one or more control points once. When two curves that make up the boundary where whether or not the condition is changed are extracted, and two curves are extracted, the arrangement of one or more control points within the range where the two curves are obtained from the previous time A curve between two passing points is generated again with fine changes, and an optimum curve is selected between the two passing points from the generated curves again.

  In this way, the fineness of changing the arrangement of one or more control points is changed, and the generation of a curve by making the change relatively finely is limited to a narrow range. For this reason, an optimal curve can be obtained with a smaller amount of calculation.

It is a figure explaining the expression method of the bending of the route | root of the cable (linear structure) produced | generated on virtual space. When a route between two passing points is generated with a cubic Bezier curve, it is a diagram illustrating two control points arranged in addition to the two passing points. It is a figure explaining the suitable route which actually exists when passage points P1 and P2 exist in the neighborhood, and those passage directions V1 and V2 are parallel or close to parallel. It is a figure explaining the route produced | generated on virtual space when the passage points P1 and P2 exist in the vicinity and those passage directions V1 and V2 are parallel or close to parallel. It is a figure explaining the positional relationship between the passing points from which the conventional route curve generation system which produces | generates a route with a 5th-order Bezier curve cannot produce | generate an appropriate route (the 1). It is a figure explaining the positional relationship between the passing points from which the conventional route curve generation system which produces | generates a route with a 5th-order Bezier curve cannot produce | generate an appropriate route (the 2). It is a flowchart of the route production | generation process which the conventional route curve production | generation system performs. It is a figure explaining the functional structure of the cable route creation system carrying the route curve generation system by this Embodiment. It is a figure explaining the rearrangement of the control point performed in the case of the positional relationship between the passing points shown in FIG. It is a flowchart of a route generation process. It is a figure which shows an example of the hardware constitutions of the computer which can implement | achieve the cable route creation system carrying the route curve generation system by this Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 8 is a diagram showing a functional configuration of a cable route creation system (hereinafter abbreviated as “creation system”) equipped with a route curve generation system according to the present embodiment. The creation system 2 is for designing the route of a cable that is a deformable linear structure, and the route curve generation system according to the present embodiment is realized on the creation system 2.

  An input device 1 and an output device 3 that are operated by the user are connected to the creation system 2. The input device 1 includes a pointing device such as a mouse and a keyboard, for example. The output device 3 is a display device such as a liquid crystal display device. As a result, the creation system 2 edits the passing point according to the operation of the input device 1 performed by the user for route design, and displays the edited result or the route designed cable on the output device 3. It has become.

The creation system 2 includes a cable management unit 21, a three-dimensional model management unit 22, a passing point management unit 23, a display unit 24, and a route generation unit 25.
The cable management unit 21 is for managing the route design for each cable. The three-dimensional model management unit 22 is for managing design data (model data) of parts arranged in an apparatus designed in three dimensions. The model data is stored in a model data database (hereinafter “DB”) 22a and managed by the verification model management unit 22b. The passing point management unit 23 is for managing passing points in units of cables under the control of the cable management unit 21. For passing point information management, a passing point position individual managing unit 23a, a passing direction managing unit 23b, and a passing direction reference coordinate managing unit (hereinafter referred to as “coordinate managing unit”) 23c are provided. The display unit 24 is for displaying an image on the output device 3. An image for displaying the created passing point is generated by the passing point display unit 24a.

  The route generation unit 25 generates a route of the cable for which the route is designed, and the route curve generation system according to the present embodiment is realized as the route generation unit 25. The route generation unit 25 includes a control point management unit 25a, a type determination unit 25b, a curve calculation unit 25c, and a curve determination unit 25d.

  FIG. 11 is a diagram illustrating an example of a hardware configuration of a computer capable of realizing the creation system 2. Prior to the detailed description of FIG. 8, first, the configuration of a computer capable of realizing the creation system 2 will be specifically described. In order to avoid confusion, the creation system 2 will be described on the assumption that it is realized by a single computer having the configuration shown in FIG.

  The computer shown in FIG. 11 includes a CPU 61, a memory 62, an input device 63, an output device 64, an external storage device 65, a medium drive device 66, and a network connection device 67, which are connected to each other via a bus 68. It has become. The configuration shown in the figure is an example, and the present invention is not limited to this.

  The CPU 61 controls the entire computer. The memory 62 is a memory such as a RAM that temporarily stores a program or data stored in the external storage device 65 (or the portable recording medium 69) during program execution, data update, or the like. The CPU 61 performs overall control by reading the program into the memory 62 and executing it.

  The input device 63 has, for example, an interface connected to the input device 1 such as a keyboard and a mouse, or all of them. A user operation on the input device 1 is detected, and the detection result is notified to the CPU 61.

  The output device 64 is, for example, a display control device connected to the output device 3 of FIG. The data sent under the control of the CPU 61 is output on the output device 3 of FIG.

  The network connection device 67 is for communicating with an external device via a network such as an intranet or the Internet. The external storage device 65 is, for example, a hard disk device. Mainly used for storing various data and programs.

The storage medium driving device 66 accesses a portable recording medium 69 such as an optical disk or a magneto-optical disk.
The route design result is stored in the memory 62 or the external storage device 65. The design data including the model data of the device in which the cable is arranged is stored on the external storage device 65 or the recording medium 69. Here, it is assumed that the data is stored on the external storage device 65 for convenience. In this case, the DB 22a is stored on the external storage device 65.

  The route curve generation system (creation system 2) according to the present embodiment is realized by the CPU 61 executing a program (hereinafter referred to as “design support software”) equipped with necessary functions. The design support software may be recorded and distributed in, for example, the recording medium 69, or may be acquired by the network connection device 67. Here, it is assumed that the data is stored on the external storage device 65.

  In the assumption as described above, the cable management unit 21 is realized by the CPU 61, the memory 62, the input device 63, the external storage device 65, and the bus 68, for example. The passing point management unit 23, the route generation unit 25, and the 3D model management unit 22 are realized by, for example, the CPU 61, the memory 62, the external storage device 65, and the bus 68. The display unit 24 is realized by, for example, the CPU 61, the memory 62, the output device 64, the external storage device 65, and the bus 68.

  In the present embodiment, when a user newly creates a passing point via the input device 1 or changes the position of an existing passing point, the route of the route between the passing points to be generated is as follows. Generate. This will be described in detail with reference to FIG. 5, FIG. 6, and FIG. In order to explain with reference to FIGS. 5 and 6 as well, the same or basically the same components are denoted by the same reference numerals, and the Bezier curve is assumed to be a fifth order.

First, a basic control point arrangement method will be described. The arrangement method is basically the same as that of the conventional route curve generation system, and will be specifically described with reference to FIG.
The section for generating the route is between two passing points. Of the two passing points, the passing point P1 corresponding to the parent is set as the starting point side, and the passing point P1 is set as the control point C1. The control point C2 is arranged at a position away from the passing point P1 by a predetermined offset (hereinafter also referred to as “first offset”) in the passing direction. The passing direction is vector A.

  Of the two passing points, the passing point P2 corresponding to the child is the end point side, and the passing point P2 is the control point C6. The control point C5 is arranged at a position away from the passing point P2 by a first offset in the direction opposite to the passing direction. The direction opposite to the passing direction is a vector B.

  Next, the provisional midpoint TM is set at a position separated from the midpoint M on the straight line connecting the control points C2 and C5 by an arbitrary offset amount h in the direction of the combined vector of the vector A and the vector B. The provisional midpoint TM is set by creating a composite vector of the vector A and the vector B from the midpoint M, and extending the straight line in the direction opposite to the perpendicular line extending from the tip of the composite vector to the straight line connecting the control points C2 and C5. It is also possible to go to a position separated by an offset amount h.

  The control point C3 is located at a position that is a predetermined offset (hereinafter also referred to as a second offset) toward the control point C2 in a direction parallel to the linear direction connecting the control points C2 and C5 from the temporary midpoint TM. Place. On the contrary, the control point C4 is arranged at a position away from the provisional midpoint TM by the second offset toward the control point C5.

  The arrangement of the control points C2 to C5 as described above is an initial arrangement. In the convergence calculation performed while changing the offset amount h, there is a possibility that a route that satisfies the bending constraint condition cannot be calculated when the positional relationship between the passing points P1 and P2 is as shown in FIGS. Is expensive. For this reason, in this Embodiment, arrangement | positioning of a control point is operated as follows.

The control point placement operation is performed when the placement conditions for the operation are satisfied. Two arrangement conditions are provided as follows.
(1) The combined vector of the vector A and the vector B is in the first range (the lower limit value of the first range ≦ the combined vector / vector A ≦ the upper limit value in the first range) compared to the vector A, and The linear distance between the control points C2 and C5 is equal to or less than the first threshold value (linear distance / first offset ≦ first threshold value) compared to the first offset.
(2) An angle formed by a line segment C2C3C4 connecting the control points C2 to C4 with a straight line (an angle formed by a straight line connecting the control points C2 and C3 and a straight line connecting the control points C3 and C4), and the control points C3 to C5 At least one of the angles formed by the line segment C3C4C5 connecting the lines with each other is a reference angle or less.

  For example, as shown in FIG. 5, the arrangement condition 1 represents a situation where the passing points P1 and P2 are located in the vicinity and the directions of the vectors A and B are relatively parallel. In such a situation, the minimum route radius of curvature of the route LC tends to be small. For this reason, arrangement | positioning is operated by making 1st offset shorter. Thereby, the control points C2 and C5 are rearranged closer to the control points C1 and C6, respectively. By performing such rearrangement, it becomes possible to generate a route LS that satisfies the bending constraint condition as shown by a broken line in FIG. Therefore, a route satisfying the bending constraint can be generated more reliably.

  The combined vector is also small when the vectors A and B are close to each other, that is, when the passing points P1 and P2 are connected by a straight line or a curve close to a straight line. In such a case, there is no particular problem even if the distance between the control points C2 and C5 is short. This is why the first range is not used as a threshold value. In the present embodiment, 2 is used as the first threshold, and when the arrangement condition 1 is satisfied, the first offset is ¼ of the original.

  The rearrangement is performed on both the control points C2 and C5, but only one of them may be performed. This is because even if only one of them is rearranged, a route that satisfies the bending constraint condition can be generated with higher probability. When only one of the objects is to be rearranged, it is desirable that one of them finds an angle formed by the vector A and the vector B with a straight line connecting the passing points P1 and P2, respectively, and selects the smaller one.

  For example, as shown in FIG. 6, the arrangement condition 2 assumes a case where the curve of the route is locally tight. In the case shown in FIG. 6, the angle formed by the line segment C2C3C4 is small, and the angle formed by the line segment C3C4C5 is large. From this, if the angle formed by the line segment C2C3C4 is equal to or smaller than the reference angle, the distance (second offset) between the temporary midpoint TM and the control point C3 is shortened, and the angle formed by the line segment C2C3C4 is increased. . Conversely, if the angle formed by the line segment C3C4C5 is equal to or smaller than the reference angle, the distance (second offset) between the temporary midpoint TM and the control point C4 is shortened, and the angle formed by the line segment C3C4C5 is increased. By performing such rearrangement, even in the case shown in FIG. 6, a route LC that satisfies the bending constraint condition can be generated as shown in FIG. As is clear from this, a route that satisfies the bending constraint condition can be generated more reliably.

  The convergence calculation performed while changing the offset amount h is performed after confirming whether the initial arrangement satisfies one of the arrangement conditions 1 and 2, and performing necessary relocation according to the confirmation result. Accordingly, a route that satisfies the length constraint condition in addition to the bending constraint condition can be generated more appropriately and reliably.

  Arrangement conditions on which control points should be rearranged are not limited to the arrangement conditions 1 and 2 described above. More arrangement conditions may be prepared. The rearrangement method may be determined for each prepared arrangement condition. For example, the angle formed by the line segment C2C3C4 is made larger if the angle formed by the line segment C3C4C5 is sufficiently large, the angle formed by the straight line connecting the midpoint M and the temporary midpoint TM and the straight line connecting the control points C2 and C5. It may be performed by operating.

  The arrangement conditions 1 and 2 are assumed to generate a fifth-order Bezier curve. The setting of the conditions such as the arrangement conditions 1 and 2 can be similarly performed if the Bezier curve is a fourth-order or higher. If the Bezier curve is a fourth or higher order, the rearrangement (arrangement operation) method as described above can be easily applied.

Returning to FIG. 8, the operations of the units 21 to 25 for realizing the above-described route design support will be described in detail.
The cable management unit 21 analyzes an operation performed on the input device 1, recognizes the content of the user instruction, and performs processing according to the recognition result. As a result of the processing, route design is realized, and as a result of the design, data relating to a passing point created by editing is generated and stored by the passing point management unit 23.

  The passing point management unit 23 creates a passing point information management table (hereinafter referred to as a “passing point position table”) for each cable to be route-designed by editing the passing point by the user, and updates it as necessary. To do. The passing point position table stores passing point information such as the position, the passing direction, and the position reference for each passing point. The update is performed under the control of the cable management unit 21, for example.

  The passing point position individual management unit 23a stores / updates each data related to the position standard such as a relative position coordinate, a standard position coordinate, a reference model name, and a reference model relative position. The passing direction management unit 23b determines the passing direction. The passing direction reference coordinate management unit 23c stores and updates data for each axis indicating the determined passing direction. All of these are performed according to the user's instruction content recognized by the cable management unit 21. It supports route design through passing point editing.

  The route generation unit 25 refers to the passing point position table, generates a route for the cable designed by the user for each passing point having a parent-child relationship, and sends the generation result to the display unit 24. . Thereby, the cable along the route is displayed on the output device 3 as a design result.

  The control point management unit 25a manages control points for calculating a route (curve) between passing points, and sets and changes the arrangement. The type determination unit 25b determines the type corresponding to the arrangement from the arrangement (initial arrangement) of the control points set by the control point management unit 25a. The determination of the type is performed by extracting an arrangement that satisfies one of the above arrangement conditions 1 and 2. The control point management unit 25a changes (operates) the arrangement of the control points according to the determination result.

  The curve calculation unit 25c calculates a curve according to the currently set control point arrangement. At the time of iterative calculation, the control point management unit 25a sequentially changes the offset amount h and notifies the curve calculation unit 25c of the control point arrangement.

  The curve determination unit 25d calculates the minimum route curvature radius and the curve length of the curve calculated for each control point arrangement by the curve calculation unit 25c, and arranges control points (ie, offsets) that form a curve greater than the default radius as a threshold. Extract quantity h). The extraction result is notified to the control point management unit 25a. After the notification, the control point management unit 25a limits the range in which the offset amount h should be changed with a finer width, and changes the offset amount h within the range. Set the control point layout. The curve calculation unit 25c calculates a route (curve) for each setting arrangement. From the calculation result, the curve determination unit 25d finally selects one route that is considered to be most desirable. The route thus selected is displayed on the output device 3 via the display unit 24.

  FIG. 10 is a flowchart of route generation processing. In the route generation process, when a passing point is newly generated or the position is changed by the user, between the passing point and the passing point located immediately before (parent passing point), and / or immediately after It is executed to generate a route connecting between the passing points (child passing points). This is realized by the CPU 61 shown in FIG. 11 reading the design support software stored in the external storage device 65 into the memory 62 and executing it. Next, with reference to FIG. 9, a process for realizing the operation of the above-described creation system 2 will be described in detail.

  First, in step S11, a target line length of a cable between passing points (a target curve distance between passing points) and a default radius are designated. Such designation may be performed with reference to data set in advance by the user, or may be performed using the distance between passing points as an initial value of the target line length. The data is data managed by the passing point management unit 23, for example. In the subsequent step S12, 0.25 times the target line length is set as the initial value of the offset amount h, and convergence (repetition) calculation is performed while changing the offset amount h. Step S13 is performed during the convergence calculation.

  In step S13, every time the offset amount h is changed, a route is generated, and the line length and the minimum route curvature radius are calculated. In step S14 after the convergence calculation is completed, it is determined whether or not a route (curve) having a minimum route radius of curvature greater than or equal to the default radius is established (generated) in at least one of the changed offset amounts h. . When one or more such routes exist, it is determined that the route has been established, and the process proceeds to step S16. Otherwise, it is determined as “none”, the process proceeds to step S15, and the allowable maximum line length is set as the target line length. Thereafter, the process returns to step S12.

  In step S16, it is determined whether or not the minimum offset curvature radius is greater than or less than the default radius in the changed offset amount h. If there is no offset amount h whose minimum route curvature radius is less than the default radius, or if there is no boundary where the minimum radius is greater than or less than the default radius, it is determined as “None”, and for example, the line length in the route satisfying the bending constraint condition After saving the shortest one as the final result, the route generation process is terminated. If none of them is present, that is, if there is one or more boundaries where the minimum radius of curvature is greater than or equal to the default radius, it is determined as “present” and the process proceeds to step S17.

  In step S17, the offset amount h at that boundary is extracted, the minimum offset amount h1 whose minimum route curvature radius is greater than or equal to the default radius, its line length L1, and the minimum route curvature radius is less than the default radius. The maximum offset amount h2 and the line length L2 are further extracted. Thereby, the line length L2 is set as the target line length, and the offset amount h1 is set as the initial offset amount h. When there are a plurality of borders, the one having the smallest offset amount h is adopted.

  In step S18 following step S17, a route is generated each time the offset amount h is changed while changing the offset amount h with a finer width than in step S13, and the line length and the minimum route curvature radius are calculated. Thus, after the route having the minimum route curvature radius equal to or larger than the default radius and the minimum offset amount h is stored as the final result, the route generation processing is terminated.

  In this way, in the present embodiment, the first convergence calculation (step S13) in which the width for changing the offset amount h is relatively large is performed, and then the second is obtained by reducing the width from the calculation result. Convergence calculation (step S18) is performed as necessary. As a result, the final result can be obtained more quickly while maintaining accuracy as compared with the conventional route curve generation system (FIG. 7) that performs convergence calculation with the same change width.

  The determinations in steps S14 and S16 are made by preparing a variable irc and substituting a value to be substituted for the variable irc in step S13. FIG. 10 also shows the value of the variable irc from which the determination results of steps S14 and S16 are obtained.

  In the present embodiment, the control points to be rearranged are executed before the route generation processing is executed, but this is for obtaining a more desirable final result more quickly. . From the execution result of the route generation process, it may be determined whether or not the control points should be rearranged, and the rearrangement may be performed according to the determination result.

  In addition, the deformable linear structure is intended for cables (including wire harnesses, optical cables, etc.), but may be a different type as long as it is a deformable linear structure. An object to be route-designed, that is, an object to which a linear object is attached may be an object including a plurality of devices arranged at different locations.

Claims (8)

In a route curve generation system for generating a curve that becomes a route of a deformable linear structure passing between two passing points created by route design,
First control point arrangement means for arranging control points necessary for generating the curve from the passage point information respectively defined by the two passage points;
Second control point placement means for rearranging the control points based on the positional relationship between the control points placed by the first control point placement means;
The control point placement by one of the first and second control point placement means is an initial placement, and the curve between the two passing points is generated while changing the placement of one or more control points. Curve generating means for
A curve evaluation unit that performs evaluation of the curve generated by the curve generation unit and extracts a curve that satisfies a predetermined condition from the curve , and
The curve evaluation means changes whether or not a constraint condition to be satisfied by the curve before and after the change is changed by one change of the arrangement of the one or more control points as a curve that satisfies the predetermined condition. Can extract two curves that make up the boundary,
When the curve evaluation means extracts the two curves, the curve generation means changes the arrangement of the one or more control points within a range in which the two curves are obtained, Generate the curve between passing points,
A route curve generation system characterized by that. The route curve generation system according to claim 1,
When the curve generation unit generates a Bezier curve of fourth order or higher as the curve, the second control point arrangement unit is configured by the first control point arrangement unit except for the two passing points. Rearrangement is performed on at least one of the control points. A route curve generation system according to claim 2,
The second control point arrangement means shortens at least one of two linear distances between the two passing points and a control point located next to each of the two passing points, and the 4 The rearrangement is performed by performing at least one of increasing the angle of a line segment connecting three control points among the three control points with a straight line. A route curve generation system according to claim 3,
The second control point arrangement means considers at least a straight line distance between two control points located next to the two passing points, and a straight line between the two passing points and the two control points. The rearrangement is performed to shorten at least one of the distances. In a route curve generation system for generating a curve that becomes a route of a deformable linear structure passing between two passing points created by route design,
Control point arrangement means for arranging the control points necessary for generating the curve from the passage point information respectively defined by the two passage points;
First curve generation means for generating the curve between the two passing points while changing the arrangement of one or more control points, with the arrangement of the control points by the control point arrangement means being an initial arrangement;
The curve generated by the first curve generation means is evaluated, and whether or not a constraint condition to be satisfied by the curve before and after the change is satisfied by one change of the arrangement of the one or more control points. A curve evaluation means for extracting two curves constituting a changing boundary;
When the curve evaluation means extracts the two curves, the arrangement of the one or more control points is changed more finely than the first curve generation means within a range in which the two curves are obtained. Second curve generating means for generating a curve between two passing points;
A curve selecting means for selecting an optimal curve between the two passing points from the curves generated by the second curve generating means;
A route curve generation system comprising: In a route curve generation method for generating a curve that is a route of a deformable linear structure passing between two passing points created by route design by a computer,
From the passing point information respectively defined by the two passing points, the control points necessary for generating the curve are arranged,
Based on the positional relationship between the arranged control points, rearrange the control points, determine the initial arrangement of the control points in generating the curve,
From the determined initial arrangement, changing the arrangement of one or more control points, generating the curve between the two passing points,
The generated curve is evaluated, and as a curve satisfying a predetermined condition from the curve , a constraint condition that the curve should satisfy before and after the change by changing the arrangement of the one or more control points once Extract two curves that make up the boundary that changes whether or not
When the two curves are extracted, the curve between the two passing points is generated while finely changing the arrangement of the one or more control points within a range where the two curves are obtained .
A route curve generation method characterized by that. In a route curve generation method for generating a curve that is a route of a deformable linear structure passing between two passing points created by route design by a computer,
From the passing point information respectively defined by the two passing points, the control points necessary for generating the curve are arranged,
Generating the curve between the two passing points while changing the arrangement of one or more control points, with the arrangement being an initial arrangement;
The generated curve is evaluated, and a boundary that changes whether or not a constraint condition to be satisfied by the curve before and after the change is changed by one change of the arrangement of the one or more control points is formed 2 Extract one curve,
When the two curves are extracted, the curve between the two passing points is generated again while changing the arrangement of the one or more control points within a range where the two curves can be obtained. ,
Again, select an optimal curve between the two passing points from the generated curves.
A route curve generation method characterized by that. A computer used to construct a route curve generation system that generates a curve that is a route of a deformable linear structure passing between two passing points created by route design.
A control point arrangement function for arranging control points necessary for generating the curve from the passage point information respectively defined by the two passage points;
A first curve generation function for generating the curve between the two passing points while changing the arrangement of the one or more control points while setting the arrangement of the control points by the control point arrangement function as an initial arrangement;
The curve generated by the first curve generation function is evaluated, and whether or not a constraint condition to be satisfied by the curve before and after the change is satisfied by one change of the arrangement of the one or more control points. A curve evaluation function that extracts two curves constituting a changing boundary;
When the two curves are extracted by the curve evaluation function, the arrangement of the one or more control points is changed more finely than the first curve generation function within a range where the two curves are obtained. A second curve generation function for generating a curve between two passing points;
A curve selection function for selecting an optimal curve between the two passing points from the curves generated by the second curve generation function;
A program to realize

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