JP2007148811A - Tangent generation method, dead angle area setting method, visible area setting method, visibility determination method, design support device and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily generate a tangent through fixed procedure and/or perform setting of a dead angle area or visible area or determination for visibility. <P>SOLUTION: The tangent generation method for approximately generating a tangent passing an optional point on a plane and contacting with a curve on the plane from a selected side comprises a first process for setting a point set on the curve as a reference point; a second process for setting an approximate line passing through the optional point and the reference point; and a third process for replacing a point on the curve located on the selected side of the approximate line and farthest from the approximate line by the reference point. After executing the first process, the second process and the third process are alternately repeated a plurality of times, and an approximate line finally generated in the second process is taken as the tangent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tangential line creation method for approximately creating a tangent line that passes through an arbitrary point on a plane and touches a curved line on the plane from a selected side, a blind spot area setting method using the same, and a visible area setting method And a visual recognition determination method, a program for realizing these, a design support apparatus for executing the program, and a recording medium storing the program.

  Conventionally, in the vehicle design stage, from the viewpoint of safe driving, from the viewpoint of the driver sitting in the driver's seat, the range on the ground that becomes a blind spot by the hood etc. of the front part of the vehicle is calculated, or simulated to the height of the child For example, it is confirmed that a 1 m pole (a cylinder having a height of 1 m and a diameter of 0.3 m) can be visually recognized around the vehicle. Especially for the latter, according to the safety standards for road transport vehicles stipulated in the Road Transport Vehicle Law, the 1m pole 2m ahead of the car can be seen directly without using a mirror, etc. In addition, since it is required that the 1 m pole in contact with the left side surface (the right side surface in the case of a left-hand drive vehicle) be directly or indirectly visible with a mirror, an image, etc., confirmation at the design stage is required.

  Such calculation and confirmation are mainly performed using a CAD system. In the middle of the calculation, for example, a tangent line that sets a cross-sectional shape of the vehicle body and touches the cross-sectional shape (generally a curve) of the vehicle body from the viewpoint of the driver. The process of creating is required.

As a method of creating a tangent to a curve, for example, when (x, y) = (f (t), g (t)) is given in the orthogonal coordinates represented by the x-axis and the y-axis, (x−f A straight line satisfying (t ₀ )) / f ′ (t ₀ ) = (y−g (t ₀₎ ) / g ′ (t ₀ ) corresponds to a point (f (t ₀ ), g (t ₀ )) A method of making a tangent at a point to be known is known (for example, see Non-Patent Document 1).
New Mathematical Dictionary (Published by Osaka Book Co., Ltd., first edition: November 21, 1979)

  However, since the conventional method for creating a tangent is not a method for creating a tangent that passes through an arbitrary point, calculation is complicated if it is applied to the process of creating a tangent from the viewpoint of the driver. In addition, there are existing CAD systems having a function of creating a tangent, but problems such as not functioning when there is a break in the curve have been pointed out.

  In this way, it is necessary to create a tangent line passing through an arbitrary point with respect to the curve, particularly at the design stage of the automobile. Furthermore, considering the possibility of doing this by a program, it is desirable that a tangent can be easily created in a certain procedure.

  The present invention is to solve such a problem, to easily create a tangent in a certain procedure, and / or to set a blind spot area and a visible area using this, The main purpose is to determine whether or not visual recognition is possible.

  A first aspect of the present invention for achieving the above object is a tangential line creation method that approximately creates a tangent line that passes through an arbitrary point on a plane and touches a curve on the plane from a selected side. A first process using a point set on the curve as a reference point, a second process for setting an approximate line passing through an arbitrary point and the reference point, and a selected side of the approximate line. And a third step of replacing a point on the curve farthest from the approximate line with a reference point, and after executing the first step, the second step and the third step are alternately performed a plurality of times. Repeatedly, the approximate line created in the second process is finally tangent.

  According to the first aspect of the present invention, it is possible to easily create a tangent line with a certain procedure. Even when there is a break in the curve, a tangent can be created.

  In the first aspect of the present invention, the reference point set on the curve in the first step is preferably on the curve closest to a reference line passing through any point and set on the selected side of the curve. This is the point. In this way, since a straight line drawn from an arbitrary point toward the closest point to the reference straight line is likely to be a line close to the tangent, it can be brought closer to the tangent more quickly.

  A second aspect of the present invention is a computer-readable program that implements the tangential line creation method according to the first aspect of the present invention.

  According to a third aspect of the present invention, a CAD model in which a reference plane in a three-dimensional space and a viewpoint and a shielding object existing on the same side with respect to the reference plane are used to model the shielding object as viewed from the viewpoint. A blind spot area setting method for setting a blind spot area on a reference plane serving as a blind spot, wherein a plurality of planes passing through a viewpoint and including a normal line of the reference plane are set with different rotation angles around the normal line as a rotation center. The first process, the second process of creating a tangent line that passes through the viewpoint in each plane and touches the cross section of the shielding object by the tangent creation method of the first aspect of the present invention, and the second process in each plane A third step for obtaining an intersection point between the tangent line created in step 3 and the reference plane, an intersection point obtained in the third step in each plane, and a contact point obtained when creating the tangent line in the second step; Connect the intersections Sleep has a fourth step of setting the boundary of the blind spot region, the by, it is characterized in.

  According to the third aspect of the present invention, it is possible to easily set the blind spot area in a certain procedure.

  A fourth aspect of the present invention is a computer-readable program for realizing the blind spot area setting method according to the third aspect of the present invention.

  According to a fifth aspect of the present invention, a reference plane in a three-dimensional space and a viewing object of a predetermined size in contact with the viewpoint, the shielding object, and the reference plane that are on the same side of the reference plane are modeled. A viewable region setting method for setting a region in the reference plane of a visual target object that allows the visual target object to be visually recognized without a blind spot by a shielding object from the viewpoint using the CAD model, The first process of setting a plurality of planes including the normal line of the plane with different rotation angles with the normal line as the rotation center, and the tangent line passing through the viewpoint and touching the cross section of the shielding object in each plane The second process created by the tangent creation method of the first aspect and the visual target object created in the second process when the visual target object is moved along the reference straight line representing the reference plane in each plane. Is A third process of setting a crossing range on a reference line that crosses a tangent line, and a fourth process of setting a viewable region by connecting the crossing range in each plane. is there.

  According to the fifth aspect of the present invention, the visually recognizable area can be easily set by a certain procedure.

  A sixth aspect of the present invention is a computer-readable program that implements the viewable area setting method according to the fifth aspect of the present invention.

  According to a seventh aspect of the present invention, a reference plane in a three-dimensional space and a viewing object of a predetermined size in contact with the viewpoint, the shielding object, and the reference plane that are on the same side of the reference plane are modeled. Using the CAD model, when the position of the viewing object is arbitrarily set on a reference plane, it is determined whether the viewing object is visible from the viewpoint without causing a blind spot by the shielding object. A first determination process for determining a plane including a normal of a reference plane passing through a viewpoint and a visual recognition object, and a cross section of a shielding object passing through the viewpoint in the plane set in the first process. When the tangent line intersects with the visual recognition object in the second step of creating the tangent line tangent to the visual recognition object according to claim 1 and the plane set in the first process, the visual recognition object is Visual approval And determining, and a third step, and it is characterized in.

  According to the seventh aspect of the present invention, it is possible to easily determine whether or not visual recognition is possible in a certain procedure.

  An eighth aspect of the present invention is a computer-readable program that implements the visual recognition determination method according to the seventh aspect of the present invention.

  A ninth aspect of the present invention is a design support apparatus that executes the program of the second, fourth, sixth, or eighth aspect of the present invention.

  A tenth aspect of the present invention is a recording medium in which a program according to the second, fourth, sixth or eighth aspect of the present invention is stored.

  According to the present invention, it is possible to easily create a tangent line in a certain procedure and / or to set a blind spot area or a viewable area using the tangent line, and to determine whether or not it is viewable. it can.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a diagram schematically showing the configuration of a design support apparatus 10 that realizes the tangential line creation method, blind spot area setting method, and viewable area setting method of the present invention. The hardware configuration of the design support apparatus 10 includes a user terminal 30 and a server 40. The user terminal 30 includes, for example, a CPU 31, a ROM 32 that stores programs, and a readable / writable RAM 33 that temporarily stores data.

  The program 15 executed by the design support apparatus 10 includes a model creation unit 16 that creates a CAD (Computer-Aided Design) model from a three-dimensional shape or a two-dimensional shape, and a model use unit 17 that uses the created CAD model. Therefore, the tangent line creation method, blind spot area setting method, viewable area setting method, and viewability determination method according to an embodiment of the present invention are the tangent line creation function, blind spot area setting function, and visual recognition that are part of the model using unit 17. This is realized as a possible area setting function and a visual recognition determination method. The program 15 may be developed as a new program, but a function based on these methods may be added to an existing CAD program.

  The model creation unit 16 converts the designed three-dimensional shape into a CAD model. The CAD model refers to a model that represents the shape of a three-dimensional object with lines or surfaces (surfaces). This CAD model is stored in the server 40, for example.

  The model using unit 17 has various functions for use by the user using the created CAD model. Each of the above functions is stored in the ROM 32 as one of these functions. Hereinafter, these functions will be described.

  The tangent creation function is a function performed on a two-dimensional CAD model. In the tangent creation function, when a CAD model composed of an arbitrary point and a curve is given, a tangent that passes through the arbitrary point and touches the curve from the selected side is generated. The “selected side” is an identification of which one to create because there may be a plurality of lines that pass through an arbitrary point and touch the curve. Hereinafter, for the sake of convenience, when the curve is viewed from the reference point, the right side is the first side and the left side is the second side (see FIG. 2).

  Therefore, the tangent line creation function provides a tangent line creation flowchart of FIG. 3 when a CAD model of an arbitrary point and curve is given by the user and a reference straight line on the selected side passing through the arbitrary point is set. It is automatically performed by the CPU 31 in the procedure shown.

  First, the CPU 31 obtains a reference point on the curve closest to the reference line (S100). Since this process is a function existing in an existing CAD program, it may be used. Note that any point on the curve may be set as the first reference point without setting the above-described reference straight line.

  Next, an approximate line connecting the given arbitrary point and the reference point is created (S110), and a point on the curve farthest in the reference line direction is obtained from the created approximate line, and this is replaced with the reference point. (S120).

  Then, when the above-described S110 and S120 are alternately repeated a plurality of times (for example, three times) and it is determined that the number of times has been executed (S130), finally (in the above example, the third time) in S110 The generated approximate straight line is output as a tangent line (S140). As the number of times increases, the error decreases, but the processing speed decreases, and may be increased or decreased depending on the application. The determination in S130 is made with reference to the internal counter of the RAM 33 that is incremented for each execution.

  FIG. 4 shows how the tangent creation function is executed. In the figure, the approximation line (n) and the reference point (n) indicate that it has been set for the nth time in the repetition routine of S110 to S130.

  According to the tangent line creation function provided in the design support apparatus 10 described above, a tangent line can be easily created in a predetermined procedure. Even if there is a break in the curve, the result can be output.

  The blind spot area setting function is a function performed on a three-dimensional CAD model. In the blind spot area setting function, when a CAD model of a reference plane, a viewpoint, and a shielding object is given, a blind spot area on the reference plane that becomes a blind spot by the shielding object when viewed from the viewpoint is set. Note that the viewpoint and the shielding object cannot be created if they are not given as existing on the same side of the reference plane.

  The blind spot area setting function is automatically performed by the CPU 31 in accordance with the procedure shown in the blind spot area setting flowchart of FIG. 5 when the reference plane, the viewpoint, and the CAD model of the shielding object are given by the user.

  First, the CPU 31 sets a plurality of planes that pass through the viewpoint and include the normal line of the reference plane by changing each angle Δθ around the normal line as a rotation center (S200). In the following, all processing up to S220 is performed on each set plane.

  Next, a section of the shielding object on the plane is set, and a tangent line that passes through the viewpoint and touches the outer end line of the section of the shielding object is created by the tangent creation function of this embodiment (S210). At this time, the contact points to be created are connected to form the boundary line of the blind spot area on the shielding object side. The tangent is created twice from both sides of the first side and the second side in the tangent creation function.

  When the tangent is created, the intersection of the tangent and the reference plane and the contact point between the tangent and the outer end line of the cross section of the shielding object are obtained (S220).

Then, the intersection of the tangent line and the reference plane in each plane and the contact point between the tangent line and the outer edge line of the cross section of the shielding object are connected to set the boundary line of the blind spot area (S230).
FIG. 6 shows an example in which this blind spot range setting function is applied to the vehicle design stage. That is, a CAD model is created using the ground as a reference plane, the assumed driver's head position as a viewpoint, and the vehicle body design as a shielding object. It can be calculated. In this case, the reference line of the tangent line creation function used in this function may be a straight line extending in the horizontal direction from the viewpoint, for example. Further, if the set range of the plane in S200 is limited, for example, a blind spot area limited to a specific range in front of or behind the vehicle can be obtained. Further, this function can be extended to obtain a blind spot area on the hood, for example, with the hood portion as a reference plane.

  According to the blind spot area setting function provided in the design support apparatus 10 described above, the blind spot area can be easily set by a predetermined procedure.

  The viewable area setting function is a function performed on a three-dimensional CAD model. In the viewable area setting function, when a reference plane, a viewpoint, a shielding object, and a CAD model of the viewing object are given, the viewing object reference plane can be viewed from the viewpoint without causing a blind spot by the shielding object. Set the area at. In addition, when a viewpoint, a shielding object, and a visual recognition target object are not given as what exists on the same side of a reference plane, it cannot create.

  The visual recognition area setting function is automatically performed by the CPU 31 according to the procedure shown in the visual recognition area setting flowchart of FIG. 7 when a CAD model of a reference plane, a viewpoint, a shielding object, and a visual recognition object is given by the user.

  First, the CPU 31 sets a plurality of planes passing through the viewpoint and including the normal line of the reference plane by changing each angle Δθ around the normal line as a rotation center (S300). Hereinafter, all the processing up to S320 is performed on each of the set planes.

  Next, a cross section of the shielding object on the plane is set, and a tangent line that passes through the viewpoint and touches the outer edge of the cross section of the shielding object is created by the tangent creation function of the present embodiment (S310). The creation of the tangent line is performed twice from both sides of the first side and the second side in the tangent line creation function.

  When a tangent is created, the object to be viewed is moved on a straight line corresponding to the reference plane, and when the reference plane is regarded as the bottom, a straight line corresponding to the reference plane in which the upper end of the visible object is below the tangent line The upper range is set as the invisible range (S320). FIG. 8 shows how the invisible range is set.

  Then, the invisible range in each cross section is connected, an invisible area on the reference plane is set, and the visible area on the reference plane is output as an area excluding the invisible area (S330). .

  FIG. 9 shows an example in which the viewable area setting function is applied to the design stage of an automobile. That is, the ground plane is the reference plane, the assumed position of the driver's head is the viewpoint, the body design is a shielding object, and a 1m pole that imitates the height of a child (a cylinder with a height of 1m and a diameter of 0.3m). When a CAD model is created as a visual recognition object and this function is executed, it is possible to calculate the visible area of the 1 m pole on the ground where the 1 m pole can be seen without being blinded by the vehicle body (actually Since the 1 m pole has an area on the reference plane, the position (coordinates) of the 1 m pole on the reference plane is a problem. For example, the center of the circle is set as the coordinate of the 1 m pole. It can be moved on a straight line corresponding to the reference plane, and a point that is a reference for determining coordinates on a surface that is in contact with the reference plane is determined in advance for other shapes of the view target. It Re. Additionally, to set the area visible through the door mirror may be obtained regional composite to.). The reference line for the tangent line creation function used in this function is, for example, a straight line extending in the horizontal direction from the viewpoint. Furthermore, if the set range of the plane in S300 is limited, for example, a viewable region limited to a specific range in front of or on the side of the vehicle can be obtained.

  According to the viewable area setting function provided in the design support apparatus 10 described above, the viewable area can be easily set in a certain procedure.

  The visually recognizable determination function is a function performed on a three-dimensional CAD model. In the viewable area setting function, when a CAD model of a reference plane, a viewpoint, a shielding object, and a viewing object is given, it is determined whether or not the viewing object can be viewed from the viewpoint without causing a blind spot by the shielding object. In addition, when a viewpoint, a shielding object, and a visual recognition target object are not given as what exists on the same side of a reference plane, it cannot create.

  The visual recognition area setting function is automatically performed by the CPU 31 according to the procedure shown in the visual recognition area setting flowchart of FIG. 10 when a CAD model of a reference plane, a viewpoint, a shielding object, and a visual recognition object is given by the user.

  First, the CPU 31 sets a plane that includes the normal point of the reference plane and passes through the viewpoint and the specific point of the visual recognition object (S400).

  Next, a cross section of the shielding object on the plane is set, and a tangent line that passes through the viewpoint and touches the outer edge of the cross section of the shielding object is created by the tangent creation function of the present embodiment (S410). The creation of the tangent line is performed twice from both sides of the first side and the second side in the tangent line creation function.

  When the tangent is created, it is determined whether or not the visual target object intersects with the tangent, and the result is output as being visible when the object is intersected and when not being visible when not intersecting (S420 to 440).

  When this function is applied to the car and the 1 m pole exemplified in the above-described viewable area setting function, it can be determined whether or not the position (coordinates) on the reference plane (ground) of the 1 m pole is visible. . By applying this function, the position range of the 1m pole is set so that the 1m pole moves all within the range on the reference plane prepared in advance, and this function is repeatedly executed within this position range. It is also possible to determine whether there is a 1 m pole position that is invisible within the range. Further, a function may be added to the program 15 so as to realize this.

  According to the visually recognizable determination function provided in the design support apparatus 10 described above, it is possible to easily determine whether or not the visual target is visually recognizable by a certain procedure.

  As mentioned above, although the best mode for carrying out the present invention has been described using one embodiment, the present invention is not limited to such one embodiment, and within the scope not departing from the gist of the present invention, Various modifications and substitutions can be made to the above-described embodiment.

  For example, it is not necessary to provide all the functions provided in the design support apparatus 10 described above, and any one to three may be provided.

  In addition, each function provided in the design support apparatus 10 is automatically realized by the CPU 31 as a part of the model use unit 17, but an interactive creation function that requires a user's progress instruction or the like for each step. The operation of each step may be manually performed by the user using various functions of the model using unit 17. The CAD model may be input by any method.

  The present invention can be used at least in a vehicle design support apparatus.

It is the figure which showed typically the structure of the design support apparatus 10 which implement | achieves the tangent creation method etc. which concern on one Example of this invention. It is a figure which shows a mode that the side which touches is specified when creating a tangent with respect to a curve. It is a figure which shows an example of the tangent preparation flowchart which concerns on one Example of this invention. It is a figure which shows a mode that the tangent preparation function which concerns on one Example of this invention is performed. It is a figure which shows an example of the blind spot area | region setting flowchart which concerns on one Example of this invention. It is a figure which shows the example which applied the blind spot range setting function which concerns on one Example of this invention to the design stage of the motor vehicle. It is a figure which shows an example of the visual recognition area | region setting flowchart which concerns on one Example of this invention. It is a figure which shows a mode that the visual recognition impossible range is set. It is a figure which shows the example which applied the visible region setting function which concerns on one Example of this invention to the design stage of the motor vehicle. It is a figure which shows an example of the visual recognition determination flowchart which concerns on one Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Design support apparatus 15 Program 16 Model preparation part 17 Model utilization part 30 User terminal 31 CPU
32 ROM
33 RAM
40 servers

Claims (11)

A method of creating a tangent that approximately creates a tangent that passes through an arbitrary point on a plane and touches a curve on the plane from a selected side,
A first process using a point set on the curve as a reference point;
A second step of setting an approximate line passing through the arbitrary point and the reference point;
A third step of replacing a point on the curve on the selected side of the approximate line and farthest from the approximate line with the reference point;
After executing the first process, the second process and the third process are alternately repeated a plurality of times, and finally the approximate line created in the second process is set as a tangent line.
A tangent creation method characterized by this. The tangent creation method according to claim 1,
The reference point set on the curve in the first step is the point on the curve that is closest to the reference line that passes through the arbitrary point and is set on the selected side of the curve.
Tangent creation method.   A computer-readable program for realizing the tangential line creation method according to claim 1. The reference plane that becomes a blind spot by the shielding object when viewed from the viewpoint, using a CAD model in which a reference plane in a three-dimensional space and a viewpoint and a shielding object existing on the same side with respect to the reference plane are modeled. A blind spot area setting method for setting the top blind spot area,
A first step of setting a plurality of planes passing through the viewpoint and including the normal line of the reference plane with different rotation angles with the normal line as a rotation center;
In each plane, a second process of creating a tangent that passes through the viewpoint and is in contact with a cross section of the shielding object by the tangent creation method according to claim 1 or 2,
In each plane, a third process for obtaining an intersection point between the tangent created by the second process and the reference plane;
A fourth step of setting a boundary line of the blind spot region by connecting the intersection point obtained in the third step and the contact point obtained in creating the tangent line in the second step in each plane; Having
A blind spot area setting method characterized by that.   A computer-readable program for realizing the blind spot area setting method according to claim 4. Using a CAD model obtained by modeling a reference plane in a three-dimensional space and a viewing object having a predetermined size in contact with the viewpoint, the shielding object, and the reference plane that are on the same side of the reference plane, A viewable area setting method for setting an area in the reference plane of the visual recognition object that allows the visual recognition object to be visually recognized without a blind spot by the shielding object from a viewpoint,
A first step of setting a plurality of planes passing through the viewpoint and including the normal line of the reference plane with different rotation angles with the normal line as a rotation center;
In each plane, a second process of creating a tangent that passes through the viewpoint and is in contact with a cross section of the shielding object by the tangent creation method according to claim 1 or 2,
In each plane, when the viewing object is moved along a reference line representing the reference plane, the viewing object intersects with the tangent created in the second process. A third step of setting the range;
A fourth step of setting a viewable region by connecting the crossing ranges in each plane,
A visible region setting method characterized by the above.   A computer-readable program for realizing the viewable area setting method according to claim 6. Using a CAD model obtained by modeling a reference plane in a three-dimensional space and a viewing object having a predetermined size in contact with the viewpoint, the shielding object, and the reference plane that are on the same side of the reference plane, A visual recognition determination method for determining whether or not the visual recognition object is visible from the viewpoint without causing a blind spot by the shielding object when the position of the visual recognition object is arbitrarily set on a reference plane. And
A first step of setting a plane passing through the viewpoint and the visual recognition object and including a normal line of the reference plane;
A second step of creating a tangent that passes through the viewpoint and touches a cross section of the shielding object in the plane set in the first step by the tangent creation method according to claim 1,
In the plane set in the first process, when the tangent line intersects with the visual recognition object, it is determined that the visual recognition object is visible, a third process,
The visual recognition determination method characterized by the above.   The computer-readable program which implement | achieves the visual recognition determination method of Claim 8.   A design support apparatus for executing the program according to claim 3 or 5 or 7 or 9.   A recording medium in which the program according to claim 3 or 5 or 7 or 9 is stored.

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