JP3663346B2 - Chipping simulation method, chipping simulation apparatus, and vehicle design method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chipping simulation method, a chipping simulation apparatus, and a vehicle design method using the simulation, in particular, a chipping simulation for estimating a chipping occurrence position in a vehicle body based on shape data of a vehicle outer shape and a vehicle design reflecting the simulation. Regarding the method.
[0002]
[Prior art]
When a vehicle travels, gravel or rock salt on the road is spun up by the rotation of the tire of the vehicle, which may hit the body of the vehicle. This phenomenon is called chipping, and the painted surface of the body is generally damaged by chipping. And since the scratches caused by chipping are deep and reach the substrate, the core of point rust is, so conventionally, with chipping resistant materials etc., the way of scratching is reduced or the spread of rust when scratched It was necessary to take measures such as suppressing
[0003]
In order to minimize such chipping, the automobile manufacturer collects data related to the chipping occurrence position and damage due to chipping in advance and analyzes it to prevent body chipping from being reduced or reduced. In order to prevent damage to the body even if chipping occurs, the placement of protectors (protective tape, etc.) was examined before the vehicle was put on the market.
[0004]
Conventionally, in order to collect the above data, the vehicle is actually run to generate chipping, or chipping is generated using a chipping test apparatus disclosed in JP-A-10-54780. Necessary data was collected.
[0005]
[Problems to be solved by the invention]
However, in the past, data related to chipping occurrence position and damage due to chipping was collected using actual vehicles, so the data was acquired after the prototype vehicle was completed or immediately before the actual production of the vehicle started. It becomes from. Therefore, chipping countermeasures must be followed-up countermeasures, and the manufacturing process is provided with a process for countermeasures against chipping, and new parts for countermeasures are required. There was a problem of causing a delay. Furthermore, since it is very difficult to change the body shape as a countermeasure against chipping after the prototype vehicle is completed or after the start of actual production, it is necessary to use a protector, etc. It had the problem of reducing the completeness of the body design that was evaluated as “sculpture”.
[0006]
The present invention has been made in view of the above problems, and easily obtains data on the chipping occurrence position and damage caused by chipping in the vehicle body at the vehicle design stage, and reflects the result on the vehicle at an early stage. An object of the present invention is to provide a chipping simulation method, a chipping simulation apparatus, and a vehicle design method using the simulation.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the chipping simulation method of the present invention includes: A chipping simulation method for performing vehicle chipping simulation using a computer, A shape acquisition step for acquiring outer shape data of the vehicle, and a trajectory drawn by a virtual particle bouncing up by the tire of the vehicle, the trajectory calculating a relative flight trajectory as seen from the traveling vehicle within a predetermined range And calculating a crossing position between the relative flight trajectory and the outer shape data, and estimating a chipping occurrence position in the body of the vehicle.
[0008]
Further, the chipping simulation apparatus of the present invention is a trajectory drawn by the shape acquisition means for acquiring the outer shape data of the vehicle and the virtual particles jumped up by the tire of the vehicle, and is relative to the vehicle as it travels. Trajectory calculation means for calculating a flight trajectory within a predetermined range; and chipping estimation means for calculating an intersection position between the relative flight trajectory and the outer shape data and estimating a chipping occurrence position in a vehicle body. Features.
[0009]
Here, the shape data of the vehicle outer shape includes not only the shape data of the outer plate surface of the vehicle and the back surface of the floor of the vehicle, but also the data regarding the shape and characteristics regarding the tire. Virtual particles are simulating gravel, rock salt, and other objects that may be present on the road, which can jump up during normal road driving. It can be selected and set. Usually, the particles present on the road are flipped upward (in a vertical plane with respect to the tire contact surface) by contact with the tire. The jumping height varies depending on the size and mass of the particles. At this time, since the vehicle is actually traveling, when viewed from the traveling vehicle, the bounced particles fly in a parabola and relatively fly backward, but the locus changes depending on the height of the jump. Further, the predetermined range is a range in which the particles can collide, for example, a range including the side surface of the vehicle and the floor back surface of the vehicle.
[0010]
According to this configuration, since the chipping occurrence position in the vehicle body can be estimated by calculating the intersection position between the relative flight trajectory and the vehicle outer shape data, data relating to chipping can be easily collected without using an actual vehicle. be able to.
[0011]
In order to achieve the above object, in the present invention, the trajectory calculating step is a trajectory surface that approximates the relative flight trajectory of the same height, and one end is in contact with a tire outer peripheral surface, A planar relative flight trajectory in which the elevation angle in the direction determined by the vehicle speed and the vertical jump height of the virtual particle body with respect to the tire contact surface is sequentially calculated, and the chipping estimation step includes the planar relative flight trajectory. The chipping occurrence position in the body of the vehicle is estimated based on the intersection position of the vehicle and the external shape data.
[0012]
According to this configuration, since the relative flight trajectory can be approximated as a straight trajectory, it is easy to calculate the intersection position between the relative flight trajectory and the shape data. It should be noted that various jumping heights of the virtual particles can be taken into consideration by sequentially changing the elevation angle of the planar relative flight trajectory with respect to the tire contact surface. Further, the elevation angle with respect to a certain jumping height can be determined, for example, by the direction of the combined vector of the traveling speed vector of the vehicle and the jumping speed vector of the particles.
[0013]
In order to achieve the above object, according to the present invention, in the above configuration, the trajectory calculating step sequentially moves a starting point position of the relative flight trajectory from a tire contact surface along a tire outer peripheral surface. And
[0014]
Here, the starting point position is sequentially moved along the tire outer peripheral surface from the tire ground contact surface along the tire outer peripheral surface from the lower end position of the tire to the tire center height, for example. This is because, as described above, the height of the particles that are flipped up by the tire varies depending on the size and the like. That is, it means that correction is applied in consideration of the fact that the smaller the granular body, the higher the jumping height, and the smaller the granular body, the relative flight trajectory passes through a high position from the tire contact surface.
[0015]
According to this configuration, it is possible to calculate a locus closer to actual particle flying, and it is possible to improve the reliability of calculating the chipping occurrence position. When approximating the relative flight trajectory with a planar trajectory plane and changing its elevation angle, calculate the trajectory closer to the actual particle flight by simultaneously changing the elevation angle and the start point position. Can do.
[0016]
In order to achieve the above object, according to the present invention, in the above configuration, the chipping estimation step is based on an intersection angle between the outer surface defined by the outer shape data and the relative flight trajectory. It is characterized by estimating the size of.
[0017]
When the flying particles collide with the outer surface of the vehicle, if the mass of the particles is the same, the closer the contact angle is to a right angle, the more the kinetic energy possessed by the particles is transmitted to the collision site. That is, the damage on the outer surface is increased to form deeper scratches. On the contrary, the shallower the contact angle, the more the particles become scratched and the less kinetic energy is transferred, and the scratches are also superficial. Therefore, by using the intersection angle between the outer surface and the relative flight trajectory, the magnitude of chipping damage can be easily estimated without using an actual vehicle.
[0018]
In order to achieve the above object, the present invention is characterized in that, in the above configuration, the chipping estimation step performs identification display for each estimated magnitude of chipping damage.
[0019]
Here, it is preferable that the identification display is, for example, a color-coded display or a different mark for each degree of damage.
[0020]
According to this configuration, it is possible to easily recognize the chipping occurrence position and the magnitude of damage caused thereby.
[0021]
In order to achieve the above object, the vehicle design method of the present invention includes: A vehicle design method for designing a vehicle using a computer, comprising: A shape acquisition step for acquiring outer shape data of the vehicle, and a trajectory drawn by a virtual particle bouncing up by the tire of the vehicle, the trajectory calculating a relative flight trajectory as seen from the traveling vehicle within a predetermined range A calculation step, a chipping estimation step for calculating a crossing position between the relative flight trajectory and the outer shape data, and estimating a chipping occurrence position in a vehicle body, and the outer shape based on the estimated chipping occurrence position. The steps to fix Execute It is characterized by that.
[0022]
According to this configuration, at the vehicle design stage, based on the estimated chipping occurrence position, for example, a body shape that prevents the granules and the body outer shape from coming into contact with each other or reduces the degree of damage even if they come into contact with each other. Can be considered at an early stage, and efficient vehicle design can be performed, and it is not necessary to provide a chipping countermeasure process in the actual vehicle manufacturing process, etc. A delay can be avoided.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention (hereinafter referred to as embodiments) will be described with reference to the drawings.
[0024]
FIG. 1 shows a schematic block diagram of a chipping simulation apparatus 10 (referred to as a simulation apparatus 10) for realizing the chipping simulation method of the present embodiment. The simulation apparatus 10 includes a shape data acquisition unit 12 that acquires shape data of a vehicle outer shape before the vehicle shifts to an actual trial production and the like, and particles that can cause chipping in an actual vehicle body, such as gravel Grain data setting unit 14 for setting data related to rock salt and the like, a calculation unit 16 for virtually calculating the chipping occurrence position and the damage caused by chipping based on the acquired and set data, and the simulation result are displayed. It comprises a display unit 18 such as a display.
[0025]
The shape data acquired by the shape data acquisition unit 12 is data relating to the outer shape of the vehicle. For example, wire frame data that is design data of the vehicle body and data indicating the continuous surface of the body, in particular, the side surface portion of the vehicle and the underfloor This is data relating to the part, and is obtained from, for example, CAD data. The shape data also includes data relating to the tire used (data on the diameter, thickness, material, etc. of the tire). Moreover, the granule data setting part 14 is provided with various characteristic data regarding the virtual object (virtual granule) which may exist on roads, such as gravel and rock salt as mentioned above. The data can be arbitrarily selected and set, for example, the size, mass, material, etc. of the virtual particles. This is because the place where the vehicle travels frequently varies depending on the type of vehicle to be simulated. For example, sedan and compact type vehicles often travel on paved roads, and gravel on the road is relatively small. In addition, RV vehicles and 4WD vehicles have many opportunities to travel off-road, and relatively large gravel exists on the road. When a granule is splashed up in contact with a tire, the granule is flipped up (within a range of about 40 ° to the left and right within a vertical plane with respect to the tire contact surface). The jumping height varies depending on the position, and the virtual flight trajectory described later changes. Therefore, the granular data setting unit 14 can make detailed settings according to the simulation target. Of course, since there are particles of various sizes, masses, and materials on the paved road, the particle data may be set in a wide range such as a diameter of 1 mm to 7 mm.
[0026]
On the other hand, the calculation unit 16 includes a relative flight trajectory calculation unit 20 that calculates a relative flight trajectory as seen from the traveling vehicle, which is a trajectory drawn by a virtual particle bounced up by a tire of the vehicle, and the relative flight. Based on the range setting unit 22 for setting the calculation range to be calculated by the track calculation unit 20 and the calculated relative flight track and shape data, the intersection position between the two is calculated, and the chipping occurrence position in the body of the vehicle is estimated. A chipping estimation unit 24, a damage estimation unit 26 for estimating damage to a wound caused by the generated chipping, a display control unit 28 for controlling a display form so that the estimated chipping occurrence position and damage damage can be easily recognized, and the like. Contains. Of course, an equivalent apparatus can be constructed by recording a program for executing each function described above on a recording medium and installing the program in an existing computer or the like.
[0027]
Subsequently, a specific simulation procedure will be described. First, the shape data acquisition unit 12 acquires three-dimensional solid shape data of the vehicle 30 as shown in FIG. 2 from CAD data or the like. Subsequently, for example, a particle diameter of 0.5 to 5 mm is set in the particle data setting unit 14 as the particle data that the vehicle 30 may jump up.
[0028]
The range setting unit 22 performs a more efficient simulation by limiting a calculation range described later by simply determining a range where chipping can occur from the acquired shape data of the vehicle 30. In general, in the case of a passenger car, chipping on the side surface of the vehicle occurs in a substantially triangular region in which the ground contact position of the front tire and the upper part of the wheel house of the rear tire are connected by a straight line. Therefore, for example, as shown in FIG. 2, the range is set by setting the elevation angle from the tire contact surface with respect to the rear of the vehicle 30.
[0029]
By the way, as described above, when the granule is flipped up in contact with the tire, the granule is flipped up (in the range of about 40 ° left and right within the vertical plane with respect to the tire ground contact surface), The jumping height varies depending on the size and mass of the granule, and the jumping speed also changes. At this time, assuming that the speed of the vehicle 30 is constant regardless of the size of the particles, the smaller particles move along a higher trajectory, and the particles move as if protruding from a higher position. Therefore, in the present embodiment, the relative trajectory of the particles as seen from the vehicle that actually travels, that is, the relative flight trajectory of the smallest particle that is jumped to the highest position among the relative flight trajectories, the starting point is illustrated. As shown in FIG. 2, it is assumed that the position has moved upward along the outer peripheral surface of the tire, for example, the position moved to the center height of the tire (up to 1/4 of the rear outer periphery of the tire). Therefore, when setting the elevation angle, the elevation angle is set based on the position moved upward along the outer peripheral surface of the tire (for example, the position moved to the center height of the tire).
[0030]
In the present embodiment, it is desirable that the relative flight trajectory calculation unit 20 accurately calculates the parabolic trajectory of the relative flight trajectory trajectory of the granule based on the mass of the granule, the jumping speed of the granule, the vehicle speed, and the like. However, since the shape of the outer plate surface of the vehicle 30 has a three-dimensional curved surface, the calculation for obtaining a parabola in all cases leads to complicated processing. Therefore, in this embodiment, as shown in FIG. 3, a locus plane 32 that approximates a relative flight locus having the same height is set. One end of the locus surface 32 is in contact with the outer peripheral surface of the tire 34. Therefore, when the range is set by the range setting unit 22 described above, as shown in FIG. 3, the trajectory surface 32 indicating the relative flight trajectory has one end surface of the outer peripheral surface of the tire 34, for example, the center height of the tire. It is in the range of the elevation angle (for example, 15 °) set based on the shape data with reference to the vertical position. At this time, the direction of the trajectory plane 32 (the direction of the vector along the trajectory plane 32) depends on the vehicle speed vector (direction parallel to the tire ground contact surface) and the vertical jump speed vector (on the tire ground contact surface). (The direction perpendicular to the direction) is determined by a combined vector and is sequentially calculated within a set elevation angle range. Note that, as described above, the particles that are flipped up by the tire are scattered within a range of about 40 ° to the left and right within the vertical plane with respect to the tire contact surface, but the particles that are involved in chipping of the body side surface are The trajectory surface 32 in the case of performing the chipping simulation of the body side surface has a substantially rectangular surface shape, and its width protrudes by a predetermined amount (for example, 10 cm) from the tire width. Thus, the length is desirably up to the rear of the wheel house of the rear tire.
[0031]
Accordingly, as shown in FIGS. 4A to 4D, the relative flight trajectory calculation unit 20 moves the trajectory surface 32 from the ground contact surface 36 (see FIG. 3) of the tire 34 to the outer peripheral surface of the tire 34. By sequentially changing the elevation angle to a predetermined angle, it is possible to cover changing relative flight trajectories according to various conditions (size, mass, etc.) of virtual particles.
[0032]
Subsequently, as shown in FIGS. 4A to 4D, the chipping estimation unit 24 calculates the intersection position between the locus surface 32 (relative flight locus) and the shape data when the locus surface 32 moves. To do. This intersection position is a generation position where the virtual particle collides with the vehicle body and chipping occurs. In accordance with the calculated intersection position, the display control unit 28 superimposes and displays the chipping occurrence position on the vehicle displayed on the display unit 18 such as a display. The crossing position between the locus surface 32 and the outer shape data is indicated by “×” as shown in FIG. In the case of FIG. 2, it has shown that chipping has generate | occur | produced in the front part of the wheel house of a rear tire, and the lower part of a door.
[0033]
As described above, it is possible to easily estimate the chipping occurrence position in the vehicle body by calculating the intersection position between the external shape data that can be obtained from the CAD data and the like in the vehicle body design stage and the relative flight trajectory. Data on chipping can be collected at an early stage without using an actual vehicle.
[0034]
In the present embodiment, the chipping simulation apparatus 10 can further estimate the degree of damage received by the vehicle 30 due to chipping. When the flying particle collides with the outer surface of the vehicle 30, if the mass is the same, the closer the contact angle is to a right angle, the more kinetic energy that the particle has is transmitted to the collision site. That is, the damage on the outer surface is increased to form deeper scratches. On the contrary, the shallower the contact angle, the more the particles become scratched and the less kinetic energy is transmitted, and the scratches are also superficial. In FIG. 2, the contact angle between the outer plate surface 30 a of the vehicle 30 and the relative flight trajectory in an arbitrary continuous section AA of the vehicle 30 is as shown in FIG. 5. In FIG. 5, the contact angle θ1 between the relative flight trajectory a and the outer plate surface 30a, the contact angle θ6 between the relative flight trajectory f and the outer plate surface 30a, and the like are such that the contact angle of the granule 38 is shallow and the damage to the outer plate surface 30a is also affected. I understand that it is small. Conversely, the contact angle θ4 between the relative flight trajectory d and the outer plate surface 30a, the contact angle θ5 between the relative flight trajectory e and the outer plate surface 30a, and the like are such that the contact angle of the granules 38 is close to a right angle and the damage received by the outer plate surface 30a. Can be seen to be large.
[0035]
In the present embodiment, the damage estimation unit 26 can easily calculate the contact angle between the shape data of the outer plate surface 30a and the relative flight trajectory at the chipping occurrence position. For example, if the contact angle is less than 10 °, soft damage, contact An angle of 10 ° or more is estimated as hard damage. Of course, it is also possible to perform estimation by further classifying angles. As shown in FIG. 6, it is desirable to identify and display the chipping occurrence position as the damage estimation result. As shown in FIG. 6, hard damage H occurs at the front part of the rear wheel house and the rear end of the front wheel house closest to the front tire, and soft damage S occurs at the lower part of the door and the upper part of the wheel house of the rear tire. It has occurred. When color display is possible with an output device such as the display unit 18 or a printer, it is preferable to perform color display.
[0036]
The magnitude of damage varies depending on, for example, the strength and hardness of the coating applied to the outer plate surface 30a. It is desirable to correct the magnitude of damage based on these data.
[0037]
In this way, it is possible to estimate the degree of damage due to chipping together with the position where chipping occurs by calculating the intersection position and intersection angle between the shape data available at the vehicle body design stage and the relative flight trajectory. It is possible to consider the change of the body shape at an early stage by feeding back the acquired chipping data to the design so that the body and the body outline do not contact each other and damage is reduced even if contacted. Vehicle design can be performed. Of course, it is also possible to repeat the simulation while sequentially changing the body shape, and a body shape with little influence of chipping can be obtained in a short time.
[0038]
By the way, chipping occurs not only on the body side surface of the vehicle 30 but also on the back surface of the floor of the vehicle, causing spot rust and the like. In the present embodiment, as with the case of the body side surface, the chipping occurrence position and damage can be estimated for the back surface of the vehicle floor.
[0039]
As described above, when a granule is flipped up in contact with a tire, the granule is flipped up (within a range of about 40 ° to the left and right within a vertical plane with respect to the tire contact surface). When performing simulation of chipping on the body side surface, it is sufficient that the trajectory of the particles involved in chipping is close to the body side surface, and the trajectory surface 32 used at that time has a substantially rectangular shape. However, as shown in FIG. 7 (a), it is necessary to set a trajectory surface 40 having a predetermined angle (for example, 40 °) for at least the inside of the tire 34 with respect to the back surface of the floor. Since there is a small portion belonging to the floor back surface on the tire outer side, the trajectory surface 40a is set as a part of the trajectory surface 40 also on the tire outer side.
[0040]
The relative flight trajectory calculation unit 20 in FIG. 1 makes the trajectory plane 40 relative to all by sequentially changing the elevation angle in the direction determined based on the vehicle speed and the fluid jumping speed, as in the method shown in FIG. Calculate the flight trajectory. By changing the locus plane 40 in the same way for both the left and right wheels, it is possible to calculate a relative flight locus for the entire back surface of the vehicle 30. In addition, since the area of the locus | trajectory surface 40 is large regarding a floor back surface, as shown to FIG.7 (b)-(f), while forming the locus | trajectory surface 40b with a small area, and rotating with respect to a floor back surface sequentially, A necessary relative flight trajectory may be calculated by changing the angle in the elevation direction.
[0041]
After calculating the relative flight trajectory, as in the case of the vehicle side surface, the chipping estimation unit 24 estimates the chipping occurrence position and the damage estimation unit 26 estimates the damage, and the display control unit 28 shows in FIG. Such display of the chipping occurrence position on the back surface of the vehicle 30 and the degree of damage on the back surface of the floor due to chipping are displayed on the display unit 18. In this case as well, the display form may be identification by the type of mark or identification by color change.
[0042]
The user of the simulation apparatus 10 changes the body shape of the vehicle 30 on the shape data based on the occurrence position of chipping as described above and the degree of damage caused by the chipping, and again as described above if necessary. Thus, the occurrence of chipping and damage can be simulated to obtain a body shape that does not cause chipping or a body shape that can minimize the effects of chipping.
[0043]
In this way, at the body shape design stage, the chipping occurrence position and the degree of damage due to chipping can be easily recognized, so the optimum body that can prevent or suppress chipping while emphasizing the body design. The shape design can be performed at an early stage. In this case, there is no need for countermeasures for chipping in the actual vehicle production process, and it is possible to reduce the vehicle manufacturing cost and the manufacturing speed.
[0044]
In the above-described embodiment, the trajectory plane is set wide so that the simulation can be performed without distinction of the form of the vehicle, for example, sedan, compact type, RV car, 4WD, etc., but it is suitable for each vehicle. If the setting is performed, a highly reliable simulation result can be obtained more quickly.
[0045]
In addition, since chipping, especially chipping related to the floor, may cause noise and vibration, the location of chipping and the degree of damage caused by chipping can be used as data when measures against occurrence of noise and vibration are taken. .
[0046]
【The invention's effect】
According to the present invention, since the chipping occurrence position in the vehicle body is estimated by calculating the intersection of the relative flight trajectory and the external shape data, it is possible to easily collect data related to chipping without using an actual vehicle. In addition, by using the angle of intersection between the outer surface and the relative flight trajectory, it becomes possible to easily estimate the magnitude of damage when chipping occurs without using an actual vehicle. Therefore, the vehicle design can be changed easily and accurately.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating a configuration concept of a simulation apparatus that realizes a simulation method according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram for explaining a relative flight trajectory of the simulation method according to the embodiment of the present invention.
FIG. 3 is an explanatory diagram illustrating a locus plane of a simulation method according to an embodiment of the present invention.
FIG. 4 is an explanatory diagram showing a change in the elevation angle direction of the locus plane of the simulation method according to the embodiment of the present invention.
FIG. 5 is an explanatory diagram for explaining estimation of chipping damage in the simulation method according to the embodiment of the present invention.
FIG. 6 is an explanatory diagram illustrating a display example of a chipping occurrence position and chipping damage on the vehicle side surface of the simulation method according to the embodiment of the invention.
FIG. 7 is an explanatory diagram for explaining a trajectory plane when a floor back surface simulation is performed by the simulation method according to the embodiment of the present invention.
FIG. 8 is an explanatory diagram illustrating a display example of a chipping occurrence position and chipping damage on the vehicle floor rear surface in the simulation method according to the embodiment of the invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Chipping simulation apparatus, 12 Shape data acquisition part, 14 Granule data setting part, 16 Calculation part, 18 Display part, 20 Relative flight locus calculation part, 22 Range setting part, 24 Chipping estimation part, 26 Damage estimation part, 28 Display Control unit, 30 vehicle, 32 trajectory plane, 34 tires.

Claims (7)

A chipping simulation method for performing vehicle chipping simulation using a computer,
On the computer,
A shape acquisition step for acquiring vehicle outer shape data;
A trajectory calculating step for calculating a relative flight trajectory as seen from the traveling vehicle, which is a trajectory drawn by the virtual particles bounced up by the tire of the vehicle, and
Calculating a crossing position between the relative flight trajectory and the outer shape data, and estimating a chipping occurrence position in a vehicle body; and
Chipping simulation method characterized by to run. The method of claim 1, wherein
The locus calculating step includes:
It is a trajectory plane that approximates the relative flight trajectory of the same height, one end of which is in contact with the outer peripheral surface of the tire, and the elevation angle in the direction determined by the vehicle speed and the vertical jump height of the virtual particle body sequentially with respect to the tire ground contact surface Calculate the changing surface relative flight trajectory,
The chipping estimation step includes:
A chipping simulation method, wherein a chipping generation position in a vehicle body is estimated based on an intersection position between the planar relative flight trajectory and the outer shape data. The method according to claim 1 or claim 2, wherein
The locus calculating step includes:
A chipping simulation method, wherein a starting position of the relative flight trajectory is sequentially moved from a tire ground contact surface along a tire outer peripheral surface. The method according to any one of claims 1 to 3,
The chipping estimation step includes:
A chipping simulation method characterized in that the magnitude of chipping damage is estimated based on an intersection angle between an outer surface defined by the outer shape data and the relative flight trajectory. The method of claim 4, wherein
The chipping estimation step includes:
A chipping simulation method, wherein identification display is performed for each estimated chipping damage magnitude. Shape acquisition means for acquiring vehicle outer shape data;
A trajectory calculating means for calculating a relative flight trajectory as seen from the running vehicle, within a predetermined range, which is a trajectory drawn by the virtual particles bounced up by the tire of the vehicle;
A chipping estimation means for calculating an intersection position between the relative flight trajectory and the outer shape data, and estimating a chipping occurrence position in a vehicle body;
A chipping simulation apparatus comprising: A vehicle design method for designing a vehicle using a computer,
On the computer,
A shape acquisition step for acquiring vehicle outer shape data;
A trajectory calculating step for calculating a relative flight trajectory as seen from the traveling vehicle, which is a trajectory drawn by the virtual particles bounced up by the tire of the vehicle, and
Calculating a crossing position between the relative flight trajectory and the outer shape data, and estimating a chipping occurrence position in a vehicle body; and
Correcting the outer shape based on the estimated chipping occurrence position;
The vehicle design method characterized by performing .

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