JP2006232064A - Characteristic figure comparing/estimating method, and simulation model producing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a characteristic figure comparing/estimating method facilitating visual shape comparison/estimation, and a simulation model producing method capable of efficiently fixing the simulation model. <P>SOLUTION: Compared targets are a tire ground surface shape 1 actually existing and a tire ground surface 2 which can be obtained by the simulation of a computer. As a comparative premise, a shape related to the characteristic in the characteristic figure is made to be independent from a background of the characteristic figure. Then, in at least two characteristic figures, the contraction scales of the characteristic figures having independent shapes are made to match. Those are superimposed while putting a shape becoming a reference at the forefront as shown in Fig.(a). As shown in Fig.(b), the compared targets are superimposed in a different order from the Fig.(a). The Fig.(a) and the Fig.(b) are indicated in parallel, thereby estimating the compared targets. A quantitatively estimated result can be used for correcting the simulation model. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a characteristic diagram comparison evaluation method and a simulation model creation method. More specifically, the present invention relates to a feature diagram comparison evaluation method that facilitates visual confirmation and evaluation, and a comparison using the comparison evaluation method. The present invention relates to a simulation model creation method capable of identifying a simulation model that is one of objects.

  Conventionally, when comparing and examining a shape in which a feature of a certain component is expressed and a shape similar to the shape, evaluation has been made by numerical values serving as a reference for the shape or simple visual comparison. For example, if one of the components to be compared is the actual ground contact shape of a tire and the other is a simulation result created by a computer, how much they match is the circumferential direction of the contact shape. It was evaluated and judged by operations such as measuring the length and seeing the paper on which both were transferred. In addition, even when comparing on the computer screen, after projecting multiple images to be compared, each is translucent, simply superimposed, or evaluated and judged by reference numerical values and visual observation, No special contrivance was made for the comparative evaluation work.

  However, in the comparative evaluation work as described above, it is not easy to quickly compare the shapes over the details and evaluate without individual differences.

  Therefore, the present invention has been made in view of the above, and a comparative evaluation method of a feature diagram that facilitates shape comparison evaluation by two or more objects, and one of comparison objects using the comparative evaluation method An object of the present invention is to provide a simulation model creation method capable of efficiently identifying a certain simulation model.

  In order to solve the above-described problems and achieve the object, the feature map comparison and evaluation method according to claim 1 is characterized in that the feature diagram in the feature diagram in which the feature of the structure to be compared is represented. A shape independence step that is independent from the background of the above, a scale identification step that matches the scales of the independent shapes of at least two or more of the feature diagrams, a first superposition step that overlaps the shapes, and A second superimposing step of superimposing the comparison objects in an order different from the first superimposing step, and a parallel display step of displaying the results of the first superimposing step and the second superimposing step side by side. It is a thing.

In the shape independence process, the shape that is characteristic in the subsequent process is superimposed, so that the background and shape of the figure are separated and independent, or only the shape is made independent independently by making it transparent, etc. It is a process of processing. In this way, when a plurality of shapes are overlaid and compared, it can be confirmed that if the shape overlaid is larger than the shape overlying, it will protrude. In the scale equalization process, it is preferable to enlarge / reduce the shape while maintaining the aspect ratio of the tire characteristic diagram constant.
In the first and second superimposing steps, it is preferable to superimpose a portion serving as a base point of the tire characteristic diagram. The parallel display may be displayed side by side with the left and right or top and bottom positions aligned. In this way, the difference of the comparison object becomes clear at a glance, and there is no individual difference in the evaluation.

  Further, the feature map comparison and evaluation method according to claim 2 is a shape independence step in which the shape related to the feature in the feature diagram expressing the feature of the structure to be compared is independent from the background of the feature diagram. And a scale identification process for matching the scales of the independent shapes of at least two or more feature diagrams, a first superposition process for superimposing the shapes, and a comparison target in a different order from the first superposition process. A plurality of reference lines that are common to both the figure superimposed in the first superimposing process and the figure superimposed in the second superimposing process. Evaluate the match of comparison objects using the difference distribution, summation, or least squares method

  In the present invention, it is possible to provide a reference line that is common to the comparison target and quantitatively evaluate how much the reference line is different.

  According to a third aspect of the invention, in the comparative evaluation method for the characteristic diagram, the characteristic diagram is a diagram in which a physical quantity accompanied by a shape is expressed in a structure to be compared.

  By comparing and displaying physical quantities having shapes, it is possible to easily compare and confirm differences between shapes to be compared. For example, when a vehicle tire is used as a structure to be compared, examples of the physical quantity include a tire contact shape, inflation profile, contact pressure distribution, friction energy distribution, or contact shear stress distribution. These all express the physical quantity that is the characteristic of the tire as a shape, and the characteristic can be examined by comparing these.

  According to a fourth aspect of the present invention, in the comparative evaluation method for the characteristic diagram, the characteristic diagram is a diagram representing a shape of a vehicle tire or a physical quantity related to the vehicle tire.

  According to the comparative evaluation method for characteristic diagrams according to the present invention, it is particularly effective when the characteristic diagram to be evaluated is a shape of the vehicle tire or a physical quantity related to the vehicle tire. This is because tires have physical properties with shape and distribution that have a great influence on the tire characteristics, so it is possible to display in parallel the figures with different superposition orders, and to clearly identify which figure is larger than which figure. In addition, it is beneficial to be able to easily distinguish and evaluate good and bad.

  In addition, even when the physical quantity is related to the tire, such as the tire ground contact shape, inflation profile, contact pressure distribution, friction energy distribution, or contact shear stress distribution, a graph with the overlapping order changed is displayed in parallel, and further on the reference line. This comparative evaluation method that evaluates the difference in the above by a statistical method is effective.

  According to a fifth aspect of the present invention, in the comparative evaluation method of the characteristic diagram, in the scale equalization step, the width of the land portion of the vertical groove or the width of the groove portion coincides with the aspect ratio of the shape being fixed. The scales are adjusted so as to match.

  This is a scale adjustment method that takes advantage of the characteristics of the tire and simplifies the adjustment when superimposing. For example, if the land width and the groove width of the groove of the comparison object are matched, the scales are naturally matched.

  Further, in the invention according to claim 6, in the comparison and evaluation method of the feature diagram, the scale equalization step matches straight lines passing through the centers of the shapes in the plurality of feature diagrams, and the aspect ratio is fixed. The scale is adjusted so that the lengths in the width direction match, and the scales of the shapes to be compared are matched.

  This is an effective adjustment method when comparing the case where the groove positions do not match or the shapes not including the groove.

  According to a seventh aspect of the present invention, in the comparison and evaluation method for the characteristic diagram, at least one of the comparison targets is a result of numerical analysis.

  It is useful for verifying the accuracy of the tire FE model by comparing and evaluating the actual measurement result and the numerical analysis result of the tire.

  Further, the invention according to claim 8 is to change one or more parameters that affect the shape of the tire numerical simulation model from the difference in physical quantity obtained by the comparison of the methods according to claims 1 to 7, A numerical simulation model is modified, and a simulation model with high accuracy is created by repeatedly performing the simulation until the difference between the simulation result and the actual measurement result within the reference value is within the reference value.

  By feeding back the difference between the actual measurement result and the numerical simulation result to the simulation model, it is possible to obtain a tire FE model that further embodies the analysis result. If a tread gauge, a tread radius, or the like is changed as a shape parameter, a more practical model can be obtained. Examples of material properties that affect the shape include elastic modulus, Poisson's ratio, density, and the like. By changing these, a practical model can be obtained. Material initial conditions that affect the shape include tension distribution, stress distribution, or strain distribution of the reinforcing cord.

  In the invention according to claim 9, in the simulation model creation method, the parameter is a parameter defining a geometric shape.

  When the measured shape and the simulation shape are compared and evaluated, if the simulation result greatly deviates from the measured shape, the shape parameter that is the basis of the simulation is changed. If the simulation shape obtained as a result is compared with the actually measured shape again, the simulation model will coincide with the actually measured shape as the operation is repeated several times. According to the characteristic evaluation method of the first to seventh aspects, the difference can be clearly and objectively determined, and can be used quantitatively to correct the simulation model.

  According to the method for comparing and evaluating feature diagrams according to the present invention, the comparison and evaluation of the shape in the feature diagram in which the features of the comparison object are expressed can be quickly and easily performed in detail. Further, according to the simulation model creation method of the present invention, it is possible to efficiently identify a simulation model that is one of the comparison targets using the comparative evaluation method.

  Embodiments of a comparative evaluation method for characteristic diagrams and a simulation model creation method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

  FIG. 1-1 is an external view showing an example in which vehicle tires are compared as an example of a structure to be compared. This example is a comparison of tire ground contact surface shapes (characteristic diagrams) in which important characteristics of vehicle tires appear. The two comparison objects are the actual ground contact surface shape 1 of the tire and the tire ground contact surface shape 2 obtained by computer simulation. Note that the number of comparison targets is not limited to two, and a plurality of comparison targets may be used.

  First, as a premise for comparison, the shape related to the feature in the feature diagram is made independent from the background of the feature diagram (shape independence step). In other words, the shape independence process superimposes the shape that is characteristic in the subsequent process, so the background and shape of the figure are separated and independent, or only the shape is made independent so that it passes through the background. Process such as putting it on. Specifically, if one of the comparison targets is a photographic image such as a tire contact surface that actually exists, only the shape is cut out from the background portion. This is the same as the contour cutting operation in the so-called photo retouching software of the computer.

  If one of the comparison targets is a simulation result by a computer, only the shape is made independent from the background coordinates and the colored background. Since the simulation result is an image of data according to the resolution, it is possible to image only the shape originally, but if there is a background such as coordinates, remove the background or place it in the background part The shape may be made substantially independent so as to have a property (transmittance) to transmit the figure superimposed below. In this case, the closer the transmittance of the background portion is to 100%, the more effective.

  Next, in at least two or more characteristic diagrams, the scales of the independent shapes as described above are matched (scale equalization step). FIG. 4 and FIG. 5 explain this process. There are various methods for making the scales identical. When there is a portion that can serve as a reference point between the shapes to be compared, the scales are matched to match the reference points. For example, as shown in FIG. 5, when the comparison target is the shape of the ground contact surface of the tire, the width of the land portion of the vertical groove or the width of the groove portion is adjusted to be the same while the aspect ratio of the original shape is fixed. Thus, the scales should be matched.

  Specifically, when the groove width of the actual tire contact surface shape is b, d, f, h, and the groove width in the simulation result to be compared is B, D, F, H, B / The scales are matched so that the magnitudes of b, D / d, F / f, and H / h match. Further, similarly to the groove width, the scales may be matched so that the sizes of A / a, C / c, E / e, G / g, and I / i coincide with the width of the land portion. When the above B / b, A / a, etc. are not uniform, the scale may be adjusted so that all average values are the same. The land portion of the groove is a relatively convex portion formed between the grooves provided in the circumferential direction of the tire.

  As another method, as shown in FIG. 4, the straight lines passing through the centers of the shapes in the plurality of feature diagrams are matched, and the lengths A and a in the width direction are matched while the aspect ratio is fixed. In this way, the scale is adjusted so that the scales of the shapes to be compared match. In the figure, a case where A is reduced so as to be a is shown.

  The former method in the above is a scale adjustment method that takes advantage of the characteristics of a vehicle tire and simplifies adjustment when superimposing. The latter is applicable to various comparison targets. The latter may be applied to the comparison of the shape of a vehicle tire, in particular, a plurality of vehicle tires in which tire grooves do not match or do not include grooves.

  Returning to FIG. 1-1, in the present invention, the shapes to be compared are made independent and the same scale is overlapped with the reference shape as the front as shown in FIG. One superimposing step). Further, as shown in FIG. 5B, the comparison objects are stacked in a different order from the first overlapping process (second overlapping process). And the result of a 1st superimposition process and a 2nd superimposition process is displayed side by side as shown in the figure (parallel display process), and a comparison target object is evaluated. In the first and second superimposing steps, it is preferable to superimpose a portion serving as a base point of the tire characteristic diagram, for example, a tire width limit line and a groove. In the parallel display, visual confirmation is easier when the left and right or upper and lower positions are aligned and displayed side by side on a computer monitor or the like.

  In this way, when a plurality of shapes are overlaid and compared, it can be confirmed that if the shape overlaid below is larger than the shape overlying, it protrudes. In FIG. 5A, the ground contact surface shape 1 of the tire that is actually present is displayed in the forefront, and the ground contact surface shape 2 obtained by the simulation is superimposed on the bottom, but there is no protruding portion. On the other hand, in FIG. 5B, the contact surface shape 2 obtained by the simulation is displayed in the forefront, and the portion 3 that protrudes from the contact surface shape 1 of the actually existing tire is displayed.

  If the comparison targets are superimposed and displayed as described above, it is obvious that the ground contact surface shape 2 obtained by the simulation is calculated to be short in the circumferential direction even though the scale is the same with reference to the groove or the like. . In addition, there is an advantage that a difference in recognition due to individual differences is less likely to occur. It is preferable to color-code the comparison target because the difference in size becomes clearer. When a human compares through a paper on which both figures are drawn, both figures show through, making comparison difficult. It can be said that the present invention is greatly different from this.

  FIG. 1-2 shows the same ground contact surface shape 1 of the actual tire of FIG. 1-1, and displays different simulation results 5 in accordance with the above method. Looking at both superposition results, unlike the case of FIG. 1-1, there is almost no portion where the ground contact surface shape 1 of the tire that actually exists under the simulation result 5 protrudes. Thereby, it can be seen instantly that the simulation result 5 is able to accurately simulate the actual contact surface shape.

  The characteristic diagram in the present invention needs to be a diagram in which a physical quantity accompanied by a shape appears in a structure to be compared. This is because the invention makes the difference in shape obvious. For example, when a vehicle tire is a structure to be compared, examples of the physical quantity accompanying the shape include a tire ground contact shape, an inflation profile, a contact pressure distribution, a friction energy distribution, or a contact shear stress distribution. By comparing these, tire characteristics can be evaluated and examined.

  In order for the computer to make the present invention, it is convenient to store the shape-independent items for each comparison target. Then, an object to be compared and evaluated is selected from the stock, a superposition method is selected, and superposed images are arranged at different positions in a designated position. Also, instead of saving the shape independence, it is the photos and simulation data that will be saved until you get bored, and when you select the comparison target, the shape independence process, the scale equalization process, multiple You may program so that the superimposition process of a time and a parallel display process may be performed.

  If it does as mentioned above, comparative evaluation will be possible at a glance, but, furthermore, when it is desired to evaluate the difference in the shape of the comparison object to some extent quantitatively, the figure superimposed in the first superimposing step and the second In the drawings superimposed in the superimposing step, a plurality of reference lines can be provided, and the degree of coincidence of the comparison object can be evaluated using a distribution of differences on the reference lines, a sum or a least square method.

  FIG. 2 is an explanatory diagram showing a diagram in which a plurality of reference lines are provided in the diagram superimposed in the first superimposing step and the diagram superimposed in the second superimposing step. In this figure, since the characteristic diagram relates to the shape of the tire contact surface, three reference lines, the tire center line 14 and the two tire width limit lines 13 and 15, which are important references for tire evaluation, are superimposed on each other (a ) (B).

  The specific evaluation method is as follows. In FIG. 5A, the difference between the actual ground plane shape 11 on the reference line 13 and the simulation result 12 is A1, the difference on the reference line 14 is A2, and the difference on the reference line 15 is A3. In FIG. 5B, the difference at the reference line 13 is B1, the difference at the reference line 14 is B2, and the difference at the reference line 15 is B3, and the difference between them is quantified by the value of ΣAi + ΣBi (i = 1, 2, 3). Can be evaluated.

Each value may be regarded as a distribution without obtaining the sum, and may be evaluated as a graph. Further, i = 1, 2, 3, Am, and Bm are average values, and n is the number of reference lines. (1 / n) * Σ (Ai−Am) ² + (1 / n) * Σ (Bi− Bm) ² may be obtained and the difference in shape as a whole may be evaluated. In this case, the smaller the numerical value, the more the comparison objects match.

  As a specific example for obtaining the above difference, as shown in FIG. 3, for example, the length of the contact surface of the actual tire 11 on the reference line 14 is L, and the length that the simulation result 12 protrudes when superimposed is ΔL. In this case, ΔL / L is one method. In some cases, only ΔL may be evaluated as a difference.

  According to the comparative evaluation method for characteristic diagrams according to the present invention, it is particularly effective when the characteristic diagram to be evaluated is a shape of the vehicle tire or a physical quantity related to the vehicle tire. This is because tires have physical properties with shape and distribution that have a great influence on the tire characteristics, so it is possible to display in parallel the charts with different superposition orders, and to clarify which figure is larger or smaller. In addition, it is extremely useful to be able to easily distinguish and evaluate good and bad.

  In addition, when the comparison target is a physical quantity related to the tire, such as the tire ground contact shape, inflation profile, contact pressure distribution, friction energy distribution, or contact shear stress distribution, the graphs with the overlapping order changed are displayed in parallel. In addition, this comparative evaluation method for evaluating the difference on the reference line by a statistical method is effective.

  The method for comparing and evaluating feature diagrams according to the present invention is applied to correction of a simulation model when one of the comparison objects is a feature diagram of an actual tire and the other is a feature diagram of the same type as a calculation result by a simulation model. Can do. Specifically, the shape parameter of the model of the numerical simulation is changed from the result of the difference in physical quantity obtained by the comparative evaluation method of the characteristic diagram, and the process is repeated until the difference between the two diagrams is within the reference value.

  FIG. 6A is an explanatory diagram illustrating a result of superimposing a simulation result on the front surface of the actual tire contact surface. FIG. 6B is an explanatory diagram illustrating a result of superimposing the actual ground contact surface shape on the simulation result in the forefront. Of the three reference lines 1, 2, and 3 provided in FIG. 6A, it is assumed that there is a protrusion of size 1 only at the reference line 2 at the center. Therefore, in the quantitative evaluation as described above, A1 = 0, A2 = 1, and A3 = 0.

  On the other hand, it is assumed that, out of the three reference lines 1, 2, and 3 provided in FIG. Therefore, in the quantitative evaluation as described above, B1 = 2, B2 = 0, and B3 = 0. The sum of the amount of protrusion is ΣAi + ΣBi = 3. To correct the parameters of the simulation model, the ratio of the amount of protrusion to the sum is used. The ratio of the amount of overhang and the sum total was used as the parameter change criterion because the influence of the parameter change on the calculation result is large, so it is preferable to change the parameter with a relative ratio that is a relatively small value. .

  In this way, the amount of change does not become too large, the overall shape does not change significantly, and an appropriate amount of deformation can be achieved. Specifically, as shown in FIG. 6-3, the reference line 1 portion of the simulation model is set to be 2/3 larger, and the reference line 2 portion is smaller to 1/3. Set. The portion of the reference line 3 is maintained as it is.

  If the new simulation shape obtained as a result of the above is compared with the actually measured shape again, the simulation model will coincide with the actually measured shape as the operation is repeated several times. According to the comparative evaluation method of the characteristic diagram of the present invention, the difference can be clearly and objectively determined, and can be used quantitatively to correct the simulation model.

  That is, by feeding back the difference between the actual measurement result and the numerical simulation result, the analysis result can be more embodied and the tire FE model can be obtained. The parameters of the simulation model may be related to a shape such as a tread gauge or a tread radius, or may be material characteristics such as rubber elastic modulus, Poisson's ratio, density, and the like. In the case of the initial material conditions, the tension distribution, stress distribution, strain distribution, or the like of the reinforcing cord may be changed as a parameter.

  FIGS. 7-1 and FIGS. 7-2 are explanatory drawings showing the result of comparing the result of correcting the simulation model by the above method with the actual tire profile. FIG. 7-1 compares the simulation result 20 before correction and the actual tire profile 21. In the figure, the simulation result 20 is deviated from the actual tire profile 21. On the other hand, when the shape parameter of the numerical simulation model is changed from the difference in the characteristic diagram as described above and the difference between the two diagrams is repeated within the reference value, the surface shape is changed as shown in FIG. 7-2. It came to match.

  In the figure, the groove bottom shapes are not yet matched, but this is affected by the measurement stylus when measuring the actual tire profile, and is not a problem because it is not important when evaluating the tire. . Note that the closer the simulated tire profile is to the actual tire profile, the closer the result of simulating the contact surface shape of the tire, the closer to the actual tire contact surface shape, as long as the material characteristics and the like are appropriate.

  As described above, the comparative evaluation method and the simulation model creation method of the characteristic diagram according to the present invention are useful when comparing the evaluation of the characteristic diagram whose shape is expressed as a feature and feeding back the comparison result to the simulation model, It is particularly suitable for evaluation, design and production of vehicle tires.

It is an external view which shows the example which compared the tire for vehicles. It is an external view which shows the example compared with FIGS. 1-1. It is explanatory drawing which shows the reference line of a superimposition figure. It is explanatory drawing which shows the example of evaluation of a difference. It is explanatory drawing which shows the method of making the scale of a tire the same. It is explanatory drawing which shows the method of making the scale of a tire the same. It is explanatory drawing which shows the result superimposed on the simulation result in the forefront of the actual tire contact surface shape. It is explanatory drawing which shows the result superimposed on the contact surface shape of the actual tire before the simulation result. It is explanatory drawing which shows a change when a simulation result is corrected. It is explanatory drawing which shows the result of having compared the simulation result before correction, and an actual tire profile. It is explanatory drawing which shows the result of having compared the simulation result after correction, and an actual tire profile.

Explanation of symbols

1, 2 Contact surface shape 5, 12, 20 Simulation result 11 Tire 13 Tire width limit line 14 Tire center line 21 Tire profile

Claims (9)

A shape independence step for making the shape related to the feature in the feature diagram in which the feature of the structure to be compared appears independent of the background of the feature diagram;
A scale identification step for matching the scales of the independent shapes of at least two or more of the feature diagrams;
A first superimposing step of overlapping the shape;
A second superposition step of superposing the comparison objects in an order different from the first superposition step;
A parallel display step of displaying the results of the first superposition step and the second superposition step side by side;
A comparative evaluation method of a feature diagram, characterized by comprising: A shape independence step for making the shape related to the feature in the feature diagram in which the feature of the structure to be compared appears independent of the background of the feature diagram;
A scale identification step for matching the scales of the independent shapes of at least two or more of the feature diagrams;
A first superimposing step of overlapping the shape;
A second superposition step of superposing the comparison objects in an order different from the first superposition step;
Have
By providing a plurality of reference lines that are common to the figure superimposed in the first superimposing process and the figure superimposed in the second superimposing process, using the distribution of the difference on the reference line, the sum or the least square method, A method for comparing and evaluating feature diagrams, wherein the degree of coincidence of comparison objects is evaluated.   The method for comparing and evaluating a feature diagram according to claim 1 or 2, wherein the feature diagram is a diagram in which a physical quantity accompanied by a shape appears in a structure to be compared.   The said characteristic figure is the figure which expressed the physical quantity regarding the shape of the tire for vehicles, or the tire for vehicles, The comparative evaluation method of the characteristic figure as described in any one of Claims 1-3 characterized by the above-mentioned.   The scale equalization step is performed by adjusting the width of the land portion of the vertical groove or the width of the groove portion to be the same while keeping the aspect ratio of the shape fixed. The comparative evaluation method of the characteristic figure as described in any one of -4.   In the scale equalization step, the straight lines passing through the centers of the shapes in the plurality of feature diagrams are matched, the scales are adjusted so that the lengths in the width direction are matched while the aspect ratio is fixed, and the shapes to be compared 5. The method for comparing and evaluating feature diagrams according to claim 1, wherein the scales are matched.   The method for comparing and evaluating feature diagrams according to claim 1, wherein at least one of the comparison targets is a result of numerical analysis.   The numerical simulation model is modified by changing one or more parameters that affect the shape of the tire numerical simulation model from the difference in physical quantity obtained by the comparison of the methods according to claim 1, and the model A simulation model creation method, characterized in that a simulation model with high accuracy is created by repeatedly performing a difference between a simulation result and a measurement result within a reference value.   The simulation model creation method according to claim 8, wherein the parameter is a parameter that defines a geometric shape.

Images