Evaluation method regarding tactile sense of human skin or simulated skin

Abstract

To provide a technology that improves the accuracy of evaluation related to the tactile sense of a human skin or a simulated skin using a contactor.SOLUTION: An evaluation method is a method for performing evaluation regarding the tactile sense of a human skin or a simulated skin on the basis of information detected by a sensor as a contactor is brought into contact with the inspection surface of the human skin or the simulated skin and the operation to be evaluated is conducted. The evaluation method includes: a step for acquiring measurement information for each contactor having been measured in association with the operation to be evaluated that is conducted on the inspection surface using a first contactor and a second contactor mutually differing in one or more physical properties among a plurality of physical properties; and a step for generating evaluation information corresponding to the first and the second physical properties related to the tactile sense of the inspection surface on the basis of acquired measurement information for each contactor. With the first contactor, sensitivity to the first physical property is higher than sensitivity to the second physical property; with the second contactor, sensitivity to the first physical property is lower than sensitivity to the second physical property.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a technique for evaluating the tactile sensation of human skin or simulated skin. [Background technology]

[0002] The following Patent Document 1 discloses a method for evaluating human skin or cosmetics, which evaluates the condition of a target surface, which is human skin or a surface created to resemble human skin, based on vibration information detected by a vibration sensor when a contactor is brought into contact with and slid over the target surface. The following Patent Document 2 discloses a skin or agent evaluation device that includes a flexible contactor that mimics the flexibility of a human finger, a contact surface on the outer surface of the contactor that comes into contact with a subject, and a force sensor that is provided inside the contactor and measures the force received from the subject via the contact surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-095263 [Patent Document 2] Japanese Patent Publication No. 2022-161710 Summary of the Invention [Problem to be solved by the invention]

[0004] In sensory evaluation of tactile sensation using human fingers, palms, etc., it is difficult to perform objective quantitative evaluation because it is heavily dependent on the senses of the evaluator. However, the above-mentioned evaluation method and evaluation device use contacts that mimic the flexibility of human fingers, making it possible to perform evaluation related to the tactile sensation of the test surface easily and with high sensitivity.

[0005] The inventors discovered that the physical properties of the contactor have a significant impact on detecting physical characteristics of the test surface that can cause differences in the feel or tactile sensation of the test surface using a contactor, similar to the evaluation method described above, and further succeeded in identifying the physical properties of the contactor that make it easier to detect these characteristics. Based on this new knowledge, the present invention provides a technique that can improve the accuracy of evaluation related to the tactile sensation of human skin or simulated skin using a contact. [Means for solving the problem]

[0006] According to the present invention, there is provided a method for performing an evaluation related to the tactile sensation of human skin or simulated skin based on information detected by a sensor as an evaluation target action is performed by contacting a contactor simulating the flexibility of a human finger with a test surface of human skin or simulated skin that resembles human skin. The method includes: an acquisition step of acquiring measurement information for each contactor measured in association with the evaluation target action on the test surface using a first contactor and a second contactor that differ from each other in one or more physical properties among a plurality of physical properties that can cause differences in tactile sensation; and a generation step of generating evaluation information corresponding to a first physical property related to the tactile sensation of the test surface and a second physical property different from the first physical property, based on the acquired measurement information for each contactor; wherein the first contactor has a higher sensitivity to the first physical property than the sensitivity to the second physical property, and the second contactor has a lower sensitivity to the first physical property than the second physical property.

[0007] Furthermore, according to the present invention, there is provided an evaluation system that includes the contact and the sensor and is capable of executing the above-described evaluation method. Furthermore, according to the present invention, there is provided a program that can cause a computer to execute the above-described evaluation method, or a computer-readable storage medium that stores such a program. [Effects of the Invention]

[0008] According to the above aspect, it is possible to provide a technology that can improve the accuracy of evaluation related to the tactile sensation of human skin or simulated skin using a contact. [Brief explanation of the drawings]

[0009] [Figure 1] 1A and 1B are diagrams illustrating examples of contacts and sensors used in the evaluation method according to the present embodiment. [Figure 2] 1 is a flowchart showing an evaluation method according to the first embodiment (first evaluation method). [Figure 3] 10A and 10B are diagrams illustrating examples of evaluation information that can be compared between test surfaces. [Figure 4] 10 is a flowchart showing an evaluation method according to a second embodiment (second evaluation method). [Figure 5] 10 is a flowchart showing a method for manufacturing a contact set of a first contact and a second contact (the present manufacturing method). [Figure 6] FIG. 1 is a diagram conceptually illustrating an example of a hardware configuration of an evaluation system according to an embodiment of the present invention. [Figure 7] FIG. 7(a) is a table showing the characteristics of the six contacts used in this verification, and FIG. 7(b) is a table showing the characteristics of the seven artificial skin samples used in this verification. [Figure 8] Figure 8(a) is a graph showing the friction coefficients of simulated skin A, B, and C for each of the six contacts (fingers 1 to 6), and Figure 8(b) is a graph showing the vibration intensity of simulated skin A, B, and C for each of the six contacts (fingers 1 to 6). [Figure 9] This is a graph showing the coefficients of friction of simulated skin A, D, and E for each of six contacts (fingers 1 to 6). [Figure 10] This is a graph showing the coefficients of friction of simulated skin A, F, and G for each of the six contacts (fingers 1 to 6). [Figure 11] 10 is a graph plotting the vibration intensity and friction coefficient of seven simulated skin samples obtained using contact 3 on a two-axis coordinate system. [Figure 12] Figure 12(a) is a graph showing the friction coefficients of simulated skin A and E, which have the same surface roughness and hardness but different surface properties for contactor 6 and contactor 2, respectively. Figure 12(b) is a graph showing the friction coefficients of simulated skin A and F, which have the same surface roughness and surface properties but different hardness for contactor 6 and contactor 2, respectively. [Figure 13] Figure 13(a) is a graph showing the friction coefficients of simulated skin G and E, which have the same surface roughness but different surface textures and hardness for contactor 6 and contactor 2, respectively, and Figure 13(b) is a graph showing the friction coefficients of simulated skin F and E, which have the same surface roughness but different surface textures and hardness for contactor 6 and contactor 2, respectively. [Figure 14] Figure 14(a) is a graph plotting the friction coefficients of contactor 6 and contactor 2 for each of the simulated skins A, D, E, F, and G, which have the same surface roughness, on a two-axis coordinate system, and Figure 14(b) is a graph plotting the friction coefficients of contactor 6 and contactor 2 for each of the simulated skins A to G, on a two-axis coordinate system. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments of the present invention will be described below. Note that the following embodiments are merely examples, and the present invention is not limited to the configurations of the following embodiments.

[0011] First, an overview of the evaluation method according to this embodiment (hereinafter referred to as the present evaluation method) will be given. This evaluation method involves bringing a contactor that mimics the flexibility of a human finger into contact with the test surface of human skin or a simulated skin that mimics human skin, and performing the action to be evaluated, and then evaluating the tactile sensation of the human skin or the simulated skin that mimics human skin based on information detected by a sensor. Hereinafter, unless it is necessary to distinguish between human skin and simulated skin, human skin and simulated skin may be abbreviated to simply skin.

[0012] The human skin targeted by this evaluation method may be any human skin, including not only facial skin but also skin on other body parts (neck, hands, arms, legs, back, etc.) and skin on the lips. The artificial skin targeted by this evaluation method is not limited in any way as long as it is formed so that a tactile sensation can be obtained from the artificial skin itself or from the cosmetic applied to the artificial skin, and there are no limitations on its surface shape, physical properties, material, etc. The evaluation targets of this evaluation method include human skin itself and simulated skin itself, as well as cosmetics applied to human skin or simulated skin and cosmetic treatments applied to human skin. Cosmetics to be evaluated include, but are not limited to, skin care cosmetics such as lotions, emulsions, creams, serums, packs, lip balms, eye care sheets, mouth sheets, pack masks, sheet lotions, and sheet makeup removers; cleansers such as soaps, cleansers, and makeup removers; foundations, makeup bases, liquid foundations, oil-based foundations, powder foundations, concealers, control colors, eye shadows, blushers, lipsticks, lip glosses, lip liners, and makeup cosmetics for the body and décolleté; and UV protection cosmetics such as sunscreen emulsions, sunscreen gels, and sunscreen creams.

[0013] Furthermore, in the evaluation related to the feel of the skin using this evaluation method, only the feel may be evaluated, or the physical properties or surface shape that may cause differences in the feel may be evaluated, or a combination of these may be evaluated. The evaluation of tactile sensation includes, for example, frictional sensation, roughness, hardness, elasticity, stickiness, oiliness, moistness, refreshing feeling, dryness (dryness), stiffness, roughness, smoothness, softness, smoothness, firmness, sliminess, stickiness, silkiness, moisture, oiliness, adhesion, richness, skin compatibility, sticky feeling, springy feeling, penetration feeling, squeaky feeling, etc. However, tactile sensations that can be evaluated are not limited to these examples, and any index of sensation felt when touched may be evaluated. "Frictional feeling" refers to the resistance felt by friction from the surface when the contact surface of a finger or a contactor is brought into contact with the test surface and slid over it; "Smooth feeling" refers to the smoothness or roughness of the test surface felt by sliding in the same way as frictional feeling; "Hardness feeling" refers to the degree of deformation of the skin felt when the contact surface is brought into contact with the test surface; "Elasticity feeling" refers to the degree of rebound felt when the contact surface is brought into contact with the test surface; "Stickiness feeling" refers to the degree of stickiness felt when the contact surface is brought into contact with the test surface; "Oily feeling" and "Greasy feeling" refer to the degree of greasiness felt when the contact surface is brought into contact with the test surface; and "Moist feeling" refers to the degree of skin deformation felt when the contact surface is brought into contact with the test surface. It indicates the degree of slightly moist smoothness felt when the contact surface is brought into contact with the test surface. "Refreshing feeling" indicates the smooth and refreshing feeling felt when the contact surface is brought into contact with the test surface. "Dry (dry) feeling" indicates the degree of dryness felt when the contact surface is brought into contact with the test surface. "Rough feeling" indicates the rough feeling of the test surface surface felt by sliding in the same way as friction. "Rough feeling" indicates the rough feeling of the test surface surface felt by sliding in the same way as friction. "Smooth feeling" indicates the feeling that the contact surface moves smoothly in the same way as friction. "Soft feeling" indicates the degree of smoothness felt by sliding in the same way as friction. It indicates the degree of softness felt when the contact surface is brought into contact with the test surface. "Smoothness" indicates the degree of smoothness felt by sliding, similar to the feeling of friction. "Firmness" indicates the feeling of the test surface bouncing back when the contact surface is brought into contact with the test surface. "Slippery" indicates the slippery feeling felt when the contact surface is brought into contact with the test surface. "Sticky" indicates the feeling of the contact surface adhering to the test surface when the contact surface is brought into contact with the test surface. "Dry" indicates the degree of slipperiness felt by sliding, similar to the feeling of friction. "Freshness" indicates the degree of slipperiness felt when the contact surface is brought into contact with the test surface. It indicates the degree of wetness felt when touched, "adhesion" indicates the feeling of the cosmetic adhering to the skin when applied to the skin, "richness" indicates the feeling of the cosmetic spreading and feeling heavy when applied to the skin, "skin compatibility" indicates the feeling of the cosmetic fitting into the skin when applied to the skin, "stickiness" indicates the feeling of softness and adhesion when the contact surface is brought into contact with the test surface, "softness" indicates the feeling of slight adhesion but bouncing back when the contact surface is brought into contact with the test surface, and "penetration" indicates the feeling of the cosmetic penetrating into the skin when applied to the skin."Squeaking" refers to the creaking sensation of the test surface that is felt due to sliding, similar to the sensation of friction.

[0014] "Physical properties" are indices that represent the physical properties of a substance such as skin or a contact that has a test surface. In this embodiment, the "physical properties that can cause a difference in the tactile sensation" include, for example, indexes that represent properties against externally applied force, such as smoothness, adhesiveness, hardness (rigidity), etc. In this case, "smoothness" or "adhesiveness" can also be expressed as "surface texture." Furthermore, the "surface shape that can create a difference in the tactile sensation" in this embodiment includes the size of the surface irregularities, the surface roughness, and the like.

[0015] The contactors used in this evaluation method are not limited in structure or material as long as they have flexibility that mimics the flexibility of human fingers. Furthermore, the sensors used in this evaluation method are not limited in any way as long as they can detect the force and vibration that are mechanically generated when the contactors are brought into contact with the test surface of the skin and the target action is performed, and there are no limitations on the installation position, specific detection principle, configuration, etc.

[0016] Figure 1 shows an example of a contact and a sensor used in the evaluation method according to this embodiment. Figure 1(a) shows the appearance of a contact 100 worn on a human finger, and Figure 1(b) shows a schematic cross section of the contact 100 worn on a human finger. 1 has a shape that can be worn on a human finger, and is formed to have flexibility that mimics the flexibility of a human finger. Mimicking the flexibility of a human finger means having flexibility that is close to the characteristics of a human finger, such as softness and hardness, and this is achieved by forming the contact 100 from an elastomer such as soft rubber or gel, for example.

[0017] 1 has a laminated structure in which an upper layer 10, an intermediate layer 20, and a lower layer 30 are laminated. The upper layer 10 includes a contact surface that comes into contact with the test surface of the skin, the intermediate layer 20 is provided on the opposite side of the contact surface of the upper layer 10, and the lower layer 30 is provided more inward than the intermediate layer 20. However, the contact 100 is not limited to the laminated structure shown in the example of FIG. 1, and may have a two-layer structure or a structure of four or more layers, or may have a single-layer structure as long as it includes a contact surface that comes into contact with the test surface of the skin. For example, in order to make the characteristics such as softness and hardness closer to those of a human finger, the upper layer 10 is formed of silicone and the middle layer 20 is formed of urethane gel. The lower layer 30 is formed of ASA resin. However, the material of the contact 100 is not limited to this example. The upper layer 10 and the middle layer 20 may be formed of the same material, for example, urethane gel. Furthermore, in order to achieve various softness or hardness, multiple upper layer parts 10 and multiple middle layer parts 20 with different flexibilities may be configured to be detachable from the lower layer 30. The contact surface of the upper layer 10 has a surface shape that mimics the surface shape of a human finger. For example, grooves that mimic fingerprints are formed on the contact surface of the upper layer 10. However, the grooves may have any shape other than elliptical, such as spiral or linear. Furthermore, the contact surface may have a flat surface shape without grooves, depending on the specimen to be evaluated.

[0018] 1, the force sensor 40 and the vibration sensor 50 are provided on the contactor 100. The force sensor 40 is provided inside the lower layer 30 of the contactor 100, and the vibration sensor 50 is provided by being wrapped around the contactor 100. However, the arrangement of the force sensor 40 and the vibration sensor 50 is not limited to the example in FIG. 1, and for example, the vibration sensor 50 does not have to be provided on the contactor 100. The force sensor 40 is, for example, a multi-axis sensor. However, the force sensor 40 is not limited to this example and may be a sensor using a strain gauge, capacitance, pressure-sensitive conductivity, piezoelectric effect, piezoresistive effect, light, acoustics, a magnetic field, contact resistance, or the like. The vibration sensor 50 is not limited to a specific configuration as long as it can measure vibrations occurring on the contact surface. The vibration sensor 50 can be realized by, for example, a piezoelectric element, a strain gauge, an acceleration sensor, or the like.

[0019] 1 has the same configuration as the contactor disclosed in the above-mentioned Patent Document 2. However, the contactor and sensor used in this evaluation method are not limited to the example in FIG.

[0020] The actions to be evaluated using such contactors can be any actions that can obtain the feel of skin or the surface shape and physical properties that create the feel, such as sliding, twisting, pushing, touching and lifting, and pushing and lifting.

[0021] As described above, the inventors have succeeded in identifying the physical properties of a contact that can easily detect the texture of the test surface or the physical property features of the test surface that can cause differences in the texture. Based on this new knowledge, the present evaluation method uses at least a first contactor and a second contactor that differ from each other in one or more physical properties among a plurality of physical properties that can cause a difference in tactile sensation. For example, a first contactor and a second contactor that differ from each other in at least surface texture are used. As another example, a first contactor and a second contactor that differ from each other in surface texture and hardness are used. Naturally, a first contactor and a second contactor that differ from each other not only in surface texture and hardness but also in surface shape (surface unevenness) may also be used. The first contactor and the second contactor may each be used one by one, or multiple of each, or multiple of one and one of the other. That is, in this evaluation method, multiple contactors including at least one or more first contactors and one or more second contactors are used.

[0022] As specific examples of such an evaluation method, evaluation methods according to the first and second embodiments will be described below.

[0023] [First embodiment] FIG. 2 is a flowchart showing the evaluation method according to the first embodiment (hereinafter, sometimes referred to as the first evaluation method). As shown in Figure 2, the first evaluation method includes a step (S21) of acquiring measurement information measured in association with an evaluation target action on a test surface using a first of the two contactors described above, a step (S22) of acquiring measurement information measured in association with an evaluation target action on a test surface using a second of the two contactors, and a step (S23) of generating evaluation information corresponding to a first physical property related to the tactile sensation of the test surface and a second physical property different from the first physical property based on the measurement information for each contactor acquired in steps (S21) and (S22).

[0024] According to the example of FIG. 1, in step (S21) and step (S22), friction information can be acquired from the force sensor 40 as the measurement information, and vibration information can be acquired from the vibration sensor 50 as the measurement information. The friction information is measurement information corresponding to the friction force generated when the motion to be evaluated is performed with the contactor in contact with the test surface. In the example of Fig. 1, the friction information is measurement information based on information detected by the force sensor 40 when the motion to be evaluated is performed with the contactor in contact with the test surface. If the force sensor 40 is a multi-axis sensor, the friction coefficient (Fx / Fz), which can be calculated from the horizontal force (Fx) and the vertical force (Fz) relative to the contact surface, can be acquired as the friction information. However, the acquired friction information is not limited to the friction coefficient alone, and may be information calculated by some method from either or both of Fx and Fz.

[0025] The vibration information is measurement information related to vibrations that occur when an evaluation target action is performed with the contactor in contact with the test surface. In the example of FIG. 1, the vibration information is measurement information based on information detected by the vibration sensor 50 when the evaluation target action is performed with the contactor in contact with the test surface. For example, vibration intensity is used as the vibration information. However, the acquired vibration information is not limited to vibration intensity alone, and may be vibration waveform data, vibration power spectrum data obtained by performing processing such as frequency analysis on such vibration waveform data, or feature amount data extracted from such vibration-related data.

[0026] The measurement information acquired in steps (S21) and (S22) may be friction information only, vibration information only, or both. That is, in step (S21), one or both of friction information and vibration information measured in association with the sliding operation of the first contactor on the test surface is acquired, and in step (S22), one or both of friction information and vibration information measured in association with the sliding operation of the second contactor on the test surface is acquired. The measurement information may be any information that can be detected by some kind of sensor when the operation to be evaluated is performed with the contactor in contact with the test surface, and is not limited to friction information or vibration information. For example, the measurement information may be force information (a force in the vertical direction, such as a pressing force on the test surface) that can be detected by the above-mentioned force sensor 40 or the like. The friction information and vibration information may also be acquired based on information detected by a sensor other than the force sensor 40 or the vibration sensor 50. For example, the friction information or vibration information may be acquired from sound generated by contact or from video information showing the vibration of the contactor or the test surface. Information or intensity values derived from friction obtained from the acquired vibration waveform may also be acquired as the friction information or vibration information. Information on the movement of the contactor at the time of contact (such as velocity, acceleration, angular velocity, and attitude information such as the inclination of the contactor) acquired by a motion sensor or video information may also be acquired as the friction information or vibration information. Hereinafter, the measurement information acquired in step (S21) may be referred to as measurement information of the first contactor, and the measurement information acquired in step (S22) may be referred to as measurement information of the second contactor.

[0027] In step (S23), evaluation information corresponding to a first physical property related to the tactile feel of the test surface and a second physical property different from the first physical property is generated. The first and second physical properties corresponding to the generated evaluation information are determined depending on the physical properties of the first and second contacts, i.e., the first and second physical properties are related such that the sensitivity of the first contactor to the first physical property is higher than the sensitivity of the second physical property, and the sensitivity of the second contactor to the first physical property is lower than the sensitivity of the second physical property. Here, "sensitivity to physical properties of a contactor" means the degree of change between test surfaces in the measurement information obtained by using a certain contactor to perform an evaluation operation on each test surface having different physical properties, and when the degree of change in the measurement information between test surfaces is large, the sensitivity is expressed as high, and when the degree of change is small, the sensitivity is expressed as low.

[0028] The inventors have newly discovered the existence of a physical property of a contactor whose sensitivity to a first physical property of a test surface and whose sensitivity to a second physical property of the test surface are mutually inverted, and have identified such a physical property of the contactor. For example, the magnitude of surface asperity, surface texture, and hardness have been identified as physical properties of a contactor whose sensitivity to the surface texture of a test surface and whose sensitivity to the hardness of the test surface are mutually inverted. As a result, by using a first contactor and a second contactor whose surface textures are different from each other, whose surface textures and hardnesses are both different from each other, or whose surface asperity and hardnesses are both different from each other, it is possible to generate evaluation information corresponding to both the surface texture (first physical property) and hardness (second physical property) of a test surface.

[0029] Therefore, since the sensitivity corresponding to the first contactor is higher for the first physical property than for the second physical property, evaluation information corresponding to the first physical property is generated based on the measurement information of the first contactor, and since the sensitivity corresponding to the second contactor is higher for the second physical property than for the first physical property, evaluation information corresponding to the second physical property is generated based on the measurement information of the second contactor. For example, when a first contactor and a second contactor having different surface properties are used, where the first contactor has a higher sensitivity to the surface property (first physical property) of the test surface than to hardness (second physical property), and the second contactor has a lower sensitivity to the surface property (first physical property) of the test surface than to hardness (second physical property), evaluation information corresponding to the surface property (first physical property) of the test surface is generated based on the measurement information of the first contactor, and evaluation information corresponding to the hardness (second physical property) of the test surface is generated based on the measurement information of the second contactor.

[0030] The evaluation information generated in step (S23) is evaluation information related to the feel of the test surface and may correspond to the first and second physical properties of the test surface, and the specific content thereof is not limited. For example, evaluation information (evaluation values) such as hardness, smoothness, stickiness, and moistness may be generated for each of the first and second physical properties, or evaluation information on the feel obtained comprehensively from the evaluation results of the first and second physical properties may be generated. Furthermore, the measurement information of a first contactor that is highly sensitive to a first physical property may be directly used as evaluation information corresponding to the first physical property, and the measurement information of a second contactor that is highly sensitive to a second physical property may be directly used as evaluation information corresponding to the second physical property. Examples of the evaluation information generated in step (S23) include the following:

[0031] In steps (S21) and (S22), when measurement information for each contact is acquired for each of multiple test surfaces, including one or both of one or more human skin test surfaces or one or more simulated skin test surfaces, evaluation information is generated in step (S23) so that the acquired measurement information for each contact can be compared between test surfaces. In this case, "multiple test surfaces" include multiple test surfaces of the same person with different skin conditions, multiple test surfaces of the same person in different locations, multiple test surfaces of the same person's skin at different times, multiple test surfaces of the same simulated skin with different conditions, multiple test surfaces of the skin of different people, and multiple test surfaces of different simulated skin. "Multiple test surfaces with different human skin or simulated skin conditions" may include, for example, a test surface of skin with a cosmetic applied and a test surface of skin without the cosmetic applied, test surfaces of skin with different cosmetic applied, test surfaces of skin with a specific cosmetic treatment and a test surface of skin without the treatment, and test surfaces of skin with different cosmetic treatments. Furthermore, a combination of skin with a lotion applied and skin with a milky lotion applied, or a combination of skin after skin care (skin with a skin care product applied) and skin after makeup (skin with a makeup product applied) also falls under "multiple test surfaces with different human skin or simulated skin conditions." However, the plurality of test surfaces are not limited as long as they are test surfaces for which it is desired to compare the evaluation of the tactile sensation with each other.

[0032] FIG. 3 is a diagram showing an example of evaluation information that can be compared between test surfaces. 3, the measurement information of the first contactor having a high sensitivity to the first physical property is directly used as evaluation information corresponding to the first physical property, and the measurement information of the second contactor having a high sensitivity to the second physical property is directly used as evaluation information corresponding to the second physical property. Since the measurement information of the first contactor and the second contactor for two people's human skin test surfaces 1 and 2 has been acquired, the measurement information when the first contactor is applied to test surface 1 and the measurement information when the first contactor is applied to test surface 2 are shown in horizontal bar graphs, and the measurement information when the second contactor is applied to test surface 1 and the measurement information when the second contactor is applied to test surface 2 are shown in horizontal bar graphs.

[0033] However, the evaluation information that can be compared between test surfaces is not limited to the bar graph exemplified in Fig. 3 and may be in various forms. For example, when the measurement information of the first contactor is directly used as evaluation information corresponding to the first physical property and the measurement information of the second contactor is directly used as evaluation information corresponding to the second physical property, a two-dimensional graph in which the measurement information of each test surface is plotted in a two-dimensional coordinate system in which the measurement information of the first contactor is the first axis and the measurement information of the second contactor is the second axis may be generated as evaluation information that can be compared between test surfaces.

[0034] Such measurement information makes it easy to compare the evaluation of the tactile sensation of the subject's skin with that of a comparison skin desired by the subject, for each of the first and second physical properties. The comparison skin desired by the subject may be, for example, the skin of a celebrity that the subject likes or a model skin that imitates such a celebrity, the skin that the subject considers ideal, or average skin for each age group. Furthermore, by comparing information between skin before and after the application of the target cosmetic product or target cosmetic treatment, or between skin to which different cosmetic products have been applied, it is possible to easily verify the effects of the target cosmetic product or target cosmetic treatment, and compare the effects of cosmetics.

[0035] In addition, in step (S23), evaluation information may be generated based at least on the difference between the measurement information of each test surface obtained using the first contact and the difference between the measurement information of each test surface obtained using the second contact. For example, a test surface (hereinafter referred to as a reference test surface) may be set as a reference for determining the difference in measurement information, and evaluation information may be generated based on the difference in measurement information from the reference test surface. For example, a standard skin test surface for each age group may be set as the reference test surface for each age group, and evaluation information indicating the skin age related to the tactile sensation of each test subject may be generated by identifying the age group in which the difference in measurement information between the skin test surface of each test subject and the reference test surface for each age group is smallest. Furthermore, evaluation information indicating a difference in a first physical property between test surfaces and a difference in a second physical property between test surfaces may be generated based on a combination of the presence or absence of a difference in the measurement information of each test surface obtained using the first contactor and the presence or absence of a difference in the measurement information of each test surface obtained using the second contactor. Furthermore, evaluation information indicating a classification related to the tactile sensation may be generated based on the difference in measurement information. In this way, by calculating the difference in the measurement information of each test surface for each contact and generating evaluation information based on this difference, it is possible to easily compare evaluations of the tactile sensation of the test surface.

[0036] [Second embodiment] FIG. 4 is a flowchart showing an evaluation method according to the second embodiment (hereinafter, sometimes referred to as a second evaluation method). As shown in Figure 4, the second evaluation method includes a step (S41) of acquiring measurement information measured in association with an evaluation target action on a test surface using a first contactor, a step (S42) of acquiring measurement information measured in association with an evaluation target action on a test surface using a second contactor, a step (S43) of acquiring measurement information measured in association with an evaluation target action on a test surface using a third contactor, a step (S44) of classifying the surface shape of the test surface based on the measurement information of the third contactor acquired in step (S43), and a step (S45) of generating evaluation information corresponding to first and second physical properties related to the tactile feel of the test surface based on the measurement information of the first and second contactors acquired in steps (S41) and (S42) and the surface shape classification results.

[0037] In addition to the above-mentioned findings, the inventors discovered that when evaluating physical properties related to the tactile sensation of a test surface, differences in the surface shape of the test surface reduce the accuracy of the evaluation of the physical properties, and deduced that differences in physical properties related to the tactile sensation can be evaluated with high accuracy if the test surfaces have similar surface shapes. Therefore, in the second evaluation method, as described above, the surface shape of the test surface is classified, and the classification results are then used to generate evaluation information corresponding to the first and second physical properties related to the tactile feel of the test surface. This makes it possible to prevent the accuracy of the evaluation corresponding to the first and second physical properties relating to the tactile feel of the test surface from being reduced due to the influence of the surface shape of the test surface.

[0038] Each step of the second evaluation method will be described in detail below. Step (S41) and step (S42) are the same as step (S21) and step (S22) in the first embodiment. Step (S43) is also similar to steps (S21) and (S22) except that the contacts used are different. The third contactor used in step (S43) may have one or more physical properties different from those of the first contactor and the second contactor, and may have a physical property or surface shape that increases sensitivity to the surface shape of the test surface. For example, as will be described later as an example, when the coefficient of friction is acquired as the measurement information, it is preferable to select a contactor with small surface irregularities as the third contactor, and when the vibration intensity is acquired as the measurement information, it is preferable to select a contactor with a slippery surface shape as the third contactor.

[0039] However, as will be described later as an example, since there may be a contactor whose sensitivity to the first physical property of the test surface and whose sensitivity to the second physical property of the test surface are mutually reversed and whose sensitivity to the surface shape of the test surface is high, it is also possible for the second evaluation method not to use the third contactor. In that case, step (S43) may be omitted, and in step (S44), the surface shape of the test surface may be classified based on the measurement information of the first contactor or the measurement information of the second contactor.

[0040] The inventors have also found that the surface shape of the test surface can be classified with high accuracy by using both friction information and vibration information as measurement information. Therefore, in step (S44), the surface shape of the test surface may be classified based on the friction information and vibration information as measurement information of the first contactor, the second contactor, or the third contactor. However, it is also possible to classify the surface shape of the test surface based only on the friction information or only on the vibration information. In the classification in step (S44), the surface shape group to which the surface shape of the test surface belongs is determined from two or more surface shape groups that are predetermined based on the degree of surface unevenness (large, medium, small), the degree of surface roughness (large, medium, small), etc.

[0041] In step (S45), evaluation information corresponding to the first and second physical properties relating to the tactile sensation of the test surface is generated based on the surface shape classification results. For example, a relational expression for obtaining evaluation information corresponding to the first and second physical properties from measurement information for each surface shape group by a population survey or the like is stored in advance, and evaluation information corresponding to the first and second physical properties relating to the tactile sensation of the test surface is generated using the relational expression corresponding to the surface shape group to which the surface shape of the test surface determined in step (S44) belongs. However, the method for generating evaluation information based on the surface shape classification results is not limited to this example.

[0042] The second evaluation method may further generate evaluation information regarding the surface shape of the test surface based on the measurement information of the third contactor acquired in step (S43). The generated evaluation information regarding the surface shape may indicate the degree of surface irregularity (large, medium, small), the degree of surface roughness (large, medium, small), etc. Furthermore, evaluation information may be generated that allows the measurement information of the third contactor to be compared between test surfaces. The measurement information used to generate evaluation information related to the surface shape may be friction information alone, vibration information alone, or both. In this way, not only evaluation information corresponding to the physical properties related to the feel of the test surface but also evaluation information corresponding to the surface shape can be obtained.

[0043] [Contact set manufacturing method] The contact set of the first contact and the second contact used in the first and second evaluation methods described above is prepared (manufactured) as follows. FIG. 5 is a flowchart showing a method for manufacturing a contact set of a first contact and a second contact (hereinafter, sometimes referred to as this manufacturing method). This manufacturing method includes a step (S51) of preparing a plurality of first simulated skins having a common second physical property but different first physical properties, a step (S52) of preparing a plurality of second simulated skins having a common first physical property but different second physical properties, and a step (S53) of preparing a plurality of contacts each having one or more different physical properties from among a plurality of physical properties that may cause a difference in tactile sensation. The first physical property and the second physical property correspond to the evaluation information generated by the above-described first and second evaluation methods. The plurality of first simulated skins and the plurality of second simulated skins preferably have common physical properties other than the first physical property and the second physical property, but may also be different.

[0044] This manufacturing method further includes a step (S54) of acquiring first measurement information by bringing each of the multiple contactors prepared in step (S53) into contact with the multiple first simulated skins prepared in step (S51) and performing the action to be evaluated, a step (S55) of acquiring second measurement information by bringing each of the multiple contactors prepared in step (S53) into contact with the multiple second simulated skins prepared in step (S52) and performing the action to be evaluated, and a step (S56) of selecting a first contactor and a second contactor from the multiple contactors.

[0045] In step (S54), first measurement information is acquired for each first simulated skin and each contact, and in step (S55), second measurement information is acquired for each second simulated skin and each contact. The methods for acquiring measurement information in steps (S54) and (S55) are the same as those in the first and second embodiments described above.

[0046] In step (S56), a first contact and a second contact are selected from the plurality of contacts based on the difference between the first measurement information for each first simulated skin and the difference between the second measurement information for each second simulated skin. Here, if there is a large difference (degree of change) between the first measurement information for each first simulated skin obtained using a certain contactor, it can be said that the contactor has a high sensitivity to the first physical property because the first simulated skins each have a different first physical property. Conversely, if there is a large difference (degree of change) between the second measurement information for each second simulated skin obtained using a certain contactor, it can be said that the contactor has a high sensitivity to the second physical property because the second simulated skins each have a different second physical property. On the other hand, if a certain contact has high sensitivity to both the first property and the second property, it is difficult to distinguish between the first property and the second property for that contact, especially if the contact has low sensitivity to both the first property and the second property. Therefore, in step (S56), based on the difference in the first measurement information for each first simulated skin and the difference in the second measurement information for each second simulated skin, a contactor having a higher sensitivity to the first physical property than the second physical property is selected as the first contactor, and a contactor having a higher sensitivity to the second physical property than the first physical property is selected as the second contactor. At this time, it is preferable that the contactor having the largest difference in sensitivity to both physical properties is selected. In step (S56), one or more first contacts and one or more second contacts may be selected.

[0047] According to this manufacturing method, it is possible to prepare (manufacture) a contact set in which the sensitivity to the first physical property and the sensitivity to the second physical property are mutually reversed, and by using the contact set prepared in this manner, it is possible to perform highly accurate evaluations corresponding to the first and second physical properties related to the tactile sensation of the test surface, as in each of the above-mentioned embodiments.

[0048] [Rating System] The evaluation method according to each of the above-described embodiments can be executed by an evaluation system 1 as shown in Fig. 6. Fig. 6 is a diagram conceptually showing an example of the hardware configuration of the evaluation system 1 according to this embodiment. The evaluation system 1 includes at least the contact 100 and sensors (force sensor 40, vibration sensor 50, etc.) illustrated in FIG. 1, as well as an evaluation device 2 illustrated in FIG.

[0049] The evaluation device 2 is a so-called computer, and includes a CPU (Central Processing Unit) 3, a memory 4, an input / output interface (I / F) 5, a communication unit 6, etc. The memory 4 is a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk, a portable storage medium, etc. The communication unit 6 communicates with other computers via a communication network and exchanges signals with other devices such as the sensor 9. A portable recording medium or the like can also be connected to the communication unit 6.

[0050] The input / output I / F 5 can be connected to an output device 7, an input device 8, etc. The output device 7 is a display device such as an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube) display, a printer, etc. The input device 8 is a device that accepts input of user operations such as a keyboard, a mouse, etc. However, the output device 7 and the input device 8 may be an integrated touch panel.

[0051] The evaluation device 2 may include hardware elements not shown in FIG. 6, and the hardware configuration of the evaluation device 2 is not limited to the example of FIG. In addition, in the example of Figure 6, for ease of explanation, a configuration is shown in which a sensor 9 such as the force sensor 40 or the vibration sensor 50 illustrated in Figure 1 is connected to the communication unit 6, but the sensor 9 may also be connected to the input / output I / F 5.

[0052] The evaluation system 1 executes the evaluation method according to each of the above-described embodiments, for example, by having the CPU 3 read and execute a computer program stored in the memory 4. Therefore, it can be said that the CPU 3 or the evaluation device 2 (computer) executes each step illustrated in FIGS. For example, the CPU 3 executes steps (S21) and (S22) to acquire measurement information from the sensor 9. The CPU 3 also executes step (S23) to generate evaluation information corresponding to the first and second physical properties related to the tactile feel of the test surface. Similarly, the CPU 3 executes steps (S41), (S42), and (S43) to acquire measurement information from the sensor 9. The CPU 3 executes step (S44) to classify the surface shape of the test surface, and executes step (S45) to generate evaluation information. The CPU 3 can also output the evaluation information generated in step (S23) or step (S45) to the output device 7. The evaluation information may be displayed on a display device or printed out by a printer.

[0053] The computer program may be stored in memory 4 in advance, or may be installed from a portable recording medium such as a CD (Compact Disc) or memory card, or from another computer on the network via input / output I / F 5 or communication unit 6, and then stored in memory 4.

[0054] Some or all of the above-described contents can also be specified as follows: However, the above-described embodiments are not limited to the following descriptions.

[0055] <1> A method for evaluating the tactile sensation of human skin or simulated skin based on information detected by a sensor when a contactor simulating the flexibility of a human finger is brought into contact with a test surface of the human skin or simulated skin that simulates human skin and an action to be evaluated is performed, the method comprising: an acquisition step of acquiring measurement information for each contact measured in association with the evaluation target action on the test surface using a first contact and a second contact that are different from each other in one or more physical properties among a plurality of physical properties that can cause a difference in tactile sensation; a generating step of generating evaluation information corresponding to a first physical property related to the tactile feel of the test surface and a second physical property different from the first physical property based on the acquired measurement information for each contact; Including, the first contactor has a higher sensitivity to the first physical property than to the second physical property; In the second contactor, sensitivity to the first physical property is lower than sensitivity to the second physical property. Evaluation method.

[0056] <2> In the acquiring step, measurement information for each contact is acquired for each of a plurality of test surfaces including one or both of one or more human skin test surfaces and one or more artificial skin test surfaces; In the generating step, the evaluation information is generated so that the acquired measurement information for each contact can be compared between test surfaces. <1> The evaluation method described in <3> In the acquiring step, measurement information for each contact is acquired for each of a plurality of test surfaces including one or both of one or more human skin test surfaces and one or more artificial skin test surfaces; In the generating step, the evaluation information is generated based on at least a difference between pieces of measurement information of the test surfaces obtained using the first contactor and a difference between pieces of measurement information of the test surfaces obtained using the second contactor. <1> The evaluation method described in <4> the sensor is capable of detecting one or both of friction and vibration; in the acquiring step, one or both of friction information and vibration information are acquired as measurement information by sliding the first contactor, the second contactor, or a third contactor having one or more physical properties different from those of the first contactor and the second contactor on the test surface, In the generating step, evaluation information regarding the surface shape of the test surface is further generated based on the acquired measurement information. <1> from <3> 10. The evaluation method according to claim 9, wherein <5> classifying the surface shape of the test surface using at least measurement information acquired in association with the operation to be evaluated on the test surface using the first contactor, the second contactor, or a third contactor having one or more physical properties different from those of the first contactor and the second contactor; Further comprising: In the generating step, the evaluation information corresponding to the first physical property and the second physical property related to the tactile feel of the test surface is generated based on the surface shape classification result and the acquired measurement information for each contact. <1> from <4> 10. The evaluation method according to claim 9, wherein <6> <1> from <5> A method for manufacturing a contact set of the first contact and the second contact used in the evaluation method according to any one of the preceding claims, preparing a plurality of first artificial skins that have the same second physical property and different first physical properties; preparing a plurality of second artificial skins having the same first physical property and different second physical properties; preparing a plurality of contacts each having one or more different physical properties among a plurality of physical properties that may cause a difference in tactile sensation; a step of acquiring first measurement information for each of the first simulated skins and each of the contacts while performing the action to be evaluated by bringing each of the plurality of contacts into contact with the plurality of first simulated skins; acquiring second measurement information for each of the second simulated skins and each of the contacts while performing the action to be evaluated by bringing each of the contacts into contact with the second simulated skins; selecting the first contactor and the second contactor from the plurality of contactors based on a difference between each first simulated skin of the first measurement information and a difference between each second simulated skin of the second measurement information; A method for manufacturing a contact set comprising: <7> the contact and the sensor, <1> from <5> An evaluation system capable of executing the evaluation method according to any one of the above.

[0057] The above content will be explained in more detail below with reference to examples, but the following examples do not limit the above content in any way. [Example]

[0058] In this example, evaluation and verification of physical properties related to the tactile sensation of artificial skin using multiple contacts and multiple artificial skins will be described. Figure 7(a) shows the characteristics of the six contacts used in this verification, and Figure 7(b) shows the characteristics of the seven simulated skins used in this verification. As shown in Figures 7(a) and 7(b), the six contacts used in this verification differ in one or more of the size of surface irregularities, surface texture, or hardness, and the seven simulated skins differ in one or more of the surface roughness, surface texture, or hardness. Hereinafter, the contacts indicated as "Finger 1" to "Finger 6" in FIG. 7(a) will be referred to as contacts 1 to 6, and the simulated skins indicated as "Simulated Skin A" to "Simulated Skin G" in FIG. 7(b) will be referred to simply as Simulated Skin A to Simulated Skin G.

[0059] The contactor used in this verification has the same configuration as the contactor 100 shown in Fig. 1, with the upper layer 10 and middle layer 20 made of urethane, and the lower layer 30 made of ASA resin. This three-layer structure achieves the surface shape and physical properties of each contactor shown in Fig. 7(a). Note that this verification differs from the example in Fig. 1 in that the force sensor 40 was placed under the simulated skin.

[0060] Specifically, the contact surface (upper layer 10) of each contactor that comes into contact with the test surface has a concave-convex shape that imitates a fingerprint, and the cross section of the convex part of the concave-convex shape is trapezoidal. The upper base of the trapezoid is set to 0.3 mm, the lower base is set to 0.5 mm, and the height is changed as shown by the size of the surface concave-convex in Figure 7(a). The contact surface of each contactor is coated with a different type of slipperiness, resulting in the different surface textures (dry or standard) shown in Figure 7(a). The surface texture labeled "dry" is slippery (friction coefficient 0.6), while the surface texture labeled "standard" is medium slipperiness (friction coefficient 0.8). The hardness of each contact is varied by changing the Young's modulus of the three layers: upper layer 10, middle layer 20, and lower layer 30. In Fig. 7(a), the hardness (softer) of a contact with a three-layer Young's modulus of 0.03 MPa is indicated as "30," and the hardness (harder) of a contact with a three-layer Young's modulus of 0.06 MPa is indicated as "40."

[0061] Regarding the surface roughness of each simulated skin in Figure 7(b), the arithmetic mean roughness (Ra) of 20.1 μm is labeled as "fine," the Ra of 23.7 μm is labeled as "medium," and the Ra of 29.4 μm is labeled as "coarse." The variations in the surface texture of each simulated skin were achieved by coating treatments with different slipperiness. In Figure 7(b), the surface texture labeled "Dry" is slippery (friction coefficient 0.5), the surface texture labeled "Standard" is medium slipperiness (friction coefficient 0.7), and the surface texture labeled "Moist" is not slippery (friction coefficient 1.1). Regarding the hardness of each simulated skin, those with a Young's modulus of 0.03 MPa are labeled "small" in Figure 7(b), those with a Young's modulus of 0.07 MPa are labeled "medium" in Figure 7(b), and those with a Young's modulus of 0.14 MPa are labeled "large" in Figure 7(b).

[0062] In this verification, friction information and vibration information were obtained as measurement information based on detection signals sent from the force sensor 40 and the vibration sensor 50 as the contacts were brought into contact with and slid over the test surface of the simulated skin. The contact was slid over a width of 5 cm at a speed of 10 cm / sec with a pressing force of 0.4 N. For vibration information, the vibration intensity (variance of amplitude) was calculated based on the detection signal from the vibration sensor 50, and for friction information, the friction coefficient (Fx / Fz) was calculated from the shear force (Fx) and shear force (Fz) based on the detection signal from the force sensor 40. Then, the average values of the vibration intensity and the friction coefficient obtained from the five measurements were calculated.

[0063] Figure 8(a) is a graph showing the friction coefficients of simulated skin A, B, and C for each of the six contacts (fingers 1 to 6), and Figure 8(b) is a graph showing the vibration intensity of simulated skin A, B, and C for each of the six contacts (fingers 1 to 6). The simulated skins A, B, and C have the same surface texture and hardness, but differ in surface roughness.

[0064] As shown in Figure 8(a), for all contactors, the greater the surface roughness, the greater the friction coefficient, revealing differences in the friction coefficient for each simulated skin. Furthermore, when the coefficient of variation of the friction coefficient for each contactor was calculated, the coefficients of variation for contactors 3 and 4 were 0.35 or greater, while the coefficients of variation for the other contactors were less than 0.3. Therefore, it can be seen that, particularly with contactors 3 and 4, differences in the surface roughness of the simulated skin can be accurately evaluated using the friction coefficient. Here, contacts 3 and 4 have the same surface texture and hardness, and the size of the surface irregularities is 0.06 mm and 0.1 mm. Therefore, when evaluating differences in skin surface roughness using the friction coefficient, it can be said that the evaluation accuracy is higher when the surface irregularities of the contacts are relatively small.

[0065] 8(b), the vibration intensity increases with increasing surface roughness for contacts 1, 3, 4, and 6, revealing differences in vibration intensity for each simulated skin. Furthermore, when the coefficient of variation of vibration intensity for each contact was calculated, the coefficient of variation for contacts 3 and 4 was 0.8 or greater, while the coefficient of variation for contacts 1 and 6 was 0.4 or greater and less than 0.6. Therefore, it can be seen that contacts 1, 3, 4, and 6 can accurately evaluate differences in the surface roughness of the simulated skin based on vibration intensity. Contacts 1, 3, 4, and 6 all have a common surface texture that is slippery, and the size of the surface irregularities is 0.2 mm or less. Therefore, when evaluating differences in skin surface roughness using vibration intensity, it can be said that the evaluation accuracy is higher when the contacts have a surface irregularity of 0.2 mm or less and a slippery surface texture. Furthermore, it can be said that the difference in the surface roughness of the artificial skin can be evaluated with high accuracy in both the friction coefficient and the vibration intensity.

[0066] Figure 9 is a graph showing the friction coefficients of simulated skin A, D, and E for each of the six contacts (fingers 1 to 6). Simulated skin A, D, and E have the same surface roughness and hardness, but each has a different surface texture. According to Figure 9, the friction coefficient increases with the surface texture of contacts 1, 5, and 6, revealing differences in the friction coefficient for each simulated skin. Furthermore, when the variance of the friction coefficient for each contact was calculated, the variance for contacts 1, 5, and 6 was 0.1 or greater, while the variance for the other contacts was less than 0.1. This demonstrates that contacts 1, 5, and 6 can accurately evaluate differences in the surface texture of the simulated skin based on the friction coefficient. In other words, contacts 1, 5, and 6 have a high sensitivity to the surface texture of skin.

[0067] Figure 10 is a graph showing the friction coefficients of simulated skin A, F, and G for each of the six contacts (fingers 1 to 6). Simulated skin A, F, and G have the same surface roughness and surface texture, but differ in hardness. According to Figure 10, the greater the hardness of contacts 2, 3, and 4, the smaller the friction coefficient, revealing differences in the friction coefficient for each simulated skin. Furthermore, when the variance of the friction coefficient for each contact was calculated, the variance for contacts 2, 3, and 4 was greater than 0.05, while the variance for the other contacts was less than 0.03. This shows that contacts 2, 3, and 4 can accurately evaluate differences in the hardness of the simulated skin based on the friction coefficient. In other words, contacts 2, 3, and 4 have a high sensitivity to skin hardness.

[0068] Here, it is difficult to evaluate differences in the hardness of the simulated skin using the friction coefficient for contacts 1, 5, and 6, and it is difficult to evaluate differences in the surface texture of the simulated skin using the friction coefficient for contacts 2, 3, and 4. In other words, the type of contacts 1, 5, and 6 (hereinafter sometimes referred to as the first type) and the type of contacts 2, 3, and 4 (hereinafter sometimes referred to as the second type) have mutually opposite sensitivities to the surface texture of the simulated skin and to the hardness of the simulated skin. In this verification, the contact sets of the first type contacts and the second type contacts differ from each other in one or two of the height of the surface irregularities, the surface properties, and the hardness.

[0069] FIG. 11 is a graph in which the vibration intensity and friction coefficient of seven simulated skin samples obtained using the contact 3 are plotted on a two-axis coordinate system. The vibration intensity used here was determined by the sum of the power spectral density (PSD) from 100 Hz to 150 Hz based on the detection signal from the vibration sensor 50. In FIG. 11, the vertical axis indicates vibration intensity, the horizontal axis indicates friction coefficient, and the average values of vibration intensity and friction coefficient for five measurements are plotted. The plot distribution shown in FIG. 11 shows that the degree of surface roughness of the artificial skin can be classified according to the positional relationship on the coordinate system.

[0070] In the example of Figure 11, the frequency band for vibration intensity is set to 100 Hz to 150 Hz. However, the accuracy of surface roughness classification can be improved by using a vibration intensity in a frequency band appropriate for the surface shape of the target surface. In this case, it is sufficient to store a frequency band appropriate for each surface shape of the target surface in advance. For example, since surface shape can also be evaluated using skin images, it is possible to evaluate the surface shape using skin images using an existing method and then select a frequency band corresponding to the evaluated surface shape.

[0071] Next, the friction coefficients of simulated skin samples with the same surface roughness but different surface textures or hardness or both were compared for each of the contact sets (contact 6 and contact 2) consisting of the first type contact and the second type contact. Figure 12(a) is a graph showing the friction coefficients of simulated skin A and E, which have the same surface roughness and hardness but different surface properties for contactor 6 and contactor 2, respectively; Figure 12(b) is a graph showing the friction coefficients of simulated skin A and F, which have the same surface roughness and surface properties but different hardness for contactor 6 and contactor 2, respectively; Figure 13(a) is a graph showing the friction coefficients of simulated skin G and E, which have the same surface roughness but different surface properties and hardness for contactor 6 and contactor 2, respectively; and Figure 13(b) is a graph showing the friction coefficients of simulated skin F and E, which have the same surface roughness but different surface properties and hardness for contactor 6 and contactor 2, respectively.

[0072] 12(a), there is a difference in the coefficient of friction between simulated skin A and simulated skin E for contactor 6, but there is almost no difference in the coefficient of friction for contactor 2. On the other hand, according to FIG. 12(b), there is a difference in the coefficient of friction between simulated skin A and simulated skin F for contactor 2, but there is almost no difference in the coefficient of friction for contactor 6. 13(a) and 13(b), there is a difference in the coefficient of friction between the two simulated skins for contacts 2 and 6, but while the order of magnitude of the difference is the same between the contacts in Fig. 13(a), the order of magnitude of the difference is reversed between the contacts in Fig. 13(b). Specifically, in the relationship between simulated skin G and simulated skin E, the coefficient of friction of simulated skin E is greater than the coefficient of friction of simulated skin G for both contacts 6 and 2, whereas in the relationship between simulated skin E and simulated skin F, the coefficient of friction of simulated skin E for contact 6 is greater than the coefficient of friction of simulated skin F, and the coefficient of friction of simulated skin F for contact 2 is greater than the coefficient of friction of simulated skin E. Here, between the simulated skin G and the simulated skin E in Figure 13(a), the simulated skin G has a slippery surface texture and is hard, while between the simulated skin F and the simulated skin E in Figure 13(b), the simulated skin F has a slippery surface texture and is hard.

[0073] From the above, if there is a difference in the coefficient of friction of the first type of contactor (contactor 6) but not the coefficient of friction of the second type of contactor (contactor 2), it can be determined that there is a difference in the surface texture between the simulated skins. If there is no difference in the coefficient of friction of the first type of contactor (contactor 6) but a difference in the coefficient of friction of the second type of contactor (contactor 2), it can be determined that there is a difference in hardness between the simulated skins. Furthermore, if there is a difference in the coefficient of friction between both the first and second type of contactors (contactors 6 and 2), it can be determined that there is a difference in both the surface texture and hardness between the simulated skins. Furthermore, if there is no difference in the coefficient of friction between both the first and second type of contactors (contactors 6 and 2), it can be determined that there is a difference in the surface texture and hardness between the simulated skins. In this way, by using a contact set consisting of a first type contact and a second type contact, it is possible to evaluate with high accuracy the surface texture and physical properties that can cause differences in the feel of the skin, as in each of the above-mentioned embodiments.

[0074] 12 and 13, the comparisons were conducted on artificial skin samples with the same surface roughness. Therefore, we investigated how the surface texture and hardness of the artificial skin would be evaluated if the differences in the surface roughness of the artificial skin samples were not excluded. Figure 14(a) is a graph plotting the friction coefficients of contactor 6 and contactor 2 for each of the simulated skins A, D, E, F, and G, which have the same surface roughness, on a two-axis coordinate system, and Figure 14(b) is a graph plotting the friction coefficients of contactor 6 and contactor 2 for each of the simulated skins A to G, on a two-axis coordinate system. According to Figure 14(a), which targets simulated skin excluding differences in surface roughness, it can be seen that the first type of contactor 6 can separate differences in surface properties without being affected by differences in hardness of the simulated skin, and the second type of contactor 2 can separate differences in hardness without being affected by differences in surface properties of the simulated skin. On the other hand, Figure 14(b), which covers all simulated skins without excluding differences in surface roughness, shows that it is difficult to separate differences in the surface properties and hardness of the simulated skin.

[0075] From the above, it has been demonstrated that, because differences in the surface roughness of the test surfaces reduce the evaluation accuracy of the surface texture and hardness of the test surfaces, it is possible to evaluate differences in surface texture and hardness with high accuracy between test surfaces with similar surface roughness. Therefore, as in the evaluation method according to the second embodiment described above, by classifying the test surfaces according to their surface shape (surface roughness, etc.), and then performing evaluations corresponding to the first and second physical properties (surface texture, hardness, etc.) of the test surfaces according to the classification to which the test surfaces belong, it is possible to perform a high-accuracy evaluation of physical properties related to tactile sensation.

[0076] In the flowcharts used in the above description, multiple steps (processes) are described in order, but the order of execution of the steps performed in each embodiment is not limited to the order described. In each embodiment, the order of the steps shown in the drawings can be changed to the extent that the content is not affected. Furthermore, the above-described embodiments can be combined to the extent that the content is not contradictory. [Explanation of symbols]

[0077] 1. Rating System 2 Evaluation equipment 3 CPU 4. Memory 5 Input / Output Interface 6 Communication Unit 7 Output Devices 8 Input Devices 9 Sensors 10 Upper Management 20 Middle Class 30 Lower part 40 Force Sensor 50 Vibration Sensor 100 contacts

Claims

1. A method for evaluating the tactile sensation of human skin or simulated skin based on information detected by a sensor when a contactor simulating the flexibility of a human finger is brought into contact with a test surface of the human skin or simulated skin that simulates human skin and an action to be evaluated is performed, the method comprising: an acquisition step of acquiring measurement information for each contact measured in association with the evaluation target action on the test surface using a first contact and a second contact that are different from each other in one or more physical properties among a plurality of physical properties that can cause a difference in tactile sensation; a generating step of generating evaluation information corresponding to a first physical property related to the tactile feel of the test surface and a second physical property different from the first physical property based on the acquired measurement information for each contact; Including, the first contactor has a higher sensitivity to the first physical property than to the second physical property; In the second contactor, sensitivity to the first physical property is lower than sensitivity to the second physical property. Evaluation method.

2. In the acquiring step, measurement information for each contact is acquired for each of a plurality of test surfaces including one or both of one or more human skin test surfaces and one or more artificial skin test surfaces; In the generating step, the evaluation information is generated so that the acquired measurement information for each contact can be compared between test surfaces. The evaluation method according to claim 1 .

3. In the acquiring step, measurement information for each contact is acquired for each of a plurality of test surfaces including one or both of one or more human skin test surfaces and one or more artificial skin test surfaces; In the generating step, the evaluation information is generated based on at least a difference between pieces of measurement information of the test surfaces obtained using the first contactor and a difference between pieces of measurement information of the test surfaces obtained using the second contactor. The evaluation method according to claim 1 .

4. the sensor is capable of detecting one or both of friction and vibration; in the acquiring step, one or both of friction information and vibration information are acquired as measurement information by sliding the first contactor, the second contactor, or a third contactor having one or more physical properties different from those of the first contactor and the second contactor on the test surface, In the generating step, evaluation information regarding the surface shape of the test surface is further generated based on the acquired measurement information. The evaluation method according to any one of claims 1 to 3.

5. classifying the surface shape of the test surface using at least measurement information acquired in association with the operation to be evaluated on the test surface using the first contactor, the second contactor, or a third contactor having one or more physical properties different from those of the first contactor and the second contactor; Further comprising: In the generating step, the evaluation information corresponding to the first physical property and the second physical property related to the tactile feel of the test surface is generated based on the surface shape classification result and the acquired measurement information for each contact. The evaluation method according to any one of claims 1 to 3.

6. A method for manufacturing a contact set of the first contact and the second contact used in the evaluation method according to any one of claims 1 to 3, comprising the steps of: preparing a plurality of first artificial skins that have the same second physical property and different first physical properties; preparing a plurality of second artificial skins having the same first physical property and different second physical properties; preparing a plurality of contacts each having one or more different physical properties among a plurality of physical properties that may cause a difference in tactile sensation; a step of acquiring first measurement information for each of the first simulated skins and each of the contacts while performing the action to be evaluated by bringing each of the plurality of contacts into contact with the plurality of first simulated skins; acquiring second measurement information for each of the second simulated skins and each of the contacts while performing the action to be evaluated by bringing each of the contacts into contact with the second simulated skins; selecting the first contactor and the second contactor from the plurality of contactors based on a difference between each first simulated skin of the first measurement information and a difference between each second simulated skin of the second measurement information; A method for manufacturing a contact set comprising:

7. the contact and the sensor, An evaluation system capable of executing the evaluation method according to any one of claims 1 to 3.

8. the contact and the sensor, An evaluation system capable of executing the evaluation method according to claim 5.

Images