KR20100058033A - Probe for tactile measurement device and the measurement device using it - Google Patents

Abstract

PURPOSE: A probe for a skin feeling measuring system, and a skin feeling measuring system using the same are provided, which can measure a spacious pattern of an object while measuring frictional force. CONSTITUTION: A probe for a skin feeling measuring system comprises: a 3-axis load cell(10) measuring the power of x, y, and z-axis; a probe tip(23) connected to a sinker and a stopper by a sensor bar; a sensor bar guide(30) guiding the vertical movement of the sensor bar; a probe(40) in which the inside contacts a sensor bar by a sensor bar guide and the bottom contacts a probe tip; and a laser displacement sensor(50) collecting the vertical displacement information of the probe tip.

Description

Probe for tactile measurement device and the measurement device using it}

The present invention relates to a probe for a skin tactile measurement device and a skin tactile measurement device using the same, and more particularly, for a skin tactile measurement device capable of measuring a motion friction coefficient and viscoelasticity of a surface (skin) of a subject by tracking a path of movement. The present invention relates to a probe and an apparatus for measuring skin feel using the same.

The motion friction coefficient is the ratio of the horizontal drag acting in the direction horizontal to the contact surface and the vertical drag acting in the direction perpendicular to the contact surface, which is an interaction force generated when two objects move relatively in the state of maintaining contact.

This motion friction coefficient can be measured by using a multi-axis force sensor (load cell), in this case, the horizontal axis force X and the vertical axis force Y are multiaxially moved by horizontally moving the object while the contact surface is held vertically with a probe. It is possible to configure a device to measure by using a sensor, wherein the motion friction coefficient corresponds to the ratio X / Z.

On the other hand, since the skin, which is the measurement object of the skin tactile measuring device, has a slope and curvature according to the curvature, since the horizontal axial force X and the vertical axial force Y are not the horizontal drag and the vertical drag on the contact surface, the X / Z is true. It is not a coefficient of motion friction, and it is a quantity that varies greatly depending on the bending pattern even if it is made of the same material.

Therefore, in order to properly measure the motion friction coefficient of the skin, a means for simultaneously measuring the spatial pattern of skin flexion is required while measuring the frictional force.

In order to solve the problems as described above, in the present invention, while measuring the frictional force such as horizontal drag, vertical drag, etc., in order to measure the motion friction coefficient, the spatial pattern (vertical displacement) of the object (skin) curvature may be simultaneously measured. The present invention also provides a probe for a skin tactile measurement device that can be converted into a device for measuring viscoelasticity, and a skin tactile measurement device using the same.

Probe for skin tactile measurement device according to the present invention for achieving the above object,

a three-axis load cell capable of measuring forces in three directions of x, y, and z axes; A probe tip connected to the weight and the stopper by the sensor bar; Sensor bar guide for guiding the vertical movement of the sensor bar; An upper end connected to a lower surface of the triaxial load cell, a lower end contacting the probe tip, and an inside of the probe contacting the sensor bar by the sensor bar guide; And a laser displacement sensor that is fixed to the lower surface of the triaxial load cell in a space formed by the probe and collects vertical displacement information of the probe team.

The shape of the probe tip is preferably any one of a spherical shape, a hemispherical shape, a cone shaped curved end, and a polygonal curved curved end.

The laser displacement sensor is preferably formed on an extended central axis of the sensor bar. On the other hand, by placing the laser beam reflecting end moving with the probe outside the probe may be implemented in the laser displacement sensor outside the probe.

The laser displacement sensor may include a light emitting part for emitting a laser toward the sensor bar, and a light receiving part for receiving a laser reflected by the sensor bar.

The laser displacement sensor may further include a counter weight for removing an offset of a force signal applied to the triaxial load cell.

In addition, a pin hole through which pins may be formed may be formed on side surfaces of the probe, the sensor bar, and the sensor bar guide, and vertical movement of the sensor bar and the sensor bar guide may be performed by inserting a pin through the pin hole. Blockade to determine the viscoelasticity of the subject.

Skin tactile measurement device according to the present invention,

The above-described probe for measuring skin feel; A driving unit for driving the pro unit; A signal amplifier for amplifying the force signal and the displacement signal measured by the probe; An arithmetic operation unit for arithmetic processing the signal amplified by the signal amplification unit; And a display unit for displaying the calculated result.

The drive unit preferably includes a motor.

The signal amplifier preferably includes a multi-channel amplifier for amplifying the force signal measured by the probe and a data acquisition (DAQ) unit for amplifying the vertical displacement signal measured by the probe.

The calculation unit calculates the motion friction coefficient according to Equation (1) when the probe scans while traveling back along the curvature of the object surface.

Equation (1):

Where μ is the motion friction coefficient, T is the motion friction force, N is the vertical drag, X is the horizontal force, Z is the vertical force, and θ is the inclination angle of the contact surface of the object surface and the probe.

In addition, the calculation unit calculates the motion friction coefficient by the following equation (2) when the probe is scanned along the curvature of the object surface.

Equation (2):

Where μ is the motion friction coefficient, T is the motion friction force, N is the vertical drag, X is the horizontal force, Z is the vertical force, and θ is the inclination angle of the contact surface of the object surface and the probe.

According to the probe for the skin tactile device according to the present invention as described above and the skin tactile device using the same,

While measuring the frictional force, there is an effect that can simultaneously measure the spatial pattern (vertical displacement) of the object (skin) curvature.

In addition, the probe of the present invention is not fixed to a predetermined portion of the device, but can be designed in a movable form, there is an effect that can increase the convenience of the user.

In addition, in the case of the conventional probe, if there is no vertical displacement information, assuming that the object (skin) is a flat structure, the ratio of the horizontal axis force (X) and the vertical axis force (Z), which are reaction forces read by the multiaxial force sensor, is calculated as the average motion friction coefficient. However, in the present invention, since the horizontal displacement as well as the vertical displacement can be measured simultaneously by the probe, the spatial bending information of the object can be obtained, and thus the true average motion friction coefficient of the object can be measured. It works.

In addition, there is an advantage that can measure the viscoelasticity of the object using only a pin without having a separate equipment.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention; First, it should be noted that the same components or parts in the drawings represent the same reference numerals as much as possible. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the gist of the present invention.

1 is a cross-sectional view showing a probe for a skin tactile measurement device according to an embodiment of the present invention, Figure 2 is a cross-sectional view showing a probe for a skin tactile measurement device according to another embodiment of the present invention, Figure 3 is 4 is a block diagram illustrating a skin tactile measurement device according to an embodiment, and FIG. 4 is a view illustrating a scanning process of a probe for a skin tactile measurement device according to an embodiment of the present invention, which goes up a slope along a curve of an object; FIG. 5 is a diagram illustrating a scanning process of a probe for a skin tactile measurement device according to an embodiment of the present invention, and illustrates a case where the inclination is lowered along the curvature of an object.

As described above, in order to properly measure the motion friction coefficient of the skin, a means for simultaneously measuring the spatial pattern of skin flexion is required while measuring the frictional force. By using both the skin flexion information and the force (X, Y) information obtained by the multiaxial force sensor, the true motion coefficient can be obtained through the analysis of the component force. A probe for a skin tactile measurement device according to an embodiment of the present invention for implementing this is shown in FIG. 1.

Referring to FIG. 1, a probe for a skin tactile measurement device according to the present invention includes a three-axis load cell 10, a sensor bar 24, a weight 21, a stopper 22, a probe team 23, and a sensor bar guide. 30, a probe 40, and a laser displacement sensor 50.

The three-axis load cell 10 is a three-axis force-moment sensor that can measure the force and the moment in the x-axis, y-axis, and z-axis three directions, the present invention uses a conventional three-axis load cell.

Meanwhile, the probe tip 23 is connected to one end of the sensor bar 24, and is contacted or separated from the skin of the object by vertical movement (or vertical movement) of the sensor bar 24. At this time, the shape of the probe tip is preferably any one of a spherical shape, a hemispherical shape, a cone curved end, a polygonal curved end is curved in order to minimize the area of the contact portion with the object (skin).

A weight 21 is formed at the other end of the sensor bar 24 so as to apply a constant weight to the probe tip. The weight is fixed to the sensor bar is formed integrally, or may be formed detachably removable. A stopper 22 is formed below the weight 21 to support the weight of the weight and to prevent the sensor bar 24 from being separated from the sensor bar guide 30.

A sensor bar guide 30 is formed below the stopper 22 to guide the vertical movement of the sensor bar 24 and to transmit the horizontal force and the vertical force generated when the probe moves to the probe to be sensed by the three-axis load cell. have.

The probe 40 has an upper end connected to a lower surface of the triaxial load cell so that the horizontal force and the vertical force received by the sensor bar guide 30 are transmitted to the triaxial load cell, and the lower end thereof is in contact with the probe tip 23. It is formed to be sealed by the sensor bar guide formed in a predetermined region therein.

The laser displacement sensor 50 is fixed to the lower surface of the triaxial load cell in an area enclosed by the triaxial load cell 10, the sensor bar guide 30, and the probe 40. Preferably, the laser displacement sensor 50 is formed on the extended central axis of the sensor bar 24, and when the probe tip 23 moves along the surface valley of the object to scan, the upper and lower sides of the probe team Collect the vertical displacement information of the sensor bar that changes with the movement. Alternatively, the laser reflecting end moving together with the probe may be formed outside the probe by protruding to the outside. The laser displacement sensor 50 includes a light emitting part (not shown) for emitting a laser toward the sensor bar 24, and a light receiving part (not shown) for receiving a laser reflected by the sensor bar. In addition, the laser displacement sensor 50 may further include a counter weight (not shown) for removing the offset of the force signal applied to the three-axis load cell.

In the known device, the laser displacement sensor 50 is installed outside of the probe without being interlocked with the probe. In this case, since the laser directly irradiates the surface of the object, that is, the skin surface, fine wrinkles and Scattering or diffuse reflection by the hair will result in the inaccurate collection of the vertical displacement. However, in the present invention, by providing a laser displacement sensor in the probe, it is possible to fundamentally solve the problems occurring in the conventional apparatus.

2 is a probe for a skin tactile measurement device according to another embodiment of the present invention. As shown in FIG. 2, the probe for measuring the skin sensation according to another embodiment of the present invention is identical to the probe of the above-described embodiment except for the pinhole 60 and the pin 61. Therefore, description of the parts other than the pinhole and the pin will be omitted.

While the probe shown in FIG. 1 is a probe for measuring a motion friction coefficient, the probe shown in FIG. 2 is a probe for measuring viscoelasticity of an object, and the probe 40 and the sensor bar ( 24, and a pinhole 60 through which the pin 61 penetrates the side of the sensor bar guide 30.

By inserting the pin 61 into the pinhole 60, the vertical motion of the sensor bar 24 and the sensor bar guide 30 may be blocked to measure viscoelasticity of the object. At this time, the laser light of the laser displacement sensor is turned off.

The viscoelastic properties of the sample are determined by the indentation load-indentation depth curve obtained through the indentation test by pressing the sample into the probe and retracting the probe at the loading state and loading depth. It can be evaluated from hysteresis, which is separated from unloading under unloading. When entering the unloaded state at the maximum pressed depth, the load-depth curve falls below the curve of the loaded state and does not return to the original displacement even when the force is completely removed. The sharper the elasticity, the higher the viscous slope of the indentation load-depth curve in the unloaded state.

 The probe for the viscoelasticity measuring device having the configuration as shown in FIG. 2 forms a pinhole 60 in the probe for motion friction coefficient shown in FIG. 1, and since only the pin 61 is inserted separately, the viscoelastic characteristic is easily available without a separate device. There is an advantage in performing indentation tests to evaluate That is, when the pin 61 is inserted into the pinhole 60, the probe including the load cell 10 is moved up and down to perform the indentation test.

As shown in FIG. 3, the skin tactile measurement device according to an embodiment of the present invention may include a skin tactile probe 100, a driver 200, a signal amplifier 300, a calculator 400, and a display unit. 500.

The skin tactile probe 100 is a probe described with reference to FIGS. 1 and 2 and measures horizontal forces Fx, Fy, vertical forces Fz, and vertical displacement ΔZ. Therefore, description thereof is omitted.

The driver 200 is a part for driving the probe 100 by a drive control device such as a computer, and includes at least one motor.

The signal amplifier 300 amplifies the force signal and the displacement signal measured by the probe. The signal amplifier 300 amplifies the multi-channel amplifier 310 for amplifying the force signals Fx, Fy, and Fz measured by the probe and the vertical displacement signal ΔZ measured by the probe. It is preferable to include a data collector 320 for.

The multi-channel amplifier 310 may be composed of three signal conditioning units, and performs a function of removing noise and amplifying a force signal. In addition, the data collector 320 may include a noise filter and an AD converter, and performs a function of acquiring vertical displacement data as a digital value.

The force signals fx, fy, fz and the vertical displacement signal Δz amplified by the signal amplifier 300 are input to an operation unit 400 such as a computer, for example. The calculation unit 400 calculates the motion friction coefficient or the viscoelastic coefficient by calculating and processing the input force signal and the vertical displacement signal.

At this time, a calculation processing procedure in the calculation unit will be described with reference to FIGS. 4 and 5. FIG. 4 illustrates a case in which the probe is scanned while traveling back along the curvature of the object surface. Here, T is the frictional force, N is the vertical drag, W is the weight of the weight and the tip, X is the horizontal component of the reaction force, Z is the vertical component of the reaction force, θ is the inclination angle of the contact surface of the object surface and the probe. Also, the arrow at the top shows the scanning direction of the probe. Referring to the horizontal force X, the load cell 10 detects X as the horizontal force by the force that the sensor bar guide 30 pushes the probe tip 23 horizontally while the probe is moving. In addition, when the vertical force Z is described in detail, as a reaction force component in which an object (skin) lifts up the probe tip 23, the load cell 10 detects Z, which is a vertical component of the reaction force, as a vertical force.

Referring to FIG. 4, X = Tcosθ + Nsinθ and Z = Ncosθ-Tsinθ-W. Under the condition that the probe scans horizontally at constant speed, the sum of the horizontal components of the forces present is always zero. Also, ideally, if the probe's motion is steady-state, 'Z = W', otherwise 'Z ≠ W'. If the slope of the tangent plane does not change during the scan of the probe, it is steady-state.

Therefore, when this is put together and the equation is put together, it becomes as following formula (1).

Equation (1):

Where μ is the motion friction coefficient.

5 illustrates a case in which the probe scans while descending along the curvature of the object surface. Here, reference numerals are the same as those shown in FIG. 4. The arrow shown at the top shows the scanning direction of the probe.

Referring to FIG. 5, X = Tcosθ-Nsinθ and Z = Ncosθ + Tsinθ-W. Under the condition that the probe scans horizontally at constant speed, the sum of the horizontal components of the forces present is always zero. Also, ideally, if the probe's motion is steady-state, 'Z = W', otherwise 'Z ≠ W'. At this time, if the inclination of the tangent plane does not change during the scan of the probe is a steady-state.

Therefore, when this is summed up and summed up, it becomes as following formula (2).

Equation (2):

Where μ is the motion friction coefficient.

Viscoelastic properties of the sample can be obtained by the indentation test (indentation test) to obtain the indentation load-indentation depth curve. In the indentation test, the propagation speed of the probe and the maximum allowable indentation load are kept constant so that the force (indentation load) -displacement (depth) curve can be obtained, and the slopes of the loaded and unloaded states can be presented as elastic and viscous characteristics. have.

The display unit 500 displays the tactile characteristics of the object (skin) by displaying two inclinations of the motion friction coefficient calculated through the operation of the calculation unit 400 or the load state and the unload state of the indentation load-displacement curve. Display.

As described above with reference to the drawings illustrating a skin tactile measurement device probe and a skin tactile measurement device using the same, but the present invention is not limited by the embodiments and drawings disclosed herein, Of course, various modifications may be made by those skilled in the art within the scope of the technical idea of the present invention.

1 is a cross-sectional view showing a probe for a skin tactile measurement device according to an embodiment of the present invention;

2 is a cross-sectional view showing a probe for a skin tactile measurement device according to another embodiment of the present invention;

3 is a block diagram showing an apparatus for measuring skin sensation according to an embodiment of the present invention;

FIG. 4 is a diagram illustrating a scanning process of a probe for a skin tactile measurement device according to an embodiment of the present invention, which illustrates a case in which a slope is traced along the curvature of an object; FIG.

FIG. 5 is a diagram illustrating a scanning process of a probe for a device for measuring skin sensation according to an embodiment of the present invention, illustrating a case where the inclination is lowered along the curvature of an object.

<Description of the symbols for the main parts of the drawings>

10: 3-axis load cell 21: Weight

22: stopper 23: probe tip

24: sensor bar 30: sensor bar guide

40: probe 50: laser displacement sensor

60: pinhole 61: pin

100: probe 200: drive unit

300: signal amplifier 400: calculator

500: display unit

A: Subject (skin)

Claims (11)

a three-axis load cell capable of measuring forces in three directions of x, y, and z axes; A probe tip connected to the weight and the stopper by the sensor bar; Sensor bar guide for guiding the vertical movement of the sensor bar; An upper end connected to a lower surface of the triaxial load cell, a lower end contacting the probe tip, and an inside of the probe contacting the sensor bar by the sensor bar guide; And, The laser displacement sensor is fixed to the lower surface of the three-axis load cell in the space formed by the probe, collecting the vertical displacement information of the probe team Probe for skin tactile measurement device comprising a. The method according to claim 1, The probe tip has a spherical shape, a hemispherical shape, the end of the curved cone-shaped, the end is curved any one of the polygonal pyramid-treated probe for the skin tactile measurement device. The method according to claim 1, And the laser displacement sensor is formed on an extended center axis of the sensor bar or outside the probe by protruding a laser reflective end moving together with the probe to the outside. The method according to claim 1, The laser displacement sensor includes a light emitting part for emitting a laser toward the sensor bar, and a light receiving part for receiving a laser reflected by the sensor bar. The method according to claim 1, The laser displacement sensor further comprises a counter weight for removing the offset of the force signal applied to the three-axis load cell probe for skin tactile measurement device. The method according to claim 1, Pinholes are formed in the side of the probe, the sensor bar, and the sensor bar guide penetrates the pin, penetrates the pinhole to block the vertical movement of the sensor bar and the sensor bar guide. Probe for skin tactile measurement device, characterized in that the viscoelasticity of the subject can be measured. The skin tactile probe according to any one of claims 1 to 6; A driving unit for driving the pro unit; A signal amplifier for amplifying the force signal and the displacement signal measured by the probe; An arithmetic operation unit for arithmetic processing the signal amplified by the signal amplification unit; And, A display unit for displaying the calculated result Skin tactile measurement device comprising a. The method of claim 7, The skin tactile measurement device, characterized in that the drive unit comprises a motor. The method of claim 7, The signal amplification unit includes a multi-channel amplifier for amplifying the force signal measured by the probe and a data acquisition (Data Aquisition, DAQ) unit for amplifying the vertical displacement signal measured by the probe. Measuring device. The method of claim 7, Wherein the calculation unit when the probe is scanned while traveling up the curvature of the surface of the object, the skin tactile measurement device, characterized in that for calculating the motion friction coefficient by the following formula (1) Equation (1):

(Where μ is the coefficient of motion friction, T is the motion friction force, N is the normal drag, X is the horizontal force, Z is the vertical force, and θ is the angle of inclination of the contact surface of the object surface and the probe). The method of claim 7, Wherein the calculation unit when the probe scans along the curvature of the object surface, the skin tactile measurement device, characterized in that for calculating the motion friction coefficient by the following formula (2) Equation (2):

(Where μ is the coefficient of motion friction, T is the motion friction force, N is the normal drag, X is the horizontal force, Z is the vertical force, and θ is the angle of inclination of the contact surface of the object surface and the probe).

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