KR20190137395A - Sensing device - Google Patents

Abstract

Disclosed is a sensing device. According to an embodiment of the present invention, the sensing device comprises: a sensor main body including a main body center part, a main body outer surface part arranged so as to surround the outside of the main body center part, and a plurality of sensing bridges extending from an outer surface of the main body center part toward an inner surface of the main body outer surface part; a plurality of strain gauges installed in the plurality of sensing bridges; and a plurality of detection circuit parts for detecting a change in resistance of the plurality of strain gauges. The plurality of strain gauges are connected one-to-one with the plurality of detection circuit parts. Therefore, the sensing device can independently measure and use a resistance value of a plurality of strain gauges.

Description

Sensing Device {SENSING DEVICE}

The present invention relates to a sensing device that independently measures and utilizes resistance values of a plurality of strain gauges.

In industrial articulated robots or actuators, torque sensors can be used. The torque sensor may be provided to measure torque (rotation moment) generated by forces in various directions. For example, the torque may include a torque (axial moment about the z axis) and a bending (or torsional) moment about the x and y axes of the motor.

In order to easily sense the torque, the torque sensor may include a sensor body and a plurality of strain gauges attached to the sensor body.

A strain gauge is a measure of the strain of a structure based on the strain gauge attached to the structure when the structure causes deformation so that the electrical resistance changes.

On the other hand, a bridge circuit is used to detect a change in the resistance of the strain gauge.

Referring to FIG. 9, conventionally, one bridge circuit is composed of resistors RG1 + ΔR1, RG2 + ΔR2, RG3 + ΔR3, RG4 + ΔR4 of a plurality of strain gauges, and the output voltage VO of the bridge circuit is changed. The change of the resistance of several strain gauge was measured.

The relationship between the output voltage Vo and the input voltage Vex can be expressed by the following equation.

In the above formula, RG1, RG2, RG3, and RG4 are basic resistance values of strain gauges constituting one bridge circuit, and ΔR1, ΔR2, ΔR3, and ΔR4 are resistance change values of the strain gauges.

When the bridge circuit is composed of four strain gauges as shown in FIG. 9, the resistors RG1 + ΔR1, RG2 + ΔR2, RG3 + ΔR3, RG4 + ΔR4 of the plurality of strain gauges do not operate independently of each other as shown in the above equation. And all of the resistances of the plurality of strain gauges affect the output voltage VO.

Normally, adjust RG1 = RG2 = RG3 = RG4 so that the output voltage is “0”. This is offset calibration. In this case, adjust each strain gauge by connecting a small resistor in series.

However, because these resistors have a change rate with temperature, it is very difficult to calibrate correctly. In addition, ΔR1 ΔR2 ΔR3 and ΔR4, which are resistance change values, indicate the sensitivity of the sensor.

Therefore, the conventional method is very difficult to calibrate, especially when a bending moment occurs along with the rotation moment, it may be difficult to correct the rotation moment by accurately measuring the bending moment. In addition, even if one strain gage failed, there could be a problem that the torque cannot be measured.

Typically, industrial articulated robots or actuators, in addition to rotational moments, bending moments may occur in various directions. Therefore, by using a plurality of strain gauges, the necessity of correcting the rotation moment by accurately measuring not only the rotation moment but also the bending moment occurring in various directions has emerged.

The present invention is to solve the above problems, an object of the present invention is to provide a sensing device for independently measuring and utilizing the resistance value of a plurality of strain gauges.

The sensing device according to the present embodiment includes a main body, a main body outer surface disposed to surround the outside of the main body central portion, and a sensor main body including a plurality of sensing bridges extending from the outer surface of the main body central portion toward the inner surface of the main body outer surface portion. And a plurality of strain gauges provided in the plurality of sensing bridges, and a plurality of detection circuit units for detecting a change in resistance of the plurality of strain gauges, wherein the plurality of strain gauges are one-to-one with the plurality of detection circuit units. Leads to.

In this case, the resistance of each of the plurality of strain gauges may constitute a resistance of the bridge circuit connected one-to-one.

Meanwhile, the plurality of strain gauges may be installed at both sides of each of the plurality of sensing bridges.

In this case, the controller further determines at least one of a rotation moment based on an axial direction and a bending moment based on a radial direction based on a change in resistance of the plurality of strain gauges respectively detected by the plurality of detection circuit units. It may include.

In this case, when the resistance of the strain gauges installed on the first side of each of the plurality of sensing bridges increases and the resistance of the strain gauges installed on the second side of each of the plurality of sensing bridges decreases, It can be determined that the rotation moment based on the applied.

The controller may determine a direction of a bending moment applied to the sensor body based on at least one of increasing and decreasing resistances of the plurality of strain gauges respectively detected by the plurality of detection circuit units.

In this case, the control unit, the resistance of the first strain gauge provided on one side of the first sensing bridge and the resistance of the second strain gauge provided on one side of the second sensing bridge facing one side of the first sensing bridge is the same. Decreasingly, the direction of the bending moment generated by the force acting on the first line is determined, wherein the first line forms an acute angle with the first sensing bridge and the second sensing bridge, The angle formed by the first sensing bridge may be the same as the angle formed by the first line and the second sensing bridge.

On the other hand, the control unit, if the resistance of the third strain gauge provided on one side of the first sensing bridge and the resistance of the fourth strain gauge provided on the other side of the first sensing bridge equally decreases, the force acting on the second line Determine a direction of bending moment generated by the second line, wherein the second line forms an acute angle with one side of the first sensing bridge and the other side of the first sensing bridge, and the second line and the first sensing bridge The angle formed by one side of may be the same as the angle formed by the second line and the other side of the first sensing bridge.

In the present invention, the resistance change of each strain gauge can be independently measured by connecting the resistances of the plurality of strain gauges to the plurality of detection circuits one by one. Therefore, calibration by bending moment, linear correction, temperature correction, sensitivity correction, and the like can be easily and accurately performed, and there is an advantage in that torque can be measured even when any strain gauge fails.

In addition, the present invention, when a plurality of strain gauges are installed on the side for the measurement of the rotation moment, because the bending moment is measured by combining the values measured in the same strain gauge, it is possible to improve the accuracy of the measurement and reduce the cost There is an advantage.

In addition, even when a bending moment occurs due to a force acting on a line without a strain gage on the XY plane, by measuring the values measured in the plurality of strain gages together, the exact direction and size of the bending moment can be measured. There is an advantage.

Also, the sensing device basically measures the rotation moment based on the Z-axis direction, but when the bending moment occurs together, the sensing device cannot measure the accurate rotation moment. However, since the present invention blocks the interaction between the strain gauges by independently measuring the resistance change of each strain gauge, the bending moment can be accurately measured and the correction of the influence of the bending moment can be easily performed. .

1 is a front perspective view showing a configuration of a torque sensor according to a first embodiment of the present invention.
2 is a rear perspective view showing the configuration of the torque sensor according to the first embodiment of the present invention.
3 is an exploded perspective view showing the configuration of the torque sensor according to the first embodiment of the present invention.
4 is a perspective view showing the configuration of a sensor main body according to a first embodiment of the present invention.
5 is a front view showing the configuration of the sensor body according to the first embodiment of the present invention.
6 is a cross-sectional view taken along line VI-VI 'of FIG. 1.
7 is a cross-sectional view showing the configuration of a power transmission device including a torque sensor according to the first embodiment of the present invention.
8 is a front view showing the configuration of the sensor body according to the second embodiment of the present invention.
9 is a view showing a conventional detection circuit.
10 is a block diagram illustrating a sensing device according to an embodiment of the present invention.
11 is a front view of a sensor main body for explaining an arrangement of a plurality of strain gauges according to an exemplary embodiment of the present disclosure.
FIG. 12 is a diagram illustrating a first detection circuit unit 1010 connected to a first strain gauge 1011 according to an exemplary embodiment of the present invention.
FIG. 13 is a diagram for describing a method of determining a rotation moment when a rotation moment is generated based on an axial direction, that is, a Z axis direction, according to an embodiment of the present disclosure.
FIG. 14 is a diagram illustrating a case where a torque based on the Y axis direction, that is, a bending moment based on the Y axis direction is generated.
FIG. 15 is a diagram illustrating a case where a torque based on a 60 degree direction from the Y axis, that is, a bending moment based on a 60 degree direction from the Y axis occurs.
16 is a diagram illustrating a case in which a torque based on a 30 degree direction from the Y axis, that is, a bending moment based on a 30 degree direction from the Y axis occurs.
FIG. 17 is a front view of a sensor main body for explaining an arrangement of a plurality of strain gauges, according to another exemplary embodiment.

Hereinafter, with reference to the drawings will be described a specific embodiment of the present invention. However, the spirit of the present invention is not limited to the embodiments presented, and those skilled in the art who understand the spirit of the present invention can easily suggest other embodiments within the scope of the same idea.

1 is a front perspective view showing a configuration of a torque sensor according to a first embodiment of the present invention, FIG. 2 is a rear perspective view showing a configuration of a torque sensor according to a first embodiment of the present invention, and FIG. 4 is an exploded perspective view showing the configuration of the torque sensor according to the first embodiment, and FIG. 4 is a perspective view showing the configuration of the sensor main body according to the first embodiment of the present invention.

1 to 4, the torque sensor 100 according to the first embodiment of the present invention is coupled to a power device 200 (see FIG. 7) to torque by a force generated by the power device 200. I can detect it.

Define the direction. Based on the torque sensor 100, the output side of the power unit 200, that is, the direction in which the speed reducer 250 is located is referred to as "forward", the opposite direction, that is, the direction in which the load device (not shown) is coupled Name it "Rear". The direction in which the shaft 212 of the power unit 200 extends is called "axial direction" or "z-axis direction", and the direction perpendicular to the axis direction based on FIG. 7 is called "radial direction". do. In addition, the radial direction may include “x axis direction” and “y axis direction” (see FIG. 4).

The torque sensor 100 includes a sensor body 110 on which a sensor board 150 is installed. For example, the sensor body 110 may have a ring shape.

The sensor main body 110 includes a main body central portion 111 on which the sensor board 150 is installed, a plurality of bridges 120 and 130 extending radially from the main body central portion 111, and a plurality of bridges 120 and 130. A body outer surface 112 is formed to connect the radially outer end of the body to form an outer circumferential surface of the sensor body 410.

The plurality of bridges 120 and 130 include a reinforcement bridge 120 and a strain gauge 140 for reinforcing the rigidity of the sensor main body 110 to sense torque 130.

The main body outer surface portion 112 has a ring shape and may be disposed to surround the outer side of the main body central portion 111. In addition, the main body outer surface portion 112 may include an external component, for example, a first external fastening portion 118 fastened to the power unit 200. A plurality of first external fastening parts 118 may be provided and arranged in the circumferential direction.

The body central portion 111 may have a substantially cylindrical shape. The main body 111 may include a second external fastening part 119 fastened to an external component, for example, a load device (not shown). A plurality of second external fastening parts 119 may be provided and arranged in the circumferential direction.

The sensor board 150 may be disposed in the depression 114 of the sensor body 110. The depression 114 is understood as a space portion that is recessed inside the central portion of the sensor body 110 when viewed based on the outer surface 112 of the main body, and provides a space in which the sensor board 150 is accommodated. can do.

In addition, the sensor board 150 may be positioned at the front of the main body 111 and may be supported by the board seating part 125 provided in front of the plurality of bridges 120 and 130. In detail, the board seating part 125 may protrude forward from the front surface of the reinforcing bridge 120 among the plurality of bridges 120 and 130 and support the rear surface of the sensor board 150.

As the sensor board 150 is supported by the board seating part 125, the rear surface of the sensor board 150 may be positioned to be spaced apart from the central portion 111 of the main body 111 by S1 (see FIG. 6).

The sensor board 150 may be positioned to be spaced forward from the sensing bridge 130 among the plurality of bridges 120 and 130. That is, the board seating part 125 may form a “chin” such that the sensor board 150 is supported by the reinforcing bridge 120 and not supported by the sensing bridge 130.

 By such arrangement, since the force transmitted from the sensor board 150, for example, the fastening force of the sensor board 150 does not directly act on the sensing bridge 130, a force other than the torque to be sensed is applied to the sensing bridge 130. 130 may be prevented from acting on strain gauge 140.

The board seating part 125 may be located at a radially outer side of the reinforcing bridge 120 and may be coupled to an inner circumferential surface of the main body outer surface part 112. In addition, a plurality of board seating portions 125 may be provided and spaced apart in the circumferential direction. For example, three board seating portions 125 may be provided.

The board seating part 125 has a body fastening hole 126 to which the board fastening member 161 is coupled. The board fastening member 161 is coupled to the front cover fastening hole 184 of the front cover 180 and penetrates the board fastening hole 155 of the sensor board 150 to be fastened to the main body fastening hole 126. Can be. The body fastening holes 126 may be formed in plural numbers corresponding to the number of the board seating portions 125. By this fastening structure, the sensor board 150 may be stably fastened to the sensor body 110.

The sensor main body 110 further includes a protrusion 113 protruding forward from the main body central part 111. The protrusion 113 may have a hollow cylindrical shape, and a body penetrating portion 117 may be formed in the protrusion 113 in which a device cable connected to the power unit 200 is located. The device cable may be understood as a cable that is connected to the power unit 200 to transmit an electrical signal. In addition, the depression 114 may be defined as an outer space of the protrusion 113.

The body through part 117 may be formed from the inside of the body center part 111 to the inside of the protrusion part 113.

The sensor board 150 has a disc shape and a plurality of sensing components 151 may be installed. In the substantially center portion of the sensor board 150, a board through-hole 156 into which the protrusion 113 is inserted is formed. When the sensor board 150 is coupled to the sensor body 110, the protrusion 113 may be inserted into the board through hole 156 to protrude forward.

The sensor board 150 further includes a connector port 158 to which the connector 170 may be coupled. The board cable 172 may be connected to the connector port 158 to transmit an electrical signal of the sensor board 150 to the outside, or to transmit an external electrical signal to the sensor board 150.

For example, the board cable 172 may connect the strain gauge 140 and the sensor board 150. Although not shown in the drawing, a hole may be formed in the sensor body 110 to guide the position of the board cable 172. By this cable guide structure, it is possible to reduce the occurrence of noise in the signal transmitted between the strain gauge 140 and the sensor board 150.

The torque sensor 100 includes a front cover 180 coupled to the front portion of the sensor body 110 and a rear cover 190 coupled to the rear portion of the sensor body 110.

The front cover 180 includes a front cover body 181 having a substantially disc shape and a front cover through portion 182 formed at the center of the front cover body 181 and aligned with the board through hole 156. Included. The device cable extends in the front-rear direction through the main body penetrating portion 117 and the front cover penetrating portion 182, and may be connected to the power unit 200.

The front cover 180 further includes a port through part 183 into which the connector port 158 is inserted. The connector port 158 may be exposed to the outside through the port through part 183.

The front cover body 181 includes a front cover fastening hole 184 aligned with the board fastening hole 155. A plurality of front cover fastening holes 184 may be formed corresponding to the number of the board fastening holes 155, and the board fastening members 161 may be coupled to each other.

The rear cover 190 has a rear cover body 191 having a disc shape and penetrates substantially at a central portion of the rear cover body 191 to insert a main body portion 111 of the sensor body 110 into the rear cover 190. The penetrating portion 192 is included. The rear cover fastening hole 194 to which the cover fastening member 162 is coupled is formed at an outer side of the rear cover through part 192. The rear cover 190 may be coupled to the sensor body 110 by the cover fastening member 162.

The front cover 180 and the rear cover 190 may be removed when connected to the power unit 200 or the load unit.

The reinforcement bridge 120 may have a bar shape. In detail, the reinforcing bridge 120 extends radially outward from the main body center portion 111 and may be configured to be coupled to an inner circumferential surface of the main body outer surface portion 112. The reinforcing bridge 120 may be configured to reduce the cross-sectional area from the main body central portion 111 toward the main body outer surface portion 112.

The reinforcement bridge 120 is provided with a plurality, the plurality of reinforcement bridge 120 may each extend radially outward from different points of the central portion 111 of the main body. In one example, the number of the reinforcing bridge 120 may be provided at least three. 4, three reinforcement bridges 120 are shown, but four or more reinforcement bridges 120 may be provided.

The sensing bridge 130 may have a bar shape. In detail, the sensing bridge 120 extends radially outward from the main body center portion 111 and may be configured to be coupled to an inner circumferential surface of the main body outer surface portion 112. The reinforcement bridge 120 may be configured such that its cross-sectional area is constant from the main body center portion 111 toward the main body outer surface portion 112.

A strain gauge 140 may be attached to at least one side of both sides of the sensing bridge 130 based on the radial direction. The strain gauge 140 may be configured to detect the amount of torsion generated between the power unit 200 and a load device (not shown). The load device may be understood as a device located on the opposite side of the power unit 200 based on the torque sensor 100 in FIG. 7.

For example, the strain gauge 140 may be disposed on both side surfaces of the sensing bridge 130. By the arrangement of the strain gauge 140, the strain gauge 140 can easily detect the three-dimensional deformation of the sensing bridge 130, that is, the deformation in three axes (x, y, z axis). .

A plurality of sensing bridges 130 are provided, and each of the plurality of sensing bridges 130 may extend radially outward from different points of the main body 111. For example, the number of the sensing bridges 120 may be provided at least three. 4, three sensing bridges 120 are provided, but four or more sensing bridges 130 may be provided.

The plurality of reinforcing bridges 120 and the plurality of sensing bridges 130 may be alternately disposed in the circumferential direction. That is, any one of the plurality of reinforcement bridges 120 may be located in a space between two nearest sensing bridges 130.

5 is a front view showing the configuration of the sensor body according to the first embodiment of the present invention, Figure 6 is a cross-sectional view taken along the line VI-VI 'of Figure 1, Figure 7 is a first embodiment of the present invention Sectional drawing showing a configuration of a power transmission device including a torque sensor.

5 to 7, the sensor body 110 according to the first embodiment of the present invention includes a body center portion 111 having a substantially cylindrical shape, and is arranged to surround the body center portion 111. A main body outer surface 112 having a shape and a plurality of bridges (120, 130) extending from the outer peripheral surface of the main body central portion 111 toward the inner peripheral surface of the main body outer surface 112.

The plurality of bridges 120 and 130 may include a plurality of reinforcing bridges 120 to reinforce the rigidity of the sensor body 110. The plurality of reinforcement bridges 120 may prevent the sensor body 110 from being easily deformed by an external force other than the torque to be detected.

The plurality of reinforcement bridges 120 may be arranged at equal intervals. For example, as shown in FIG. 5, when three reinforcement bridges 120 are provided, a center angle between the plurality of reinforcement bridges 120 may be 120 degrees.

The width (circumferential direction) of the reinforcement bridge 120 or its cross-sectional area may be reduced based on a direction from the main body central part 111 toward the main body outer surface part 112. For example, the first width w1 of the portion of the reinforcement bridge 120 that is closer to the main body center portion 111 than the main body outer surface portion 112 is the main body outer surface portion 112 than the main body central portion 111. It may be formed larger than the second width (w2) of the portion near.

The reinforcing bridge 120 includes a bridge reinforcing part 126 coupled to the main body outer surface part 112. The bridge reinforcement part 126 may be located outside the portion of the reinforcement bridge 120 where the second width w2 is formed. In order to increase the coupling force between the reinforcing bridge 120 and the main body outer surface 112, the third width w3 of the bridge reinforcing portion 126 may be larger than the second width w2.

The plurality of bridges 120 and 130 may include a plurality of sensing bridges 130 in which a strain gauge 140 for sensing torque is installed. The strain gauge 140 is based on a torque generated in the three-dimensional direction, that is, a rotation moment based on the direction of the axis 212 (see FIG. 7) of the power unit 200 and a radial direction (x, y axis direction). It may be configured to detect the bending moment generated.

In detail, the strain gauge 140 facilitates the torque Tr generated based on the z-axis direction, the first bending moment M1 in the x-axis direction, and the second bending moment M2 in the y-axis direction. Can be detected (see FIGS. 4 and 5).

The plurality of sensing bridges 130 may be arranged at equal intervals. For example, as illustrated in FIG. 5, when three sensing bridges 130 are provided, a center angle between the plurality of sensing bridges 130 may be 120 degrees. The plurality of reinforcement bridges 120 and the plurality of sensing bridges 130 may be alternately arranged in the circumferential direction. By such an arrangement structure, the strength of the torque sensor 100 can be reinforced, and the torque sensitivity can be easily improved.

The width (circumferential direction) width or the cross-sectional area of the sensing bridge 130 may be constant based on a direction from the main body central part 111 toward the main body outer surface part 112. For example, the width of the sensing bridge 130 may be configured as a first width w4. The first width w4 may be smaller than the first to third widths w1, w2, and w3 of the reinforcement bridge 120.

The sensing bridge 130 includes a first sensing bridge reinforcing part 136 coupled to the main body outer surface part 112. The first sensing bridge reinforcement unit 136 may be located at a radially outer side than a portion of the sensing bridge 130 in which the first width w4 is formed (named “sensing bridge body”). In order to increase the coupling force between the sensing bridge 130 and the main body outer surface 112, the second width w5 of the second bridge reinforcement part 136 may be larger than the first width w4. .

The sensing bridge 130 includes a second sensing bridge reinforcing part 137 coupled to the main body 111. The second sensing bridge reinforcing part 137 may be located radially inward from the sensing bridge main body in which the first width w4 is formed. In order to increase the coupling force between the sensing bridge 130 and the main body 111, the third width w6 of the second sensing bridge reinforcing part 137 may be larger than the first width w4. .

The strain gauge 140 includes a first strain gauge 140a disposed on one side of the sensing bridge 130 and a second strain gauge 140b disposed on the other side of the sensing bridge 130. . The one side and the other side may form a side facing each other. As such, a plurality of strain gauges 140 are provided in each sensing bridge 130 to easily detect the torque generated by the torque sensor 100.

The sensor body 110 includes a through hole 114 formed between the reinforcing bridge 120 and the sensing bridge 130. By the through hole 114, the reinforcement bridge 120 and the sensing bridge 130 is not directly coupled to prevent the force transmitted to the reinforcement bridge 120 is transmitted to the sensing bridge 130. Can be.

The torque sensor 100 may be coupled to the power unit 200 for generating a driving force. In detail, one side of the torque sensor 100, the power unit 200 is coupled, the opposite side may be coupled to a load device (not shown). In this case, the front cover 180 or the rear cover 190 provided in the torque sensor 100 may be coupled to the power unit 200 and the load device in a coupled state or a separated state.

The power unit 200 and the torque sensor 100 may be disposed inside the housing 201.

The power device 200 includes a motor 210 that is rotated by the motor driver 215 (mainboard) and a shaft 212 that is rotated by the driving of the motor 210. An outer circumferential surface of the shaft 212 further includes a bearing 230 provided to be in contact with the shaft 212 to guide rotation of the shaft 212. In addition, the power unit 200 may further include an encoder 220 that detects the amount of rotation of the motor 210.

Inside the shaft 212, a cable inserting portion 213 into which a device cable connected to the motor driver 215 is inserted is formed.

The power unit 200 further includes a reducer 250 disposed between the motor 210 and the torque sensor 100 to reduce the rotational speed of the motor 210. The reducer 250 may be coupled to the front portion of the torque sensor 100.

Hereinafter, a second embodiment of the present invention will be described. Since the present embodiment differs only in the configuration of a plurality of bridges compared with the first embodiment, the differences are mainly described. For the same parts as the first embodiment, the description and reference numerals of the first embodiment are used.

8 is a front view showing the configuration of the sensor body according to the second embodiment of the present invention.

Referring to FIG. 8, the sensor main body 510 according to the second embodiment of the present invention includes a main body center portion 511 and a main body outer surface portion arranged to surround the outside of the main body central portion 511 and having a substantially ring shape. 512 and a plurality of bridges 520 and 530 extending from the outer circumferential surface of the main body center portion 511 toward the inner circumferential surface of the main body outer surface portion 512.

The plurality of bridges 520 and 530 may include a plurality of reinforcing bridges 520 to reinforce the rigidity of the sensor body 510. The plurality of reinforcement bridges 520 may prevent the sensor body 510 from being easily deformed by an external force other than the torque to be detected. The description regarding the plurality of reinforcement bridges 520 uses the description of the reinforcement bridges 120 of the first embodiment.

The plurality of bridges 520 and 530 may include a plurality of sensing bridges 530 on which a strain gauge 540 is installed to sense torque. The strain gauge 540 is based on a torque generated in the three-dimensional direction, that is, a rotation moment based on the direction of the axis 212 (see FIG. 7) of the power unit 200 and a radial direction (x, y axis direction). It may be configured to detect the bending moment generated.

In detail, the strain gauge 540 facilitates the torque Tr generated based on the z-axis direction, the first bending moment M1 in the x-axis direction, and the second bending moment M2 in the y-axis direction. Can be detected (see FIGS. 4 and 8).

The plurality of sensing bridges 530 may be arranged at equal intervals. For example, as illustrated in FIG. 5, when three sensing bridges 530 are provided, a center angle between the plurality of sensing bridges 530 may be 120 degrees. The plurality of reinforcement bridges 120 and the plurality of sensing bridges 130 may be alternately arranged in the circumferential direction. By such an arrangement structure, the strength of the torque sensor 100 can be reinforced, and the torque sensitivity can be easily improved.

The sensor main body 510 includes a first through hole 514 formed between the reinforcing bridge 520 and the sensing bridge 530. Since the reinforcement bridge 520 and the sensing bridge 530 are not directly coupled by the first through hole 514, the force transmitted to the reinforcing bridge 520 is transmitted to the sensing bridge 530. You can prevent it.

A second through hole 535 is formed in the sensing bridge 530. The second through hole 535 may be referred to as a "bridge through hole" in terms of securing a degree of freedom for deformation of the sensing bridge 530. In detail, the sensing bridge 530 includes a first coupling part 531 coupled to an outer surface of the main body 511 and two extension parts 533 and 534 extending radially outward from the first coupling part 531. ) Is included.

The two extension parts 533 and 534 may include a first extension part 533 and a second extension part 534 spaced apart from each other in the circumferential direction. The spaced distance between the first and second extension parts 533 and 534 may be formed to gradually increase toward the radially outer side.

The sensing bridge 530 further includes a second coupling part 532 extending radially outward from the two extension parts 533 and 534 and coupled to the main body outer surface part 512.

The circumferential width of the first coupling portion 531 forms a first width w7 based on the direction from the main body central portion 511 toward the main body outer surface portion 512, and the second coupling portion ( The circumferential width of 532 may form a second width w8. The second width w8 may be larger than the first width w7.

The circumferential widths of the first and second extension parts 533 and 534 may form a third width w9 based on a direction from the main body center portion 511 toward the main body outer surface portion 512. The third width w9 may be smaller than the first width w7 or the second width w8.

The second through hole 535 may be defined by the first and second coupling parts 531 and 532 and the first and second extension parts 533 and 534. That is, the second through hole 535 may be understood as an inner space of the first and second coupling parts 531 and 532 and the first and second extension parts 533 and 534. As the second through hole 535 is formed, the sensing bridge 530 may be easily deformed by a force or torque transmitted to the sensing bridge 530, and thus the torque of the strain gauge 540. Sensitivity can be improved.

The strain gauge 540 includes a first strain gauge 540a disposed on an outer surface of the first extension portion 533 and a second strain gauge 540b disposed on an outer surface of the second extension portion 534. Included. The outer surface of the first extension part 533 and the outer surface of the second extension part 534 may form side surfaces facing each other. As such, a plurality of strain gauges 540 are provided in each of the sensing bridges 530 to easily detect the torque generated by the torque sensor 100.

10 is a block diagram illustrating a sensing device according to an embodiment of the present invention.

11 is a front view of a sensor main body for explaining an arrangement of a plurality of strain gauges according to an exemplary embodiment of the present disclosure.

The sensing device according to an embodiment of the present invention may include a plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 and a plurality of detection circuit units 1010, 1020, 1030, 1040, 1050, and 1060. have.

The plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 may be installed in the plurality of sensing bridges 1010, 1030, and 1050.

In detail, the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 may be installed at both sides of each of the plurality of sensing bridges 1010, 1030, and 1050.

Specifically, the first strain gauge 1011 and the second strain gauge 1021 may be installed on both side surfaces 1110a and 1110b of the first sensing bridge 1010, respectively.

In addition, the third strain gauge 1031 and the fourth strain gauge 1041 may be installed on both side surfaces 1130a and 1130b of the second sensing bridge 1030, respectively.

In addition, the fifth strain gauge 1051 and the sixth strain gauge 1061 may be installed on both side surfaces 1150a and 1150b of the third sensing bridge 1050, respectively.

On the other hand, in the second embodiment in which the sensing bridge includes two extensions, one strain gauge 1031 of the two strain gauges 1031 and 1041 installed in one sensing bridge 1130 has two extensions 1132a. , 1132b may be installed on the outer surface of one extension part 1232a, and the other strain gauge 1041 may be installed on the outer surface of the other extension part 1232b.

Meanwhile, hereinafter, the sensing bridge is described as an example of the second embodiment including two extension parts, but is not limited thereto. The sensing device according to the embodiment of the present invention may also be applied to the first embodiment.

The resistance values of the resistors included in the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 respectively correspond to the torque applied to the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061. Can change in proportion.

Meanwhile, the plurality of detection circuit units 1010, 1020, 1030, 1040, 1050, and 1060 may detect changes in resistance of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061, respectively.

This will be described with reference to FIG. 12 together.

FIG. 12 is a diagram illustrating a first detection circuit unit 1010 connected to a first strain gauge 1011 according to an exemplary embodiment of the present invention.

The first strain gauge 1011 may be connected to the first detection circuit unit 1010.

In addition, the first strain gauge 1011 may include a resistor 1211, and the resistor 1211 included in the first strain gauge 1011 constitutes a resistance of the bridge circuit included in the first detection circuit unit 1010. can do.

Specifically, in order to measure a change in resistance of the strain gauge, the first detection circuit unit 1010 may include a bridge circuit, for example, a Wheatstone bridge circuit.

Also, the bridge circuit may include three resistors Ra, Rb, and Rc not included in the strain gauge, and a resistor 1211 included in the first strain gauge 1011.

Meanwhile, the first detection circuit unit 1010 outputs a signal indicating the resistance value of the resistor 1211 included in the first strain gauge 1011 to the control unit 1090, and the control unit 1090 receives the first detection circuit unit 1010. The torque applied to the first strain gauge 1011 may be calculated based on the signal received from the.

Specifically, the controller 1090 may include the input voltage Vex of the bridge circuit, the resistance values Ra, Rb, and Rc of three resistors not included in the strain gauge, and the first detection circuit unit 1010 when no torque is applied. The resistance value RG1 of the resistor 1211 included in the know is known. Therefore, the controller 1090 calculates the resistance change amount ΔR1 of the resistor 1211 included in the first strain gauge 1011 using the output voltage Vo of the bridge circuit, and based on the resistance change amount ΔR1, The torque applied to one strain gauge 1011 can be calculated.

Meanwhile, the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 may be connected to the plurality of detection circuit units 1010, 1020, 1030, 1040, 1050, and 1060 one-to-one. In addition, the description of the first strain gauge 1011 and the first detection circuit unit 1010 described in FIG. 12 may be applied to other strain gauges and other detection circuit units.

For example, the second strain gauge 1021 is connected to the second detection circuit unit 1020, and the resistance included in the second strain gauge 1021 is a resistance of the bridge circuit included in the second detection circuit unit 1020. Can be configured. In addition, the controller 1090 may calculate a resistance change amount of the resistance included in the second strain gauge 1021 and a torque applied to the second strain gauge 1021 based on the output voltage output from the second detection circuit unit 1020. Can be.

For another example, the sixth strain gauge 1061 is connected to the sixth detection circuit unit 1060, and the resistance included in the sixth strain gauge 1061 is a resistance of the bridge circuit included in the sixth detection circuit unit 1060. Can be configured. Also, the controller 1090 may calculate a resistance change amount of the resistance included in the sixth strain gauge 1061 and a torque applied to the sixth strain gauge 1061 based on the output voltage output from the sixth detection circuit unit 1060. Can be.

In this manner, the controller 1090 controls the resistance change amount of each of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 and the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061, respectively. The torque applied to can be calculated.

The controller 1090 may be used interchangeably with terms such as a central processing unit, a microprocessor, and a processor.

Meanwhile, the controller 1090 is based on a change in resistance of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 respectively detected by the plurality of detection circuit units 1010, 1020, 1030, 1040, 1050, and 1060. Thus, a rotation moment based on the direction of the axis 212 (see FIG. 7) of the power unit 200 and a bending moment based on the radial direction may be determined.

A method of determining the rotation moment based on the axial direction will be described in detail with reference to FIGS. 13 to 16 and a method of determining the bending moment based on the radial direction.

FIG. 13 is a diagram for describing a method of determining a rotation moment when a rotation moment is generated based on an axial direction, that is, a Z axis direction, according to an embodiment of the present disclosure.

The controller 1090 may increase resistance of the strain gauges installed on the first side of each of the plurality of sensing bridges 1010, 1030, and 1050, and may be installed on the second side of each of the plurality of sensing bridges 1010, 1030, and 1050. If the resistance of the strain gauges decreases, it can be determined that a rotational moment relative to the axial direction is applied.

Specifically, the direction of vertically penetrating the ground on which the drawing is shown on the drawing may be the direction of the Z axis. When the sensor body rotates based on the Z-axis direction, the resistances of the strain gauges installed on the first side surfaces of each of the plurality of sensing bridges 1010, 1030, and 1050 increase, and the plurality of sensing bridges 1010, 1030, and 1050 increase. The resistance of the strain gauges installed on each second side can be reduced.

For example, when the sensor main body rotates in the clockwise direction CW, the displacement of the left side surface of each of the plurality of sensing bridges 1010, 1030, and 1050 is increased, and each of the plurality of sensing bridges 1010, 1030, and 1050 is increased. The displacement of the right side can be reduced.

In this case, the displacement of the strain gauges 1011, 1031, and 1051 installed on the left side of each of the plurality of sensing bridges 1010, 1030, and 1050 may increase, and the resistance may decrease. In addition, the displacement of the strain gauges 1021, 1041, and 1061 installed on the right side of each of the sensing bridges 1010, 1030, and 1050 may decrease, and the resistance may increase.

On the contrary, when the sensor main body rotates in the counterclockwise direction (CCW), the displacement of the left side of each of the plurality of sensing bridges 1010, 1030, 1050 decreases, and each of the plurality of sensing bridges 1010, 1030, 1050 is reduced. The displacement of the right side can increase.

In this case, the displacement of the strain gauges 1011, 1031, and 1051 installed on the left side of each of the plurality of sensing bridges 1010, 1030, and 1050 may decrease, and the resistance may increase. In addition, the displacement of the strain gauges 1021, 1041 and 1061 installed on the right side of each of the plurality of sensing bridges 1010, 1030 and 1050 may increase and the resistance may decrease.

An example of the strain gauge strain when there is a rotation about the Z axis is as follows.

direction Item Left side
Strain gauge Right side
Strain gauge

CW


Displacement
(mm)
First Sense Bridge 1110 3.00297 2.99689 Second sensing bridge 1130 3.00300 2.99690 Third Sense Bridge 1150 3.00303 2.99693 Average 3.00301 2.99693 Displacement Rate (%) 0.100 -0.102

CCW


Displacement
(mm)
First Sense Bridge 1110 2.99706 3.00298 Second sensing bridge 1130 2.99703 3.00310 Third Sense Bridge 1150 2.99700 3.00311 Average 2.99703 3.00307 Displacement Rate (%) -0.099 0.102

That is, the controller 1090 may increase resistance of the strain gauges installed on the first side surfaces of each of the plurality of sensing bridges 1010, 1030, and 1050, and increase the resistance of the strain gauges on the second side surfaces of each of the plurality of sensing bridges 1010, 1030, and 1050. If the resistance of the installed strain gages decreases, it can be determined that a rotational moment relative to the axial direction is applied.

In addition, the controller 1090 decreases the resistance of the strain gauges 1011, 1031, and 1051 provided on the left side of each of the plurality of sensing bridges 1010, 1030, and 1050, and reduces the resistance of the plurality of sensing bridges 1010, 1030, and 1050. When the resistance of the strain gauges 1021, 1041, 1061 provided on each right side increases, it can be determined that the sensor main body rotates in the clockwise direction CW.

In addition, the control unit 1090, the resistance of the strain gauge (1011, 1031, 1051) provided on the left side of each of the plurality of sensing bridge (1010, 1030, 1050) increases, the plurality of sensing bridge (1010, 1030, 1050) When the resistance of the strain gauges 1021, 1041, 1061 provided on each right side decreases, it can be determined that the sensor body rotates in the counterclockwise direction (CCW).

Also, the controller 1090 may calculate the magnitude of the rotation moment based on the Z axis based on the resistances of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061.

The controller 1190 is configured to increase or decrease the resistance of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 detected by the plurality of detection circuit units 1010, 1020, 1030, 1040, 1050, and 1060, respectively. And the direction of the bending moment applied to the sensor body based on at least one of the increase and decrease amounts.

Various embodiments related to this will be described with reference to FIGS. 14 to 16.

FIG. 14 is a diagram illustrating a case where a torque based on the Y axis direction, that is, a bending moment based on the Y axis direction is generated.

When an external force is applied to the point on the first line 1410 of the sensor body in the Z-axis direction (or -Z-axis direction), an example of the deformation amount of the strain gauge is as follows.

division Displacement (mm) % Displacement First Sense Bridge 1110
First strain gauge 1011 2.99969 -0.010 Second strain gauge 1021 2.99964 -0.012 Second sensing bridge 1130
Third strain gauge 1031 3.00029 0.010 Fourth Strain Gage 1041 3.00010 0.003 Third Sense Bridge 1150
Fifth Strain Gage 1051 3.00009 0.003 Sixth Strain Gage 1051 3.00030 0.010

When an external force is applied to the point on the first line 1410 of the sensor main body in the Z-axis direction (or -Z-axis direction), it is located on the radial direction (XY plane) and is based on the direction perpendicular to the first line 1410. A bending moment may occur.

The controller 1090 may increase or decrease the resistance of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 detected by the plurality of detection circuit units 1010, 1020, 1030, 1040, 1050, and 1060, respectively. And a direction of the bending moment generated by the force acting on the first line 1410 based on at least one of the increase and decrease amounts.

For example, a third sensing bridge facing the resistance of the fourth strain gauge 1041 installed on one side 1130b of the second sensing bridge 1130 and one side 1130b of the second sensing bridge 1130 ( When the resistance of the fifth strain gage 1051 provided on one side 1150a of the 1150 is equally reduced, the controller 1090 may have a Z-axis direction (or -Z-axis direction) at a point on the first line 1410. It can be determined that the force worked. In this case, the first line 1410 forms an acute angle with the second sensing bridge 1130 and the third sensing bridge 1150, and the angle θ2 between the first line 1410 and the second sensing bridge 1130 is The angle θ1 formed by the first line 1410 and the third sensing bridge 1150 may be the same.

In addition, the controller 1090 may determine that a bending moment M3 is generated based on the Y-axis direction positioned on the radial direction (XY plane) and perpendicular to the first line 1410.

In another embodiment, it is also possible to determine using a strain gauge other than the fourth strain gauge 1041 and the second sensing bridge 1130.

For example, the resistance of the first strain gauge 1011 installed at one side 1110a of the first sense bridge 1110 and the second strain gauge 1021 provided at the other side 1110b of the first sense bridge 1110. If the resistance of) increases equally, the controller 1090 determines that the Z-axis direction (or -Z-axis direction) force is applied to the point on the first line 1410, and bending based on the Y-axis direction. It can be determined that the moment M3 has occurred.

For another example, when the resistance of the third strain gauge 1031 and the resistance of the sixth strain gauge 1061 are equally reduced, the controller 1090 may be connected to the Z-axis direction (the point on the first line 1410). Or -Z axis direction) force, and it can be determined that a bending moment M3 based on the Y axis direction has occurred.

In this manner, in the situation as shown in FIG. 14, the direction of the bending moment may be determined using only resistance values of some of the plurality of strain gauges, but in actual implementation, the direction of the bending moment may be used by using the resistance values of all of the plurality of strain gauges. Determining this will minimize the error.

In addition, the controller 1090 may calculate the magnitude of the bending moment M3 using the resistance of some or all of the plurality of strain gauges.

FIG. 15 is a diagram illustrating a case in which a torque based on a 60 degree direction from the Y axis, that is, a bending moment based on a 60 degree direction from the Y axis occurs.

When the external force is applied to the point on the second line 1510 of the sensor main body in the Z-axis direction (or -Z-axis direction), an example of the deformation amount of the strain gauge is as follows.

division Displacement (mm) % Displacement First Sense Bridge 1110
First strain gauge 1011 2.99973 -0.009 Second strain gauge 1021 2.99991 -0.003 Second sensing bridge 1130
Third strain gauge 1031 2.99999 -0.000 Fourth Strain Gage 1041 2.99971 -0.010 Third Sense Bridge 1150
Fifth Strain Gage 1051 3.00039 0.013 Sixth Strain Gage 1051 3.00036 0.012

When an external force is applied to the point on the second line 1510 of the sensor body in the Z axis direction (or -Z axis direction), it is located on the radial direction (XY plane) and is based on the direction perpendicular to the second line 1510. A bending moment may occur.

The controller 1090 may increase or decrease the resistance of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 detected by the plurality of detection circuit units 1010, 1020, 1030, 1040, 1050, and 1060, respectively. And a direction of the bending moment generated by the force acting on the second line 1510 based on at least one of the increase and decrease amounts.

For example, the resistance of the fifth strain gauge 1051 installed on one side of the third sensing bridge 1150 and the resistance of the sixth strain gauge 1061 provided on the other side of the third sensing bridge 1150 are the same. When decreasing, the controller 1090 may determine that the Z-axis direction (or -Z-axis direction) force is applied to the point on the second line 1510. In this case, the second line 1510 forms an acute angle with one side of the third sensing bridge 1150 and the other side of the third sensing bridge 1150, and the second line 1510 and the third sensing bridge 1150 of the third sensing bridge 1150. The angle θ4 of one side may be the same as the angle θ3 between the second line 1510 and the other side of the third sensing bridge.

In addition, the controller 1090 may determine that a bending moment M4 is generated based on a specific axis positioned on the radial direction (XY plane) and perpendicular to the second line 1510.

As another example, when the resistance of the first strain gauge 1011 and the resistance of the fourth strain gauge 1041 are equally increased, the controller 1090 may control the Z axis direction (or −) at a point on the second line 1510. Z-axis direction) force is determined, it can be determined that the bending moment (M4) based on the specific axis has occurred.

As another example, when the resistance of the second strain gauge 1021 and the resistance of the third strain gauge 1031 are equally increased, the controller 1090 may move in the Z-axis direction (or at a point on the second line 1510). -Z-axis direction) force can be determined, it can be determined that the bending moment (M4) based on the specific axis has occurred.

Also, in actual implementation, the controller may minimize the error by determining the direction of the bending moment by using the resistance values of all the plurality of strain gauges.

In addition, the controller 1090 may calculate the magnitude of the bending moment M4 using the resistance of some or all of the plurality of strain gauges.

16 is a diagram illustrating a case in which a torque based on a 30 degree direction from the Y axis, that is, a bending moment based on a 30 degree direction from the Y axis occurs.

When an external force is applied to the point on the third line 1610 of the sensor body in the Z-axis direction (or -Z-axis direction), an example of the deformation amount of the strain gauge is as follows.

division Displacement (mm) % Displacement First Sense Bridge 1110
First strain gauge 1011 2.99966 -0.011 Second strain gauge 1021 2.99974 -0.009 Second sensing bridge 1130
Third strain gauge 1031 3.00015 0.005 Fourth Strain Gage 1041 2.99989 -0.004 Third Sense Bridge 1150
Fifth Strain Gage 1051 3.00028 0.009 Sixth Strain Gage 1051 3.00038 0.013

When an external force is applied to the point on the third line 1610 of the sensor main body in the Z-axis direction (or -Z-axis direction), it is impossible to determine the direction of the bending moment in the manner described with reference to FIGS. 14 and 15.

In this case, the controller 1090 increases or decreases the resistance of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 detected by the plurality of detection circuit units 1010, 1020, 1030, 1040, 1050, and 1060, respectively. And the amount of increase and decrease, the direction and magnitude of the bending moment M5 generated by the force acting on the third line 1610 may be calculated. In this case, a specific method of calculating the direction and size of the bending moment M5 may vary depending on the characteristics of the strain gauge and the sensor body.

FIG. 17 is a front view of a sensor main body for explaining an arrangement of a plurality of strain gauges, according to another exemplary embodiment.

Although an embodiment in which three sensing bridges and six strain gauges have been described above is not limited thereto, the number of sensing bridges and strain gauges may be variously changed.

For example, as shown in FIG. 17, the sensing device according to an embodiment of the present invention includes four sensing bridges 1710, 1730, 1750, and 1830 and four sensing bridges 1710, 1730, 1750, and 1830. Eight strain gauges (1011, 1021, 1031, 1041, 1051, 1061, 1071, 1081) installed on the side may be included.

In addition, eight strain gauges 1011, 1021, 1031, 1041, 1051, 1061, 1071, and 1081 may be connected one-to-one with eight detection circuit units.

The direction and size of the bending moment may be determined according to the various methods described above.

For example, the resistances of the fifth strain gauge 1051 and the sixth strain gauge 1061 are equally reduced, and the resistances of the fourth strain gauge 1041 and the seventh strain gauge 1071 are equally reduced, When the resistances of the third strain gauge 1031 and the eighth strain gauge 1081 are equally increased, and the resistances of the first strain gauge 1011 and the second strain gauge 1021 are equally increased, the controller 1090. It may be determined that the bending moment M6 in the X-axis direction is generated by the force acting on the fourth line 1810.

In another example, the resistances of the sixth strain gauge 1061 and the seventh strain gauge 1071 are equally reduced, and the resistances of the fifth strain gauge 1051 and the eighth strain gauge 1081 are equally reduced. When the resistance of the first strain gauge 1011 and the fourth strain gauge 1041 increases equally, and the resistance of the second strain gauge 1021 and the third strain gauge 1031 increases equally, the controller 1090 ) May determine that the bending moment M7 in the first axial direction is generated by the force acting on the fifth line 1820.

In another example, the resistances of the eighth strain gauge 1081 and the seventh strain gauge 1071 are equally reduced, and the resistances of the first strain gauge 1011 and the sixth strain gauge 1061 are equally reduced. When the resistances of the second strain gauge 1021 and the fifth strain gauge 1051 are equally increased, and the resistances of the third strain gauge 1031 and the fourth strain gauge 1041 are equally increased, the controller ( 1090 may determine that the bending moment M8 in the X-axis direction is generated by the force acting on the sixth line 1830.

As described above, the present invention can independently measure the resistance change of each strain gauge by connecting the resistances of the plurality of strain gauges to the plurality of detection circuits one-to-one. Therefore, calibration by bending moment, linear correction, temperature correction, sensitivity correction, and the like can be easily and accurately performed, and there is an advantage in that torque can be measured even when any strain gauge fails.

For example, the basic resistance value of strain gauges has a rate of change with temperature. Therefore, in the conventional method of configuring one bridge circuit using a plurality of strain gauges, the offset resistance is generally adjusted by adjusting the basic resistance values of the plurality of strain gauges to be equal to zero. In this case, however, the resistances of the plurality of strain gauges do not operate independently of each other, and all of the resistances of the plurality of strain gauges affect the output voltage Vo. In other words, the output value from the bridge circuit is only one (output voltage), but since the factors that can affect the output voltage values are the basic resistance values of all strain gauges, accurate calibration is very difficult.

However, according to the present invention, the value output from each of the detection circuit units 1010, 1020, 1030, 1040, 1050, and 1060 is one (output voltage), and each of the factors that may affect the output voltage value (the corresponding Resistance of the strain gauge).

Therefore, the basic resistance values of each of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 are accurately calculated, and the basic resistance values of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 are calculated. The same can be adjusted. This has the advantage of allowing accurate and quick calibration.

In addition, the resistance change value of each of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 may indicate the sensitivity of the sensor. Then, a process of matching the sensitivity of each of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 is required. However, in the conventional configuration of a bridge circuit using a plurality of strain gauges, the resistances of the plurality of strain gauges do not operate independently of each other, and all of the resistance change values of the plurality of strain gauges affect the output voltage Vo. As a result, a problem may occur in which accurate sensitivity correction is very difficult.

However, according to the present invention, the resistance change value of each of the plurality of strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 is independently calculated, and the strain gauges 1011, 1021, 1031, 1041, 1051, and 1061 are respectively calculated. The resistance change can be adjusted to match (ie, to match sensitivity). Accordingly, there is an advantage that accurate and fast sensitivity correction is possible.

In addition, the present invention, when a plurality of strain gauges are installed on the side for the measurement of the rotation moment, because the bending moment is measured by combining the values measured in the same strain gauge, it is possible to improve the accuracy of the measurement and reduce the cost There is an advantage.

In addition, even when a bending moment occurs due to a force acting on a line without a strain gage on the XY plane, by measuring the values measured in the plurality of strain gages together, the exact direction and size of the bending moment can be measured. There is an advantage.

Also, the sensing device basically measures the rotation moment based on the Z-axis direction, but when the bending moment occurs together, the sensing device cannot measure the accurate rotation moment. However, since the present invention blocks the interaction between the strain gauges by measuring the resistance change of each strain gauge independently, it is possible to accurately measure the bending moment and to easily correct the rotation moment by the influence of the bending moment. There is an advantage.

The present invention described above can be embodied as computer readable codes on a medium in which a program is recorded. The computer-readable medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable media include hard disk drives (HDDs), solid state disks (SSDs), silicon disk drives (SDDs), ROMs, RAM, CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, and the like. There is this. The foregoing detailed description should not be construed as limiting in all respects, but should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

1011, 1021, 1031, 1041, 1051, 1061: strain gauge

Claims (8)

A sensor body including a main body portion, a main body outer surface portion disposed to surround the outside of the main body portion, and a plurality of sensing bridges extending from the outer surface of the main body portion toward the inner surface of the main body outer surface portion;
A plurality of strain gauges installed in the plurality of sensing bridges; And
Includes; a plurality of detection circuit unit for detecting a change in the resistance of the plurality of strain gauges,
The plurality of strain gauges,
Connected one-to-one with the plurality of detection circuits,
Sensing device. The method of claim 1,
The resistance of each of the plurality of strain gauges,
Constituting the resistance of the bridge circuit connected one-to-one
Sensing device. The method of claim 1,
The plurality of strain gauges,
Installed on both sides of each of the plurality of sensing bridges.
Sensing device. The method of claim 3, wherein
And a controller configured to determine at least one of a rotation moment based on an axial direction and a bending moment based on a radial direction based on a change in resistance of the plurality of strain gauges respectively detected by the plurality of detection circuit units. doing
Sensing device. The method of claim 4, wherein
The control unit,
When the resistance of the strain gauges installed on the first side of each of the plurality of sensing bridges increases and the resistance of the strain gauges installed on the second side of each of the plurality of sensing bridges decreases, the rotation moment relative to the axial direction of the power unit To determine that the
Sensing device. The method of claim 4, wherein
The control unit,
The direction of the bending moment applied to the sensor main body is determined based on at least one of the increase and decrease of the resistance and the increase and decrease of the resistance of the plurality of strain gauges respectively detected by the plurality of detection circuit units.
Sensing device. The method of claim 6,
The control unit,
If the resistance of the first strain gauge provided on one side of the first sensing bridge and the resistance of the second strain gauge provided on one side of the second sensing bridge facing the side of the first sensing bridge are equally reduced, the first Determine the direction of bending moment generated by the force acting on the line,
The first line forms an acute angle with the first sensing bridge and the second sensing bridge,
An angle between the first line and the first sensing bridge is equal to an angle between the first line and the second sensing bridge.
Sensing device. The method of claim 6,
The control unit,
When the resistance of the third strain gauge provided on one side of the first sensing bridge and the resistance of the fourth strain gauge provided on the other side of the first sensing bridge are equally reduced, bending caused by a force acting on the second line Determine the direction of the moment,
The second line forms an acute angle with one side of the first sensing bridge and the other side of the first sensing bridge,
An angle between the second line and one side of the first sensing bridge is equal to an angle between the second line and the other side of the first sensing bridge.
Sensing device.

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