KR20200143610A - Force sensor and multiaxial force/torque sensor using the same - Google Patents

Abstract

The present invention relates to a force sensor and a multiaxial force and torque sensor using the same. According to the present invention, the force sensor comprises: a ground portion, as a grounded conductor of which the position is changed by an external force, including a flat plate module having a flat plate shape and an insertion module formed on a lower surface of the flat plate module to protrude in a cylindrical shape; a substrate portion which has a flat plate shape, is spaced apart from the flat plate module, and has a circular hole into which the insertion module can be inserted while being spaced apart from the substrate portion; electrode portions which are formed on the sides of the hole and at the edge of the hole formed in the upper surface of the substrate portion and receive power to form a capacitance together with the ground portion; and a force measurement portion for calculating a vertical force or a horizontal force applied to the ground portion by using the capacitance.

Description

Force sensor and multi-axis force and torque sensor using the same {FORCE SENSOR AND MULTIAXIAL FORCE/TORQUE SENSOR USING THE SAME}

The present invention relates to a force sensor and a multiaxial force and torque sensor using the same. More specifically, it relates to a force sensor that uses the value of capacitance, is simple to assemble, and enables precise external force measurement, and a multiaxial force and torque sensor using the same.

Mechanical devices such as industrial robots are equipped with sensors for measuring force or torque applied during work. At this time, since forces and torques are applied to the mechanical device in various directions and affect the operation of the mechanical device, a sensor capable of measuring such force and torque is required for accurate control of the mechanical device.

Korean Patent Registration No. 10-1470160 relates to a flat plate type force/torque sensor capable of measuring forces and torques in various directions. When an external force is applied perpendicularly to the sensor cell, the distance between the first electrode and the second electrode is increased. As it decreases, the capacitance (capacitance) value increases, and when an external force is applied horizontally to the sensor cell, the opposing area between the first electrode and the second electrode decreases, and the vertical and horizontal drag are controlled using the principle that the capacitance value decreases. A sensor capable of measuring has been disclosed.

However, in the case of the electrode structure as described above, the capacitance value varies according to the change in the distance between the electrodes, but the capacitance value according to the change in the opposing area is not large, so it is difficult to accurately measure the horizontal drag.

Thus, as shown in FIG. 1, the plate-shaped first electrode 10 is inserted into the groove formed in the substrate S, and the second electrode 20 is formed on the substrate S to form the first electrode 10. When a horizontal shear force is applied to ), the sensor sensitivity can be improved by measuring the capacitance value according to the change in the distance between the two electrodes 10 and 20. However, it is difficult to install the plate-shaped first electrode 10 so as to be spaced apart from each other at a predetermined interval between grooves formed in the substrate S. In particular, in order to implement a multi-axial force and torque sensor, a plurality of sensor configurations as shown in Fig. 1 must be arranged. In each sensor configuration, a certain distance between the plate-shaped first electrode 10 and the groove of the substrate S There was a difficulty in assembling the sensor so as to keep it at the same time.

Korean Patent Registration No. 10-1470160

Accordingly, an object of the present invention is to solve such a conventional problem, and by forming an electrode in a circular hole and forming a cylindrical earth electrode inserted into the hole, the assembly is simple and the measurement accuracy of the sensor is improved. It is to provide a force sensor that can be used.

In addition, by forming electrodes in a plurality of circular holes and forming a cylindrical earth electrode inserted into the holes, it is intended to provide a multi-axial force and torque sensor that can be easily assembled and improve the measurement accuracy of the sensor.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

The above object is, according to the present invention, as a grounded conductor whose position is changed by an external force, the ground portion including a flat plate module and an insertion module protruding in a cylindrical shape on a lower surface of the flat panel; A plate-shaped substrate, which is formed to be spaced apart from the plate module, and has a circular hole through which the insertion module can be inserted; An electrode formed on a side surface of the hole and an edge of the hole on an upper surface of the substrate, the electrode portion receiving power and forming a capacitance together with the ground portion; And it may be achieved by a force sensor including a force measuring unit for obtaining a force in a vertical direction or a force in a horizontal direction applied to the ground unit using the capacitance value.

Here, the electrodes formed on the side of the hole and the edge of the hole on the upper surface of the substrate may be integrally formed.

Here, the electrode portion may be separately formed along the circumferential direction of the hole.

Here, the electrode portion may be equally divided into two or more along the circumferential direction of the hole.

Here, a dielectric may be formed in a space between the flat panel module and the substrate and a space between the hole and the insertion module.

Here, the dielectric may be at least one of a polymer, air, and water.

The above object is, according to the present invention, comprises three or more force sensors and a calculation unit for obtaining a multi-axial force and torque acting on the force sensor, the force sensor is a force sensor of any one of the aforementioned force sensors, the The calculation unit may be achieved by a multiaxial force and torque sensor that calculates a multiaxial force and a multiaxial torque using the vertical and horizontal forces measured by the three or more force sensors.

Here, the three or more force sensors are disposed on the same plane, and may be disposed to be spaced apart from each other at the same distance on the same circumference.

The above object is, according to the present invention, a grounded conductor whose position is changed by an external force, including a flat plate module and a cylindrical insertion module protruding from a lower surface of the flat module at least three part; A substrate in the form of a flat plate, which is formed to be spaced apart from the flat module, and has a plurality of circular holes through which three or more insertion modules can be inserted therefrom; A plurality of electrode portions formed on a side surface of the hole and an edge of a hole on an upper surface of the substrate portion for the plurality of holes, the electrode portions forming a capacitance together with the ground portion by receiving power; For each of the plurality of electrode units, a force measuring unit for measuring a force in a vertical direction or a force in a horizontal direction applied to the ground unit by using the capacitance value; And a multiaxial force and torque sensor including a calculation unit that calculates a multiaxial force and a multiaxial torque applied to the ground by using the vertical force and the horizontal force measured by the force measuring unit.

Here, the electrodes formed on the side of the hole and the edge of the hole on the upper surface of the substrate may be integrally formed.

Here, the electrode portion may be separately formed along the circumferential direction of the hole.

Here, the electrode portion may be equally divided into two or more along the circumferential direction of the hole.

Here, a dielectric may be formed in a space between the flat panel module and the substrate and a space between the hole and the insertion module.

Here, the dielectric may be at least one of a polymer, air, and water.

Here, the insertion module and the hole may be disposed to be spaced apart from each other at the same distance on the same circumference.

According to the force sensor of the present invention and a multiaxial force and torque sensor using the same as described above, since a gap is formed by inserting a cylindrical earth electrode of a smaller diameter into a circular hole in which an electrode is formed on the substrate, the size and center of the circle There is an advantage that it is easy to assemble the sensor since it is possible to form a gap if it is aligned.

In addition, since the electrode formed on the side of the circular hole and the cylindrical earth electrode are arranged spaced apart in a curved shape, the sensing cross-sectional area can be increased compared to the case where the two plates are spaced apart in a plane, thereby improving the sensitivity of the sensor. There is also an advantage of being able to do it.

1 is a diagram illustrating a structure in which a capacitance value according to a change in distance between two electrodes is measured when a horizontal shear force is applied in the related art.
2 is a cross-sectional view showing the structure of a force sensor according to an embodiment of the present invention.
3 is an enlarged perspective view illustrating an electrode portion formed in a circular hole of a substrate portion in FIG. 2.
FIG. 4 is a cross-sectional view showing the movement of a ground portion when a normal force is applied in the force sensor of FIG. 2.
FIG. 5 is a cross-sectional view showing a movement of a ground portion when a normal force is applied at a position different from that of FIG. 4 in the force sensor of FIG. 2.
6 is a cross-sectional view showing a movement of a ground portion when a horizontal force is applied in the force sensor of FIG. 2.
7 is an exploded perspective view of a multiaxial force and torque sensor according to an embodiment of the present invention.
8 is a combined perspective view of FIG. 7.

Specific details of the embodiments are included in the detailed description and drawings.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, and only these embodiments make the disclosure of the present invention complete, and are common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

Hereinafter, the present invention will be described with reference to the drawings for explaining a force sensor and a multiaxial force and torque sensor using the same according to embodiments of the present invention.

2 is a cross-sectional view showing the structure of a force sensor according to an embodiment of the present invention, FIG. 3 is an enlarged perspective view showing an electrode portion formed in a circular hole of the substrate portion in FIG. 2, and FIG. 4 is a force of FIG. A cross-sectional view showing the movement of the ground portion when a normal force is applied in the sensor, and FIG. 5 is a cross-sectional view of the ground portion when a normal force is applied at a position different from that of FIG. 4 in the force sensor of FIG. It is a cross-sectional view showing movement, and FIG. 6 is a cross-sectional view showing movement of a ground portion when a horizontal force is applied in the force sensor of FIG. 2.

As shown in FIG. 2, the force sensor 100 according to an embodiment of the present invention is a sensor for measuring a normal force and a shear force in a horizontal direction, and the ground portion 110 ), a substrate portion 120, an electrode portion 130, and a force measuring portion (not shown).

When the ground unit 110 receives an external force, the position of the ground unit 110 changes accordingly. Although not shown, an elastic body such as a plurality of springs is formed on the bottom surface of the ground unit 110 so that when a force is applied to the upper surface, the ground unit 110 can move its position, and when the external force is removed, the elastic force It can be configured so that the position can be restored again.

The ground portion 110 is formed of a grounded conductor, and a capacitance is formed by the electrode portion 130 to be described later, and the dielectric 140 formed between the ground portion 110 and the electrode portion 130.

As shown, the ground unit 110 may include a flat plate module 112 in a flat plate shape and an insertion module 114 protruding in a cylindrical shape on a lower surface of the flat plate module 112. At this time, the flat plate module 112 is horizontally disposed to be spaced apart from the substrate unit 120 to be described later by a predetermined distance, and the insertion module 114 is inserted to be spaced apart from the side of the hole 122 formed in the substrate unit 120 Is placed.

The substrate unit 120 is a flat substrate and may be configured as, for example, a printed circuit board (PCB). As shown in FIG. 2, the substrate unit 120 is disposed in parallel to be spaced apart from the flat panel module 112 of the ground unit 110 by a predetermined distance. When a force is applied in the vertical downward direction from the upper surface of the flat panel module 112, the distance between the flat panel module 112 and the substrate unit 120 may be changed. At this time, even if an external force is applied, the substrate unit 120 and the flat panel module ( 112) It is preferable to arrange so as not to contact between.

In addition, a circular hole 122 is formed in the substrate portion 120, and the insertion module 114 of the ground portion 110 is inserted into the hole 122. At this time, the side surface of the hole 122 and the outer surface of the insertion module 114 are arranged to be spaced apart from each other so that when a force is applied to the ground part 110 in the horizontal direction, the side surface of the hole 122 and the insertion module 114 The distance may be changed, and at this time, even if an external force is applied, it is preferable to arrange the side surface of the hole 122 and the insertion module 114 not to contact each other.

In this case, as illustrated in FIGS. 2 and 3, an electrode unit 130 integrally formed may be formed at the side of the hole 122 and at the edge of the hole 122 on the upper surface of the substrate unit 120. That is, the plating conductive hole for connecting the layers between the upper layer and the lower layer without inserting a component into the PCB substrate is called a via hole (Via_Hole), and the electrode unit 130 cannot be formed in the substrate unit 120 in the form of a via hole. have. In the drawing of FIG. 2, an electrode is also formed on the lower surface of the substrate unit 120, so that the cross-sectional shape of the entire electrode unit 130 has a'c' shape, but the electrode must be formed on the lower surface of the substrate unit 120 It doesn't have to be.

For convenience of explanation, the electrode part 130 formed on the side of the hole 122 is the side electrode part 131, and the electrode part 130 formed at the edge of the hole 122 of the upper surface of the substrate part 120 is the top surface. It is referred to as the electrode part 132 and will be described later. As described above, the side electrode part 131 and the upper electrode part 132 are not electrically separated and may be integrally formed. When power is applied to the electrode unit 130, a capacitance is formed between the side electrode unit 131 and the insertion module 114 formed adjacent to each other, and the electrostatic capacity is formed between the upper electrode unit 132 and the flat panel module 112. To form a capacity.

In this case, the electrode part 130 may be formed separately into a first electrode part 130a and a second electrode part 130b along the circumferential direction of the hole 122 as shown in FIG. 3, and preferably It can be bisected. In the present embodiment, the description is mainly divided into two, but the description is not limited thereto and may be divided into a larger number and separated.

In this way, the first electrode unit 130a and the second electrode unit 130b are physically and electrically separated, and the capacitance is measured for the first electrode unit 130a and the second electrode unit 130b, respectively. , The force in the vertical direction and the force in the horizontal direction applied to the ground part 110 are measured using values of capacitance measured by the first electrode part 130a and the second electrode part 130b.

A dielectric 140 may be formed in a space between the flat panel module 112 and the substrate 120 and a space between the hole 122 and the insertion module 114, and the dielectric 140 includes a polymer, air And water may be formed, but is not limited thereto.

The force measurement unit (not shown) is a calculation device formed on the substrate unit 120, and measures the value of the capacitance formed between the electrode unit 130 and the ground unit 110 when an external force is applied to the ground unit 110. The vertical force or horizontal force applied to the ground unit 110 is obtained by using. Preferably, a capacitance value applied to the first electrode portion 130a and a capacitance value applied to the second electrode portion 130b are obtained, respectively, and a vertical force or a horizontal force applied to the ground portion 110 is calculated therefrom. do.

The capacitance value between the two electrodes 110 and 130 sandwiching the dielectric 140 is inversely proportional to the distance between the two electrodes 110 and 130. As shown in FIG. 4, when the ground part 110 moves downward by the force in the vertical direction, the distance between the upper electrode part 132 and the flat panel module 112 decreases, thereby increasing the capacitance value. do.

At this time, when a force is applied to the center of the ground unit 110 as shown in FIG. 4 to move downward while the flat panel module 112 remains horizontal, the first electrode unit 130a and the second electrode unit ( In 130b), since the distances d _1N and d _{2N to the} flat panel modules 112 are the same, the measured capacitance values are all the same.

However, as shown in FIG. 5, when a force in the vertical direction is applied to one eccentric side of the ground part 110 rather than the center, the upper electrode part 130a and the second electrode part 130b Each of the parts 132 has a different distance (d _1N , d _2N ) from the flat panel module 112 so that the capacitance values of the first electrode part 130a and the second electrode part 130b are different. do. As described above, the force measuring unit can obtain a vertical force applied to the ground unit 110 by using the change in the capacitance value of the first electrode unit 130a and the second electrode unit 130b together.

In addition, as shown in FIG. 6, when a horizontal force is applied to the ground portion 110 and the ground portion 110 moves horizontally (from left to right in the drawing), the side electrode portion 131 and the insertion module 114 As the distance between them changes, the capacitance value changes. In more detail, the distance d _{1 s} between the side electrode portion 131 of the first electrode portion 130a and the insertion module 114 increases, so that the capacitance value decreases, and the second electrode portion 130b The distance d _2s between the side electrode part 131 and the insertion module 114 becomes close, so that the capacitance value increases. In this way, the force measuring unit may obtain a horizontal force applied to the ground unit 110 by using the value of the capacitance that changes in the first electrode unit 130a and the second electrode unit 130b.

In the force sensor 100 according to the present invention, a cylindrical insertion module 114 having a size slightly smaller than the size of the circular hole 122 formed in the substrate portion 120 is inserted, and the side surface of the hole 122 and the insertion module ( 114) Since a gap is formed between the hole 122 and the insertion module 114, if the center position of the hole 122 and the insertion module 114 are aligned, two electrodes for measuring the force in the horizontal direction can be arranged, so processing is easy, processing error is small, and assembly is easy. There is an advantage to losing.

Furthermore, since the side electrode part 131 formed on the side of the hole 122 and the cylindrical insertion module 114 are spaced apart in the shape of a curved surface, the sensing cross-sectional area is compared with the case where the two electrodes are arranged in the shape of a plane. Since can be increased, the sensitivity of the sensor can be further improved.

Hereinafter, a multiaxial force and torque sensor according to an embodiment of the present invention will be described with reference to FIGS. 7 to 8.

7 is an exploded perspective view of a multiaxial force and torque sensor according to an embodiment of the present invention, and FIG. 8 is a combined perspective view of FIG. 7.

Using the force sensor 100 described above with reference to FIGS. 2 to 6, the force in the vertical direction and the force in the horizontal direction applied to the force sensor 100 may be obtained. In this case, the multiaxial force and torque sensor 200 according to the present invention may be configured by including three or more force sensors 100 and combining each force sensor 100 to have a different azimuth angle. In this case, the plurality of force sensors 100 may be arranged to form various azimuth angles from each other, but the plurality of force sensors 100 may be placed on the same plane but spaced apart from each other at the same distance on the same circumference. By doing so, it is desirable that the force and torque applied from various directions are evenly distributed to each sensor.

In the present embodiment, the multi-axis force and torque means a force (F _x , F _y , F _z ) and torque (T _x , T _y , T _z ) acting in the directions of three orthogonal axes in a Cartesian coordinate system.

The calculation unit (not shown), which is a calculation device, calculates the multi-axis force and the multi-axis torque by using the vertical and horizontal forces measured by the force measuring unit for each force sensor. At this time, the value measured by each force sensor can be calculated according to a mathematical equation to obtain the multi-axial force and the multi-axial torque. Alternatively, since the value of the capacitance formed in each force sensor changes according to the force and torque applied to various sizes and directions, the capacitance values that change according to various sizes and directions are stored in a table in advance and compared. It is also possible to obtain the multiaxial force and torque.

7 and 8 illustrate a multiaxial force and torque sensor 200 using three force sensor structures.

Three circular holes 122 are formed in the substrate portion 120, and the holes 122 are formed on the same circumference at 120 degree intervals at positions corresponding to the vertices of an equilateral triangle. In each of the holes 122, as described above, a side electrode portion 131 and an upper electrode portion 132 are integrally formed at the edge of the hole 122 on the upper surface of the substrate portion 120 of the hole 122, and further The electrode part 130 is formed in a form separated by the first electrode part 130a and the second electrode part 130b in the circumferential direction of the hole 122.

In addition, the ground part 110 is a grounded conductor whose position is changed by an external force, and the flat plate module 112 and the three insertion modules 114 protruding in a cylindrical shape on the lower surface of the flat plate module 112 Is formed, and each insertion module 114 is inserted into the hole 122 formed in the substrate portion 120 at a distance.

As described above, the structure of the force sensor 100 described with reference to FIGS. 2 to 6 may be manufactured in a form in which three structures are formed on a single substrate unit 120.

When an external force is applied to the ground unit 110, the force measurement unit measures the force in the vertical direction and the force in the horizontal direction using the capacitance value for each force sensor structure, and the operation unit measures the vertical force measured by the force measurement unit. The multiaxial force and the multiaxial torque applied to the center of the ground unit 110 may be obtained by using the force in the direction and the force in the horizontal direction.

The scope of the present invention is not limited to the above-described embodiments, but may be implemented in various forms within the scope of the appended claims. Without departing from the gist of the present invention claimed in the claims, any person of ordinary skill in the art to which the present invention belongs is considered to be within the scope of the description of the claims of the present invention to various ranges that can be modified.

100: force sensor
110: ground part
112: flat panel module
114: insert module
120: substrate portion
122: Hall
130: electrode part
130a: first electrode part
130b: second electrode part
131: side electrode part
132: upper electrode portion
140: dielectric
200: multi-axis force and torque sensor

Claims (15)

A grounded conductor whose position is changed by an external force, the ground portion including a flat plate module and an insertion module protruding in a cylindrical shape on a lower surface of the flat plate module;
A plate-shaped substrate, which is formed to be spaced apart from the plate module, and has a circular hole through which the insertion module can be inserted;
An electrode formed on a side surface of the hole and an edge of the hole on an upper surface of the substrate, the electrode portion receiving power and forming a capacitance together with the ground portion; And
A force sensor including a force measuring unit that obtains a force in a vertical direction or a force in a horizontal direction applied to the ground unit using the capacitance value. The method of claim 1,
An electrode formed on the side of the hole and on the edge of the hole on the upper surface of the substrate is integrally formed. The method of claim 1,
The force sensor is formed separately along the circumferential direction of the hole. The method of claim 3,
The force sensor is divided into two or more electrodes along the circumferential direction of the hole. The method of claim 1,
A force sensor in which a dielectric is formed in a space between the flat panel module and the substrate and a space between the hole and the insertion module. The method of claim 5,
The dielectric force sensor is at least one of a polymer, air, and water. Three or more force sensors; And
It includes a calculation unit for obtaining the force and torque of the multi-axis acting on the force sensor,
The force sensor is a force sensor according to any one of claims 1 to 6, wherein the calculation unit uses a vertical force and a horizontal force measured by the three or more force sensors to generate a multiaxial force and Multi-axis force and torque sensor to obtain multi-axis torque. The method of claim 7,
The three or more force sensors are disposed on the same plane, the multiaxial force and torque sensors disposed to be spaced apart from each other at the same distance on the same circumference. A grounded conductor whose position is changed by an external force, the ground portion including a flat plate module and a cylindrical insertion module protruding from a lower surface of the flat module in three or more shapes;
A substrate in the form of a flat plate, which is formed to be spaced apart from the flat module, and has a plurality of circular holes through which three or more insertion modules can be inserted therefrom;
A plurality of electrode portions formed on a side surface of the hole and an edge of a hole on an upper surface of the substrate portion for the plurality of holes, the electrode portions forming a capacitance together with the ground portion by receiving power;
For each of the plurality of electrode units, a force measuring unit for measuring a force in a vertical direction or a force in a horizontal direction applied to the ground unit by using the capacitance value; And
A multi-axial force and torque sensor comprising a calculation unit that calculates a multi-axial force and a multi-axial torque applied to the ground by using the force in the vertical direction and the force in the horizontal direction measured by the force measuring unit. The method of claim 9,
The multiaxial force and torque sensor formed integrally with electrodes formed on the side of the hole and the edge of the hole on the upper surface of the substrate. The method of claim 10,
The electrode unit is a multiaxial force and torque sensor that is separately formed along the circumferential direction of the hole. The method of claim 11,
A multiaxial force and torque sensor that is divided into two or more equal parts along the circumferential direction of the hole. The method of claim 9,
A multiaxial force and torque sensor in which a dielectric is formed in a space between the flat panel module and the substrate and a space between the hole and the insertion module. The method of claim 13,
The dielectric is a multiaxial force and torque sensor of at least one of polymer, air, and water. The method of claim 9,
The insertion module and the hole are multiaxial force and torque sensors disposed to be spaced apart from each other at equal intervals on the same circumference.

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