Inductance measurement-based 6-axis force torque sensing device and 6-axis force torque sensing method

Abstract

The present invention relates to a 6-axis force torque sensing device and a 6-axis force torque sensing method and, more specifically, to an inductance measurement-based 6-axis force torque sensing device and 6-axis force torque sensing method which measure the intensity and direction of an external force by using a change in inductance.

Description

A six-axis force-torque detection device and a six-axis force-torque detection method based on inductance measurement.

[0001] The present invention relates to a 6-axis force torque detection device and a 6-axis force torque detection method, and more particularly, to a 6-axis force torque detection device and a 6-axis force torque detection method based on inductance measurement that measure the intensity and direction of an external force using a change in inductance.

[0002] Force torque measurement technology has been continuously discussed and developed as more sophisticated control is required in the field of robot control.

[0003] Conventional force-torque sensors use 12 or more strain gauges to measure deformation and thereby determine the magnitude and direction of external force. While this method allows for precise force-torque measurements, it is expensive due to the large number of sensors installed, making miniaturization difficult. Furthermore, it has a high failure rate and is vulnerable to shock.

[0004] Additionally, there are capacitance-based force torque sensors that measure the magnitude and direction of external force by measuring the electric capacity between electrode plates. This approach utilizes a single sensor, making it easy to manage, miniaturize, and relatively inexpensive. However, it has the disadvantage of requiring multiple sensing devices in multiple locations to achieve high accuracy. Furthermore, capacitance-based force torque sensors typically utilize integrated circuits (ICs) with 16-bit resolution, requiring higher resolution to achieve higher accuracy.

[0005] Accordingly, research has been conducted in various fields to increase the resolution of integrated circuits (ICs) to improve accuracy, to be shock-resistant, to reduce the time and cost required for manufacturing and management, and to develop miniaturized force / torque measuring devices capable of single-device measurement.

[0006] The present invention relates to a 6-axis force torque detection device and a 6-axis force torque detection method, and more specifically, to provide a 6-axis force torque detection device and a 6-axis force torque detection method based on inductance measurement that measure the intensity and direction of an external force using a change in inductance.

[0007] A six-axis force torque detection device based on inductance measurement according to the present invention comprises: a variable structure that elastically changes by an external force to cause an inductance change in an inductor including a nearby coil; at least six inductance sensors that are arranged at different positions to detect an inductance change of the inductor according to a deformation of the variable structure; and a sensing substrate including the inductance sensors and a support structure that supports the variable structure.

[0008] Additionally, the variable structure may be coupled to the upper side of the sensing substrate at a predetermined interval so as to maintain a non-contact state with the sensing substrate.

[0009] In addition, the inductance sensors may include an LC circuit including a coil and a capacitor acting as the inductor, and an inductance change measuring device that measures a change in inductance of the coil using a change in the resonant frequency of the LC circuit.

[0010] In addition, the 6-axis force torque detection device based on the inductance measurement may further include a data processing unit that calculates the displacement of the variable structure from the inductance change measured through the inductance sensors and calculates the intensity and direction of the external force applied to the variable structure, a communication unit capable of data communication with the outside, and an inertial measurement unit that measures acceleration and angular velocity, including an accelerometer and a gyroscope.

[0011] In addition, the inductance sensors may include a first inductance sensor, a second inductance sensor, a third inductance sensor, a fourth inductance sensor, a fifth inductance sensor, and a sixth inductance sensor. Here, the first coil of the first inductance sensor, the second coil of the second inductance sensor, and the third coil of the third inductance sensor are arranged at 120-degree equal intervals in the center of the sensing substrate, so that the vertical component of the external force applied to the variable structure can be measured using the inductance change detected through the first coil, the second coil, and the third coil. In addition, the fourth coil of the fourth inductance sensor, the fifth coil of the fifth inductance sensor, and the sixth coil of the sixth inductance sensor are arranged at 120-degree intervals at the edge of the sensing substrate, so that the horizontal component of the external force applied to the variable structure can be measured using the inductance change detected through the fourth coil, the fifth coil, and the sixth coil.

[0012] Additionally, the first coil and the fourth coil, the second coil and the fifth coil, and the third coil and the fourth coil may be arranged adjacent to each other as pairs.

[0013] In addition, the variable structure includes a spring member that elastically changes by an external force to cause an inductance change in the inductor, and the spring member includes three beam parts extending radially in a horizontal direction from the center and arranged at 120-degree equal intervals, and the variable structure can be coupled to the support structure so that the beam parts are positioned above the first coil and the fourth coil, the second coil and the fifth coil, and the third coil and the sixth coil, respectively.

[0014] Additionally, a first inductance modulation unit and a second inductance modulation unit can be formed in each of the above beam sections.

[0015] In addition, the first inductance modulation unit is formed in a round shape at the connection portion of the central portion of the beam portion and the variable structure, and is positioned above the first coil, the second coil, and the third coil, so as to change the inductance of the first coil, the second coil, and the third coil, respectively.

[0016] In addition, the second inductance modulation unit is formed in a shape that protrudes sharply in a horizontal direction so as to be adjacent to the outer side of the first inductance modulation unit and is perpendicular to the longitudinal direction of the beam unit along one longitudinal side of the beam unit, and the sharp end of the second inductance modulation unit is positioned above the fourth coil, the fifth coil, and the sixth coil, so that the inductances of the fourth coil, the fifth coil, and the sixth coil can be changed, respectively.

[0017] In addition, the inductance sensors may include a first inductance sensor, a second inductance sensor, a third inductance sensor, a fourth inductance sensor, a fifth inductance sensor, and a sixth inductance sensor. Here, the first horizontal coil of the first inductance sensor, the second horizontal coil of the second inductance sensor, and the third horizontal coil of the third inductance sensor are arranged at equal intervals of 120 degrees with coil surfaces parallel to the sensing substrate, and a vertical component of an external force applied to the variable structure can be measured using an inductance change detected through the first horizontal coil, the second horizontal coil, and the third horizontal coil. In addition, the first vertical coil of the fourth inductance sensor, the second vertical coil of the fifth inductance sensor, and the third vertical coil of the sixth inductance sensor are arranged at 120-degree intervals with coil surfaces perpendicular to the sensing substrate, and the horizontal component of the external force applied to the variable structure can be measured using the inductance change detected through the first vertical coil, the second vertical coil, and the third vertical coil. In addition, the first horizontal coil, the first vertical coil, the second horizontal coil, the second vertical coil, the third horizontal coil, and the third vertical coil can be sequentially arranged at 60-degree intervals.

[0018] Additionally, the variable structure may include a spring member that elastically changes by an external force and a screen member that causes an inductance change in the inductor.

[0019] Here, the screen member may include three wing sections extending radially in a horizontal direction from the center and arranged at 120-degree intervals, and a first inductance modulation section and a second inductance modulation section may be formed on each of the wing sections.

[0020] In addition, the first inductance modulation unit is formed in a cylindrical shape on the lower side of the wing parts and is positioned above the first horizontal coil, the second horizontal coil, and the third horizontal coil, so as to change the inductance of the first horizontal coil, the second horizontal coil, and the third horizontal coil, respectively.

[0021] In addition, the second inductance modulation unit is formed in a plate shape on the lower side of the wing parts and is positioned above the first vertical coil, the second vertical coil, and the third vertical coil, so as to change the inductance of the first vertical coil, the second vertical coil, and the third vertical coil, respectively.

[0022] In addition, the sensing substrate may include a first sensing substrate and a second sensing substrate arranged vertically, the coil may be arranged on the first sensing substrate to detect a change in inductance according to deformation of the variable structure, and a circuit configuration of the sensing substrate including the capacitor and the inductance change measuring device may be arranged on the second sensing substrate.

[0023] A six-axis force torque detection method based on inductance measurement according to the present invention comprises: a step of applying an external force to a variable structure that elastically changes due to an external force and causes an inductance change in an inductor including a surrounding coil, and causing the variable structure to be deformed; a step of detecting, by at least six inductance sensors arranged at different positions, an inductance change of the inductor caused by the deformation of the variable structure; a step of calculating, by a data processing unit, a displacement of the variable structure using the inductance change detected by the inductance sensors; and a step of calculating, by the data processing unit, a magnitude and direction of an external force applied to the variable structure using the displacement of the variable structure.

[0024] In addition, the inductance sensors include an LC circuit including a coil and a capacitor connected to the coil, and an inductance change measuring device connected to the LC circuit and measuring an inductance change of the coil using a change in resonant frequency of the LC circuit, and the step of calculating the magnitude and direction of the external force may be a step of calculating the magnitude and direction of the external force applied to the variable structure by calculating the displacement of the variable structure from the inductance change measured by the inductance change measuring device.

[0025] According to the 6-axis force torque detection device and 6-axis force torque detection method according to the present invention, the intensity and direction of an external force can be measured using a change in inductance.

[0026] Additionally, it is possible to provide higher force torque measurement precision through an inductance change meter that measures inductance change using the resonant frequency change of an LC circuit, which is composed of an integrated circuit (IC) with 24-bit resolution.

[0027] Additionally, since six inductance sensors are arranged on a single substrate, force torque measurement is possible with just one device, which saves time and cost in manufacturing and managing the force torque measurement device and increases space efficiency.

[0028] In addition, a non-contact measurement method is provided in which a predetermined distance is formed between a variable structure that is deformed and changes position by an external force and an inductance sensor, thereby improving the durability and shock resistance of a six-axis force torque device.

[0029] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary knowledge in the technical field to which the present invention belongs (referred to as “one of ordinary skill in the art”) from the description of the claims.

[0030] Embodiments of the present invention will be described below with reference to the accompanying drawings, wherein like reference numerals represent similar elements, but are not limited thereto.

[0031] FIG. 1 is an exploded perspective view of a six-axis force torque sensing device according to a first embodiment of the present invention.

[0032] Figure 2 is a photograph of a completed product in which a six-axis force torque sensing device according to the first embodiment of the present invention is assembled.

[0033] Figure 3 is a block diagram showing a circuit configuration on a sensing substrate according to the first embodiment of the present invention.

[0034] FIG. 4 is a diagram illustrating an embodiment of a circuit diagram for configuring an inductance change measuring device and inductance sensors in a sensing substrate according to a first embodiment of the present invention.

[0035] FIG. 5 (a) is a photograph taken from above of a sensing substrate implemented according to a first embodiment of the present invention. In addition, FIG. 5 (b) is a sensing substrate layout illustrating the arrangement of electronic components and electrical patterns on the sensing substrate according to one embodiment of the present invention.

[0036] FIG. 6 is a photograph taken from above showing a spring member positioned on the upper side of a sensing substrate implemented according to the first embodiment of the present invention.

[0037] FIG. 7 is a time-force graph in the x-axis, y-axis, and z-axis respectively measured by the axial force torque detection device and the MINI-85 sensor according to the first embodiment of the present invention.

[0038] FIG. 8 is a time-moment graph in the x-axis, y-axis, and z-axis measured by the axial force torque detection device and the MINI-85 sensor according to the first embodiment of the present invention, respectively.

[0039] Figure 9 is an exploded perspective view of a six-axis force torque sensing device according to a second embodiment of the present invention.

[0040] Fig. 10 (a) is a schematic diagram of a first sensing substrate according to the second embodiment, and Fig. 10 (b) is a schematic diagram of a vertical coil according to the second embodiment.

[0041] Figure 11 is a flowchart illustrating a six-axis force torque detection method according to the present invention.

[0042] Hereinafter, specific details for implementing the present invention will be described in detail with reference to the attached drawings. However, in the following description, specific descriptions of widely known functions or configurations will be omitted if they may unnecessarily obscure the gist of the present invention.

[0043] In the attached drawings, identical or corresponding components are assigned the same reference numerals. Furthermore, in the description of the embodiments below, duplicate descriptions of identical or corresponding components may be omitted. However, even if a description of a component is omitted, it is not intended that such component is not included in any embodiment.

[0044] The advantages and features of the embodiments disclosed herein, and the methods for achieving them, will become clearer with reference to the embodiments described below, along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to fully inform those skilled in the art of the scope of the invention.

[0045] Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0046] For example, the term "technology" may refer to systems, methods, computer-readable instructions, modules, algorithms, hardware logic, and / or operations as permitted by the context described above and throughout the document.

[0047] The terms used in this specification will be briefly explained, followed by a detailed description of the disclosed embodiments. The terms used in this specification have been selected from widely used, current terms, taking into account the functions of the present invention. However, these terms may vary depending on the intentions of engineers working in the relevant fields, precedents, or the emergence of new technologies. Furthermore, in certain cases, the applicant may arbitrarily select terms, in which case their meanings will be described in detail in the relevant description of the invention. Therefore, the terms used in this specification should not be defined simply based on their names, but rather based on their meanings and the overall content of the present invention.

[0048] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, plural expressions include singular expressions unless the context clearly indicates otherwise. When a part of the specification is said to include a component, this does not exclude other components, but rather implies that other components may be included, unless otherwise specifically stated.

[0049] In the present invention, terms such as “comprise”, “comprising”, etc. may indicate the presence of features, steps, operations, elements, and / or components, but such terms do not exclude the addition of one or more other functions, steps, operations, elements, components, and / or combinations thereof.

[0050] In the present invention, when a specific component is referred to as being "coupled," "combined," "connected," "associated," or "reacting" with any other component, the specific component may be directly coupled, combined, connected, and / or associated with, or reacting with, the other component, but is not limited thereto. For example, one or more intermediate components may exist between the specific component and the other component. Furthermore, in the present invention, "and / or" may include each of one or more listed items or a combination of at least some of one or more items.

[0051] In the present invention, terms such as "first," "second," etc. are used to distinguish specific components from other components, and these terms do not limit the components described above. For example, the term "first" component may be used to refer to an element having the same or similar form as the "second" component.

[0052] In this specification, a 'part' or 'module' includes a unit realized by hardware or software, or a unit realized using both, and one unit may be realized using two or more pieces of hardware, or two or more units may be realized by one piece of hardware.

[0053] In this specification, the vertical direction refers to the z-axis direction on the drawing, and the horizontal direction refers to the x-axis and y-axis directions on the drawing.

[0054] In this specification, screw holes may be replaced with through holes, and through holes may be replaced with screw holes. In this case, when two parts are joined through two through holes, various other joining methods may be used instead of screw joints, including pin joints, tab-slot joints, and mortise-tenon joints.

[0055] The system described below constitutes one embodiment and is not intended to limit the claimed scope to any particular operating environment. It may be used in other environments without departing from the technical spirit and scope of the claimed subject matter.

[0056] Hereinafter, a six-axis force torque detection device (1) according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 6.

[0057] FIG. 1 is an exploded perspective view of a 6-axis force torque detection device (1) according to a first embodiment of the present invention, and FIG. 2 shows a photograph of a completed 6-axis force torque detection device (1) that has been actually implemented and assembled.

[0058] Referring to FIG. 1, a six-axis force torque sensing device (1) according to a first embodiment of the present invention includes a cover structure (100) to which an external force is applied, a variable structure (200) that elastically changes due to the external force to cause an inductance change in a surrounding inductor, an inductance measurement-based sensing substrate (300) that detects a change in the variable structure (200), and a support structure (400) that supports the variable structure (200) and the sensing substrate (300).

[0059] The cover structure (100) may be configured to be coupled to the outside of the spring member (210) of the variable structure (200) so as to transmit an external force to the spring member (210). For example, the cover structure (100) may be coupled to the upper side of the spring member (210) so as to transmit an external force applied from the upper side to the spring member (210). In addition, without being limited thereto, the cover structure (100) may be coupled to various side surfaces of the spring member (210) so as to transmit an external force applied from various directions to the spring member (210).

[0060] The external force applied to the spring member (210) through the cover structure (100) includes various methods and is not limited to a specific method. For example, a predetermined external device (not shown, hereinafter referred to as an external force device) that applies an external force to the cover structure (100) is coupled, and a predetermined external force can be applied to the cover structure (100) from the external force device.

[0061] The cover structure (100) is provided in the shape of a circular plate of uniform thickness, thereby minimizing the occurrence of force transmission variables due to different thicknesses and increasing the accuracy of the strength and direction of the force measured by the sensing substrate (300). In addition, the cover structure (100) is provided with a hard, inelastic metal, thereby absorbing unnecessary external shocks and preventing damage to the spring member (210). The cover structure (100) is not limited thereto and may be formed of various shapes and materials.

[0062] A through hole (H1) for coupling between an external force device and a spring member (210) may be formed in the cover structure (100). An upper protrusion (211) of the spring member (210) may be inserted into the through hole (H1), and an inner surface of the through hole (H1) may be formed in a shape that matches an outer surface of the protrusion (211). In addition, the through hole (H1) may be formed at the center of gravity of the cover structure (100) so that the size and direction of the external force transmitted from the external force device are fully transmitted to the spring member (210), but is not limited thereto and may be formed in various positions.

[0063] Additionally, vertical elastic body-joining screw holes (h1, h2, h3, h4, h5, h6) for screw connection with a spring member (210) may be formed in the central portion (101) of the cover structure (100). Here, the central portion (101) of the cover structure (100) may be an area within a predetermined distance from the center of gravity of the cover structure (100).

[0064] In addition, at least three elastic body-bonding screw holes (h1, h2, h3, h4, h5, h6) may be formed at equal angular intervals centered on the through hole (H1) formed at the center of gravity of the cover structure (100). Accordingly, the size and direction of the external force transmitted from the external force device may be fully transmitted to the spring member (210). Preferably, six elastic body-bonding screw holes (h1, h2, h3, h4, h5, h6) may be formed at 60-degree intervals.

[0065] Additionally, vertical external force device coupling screw holes (h7, h8, h9, h10) for screw coupling with an external force device may be formed at the edge portion (102) of the cover structure (100). Here, the edge portion (102) of the cover structure (100) may be an area between the center portion (101) and the edge of the cover structure (100).

[0066] In addition, the external force device coupling screw holes (h7, h8, h9, h10) may be formed at equiangular intervals on the outside of the elastic body coupling screw holes (h1, h2, h3, h4, h5, h6) centered on the through hole (H1) formed at the center of gravity of the cover structure (100). Accordingly, the size and direction of the external force transmitted from the external force device may be fully transmitted to the spring member (210). Preferably, four external force device coupling screw holes (h7, h8, h9, h10) may be formed at 90-degree intervals.

[0067] The variable structure (200) may be an elastic body that can be elastically deformed by an external force, and at the same time, an inductance modulator that causes an inductance change in a surrounding inductor.

[0068] In addition, the variable structure (200) may include a spring member (210) that is elastically deformed by an external force, and a variable structure frame (220) that supports the spring member (210) and fixes the variable area.

[0069] The variable structure frame (220) may be a cylindrical structure with the top and bottom open, and may be configured in such a way that a spring member (210) is coupled to the inside and a support structure (400) is coupled to the bottom. Here, the variable structure frame (220) may have vertical support structure coupling screw holes (h17, h18, h19, h20, h21, h22) formed at regular intervals for screw coupling with the support structure (400).

[0070] In addition, a cover structure (100) in the shape of a circular plate is coupled to the upper side of the spring member (210), and the inner diameter of the upper end of the variable structure frame (220) is formed to be larger than the diameter of the cover structure (100), so that the cover structure (100) can be configured to be introduced into the inner side of the variable structure frame (220). In this case, a predetermined distance may be formed between the cover structure (100) and the variable structure frame (220), so that the cover structure (100) can be easily moved in the vertical direction and tilted by an external force.

[0071] In addition, although not shown in the drawing, the inner diameter of the upper end of the variable structure frame (220) may be formed smaller than the diameter of the cover structure (100), so that the cover structure (100) may be configured to be positioned on the upper side of the variable structure frame (220). In this case, a predetermined distance may be formed between the lower end of the cover structure (100) and the upper end of the variable structure frame (220), so that the cover structure (100) may be configured to easily move vertically and tilt due to an external force.

[0072] The spring member (210) may be formed of a material that can be elastically deformed by an external force, such as an elastic metal, rubber, silicone, or polyurethane. In addition, the spring member (210) may be formed of a material that changes the inductance of the coil (321, 331, 341, 351, 361, 371), which is an inductor included in the sensing substrate (300), according to a change in position. The material that changes the inductance may be a non-magnetic material as well as a paramagnetic material and a diamagnetic material. For example, the spring member (210) may be a material containing iron or nickel, and may be formed of an AL7075-T6 material, but is not limited thereto and may be formed of various types of materials.

[0073] Depending on the size and direction of the external force acting on the spring member (210), the spring member (210) is deformed and its position can move up and down, and the inclination changes so that the displacement of the spring member (210) with different values ​​can be measured from the inductance sensors (320, 330, 340, 350, 360, 370).

[0074] The spring member (210) is formed to have a uniform thickness in the vertical direction, thereby minimizing the occurrence of force transmission variables due to different thicknesses and increasing the accuracy of the strength and direction of the force measured by the sensing substrate (300).

[0075] The spring member (210) may be provided with a cross elastic beam structure. Specifically, it may be composed of a central portion (212) which is an area within a predetermined distance from the center of gravity, and at least three beam portions (213, 214, 215) which extend radially in a horizontal direction from the central portion (212) and have their ends each fixed to a variable structure frame (220).

[0076] A protrusion (211) having a vertical screw hole (h211) may be formed at the upper end of the central portion (212) of the spring member (210). The protrusion (211) may be inserted from below into the through hole (H1) of the cover structure (100), may be formed in a shape that conforms to the inner surface of the through hole (H1), and may be screw-coupled to an external device through the screw hole (h211). Here, the screw hole (h211) of the protrusion (211) may be formed in a shape in which the upper end is open and the lower end is closed. In addition, the screw hole (h211) of the protrusion (211) may be formed at the upper center of gravity of the spring member (210). In addition, the present invention is not limited thereto, and the protrusion (211) and the screw hole (h211) may be formed in various ways.

[0077] In addition, vertical cover coupling screw holes (h11, h12, h13, h14, h15, h16) for screw coupling with the cover structure (100) may be formed in the central portion (212) of the spring member (210). In addition, the cover coupling screw holes (h11, h12, h13, h14, h15, h16) may be formed in the same number and at corresponding positions as the elastic body coupling screw holes (h1, h2, h3, h4, h5, h6) of the cover structure (100), and the cover structure (100) and the spring member (210) may be coupled by coupling screws to the corresponding screw holes of each pair. For example, six elastic body-joining screw holes (h1, h2, h3, h4, h5, h6) and six cover-joining screw holes (h11, h12, h13, h14, h15, h16) can be formed at 60-degree intervals with the same spacing distance centered on the through hole (H1) and the protrusion (211).

[0078] The beam sections (213, 214, 215) of the spring member (210) may be formed at equal angular intervals centered on the central section (212) of the spring member (210). Preferably, three beam sections (213, 214, 215) may be formed at 120-degree intervals. Accordingly, the spring member (210) may be stably fixed to the variable structure frame (220) and may be deformed to reflect the direction of an external force.

[0079] In addition, the spring member (210) may be formed as a single configuration including a central portion (212) and beam portions (213, 214, 215), or may be formed by combining the central portion (212) and beam portions (213, 214, 215), each of which is formed as a separate configuration. When the spring member (210) is a single configuration, the spring member (210) may be formed of a single material that is elastically deformable by an external force. In addition, when the central portion (212) and beam portions (213, 214, 215) of the spring member (210) are separate configurations, the central portion (212) and beam portions (213, 214, 215) may be formed of different materials. For example, the central portion (212) may be a circular plate made of an inelastic material, and the beam portions (213, 214, 215) may be formed of separate elastic materials. In addition, the central portion (212) and the beam portions (213, 214, 215) may be formed of elastic materials of different materials.

[0080] The beam portions (213, 214, 215) of the spring member (210) can be configured to include a first inductance modulation portion (213-1, 214-1, 215-1) and a second inductance modulation portion (213-2, 214-2, 215-2).

[0081] The first inductance modulation unit (213-1, 214-1, 215-1) may be positioned vertically above the coils (321, 331, 341) arranged in the central portion (311) of the substrate (310) on the sensing substrate (300), and may be formed in a round shape at the connection portion with the central portion (212). According to this configuration, deformation and positional movement of the first inductance modulation unit (213-1, 214-1, 215-1) due to an external force may cause changes in the inductance of the coils (321, 331, 341) arranged in the central portion (311) of the substrate (310), respectively. In addition, by using the measured inductance change, the vertical displacement of the first inductance modulation unit (213-1, 214-1, 215-1) is calculated in the data processing unit (393), and through this, the vertical magnitude of the external force applied to the six-axis force torque device (1) can be calculated.

[0082] In addition, the second inductance modulation units (213-2, 214-2, 215-2) may be positioned vertically above the coils (351, 361, 371) arranged on the edge portion (312) of the substrate (310) on the sensing substrate (300). To this end, the second inductance modulation units (213-2, 214-2, 215-2) may be formed at a position adjacent to the outside of the first inductance modulation units (213-1, 214-1, 215-1), and may be provided in a shape that protrudes sharply in the horizontal direction so as to be perpendicular to the longitudinal direction of the beam units (213, 214, 215) on one longitudinal side of the beam units (213, 214, 215). Here, the pointed ends of the second inductance modulation units (213-2, 214-2, 215-2) may be arranged to be vertically upward from the center of the coils (351, 361, 371) arranged at the edge portion (312) of the substrate (310). According to this configuration, the positional movement of the second inductance modulation units (213-2, 214-2, 215-2) may cause changes in the inductance of the coils (351, 361, 371) arranged at the edge portion (312) of the substrate (310), respectively. In addition, by using the measured inductance change, the horizontal displacement of the second inductance modulation unit (213-2, 214-2, 215-2) is calculated in the data processing unit (393), and through this, the horizontal magnitude of the external force applied to the six-axis force torque device (1) can be calculated.

[0083] As described above, according to the configuration in which the spring member (210) serves both as an elastic body and an inductance modulator, manufacturing and management are easier than in the case in which the elastic body function and the inductance modulator function are provided separately, and the time and cost required for manufacturing and management can be further reduced. In addition, the 6-axis force torque detection device can be made more compact, thereby saving installation space.

[0084] In addition, the variable structure frame (220) may be configured to share the role of the spring member (210) by being made of a material that can be elastically deformed by an external force. Here, the variable structure frame (220) may be configured of the same material as the spring member (210). In this case, the variable structure frame (220) and the spring member (210) may be manufactured as separate parts and then combined, or may be manufactured as one integral part. If the variable structure frame (220) and the spring member (210) are manufactured of the same material, the time and cost required for manufacturing and management can be reduced. In addition, the variable structure frame (220) and the spring member (210) may be manufactured of different materials. As described above, if the variable structure frame (220) is elastically deformable, external forces applied from a wider range of directions can be measured, thereby improving the force torque measurement range of the sensing substrate (300) and increasing usability.

[0085] Additionally, the variable structure frame (220) may be composed of a rigid, inelastic metal material of uniform thickness. In this case, the variable structure frame (220) is manufactured as a separate part from the spring member (210) and is combined therewith, and can maintain a consistently fixed frame without being deformed by external force, thereby minimizing force torque measurement variables of the sensing substrate (300) and increasing accuracy.

[0086] A variable structure (200) and a sensing substrate (300) may be coupled to a support structure (400). Specifically, the variable structure (200) may be coupled to the upper side of the sensing substrate (300) at a predetermined interval.

[0087] For example, the support structure (400) may be a cylindrical structure having an accommodation space (s) formed on the inside and an open top, and a sensing substrate (300) may be coupled to the accommodation space (s) of the support structure (400), and a variable structure (200) may be coupled to the open top of the support structure (400). Here, the gap between the variable structure (200) and the sensing substrate (300) may be set differently depending on the deformation range of the variable structure (200), and may be set so as to maintain a non-contact state with the sensing substrate (300) even when the variable structure (200) is deformed to the maximum.

[0088] In addition, vertical variable structure coupling through holes (H5, H6, H7, H8, H9, H10) having steps formed so that the upper part becomes narrower than the lower part for coupling with the variable structure (200) at the edge of the support structure (400) may be formed at regular intervals. The variable structure coupling through holes (H5, H6, H7, H8, H9, H10) may be provided in a number and shape corresponding to the support structure coupling screw holes (h17, h18, h19, h20, h21, h22) of the variable structure frame (220). Here, screws (not shown) can be fastened to the support structure coupling screw holes (h17, h18, h19, h20, h21, h22) through the variable structure coupling through holes (H5, H6, H7, H8, H9, H10) from the lower side of the support structure (400), and the screw heads can be fixed by being caught on the step portions of the variable structure coupling through holes (H5, H6, H7, H8, H9, H10).

[0089] In addition, substrate coupling screw holes (h23, h24, h25) for coupling with the sensing substrate (300) may be formed at regular intervals on the inside of the support structure (400). The substrate coupling screw holes (h23, h24, h25) may be provided in a number and shape corresponding to the support structure coupling through holes (H2, H3, H4) of the sensing substrate (300). Here, screws (not shown) may be fastened to the substrate coupling screw holes (h23, h24, h25) through the support structure coupling through holes (H2, H3, H4) from the upper side of the sensing substrate (300), respectively.

[0090] Additionally, the support structure (400) may further be provided with an external connection portion (401) through which a wire connected to the sensing substrate (300) can be connected to an external device.

[0091] FIGS. 3 to 6 illustrate drawings for explaining the configuration of a sensing substrate (300) according to a first embodiment of the present invention. FIG. 3 is a block diagram schematically illustrating a circuit arrangement on a sensing substrate (300), and FIG. 4 illustrates an exemplary circuit diagram for configuring an inductance change measuring device (381, 382) and inductance sensors (330, 340, 350, 360, 370) among the circuit configurations of the sensing substrate (300). In addition, FIG. 5 (a) illustrates a top view photograph of a sensing substrate (300) implemented according to the first embodiment of the present invention, and FIG. 5 (b) illustrates a sensing substrate layout illustrating the arrangement of electronic components and an electrical pattern on the sensing substrate (300). In addition, FIG. 6 shows a photograph taken from the upper side showing a spring member (210) positioned on the upper side of a sensing substrate (300) implemented according to the first embodiment of the present invention.

[0092] The sensing substrate (300) may be configured with at least six inductance sensors (320, 330, 340, 350, 360, 370) including an LC circuit and an inductance change measuring device (381, 382) that measures the inductance change of a coil by using the change in the resonant frequency of the LC circuit on a substrate (310) on which a conductive pattern is formed.

[0093] The substrate (310) is used to physically fix electronic components and provide electrical connections to form an electronic circuit, and may be a PCB (Printed Circuit Board), and may be provided as any one of an FPCB (Flexible Printed Circuit Board), a Ceramic Substrate, an LTCC (Low Temperature Co-fired Ceramic), an MCPCB (Metal Core PCB), and a Glass Fiber Substrate. In addition, it may be a hybrid substrate formed by mixing various substrate materials, or may be formed as a multilayer substrate. In addition, the substrate (310) may be provided in a circular plate shape. In addition, the present invention is not limited thereto, and various types of substrates may be provided in various shapes.

[0094] The LC circuit of each inductance sensor (320, 330, 340, 350, 360, 370) includes a coil (321, 331, 341, 351, 361, 371) and a capacitor (322, 332, 342, 352, 362, 372). When the spring member (210) is deformed by an external force, the inductance of the coil (321, 331, 341, 351, 361, 371) changes, and accordingly, the resonant frequency of the LC circuit changes. Here, the inductance change measuring device (381, 382) can measure the inductance change according to the change in the resonant frequency of the LC circuit, thereby calculating the external force.

[0095] For example, the inductance change measuring device (381, 382) may be a device that calculates inductance change by measuring impedance change according to change in resonant frequency of an LC circuit. In addition, without being limited thereto, a device that measures inductance change in various ways may be provided.

[0096] In addition, the inductance sensors (320, 330, 340, 350, 360, 370) include a first inductance sensor (320) including a first coil (321) and a first capacitor (322), a second inductance sensor (330) including a second coil (331) and a second capacitor (332), a third inductance sensor (340) including a third coil (341) and a third capacitor (342), a fourth inductance sensor (350) including a fourth coil (351) and a fourth capacitor (352), a fifth inductance sensor (360) including a fifth coil (361) and a fifth capacitor (362), and a sixth inductance sensor (371) including a sixth capacitor (372). It may include a sensor (370).

[0097] The inductance sensors (320, 330, 340, 350, 360, 370) may be arranged at different locations on the substrate (310) and configured to detect a change in the position of the spring member (210) at each location. For example, as shown in FIGS. 5 (a) and 5 (b), some may be arranged at equal angular intervals at the center of the substrate (310) to measure the vertical component of the external force, and the remaining some may be arranged at equal angular intervals at the edge of the substrate (310) to measure the horizontal component of the external force. Here, by measuring the displacement of the spring member (210) through the inductance sensors arranged at the edge of the substrate (310), a change in inclination can be measured, and thus the direction of the external force can be calculated.

[0098] Preferably, the first coil (321) of the first inductance sensor (320), the second coil (331) of the second inductance sensor (330), and the third coil (341) of the third inductance sensor (340) may be arranged at 120-degree equal intervals at the center of the substrate (310) to measure the vertical component of the external force. In addition, the fourth coil (351) of the fourth inductance sensor (350), the fifth coil (461) of the fifth inductance sensor (460), and the sixth coil (471) of the sixth inductance sensor (470) may be arranged at 120-degree equal intervals at the edge of the substrate (310) to measure the horizontal component of the external force.

[0099] That is, coils arranged at 120-degree intervals measure the displacement of the spring member (210) at each location, and by comparing the measured displacements to calculate the change in inclination of the spring member (210), the intensity and direction of the external force can be measured with high accuracy. In addition, the present invention is not limited thereto, and inductance sensors (320, 330, 340, 350, 360, 370) can be provided at various locations.

[0100] In addition, the first coil (321) of the first inductance sensor (320) and the fourth coil (351) of the fourth inductance sensor (350), the second coil (331) of the second inductance sensor (330) and the fifth coil (361) of the fifth inductance sensor (360), the third coil (341) of the third inductance sensor (340) and the sixth coil (371) of the sixth inductance sensor (370), which are respectively arranged in the center and the edge of the substrate (310), may be arranged in pairs adjacent to each other.

[0101] In addition, as shown in Fig. 6, each pair of coils (321; 351, 331; 361, 341; 371) may be positioned at a predetermined interval on the lower side of the three beam portions (213, 214, 215) of the spring member (210). At this time, the coils (321, 331, 341) positioned at the center of the substrate (310) may be positioned so as to be positioned on the vertical lower side of the first inductance modulation portions (213-1, 214-1, 215-1) of the beam portions (213, 214, 215) of the spring member (210). In addition, the coils (351, 361, 371) arranged at the edge portion may be arranged to be positioned vertically below the end portion of the second inductance modulation portion (213-2, 214-2, 215-2) of the beam portion (213, 214, 215). Referring to FIG. 5, it can be confirmed that the coils (351, 361, 371) arranged at the edge portion of the substrate (310) are arranged diagonally outwardly adjacent to the coils (321, 331, 341) arranged at the center portion. As described above, by matching the positions of each pair of coils (321; 351, 331; 361, 341; 371) with the positions of the first inductance modulation unit (213-1, 214-1, 215-1) and the second inductance modulation unit (213-2, 214-2, 215-2), the inductance sensors (320, 330, 340, 350, 360, 370) can more accurately detect the change in position of the spring member (210).

[0102] In addition, the inductance change measuring device (381, 382) may be connected to one LC circuit to measure the inductance change of the connected LC circuit, or may be connected to a plurality of LC circuits to measure the inductance change of each of the connected LC circuits.

[0103] For example, two LC circuits may be connected to one inductance change measuring device (381, 382) to measure the inductance changes of the connected LC circuits, respectively. In this case, six inductance sensors (320, 330, 340, 350, 360, 370) may be configured using the two inductance change measuring devices (381, 382).

[0104] Referring to Fig. 4, two LDC1614 units (IC1, IC2) acting as inductance change measuring devices (381, 382) may be provided. In addition, it can be confirmed that coils (L1, L2, L3) and capacitors (C9, C10, C11) are connected in parallel to the first input pair (IN0A, IN0B), the second input pair (IN1A, IN1B) and the third input pair (IN2A, IN2B) of the first LDC1614 unit (IC1), and coils (L4, L5, L6) and capacitors (C12, C13, C14) are connected in parallel to the first input pair (IN0A, IN0B), the second input pair (IN1A, IN1B) and the third input pair (IN2A, IN2B) of the second LDC1614 unit (IC2). Here, the drawing shows the positive terminals (L1A, L1B, L2A, L2B, L3A, L3B, L4A, L4B, L5A, L5B, L6A, L6B) of each coil (L1, L2, L3, L4, L5, L6). The LDC1614 unit (IC1, IC2) acts as an inductance change measuring device (381) that measures the inductance change of each coil by using the change in resonant frequency of each of the three connected LC circuits, and can convert the measured inductance change into a digital signal and transmit it to the data processing unit (393).

[0105] Additionally, although not shown in the drawing, three LDC1612 units can be used as inductance change sensors. In this case, six inductance sensors can be configured by connecting an LC circuit containing two coils and a capacitor to each of the three LDC1612 units. Furthermore, various configurations are possible in which one or more LC circuits are connected to a single inductance change sensor.

[0106] Here, the LDC1614 unit and the LDC1612 unit are configured as integrated circuits (ICs) with 24-bit resolution, which can provide high-accuracy force torque measurements.

[0107] Additionally, a communication unit (391), an inertial measurement unit (392), and a data processing unit (393) may be further configured on the substrate (310) of the sensing substrate (300).

[0108] The communication unit (391) is a communication module configured to be capable of communicating with other devices and can transmit data measured by the inductance sensors (320, 330, 340, 350, 360, 370) to other external system components. An example of the communication unit (391) is a CAN transceiver (391), but is not limited thereto and various types of data processing units may be used.

[0109] The inertial measurement unit (392) can measure 3-axis acceleration and angular velocity to provide current position and movement data, thereby improving the accuracy of measuring the magnitude and direction of external force, especially in a dynamic environment. The measurement data of the inertial measurement unit (392) can be transmitted to the data processing unit (393) and reflected in the calculation of the 6-axis force torque measurement accuracy. In addition, the temperature compensation function of the inertial measurement unit (392) can be reflected in the 3-axis acceleration and angular velocity measurements, thereby reducing measurement errors due to temperature changes. Here, the 6-axis force torque detection device (1) may further be equipped with a temperature sensor (not shown) for measuring temperature, and the temperature value measured by the temperature sensor may be set to be transmitted to the inertial measurement unit (392).

[0110] An example of an inertial measurement unit (392) is an IMU (Inertial Measurement Unit) including an accelerometer (not shown) and a gyroscope (not shown), but is not limited thereto and various types of inertial measurement units may be used.

[0111] The data processing unit (393) can receive the inductance change measured by the inductance sensors (320, 330, 340, 350, 360, 370) to calculate the displacement of the spring member (210), and can use this to calculate the intensity and direction of the external force. In addition, the measurement data of the inertial measurement unit (392) can be received and reflected in the calculation of the intensity and direction of the external force. In addition, the temperature compensation function of the data processing unit (393) can be reflected in the calculation of the intensity and direction of the external force, thereby reducing the measurement error due to temperature change. Here, the temperature value of the 6-axis force torque detection device (1) measured by the temperature sensor can be transmitted to the data processing unit (393). In addition, the operation of the entire sensing system configured on the sensing substrate (300) can be controlled. An example of the data processing unit (392) is an MCU (Microcontroller Unit), but is not limited thereto, and various types of data processing units can be used.

[0112] The sensing substrate (300) can be connected to an external device such as a power supply, a display device, or a computing device through an external connection portion (401) of the support structure (400). In addition, although not shown in the drawing, a power supply can be further accommodated in the accommodation space (s) of the support structure (400), and the sensing substrate (300) can be connected to the power supply so that it can be operated without external power.

[0113] Figures 7 and 8 illustrate experimental examples comparing the performance of a 6-axis force torque detection device (Proposed sensor) according to the present invention and a high-precision force torque sensor, the MINI-85 sensor (Reference sensor).

[0114] The proposed sensor (6-axis force torque sensing device) used in this experimental example follows the description of Figs. 1 to 7. In addition, on the sensing substrate, one of the central coils was positioned 13 mm away from the center in the x-direction, and one of the edge coils was positioned 18.5 mm away from the center in the x-direction and 5 mm away from the center in the y-direction, forming a pair, and three pairs of coils were arranged at 120-degree intervals. In addition, the spring member was made of AL7075-T6, had a height of 7 mm, and a radius of 32.5 mm. In addition, the spring member was coupled to be positioned 1 mm to 0.5 mm vertically upward of the substrate.

[0115] FIG. 7 illustrates time-force graphs in the x-axis, y-axis, and z-axis measured by the 6-axis force torque detection device (Proposed sensor) and the MINI-85 sensor (Reference sensor) according to the present invention, respectively. In addition, FIG. 8 illustrates time-moment graphs in the x-axis, y-axis, and z-axis measured by the 6-axis force torque detection device (Proposed sensor) and the MINI-85 sensor (Reference sensor) according to the present invention, respectively.

[0116] Referring to FIGS. 7 and 8, it can be confirmed that the measurement values ​​of the 6-axis force torque detection device (1) according to the present invention are almost identical to the measurement values ​​of the MINI-85 sensor. Accordingly, it can be confirmed that the measurement accuracy of the 6-axis force torque detection device (1) according to the present invention is very high.

[0117] Hereinafter, a 6-axis force torque detection device (1000) according to a second embodiment of the present invention will be described with reference to FIGS. 9 and 10.

[0118] Fig. 9 is an exploded perspective view of a six-axis force torque sensing device (1000) according to a second embodiment of the present invention. In addition, Fig. 10 (a) illustrates a configuration diagram of a first sensing substrate (1300A) according to the second embodiment, and Fig. 10 (b) schematically illustrates vertical coils (1324, 1325, 1326).

[0119] Referring to FIG. 9, a six-axis force torque sensing device (1000) according to a second embodiment of the present invention follows the first embodiment, but differs from the first embodiment in that a spring member (1210) included in a variable structure (200) is made of a material that can be elastically deformed by an external force, a screen member (1220) that causes an inductance change in a surrounding inductor is provided in a separate configuration from the spring member (1210), and horizontal coils (1321, 1322, 1323) and vertical coils (1324, 1325, 1326) are configured on a first sensing substrate (1300).

[0120] According to the second embodiment, the spring member (1210) can only function as an elastic body without acting as an inductance modulator. Accordingly, the beam portions (1212, 1213, 1214) of the spring member (1210) can be provided in a shape that extends horizontally radially from the central portion (1211) and has its ends fixed to the variable structure frame (1230).

[0121] Screen-joining through holes (H104, H105, H106) for screw connection with the screen member (1220) may be formed in the central portion (1211) of the spring member (1210). For example, three screen-joining through holes (H104, H105, H106) may be formed at 120-degree intervals with the same spacing distance at positions corresponding to the three spring-joining screw holes (h117, h118, h119) of the screen member (1220). Here, the through holes (H104, H105, H106) may be formed with a step so that the bottom is narrower than the top. Accordingly, the spring member (1210) and the screen member (1220) can be joined by screws being joined to the spring-joint screw holes (h117, h118, h119) through each pair of screen-joint through-holes (H104, H105, H106).

[0122] In addition, cover coupling screw holes (h114, h115, h116) for screw coupling with the cover structure (1100) may be formed in the central portion (1211) of the spring member (1210). For example, three cover coupling screw holes (h114, h115, h116) may be formed at 120-degree intervals with the same spacing distance at positions corresponding to the three elastic body coupling through holes (H101, H102, H103) of the cover structure (1100). Here, the elastic body coupling through holes (H101, H102, H103) may be formed with a step so that the bottom is narrower than the top. Accordingly, the cover structure (1100) and the spring member (1210) can be coupled by screws being coupled to the cover coupling screw holes (h104, h105, h106) through each pair of elastic body coupling through-holes (H101, H102, H103). In addition, the cover coupling screw holes (h114, h115, h116) can be formed on the outside of the screen coupling through-holes (H104, H105, H106).

[0123] Additionally, the variable structure (1200) may further include a support member (1240) that supports the lower end of the spring member (1210) and is coupled to the support structure (1400). In this case, the spring member (1210) may be fixed to the upper end of the support member (1240). The support member (1240) may be formed in a ring shape, but is not limited thereto and may be formed in various shapes.

[0124] In addition, the support member (1240) may have protrusions (1241, 1242, 1243) formed downward, and support structure-joining screw holes (h129, h130, h131) may be formed on the inner side of the protrusions (1241, 1242, 1243). For example, three protrusions (1241, 1242, 1243) may be formed at 120-degree intervals with the same spacing distance at positions corresponding to the three variable structure-joining through-holes (H113, H114, H115) of the first support structure (1400A), and the outer surfaces of the protrusions (1241, 1242, 1243) may be formed to be aligned with the inner surfaces of the variable structure-joining through-holes (H113, H114, H115). In addition, three support structure coupling screw holes (h129, h130, h131) can be formed at 120-degree intervals with the same spacing distance at positions corresponding to the three variable structure coupling screw holes (h126, h127, h128) of the second support structure (1400B). Accordingly, the protrusions (1241, 1242, 1243) of the support member (1240) can be fitted into the variable structure coupling through holes (H113, H114, H115), and the support member (1240) and the support structure (1400) can be screw-coupled through the support structure coupling screw holes (h129, h130, h131) and the variable structure coupling screw holes (h126, h127, h128).

[0125] In addition, a cover structure (1100) may be placed on the upper side and the outer side in the circumferential direction of the variable structure frame (1230) of the variable structure (1200). In this case, a predetermined distance may be formed between the upper side of the variable structure frame (1230) and the lower side of the cover structure (1100), and between the outer side of the variable structure frame (1230) and the inner side of the cover structure (1100), so that the cover structure (100) can be easily moved in the vertical direction and tilted by an external force.

[0126] The cover structure (1100) may have elastic body-bonding through holes (H101, H102, H103) formed in the central portion (1101) for screw connection with a spring member (1210), and external force device-bonding screw holes (h111, h112, h113) formed in the edge portion (102) for screw connection with an external force device. Here, the elastic body-bonding through holes (H101, H102, H103) and the external force device-bonding screw holes (h111, h112, h113) may be formed at 120-degree intervals with a constant distance between them.

[0127] In addition, according to the second embodiment, the screen member (1220) may be an inductance modulator made of a material that changes the inductance of the coils (1321, 1322, 1323, 1324, 1325, 1326) included in the sensing substrate (1300) according to a change in position. The screen member (1220) may be a non-magnetic material as well as a paramagnetic material and a diamagnetic material, and may be a material containing iron or nickel, but is not limited thereto and may be made of various types of materials.

[0128] The screen member (1220) may be configured to be coupled to the lower end of the spring member (1210) and to change position according to deformation of the spring member (1210). For example, the inclination and vertical position of the screen member (1220) may change according to deformation of the spring member (1210), and the change in the inclination and vertical position of the screen member (1220) may reflect the direction and intensity of an external force.

[0129] The screen member (1220) may include a central portion (1221) in the shape of a plate located at the center, and at least three wing portions (1222, 1223, 1224) extending horizontally radially from the central portion (1221).

[0130] Spring-coupled screw holes (h117, h118, h119) for coupling with the spring member (1210) may be formed in the central portion (1221) of the screen member (1220). For example, three spring-coupled screw holes (h117, h118, h119) may be formed at 120-degree intervals and may be formed at positions corresponding to the three screen-coupled through holes (H104, H105, H106) of the spring member (1210).

[0131] Additionally, vertical spring-cover coupling through holes (H107, H108, H109) for coupling with the spring member (1210) and the cover structure (1100) may be further formed in the central portion (1221) of the screen member (1220). The spring-cover coupling through holes (H107, H108, H109) may be formed at positions corresponding to the cover coupling screw holes (h114, h115, h116) of the spring member (1210) and the elastic coupling through holes (H101, H102, H103) of the cover structure (1100).

[0132] The wing parts (1222, 1223, 1224) of the screen member (1220) may be provided in a fan-shaped plate shape that is arranged radially at equal angular intervals with the center part (1221) as the center, and has a constant central angle, and may be configured to include a first inductance modulation part (1222a, 1223a, 1224a) and a second inductance modulation part (1222b, 1223b, 1224b). For example, three wing parts (1222, 1223, 1224) having a central angle of 120 degrees may be provided at 120 degree intervals, and a constant, predetermined distance may be formed between each of the wing parts (1222, 1223, 1224).

[0133] The first inductance modulation units (1222a, 1223a, 1224a) may be configured to protrude downward from the fan-shaped wing portions (1222, 1223, 1224), and preferably, may be provided in a cylindrical shape with a closed bottom. Here, the first inductance modulation units (1222a, 1223a, 1224a) may be configured to have a filled interior or an empty interior. In addition, the first inductance modulation units (1222a, 1223a, 1224a) may be provided at a fixed position downward from the wing portions (1222, 1223, 1224), and may be arranged at equal angular intervals with respect to the central portion (1221) of the screen member (1220). For example, when three wing parts (1222, 1223, 1224) having a central angle of 120 degrees are arranged at 120-degree intervals, the first inductance modulation parts (1222a, 1223a, 1224a) configured in each wing part (1222, 1223, 1224) may be arranged at 120-degree intervals. In addition, the first inductance modulation parts (1222a, 1223a, 1224a) are not limited thereto and may be provided in various forms.

[0134] The second inductance modulation units (1222b, 1223b, 1224b) may be configured to extend vertically downwards by a constant width and height from one end of the fan-shaped wing units (1222, 1223, 1224). Accordingly, they may be arranged at equal angular intervals with the center portion (1221) of the screen member (1220) as the center, and may be formed in the radial direction of the screen member (1220). For example, when three wing units (1222, 1223, 1224) having a central angle of 120 degrees are arranged at 120-degree intervals, the second inductance modulation units (1222b, 1223b, 1224b) configured in each of the wing units (1222, 1223, 1224) may be arranged at 120-degree intervals. In addition, the second inductance modulation unit (1222b, 1223b, 1224b) may be provided in the shape of a vertical plate protruding from the bottom of the fan-shaped wing unit (1222, 1223, 1224), but is not limited thereto and may be provided in various shapes.

[0135] In addition, when three wing parts (1222, 1223, 1224) having a central angle of 120 degrees are arranged at 120-degree intervals, the first inductance modulation parts (1222a, 1223a, 1224a) and the second inductance modulation parts (1222b, 1223b, 1224b) can be arranged alternately at 60-degree intervals.

[0136] As described above, the spring member (1210) and the screen member (1220) are configured separately, and the first inductance modulation unit (1222a, 1223a, 1224a) and the second inductance modulation unit (1222b, 1223b, 1224b) for measuring the vertical force of the external force are configured separately, thereby minimizing crosstalk and increasing the accuracy of the force torque sensor.

[0137] Additionally, according to the second embodiment, the sensing substrate may include a first sensing substrate (1300A) and a second sensing substrate (1300B).

[0138] Referring to FIG. 10, the first sensing substrate (1300A) may have at least three horizontal coils (1321, 1322, 1323) and at least three vertical coils (1324, 1325, 1326) arranged on the first substrate (1310). The first substrate (1310) may be provided in a circular plate shape, and may have slits (1311, 1312, 1313) formed therein, in which the vertical coils (1324, 1325, 1326) are arranged. Here, the slits (1311, 1312, 1313) may be formed in the radial direction of the circular plate, may be formed at a predetermined interval, and may be formed in various shapes without being limited thereto.

[0139] The horizontal coils (1321, 1322, 1323) may be circular flat coils having a coil surface parallel to the first substrate (1310), and may be arranged on the first substrate (1310) so as to be positioned below the first inductance modulation units (1222a, 1223a, 1224a), respectively. The horizontal coils (1321, 1322, 1323) may be used to detect a change in the position of the first inductance modulation units (1222a, 1223a, 1224a) located above them, and measure the vertical intensity of an external force applied to the spring member (1210).

[0140] The vertical coils (1324, 1325, 1326) may be rectangular planar coils having a coil surface perpendicular to the first substrate (1310), and may be arranged on the first substrate (1310) so as to be positioned below the second inductance modulation units (1222b, 1223b, 1224b), respectively. The vertical coils (1324, 1325, 1326) may be used to detect a change in the position of the second inductance modulation units (1222b, 1223b, 1224b) located above them, and measure the horizontal intensity of an external force applied to the spring member (1210). Here, the arrangement directions of the vertical coils (1324, 1325, 1326) and the second inductance modulation units (1222b, 1223b, 1224b) can be aligned so that the vertical coils (1324, 1325, 1326) can more accurately detect the positional changes of the second inductance modulation units (1222b, 1223b, 1224b). For example, when the second inductance modulation units (1222b, 1223b, 1224b) are formed in the radial direction of the screen member (1220), the vertical coils (1324, 1325, 1326) can be arranged in the radial direction of the first substrate (1310).

[0141] As described above, horizontal coils (1321, 1322, 1323) and vertical coils (1324, 1325, 1326) are configured in separate forms on the first substrate (1310), thereby minimizing crosstalk and increasing the accuracy of the force torque sensor.

[0142] In addition, a first horizontal coil (1321), a second horizontal coil (1322), and a third horizontal coil (1323) may be provided as horizontal coils (1321, 1322, 1323), and a first vertical coil (1324), a second vertical coil (1325), and a third vertical coil (1326) may be provided as vertical coils (1324, 1325, 1326).

[0143] In addition, the inductance sensors (not shown) according to the second embodiment may include a first inductance sensor (not shown) including a first horizontal coil (1321) and a first capacitor (not shown), a second inductance sensor (not shown) including a second horizontal coil (1322) and a second capacitor (not shown), a third inductance sensor (not shown) including a third horizontal coil (1323) and a third capacitor (not shown), a fourth inductance sensor (not shown) including a first vertical coil (1324) and a fourth capacitor (not shown), a fifth inductance sensor (not shown) including a second vertical coil (1325) and a fifth capacitor (not shown), and a sixth inductance sensor (not shown) including a third vertical coil (1326) and a sixth capacitor (not shown).

[0144] Here, when three first inductance modulation units (1222a, 1223a, 1224a) are arranged at 120-degree intervals with the center portion (1221) of the screen member (1220) as the center, the first horizontal coil (1321), the second horizontal coil (1322), and the third horizontal coil (1323) can be arranged at 120-degree intervals with the center of the first substrate (1310) as the center. In addition, when three second inductance modulation units (1222b, 1223b, 1224b) are arranged at 120-degree intervals with respect to the center portion (1221) of the screen member (1220), the first vertical coil (1324), the second vertical coil (1325), and the third vertical coil (1326) can be arranged at 120-degree intervals with respect to the center of the first substrate (1310).

[0145] In addition, when the first inductance modulation units (1222a, 1223a, 1224a) and the second inductance modulation units (1222b, 1223b, 1224b) are alternately arranged at 60-degree intervals, the first horizontal coil (1321), the first vertical coil (1324), the second horizontal coil (1322), the second vertical coil (1325), the third horizontal coil (1323), and the third vertical coil (1326) can be sequentially arranged at 60-degree intervals. As the first inductance modulation units (1222a, 1223a, 1224a), the second inductance modulation units (1222b, 1223b, 1224b), the horizontal coils (1321, 1322, 1323), and the vertical coils (1324, 1325, 1326) are arranged as described above, the inductance sensors can more accurately measure the intensity and direction of external force.

[0146] Additionally, a connector portion (1340) for connecting to the circuit configuration of the second sensing substrate (1300B) may be provided on the first substrate (1310).

[0147] In addition, the first substrate (1310) may have first support structure coupling through holes (H110, H111, H112) formed at regular intervals in the vertical direction for coupling with the first support structure (1400A). For example, the first support structure coupling through holes (H110, H111, H112) may be formed at 120-degree intervals. Here, screws (not shown) may be fastened to the first substrate coupling screw holes (h120, h121, h122) of the first support structure (1400A) through the first support structure coupling through holes (H110, H111, H112) from the upper side of the first substrate (1310), respectively.

[0148] The second sensing substrate (1300B) may be positioned below the first sensing substrate (1300A), and may have the remaining circuit configurations except for the coils (1321, 1322, 1323, 1324, 1325, 1326) arranged on the second substrate (1320). For example, capacitors including a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, and a fifth capacitor may be arranged on the second substrate (1320), and at least one inductance change meter (not shown) connected to LC circuits including the coils (1321, 1322, 1323, 1324, 1325, 1326) and capacitors may be arranged. Additionally, a communication unit (not shown), an inertial measurement unit (not shown), and a data processing unit (not shown) may be further configured on the second substrate (1320).

[0149] In addition, the second substrate (1320) may have vertical second support structure coupling through holes (H116, H117, H118) formed at regular intervals for coupling with the second support structure (1400B). For example, the second support structure coupling through holes (H116, H117, H118) may be formed at 120-degree intervals. Here, screws (not shown) may be fastened to the second substrate coupling screw holes (h123, h124, h125) of the second support structure (1400B) through the second support structure coupling through holes (H116, H117, H118) from the upper side of the second substrate (1320), respectively.

[0150] When the coils (1321, 1322, 1323, 1324, 1325, 1326) and the remaining circuit configuration are distributed on the first sensing substrate (1300A) and the second sensing substrate (1300B) as described above, the influence of the change in inductance of the coils (1321, 1322, 1323, 1324, 1325, 1326) due to the change in position of the screen member (1220) on other circuit configurations can be minimized. Accordingly, the accuracy of force torque measurement can be improved.

[0151] In addition, although not shown in the drawing, the circuit configuration including the coils (1321, 1322, 1323, 1324, 1325, 1326) described in the second embodiment may all be configured on a single substrate. In addition, the sensing substrate may be provided in various configurations without being limited thereto.

[0152] Additionally, according to the second embodiment, the support structure may include a first support structure (1400A) and a second support structure (1400B).

[0153] The first support structure (1400A) may be formed in a ring shape with a constant thickness, and may have vertical variable structure coupling through holes (H113, H114, H115) and first substrate coupling screw holes (h120, h121, h122) formed at constant intervals along the ring shape. For example, the variable structure coupling through holes (H113, H114, H115) and the first substrate coupling screw holes (h120, h121, h122) may be formed at 120-degree intervals.

[0154] The second support structure (1400B) may be provided as a cylindrical structure having an open top and a closed bottom, and may have vertical variable structure coupling screw holes (h126, h127, h128) and second substrate coupling screw holes (h121, h122, h123) formed at regular intervals along the inner surface of the cylindrical shape. For example, the variable structure coupling screw holes (h126, h127, h128) and the second substrate coupling screw holes (h121, h122, h123) may be formed at 120-degree intervals.

[0155] Hereinafter, a 6-axis force torque detection method based on inductance measurement according to the present invention will be described with reference to FIG. 11.

[0156] Step S10 is a step in which an external force is applied to a 6-axis force torque detection device (1) based on inductance measurement according to the present invention and the external force is transmitted to a variable structure (200).

[0157] Step S20 is a step in which the spring member (210) of the variable structure (200) is deformed by an external force and its position changes.

[0158] Step S30 is a step in which at least six inductance sensors (320, 330, 340, 350, 360, 370) arranged at different locations each detect a change in inductance according to deformation of the spring member (210).

[0159] Step S40 is a step of calculating the displacement of the spring member (210) by using the inductance change detected by the inductance sensors (320, 330, 340, 350, 360, 370) in the data processing unit (393).

[0160] Step S50 is a step of calculating a six-axis force torque by calculating the magnitude and direction of an external force applied to a spring member (210) using the displacement of the spring member (210) in the data processing unit (393).

[0161] As described above, according to the 6-axis force torque detection device and 6-axis force torque detection method according to the present invention, the intensity and direction of an external force can be measured using a change in inductance.

[0162] Additionally, it is possible to provide higher force torque measurement precision through an inductance change meter that measures inductance change using the resonant frequency change of an LC circuit, which is composed of an integrated circuit (IC) with 24-bit resolution.

[0163] Additionally, since six inductance sensors are arranged on a single substrate, force torque measurement is possible with just one device, which saves time and cost in manufacturing and managing the force torque measurement device and increases space efficiency.

[0164] In addition, a non-contact measurement method is provided in which a predetermined distance is formed between a variable structure that is deformed and changes position by an external force and an inductance sensor, thereby improving the durability and shock resistance of a six-axis force torque device.

[0165] Additionally, it can minimize crosstalk and improve the accuracy of force torque measurements.

[0166] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single entity may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0167] Therefore, the idea of ​​the present invention should not be limited to the embodiments described above, and all things that are modified equally or equivalently to the following claims as well as the claims are considered to fall within the scope of the idea of ​​the present invention.

[0168]

[0169] - Explanation of the symbol -

[0170] 1: 6-axis force torque detection device according to the first embodiment

[0171] 100: Cover structure

[0172] 200: Variable Structure

[0173] 210: Spring member

[0174] 213, 214, 215: Beam section

[0175] 213-1, 214-1, 215-1: First inductance modulation unit

[0176] 213-2, 214-2, 215-2: Second inductance modulation unit

[0177] 220: Variable structure frame

[0178] 300: Sensing substrate

[0179] 310: Substrate

[0180] 320,330,340,350,360,370: Inductance sensor

[0181] 321,331,341,351,361,371: Coil

[0182] 322,332,342,352,362,372: Capacitors

[0183] 381,382: Inductance change meter

[0184] 391: Communication Unit

[0185] 392: Inertial Measurement Unit

[0186] 393: Data Processing Unit

[0187] 400: Support structure

[0188] 1000: 6-axis force torque detection device according to the second embodiment

[0189] 1100: Cover structure

[0190] 1200: Variable Structure

[0191] 1210: Spring member

[0192] 1220: Screen absent

[0193] 1212,1213,1214: Wings

[0194] 1222a, 1223a, 1224a: First inductance modulation unit

[0195] 1222b, 1223b, 1224b: Second inductance modulation unit

[0196] 1230: Variable Structure Frame

[0197] 1240: Absence of support

[0198] 1300A, 1300B: Sensing board

[0199] 1321,1322,1323: Horizontal coil

[0200] 1324,1325,1326: Vertical coil

[0201] 1400A, 1400B: Support structure

Claims

1. A variable structure that elastically changes due to an external force, causing a change in inductance in an inductor including a nearby coil; At least six inductance sensors positioned at different locations to detect changes in inductance of the inductor due to deformation of the variable structure; A sensing substrate including the above inductance sensors and a support structure supporting the variable structure, A six-axis force torque sensing device based on inductance measurement.

2. In paragraph 1, The above variable structure is coupled to the upper side of the sensing substrate at a predetermined interval so as to maintain a non-contact state with the sensing substrate. A six-axis force torque sensing device based on inductance measurement.

3. In paragraph 1, The above inductance sensors, An LC circuit including a coil and a capacitor acting as the inductor; and An inductance change measuring device that measures the inductance change of the coil by using the resonant frequency change of the LC circuit; A six-axis force torque sensing device based on inductance measurement.

4. In paragraph 3, A data processing unit that calculates the displacement of the variable structure from the inductance change measured through the inductance sensors and calculates the strength and direction of the external force applied to the variable structure; A communication unit capable of data communication with the outside; and An inertial measurement unit for measuring acceleration and angular velocity, including an accelerometer and a gyroscope; further comprising: A six-axis force torque sensing device based on inductance measurement.

5. In paragraph 3, The above inductance sensors include a first inductance sensor, a second inductance sensor, a third inductance sensor, a fourth inductance sensor, a fifth inductance sensor, and a sixth inductance sensor, The first coil of the first inductance sensor, the second coil of the second inductance sensor, and the third coil of the third inductance sensor are arranged at 120-degree equal intervals in the center of the sensing substrate, and the vertical component of the external force applied to the variable structure is measured using the inductance change detected through the first coil, the second coil, and the third coil. The fourth coil of the fourth inductance sensor, the fifth coil of the fifth inductance sensor, and the sixth coil of the sixth inductance sensor are arranged at 120-degree intervals at the edge of the sensing substrate, and the horizontal component of the external force applied to the variable structure is measured using the inductance change detected through the fourth coil, the fifth coil, and the sixth coil. The first coil and the fourth coil, the second coil and the fifth coil, and the third coil and the fourth coil are each paired and arranged adjacent to each other. A six-axis force torque sensing device based on inductance measurement.

6. In paragraph 5, The above variable structure includes a spring member that elastically changes by an external force and causes a change in inductance in the inductor, The above spring member includes three beam parts extending radially in a horizontal direction from the center and arranged at 120-degree intervals, The variable structure is coupled to the support structure so that the beam sections are respectively positioned above the first coil and the fourth coil, the second coil and the fifth coil, the third coil and the sixth coil. A six-axis force torque sensing device based on inductance measurement.

7. In paragraph 6, Each of the above beam sections is formed with a first inductance modulation section and a second inductance modulation section, The first inductance modulation section is formed in a round shape at the connection portion between the beam section and the central portion of the variable structure, and is positioned above the first coil, the second coil, and the third coil, so as to change the inductance of the first coil, the second coil, and the third coil, respectively. The second inductance modulation unit is formed in a shape that protrudes sharply in a horizontal direction so as to be perpendicular to the longitudinal direction of the beam unit and is adjacent to the outer side of the first inductance modulation unit, and the sharp end of the second inductance modulation unit is positioned above the fourth coil, the fifth coil, and the sixth coil to change the inductance of the fourth coil, the fifth coil, and the sixth coil, respectively. A six-axis force torque sensing device based on inductance measurement.

8. In paragraph 3, The above inductance sensors include a first inductance sensor, a second inductance sensor, a third inductance sensor, a fourth inductance sensor, a fifth inductance sensor, and a sixth inductance sensor, The first horizontal coil of the first inductance sensor, the second horizontal coil of the second inductance sensor, and the third horizontal coil of the third inductance sensor are arranged at 120-degree equal intervals with the coil surfaces parallel to the sensing substrate, and the vertical component of the external force applied to the variable structure is measured using the inductance change detected through the first horizontal coil, the second horizontal coil, and the third horizontal coil. The first vertical coil of the fourth inductance sensor, the second vertical coil of the fifth inductance sensor, and the third vertical coil of the sixth inductance sensor are arranged at 120-degree equal intervals with the coil planes being perpendicular to the sensing substrate, and the horizontal component of the external force applied to the variable structure is measured using the inductance change detected through the first vertical coil, the second vertical coil, and the third vertical coil. The first horizontal coil, the first vertical coil, the second horizontal coil, the second vertical coil, the third horizontal coil, and the third vertical coil are sequentially arranged at 60-degree intervals. A six-axis force torque sensing device based on inductance measurement.

9. In paragraph 8 The above variable structure includes a spring member that elastically changes by an external force and a screen member that causes an inductance change in the inductor, The above screen member includes three wing parts extending horizontally radially from the center and arranged at 120-degree intervals, Each of the above wing sections is formed with a first inductance modulation section and a second inductance modulation section, The first inductance modulation section is formed in a cylindrical shape on the lower side of the wing sections and is positioned above the first horizontal coil, the second horizontal coil, and the third horizontal coil, and changes the inductance of the first horizontal coil, the second horizontal coil, and the third horizontal coil, respectively. The second inductance modulation section is formed in a plate shape on the lower side of the wing sections, and is positioned above the first vertical coil, the second vertical coil, and the third vertical coil, and changes the inductance of the first vertical coil, the second vertical coil, and the third vertical coil, respectively. A six-axis force torque sensing device based on inductance measurement.

10. In paragraph 3 The sensing substrate includes a first sensing substrate and a second sensing substrate arranged vertically, The coil is arranged on the first sensing substrate to detect a change in inductance according to deformation of the variable structure, The circuit configuration of the sensing substrate including the capacitor and the inductance change measuring device is arranged on the second sensing substrate. A six-axis force torque sensing device based on inductance measurement.

11. A step in which an external force is applied to a variable structure that elastically changes due to an external force and causes a change in inductance in an inductor including a surrounding coil, causing deformation; A step of detecting a change in the inductance of the inductor caused by deformation of the variable structure by at least six inductance sensors arranged at different locations; A step of calculating the displacement of the variable structure by using the inductance change detected by the inductance sensors in the data processing unit; and A step of calculating the magnitude and direction of an external force applied to the variable structure by using the displacement of the variable structure in the data processing unit; including; A six-axis force torque detection method based on inductance measurement.

12. In paragraph 11, The above inductance sensors include an LC circuit including a coil and a capacitor connected to the coil, and an inductance change measuring device connected to the LC circuit and measuring an inductance change of the coil using a change in the resonant frequency of the LC circuit. The step of calculating the magnitude and direction of the external force is to calculate the displacement of the variable structure from the inductance change measured by the inductance change measuring device, and to calculate the magnitude and direction of the external force applied to the variable structure. A six-axis force torque detection method based on inductance measurement.

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