Force-torque sensor and robot

Abstract

The present embodiment relates to a force-torque sensor comprising: a lower case; an upper case disposed on the lower case; a ball disposed between the lower case and the upper case; a coupling member for movably coupling the upper case with respect to the lower case; a magnet disposed on one of the lower case or the upper case; and a Hall sensor disposed on the other of the lower case or the upper case.

Description

Force-torque sensors and robots

[0001] The present embodiment relates to a force-torque sensor.

[0002] Robots are used in a variety of fields, including industry, medicine, service, and other fields, and their scope of application is constantly expanding. To improve the performance and ensure safety of robotic systems, accurate monitoring and control of robot movements are essential. In particular, the forces and torques generated when a robot interacts with its environment or handles objects are crucial information.

[0003] Conventional robot sensor technology has primarily focused on detecting motion states such as position, velocity, and acceleration. However, forces and torques play a crucial role in providing information about robot interactions and the working environment. Force-torque sensors are essential for robots to safely grasp and manipulate objects and respond to their environment. Furthermore, these sensors can be utilized to improve robot efficiency and prevent malfunctions.

[0004] Conventional force-torque sensors cannot separate the applied external force into the forces of each axis. Instead, they receive input simultaneously and decompose the forces. This causes crosstalk noise to be mixed into the detection values ​​for each axis. In particular, noise increases when the Z-axis and torque forces are mixed.

[0005] (Patent Document 1) KR 10-2023-0123723 A

[0006] The present embodiment seeks to provide a force-torque sensor capable of measuring z-axis force and torque force separately.

[0007] Through this, we aim to improve robot control and work processes.

[0008] A force-torque sensor according to the present embodiment may include a lower case; an upper case disposed on the lower case; a ball disposed between the lower case and the upper case; a coupling member movably coupling the upper case to the lower case; a magnet disposed on one of the lower case and the upper case; and a Hall sensor disposed on the other of the lower case and the upper case.

[0009] Each of the lower case and the upper case includes a hole, and the connecting member includes a bolt including a head portion and a body portion, and a nut connected to the body portion, the body portion of the bolt passes through the hole of the lower case and the hole of the upper case, and the head portion and the nut of the bolt can be arranged on opposite sides with the lower case and the upper case interposed therebetween.

[0010] The head portion of the bolt and each of the bolts may be formed larger than the hole of the lower case and the hole of the upper case so that they cannot pass through the hole of the lower case and the hole of the upper case.

[0011] One of the holes of the lower case and the holes of the upper case may be a long hole formed in the roll direction, and the other of the holes of the lower case and the holes of the upper case may be a hole of a size corresponding to the body portion of the bolt.

[0012] The lower case includes a column portion that protrudes from the lower case toward the upper case and includes a rail, the upper case includes a column portion that protrudes from the upper case toward the lower case and includes a rail, and the ball can be disposed between the rail of the lower case and the rail of the upper case.

[0013] The above ball includes a first ball, a second ball, and a third ball disposed between the first ball and the second ball, and the diameter of the third ball may be larger than the diameters of each of the first ball and the second ball.

[0014] At least one of the rails of the lower case and the rails of the upper case may include a groove that is sunken into the rail and in which the third ball is placed.

[0015] The above force-torque sensor may include a sealing member disposed between the lower case and the upper case.

[0016] The force-torque sensor may include a substrate at least partially disposed between the lower case and the upper case, and the Hall sensor may be disposed on the substrate.

[0017] The magnet may include a first magnet and a second magnet arranged on opposite sides with respect to the center of the lower case, and a third magnet and a fourth magnet arranged on opposite sides with respect to the center of the lower case, and the Hall sensor may include a first Hall sensor that detects the first magnet, a second Hall sensor that detects the second magnet, a third Hall sensor that detects the third magnet, and a fourth Hall sensor that detects the fourth magnet.

[0018] The force-torque sensor may include an elastic member including a first coupling portion coupled to the lower case or the upper case, a second coupling portion coupled to the coupling member, and a connecting portion connecting the first coupling portion and the second coupling portion.

[0019] The force-torque sensor may include a coil spring disposed between the lower case and the upper case.

[0020] The force-torque sensor may include a yoke disposed between the lower case and the upper case and subjected to a force from the magnet.

[0021] The upper case can be moved in the z-axis direction, yaw direction, pitch direction, and roll direction relative to the lower case by an external force.

[0022] The robot according to the present embodiment may include the force-torque sensor.

[0023] The force-torque sensor according to this embodiment can measure Z-axis force and torque force separately. This minimizes the influence of noise due to crosstalk on the detection values ​​for each axis. In other words, the measurement accuracy of the force-torque sensor can be improved.

[0024] Figure 1 is a perspective view of a force-torque sensor according to the present embodiment.

[0025] Figure 2 is a plan view of a force-torque sensor according to the present embodiment.

[0026] Fig. 3 is a bottom perspective view of a force-torque sensor according to the present embodiment with the lower case omitted.

[0027] FIG. 4 is a perspective view illustrating the upper case and related configuration of a force-torque sensor according to the present embodiment.

[0028] Fig. 5 is a plan view and a partially enlarged view of the upper case of the force-torque sensor according to the present embodiment.

[0029] Fig. 6 is a side view of a force-torque sensor according to the present embodiment.

[0030] Fig. 7 is a bottom perspective view of a force-torque sensor according to the present embodiment.

[0031] Fig. 8 is a perspective view of a force-torque sensor according to the present embodiment with the upper case omitted.

[0032] Fig. 9 is an enlarged perspective view of the magnet and Hall sensor and related components of the force-torque sensor according to the present embodiment.

[0033] Fig. 10 is a plan view and a partially enlarged view of the lower case of the force-torque sensor according to the present embodiment.

[0034] Fig. 11 is an exploded perspective view of a force-torque sensor according to the present embodiment.

[0035] Fig. 12 is a cross-sectional view taken along line AA of Fig. 1.

[0036] Fig. 13 is a drawing showing an example of a coupling member of a force-torque sensor according to the present embodiment.

[0037] Fig. 14 is a cross-sectional view taken from BB in Fig. 1.

[0038] Fig. 15 is a cross-sectional view of a force-torque sensor according to a modified example.

[0039] Fig. 16 is an enlarged cross-sectional perspective view of the magnet and Hall sensor and related components of the force-torque sensor according to the present embodiment.

[0040] Figure 17 is a cross-sectional perspective view of a force-torque sensor according to a modified example.

[0041] Fig. 18 is a drawing for explaining the roll direction operation of the force-torque sensor according to the present embodiment. More specifically, Fig. 18 (a) is a drawing illustrating a case where the upper case moves counterclockwise in the roll direction, and Fig. 18 (b) is a drawing illustrating a case where the upper case moves clockwise in the roll direction.

[0042] Fig. 19 is a drawing for explaining the z-axis direction operation of the force-torque sensor according to the present embodiment. More specifically, Fig. 19 (a) is a drawing illustrating a case where the upper case moves upward in the z-axis direction, and Fig. 19 (b) is a drawing illustrating a case where the upper case moves downward in the z-axis direction.

[0043] FIGS. 20 and 21 are diagrams for explaining the yaw and pitch direction operation of the force-torque sensor according to the present embodiment. More specifically, FIG. 20 is a diagram showing four types of forces (a, b, c, d) applied to the upper case (120). FIG. 21 (a) is a cross-sectional view showing the appearance when the force shown as a in FIG. 20 is applied, FIG. 21 (b) is a cross-sectional view showing the appearance when the force shown as c in FIG. 20 is applied, FIG. 21 (c) is a cross-sectional view showing the appearance when the force shown as b in FIG. 20 is applied, and FIG. 21 (d) is a cross-sectional view showing the appearance when the force shown as d in FIG. 20 is applied.

[0044] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0045] However, the technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of ​​the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

[0046] In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which the present invention belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0047] Additionally, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention.

[0048] In this specification, the singular may also include the plural unless specifically stated otherwise in the phrase, and when it is described as “A and / or at least one (or more) of B, C”, it may include one or more of all combinations that can be combined with A, B, C.

[0049] Additionally, in describing components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and are not intended to limit the nature, order, or sequence of the components.

[0050] And, when a component is described as being 'connected', 'coupled', or 'connected' to another component, it may include not only cases where the component is 'connected', 'coupled', or 'connected' directly to the other component, but also cases where the component is 'connected', 'coupled', or 'connected' by another component between the component and the other component.

[0051] Additionally, when described as being formed or arranged "above" or "below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Furthermore, when expressed as "above" or "below," the meaning may include not only the upward direction but also the downward direction based on one component.

[0052] Hereinafter, one of the z-axis, x-axis, and y-axis may be referred to as the “first axis,” the other as the “second axis,” and the other as the “third axis.”

[0053] Hereinafter, one of the roll direction, yaw direction, and pitch direction may be referred to as a “first circumferential direction,” another may be referred to as a “second circumferential direction,” and another may be referred to as a “third circumferential direction.” In addition, the roll direction, yaw direction, and pitch direction may be referred to as “first to third directions.”

[0054]

[0055] Below, the configuration of a force-torque sensor according to the present embodiment and a modified example is described with reference to the drawings.

[0056] Fig. 1 is a perspective view of a force-torque sensor according to the present embodiment. Fig. 2 is a plan view of a force-torque sensor according to the present embodiment. Fig. 3 is a bottom perspective view of a force-torque sensor according to the present embodiment with the lower case omitted. Fig. 4 is a perspective view illustrating an upper case and related components of a force-torque sensor according to the present embodiment. Fig. 5 is a top view and a partially enlarged view of an upper case of a force-torque sensor according to the present embodiment. Fig. 6 is a side view of a force-torque sensor according to the present embodiment. Fig. 7 is a bottom perspective view of a force-torque sensor according to the present embodiment. Fig. 8 is a perspective view of a force-torque sensor according to the present embodiment with the upper case omitted. Fig. 9 is an enlarged perspective view illustrating a magnet, a Hall sensor, and related components of a force-torque sensor according to the present embodiment. Fig. 10 is a top view and a partially enlarged view of a lower case of a force-torque sensor according to the present embodiment. Fig. 11 is an exploded perspective view of a force-torque sensor according to the present embodiment. Fig. 12 is a cross-sectional view taken along line AA of Fig. 1. Fig. 13 is a drawing showing an example of a coupling member of a force-torque sensor according to the present embodiment. Fig. 14 is a cross-sectional view taken along line BB of Fig. 1. Fig. 16 is an enlarged cross-sectional perspective view of a magnet, a Hall sensor, and related components of a force-torque sensor according to the present embodiment.

[0057] A force-torque sensor can be used to detect and measure forces and torques applied to a robot in real time. A force-torque sensor can detect a force applied to the force-torque sensor. A force-torque sensor can measure a force applied to the force-torque sensor. A force-torque sensor can detect a torque applied to the force-torque sensor. A force-torque sensor can measure a torque applied to the force-torque sensor. A force-torque sensor can be a six-axis force-torque sensor. A force-torque sensor can detect and measure forces in six directions, namely the x-axis, y-axis, z-axis, yaw, pitch, and roll directions. A force-torque sensor can be a finger sensor of a robot.

[0058] The force-torque sensor may include a case (100). The case (100) may form an exterior. The case (100) may form a space inside. A magnet (210) and a Hall sensor (220) may be arranged inside the case (100).

[0059] A force-torque sensor may include a fixed part. The fixed part may be a part that is relatively fixed when the moving part moves, as distinguished from the moving part.

[0060] The case (100) may include a lower case (110). The fixed part may include the lower case (110). The lower case (110) may be positioned below the upper case (120). The lower case (110) may be positioned opposite the upper case (120).

[0061] The lower case (110) may include a hole (111). The hole (111) may be a screw hole. A body portion (412) of a bolt (410) may be arranged in the hole (111). A coupling member (400) may pass through the hole (111). The coupling member (400) may be coupled to the hole (111). The coupling member (400) may be arranged to be movable within the hole (111). The hole (111) may be an elongated hole. As illustrated in FIG. 10, the hole (111) may be formed such that a first width in the roll direction (see b of FIG. 10) is larger than a second width in a direction perpendicular to the roll direction (see a of FIG. 10). The direction perpendicular to the roll direction may be a radial direction. The hole (111) may be an elongated hole formed in the roll direction.

[0062] The lower case (110) may include a pillar portion (112). The pillar portion (112) may protrude from the lower case (110) toward the upper case (120). The pillar portion (112) may include a rail (113). A ball (300) may be arranged on the pillar portion (112). The pillar portion (112) of the lower case (110) may be arranged on the opposite side of the pillar portion (122) of the upper case (120) with respect to the ball (300).

[0063] The lower case (110) may include a rail (113). The rail (113) may be a ball rail on which a ball (300) is placed. The rail (113) may be placed in the z-axis direction. The rail (113) may extend in the z-axis direction. A ball (300) may be placed on the rail (113). The rail (113) may be formed as a V-groove. The rail (113) may include a groove. The groove of the rail (113) may be formed to have a size corresponding to that of the ball (300).

[0064] The lower case (110) may include a hole (114). The hole (114) may be a substrate through hole. The leg portion (232) of the substrate (230) may be extended outward through the hole (114). A portion of the substrate (230) may be arranged to pass through the hole (114).

[0065] The lower case (110) may include a protrusion (115). The protrusion (115) may have a shape that protrudes downward. The lower case (110) may include a groove (116). The groove (116) may be formed on an opposite side of the protrusion (115). The groove (116) and the protrusion (115) may be formed to correspond to each other. The groove (116) may be formed on an opposite side of the protrusion (115). The lower case (110) may be formed of a plate material, and the groove (116) corresponding to the opposite side of the protrusion (115) may be formed. A column (112) and a ball (300) may be arranged in the groove (116).

[0066] The lower case (110) may include a protrusion (118). The protrusion (118) may have an upwardly protruding shape. The lower case (110) may include a groove (117). The groove (117) may be formed on an opposite side of the protrusion (118). The groove (117) and the protrusion (118) may be formed to correspond to each other. The groove (117) may be formed on an opposite side of the protrusion (118). The lower case (110) may be formed of a plate material, and the groove (117) corresponding to the opposite side of the protrusion (118) may be formed. A part of the joining member (400) may be placed in the groove (117). A nut (420) may be placed in the groove (117). Alternatively, a head portion (411) of a bolt (410) may be placed in the groove (117).

[0067] The lower case (110) may include a protrusion (119). The protrusion (119) may be coupled with an elastic member (500). The protrusion (119) may be inserted into a hole of the elastic member (500) and coupled thereto.

[0068] The force-torque sensor may include a moving part. The moving part may be a part that moves in response to an external force. That is, the moving part can move relative to the fixed part when an external force is applied to the force-torque sensor.

[0069] The case (100) may include an upper case (120). The moving part may include the upper case (120). The upper case (120) may be placed on the lower case (110). The upper case (120) may be placed on the lower case (110). The upper case (120) may be movably placed on the lower case (110). The upper case (120) may move relative to the lower case (110) when an external force is applied. The upper case (120) may move in the z-axis direction, the yaw direction, the pitch direction, and the roll direction relative to the lower case (110) by the external force.

[0070] The upper case (120) may include a hole (121). The hole (121) may be a screw hole. A body portion (412) of a bolt (410) may be arranged in the hole (111). A coupling member (400) may pass through the hole (121). The coupling member (400) may be coupled to the hole (121). The coupling member (400) may be arranged to be movable within the hole (121). The hole (121) may be an elongated hole. As illustrated in FIG. 5, the hole (121) may be formed such that a first width in the roll direction (see b of FIG. 5) is larger than a second width in a direction perpendicular to the roll direction (see a of FIG. 5). The direction perpendicular to the roll direction may be a radial direction. The hole (121) may be an elongated hole formed in the roll direction.

[0071] In this embodiment, one of the holes (111) of the lower case (110) and the holes (121) of the upper case (120) may be long holes formed in the roll direction, and the other of the holes (111) of the lower case (110) and the holes (121) of the upper case (120) may be holes of a size corresponding to the body portion (412) of the bolt (410). That is, the connecting member (400) may be fixed to one of the upper case (120) and the lower case (110) and may be movable with respect to the other.

[0072] The upper case (120) may include a pillar portion (122). The pillar portion (122) may protrude from the upper case (120) toward the lower case (110). The pillar portion (122) may include a rail (123). A ball (300) may be arranged on the pillar portion (122). The pillar portion (122) of the upper case (120) may be arranged on the opposite side of the pillar portion (112) of the lower case (110) with respect to the ball (300).

[0073] The upper case (120) may include a rail (123). The rail (123) may be a ball rail on which a ball (300) is placed. The rail (123) may be placed in the z-axis direction. The rail (123) may extend in the z-axis direction. A ball (300) may be placed on the rail (123). The rail (123) may be formed as a V-groove. The rail (123) may include a groove. The groove of the rail (123) may be formed to have a size corresponding to that of the ball (300).

[0074] The upper case (120) may include a groove (124). The groove (124) may be a ball receiving groove. The groove (124) may be formed in a rail (123) of the upper case (120). The groove (124) may be recessed relative to the rail (123). A third ball (330) may be placed in the groove (124). Alternatively, the groove (124) may be formed in a rail (113) of the lower case (110).

[0075] The upper case (120) may include a protrusion (125). The protrusion (125) may have an upwardly protruding shape. The upper case (120) may include a groove (126). The groove (126) may be formed on an opposite side of the protrusion (125). The groove (126) and the protrusion (125) may be formed to correspond to each other. The groove (126) may be formed on an opposite side of the protrusion (125). The upper case (120) may be formed of a plate material, and the groove (126) corresponding to the opposite side of the protrusion (125) may be formed. A column (122) and a ball (300) may be arranged in the groove (126).

[0076] The upper case (120) may include a protrusion (128). The protrusion (128) may have a shape that protrudes downward. The upper case (120) may include a groove (127). The groove (127) may be formed on an opposite side of the protrusion (128). The groove (127) and the protrusion (128) may be formed to correspond to each other. The groove (127) may be formed on an opposite side of the protrusion (128). The upper case (120) may be formed of a plate material, and the groove (127) corresponding to the opposite side of the protrusion (128) may be formed. A part of the connecting member (400) may be placed in the groove (127). The head (411) of the bolt (410) may be placed in the groove (127). Alternatively, a nut (420) may be placed in the groove (127).

[0077] The force-torque sensor may include a sealing member (130). The sealing member (130) may be positioned to prevent foreign matter from entering between the upper case (120) and the lower case (110). The sealing member (130) may be positioned between the upper case (120) and the lower case (110). The sealing member (130) may be an O-ring. The sealing member (130) may have elasticity. The sealing member (130) may be formed of a deformable material. The sealing member (130) may be deformed by movement of the upper case (120). The sealing member (130) may seal the space between the upper case (120) and the lower case (110).

[0078] The force-torque sensor may include a magnet (210). The magnet (210) may be disposed in the upper case (120). The magnet (210) may be magnetic. The magnet (210) may be a two-pole magnet. Alternatively, the magnet (210) may be a four-pole magnet.

[0079] The magnet (210) may include a plurality of magnets. The magnet (210) may include four magnets. The magnet (210) may include first to fourth magnets (211, 212, 213, 214). The magnet (210) may include a first magnet (211) and a second magnet (212) which are arranged on opposite sides with respect to the center of the lower case (110), and a third magnet (213) and a fourth magnet (214) which are arranged on opposite sides with respect to the center of the lower case (110).

[0080] The force-torque sensor may include a sensor. The sensor may include, for example, a Hall sensor (220). The force-torque sensor may include a Hall sensor (220). The Hall sensor (220) may be disposed in the lower case (110). The Hall sensor (220) may be disposed on a substrate (230). The Hall sensor (220) may be electrically connected to the substrate (230). The Hall sensor (220) may be coupled to the substrate (230).

[0081] The Hall sensor (220) can detect the magnet (210). The Hall sensor (220) can detect the magnetic field of the magnet (210). The Hall sensor (220) can detect the strength of the magnetic field of the magnet (210) and thereby detect a change in the position of the magnet (210). The Hall sensor (220) can be arranged to face the magnet (210). The Hall sensor (220) can face the magnet (210). The Hall sensor (220) can be arranged at a position corresponding to the magnet (210). The Hall sensor (220) can overlap the magnet (210) in the radial direction.

[0082] The Hall sensor (220) may include a plurality of Hall sensors. The Hall sensor (220) may include four Hall sensors. The Hall sensor (220) may include first to fourth Hall sensors (221, 222, 223, 224). The Hall sensor (220) may include a first Hall sensor (221) that detects a first magnet (211), a second Hall sensor (222) that detects a second magnet (212), a third Hall sensor (223) that detects a third magnet (213), and a fourth Hall sensor (224) that detects a fourth magnet (214). The first Hall sensor (221) and the second Hall sensor (222) may be arranged on opposite sides with respect to the center of the lower case (110). The third hall sensor (223) and the fourth hall sensor (224) can be placed on opposite sides of the center of the lower case (110).

[0083] As a variation, the magnet (210) may be placed in the lower case (110) and the Hall sensor (220) may be placed in the upper case (120).

[0084] The force-torque sensor may include a substrate (230). At least a portion of the substrate (230) may be disposed between the lower case (110) and the upper case (120). The substrate (230) may be disposed on the lower case (110). The substrate (230) may be disposed on the lower case (110). The substrate (230) may be disposed so as not to move even when the upper case (120) moves.

[0085] The substrate (230) may include a mounting portion (231). A Hall sensor (220) may be arranged on the mounting portion (231). The substrate (230) may include a leg portion (232). The leg portion (232) may extend from the mounting portion (231). The leg portion (232) may extend to the outside of the case (100). The leg portion (232) may be arranged under the lower case (110). The leg portion (232) may be connected to an external power source and a control unit.

[0086] The force-torque sensor may include a guide member. The guide member may guide the movement of the moving member relative to the fixed member.

[0087] The force-torque sensor may include a ball (300). The guide member may include the ball (300). The ball (300) may guide movement of the movable part with respect to the fixed part. The ball (300) may guide movement of the movable part with respect to the fixed part in a specific direction. The ball (300) may guide movement of the upper case (120) with respect to the lower case (110). The ball (300) may be formed of a ceramic ball. The ball (300) may guide movement of the upper case (120) with respect to the lower case (110) in the z-axis direction, the yaw direction, the pitch direction, and the roll direction.

[0088] The ball (300) may be placed between the lower case (110) and the upper case (120). The ball (300) may be placed between the rail (113) of the lower case (110) and the rail (123) of the upper case (120). The ball (300) may be formed in a spherical shape.

[0089] The ball (300) may include a plurality of balls. The ball (300) may include three balls. The ball (300) may include first to third balls (310, 320, 330). The first ball (310) may be a lower ball. The second ball (320) may be an upper ball. The third ball (330) may be a center ball. The ball (300) may include the first ball (310), the second ball (320), and the third ball (330) positioned between the first ball (310) and the second ball (320). The diameter of the third ball (330) may be larger than the diameters of each of the first ball (310) and the second ball (320).

[0090] The force-torque sensor may include a coupling member (400). The coupling member (400) may movably couple the upper case (120) to the lower case (110). The coupling member (400) may be fixed to one of the upper case (120) and the lower case (110) and not fixed to the other. Alternatively, the coupling member (400) may only limit the relative range of movement between the upper case (120) and the lower case (110) and may not be fixed to either member. The coupling member (400) may limit the movement of the upper case (120) relative to the lower case (110) to a preset range.

[0091] The connecting member (400) may include a bolt (410). The bolt (410) may include a head portion (411). The bolt (410) may include a body portion (412). The body portion (412) of the bolt (410) may pass through a hole (111) of the lower case (110) and a hole (121) of the upper case (120). The bolt (410) may include a screw thread (412a).

[0092] The head portion (411) of the bolt (410) may be formed larger than the hole (111) of the lower case (110) and the hole (121) of the upper case (120) so that the bolt (410) cannot pass through the hole (111) of the lower case (110) and the hole (121) of the upper case (120). The bolt (410) may be formed larger than the hole (111) of the lower case (110) and the hole (121) of the upper case (120) so that the bolt (410) cannot pass through the hole (111) of the lower case (110) and the hole (121) of the upper case (120).

[0093] The coupling member (400) may include a nut (420). The nut (420) may be coupled to the body portion (412). The nut (420) may include a screw thread. The nut (420) may be coupled to the screw thread (412a) of the body portion (412).

[0094] The head (411) and nut (420) of the bolt (410) can be placed on opposite sides with the lower case (110) and the upper case (120) interposed therebetween.

[0095] The force-torque sensor may include a restoring member. The restoring member can move the moving part to its original position when the external force acting on the force-torque sensor is removed.

[0096] The force-torque sensor may include a ball pressure member. The ball pressure member may pressurize the ball (300) so that the ball (300) remains in contact with the lower case (110) and the upper case (120) to prevent the ball (300) from moving out of a preset position.

[0097] The force-torque sensor may include an elastic member (500). The restoring member may include an elastic member (500). The ball pressurizing member may include an elastic member (500). The elastic member (500) may move the moving part to its original position when the external force applied thereto disappears. The elastic member (500) may move the upper case (120) to its original position when the external force applied thereto disappears. The elastic member (500) may maintain the pressurized state of the ball (300). The elastic member (500) may include a spring. The elastic member (500) may include a plate spring. The elastic member (500) may include a wire spring. The elastic member (500) may include a coil spring. The elastic member (500) may have elasticity. The elastic member (500) may have elasticity.

[0098] The elastic member (500) can provide a roll direction restoring force to the upper case (120). In addition, the elastic member (500) can provide a yaw direction, a pitch direction, a roll direction, and a z-axis direction restoring force together.

[0099] As a variation, the elastic member (500) may be provided with a separate coil spring that provides a roll direction restoring force to the upper case (120) and provides a yaw direction, a pitch direction, and a z-axis direction restoring force to the upper case (120). The force-torque sensor may include a coil spring. The coil spring may be arranged between the lower case (110) and the upper case (120). One end of the coil spring may be in contact with the lower surface of the upper case (120) and the other end may be arranged on the upper surface of the lower case (110). The coil spring may elastically support the upper case (120) and the lower case (110) in a direction that pushes them apart from each other. A plurality of coil springs may be provided. The coil spring may be arranged to surround the body portion (412) of the coupling member (400).

[0100] The elastic member (500) may include a first coupling portion (510). The first coupling portion (510) may be coupled to the lower case (110). Alternatively, the first coupling portion (510) may be coupled to the upper case (120). The elastic member (500) may include a second coupling portion (520). The second coupling portion (520) may be coupled to the coupling member (400). The elastic member (500) may include a connecting portion (530). The connecting portion (530) may connect the first coupling portion (510) and the second coupling portion (520). The connecting portion (530) may be an elastic portion. The connecting portion (530) may have elasticity. The connecting portion (530) may include a shape that is bent multiple times.

[0101]

[0102] Below, the configuration of a force-torque sensor according to a modified example is described with reference to the drawings.

[0103] Fig. 15 is a cross-sectional view of a force-torque sensor according to a modified example.

[0104] A force-torque sensor according to an alternative embodiment may include a coil spring (600). The coil spring (600) may be positioned between the ball (300) and the upper case (120) and between the ball (300) and the lower case (110). In an alternative embodiment, the groove (124) of the present embodiment may be omitted. The coil spring (600) may pressurize the ball (300) from both sides to maintain the ball (300) at a preset position.

[0105] Figure 17 is a cross-sectional perspective view of a force-torque sensor according to a modified example.

[0106] A force-torque sensor according to an embodiment may include a yoke (700). The yoke (700) may be disposed between the lower case (110) and the upper case (120). The yoke (700) may be subject to an attractive force with a magnet (210). The yoke (700) may provide a restoring force to move the upper case (120) to its original position. The yoke (700) may be disposed on the substrate (230). The yoke (700) may be disposed on the substrate (230) on the opposite side of the Hall sensor (220).

[0107]

[0108] Below, the operation of the force-torque sensor according to the present embodiment is described with reference to the drawings.

[0109] Fig. 18 is a drawing for explaining the roll direction operation of the force-torque sensor according to the present embodiment. More specifically, Fig. 18 (a) is a drawing illustrating a case where the upper case moves counterclockwise in the roll direction, and Fig. 18 (b) is a drawing illustrating a case where the upper case moves clockwise in the roll direction.

[0110] When an external force having a counterclockwise component in the roll direction is applied to the upper case (120) of the force-torque sensor according to the present embodiment, the upper case (120) can be rotated or tilted counterclockwise around the z-axis (see a of FIG. 18).

[0111] When an external force having a clockwise component in the roll direction is applied to the upper case (120) of the force-torque sensor according to the present embodiment, the upper case (120) can be rotated or tilted clockwise around the z-axis (see b of FIG. 18).

[0112] When the upper case (120) moves, the lower case (110) remains fixed, so that the Hall sensor (220) placed in the lower case (110) detects the magnet (210) placed in the upper case (120), and the amount of movement of the upper case (120) can be measured. Through this, the force in the roll direction component of the external force applied to the upper case (120) can be measured.

[0113] Fig. 19 is a drawing for explaining the z-axis direction operation of the force-torque sensor according to the present embodiment. More specifically, Fig. 19 (a) is a drawing illustrating a case where the upper case moves upward in the z-axis direction, and Fig. 19 (b) is a drawing illustrating a case where the upper case moves downward in the z-axis direction.

[0114] When an external force having a z-axis upward component is applied to the upper case (120) of the force-torque sensor according to the present embodiment, the upper case (120) can move in the z-axis upward direction (see a of FIG. 19).

[0115] When an external force having a z-axis downward component is applied to the upper case (120) of the force-torque sensor according to the present embodiment, the upper case (120) can move in the z-axis downward direction (see b of FIG. 19).

[0116] When the upper case (120) moves, the lower case (110) remains fixed, so that the Hall sensor (220) placed in the lower case (110) detects the magnet (210) placed in the upper case (120), and the amount of movement of the upper case (120) in the z-axis direction can be measured. Through this, the z-axis direction component of the external force applied to the upper case (120) can be measured.

[0117] FIGS. 20 and 21 are diagrams for explaining the yaw and pitch direction operation of the force-torque sensor according to the present embodiment. More specifically, FIG. 20 is a diagram showing four types of forces (a, b, c, d) applied to the upper case (120). FIG. 21 (a) is a cross-sectional view showing the appearance when the force shown as a in FIG. 20 is applied, FIG. 21 (b) is a cross-sectional view showing the appearance when the force shown as c in FIG. 20 is applied, FIG. 21 (c) is a cross-sectional view showing the appearance when the force shown as b in FIG. 20 is applied, and FIG. 21 (d) is a cross-sectional view showing the appearance when the force shown as d in FIG. 20 is applied.

[0118] When an external force (see a of FIG. 20) having a component in one direction of the yaw direction is applied to the upper case (120) of the force-torque sensor according to the present embodiment, the upper case (120) can be rotated or tilted in one direction about the x-axis (see a of FIG. 21).

[0119] When an external force (see c of FIG. 20) having a component in the other direction is applied to the upper case (120) of the force-torque sensor according to the present embodiment, the upper case (120) can be rotated or tilted in the other direction around the x-axis (see b of FIG. 21).

[0120] When an external force having a component in one direction of the pitch direction (see b in FIG. 20) is applied to the upper case (120) of the force-torque sensor according to the present embodiment, the upper case (120) can be rotated or tilted in one direction around the y-axis (see c in FIG. 21).

[0121] When an external force (see d of FIG. 20) having a component in the other direction of the pitch direction is applied to the upper case (120) of the force-torque sensor according to the present embodiment, the upper case (120) can be rotated or tilted in the other direction around the y-axis (see d of FIG. 21).

[0122] When the upper case (120) moves, the lower case (110) remains fixed, so that the Hall sensor (220) placed in the lower case (110) detects the magnet (210) placed in the upper case (120), and the amount of movement of the upper case (120) can be measured. Through this, the yaw and pitch direction components of the external force applied to the upper case (120) can be measured.

[0123] Although not illustrated in the drawing, when an external force is applied to shift the upper case (120) in the y-axis direction, it can operate in the same manner as when an external force in the y-direction is applied. In addition, when an external force is applied to shift the upper case (120) in the x-axis direction, it can operate in the same manner as when an external force in the pitch direction is applied. That is, the force-torque sensor according to the present embodiment can detect an external force having an x-axis shift component and an external force having a y-axis shift component.

[0124] The force-torque sensor according to the present embodiment can detect external forces in a total of six axial components: z-axis shift, x-axis shift, y-axis shift, yaw rotation, pitch rotation, and roll rotation.

[0125]

[0126] Below, the configuration of the robot according to this embodiment is described.

[0127] A robot may include a body. The robot may include an arm connected to the body. The arm of the robot may include a gripping portion. The gripping portion may include, for example, a finger shape. The force-torque sensor of the present embodiment may be disposed on the gripping portion of the arm. The arm of the robot may include a joint. The force-torque sensor of the present embodiment may be disposed on a joint of the arm.

[0128]

[0129] Although the embodiments of the present invention have been described with reference to the attached drawings, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical concept or essential features thereof. Therefore, the embodiments described above should be understood to be illustrative in all respects and not restrictive.

Claims

1. Lower case; An upper case placed on the lower case; A ball disposed between the lower case and the upper case; A joining member that movably joins the upper case to the lower case; A magnet disposed in either the lower case or the upper case; and A force-torque sensor comprising a Hall sensor arranged in the other of the lower case and the upper case.

2. In paragraph 1, Each of the lower case and the upper case includes a hole, The above-mentioned connecting member includes a bolt including a head portion and a body portion, and a nut connected to the body portion. The body portion of the above bolt passes through the hole of the lower case and the hole of the upper case, A force-torque sensor in which the head portion of the bolt and the nut are positioned on opposite sides with the lower case and the upper case interposed therebetween.

3. In paragraph 2, A force-torque sensor in which the head of the bolt and each of the bolts are formed larger than the hole of the lower case and the hole of the upper case so that they cannot pass through the hole of the lower case and the hole of the upper case.

4. In paragraph 2, One of the holes of the lower case and the holes of the upper case is a long hole formed in the roll direction, A force-torque sensor wherein the other of the hole of the lower case and the hole of the upper case is a hole of a size corresponding to the body portion of the bolt.

5. In paragraph 1, The lower case includes a pillar portion that protrudes from the lower case toward the upper case and includes a rail, The upper case includes a pillar portion that protrudes from the upper case toward the lower case and includes a rail, The above ball is a force-torque sensor disposed between the rail of the lower case and the rail of the upper case.

6. In paragraph 5, The above ball includes a first ball, a second ball, and a third ball disposed between the first ball and the second ball, A force-torque sensor in which the diameter of the third ball is larger than the diameters of each of the first ball and the second ball.

7. In paragraph 6, A force-torque sensor comprising a groove in which at least one of the rails of the lower case and the rails of the upper case is sunken into the rail and in which the third ball is placed.

8. In paragraph 1, A force-torque sensor including a sealing member disposed between the lower case and the upper case.

9. In paragraph 1, At least a portion of the substrate is disposed between the lower case and the upper case, The above Hall sensor is a force-torque sensor placed on the above substrate.

10. In paragraph 1, The above magnets include a first magnet and a second magnet which are arranged opposite to each other based on the center of the lower case, and a third magnet and a fourth magnet which are arranged opposite to each other based on the center of the lower case. The above Hall sensor is a force-torque sensor including a first Hall sensor that detects the first magnet, a second Hall sensor that detects the second magnet, a third Hall sensor that detects the third magnet, and a fourth Hall sensor that detects the fourth magnet.

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