JP2008126331A - Structure of finger of robot hand, force feeling sensor, and robot hand - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect an external force applied to the finger pad at the fingertip of a robot hand by a multi-axis force sensor. <P>SOLUTION: The finger tip portion 10 of the robot hand comprises a multi-axis force sensor 5 for detecting a force or a moment applied to a column shape force transmitting body 53, a membrane member 1 which is arranged such that its surface is nearly perpendicular to the central axis (z-axis) of the force transmitting body 53, and the surface on the side opposite to the force transmitting body 53 serves as the finger pad surface, and a plate shape z-axis force transmitting plate 3 which is located between the membrane member 1 and the force transmitting body 53 such that its surface is nearly perpendicular to the z-axis, and is nearly parallel with the surface of the membrane member 1, and can move only in the direction in parallel with the z-axis. The finger tip portion is configured such that when the external force parallel to the z-axis is applied to the finger pad surface, the force transmitting body 53 is pressed by the z-axis force transmitting plate 3 to be pressed by the membrane member 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a finger structure of a robot hand and a force sensor device suitable for detecting an external force acting on the finger pad surface of the robot hand.

  For example, in order to properly adjust the gripping force of the robot hand when gripping an object by the robot hand, it is necessary to detect an external force acting on the robot hand. Therefore, a multi-axis force sensor is built in the fingertip portion of the robot hand. For example, Patent Document 1 discloses a fingertip structure of a robot hand incorporating a triaxial force sensor.

  Here, the multi-axis force sensor is a sensor that can detect at least forces or moments in two or more directions perpendicular to each other. A typical structure of a multi-axis force sensor is a structure in which a columnar force transmission body is provided on a flexible diaphragm. Such a multi-axis force sensor utilizes the deformation of the diaphragm caused by the force acting on the force transmission body for measuring the force (see, for example, Patent Documents 2 to 4).

  As an example, the structure of a multi-axis force sensor disclosed in Patent Document 2 is shown in FIG. A multi-axis force sensor 70 shown in FIG. 6 includes a columnar force transmission body 72 provided on a flexible diaphragm 71, and a sensor substrate 73 on a surface opposite to the surface on which the force transmission body 72 of the diaphragm 71 is provided. Is a fixed structure. A piezoresistive element 74 is formed on the sensor substrate 73. With such a structure, the diaphragm 71 is deformed by the force acting on the force transmitting body 72, the force acts on the sensor substrate 73 due to the deformation of the diaphragm 71, and the resistance change of the piezoresistive element 74 is caused by the force acting on the sensor substrate 73. Is caused. For this reason, the force acting on the force transmission body 72 can be measured by detecting the resistance change of the piezoresistive element 74. In this specification, as shown in FIG. 3, the direction along the central axis of the columnar force transmission body 72 is defined as the z-axis direction, and the other two axes orthogonal to the z-axis are the x-axis and the y-axis. It is defined as Further, the definition of the coordinate axes is applied to other multi-axis force sensors mentioned in this specification unless otherwise specified.

Typical examples of the multi-axis force sensor are a six-axis force sensor and a three-axis force sensor. The six-axis force sensor is a sensor that can independently detect a total of six components including forces Fx, Fy, and Fz in three axial directions orthogonal to each other and moments Mx, My, and Mz about the axes of these three axes. On the other hand, the triaxial force sensor is a sensor that detects a total of three components of the uniaxial force Fz and the biaxial moments Mx and My orthogonal to the force detection axis, or the triaxial force Fx orthogonal to each other. , Fy, and Fz.
JP 2005-88096 A Japanese Patent No. 2746298 JP 2001-311671 A JP 2001-108541 A

  As shown in FIG. 4 of Patent Document 1, the fingertip portion of the conventional robot hand is such that the center axis of the columnar force transmission body of the multi-axis force sensor, that is, the z-axis is from the first finger joint that supports the fingertip portion. The multi-axis force sensor is arranged along the direction (hereinafter referred to as the fingertip longitudinal direction) perpendicular to the fingertip side surface (hereinafter referred to as the fingertip surface) of the fingertip portion and toward the tip of the fingertip portion. The structure is adopted. Therefore, in the fingertip portion having such a structure, an external force applied perpendicularly to the finger pad surface is detected by the multi-axis force sensor as a force or moment in the x-axis direction or the y-axis direction. This external force acting perpendicularly to the finger pad surface is a major component of the pressing force by the object in contact with the finger pad surface, so it is required to detect this external force accurately, especially when the object is gripped by a robot hand. It is done.

  For example, when the sensor provided at the fingertip portion is a three-axis force sensor that detects a force in the z-axis direction acting on a columnar force transmission body and a moment around the x-axis and the y-axis, The external force in the vertical direction is detected as a moment component around the x axis or the y axis. That is, since the magnitude of the moment detected by the three-axis force sensor changes depending on which position on the finger pad surface the external force acts on, it is difficult to accurately detect the external force acting on the finger pad surface.

  For example, even when the sensor provided at the fingertip portion is a six-axis force sensor, depending on which position on the finger pad surface the external force acts as long as the central axis of the force transmission body is disposed along the fingertip longitudinal direction. The magnitudes of the force and moment detected by the 6-axis force sensor change, and it is difficult to accurately detect an external force acting perpendicularly to the finger pad surface.

  In addition, when the multi-axis force sensor is arranged at the fingertip portion so that the z-axis of the multi-axis force sensor is along the direction perpendicular to the finger pad surface, the range in which the external force applied perpendicular to the finger pad surface can be accurately detected is There is a problem that it is limited to a part of. Specifically, it is limited to a region of the finger pad surface that substantially faces the tip surface of the force transmission body.

  The present invention has been made in consideration of the above-described problems, and a finger structure of a robot hand and a force sensor device capable of accurately detecting an external force acting on the finger pad surface of the robot hand with a multi-axis force sensor. And it aims at providing a robot hand.

  The finger structure of the robot hand according to the first aspect of the present invention includes a multi-axis force sensor that detects a force or moment acting on a columnar force transmission body, and a surface that is substantially perpendicular to the central axis of the force transmission body. A membrane member disposed in a direction and having a surface on the side not directed to the force transmission body as a finger pad surface, and the membrane member in a direction substantially perpendicular to the central axis and substantially parallel to the surface of the membrane member And a plate-like member that is disposed between the force transmission body and displaceable only in a direction parallel to the central axis, and an external force parallel to the central axis acts on the finger pad surface In addition, the force transmission body is configured to be pressed by the plate member pressed by the membrane member. In the embodiment of the invention described later, the membrane member 1 corresponds to the membrane member, and the z-axis force transmission plate 3 corresponds to the plate member.

  Since the finger structure of the robot hand according to the first aspect is a structure in which the multi-axis force sensor is arranged so that the z-axis that is the central axis of the force transmission body is perpendicular to the finger pad surface, The external force acting perpendicularly to can be measured as a force in the z-axis direction. For this reason, the external force acting on the finger pad surface can be accurately measured. Furthermore, it has the structure where the plate-shaped member by which the displacement direction was restrict | limited to the z-axis direction was arrange | positioned between the force transmission body and the film | membrane member. For this reason, even when an external force is applied to a region other than the region of the finger pad surface that is substantially opposed to the distal end surface of the force transmission body, this can be detected by the multiaxial axial force sensor.

  According to a second aspect of the present invention, the finger structure of the robot hand according to the first aspect includes a hollow cylindrical wall portion, one end extending from the wall portion, and the other end connected to the force transmission body. A fixing member that has at least one beam and that fixes the membrane member and the wall portion so that one end of a hollow cylinder formed by the wall portion is closed by the membrane member. . Further, the plate-like member is located in a hollow cylinder formed by the wall portion, and is arranged to be displaceable along the central axis direction without interfering with the fixing member. In the embodiment of the invention described later, the xy axial force transmission frame 2 corresponds to the fixing member.

  According to the second aspect, a component acting on the finger pad surface and parallel to the finger pad surface is transmitted to the multi-axis force sensor via the fixing member. For this reason, the frictional force between the object gripped by the robot hand and the finger pad surface can be directly detected by the multi-axis axial force sensor.

  According to a third aspect of the present invention, in the finger structure of the robot hand according to the first or second aspect, the wall portion and the force transmission body are connected by at least two beams, The angle formed is substantially a right angle. Thereby, the measurement error of the direction and magnitude of the force parallel to the finger pad surface caused by the twist of the beam or the twist of the force transmission body can be suppressed.

  A force sensor device according to a fourth aspect of the present invention includes a multi-axis force sensor that detects a force or moment acting on a columnar force transmission body, and a direction in which a surface is substantially perpendicular to a central axis of the force transmission body. And a plate-like member disposed so as to be displaceable only in a direction parallel to the central axis, and an external force parallel to the central axis acts on the first member. The force transmission body is configured to be pressed by the first member.

  The force sensor device according to the fourth aspect has a structure in which the multi-axis force sensor is arranged so that the z-axis, which is the central axis of the force transmission body, is perpendicular to the membrane member. An external force acting vertically can be measured as a force in the z-axis direction. For this reason, the force which acts on the surface of a film | membrane member can be measured correctly. Furthermore, the first member whose displacement direction is limited to the z-axis direction is disposed between the force transmission body and the membrane member. For this reason, even when an external force acts outside the region of the surface of the membrane member that is substantially opposed to the tip surface of the force transmission body, this can be detected by the multiaxial axial force sensor. Therefore, the external force acting on the finger pad surface or palm surface can be accurately measured by incorporating the force sensor device in the robot hand with the membrane member exposed as at least part of the finger pad surface or palm surface. it can.

  According to a fifth aspect of the present invention, in the force sensor device according to the fourth aspect, the plate-like member is positioned between the force transmitting body and the surface thereof in a direction substantially perpendicular to the central axis. The membrane member, the hollow cylindrical wall portion, and at least one beam having one end extending from the wall portion and the other end connected to the force transmission body, the wall portion It further includes a fixing member in which the edge of the membrane member and the wall portion are fixed so that one end of the hollow cylinder to be formed is closed by the membrane member. Further, the plate-like member is located in a hollow cylinder formed by the wall portion, and is arranged to be displaceable along the central axis direction without interfering with the fixing member.

  According to the fifth aspect, a component acting on the membrane member and parallel to the surface of the membrane member is transmitted to the multi-axis force sensor via the fixed member. For this reason, the force acting in parallel with the surface of the membrane member can be directly detected by the multiaxial axial force sensor.

  A sixth aspect of the present invention is a robot hand comprising the force sensor device according to the fifth aspect, wherein the membrane member is exposed as at least a part of a finger pad surface or a palm surface.

  According to the present invention, it is possible to provide a finger structure of a robot hand, a force sensor device, and a robot hand capable of accurately detecting an external force acting on the finger pad surface of the fingertip portion of the robot hand with a multi-axis force sensor.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description will be omitted as necessary for the sake of clarity.

  The fingertip portion 10 according to the present embodiment is a link member arranged at the end of each finger link in a robot hand having a plurality of finger links. Below, the structure of the fingertip part 10 is demonstrated using FIG. 1 thru | or FIG. FIG. 1 is a perspective view showing an appearance of a fingertip portion 10 according to the present embodiment. FIG. 2 is a plan view of the fingertip portion 10 as viewed from the finger pad surface side. 2, in order to clarify the internal structure of the fingertip portion 10, the membrane member 1 and the z-axis force transmission plate 3 are not shown. FIG. 3 is a cross-sectional view of the fingertip portion 10 and shows a cross section taken along line AA of FIG. 4 is a cross-sectional view of the fingertip portion 10 and shows a cross section taken along line BB of FIG.

  As shown in FIGS. 1, 3 and 4, a flexible membrane member 1 is provided on the finger pad side surface of the fingertip portion 10. The edge of the membrane member 1 is bonded and fixed to the xy axial force transmission frame 2. Since the robot hand having the fingertip portion 10 performs an operation such as gripping an object, a high static friction coefficient is required on the surface of the film member 1. For this reason, a material having a high friction coefficient is preferably used for the film member 1. Alternatively, embossing may be performed to increase the static friction coefficient of the surface of the membrane member 1 on the finger pad side.

  As will be described in detail later, the force Fz in the direction perpendicular to the finger pad surface acting on the membrane member 1 is triaxial through the membrane member 1 pressed toward the finger back side and the z-axis force transmission plate 3. It is transmitted to the force sensor 5. For this reason, the membrane member 1 is preferably a flexible member. In addition, it is good also as a structure which force acts on the z-axis force transmission board 3 because the film | membrane member 1 elastically deforms with force Fz irrespective of the bending deformation of the film | membrane member 1. FIG. In this case, the membrane member 1 and the z-axis force transmission plate 3 may be in surface contact with each other when no external force is applied to the finger pad surface of the membrane member 1.

  On the other hand, the forces Fx and Fy in the direction parallel to the finger pad surface of the external force acting on the membrane member 1 are pulled by the membrane member 1 by the forces Fx and Fy, so that the three-axis force sensor is transmitted via the xy-axis force transmission frame 2. 5 is transmitted. Therefore, the longitudinal elastic modulus of the membrane member 1 is preferably large so that force transmission to the xy-axis force transmission frame 2 by the tension of the membrane member 1 can be performed accurately.

  The xy axial force transmission frame 2 is a member for transmitting parallel forces Fx and Fy acting on the finger pad surface of the fingertip portion 1, that is, the membrane member 1, to the triaxial force sensor 5. As shown in FIGS. 2 to 4, the xy-axis force transmission frame 2 includes a wall portion 21, x-axis beams 22a and 22b, and y-axis beams 23a and 23b. The wall portion 21 is formed in a hollow cylindrical shape on the outer periphery of the xy axial force transmission frame 2. The membrane member 1 is bonded and fixed to the end of the wall portion 21 on the finger pad side.

  The x-axis transmission beams 22a and 22b are beam members that are provided along the x-axis direction, that is, the fingertip longitudinal direction. The x-axis transmission beams 22 a and 22 b extend from the wall portion 21 and are connected to a columnar force transmission body 53 included in the triaxial force sensor 5. The y-axis transmission beams 23a and 23b are beam members provided along the y-axis direction. The y-axis transmission beams 23 a and b also extend from the wall portion 21 and are connected to a columnar force transmission body 53 included in the triaxial force sensor 5.

  The z-axis force transmission plate 3 is a member for transmitting a force Fz in a direction perpendicular to the finger pad surface of the fingertip portion 1, that is, the finger pad surface acting on the membrane member 1, to the three-axis force sensor 5. In FIG. 2, the z-axis force transmission plate 3 is indicated by a dotted line. As shown in FIG. 2, the z-axis force transmission plate 3 is disposed inside a hollow cylinder formed by the wall portion 21 included in the xy-axis force transmission frame 2. 3 and 4, when viewed in the z-axis direction, the z-axis force transmission plate 3 has the force transmission body 53, the x-axis beams 22a and 22b, the y-axis beams 23a and 23b, the membrane member 1, and the like. Located between. The z-axis force transmission plate 3 is provided so as to be displaceable along the z-axis. Specifically, the guide column 4 is inserted into each of the four recesses 31 provided in the z-axis force transmission plate 3, and the z-axis force transmission plate 3 can slide along the four guide columns 4. It is configured.

  The four guide columns extend from the fingertip part frame 6 and are provided in parallel to the z-axis. With such a configuration, the displaceable direction of the z-axis force transmission plate 3 is limited to the z-axis direction. The z-axis force transmission plate 3 and the force transmission body 53 may be in surface contact with no external force acting on the membrane member 1 or may be arranged to face each other with a gap.

  The triaxial force sensor 5 is a sensor that detects a force in the z-axis direction acting on the force transmission body 53 and a moment in the x-axis direction and the y-axis direction. As shown in FIGS. 2 to 4, the triaxial force sensor 5 is arranged such that the z axis of the triaxial force sensor 5, that is, the central axis of the force transmission body 53 is perpendicular to the finger pad surface.

  The triaxial force sensor 5 includes a displacement member 51, a sensor substrate 54, and a sensor housing 55. As shown in FIGS. 2 and 3, a circular diaphragm 52 is formed at the center of the displacement member 51, and a cylindrical force transmission body 53 is formed at the center of the diaphragm 53. The sensor board 54 is provided with a detection element (not shown) such as a resistance element or a variable capacitance element for detecting mechanical strain of the sensor board 54. That is, the detection principle of the three-axis force sensor 5 shown in the present embodiment is that the diaphragm portion 52 is deformed by an external force acting on the force transmission body 53, and the force acts on the sensor substrate 54 due to the deformation of the diaphragm portion 52. A force acting on the sensor substrate 54 is detected by a detection element (not shown) included in the sensor substrate 54. A displacement member 52 is fixed to the sensor housing 55, and a sensor substrate 54 is accommodated inside the sensor housing 55. The sensor housing 55 is fixed to the fingertip frame 6.

  The fingertip part frame 6 is disposed on the finger back side of the fingertip part 10 and supports the four guide columns 4 and the three-axis force sensor 5. A finger first joint portion 7 is formed on the proximal end side of the fingertip portion frame 6. The fingertip portion 10 is connected to a finger link of the robot hand by the first finger joint portion 7.

  Next, how the external force acting on the finger pad surface of the fingertip portion 10 is transmitted to the triaxial force sensor 5 will be described with reference to FIG. FIG. 5A is a cross-sectional view taken along line AA in FIG. 2 and shows a state when a force Fz in the z-axis direction perpendicular to the finger pad surface acts on the finger pad surface of the fingertip portion 10. FIG. 5B is a cross-sectional view taken along line AA in FIG. 2 and shows a state when a force Fx in the x-axis direction parallel to the finger pad surface acts on the finger pad surface of the fingertip portion 10. .

  As shown in FIG. 5A, when the force Fz is applied, the membrane member 1 is bent and deformed, and the membrane member 1 pushed down in the finger back side (−z direction) comes into contact with the z-axis force transmission plate 3. Thus, the force Fz is transmitted from the membrane member 1 to the z-axis force transmission plate 3. Then, the z-axis force transmission plate 3 whose displacement direction is limited to the z-axis direction by the guide support 4 is pushed down toward the finger back side along the z-axis. Thereby, the force transmission body 53 is pressed in the z-axis direction by the pushed-down z-axis force transmission plate 3, so that the force Fz is detected by the three-axis force sensor 5.

  As described above, the fingertip portion 10 according to the present embodiment has a structure in which the three-axis force sensor 5 is arranged so that the z-axis that is the central axis of the force transmission body 53 is perpendicular to the finger pad surface. The external force acting perpendicularly to the finger pad surface can be measured as a force in the z-axis direction. For this reason, the external force acting on the finger pad surface can be accurately measured.

  Even when the position where the force Fz acts on the finger pad surface is different from the position shown in FIG. 5A, the force Fz is transmitted to the force transmission body 53 by the z-axis force transmission plate 3 being pushed down. The That is, the fingertip portion 10 is not only provided with the triaxial force sensor 5 so that the z-axis that is the central axis of the force transmission body 53 is perpendicular to the finger pad surface, but also the force transmission body 53 and the membrane member 1 The z-axis force transmission plate 3 whose displacement direction is limited to the z-axis direction is disposed between the two. For this reason, even when the force Fz is applied to a region other than the region facing the distal end surface of the force transmission body 53 on the finger pad surface of the fingertip portion 10, this can be detected by the triaxial force sensor 5.

  On the other hand, when the force Fx in the x-axis direction as shown in FIG. 5B acts on the finger pad surface, the membrane member 1 is pulled downward in the figure by the force Fx, and the xy axial force is transmitted by the tension of the membrane member 1. The fingertip end side of the wall portion 21 of the frame 2 is pulled toward the finger pad side. By the movement of the wall portion 21, the force transmission body 53 connected by the xy-axis force transmission frame 2 and the x-axis beams 22a and 22b is operated, and the force Fx is a triaxial force sensor 53 as a moment My around the y axis. Detected. Similarly to the case where the force Fx described above is applied, when a force Fy in the y-axis direction parallel to the finger pad surface is applied to the finger pad surface of the fingertip portion 10, the force Fy is a three-axis as a moment Mx around the x axis. It is detected by the force sensor 53. That is, the fingertip portion 10 directly detects an external force acting in parallel with the finger pad surface such as a frictional force between the membrane member 1 and an object in contact with the membrane member 1 by the triaxial force sensor 5 via the xy axial force transmission frame 2. can do.

  In the embodiment of the invention described above, the configuration in which the fingertip portion 10 includes the triaxial force sensor 5 that detects the force Fz and the moments Mx and My has been described. However, the fingertip portion 10 may include a triaxial force sensor or a six-axis force sensor that detects forces Fx, Fy, and Fz in three axial directions orthogonal to each other, instead of the triaxial force sensor 5.

  Moreover, the internal structure of the three-axis force sensor 5 in the above-described embodiment is an example. Many commercializations of multi-axis force sensors having a columnar force transmission body and detecting a force or moment acting on the force transmission body have already been performed. It goes without saying that various structures employed by these products can be applied to the multi-axis force sensor built in the fingertip portion 10.

  Moreover, the structure which connects the xy axis | shaft transmission frame 2 and the force transmission body 53 which the fingertip part 10 has mentioned above is an example. That is, the structure in which the force parallel to the finger pad surface acting on the membrane member 1 is transmitted to the force transmitting body 53 of the three-axis force sensor 5 by the x-axis transmission beams 22a and b and the y-axis transmission beams 23a and b is an example. is there. The xy-axis transmission frame 2 and the force transmission body 53 may be configured to transmit a force parallel to the finger pad surface to the force transmission body 53 without interfering with the z-axis force transmission plate 3. Therefore, the wall portion 21 and the force transmission body 53 may be connected by a part of the x-axis transmission beams 22a and b and the y-axis transmission beams 23a and b. Further, the wall portion 21 and the force transmission body 53 may be connected by more beams. Further, the wall portion 21 and the force transmission body 53 may be connected by a beam not parallel to the x-axis or the y-axis. However, in order to accurately measure the direction and magnitude of the force parallel to the finger pad surface, at least two beams orthogonal to each other, for example, the x-axis beam 22a and the y-axis beam 23a, and the wall portion 21 and the force transmission body 53 are used. It is desirable to connect Thereby, the measurement error of the direction and magnitude of the force parallel to the finger pad surface caused by the twist of the beam or the twist of the force transmission body 53 can be suppressed.

  Moreover, in embodiment of the invention mentioned above, the example which applies this invention to the fingertip part located in the terminal of the finger link which a robot hand has was shown. However, the structure of the fingertip part 10 described above may be applied to other parts where detection of external force is required, such as a link arranged on the proximal end side of the fingertip part in the finger link and the palm part of the robot hand. . Furthermore, the structure of the fingertip unit 10 is not limited to a robot hand, and can be widely applied as a force sensor device for measuring a force sense.

  Furthermore, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention described above.

It is an external appearance perspective view of the fingertip part of the robot hand concerning this invention. It is a top view of the fingertip part of the robot hand concerning the present invention. It is sectional drawing of the fingertip part of the robot hand concerning this invention. It is sectional drawing of the fingertip part of the robot hand concerning this invention. It is sectional drawing when the force of a z-axis direction and a x-axis direction acts on a fingertip part. It is a figure which shows an example of the structure of a multi-axis force sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fingertip part 1 Membrane member 2 xy-axis force transmission frame 21 Wall part 22 x-axis beam 23 y-axis beam 3 z-axis force transmission plate 31 Recessed part 4 Guide post 5 Triaxial force sensor 51 Displacement member 52 Diaphragm part 53 Force transmission body 54 Sensor board 55 Sensor housing 6 Fingertip frame 7 Finger first joint

Claims (8)

A multi-axis force sensor for detecting a force or moment acting on a columnar force transmission body;
A membrane member whose surface is arranged in a direction substantially perpendicular to the central axis of the force transmission body, and whose surface is not directed to the force transmission body as a finger pad surface;
The surface is positioned between the membrane member and the force transmitting body in a direction that is substantially perpendicular to the central axis and substantially parallel to the surface of the membrane member, and is disposed so as to be displaceable only in a direction parallel to the central axis. A plate-shaped member,
A finger structure of a robot hand configured such that, when an external force parallel to the central axis acts on the finger pad surface, the force transmission body is pressed by the plate-like member pressed by the membrane member. The hollow cylindrical wall part and at least one beam having one end extending from the wall part and the other end connected to the force transmission body, and one end of the hollow cylinder formed by the wall part is the membrane member The film member and the wall portion are further fixed so as to be closed by the fixing member,
2. The robot hand according to claim 1, wherein the plate-like member is located in a hollow cylinder formed by the wall portion and is arranged to be displaceable along the central axis direction without interfering with the fixing member. Finger structure.   The finger structure of the robot hand according to claim 2, wherein the wall portion and the force transmission body are connected by at least two beams, and an angle formed by the two beams is substantially a right angle. A multi-axis force sensor for detecting a force or moment acting on a columnar force transmission body;
A plate-like member that is disposed so as to be displaceable only in a direction parallel to the central axis, facing the force transmitting body in a direction in which the surface is substantially perpendicular to the central axis of the force transmitting body,
A force sensor device configured to press the force transmission body by the plate-like member when an external force parallel to the central axis acts on the plate-like member. A film member disposed such that the plate-like member is positioned between the force transmission body and the surface in a direction substantially perpendicular to the central axis;
The hollow cylindrical wall part and at least one beam having one end extending from the wall part and the other end connected to the force transmission body, and one end of the hollow cylinder formed by the wall part is the membrane member A fixing member in which the edge of the membrane member and the wall portion are fixed so as to be closed by
5. The force sensor according to claim 4, wherein the plate-like member is positioned in a hollow cylinder formed by the wall portion, and is displaceable along the central axis direction without interfering with the fixing member. apparatus.   The force sensor device according to claim 5, wherein the wall portion and the force transmission body are connected by at least two beams, and an angle formed by the two beams is substantially a right angle.   7. A finger structure of a robot hand comprising the force sensor device according to claim 5 or 6, wherein the membrane member is exposed as a finger pad surface.   A robot hand comprising the force sensor device according to claim 5, wherein the membrane member is exposed as at least a part of a finger pad surface or a palm surface.