KR19990016504A - Force / moment sensor - Google Patents

Abstract

The present invention relates to a force / moment sensor for detecting the components of the force in the three-axis direction and the component of the moment rotating about the three axes on a spatial coordinate system composed of X, Y, and Z axes, the inside of the longitudinal direction A cylindrical moving part 2 having a through hole 2a formed therein; A cylindrical cylindrical fixing part (1) positioned in the hollow to maintain a predetermined distance from the inner wall of the moving part (2) and fixed to an external movable supporter; An auxiliary moving part in the form of a rectangular parallelepiped, which is embedded in a space part formed at a position deviated by a predetermined distance from the center in the longitudinal direction of the fixing part 1 to a distance, and is positioned to maintain a predetermined distance from the inner wall of the fixing part 1. (6); contact switches (S1 to S12) which are provided at four equally spaced intervals along the upper and lower outer peripheral surfaces of the fixing part (1), and are respectively provided on the upper and lower surfaces and the left and right sides of the auxiliary moving part (6). And a through shaft (7) for axially connecting the respective components through through holes formed on the same height and on the same axis of the moving portion (2), the fixing portion (1), and the auxiliary moving portion (6), respectively. It is configured to include, wherein the auxiliary moving part (6) moves in conjunction with the movement of the moving part (2), the fixing part (1) can be a little flow within the diameter range of the through hole (1a) By adopting a simpler structure Cost is also a very useful inventions that can detect the forces and moments acting on the outside.

Description

Force / moment sensor

The present invention relates to a force / moment sensor for detecting a force component in the three-axis direction and a component of a moment rotating about the three axes on a spatial coordinate system composed of X, Y, and Z axes. In the state, when the external force acts between the moving means and the fixing means that maintain a certain distance from each other, the relative position change is generated. By detecting the relative position change by a separate sensing means, the force and moment acting from the outside are reversed. It relates to a force / moment sensor that can be detected.

One of the fields of use of the force / moment sensor is teaching work of a robot, and in the past, many methods using a teach pendant have been used to teach the robot. This method is to generate the robot motion in the desired direction by pressing the motion command switch in 6 directions (X-direction translation, X-direction rotation, Y-direction translation, Y-direction, Z-direction translation, Z-direction rotation) located on the teaching box. It was. However, the method of using the teaching box was simple and economical, but it was difficult for the user to recognize three directions of X-Y-Z in space, and thus there was a problem in that the robot motion in the desired direction was accurately generated.

In order to solve this problem, after attaching the force / moment sensor to the body of the robot and moving the robot by pushing or pulling the force and moment sensor by hand, a method of accurately generating the robot motion in the desired direction is used. have. In this case, the force / moment is expressed based on a spatial coordinate system composed of coordinate axes perpendicular to each other, commonly called X, Y, and Z axes.

Although there are various types of force / moment sensors used in the above method, in most cases, the deformation of the sensor caused by an external force and moment is detected by using a strain gauge or the like. I'm using a method to calculate a value. However, the strain-based sensor has a number of problems, and various methods have been devised to solve the problem. Examples of this include US Patent No. 5,490,427 Six Axis Force Sensor Employing Multiple Shear Strain Gages and Korean Patent Publication No. 96-6311. There is a / moment sensor.

U.S. Patent No. 5,490,427 measures strain using only shear strain gauges mounted on an L-shaped or T-shaped leg having at least two arms perpendicular to each other in the longitudinal axis thereof. The main thing is to do. The legs are equipped with at least two shear strain gauges on the arms perpendicular to each other so as to measure forces acting in directions perpendicular to each other. Three or more of the L-shaped or T-shaped legs (leg) is generally implemented in a hollow cylindrical body to form a force sensor. When the shear strain gage output from the arm having the structure described above is transmitted to the digital signal processor, it determines the magnitude and direction of the force / moment applied to the cylindrical body. In addition, the shear strain gauge is mounted in a space formed separately so that it can be mounted, so that the shear strain gauge can be more sensitive to shear strain (shear deformation).

In addition, the force / moment sensor proposed in the Korean Patent Publication No. 96-6311, a circular upper plate connected to the robot arm and a circular lower plate for attaching the work tool and a plurality of bridges interconnecting both plates And a surface having the same curvature as the curvature of the center hole on the outer surface that is soft to the sensor central axis of the bridge element and the outer surface that is inclined with respect to the central axis. By providing the same, the resistance change caused by the temperature of the distortion gauge mounted on the constitution wall surface of the center hole and the concave circular arc surface becomes equal, so that the degree of compensation due to temperature can be improved.

However, the conventional force / moment sensor based on the deformation of the sensor by the external force configured as described above can detect the force / moment acting on the sensor from the outside with a continuous value very accurately, but due to the relatively high price, There was a problem that it is difficult to use universally.

Accordingly, the present invention was made to solve the above problems, and an object thereof is to provide a force / moment sensor capable of detecting force and moment in six directions applied from the outside at a lower cost. Another object of the present invention is to provide a force / moment sensor capable of accurately detecting the direction of a force applied from the outside with a higher precision, and another object of the present invention is to provide a method for detecting a force by using only a minimal sensor. It is an object of the present invention to provide a force / moment sensor capable of detecting force and moment in a direction.

1 is a perspective view showing an embodiment of a force / moment sensor according to the present invention, Figure 2 is a cross-sectional view taken along the line AA of Figure 1, Figure 3 is a cross-sectional view taken along the line BB of Figure 1, Figure 4 is a CC of Figure 1 5 and 6 show the principle of detecting the applied force when the force Fx acts in the X-axis direction or the force Fy acts in the Y-axis direction, respectively, in the embodiment of FIG. (A) shows the initial state before the force is applied from the outside, (b) when the force Fx or the force Fy is applied to the center of the moving part, (c) and (d) the force Fx or the force Fy is moved FIG. 7 illustrates a case where the force is selectively applied only to the upper part or the lower part of the part, and FIG. 7 illustrates the principle of detecting the applied force when the force Fz acts in the Z-axis direction in the embodiment of FIG. The initial state before the force is applied to the moving part 2 from the outside, (b) the force Fz is (C) and (d) show the case where the force Fz is selectively applied only to the right or left side of the moving part, respectively, and FIG. 8 rotates about the X axis in the embodiment of FIG. (1) shows the initial state without moment applied from the outside, and (b) the force Fy is applied simultaneously on the upper and lower sides of the moving part. (C) and (d) show the case where the moment acts as the force Fy is selectively applied only to the upper part or the lower part of the moving part, and FIG. 9 shows the embodiment of FIG. When the moment My rotates about the Y axis acts, the detection principle of the applied moment is shown, respectively, (a) shows the initial state without a moment applied from the outside, and (b) the force Fx guy (C) and (d) show the cases where the moment acts as the force Fx is selectively applied only to the upper or lower part of the moving part, respectively, when the moment is applied simultaneously at the top and the bottom of the part. 1 shows the principle of detecting the moment when the moment Mz rotating about the Z axis is applied to the embodiment of FIG. 1, (a) and (b) show an initial state in which no moment is applied from the outside. And (c) and (d) show the operation of the switch when the moment is applied from the outside, and FIGS. 11 and 12 show the accuracy of the direction of the detected force according to the number of sensors arranged. 13 and 14 show another embodiment of the force / moment sensor according to the present invention, in which the sensing means is provided only on the outer surface of the auxiliary moving part, and FIG. 15 shows the force / moment according to the present invention. Another of the sensor As an example, the sensing means is provided only on the outer surface of the fixing part, (a) is a side cross-sectional view, (b) is a sectional view taken along the line DD of (a), and FIG. 16 is a force / moment sensor according to the present invention. (A) is a side cross-sectional view, (b) is EE line sectional drawing of (a).

Explanation of symbols for main parts of the drawings

1: fixing part 1a: through hole

2: moving part 2a: hollow

3: upper moving part 4: lower moving part

6: auxiliary moving part 7: through shaft

8: upper fixing part 9: lower fixing part

S, S1, S2, S3, ..: Contact Switches

Force / moment sensor according to the present invention for achieving the above object, the moving means is formed through the hollow in the longitudinal direction; Fixing means positioned in the hollow so as to maintain a predetermined distance from the inner wall of the moving means and fixed to an external movable support; A plurality of sensing means provided in the fixing means for detecting a change in relative position with the moving means; Auxiliary moving means positioned on a space portion formed at a predetermined distance from a longitudinal central axis of the fixing means to maintain a predetermined distance from an inner wall of the fixing means; And a plurality of auxiliary sensing means provided on an outer surface of the auxiliary moving means to sense a change in relative position with the fixing means, wherein the moving means moves around the fixing means within the predetermined interval. It is held by the fixing means so that the auxiliary movement means is characterized in that the movement in conjunction with the movement of the movement means, within the range of the predetermined interval formed between the space portion, The moment sensor is characterized in that the plurality of sensing means are arranged at equal intervals to each other in the number of multiples of 4, the force / moment sensor according to the present invention, the fixing means is formed inside the hollow portion of the rectangular parallelepiped It is divided into two parts that can be separated from each other, and the secondary tooth in the form of a cuboid embedded in the hollow part. And a plurality of sensing means are disposed on each side so that the sensing means arranged on each face of the fixing means are symmetrical with each other, and the two sensing means on any one side are the arbitrary means. Another feature is that the virtual planes, including sensing means arranged on each of the planes, are arranged adjacent to the stool on a virtual line following the center of any stool (interface) that forms the plane. Is there.

In the force / moment sensor according to the present invention configured as described above, after the fixing means is fixed to the external movable support, the moving means is pushed and pulled by hand, or the handle is attached to the outer surface of the moving means. When the handle is pushed and pulled, a force or a moment is transmitted to the moving means according to the direction of the applied force, and the moving means and the auxiliary moving means are separated by the predetermined interval according to the direction and position of the transmitted force / moment. The sensing means and the auxiliary detecting means detects a change in relative position of the moving means and the fixing means of the auxiliary moving means in the process.

Since the sensing means and the auxiliary sensing means are arranged to form a virtual XYZ coordinate system that is orthogonal to each other in the force / moment sensor according to the present invention, the force / moment applied to the sensor from the outside is the force / It is to be decomposed into a moment component, a force / moment component in the Y direction and a force / moment component in the Z direction, and then operate the sensing means and the auxiliary sensing means located in the respective component directions.

Therefore, by combining and analyzing the positions of the sensing means and the auxiliary sensing means for which the relative position change is detected, it is possible to calculate the applied force / moment inversely. However, it is detected as a discontinuous value according to the arrangement interval of the sensing means and the auxiliary sensing means.

In this case, since the plurality of sensing means are arranged at equal intervals with the number of multiples of four along the upper and lower outer peripheral surfaces of the fixing means, the direction of the acting force can be detected more finely.

In the above, the case where the sensing means and the auxiliary sensing means are provided on the outer surfaces of the fixing part and the auxiliary moving means has been described, but the sensing means is simply changed relative position of the moving means and the auxiliary moving means with respect to the fixing means. Since the sensing means is provided on the inner side of the moving means, and the auxiliary sensing means is provided on the inner side of the fixing means, where to determine the mounting position is included. Various modifications are possible by one of ordinary skill in the art.

Hereinafter, the configuration and operation of the preferred embodiment of the force / moment sensor according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing an embodiment of a force / moment sensor according to the present invention, Figure 2 is a cross-sectional view taken along line AA of Figure 1, Figure 3 is a cross-sectional view taken along line BB of Figure 1, Figure 4 is a CC of Figure 1 As a cross-sectional view, the force / moment sensor according to the present invention includes a cylindrical moving part 2 having a hollow 2a penetrating therein in a longitudinal direction, as shown in the figure; A cylindrical fixing part (1) positioned in the hollow so as to maintain a predetermined distance from the inner wall of the moving part (2) and fixed to an external movable supporter; A rectangular parallelepiped auxiliary moving part embedded in a space part formed at a position deviated by a predetermined distance outward from the longitudinal central axis of the fixing part 1 and positioned to maintain a predetermined distance from the inner wall of the fixing part 1 ( 6); Four contact switches provided at equal intervals along the upper and lower outer circumferential surfaces of the fixing part 1 and provided on the upper and lower surfaces and the left and right sides of the auxiliary moving part 6, respectively; And a through shaft (7) for axially connecting each of the components through through holes formed on the same height and on the same axis of the moving part (2), the fixing part (1) and the auxiliary moving part (6), respectively. It is configured to include, wherein the auxiliary moving part (6) is supported by each other by the through shaft (7) to move in conjunction with the movement of the moving part (2), the fixing part (1) The moving shaft 2 is held by the through hole 1a formed to have a diameter larger than that of the through shaft 7, so that the through shaft 7 is within the diameter range of the through hole 1a. Some flow is possible.

Since the contact switches S1 to S8 provided on the upper and lower outer circumferential surfaces of the fixing part 1 are arranged at four equal intervals, the virtual lines connecting the contact switches facing each other as shown in FIG. The virtual line connecting S1 and S3, S5 and S7 forms the X axis, and the virtual line connecting S2 and S4, S6 and S8 forms the Y axis. In addition, the contact switches S9 to S12 disposed on the upper and lower surfaces and the left and right surfaces of the auxiliary moving unit 6 are virtual lines connected to the contact switches S10 and S12 provided on the upper and lower surfaces as shown in FIG. In order to form this Z axis, it is arranged in the longitudinal axis direction of the fixing part 1 so as to be orthogonal to the plane including the virtual X axis and Y axis, and the contact switch S1 to the force / moment sensor according to the present invention. Based on the position of S12), it is possible to form a spatial coordinate system composed of X, Y, and Z axes that are perpendicular to each other. Contact switches S9 and S11 respectively provided on the left and right side surfaces of the auxiliary moving part 6 may detect the moment of rotation about an imaginary Z axis formed by the contact switches S10 and S12. It is arrange | positioned to the left and right in the direction perpendicular | vertical to the arrangement | positioning direction of switches S10 and S12.

Fig. 13 is an exploded perspective view showing another embodiment of the force / moment sensor according to the present invention, in which the overall component is configured similarly to the embodiment shown in Fig. 1, wherein the fixing part 1 is at the top height; It is in the form of a rectangular parallelepiped freely separated by the front part 8 and the lower fixing part 9, and the auxiliary moving part 6 is formed in the space part formed by the upper fixing part 8 and the lower fixing part 9. It is built in, but the contact switches are disposed only on each outer surface of the auxiliary moving part (6). The contact switches are provided two on each side so that the contact switches arranged on each face are symmetrical with each other, and two sensing means on any one face are arranged closer to the stool on an imaginary line following the center of the stool facing each other. The virtual surfaces including the sensing means arranged on the respective facing surfaces are orthogonal to each other.

Fig. 14 shows another embodiment of the force / moment sensor according to the present invention shown in Fig. 13, in which four contact switches are arranged on each side of the auxiliary moving means 6 adjacent to each other.

15 shows another embodiment of the force / moment sensor according to the present invention, wherein the moving part 2 is separated into an upper moving part 3 and a lower moving part 4 in which a hollow is formed therein. It is in the form of a free rectangular parallelepiped, and the fixing part 1 is in the shape of a rectangular parallelepiped, and four contact switches S are provided for each outer surface so as to be adjacent to the corners thereof.

Fig. 16 shows another embodiment of the force / moment sensor according to the present invention, and has a rectangular groove formed at equal intervals along the outer circumferential surface of the fixing part 1, and the moving part 2 has the rectangular shape. Protrusions are formed at positions corresponding to the grooves, and each contact surface of the rectangular groove is provided with one contact switch S at a position in contact with the protrusions.

On the other hand, in each of the embodiments, an outer handle may be attached to the outer surface of the moving part 2 so that the user can move more easily, and the relative position of the fixed part 1 and the moving part 2 In order to detect a change, a pressure sensor for outputting a signal according to the magnitude of the pressing force may be used instead of the contact switch.

Hereinafter, the operation of the force / moment sensor according to the present invention configured as described above will be described in detail with reference to the drawings.

First, the force / moment sensor according to the present invention is fixed to a predetermined position on the body of the robot or a space desired by the user using the fixing part 1.

The fixed part 1 maintains a predetermined distance from the moving part 2 and the auxiliary moving part 6 at an initial state, and when the force or moment is applied to a predetermined magnitude from the outside, the moving part is thereby moved. (2) and / or the auxiliary moving part 6 moves in the direction of the fixing part 1, and in this process, the contact switch is operated, which is the force in the X-axis, Y-axis, and Z-axis directions. This will be described in more detail by dividing each case into a case where the moment to rotate around each axis acts as follows.

First, the principle of detecting when a force is applied from the outside to the force / moment sensor according to the present invention will be described. Hereinafter, Fx, Fy, and Fz represent the forces applied in the X-axis, Y-axis, and Z-axis directions, respectively. Denotes a contact switch operated by the contact between the fixed part 1 and the moving part 2 or the auxiliary moving part 6.

Fig. 5 shows the principle of detection when the force Fx acts in the X-axis direction. (A) shows the initial state before the force is applied to the moving part 2 from the outside. Since the auxiliary moving part 6 is omitted in some drawings and a virtual coordinate system is set in the center of the fixing part 1, in the virtual spatial coordinate system made by the contact switches S1 to S12, X As shown in (a) of FIG. 5, the contact switch disposed in the axial direction is disposed on the contact switches of S1 and S3 located on the upper outer circumferential surface of the fixing part 1 and on the lower outer surface of the fixing part 1. Contact switches of S5 and S7.

If the force Fx in the X-axis direction acts on the center portion of the moving part 2, as shown in (b) of FIG. 5, the upper and lower parts of the moving part 2 simultaneously hold the fixed part 1. Direction so as to be in contact with the contact switch S3 and S7 located on the outer surface of the fixed part 1 at the same time, the two switches are operated at the same time, if the force Fx in the X-axis direction is the moving part 2 Independently acting only on the upper or lower portion of, only the S3 contact switch and the S7 contact switch are selectively operated, as shown in (c) and (d) of FIG. 5, respectively.

Further, if the force Fx acts in the opposite direction on the same axis as the force acting in the above case, i.e. in the -X axis direction, in each of the above cases, S1 and S5 are operated simultaneously, or S1 or S5 Only works selectively.

Accordingly, if the contact switch operated after the movement of the moving part 2 is analyzed and calculated in reverse, the direction of the force (+ X axis or -X axis) acting on the moving part 2 from the outside is not required. The position of the force (top, center, bottom) can also be detected.

Fig. 6 shows the principle of detection when the force Fy acts in the Y-axis direction. (A) shows the initial state before the force is applied to the moving part 2 from the outside. When the force Fy is applied to the center of the moving part 2, (c) the force Fy is applied only to the upper part of the moving part 2, (c) the force Fy is applied only to the lower part of the moving part 2 It shows the operation of the contact switch when applied.

As shown in the figure, the principle for detecting the direction and position of the force Fy acting in the Y-axis direction is the same as the detection principle of the force Fx of FIG. 5, except that the contact switch for detecting the fixed portion is The only difference is the contact switches of S2 and S4 disposed on the upper outer peripheral surface of (1) and the contact switches of S6 and S8 disposed on the lower outer peripheral surface of the fixing part 1.

Fig. 7 shows the detection principle when the force Fz acts in the Z-axis direction. In this case, unlike the case where the forces in the X- and Y-axis directions act, the auxiliary moving part 6 is provided. The direction of the force is detected using the contact switches S10 and S12.

In the initial state as shown in FIG. 7A, in which no force is applied from the outside, the force acts simultaneously in the Z direction at the left and right sides of the moving part 2 such that the moving part 2 is fixed to the fixed part 1. When moved upwardly in parallel along the outer circumferential surface of the, the auxiliary moving part (6), which is supported by the through shaft (7) and moves in conjunction with the movement of the moving part (2), also moves together. Accordingly, as shown in (b) of FIG. 7, the contact switch S12 provided at the upper part of the auxiliary moving part 6 is operated by contact with the upper inner wall of the space part formed in the fixing part 1.

If the force Fz acts in the -Z axis direction, the contact switch S10 is operated as the auxiliary moving part 6 moves downward.

Next, the principle of detecting when a moment is applied from the outside to the force / moment sensor according to the present invention will be described. Hereinafter, Mx, My, and Mz represent moments of rotation about an X axis, a Y axis, and a Z axis, respectively.

Fig. 8 shows the principle of detection when the moment Mx rotating about the X axis is applied. (A) shows an initial state in which no moment is applied to the moving part 2 from the outside. For convenience, the auxiliary moving part 6 is omitted in some drawings as in the case of measuring the force, and a virtual coordinate system is set in the center of the fixing part 1. At this time, since the direction of vertically penetrating the ground shown in the drawing is the direction of the X-axis, the moment Mx rotates in the left and right directions on the drawing, and thus, the contact for detecting the moment as shown in FIG. The switch is a contact switch of S2 and S4 disposed on the upper outer circumferential surface of the fixing part 1 and S6 and S8 disposed on the lower outer circumferential surface of the fixing part 1 to form the Y axis.

If the force Fy acts simultaneously in the -Y direction on the upper right side of the moving part 2 and in the + Y direction on the lower left side, the moment to rotate about the + X axis acts on the moving part 2. Accordingly, as shown in (b) of FIG. 8, the upper part of the moving part 2 moves simultaneously to the left side and the lower part to the right side of the moving part 2, so that the S2 and S8 of the fixing part 1 Since the contact with the contact switch at the same time, both switches are operated at the same time, even if the moment in the same direction acts if the force Fy acts in the -Y direction only in the upper portion of the moving part (2), or in the + Y direction only in the lower portion In operation, as shown in FIGS. 8C and 8D, only one of the two contact switches S2 and S8 is operated.

Also, if the force Fy acts in the opposite direction on the same axis as the force Fy acting in the above case, that is, simultaneously in the + Y direction on the upper left side of the moving part 2 and in the -Y direction on the lower right side. Or, in the case of acting in the + Y direction only in the upper left or in the -Y direction only in the lower right, the moment to rotate about the -X axis acts on the moving part 2, accordingly, in each case S4 And S6 are operated simultaneously, or only one of S4 or S6 is selectively operated.

Therefore, if the moving part 2 rotates in the X-axis direction and analyzes the contact switch operated in reverse, the direction of the moment acting on the moving part 2 from the outside (turn left or around the X axis or Right turn) is also able to detect the position (upper, lower) of the force applied at this time.

Fig. 9 shows the principle of detection when the moment My rotating about the Y axis is applied. (A) shows the initial state before the force for acting as a moment from the outside is applied. When the force Fx acts simultaneously on the upper and lower left and right sides of the moving part 2, (c) and (d) show the case where the force Fx acts only on the upper part or the lower part of the moving part 2.

As shown in the figure, the principle for detecting the direction of the moment My rotating about the Y axis is the same as the detection principle of the moment Mx of FIG. 8, except that the moment is detected as the rotation center axes are different from each other. The only difference is that the contact switch is a contact switch of S1 and S3 disposed on the upper outer circumferential surface of the fixing part 1, and a contact switch of S5 and S7 disposed on the lower outer circumferential surface of the fixing part 1. .

FIG. 10 shows the detection principle when the moment Mz rotating about the Z axis is applied. In this case, unlike the case where My and Mx, which are the moments rotating around the X and Y axes, are applied, The direction of the moment is detected using the contact switches S9 and S11 provided in the auxiliary moving part 6.

In the initial state as shown in Fig. 10 (a) (b) in which no force for generating a moment is applied from the outside, when the moment Mz rotating about an imaginary Z axis acts, the moving part 2 It rotates along the outer circumference of the fixing part 1 within the diameter range of the through hole formed in the fixing part 1, and is thus held by the through shaft 7 to be locked by the moving part 2. The auxiliary moving part 6 formed to move in conjunction with the movement moves in the same direction as the rotational direction of the moving part 2, so that the contact switches S9 and S11 are formed on the inner wall of the space part formed in the fixing part 1. It works by coming into contact with it.

That is, as shown in (d) of FIG. 10, when the moment of rotation about the virtual + Z axis (the direction vertically penetrates the ground shown in the drawing) acts, the contact switch S11 is operated. On the contrary, if the moment of rotation about the virtual -Z axis is applied, the contact switch S9 is activated.

In the above embodiment, only the minimum number of four contact switches for determining the X and Y axes of the virtual coordinate system is provided along the upper and lower outer peripheral surfaces of the fixing part 1, but a larger number of contact switches are provided. It can also obtain further by dividing the direction of the force acting on the plane containing the said X axis and the Y axis.

That is, as shown in Fig. 11A, when only four contact switches are arranged at equal intervals on the outside of the fixing part 2, the four contact switches are + X and + Y, respectively. , -X and -Y directions, whereby only one of the contact switches is actuated by a force applied from the outside, it can be detected that the force is applied along the axial direction. As shown in Fig. 2), if two adjacent switches are operated simultaneously, it is possible to detect that a force in the center direction of the two operated switches is applied depending on which switch is operated. do. Therefore, when four contact switches are provided, the direction detection capability of the applied force has an accuracy of 45 °, which is 1/2 of the center angle formed by the adjacent contact switches.

However, as shown in Fig. 12A, when eight contact switches are arranged at equal intervals on the outside of the fixing part 2, each switch can detect the force in the 45 ° direction. As shown in (b) of FIG. 12, when two adjacent switches are operated at the same time, a force having a precision of 22.5 degrees corresponding to 1/2 of 45 degrees, which is the center angle formed by the two operated switches, The direction can be detected.

In general, a large number of contact switches can be used around a fixed part, and when N contact switches are located at evenly spaced intervals, the direction detection resolution of the force acting on the virtual plane including the X axis and the Y axis is ( 180 / N) ˚. Therefore, by constructing the mechanism by increasing the number of contact switches, it is possible to detect the direction of force / moment with higher accuracy.

As described above, the principle of detection of the forces Fx, Fy, Fz applied in the X, Y, Z axis directions and the moments Mx, My, Mz rotating about the axis are described in detail with reference to the accompanying drawings. When the state of the contact switch provided on the outer circumferential surface of the fixing portion 2 as an input and the force and the moment as an output value can be obtained by using a transformation. The conversion may be made in various forms such as conversion formulas and conversion tables so as to detect some or all of the cases in Figs. 5 to 12, and may be obtained by a relationship as shown in the following table, for example.

In this case, a contact switch for detecting a change in relative position between the fixing part 1 and the moving part 2 is provided on the outer circumferential surface of the fixing part 1 and the outer surface of the auxiliary moving part 6. Although the case has been described, it is not a big problem in detecting the direction of force and moment where the contact switch is provided, and as shown in Figure 13 and 14, the auxiliary moving portion embedded in the interior space of the fixing portion It may be provided only on the outer side, and as shown in Fig. 15, the sensor may be formed only by the fixing part and the moving part without providing a separate auxiliary moving part, and then the contact switch may be provided only outside the fixing part.

At this time, the number of contact switches is at least two arranged on one side as shown in Fig. 13, the imaginary faces including the contact switches disposed on the facing sides are arranged to be symmetrical to each other, each facing face When arranged so as to be perpendicular to each other, it is possible to detect both the force in the X, Y and Z axis directions and the direction of the moment rotating about the three axes using the fewest number of contact switches.

In the above description for the convenience of explanation and understanding of the present invention, the shape and arrangement position of each component, etc. have been limited and described, but those skilled in the art to which the present invention pertains the scope of the technical idea of the present invention. It will be possible to make various changes to the present invention without departing from the scope. For example, in the above description, a cylinder-shaped device is described as an example, but a device using a polygonal column may be used, and any sensor capable of detecting a relative position change in the device such as a proximity sensor instead of a contact switch may be used. In the case of using a contact force sensor, not only the direction of the force and the moment but also the magnitude can be detected together. In addition, as described above, the fixed part 1, the moving part 2, and the auxiliary moving part 6 are separated and maintained at predetermined intervals in the initial state, and then a relative position change is detected by detecting a subsequent contact. Instead, the initial state is in contact with each other, but the relative position change is detected by a change in the magnitude of the contact force generated between the fixed part 1, the moving part 2 and the auxiliary moving part 6 later. The force and the moment can also be detected by this.

The force / moment sensor according to the present invention configured and operated as described above is a very useful invention that can detect the direction of force and moment acting from the outside at a low cost by adopting a simpler structure.

Claims (19)

A moving means having a hollow penetrating the inside in the longitudinal direction; Fixing means positioned in the hollow so as to maintain a predetermined distance from the inner wall of the moving means and fixed to an external movable support; And sensing means provided in the fixing means to detect movement of the moving means, wherein the moving means is caught by the fixing means so as to move around the fixing means within a predetermined interval. Force / Moment sensor, characterized in that supported. According to claim 1, wherein the rectangular space portion in the direction of the center axis from the outer circumferential surface of the fixing means are formed at equal intervals along the outer circumferential surface, the moving means is formed with a projection to be inserted into the space portion corresponding to the space portion And the sensing means is provided for each surface of the rectangular space part. According to claim 1, Auxiliary moving means positioned to maintain a predetermined distance from the inner wall of the fixing means on the space portion formed in the fixing means at a predetermined distance from the longitudinal central axis of the fixing means; And a plurality of auxiliary sensing means provided on an outer surface of the auxiliary moving means to sense a relative movement with respect to the fixing means, wherein the auxiliary moving means is within a predetermined interval formed between the space parts. Force / moment sensor, characterized in that the movement in conjunction with the movement of the movement means. The method of claim 3, wherein the moving means and the fixing means is cylindrical, the auxiliary moving means is a rectangular parallelepiped, the space portion is formed in the inward direction of the fixing means, the moving means, the fixing means and the auxiliary moving means Are axially connected to each other through through holes respectively formed on the same axis, and the plurality of sensing means are formed in plural at equal intervals along the upper and lower outer peripheral surfaces of the fixing means, and the auxiliary sensing means is formed through the auxiliary moving means. Force / moment sensor, characterized in that formed on each of the four surfaces except the axis passing surface. The force / moment sensor according to claim 4, wherein the plurality of sensing means are arranged at equal intervals in number of multiples of four. The method of claim 1, wherein the auxiliary movement means in the form of a rectangular parallelepiped moving in conjunction with the movement of the moving means; wherein the fixing means is a hollow portion of the rectangular parallelepiped formed therein, the secondary movement in the hollow portion Force / moment sensor, characterized in that formed into two parts that can be separated from each other so as to embed the means, the plurality of sensing means is provided on the inner surface of the fixing means. According to claim 6, wherein the plurality of sensing means are disposed on each side so that the sensing means arranged on each face of the fixing means are symmetrical with each other and the two sensing means on any one face on the virtual line of the center of the stool A force / moment sensor, which is disposed to be adjacent to a face, wherein virtual faces including four sensing means disposed on each face are orthogonal to each other. The method of claim 6, wherein the plurality of sensing means is disposed on each side of the number of times four times adjacent to the inner edge of the fixing means, characterized in that the distance between the two adjacent sensing means are arranged to be equal to each other Force / moment sensor. The force / moment sensor according to any one of claims 1 to 8, wherein a handle is attached to an outer surface of the moving means. The force / moment sensor according to any one of claims 1 to 8, wherein the sensing means is a contact switch for sensing a contact. The force / moment sensor according to any one of claims 1 to 8, wherein the sensing means is a pressure sensor for outputting a signal according to the magnitude of the pressing force. The force / moment sensor according to any one of claims 1 to 8, wherein the sensing means is a proximity sensor for detecting whether the sensing means is within a predetermined distance. A moving means having a hollow penetrating the inside in the longitudinal direction; Located in the hollow so as to maintain a predetermined distance from the inner wall of the moving means, the structure is divided into two parts that can be separated from each other, the hollow portion of the rectangular parallelepiped formed therein, the fixing means fixed to the external movable support; An auxiliary moving means positioned to maintain a predetermined distance from an inner wall of the hollow part and moving in association with a movement of the moving means; And a plurality of sensing means provided in the auxiliary moving means to sense a relative movement with respect to the fixing means, wherein the moving means and the auxiliary moving means are arranged around the fixing means within a predetermined interval. Force / moment sensor, characterized in that the locking means is supported to be movable. A moving means having a hollow penetrating the inside in the longitudinal direction; Fixing means positioned in the hollow so as to maintain a predetermined distance from the inner wall of the moving means and fixed to an external movable support; And a plurality of sensing means provided in the moving means to detect a relative movement with respect to the fixing means, wherein the moving means is movable around the fixing means within a predetermined interval. Force / moment sensor, characterized in that supported on. 15. The method of claim 14, wherein the auxiliary movement means in the form of a rectangular parallelepiped moving in conjunction with the movement of the moving means; and the fixing means is a hollow portion of the rectangular parallelepiped is formed therein, the secondary movement in the hollow portion Force / moment sensor, characterized in that divided into two parts that can be separated from each other so that the built-in means, the plurality of sensing means is provided on the outer surface of the auxiliary moving means. 16. The apparatus of claim 15, wherein the plurality of sensing means are disposed two on each face such that the sensing means arranged on each face of the auxiliary moving means are symmetrical with each other, and the two sensing means on any one face are connected to the zoom core of the stool. Force / moment sensor, characterized in that arranged on the line adjacent to the stool, the imaginary surfaces including the four sensing means disposed on each of the opposite sides orthogonal to each other. The method of claim 15, wherein the plurality of sensing means is disposed on each side in the number of four times adjacent to the outer edge of the auxiliary movement means, characterized in that the distance between the two adjacent sensing means are arranged to be equal to each other Force / moment sensor. It is divided into two parts that can be separated from each other, the moving means formed inside the hollow portion of the polyhedron; A polyhedral fixing means positioned in the hollow portion to maintain a predetermined distance from the inner wall of the moving means, and fixed to an external movable support through a through hole formed in the moving means; And sensing means provided on an outer surface of the fixing means to detect movement of the moving means, wherein the fixing means moves the circumference of the fixing means within the predetermined interval. Force / moment sensor, characterized in that supported on. 19. The force / moment sensor of claim 18 wherein the polyhedron is a rectangular parallelepiped.