JPH10180673A - Positioning device and positioning method with three-dimensional space latitude - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size and cost of a positioning device with three- dimensional space latitude for positioning a work in a predetermined position in space. SOLUTION: A positioning device 1 with three-dimensional space latitude comprises a base 2, three telescopic rods 10, a telescopic direct-acting actuator 20 having at its tip a positioning sphere 29, and a linear position sensor 16 for finding the position of the positioning sphere 29 of the actuator 20. The three rods 10 are arranged on the base 2 like a tripod with the actuator 20 being situated at the substantial center. The actuator 20 and the rods 10 are jointed at their base ends on the base 2 by means of universal joints, and are coupled together at their positioning-sphere side and tips allowing for the motions of their spherical surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-degree-of-freedom positioning apparatus and method for positioning a work at a predetermined position in a space.

[0002]

Conventionally, as a device having three degrees of freedom as described above, there is a device having three independent linear motion actuators. In this device, three linear motion actuators are used. In addition to the actuator, a linear motion actuator requires an individual operation amount control mechanism, which makes the device large and expensive, making it difficult to lay out as a positioning device and reducing equipment costs. There is a problem that it is not possible to solve these problems, and it has been a conventional problem to solve these problems.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is a space 3 capable of positioning a work at a predetermined position in the space while realizing compactness and low cost. It is an object of the present invention to provide a positioning device and a positioning method with a degree of freedom.

[0004]

According to a first aspect of the present invention, there is provided a positioning device having three degrees of freedom in a space, comprising a base, three extensible rod members, a rod-shaped member, and a work contact portion at a tip end. Telescopic drive means for extending and contracting, and position detecting means for detecting the position of the work contact portion in the telescopic drive means, wherein the three rod members are tripod-shaped on the base with the telescopic drive means substantially at the center. And the base ends of the telescopic drive means and the rod member are connected to the base in a spherical pair, respectively, and the work contact side of the telescopic drive means and the distal ends of the three rod members are connected to each other. Are connected to form a spherical pair, and the configuration of the positioning device having three degrees of freedom in space is a means for solving the conventional problems.

A positioning device having three degrees of freedom in a space according to a second aspect of the present invention is configured such that a rod member is constituted by a telescopic rod having a cylindrical case and a movable shaft slidably fitted to the cylindrical case. Space 3 according to claim 3 of the present invention
The positioning device having a degree of freedom has a configuration in which the expansion / contraction driving means is a linear motion actuator, and the positioning device having three degrees of freedom in the space according to claim 4 of the present invention has a position detection means provided on each of three rod members. It is configured as a quantity detector.

In the positioning device having three degrees of freedom in the space according to the fifth aspect of the present invention, a brake for restricting expansion and contraction provided on the rod member and an expansion and contraction amount detector provided respectively corresponding to the three rod members are provided. A positioning feedback circuit that controls the expansion and contraction operation of the expansion and contraction driving unit based on the amount of expansion and contraction of the rod member that is fed back, and a changeover switch that selects one positioning feedback circuit from the three positioning feedback circuits and connects to the expansion and contraction driving unit Configuration.

[0007] The positioning device with three degrees of freedom of the space according to claim 6 of the present invention has a configuration in which the workpiece contact portion is spherical, and the positioning device of space with three degrees of freedom according to claim 7 of the present invention. The work contact part also serves as a work holding part.

[0008] In the positioning method of three spatial degrees of freedom according to claim 8 of the present invention, when positioning a workpiece by the positioning device of three spatial degrees of freedom according to any one of claims 1 to 7, three rods are used. While maintaining the length of the two rod members of the members, the expansion and contraction driving means is operated to expand and contract to expand and contract only the remaining one rod member,
Next, based on the position of the work contact portion detected by the position detecting means, the two rod members that maintain the length and the one rod member that expands and contracts following the expansion and contraction operation of the expansion and contraction driving unit are sequentially changed. While moving the work abutting part to a predetermined part by repeatedly performing the expansion and contraction operation of the expansion and contraction driving means,
The configuration is such that the positioning point of the workpiece is brought into contact with the workpiece abutting portion located at the predetermined portion, and the configuration of the positioning method having three degrees of freedom is a means for solving the conventional problem.

[0009]

According to the positioning apparatus with three degrees of freedom of the space according to the first to third aspects of the present invention, the three rod members (the space according to the second aspect) are used when positioning the work. In the three-degree-of-freedom positioning device, the length of two rod members of the telescopic rod is maintained, and the telescopic drive means (in the three-degree-of-freedom positioning device according to claim 3, a linear motion actuator). When only the remaining one rod member is expanded and contracted to expand and contract, the expansion and contraction driving means connected to the base in a spherical pair with the base rotates about the base end, so that the workpiece abuts. The part moves in the direction in which the rod member allowed to expand and contract extends or contracts.

Next, based on the position of the workpiece contact portion detected by the position detecting means, two rod members for maintaining the length and one rod member for allowing the expansion and contraction are sequentially changed, and the expansion and contraction driving means is changed. Is repeated, the work contact part moves to the predetermined part, and if the work positioning point is brought into contact with the work contact part located at the predetermined part, the work is positioned at the predetermined position in the space. Will be done.

That is, since only one expansion / contraction drive means is required for obtaining three degrees of freedom in the space, the size and cost of the apparatus can be reduced.

According to the positioning device of the present invention, if the expansion and contraction amount detectors provided on the three rod members detect the respective expansion and contraction amounts of the rod members, the work abutting portion can be detected. The position is uniquely determined, that is, the position of the work contact portion is detected with a simple structure. Space 3
In spite of the fact that there is only one expansion / contraction drive means for obtaining the degree of freedom, the work can be positioned at a predetermined position in the space by a simple operation.

[0013] In the positioning device having three degrees of freedom in the space according to the sixth aspect of the present invention, since the above-described configuration is employed, regardless of the difference in the posture of the expansion and contraction driving means in the state where the work contact portion has moved to the predetermined portion. When the workpiece abutment portion and the positioning point of the workpiece are in point contact with each other, the workpiece is positioned at a predetermined position in the space. At this time, when the positioning point of the workpiece is a positioning hole, a spherical workpiece is formed. If the diameter of the contact part matches the diameter of the positioning hole,
Regardless of the difference in the posture of the expansion / contraction drive means, the work contact portion and the work positioning hole are fitted to each other, so that the work is positioned at a predetermined position in the space, and the space according to claim 7 of the present invention. In a 3-DOF positioning device,
The work is grasped simultaneously with the positioning of the work at a predetermined position in the space.

According to the positioning method for three degrees of freedom of the space according to the eighth aspect of the present invention, since the above-described configuration is used, only one expansion / contraction driving means for obtaining three degrees of freedom of the space is used, and the positioning method at a predetermined position in the space is achieved. The work is positioned.

[0015]

According to the positioning apparatus having three degrees of freedom of the space according to the first to third aspects of the present invention, the expansion / contraction drive means for obtaining three degrees of freedom of the space can be provided as one piece because of the above-mentioned configuration. Therefore, a very excellent effect that the size and cost of the device can be reduced is provided.

In the positioning apparatus having three degrees of freedom in the space according to the fourth aspect of the present invention, since the above-described configuration is employed, the position of the workpiece contact portion can be detected with a simple structure. In the positioning device with three degrees of freedom relating to the above, the above-described configuration makes it possible to operate the work piece at a predetermined position in the space with a simple operation despite the fact that only one expansion / contraction drive means for obtaining three degrees of freedom in space is provided. This is a very excellent effect that the positioning can be performed.

[0017] In the positioning device having three degrees of freedom of the space according to claim 6 of the present invention, the above-described configuration allows the positioning device to extend and retract regardless of the difference in the posture of the expansion / contraction drive means when the workpiece abutment portion moves to a predetermined portion. The work can be positioned at a predetermined position in the space, and the positioning device having three degrees of freedom in the space according to the seventh aspect of the present invention can simultaneously grip the work at the predetermined position in the space. This is a very good effect.

According to the positioning method of three degrees of freedom of the space according to the eighth aspect of the present invention, since the above-mentioned configuration is used, only one expansion / contraction driving means for obtaining three degrees of freedom of the space is used, and the predetermined position in the space can be obtained. A very excellent effect that the work can be positioned can be obtained.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIGS. 1 to 6 show an embodiment of a positioning device having three degrees of freedom according to the present invention. As shown in FIG. 1, this positioning device 1 having three degrees of freedom has a substantially equilateral triangle. Two bases, three telescopic rods (rod members) 10 and a linear motion actuator (telescopic drive means) 2
0 is provided.

As shown in FIG. 2, the telescopic rod 10 includes a cylindrical case 11 having a bottom, and a movable shaft 12 slidably fitted to the cylindrical case 11. At the lower end of the protruding fixed shaft portion 13 (the base end of the rod member) and at the upper end of the movable shaft portion 12 (the distal end of the rod member), spheres 14 and 15 are provided, respectively. A linear position detector (extension / contraction detector; position detecting means) 16 for detecting the amount of movement of the movable shaft 12 and a brake 17 for gripping and releasing the movable shaft 12 are provided.

As shown in FIG. 3, a linear motion actuator 20 as a telescopic drive means includes a servo motor 21, a cylindrical case 22 fixed to the upper end of the servo motor 21,
A ball screw shaft 23 having a lower end supported by a bearing 22a located inside the cylindrical case 22 connected to an upper end of an output shaft 21a of the servo motor 21 via a coupling 22b, and slides on the cylindrical case 22. Hollow portion 24a which is fitted so as to be able to be inserted into and removed from the ball screw shaft 23.
, A ball screw nut 25 provided at the opening of the hollow portion 24 a of the movable shaft portion 24 to form a screw pair with the ball screw shaft 23, and a movable shaft portion provided at the upper end opening of the cylindrical case 22. And a guide 26 for restricting the rotation of the servomotor 21.
8 is provided, and a positioning sphere (work contact portion) 29 is provided on the upper end of the movable shaft portion 24 (the end of the telescopic drive means).
Is provided.

The three telescopic rods 10 are arranged in a tripod shape with the spheres 14 at the lower ends thereof positioned at three corners of the base 2, respectively.
Are disposed so as to be located substantially at the center of three telescopic rods 10 assembled in a tripod shape.
0 and the sphere 1 at the lower end of each of the linear actuators 20
4 and 28 are respectively fitted in the spherical grooves 3 a of the cylindrical body 3 provided on the base 2, and the spheres 15 at each upper end of the telescopic rod 10 are located near the upper end of the movable shaft portion 24 in the linear motion actuator 20. Each spherical groove 4 of the provided three-pronged socket 4
a.

The positioning device 1 having three degrees of freedom in this space
As shown in FIG. 4, each of the telescopic rods 10 is provided with a positioning feedback circuit 5 electrically connected to the linear position detector 16 and the brake 17 of the telescopic rod 10, and the linear motion actuator 20 is telescopically operated. Each time it is performed, three positioning feedback circuits 5 (5A, 5A)
B, 5C) is provided with a changeover switch 6 for selecting and functioning one of the positioning feedback circuits 5 from among the positioning feedback circuits 5 selected by the changeover switch 6, for example, the positioning feedback circuit 5A.
The movable shaft portion 12A is released from the restraint by the brake 17A corresponding thereto, and the movement amount of the movable shaft portion 12A of the telescopic rod 10A operating following the expansion and contraction operation of the linear motion actuator 20 is thereby detected by the linear position detector 16A. , And functions to stop the expansion / contraction operation of the linear motion actuator 20 based on the amount of movement of the movable shaft portion 12A which is detected and fed back.

Reference numeral 7 in FIG. 4 denotes a servo amplifier.

When positioning the workpiece by the positioning device 1 having three degrees of freedom, the telescopic rod 10
In the initial state where the lengths of (10A, 10B, 10C) are the same (the state shown by the solid line in FIG. 5A), first,
When, for example, the positioning feedback circuit 5A is selected from the three positioning feedback circuits 5A, 5B, 5C by the changeover switch 6, the brake 17A of the telescopic rod 10A corresponding to the selection is released, and the movable shaft portion 12 is released.
A is slidable (the telescopic rod 10A is telescopic),
The other two telescopic rods 10B and 10C maintain the initial length.

When the linear motion actuator 20 is extended in this state, as shown in FIG. 5 (b), the linear motion actuator 20 itself expands around a spherical body 28 connected to the base 2 in a spherical pair. And the selected telescopic rod 10A expands following the extension operation of the linear motion actuator 20 and tilts more to the left while extending.
And the direction in which the selected telescopic rod 10A has fallen (FIG. 5).
(B) to the left).

During this time, the positioning feedback circuit 5A
, The moving amount of the movable shaft 12A is fed back from the linear position detector 16A of the telescopic rod 10A,
When the moving amount of the movable shaft portion 12A reaches a predetermined value, the linear motion actuator 20 stops its extension operation.

Next, it is uniquely determined from the moving amount of the movable shaft portion 12A detected by the linear position detector 16A of the telescopic rod 10A and the initial length maintained by the other two telescopic rods 10B and 10C. When, for example, the positioning feedback circuit 5B is selected from the two positioning feedback circuits 5B and 5C other than the positioning feedback circuit 5A by the changeover switch 6 based on the position of the positioning sphere 29, the telescopic rod 10B corresponding thereto is selected.
The movable shaft portion 12B is slidable (the telescopic rod 10B is telescopic), the telescopic rod 10A maintains the above-described extended length, and the telescopic rod 10C maintains the initial length.

When the linear actuator 20 is further extended in this state, as shown in FIG. 5C, the linear actuator 20 itself rotates while extending,
Since the selected telescopic rod 10B extends right following the extension operation of the linear motion actuator 20 and tilts rightward, the positioning sphere 29 moves in the direction in which the linear motion actuator 20 and the selected telescopic rod 10B fall (FIG. 5 ( c) to the right), and the linear position detector 16B of the telescopic rod 10B sends the positioning feedback circuit 5B.
When the moving amount of the movable shaft portion 12B fed back to the above reaches a predetermined value, the linear motion actuator 20 stops its extension operation.

Thereafter, the positioning feedback circuits 5A, 5B and 5C are sequentially selected by the changeover switch 6, that is, one telescopic rod 10 (10A, 10
B, 10C) are sequentially changed, and the linear motion actuator 20 is repeatedly operated to extend, as shown by a virtual line in FIG. 5A, the positioning sphere 29 moves to a predetermined portion, and the positioning sphere 29 moves to the predetermined portion. When the positioning point S of the panel (work) P is brought into contact with the positioned positioning sphere 29 as shown in FIG. 6A, the positioning of the panel P at a predetermined position in the space is achieved. Become.

At this time, if the positioning point of the panel P is the positioning hole H as shown in FIG. 6B, the diameter d of the positioning sphere 29 should be adjusted to the diameter D of the positioning hole H. Then, the positioning sphere 29 and the positioning hole H are fitted, and the panel P is positioned at a predetermined position in the space. Further, as shown in FIG. 6C, if the gripping sphere 30 is provided so as to face the positioning sphere 29 with the positioning point S of the panel P interposed therebetween, the panel P can be gripped simultaneously with the positioning of the panel P. Will be done.

Therefore, in the positioning device 1 having three degrees of freedom in the space described above, despite the fact that there is only one linear actuator 20 for obtaining three degrees of freedom in the space, the panel at a predetermined position in the space can be easily operated. The position of P is determined, and the size and cost of the apparatus can be reduced by the amount of the single linear actuator 20.

In the positioning device 1 having three degrees of freedom in the above-mentioned space, if the moving amount of each movable shaft portion 12 is detected by the linear position detectors 16 provided on the three telescopic rods 10, respectively, the positioning sphere 29 Is determined uniquely, that is, the positioning sphere 29 is formed with a simple structure.
Will be detected.

Further, in the positioning device 1 having three degrees of freedom in the space, since the workpiece abutment portion is a positioning sphere 29, when the positioning sphere 29 is moved to a predetermined portion, the dashed line in FIG. As indicated by the two-dot chain line, even if the linear motion actuator 20 is greatly inclined within the restricted range (in this embodiment, within the range of the maximum inclination angle of about 30 ° with respect to the axis perpendicular to the base 2),
Since the positioning sphere 29 and the positioning point S of the panel P are in point contact with each other, the positioning of the panel P at a predetermined position in the space is ensured.

The detailed configuration of the positioning device and the positioning method with three degrees of freedom according to the present invention is not limited to the above-described embodiment.

[Brief description of the drawings]

FIG. 1 is an overall perspective explanatory view showing one embodiment of a positioning device having three degrees of freedom in a space according to the present invention.

FIG. 2 is an explanatory sectional view showing a telescopic rod (rod member) of the positioning device in FIG.

FIG. 3 is an explanatory sectional view showing a linear motion actuator (expansion / contraction drive means) of the positioning device in FIG. 1;

FIG. 4 is a diagram illustrating a control system of the positioning device in FIG.

5 (a), (b) and (c) are explanatory views of the operation of the positioning device shown in FIG.

FIG. 6 is a partially enlarged explanatory view (a) of a state in which a positioning sphere (work contact portion) of the positioning device in FIG. 1 is in contact with a positioning point of a panel (work), and a positioning sphere and a positioning hole of the panel; (B) and (c) a partially enlarged explanatory view of a state where the positioning sphere is gripping the panel simultaneously with the positioning of the panel.
It is.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Positioning device of three degrees of freedom of space 2 Base 5 Positioning feedback circuit 6 Changeover switch 10 Telescopic rod (rod member) 11 Cylindrical case 12 Movable shaft part 16 Linear position detector (expansion and contraction amount detector; position detecting means) 17 Brake 20 Straight Dynamic actuator (telescopic drive means) 29 Sphere for positioning (work contact part) P panel (work)

Claims (8)

[Claims] 1. A base, three extensible rod members, a telescopic drive means having a rod-like shape and having a work contact part at a tip thereof, and a telescopic drive means, and a position of the work contact part in the telescopic drive means. And three rod members are disposed on the base in a tripod shape with the telescopic drive unit substantially at the center, and the base ends of the telescopic drive unit and the rod member are positioned with respect to the base. A three-degree-of-freedom positioning apparatus, wherein a spherical pair is connected to each other, and a work contact portion of the expansion / contraction drive means and each tip of the three rod members are connected to each other in a spherical pair. . 2. The positioning device according to claim 1, wherein the rod member is a telescopic rod having a cylindrical case and a movable shaft slidably fitted to the cylindrical case. 3. The positioning device according to claim 1, wherein the expansion / contraction drive means is a linear motion actuator. 4. The positioning device according to claim 1, wherein the position detecting means is an expansion / contraction detector provided on each of the three rod members. 5. An expansion / contraction driving means based on the expansion / contraction control brake provided on the rod member and the expansion / contraction amount of the rod member provided corresponding to each of the three rod members and fed back from the expansion / contraction detector. 5. A positioning device having three degrees of freedom in space according to claim 4, further comprising: a positioning feedback circuit for controlling the expansion / contraction operation, and a changeover switch for selecting one positioning feedback circuit from the three positioning feedback circuits and connecting to the expansion / contraction driving means. . 6. The positioning device according to claim 1, wherein the workpiece contact portion is spherical. 7. The positioning device according to claim 1, wherein the work contact portion also serves as a work holding portion. 8. When positioning a workpiece by the positioning device having three degrees of freedom in space according to any one of claims 1 to 7, the length of two of the three rod members is maintained. In this state, the telescopic drive means is operated to expand and contract, and only the remaining one rod member is expanded and contracted.
Based on the position of the work contact portion detected by the position detecting means, the two rod members that maintain the length and the one rod member that expands and contracts following the expansion and contraction operation of the expansion and contraction driving unit are sequentially changed. Wherein the expansion / contraction drive means is repeatedly extended and retracted to move the workpiece contact portion to a predetermined portion, and to cause the workpiece positioning portion to come into contact with the workpiece contact portion located at the predetermined portion. Positioning method.