JPH05146980A - Parallel manipulator - Google Patents

Abstract

PURPOSE:To increase the calculating speed, reduce the memory capacity for calculation, and make a control board compact by controlling an intermediate member with a positioning device, and controlling a face plate with an attitude determining device. CONSTITUTION:An intermediate member 30 is rockably provided on a base 10 via a positioning device 2, a face plate 60 is rockably provided on the intermediate member 30 via a bearing, and the face plate 60 is rockably connected to the base 10 via an attitude determining device 3. The positioning device 2 determined only the position in the X, Y, Z-directions of the intermediate member 30 against the base 10, and the position and attitude of the face plate are controlled via independent calculations. The positioning device 2 is constituted of a parallelogram link or cylinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel manipulator capable of independently controlling the position and orientation, among parallel manipulators having 6 degrees of freedom.

[0002]

2. Description of the Related Art In a parallel manipulator, a face plate is supported by a position / posture determination device, and the position / posture of the face plate is determined by controlling the position / posture determination device. The face plate is provided with a processing tool or a hand and used for various purposes. The position / orientation determining device is composed of at least three sets of expansion / contraction devices, and since the face plates are supported in parallel by the expansion / contraction devices, each expansion / contraction device is small. Since the telescopic device itself is small, the manipulator itself has a small self-weight and can be made compact.

Regarding the parallel manipulator having such a characteristic, there is disclosed a principle technique in US Pat. No. 3,288,421, which was filed in 1965.
The telescopic device uses a straight-moving cylinder, and a spherical bearing is used to connect the cylinder to a face plate or a base.

The basic structure of a parallel manipulator is a base, a plurality of expansion / contraction devices, and a face plate. The base and face plate have no features, but the telescopic device has its own features. U in recent years
As disclosed in S. Pat. No. 4,806,068, there is one in which a face plate is supported by three sets of bending links. Both the posture and position of the face plate are controlled simultaneously by bending and moving the link. The link is a single connection and uses a universal joint or pin bearing.

The positioning device disclosed in Japanese Patent Laid-Open No. 59-232739 is characterized by refracting a pantograph type link. Both the position and the posture of the face plate are controlled simultaneously by the refraction angle of the link.

Japanese Patent Publication No. 03-017628, Japanese Patent Publication No. 03
In Japanese Patent Publication No. 017629, a McKinpen muscle imitating a human body is used for an expansion / contraction device to connect a base plate and a face plate via an intermediate member. In this usage, the attitude of the intermediate member is first controlled in an arc shape, and then the attitude of the face plate is controlled. This is a so-called serially connected serial manipulator.

As for the telescopic device for moving the face plate as described above, the bending link, the straight-moving cylinder,
There is a muscular body that imitates the human body, and there is also a SU1,083,017A that is controlled by the pulling action of a wire. As for the joint portion for connecting the position / orientation determining device including a plurality of expansion / contraction devices to the face plate, US Pat. No. 3,215,391,
Nos. 3,288,421 and 4,651,589 disclose spherical bearings, pin bearings, universal joints and the like.

In the parallel manipulator, each of the three points of the joint portion in which the expansion device is connected to the face plate is displaced. By doing so, the position and posture of the face plate is maintained. In such a parallel manipulator, the calculation method and the calculation speed for driving the expansion / contraction device differ depending on the structure of the expansion / contraction device, the structure of the face plate, the structure of the joint connecting the expansion / contraction device to the face plate, the presence or absence of an intermediate member, and the like. The control for positioning and the control for determining the attitude are different from each other.

[0009]

The control of a normal serial manipulator has a small storage capacity, and is generally universally used according to the configuration and application of the manipulator. That is, the position of the tip of the hand is recognized from the rotation speed of the motor, or the current position of the tip of the hand is replaced with the motor rotation speed to recognize the position. Then, these two calculations are repeated to recognize the current position and posture, and the drive command is issued. However, the above-mentioned conventional parallel manipulator is supported at three points, and both the position and the posture are driven via the same telescopic device and joint. With this configuration, it is possible to calculate for one operation of a plurality of telescopic devices, select the one to be calculated next for each operation, and calculate sequentially.

However, if a calculation result that the next operation of the face plate, the expansion device, etc. is impossible, the calculation is returned to the start of the calculation and the redone calculations are sequentially performed again. That is, if both the position and the posture are mixed and controlled by the three expansion / contraction devices, the calculation speed becomes slow and the storage capacity becomes huge, so that the control panel becomes large. Therefore, practical practical use is impossible. Generally, there are the above-mentioned drawbacks in common use. It is an object of the present invention to provide a parallel manipulator which has a high calculation speed for driving a telescopic device and has a wide three-dimensional motion range of a face plate.

[0011]

An intermediate member is swingably mounted on a substrate via a positioning device, and a face plate is swingably mounted on the intermediate member via a bearing. The face plate is swung via a posture determining device. Being movably connected to the base, the positioning device determines only the position of the intermediate member in the x, y, and z directions with respect to the base, and enables the position and orientation of the face plate to be independently calculated and controlled. A face plate is provided on the intermediate member so that it can swing freely through a support and a spherical bearing, and the positioning device can be a parallel four-sided link or a cylinder, or the positioning device can be a parallel four-sided link and the bearing can be a spherical bearing. Is. If each of the positioning device and the attitude determination device is composed of three sets of expansion / contraction devices, the structure is most stable and compact.

[0012]

The present invention will be described below with reference to the drawings. Figure 1
[Fig. 3] is a schematic diagram for explaining the operation of the present invention. The parallel manipulator of the present invention (hereinafter referred to as "manipulator") 1
Is composed of a base 10, a positioning device 2, an intermediate member 30, a posture determining device 3, and a face plate 60, and both of the intermediate member 30 and the face plate 60 are connected to each other via a point 00 where a bearing 51 is provided. The column 50 is provided to keep the point 05 of the intermediate member 30 and the point 00 of the face plate 60 at a constant interval. The positioning device 2 is composed of a plurality of telescopic devices 20.
One end of 0 indirectly connects to the base 10 via the joints 01 and 02.
The other end of the expansion / contraction device 20 is indirectly connected to the intermediate member 30 via the joints 03 and 04. Further, the column 50 is further provided on the intermediate member 30, and is connected to the face plate 60 via the bearing 00.

The column 50 may be provided on the intermediate member 30 or the face plate 60. Intermediate member 30 and face plate 6
The object of the present invention is achieved if 0 is swingably connected via the point 00 portion. A bearing 51 is provided at the point 00 portion, but a spherical bearing is the best, and a structure such that a specific surface can face three-dimensionally like a universal joint may be used. The posture determining device 3 is composed of a plurality of telescopic devices 40, and the telescopic device 40 indirectly connects the base 60 via joints 06 and 07.
Connect to. The other end is indirectly connected to the face plate 60 via the joints 08 and 09. F1 is the surface of the base 10,
F2 represents the surface of the intermediate member 30, and F3 represents the surface of the face plate 60.

The positioning action of the positioning device 2 of the manipulator 1 will be described. When one of the plurality of expansion / contraction devices 20 provided as the positioning device 2 is expanded or contracted, the angles of the joints 01 and 03 of the other expansion / contraction device are changed, and the intermediate member 30 moves in the x direction or the y or z direction. Displace. That is, the point 05 on the surface F2 freely moves in the x, y, and z directions, and the position of the intermediate member 30 having the surface F2 is determined.

Next, the operation of attitude determination by the attitude determination device 3 will be described. When one of the plurality of expansion / contraction devices 40 provided as the posture determination device 3 is expanded or contracted, the angles of the joints 06 and 08 of the other expansion / contraction device are changed, and the face plate 60 is displaced in the X direction or the Y direction. .. When all of the plurality of expansion / contraction devices 40 are equally expanded or contracted simultaneously, the face plate 60 moves up or down in the Z direction. That is,
The bearing 00 on the face F3 is free to move in the X, Y, and Z directions,
The posture of the face plate 60 having the face F3 is determined. At this time, the intermediate member 30 of the positioning device 2 is displaced x1, y1, z1.
At the position of, the posture of the face plate 60 is determined at X1, Y1, and Z1 based on the position of the intermediate member 30. Then, each of the plurality of expansion / contraction devices 40 is individually operated to further displace in the α, β, and γ directions. That is, the face plate 60 moves freely in the X, Y, and Z directions, and at the same time, α, β,
Since it also rotates in the γ direction, it can take any posture.

FIG. 2 is a conceptual view of a manipulator according to an embodiment of the present invention. Specific arcs 11 and 12 on the face plate 10
, And each joint is connected to the specified position on the arc. Similarly, with respect to the intermediate member 30 and the face plate 60, each joint is connected on the specified arc.
The connection configuration will be described below. The positioning device 2 is composed of telescopic devices 21, 22, 23, and the posture determining device 3 is composed of telescopic devices 41, 42, 43. One end of the expansion / contraction device 21 is provided on the base 10 via the joint 24. One end of the expansion / contraction device 22 is provided on the base 10 via the joint 25. Telescopic device 23
One end of is attached to the base 10 through the joint portion 26. The other end of the expansion / contraction device 21 is provided on the intermediate member 30 via the joint 27. The other end of the expansion / contraction device 22 is provided on the intermediate member 30 via the joint 28. The other end of the expansion / contraction device 23 is provided on the intermediate member 30 via the joint 29.

The intermediate member 30 is provided with columns 50, which are connected to the face plate 60 via spherical bearings 51.

One end of the expansion / contraction device 41 is provided on the base 10 via a joint 44. One end of the expansion / contraction device 42 is provided on the base 10 via a joint 45. One end of the expansion / contraction device 43 is provided on the base 10 via the joint 46. The other end of the expansion / contraction device 41 is provided on the face plate 60 via the joint 47. The other end of the expansion / contraction device 42 is provided on the face plate 60 via the joint 48. The other end of the expansion / contraction device 43 is provided on the face plate 60 via the joint 49.

The expansion / contraction device may be any structure that can expand / contract the space between one end and the other end, such as a link, a cylinder,
A screw or the like can be used. The operation of the embodiment shown in FIG. 2 is equivalent to the operation of FIG. 1 described above. A predetermined position and posture are calculated, a signal indicating the amount to be moved is output, and the actuator of the telescopic device is driven. The position of each expansion device is determined by the intermediate member 30 via the joint, and the posture is determined by the face plate 60. That is, three actuators are used for position control and three actuators are used for attitude control by feedback calculation, and the position and attitude are independently controlled by the expansion and contraction of the expansion and contraction device.

FIG. 3 shows a concrete example of the expansion / contraction device 21 of the positioning device 2. The base 10 and the intermediate member 30 are connected by a three-dimensional double parallel link unit (hereinafter referred to as "parallel link") 21 which is a telescopic device. The link portion of the parallel link 21 connects one end of the link 37 to one end of the link 35 and one end of the link 39 via the shaft 36 of the motor 18. As for the connection of this portion, the main body of the motor 18 is fixed to the link 39, and the shaft 36 is fixed to the link 35. The link 37 is rotatably provided on the shaft 36. One end of the link 34 and one end of the link 38 are rotatably connected to the other end of the link 37.

On the other hand, a link 15 is rotatably provided on the base 10 via a bearing 16.

On the other hand, a link 31 is rotatably provided on the intermediate member 30 via a bearing 33.

The other end of the link 35 is rotatably connected to the link 31 via a pin 32. The other end of the link 39 is rotatably connected to the link 15 via the pin 17. Similarly, the links 34 and 38 are also rotatably connected to the link 31 and the link 15, respectively. The connection between the B portion and the C portion in FIG. 3 is almost the same.

FIG. 4 shows a cross section taken along the line AA of FIG. Link 3
1 is rotatably supported on a bearing 33. The link 35 is rotatably provided with respect to the link 31. Each of the shaft supports may be of the shaft rotation type or the shaft fixed type as long as the region can be freely rotated.

The link 37 is rotatably provided with respect to the link 35 via a shaft 36. It is preferable that the shaft 36 itself is directly connected to the motor 18, but it may be a connecting shaft whose shaft center is matched. The motor 18 is fixed to the link 39,
The rotation torque of the motor 18 is transmitted to the link 35.

The link 15 is rotatably supported on the bearing 16 so as to be rotatable. The link 39 is rotatably provided with respect to the link 15. Each of the shaft supports may be of the shaft rotation type or the shaft fixed type as long as the region can be freely rotated.

FIG. 5 shows a specific example of the expansion / contraction device 41 of the attitude determining device 3. The base 10 and the face plate 60 are connected by a three-dimensional single parallel link unit (hereinafter referred to as "single link") 41 which is a telescopic device. In the link portion of the single link 41, one end of the link 64 and one end of the link 69 are connected to the motor 65.
Is connected via a shaft 66. The motor 65 is fixed to the link 69, and the shaft 66 is fixed to the link 64.

On the other hand, the base 10 is provided with a pair of bearings 68, and a top 67 is rotatably provided. On the other hand, the face plate 60 has
A bearing 63 having a rotatable shaft 71 is provided with respect to the face plate 60, and a top 61 is rotatably provided. In this portion, rotation is possible in any direction. A universal joint may be provided.

FIG. 6 shows a DD cross section of FIG. Face plate 60
The top 61 is rotatably supported by a bearing 63 that is rotatably supported by the link 61. Each of the shaft supports may be of the shaft rotation type or the shaft fixed type as long as the region can be freely rotated. The motor 65 is fixed to the link 69, and the motor 65
Is transmitted to the link 64. The top 67 is axially supported by the bearing 68, and the link 69 is rotatably provided with respect to the top 67.

Next, the operation will be described with reference to FIG. When the rotation torque of the motor 65 is transmitted to the link 64, the link 64 starts to rotate, the angle formed by the link 69 and the link 64 changes, and the face plate 60 also rotates.

On the other hand, the parallel link 21 and the single link 41 capable of performing the above-described actions are provided with three sets as the positioning device and three sets as the attitude determining device shown in FIG. Since the joint part can be moved three-dimensionally in this way, when the three sets of parallel links 21 for positioning are freely actuated, the intermediate member 30 is displaced in x, y, z, and the three sets for posture determination are set. When the single link 41 of X operates freely, the face plate 60 becomes X, Y, Z
Displacement of. Further, the α, β, and γ axis displacements can be further performed with respect to the X, Y, and Z displacements. The position is determined by the intermediate member 30, and the posture is determined by the face plate 60.

[0015]

According to the present invention, since the positioning device controls the intermediate member and the posture determining device controls the face plate independently, the calculation speed is increased. In addition, the control panel is compact because the storage capacity for calculation is small. Therefore, it can be practically used practically and can be widely used in general.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating the operation of the present invention.

FIG. 2 is a three-dimensional conceptual diagram of a manipulator according to an embodiment of the present invention.

FIG. 3 is a specific example of the expansion device 21 shown in FIG.

4 is a cross section taken along the line AA of FIG.

5 is a specific example of the expansion device 41 shown in FIG.

6 is a cross section taken along line DD of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Manipulator 2 Positioning device 3 Posture determination device 10 Base 20 Expansion / contraction device 30 Intermediate member 40 Expansion / contraction device 50 Strut 51 Bearing 60 Face plate

Claims (5)

[Claims] 1. A base member is provided with a swingable intermediate member via a positioning device, a swingable face plate is provided on the intermediate member via a bearing, and the face plate is swingable with a posture determining device. The parallel manipulator is characterized in that the positioning device determines only the position of the intermediate member in the x, y, and z directions with respect to the base, and the position and orientation of the face plate can be controlled by independent calculations. .. 2. The parallel manipulator according to claim 1, wherein the intermediate member is provided with a face plate swingably via a support and a spherical bearing. 3. The parallel manipulator according to claim 1, wherein the positioning device is a parallelogram link or a cylinder. 4. The positioning device is a parallelogram link,
The parallel manipulator according to claim 1, wherein the bearing is a spherical bearing. 5. The positioning device and the attitude determining device each have three units.
A parallel manipulator according to claim 1, comprising a set of telescopic devices.