JPH06143165A - Robot for work - Google Patents

Abstract

PURPOSE:To prevent collision of a manipulator and a working unit with other obstacle than a working surface by limiting the operation region of a manipulator. CONSTITUTION:A working unit 4 making contact with a working surface to perform a work is arranged to the tip of a manipulator 1. The manipulator 1 comprises first and second arms 2 and 3; a drive part R2 for a first arm; and a passive rotation part R3. The passive rotation part R3 is arranged to the tip of the first arm 2 and a driven pulley 6 which a drive part R2 for a first arm comprises is coupled to a fixed pulley 5 on the fixed side through a belt 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working robot having a working unit attached to the tip of a manipulator,
In particular, the present invention relates to a work robot capable of safely performing cleaning, cleaning, polishing work, etc. by a work unit attached to the tip of a manipulator.

[0002]

2. Description of the Related Art There is generally known a working robot in which a working unit such as a polishing unit or a cleaning unit is attached to the tip of a manipulator and the working unit is pressed against a work surface. When performing work using such a work robot, 5 to 6
A manipulator having a degree of freedom is used.

FIG. 15 shows a conventional work robot for cleaning a windshield of a jumbo jet machine by attaching a cleaning unit to the tip of a manipulator having five degrees of freedom. In FIG. 15, R _{1 to} R ₅ indicate joints of the manipulator. That is, in FIG. 15, the manipulator 100 is attached to the hatch 101 of the jet aircraft 110 via the attachment portion 102, and the cleaning unit 106 for cleaning the windshield 105 is provided at the tip of the manipulator 100. Manipulator 100
Has a plurality of arms 103 and 104 and a plurality of arm drive units (joints) R _{1 to} R ₅ .

On the other hand, for the purpose of light weight and low cost,
There has been proposed a work robot having a 2- to 4-axis manipulator and a mechanism that passively follows the work surface and performing the same work (Japanese Patent Application No. 3-123951).

[0005]

When performing work such as cleaning work using the work robot as described above, it is necessary to ensure that the arm and work unit do not collide with the work surface or human due to runaway of the manipulator. Need to take safety measures. In particular, in a work robot that cleans the windshield of a jumbo jet aircraft, it is necessary to prevent damage to the machine body or the like for safe operation.

Usually, the operating range of the arm is set for the purpose of safety measures, but in this case, the operating range is set by a soft, electrical or mechanical method. Of these, the soft or electric hardware operation restriction may cause runaway or malfunction, but the method of mechanically limiting the operation, that is, the method with a mechanical stopper, is the most reliable because there is no fear of runaway or malfunction. It is highly likely.

In the case of a conventional work robot as shown in FIG. 15, the drive units R ₁ and R ₂ (first and second axes) are operated by mechanical stoppers within a range that does not damage the machine body. Setting limits is easy.
However, regarding the drive unit R ₃ (third axis), in consideration of storage, carrying, setting, etc., an operation area of about 180 degrees from the folded state to the unfolding is required,
The second axis R ₂ of the posture, it is conceivable that interfering with the aircraft.

The present invention has been made in consideration of the above points, and an object of the present invention is to provide a safe work robot in which the manipulator does not mechanically interfere with a work surface such as a machine body.

[0009]

According to the present invention, there is provided a working robot having a working unit for contacting a working surface at a tip of a manipulator to carry out a work, wherein the manipulator is at least a first arm and a second arm connected to each other. The arm includes an arm, a first arm drive unit provided at a base end of the first arm for rotationally driving the first arm, and a passive rotation unit provided at a tip end of the first arm. The part is connected to a fixed side of the first arm drive part through a connecting mechanism, and rotates with the rotational movement of the first arm to rotationally drive the second arm. .

[0010]

According to the present invention, as the first arm driving unit rotates and moves the first arm, the passive rotating unit provided at the first arm moving end has the fixed side of the first arm driving unit and the connecting mechanism. And the second arm is rotationally driven by this passive rotating part.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 are views showing a first embodiment of a work robot according to the present invention. Of these, FIG. 1 is a front view of the work robot, and FIG. 2 is a perspective view thereof.

1 and 2, the work robot includes a manipulator 1 having a first arm 2 and a second arm 3, and a work unit 4 provided at the tip of the manipulator 1. Further, the manipulator 1 includes a turning drive unit R ₁ which is a turning shaft, a first arm drive unit R ₂ which is provided at a base end of the first arm 2 and rotationally drives the first arm _2, and a tip end of the first arm ( 'and the passive rotary part R _3' passive rotary part R ₃ which rotates with the rotation of the first arm 2 is provided to the mobile terminal) the second arm driving unit for rotationally driving the second arm 3 is rotated relative to R ₃ and.

As shown in FIGS. 1 and 2, the turning drive unit R
₁ , the first arm driving unit R ₂ and the second arm driving unit R ₃ are driven by the servomotors 11, 12, 13 and the speed reducers 21, 22, 23, respectively.

A working unit 4 rotatably supported around two axes is attached to the tip of the second arm 3. The configuration of the distal end portion of the second arm 3 may be any suitable one according to the work, but a further rotation drive unit may be provided as necessary.

The operation mechanism of the passive rotating part R ₃ ′ is as follows. A fixed pulley 5 is fixed to the fixed side of the first arm drive unit R ₂ provided on the output shaft of the turning drive unit R ₁ coaxially with the drive shaft. On the other hand, a driven pulley 6 rotatably supported by the first arm 2 is arranged at the tip (moving end) of the first arm 2, and the driven pulley 6 constitutes a passive rotating portion R ₃ ′. ing. The fixed pulley 5 and the driven pulley 6 are both toothed pulleys, and the toothed belt 7 is applied to both pulleys 5 and 6 with appropriate tension without slack. The connecting mechanism between the first arm driving unit R ₂ and the passive rotating unit R ₃ ′ is not limited to the toothed belt and the pulley, and a method of fixing the steel belt to the flat pulley does not cause rattling or stretching. Any method may be adopted as long as it is small.

Next, the operation state of the arms 2 and 3 will be described when the tooth ratio of the fixed pulley 5 and the driven pulley 6 is 2: 1. For example, a case where the arms 2 and 3 are expanded from the folded state to the horizontal state will be described. As shown in FIG. 3, the first arm driving unit R ₂ drives the first arm 2
When 90 ° is rotated from the vertically upward state to the horizontal state, the rotation angle of the second arm 3 rotated by the passive rotation unit R ₃ ′ with respect to the first arm 2 is twice the rotation angle of the first arm 2, that is, It will be 180 degrees. Therefore, even if the second arm driving unit R ₃ is not driven at all, the passive rotating unit R ₃ ′ is
Only then, the second arm 3 can be deployed to a horizontal state.

On the other hand, as shown in FIG. 4, in the manipulator 1 having the conventional joint structure, the first and second arms 2,
To unfold 3 from the folded state to the horizontal state,
It is necessary to prepare the operation range of the second arm 3 by 180 degrees. That is, when the first arm 2 and the second arm 3 have the same length, the operating range of the manipulator 1 is as shown by the chain double-dashed line in FIG. In addition, the interference region of the first and second arms 2 and 3 is the two-dot chain line outline range of FIG.
When working on a limited area of the manipulator 1, there is a risk of collision, destruction, etc. Therefore, the first and second arms 2 and 3 are mechanically operated so as to operate only within the working area. It is desirable to limit it. However, the conventional method may operate over a wide range other than the work area, as shown in FIG.

On the other hand, in the work robot according to the present invention, the first arm 2 and the second arm 3 have the same length, and the tooth ratio (pulley ratio) between the fixed pulley 5 and the driven pulley 6 is 2: If the operating range of the first and second arm drive units R ₃ is 30 degrees, the operating range of the manipulator 1 can be limited to the chain double-dashed line shown in FIG. Further, as shown in FIG. 5, the interference region of the first and second arms 2 and 3 is narrow, and even if there is an obstacle above, there is no risk of interference and it is safe.

In the above embodiment, an example of the arm length, the pulley ratio, the operating range of the drive shaft, etc. has been described. However, by appropriately selecting these, the working area can be mechanically applied to other working areas. Can be limited.

For example, the first arm 2 and the second arm 3
When the lengths of the first and _second driven parts are the same, the ratio between the fixed pulley 5 and the driven pulley 6 is 1.6: 1, and the operating range of the first arm driving part R ₂ is 100 degrees, the second arm driving part The locus of the second arm 3 when R ₃ is not driven is as shown by the solid line in FIG. In the case of cleaning the windshield of a jumbo jet machine, it is desired that the manipulator 1 does not interfere with the first and second arms 2 and 3 and the machine body. Therefore, in FIG. 6, the operating region (2) of the manipulator 1 when the operating range of the second arm driving unit R ₃ is 20 degrees.
Compared with the dotted line) and the approximate shape of the nose portion 110 of the jumbo jet (dotted line), the first and second arms 2 and 3 do not substantially interfere mechanically with the nose portion 110, and the tip of the manipulator 1 The part can reach the windshield 105.

Conventionally, the operating range of the second arm driving section R ₃ is required to be 180 degrees, and the interference area with the airframe is wide. However, according to the present invention, the second arm driving section R ₃ operates. The range is only 20 degrees, and the interference with the airframe can be eliminated.

Since the shape of the machine body and the fixed position of the manipulator base with respect to the machine body may change, the arm length ratio, pulley ratio, and operating range described in the above embodiments are not necessarily optimum. Absent. These may be appropriately selected depending on the case.

Next, a state in which a balance mechanism is added to the manipulator by a spring or the like will be described with reference to FIG. In FIG. 7A, one end 32 of the spring 31 is fixed to the belt 7, and the other end 33 is fixed to the first arm 2. In the stored state (vertical state), the spring 31 is in a natural length state. From this state, the first arm drive unit R ₂
As the first arm 2 is driven in the horizontal direction and the first arm 2 is tilted in the horizontal direction, the relative positions of the fixed positions 32 and 33 of the spring 31 move in the direction of moving away from each other, so that a force to contract the spring 31 acts. By balancing this contracting force and the weights of the first arm 2 and the second arm 3, the first arm drive unit R ₂
The self-weight compensation of Therefore, it is possible to reduce the output torque of the first arm driving unit R ₂ that requires a large output torque, and thus the first arm driving unit R ₂ can be reduced.
_2, the weight can be reduced.

Similarly, as shown in FIG. 7B, the spring 31
The one end portion 32 may be fixed to the first arm 2 and the other end portion 33 may be fixed to the fixed side of the first arm driving unit R ₂ . Alternatively, a weight may be provided on the rear side of the base end side of the second arm 3 to compensate for the own weight of the second arm driving unit R ₃ with respect to the second arm 3.

The self-weight compensation (self-weight balance) mechanism shown in FIGS. 7A and 7B can be applied to each embodiment described later.

Next, the second working robot according to the present invention will be described.
An embodiment of the above will be described with reference to FIGS. In the first embodiment, the pulley and the belt are used as the connecting mechanism between the first arm driving unit R ₂ and the passive rotating unit R ₃ ′, but in the present embodiment, a link mechanism is further used. The same operation is realized.

FIG. 8 is a perspective view showing a second embodiment of the work robot. In FIG. 8, the same parts as those in the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 8, a fixed pulley 5 is provided on the fixed side of the first arm driving section R ₂ . The fixed pulley 5 is connected to a driven pulley 13 via a belt 7, and the driven pulley 13 is mounted on the first arm 2 to form a bearing 1.
It is rotatably held by 2. Also, the first arm 2
The mobile terminal passive rotary part R ₃ 'is provided, the passive rotary part R _3' and the driven pulley 13 is connected by a parallel link mechanism 11 comprised of the link 8, 9, 10 and the second arm 2 ing.

FIG. 9 is a diagram showing the movement of the link and the arm in this embodiment. Vertical state (First arm 2
Indicates the movement from the upper side, the second arm 3 downward) to the horizontal state by driving the first arm driving unit R ₂ . The link 8 moves along with the movement of the first arm 2 and the belt 7
And is driven passively by the fixed pulley 5 and the driven pulley 6. The movement of the link 8 is transmitted to the link 10 by the parallel link mechanism 11. In FIG. 9, in order to facilitate the explanation, the pulley ratio of the fixed pulley 5 and the driven pulley 6 is 2: 1, the first arm driving unit R ₂ is driven 90 degrees, and the passive rotating unit R ₃ ′ is 180 degrees. It shows the case of being driven.

According to the present embodiment, by using the parallel link mechanism 11, the rigidity of the joint portion such as the first arm driving portion R ₂ or the passive rotating portion R ₃ ′ due to the stretching of the belt is reduced. It can be prevented.

Next, a modification of the second embodiment will be described with reference to FIG. In FIG. 8, the pulleys 5 and 13, the belt 7 and the parallel link mechanism 11 are used, but in this modification, the pulley and the belt portion are replaced with a gear mechanism 40 having a planetary gear 42.

In FIG. 10, the carrier 44 of the planetary gear 42 is fixed to the output shaft side of the turning drive unit R ₁ (the fixed side of the first arm drive unit R ₂ ). The drive shaft of the first arm drive unit R ₂ rotates with respect to the carrier 44, and the first arm 2 is fixed to the drive shaft. The drive shaft of the first arm drive unit R ₂ is input to the sun gear 43. In this case, the output from the sun gear 43 is the planetary gear 42.
It is transmitted to the internal gear 41 via the, and the link 8 is fixed to the internal gear 41.

With respect to the rotation of the sun gear 43, the internal gear 41
Rotate in the opposite direction, and the ratio can easily be set to about 1: 2. Therefore, it is possible to perform a function similar to that of the pulley and belt transmission mechanism as described above. Figure 1
The parallel link mechanism 11 shown in FIG. 0 is the same as that shown in FIG.

By using the gear mechanism 40 as in this embodiment, the rigidity of the joint can be further increased,
In addition, the joint portion can be downsized.

FIG. 11 is an explanatory view when a balance mechanism such as a spring is added to the manipulator 1 in FIG. In FIG. 11, one end 32 of the spring 31 has the link 1
At the intersection of 0 and the first arm 2, the other end 33 of the spring 31 is fixed at the intersection of the link 9 and the link 8. In the stored state (vertical state), the spring 31 is in a natural length state. From that state, as the first arm driving unit R ₂ is driven and the first arm 2 is tilted in the horizontal direction, the fixing position 3 of the spring 31 is increased.
Since the relative positions of 2, 33 move away from each other, the force of contracting the spring 31 acts, and the torque of the first arm driving unit R ₂ can be reduced.

Next, a third embodiment of the work robot according to the present invention will be described.
The embodiment will be described with reference to FIG. In this embodiment, FIG.
As shown in FIG. 2, the passive rotating part R ₃ ′ is driven only by the link mechanism. A link 51 is fixed to the output shaft side of the turning drive unit R ₁ (the fixed side of the first arm drive unit R ₂ ). Further, the first arm ₂ is driven by the driving of the first arm driving unit R ₂ . The links 52 and 53 having different lengths are rotatably connected to the link 51. Further, the second arm 2 is adapted to rotate with respect to the passive shaft R ₃ ′ by the second arm driving unit R ₃ .

FIG. 13 is a view showing the functions of the link and the arm in the present embodiment. From the vertical state (the first arm 2 is upward and the second arm 3 is downward), the first arm drive section is shown. It shows the movement until driving R ₂ to the horizontal state. Since the link mechanism including the first arm 2 and the links 51, 52, and 53 is not a parallel link mechanism, the angle of the link 53 changes according to the angle of the first arm driving unit R ₂ , and the passive rotating unit R ₃ ′ changes. Driven. In FIG. 13, the ratio of the lengths of the first arm 2 and the links 51, 52, 53 is 30: 12: 37: 5.

This length ratio is (first arm length + link 53 length) ² + link 51 length ² = in the vertical state.
Link 52 length ^{2 In} horizontal state, 1st arm length + link 51 length = link 53 length + link 5
We are satisfied with the second chief. The link ratio is not limited to this, and may be set appropriately according to the work range.

In this embodiment, since only the link mechanism is used to drive the passive rotating part R ₃ ′, the whole working robot can be constructed easily and lightweight.

FIG. 14 is an explanatory diagram in the case where a balance mechanism such as a spring is added to the manipulator 1 in FIGS. 12 and 13. In FIG. 14, one end 3 of the spring 31
2 is fixed to the intersection of the first arm 2 and the link 53, and the other end 33 of the spring 31 is fixed to the intersection of the link 51 and the link 52. The spring 31 can reduce the torque of the first arm driving unit R ₂ .

[0041]

As described above, according to the present invention,
Along with the rotational movement of the first arm, the passive rotating unit connected to the fixed side of the first arm driving unit via the connecting mechanism rotates, and the passive rotating unit rotates the second arm. Therefore, the second arm can be rotated without providing the second arm driving section, and even when the second arm driving section is installed, the operating range of the second arm driving section can be suppressed to be small. it can.

Thus, the operation area of the second arm can be secured while the operation range of the second arm drive section is mechanically limited, and the arm and the working unit can be placed on the work surface and other obstacles. Collision can be mechanically prevented. In particular, in a work such as cleaning the windshield of a jumbo jet machine, the working unit can reach the windshield without mechanically substantially interfering with the machine body, and the operating range of the drive unit for the second arm can be increased. Also conventional 180
There is an effect that it can be realized at a few tens of degrees only when it is necessary.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of a work robot according to the present invention.

FIG. 2 is a perspective view of the work robot shown in FIG.

FIG. 3 is a diagram for explaining the operation of the passive rotating unit according to the first embodiment.

FIG. 4 is an explanatory diagram for comparing operating ranges of conventional work robots.

FIG. 5 is a diagram illustrating an operation range of the manipulator of the first embodiment.

FIG. 6 is a diagram showing a case where an operation range of the manipulator of the first embodiment is set according to the nose of a jumbo jet machine.

FIG. 7 is a diagram illustrating a self-weight balancing mechanism incorporated in the manipulator in the first embodiment.

FIG. 8 is a perspective view showing a second embodiment of the work robot according to the present invention.

FIG. 9 is a diagram for explaining the operation of the passive rotating unit according to the second embodiment.

FIG. 10 is a schematic view showing a modified example of the connecting mechanism of the second embodiment.

FIG. 11 is a diagram illustrating a self-weight balance mechanism incorporated in a manipulator in the second embodiment.

FIG. 12 is a perspective view showing a third embodiment of a work robot according to the present invention.

FIG. 13 is a diagram illustrating a balance mechanism incorporated in a manipulator in the third embodiment.

FIG. 14 is an explanatory diagram when a balance mechanism is added to the manipulator.

FIG. 15 is a perspective view showing a state of a windshield glass cleaning work of an aircraft by a conventional work robot.

[Explanation of symbols]

1 Manipulator 2 1st arm 3 2nd arm 4 Working unit 5 Fixed pulley 6 Followed pulley 7 Belt R ₁ Swing drive part R ₂ 1st arm drive part R ₃ 2nd arm drive part R ₃ 'Passive rotation part

Claims (4)

[Claims] 1. A work robot having a work unit for contacting a work surface at a tip of a manipulator to perform a work, wherein the manipulator includes at least a first arm and a second arm connected to each other, and a first arm of the first arm. It has a first arm driving part provided at a base end for rotationally driving the first arm, and a passive rotating part provided at a tip end of the first arm, and the passive rotating part drives the first arm. A working robot, which is connected to a fixed side of the unit via a connecting mechanism, and rotates with the rotational movement of the first arm to rotationally drive the second arm. 2. The working mechanism according to claim 1, wherein the connecting mechanism for connecting the first arm driving unit and the passive rotating unit is constituted by a belt mechanism, a gear mechanism, a link mechanism or a combination thereof. robot. 3. The work robot according to claim 1, wherein the second arm is rotationally driven via the second arm drive section. 4. The work robot according to claim 1, wherein the manipulator is provided with a self-weight balance mechanism for supporting the self-weight of the first arm or the second arm.