JPH06297364A - Positioning device - Google Patents

Abstract

(57) [Abstract] [Purpose] To align two constrained members without much effort. [Structure] The two-arm robot 5 is provided with two refrigerant pipes 1 and 2 which are bound by an air conditioner.
When fitting each other with each other, the rigidity of each of the pipes 1 and 2 is detected by giving a slight displacement to each of them, and the output torque of each of the two arms of the robot holding each of the refrigerant pipes 1 and 2 is detected. By calculating in advance the positions where the pipes 1 and 2 can be arranged facing each other in the matched state, the alignment and fitting of the pipes 1 and 2 can be done without requiring a large output torque on one arm. To be able to.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position of members which are constrained by connecting one end to another member such as a refrigerant pipe in a state before being fitted at the time of assembling an air conditioner. The present invention relates to a device for performing matching.

[0002]

2. Description of the Related Art Conventionally, assembling work of an air conditioner requires fitting work of pipes as disclosed in, for example, Japanese Utility Model Laid-Open No. 63-108058. Then, as one of the fitting works of such pipes, there is a work of fitting the refrigerant pipe whose one end is connected to the compressor and the refrigerant pipe whose one end is connected to the heat exchanger. Until now, such work has been performed manually by a worker or by a work robot. Specifically, as shown in FIG. 7, one refrigerant pipe
(a) is fixed by a jig (c) or the like, and the fixed refrigerant pipe (a) is fitted with the other refrigerant pipe (b).

[0003]

However, in such fitting work of the pipes (a) and (b), depending on the arrangement position of each device, the length of each pipe, the bent shape, etc., the pipe (a ),
There is a displacement between the open ends of (b) (see the solid line in Fig. 7). In such a case, the fitting side pipe (b) is largely elastic to the fixed side pipe (a) installation position. A situation may arise in which the pipe (a) on the fixed side must be fitted while being deformed (see the phantom line in FIG. 7).
In other words, the movement of the pipe (b) on the mating side is restricted by the air conditioning equipment (heat exchanger, etc.),
It has to be moved to the position where the fixed side pipe (a) is arranged against this restraining force, and in such a case, a great deal of labor is required by the operator. Further, in the case where such work is performed by the articulated robot (d), a high output robot is required, and there is a problem that this fitting work cannot be performed unless it is a large robot.

The present invention has been made in view of this point, and an object of the present invention is to obtain a structure that enables the two members to be aligned with each other without requiring a great deal of labor.

[0005]

In order to achieve the above object, the present invention is configured to move each of the two constrained members by a moving amount according to the rigidity thereof for alignment. The invention according to claim 1 is directed to an apparatus for aligning predetermined portions of the first member (1) and the second member (2) whose free movements are restricted with each other. Then, the first moving means (6) for holding the first member (1) and moving the first member (1) against the restraining force, and adjusting the output of the first moving means (6) First output adjusting means (10), and the first member
First position detecting means (12) for detecting the position of (1) and first rigidity detecting means (14) for detecting the rigidity of the first member (1) are provided. Further, the second member (2) is grasped and the second member
Second moving means (7) for moving the member (2) against the restraining force
A second output adjusting means (11) for adjusting the output of the second moving means (7); a second position detecting means (13) for detecting the position of the second member (2); Second rigidity detection means (15) for detecting the rigidity of the member (2) is provided. Then, receiving the respective detection signals of the first position detecting means (12), the second position detecting means (13), the first rigidity detecting means (14) and the second rigidity detecting means (15), the first output adjustment When the output of the first moving means (6) adjusted by the means (10) and the output of the second moving means (7) adjusted by the second output adjusting means (11) are equal, the first member (1 ) And the alignment position calculating means (16) for calculating the position at which the predetermined parts of the second member (2) are aligned with each other.

According to a second aspect of the invention, in the alignment device according to the first aspect, when the first member (1) and the second member (2) are tubular bodies and their open ends are fitted to each other, The open ends are aligned with each other.

[0007]

With the above-described structure, the following effects can be obtained in the present invention. In the invention according to claim 1, the position signal of the first member (1) from the first position detecting means (12), the position signal of the second member (2) from the second position detecting means (13), the first signal The rigidity signal of the first member (1) from the rigidity detecting means (14) and the rigidity signal of the second member (2) from the second rigidity detecting means (15) are transmitted to the alignment position calculating means (16). The alignment position calculating means (16) is adjusted by the output of the first moving means (6) adjusted by the first output adjusting means (10) and the second output adjusting means (11) based on each signal. The position where the predetermined parts of the first member (1) and the second member (2) are aligned with each other is calculated with the output of the second moving means (7) being equal. As a result, the predetermined parts of the first member (1) and the second member (2) can be aligned with each other while equalizing the output of the first moving means (6) and the output of the second moving means (7). Therefore, it is possible to prevent a large amount of output from being required for only one of the moving means.

According to the second aspect of the invention, the open ends of the first member (1) and the second member (2), which are tubular bodies, are fitted to each other with their open ends aligned with each other. A smooth fitting operation can be performed.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment of the present invention will be described with reference to the drawings. Further, in this example, the refrigerant pipe of the air conditioner will be described as an example of the two constrained members. As shown in FIGS. 1 and 2, the refrigerant pipes as the two constrained members in this example have a first pipe (1) as the first member connected to the compressor (3) at one end and an end at the other end. A second pipe (2) as a second member connected to the heat exchanger (4), wherein the second pipe (2) is fitted to the first pipe (1). .

FIG. 3 shows a double-arm robot (5) for fitting the pipes (1) and (2). This dual-arm robot (5) comprises a first robot (6) as the first moving means according to the present invention and a second robot (7) as the second moving means according to the present invention. As shown in FIG. 3, the first robot (6) grips the open upper edge of the first pipe (1) and the second robot (7) grips the open lower edge of the second pipe (2). Then, after the pipes (1) and (2) are aligned with each other, they are fitted to each other. That is, as shown in FIG. 2, the open ends of the pipes (1) and (2) are arranged at a small distance in the vertical direction and slightly offset in the horizontal direction. (6),
The drive in (7) corrects the positional deviation in the horizontal direction, performs alignment, and then fits.

Next, details of the dual-arm robot (5) will be described. Since the first robot (6) and the second robot (7) have substantially the same configuration, here the first robot (6)
An explanation will be given by taking (6) as an example. As shown in the schematic view of the arms (6a) to (6f) of the robot (6) shown in FIG.
(6) is a 6-axis control type, that is, it has joints (6g) to (6m) at 6 locations, and controls the output torque of each of the 1st to 6th joints (6g) to (6m) to position the hand. Is set to a predetermined position. An encoder (not shown) is provided at each joint (6g) to (6m), and the rotation angle of the joint is detected, and the coordinates of the hand are detected based on these rotation angles. ing. Specifically, the coordinate system of this hand is described. The origin of the arm of the robot (6) is the origin O.
Let (x, y, z) be the coordinate point of the hand with respect to the three-dimensional coordinate of X, Y, Z, and the coordinate point (x, y, z) of this hand.
A straight line W obtained by projecting the arm (6e, 6f) connected to the hand onto a plane including the X'axis and the Y'axis with respect to the three-dimensional coordinates of X ', Y', and Z'having an origin O '. And the angle between the X'axis and ρ,
The angle formed by the arm (6e, 6f) connected to the hand on the plane including the straight line W and the Z ′ axis and the Z ′ axis is θ, and the sixth joint (6
Let φ be the angle of rotation from the reference state position in m). As a result, the hand coordinate system of the first robot (6) has six coordinate points (x,
y, z, ρ, θ, φ).

Next, the control operation of this apparatus will be described. The control of this device depends on the rigidity of each pipe (1), (2).
Each pipe whose position coordinates match (1), (2)
The amount of displacement at the ends of (1) and (2) is obtained, and the output torque of each joint is controlled to obtain this amount of displacement. This operation will be described with reference to the flowchart of FIG.

After the start, first, in step ST1, the rotation angle of each joint, that is, each joint coordinate is detected by the encoder. After that, the process moves to step ST2 and the joint coordinates detected in step ST1 are converted into the coordinates of the hand to recognize the position of the hand. After that, move to step ST3, slightly drive each robot (6), (7), and pipe (1),
A small displacement is added to (2) to calculate the amount of change in output torque, and in step ST4, this displacement and the robot (6),
Determine the stiffness of each pipe (1), (2) at each hand coordinate based on the amount of change in output torque in (7). Then, in step ST5, the point (fitting position) where the output torques of the robots (6) and (7) match and the position coordinates of the pipes (1) and (2) match (the fitting position) is expressed by the following formula ( This formula is for finding the coincident point in the X coordinate). km (xm-xo) = ks (xo-xs) (km: coefficient indicating the rigidity of the first pipe in the X-axis direction, xm:
Current position coordinates of the open end of the first pipe, xo: Coordinate point of the fitting position on the X-axis coordinate of the first pipe and the second pipe, ks:
Coefficient indicating the rigidity of the second pipe in the X-axis direction, xs: current position coordinate of the open end of the second pipe) When this formula is expanded to obtain the coordinate point of the fitting position on the X coordinate, xo = ( km · xm + ks · xs) / (km + ks) ...... Similarly, the first pipe in the other five coordinate systems
Find the coordinate point of the fitting position of (1) and the second pipe (2).
First pipe (1) and second pipe (2) obtained in this way
At the coordinate point of the fitting position of, the robots (6) and (7) can align the pipes with each other with the same output torque, so in step ST6, the pipe (1), Each robot (6), so that the open end of (2) is positioned,
The output torque of each joint in (7) is controlled. The output of each joint in each robot is obtained by the following determinant. τ = −J (q) · K · J (q) · Δq (= Δd = −F) (τ: column vector of output torque command, J (q): Jacobian matrix (6 × 6 matrix), K : Hand stiffness matrix (6
X6 matrix), Δq: column vector of (joint angle-target value of joint angle), Δd: column vector of amount of hand-shake, -F: external force applied to the hand) The conversion state of the signal based on this mathematical formula is shown in FIG. Shown in block diagram. That is, the joint coordinates are converted into the coordinates of the hand by the Jacobian matrix J (q), then the external force F related to the hand is calculated based on the stiffness matrix K of the hand, and then the joint matrix is transposed by the transposed matrix of the Jacobian matrix. The torque command vector of the motor is obtained, and the robot is driven based on this command vector.

Therefore, by rotating the joints with the output torque, the open ends of the pipes (1) and (2) are arranged close to each other (see the phantom line in FIG. 2). ) Then, the first pipe (1) is fitted to the second pipe (2) by moving the pipes (1) and (2) close to each other. Therefore, in the flowchart of FIG. 5, the first position detecting means (12) and the second position detecting means (13) of the present invention are configured in step ST2, and the first rigidity detecting means (of the present invention in step ST4 14) and the second stiffness detecting means (15), the alignment position calculating means (16) according to the present invention is configured at step ST5, and the first output adjusting means (10) according to the present invention at step ST6. Second output adjusting means (11)
And are configured. In the fitting operation described above, the hand rigidity is set high in the direction in which the pipes (1) and (2) are close to each other, and the hand rigidity is set low in the other directions, so that a slight deviation occurs. Even if it occurs, so-called compliance control is performed so that smooth fitting can be performed while correcting the trajectory.
That is, the contact force between the pipes at the time of fitting the pipes together is detected, and the pipes are fitted together while the trajectory is corrected based on the contact force.

Thus, according to this example, the first robot
When the output torque at each joint of (6) and the output torque at each joint of the second robot (7) are equal, the first piping
Since the position where the open ends of (1) and the second pipe (2) are aligned with each other is calculated in advance, the first robot
It is possible to position the first pipe (1) and the second pipe (2) while making the output of (6) and the output of the second robot (7) equal, so that one robot needs a large output. It never happens. Therefore, as in the prior art, one of the pipes is fixed in advance, and the robot with a smaller output than the one in which the other pipe is fitted to the fixed pipe enables this fitting, It is possible to reduce the size and cost of the robot. Further, when the present invention is adopted for the fitting work of the refrigerant pipes (1) and (2) as in this example, a smooth fitting operation can be performed, and the work efficiency is improved. Can be planned.

In this example, the refrigerant pipes (1) and (2) of the air conditioner were described as an example of the two restrained members, but the present invention is not limited to this, and other pipes and It can be applied to various members such as two plate materials that are welded to each other.

[0017]

As described above, according to the present invention, the following effects are exhibited. According to the first aspect of the present invention, the device for aligning the predetermined parts of the first member (1) and the second member (2) whose free movements are restricted with respect to each member (1), The first to detect the position of (2)
Position detecting means (12) and second position detecting means (13), each member
The first stiffness adjusting means (14) which receives the detection signals of the first stiffness detecting means (14) and the second stiffness detecting means (15) for detecting the stiffness of (1) and (2), and which is adjusted by the first output adjusting means (10) Second moving means adjusted by the output of the moving means (6) and the second output adjusting means (11)
The first member (1) and the second member with the output of (7) being equal.
The output of the first moving means (6) and the second moving means (7) are provided because the alignment position calculating means (16) for calculating the position where the predetermined parts of (2) are aligned is provided. The predetermined parts of the first member (1) and the second member (2) can be aligned with each other while making the output of the same, and a large output is not required for only one moving means. Since the positioning can be performed by the small moving means (6), (7), the moving means (6), (7) can be downsized and the cost can be reduced.

According to the invention described in claim 2, the first member
The (1) and the second member (2) are tubular bodies, and when the open ends are fitted together, the open ends are aligned, so that a smooth fitting operation can be performed. ,
Work efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a refrigerant piping state before being fitted.

FIG. 2 is a view showing a peripheral portion of an open end of a pipe.

FIG. 3 is a diagram showing a dual-arm robot.

FIG. 4 is a schematic view of each arm of the robot.

FIG. 5 is a flowchart showing an alignment operation.

FIG. 6 is a block diagram showing an alignment operation.

FIG. 7 is a diagram showing a conventional pipe fitting operation.

[Explanation of symbols]

 1 1st piping (1st member) 2 2nd piping (2nd member) 6 1st robot (1st moving means) 7 2nd robot (2nd moving means) 10 1st output adjusting means 11 2nd output adjusting means 12 First Position Detecting Means 13 Second Position Detecting Means 14 First Rigidity Detecting Means 15 Second Rigidity Detecting Means 16 Aligned Position Calculating Means

Claims (2)

[Claims] 1. A first member which is restrained from freely moving with respect to each other.
A device for aligning predetermined parts of (1) and two members (2) with each other, wherein the first member (1) is gripped and the first member (1) is moved against a restraining force. First moving means (6) for making the first moving means
First output adjusting means (10) for adjusting the output of (6), first position detecting means (12) for detecting the position of the first member (1),
First rigidity detecting means (1) for detecting the rigidity of the first member (1)
4), second moving means (7) for holding the second member (2) and moving the second member (2) against the restraining force, and the second moving means
Second output adjusting means (11) for adjusting the output of (7), second position detecting means (13) for detecting the position of the second member (2),
Second rigidity detection means (1) for detecting the rigidity of the second member (2)
5) and the respective detection signals of the first position detecting means (12), the second position detecting means (13), the first rigidity detecting means (14) and the second rigidity detecting means (15), The output of the first moving means (6) adjusted by the output adjusting means (10) and the second output adjusting means (1)
Aligned position calculating means for calculating the position where the predetermined parts of the first member (1) and the second member (2) are aligned with each other in a state where the output of the second moving means (7) adjusted by 1) is equal. (16)
An alignment device comprising: 2. The first member (1) and the second member (2) are tubular bodies, and when the open ends thereof are fitted together, the open ends are aligned with each other. The alignment device according to claim 1, wherein: