JPH0852676A - Manipulator position regulating device - Google Patents

Abstract

PURPOSE:To surely prevent interference between each part (hand part or the like) of a manipulator and an obstacle (workpiece or the like) even in the case of providing an obstacle arbitrarily changed in work space. CONSTITUTION:When a hand 3 is moved downward to bring a contactor 6 into contact with an upper end of a workpiece 4a, a pin 8, moved upward with the contactor 6, is detected by a limit switch 7, and based on this detection signal in a regulation plane arithmetic part 21, a plane, when occupied by a point end of the hand 3, is set as a regulated plane A, to output a data of representing this regulated plate A to a drive control part 23. As a result in the drive control part 23, operating each articulation of an arm is controlled so as to prevent moving a point end of the hand 3 lower than the regulated plane A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manipulator position regulating device, and is particularly useful when applied to a case where a work having a non-uniform height is grasped and conveyed by a manipulator hand.

[0002]

2. Description of the Related Art As a means for restricting the operating range of an industrial manipulator, that is, a position restricting means, a mechanical stopper for restricting a rotation angle for each joint of the manipulator by a mechanical structure is used as in a general industrial robot. An angle sensor is provided at each joint of the manipulator, and a soft limit for restricting the rotation angle of each joint by comparing the detection signals of these angle sensors with the initial set angle. Teach the working space to the manipulator in advance. To regulate the working space (or only the working plane), so-called teaching playback system or numerical control system, mechanical lower limit height mechanism, etc. to mechanically create a working space to regulate the manipulator position. There is a way.

[0003]

However, the position control means of the manipulator according to the above-mentioned prior art is premised on that the working space can be grasped in advance, that is, the position of the conveyor, the wall surface or the fence is constant. I am trying. For example, in the above method, the regulation plane of the work space (conveyor, wall surface, fence, etc.) that is known in advance is set numerically, and the operation of each joint of the manipulator is regulated based on this regulation plane. By doing so, the interference (contact) between the conveyor, the wall surface and the like and each part of the manipulator is prevented.

Therefore, when a work whose height is not constant is conveyed by a conveyor or when there is an external moving conveyor, obstacles (work, moving conveyor, etc.) fall within a preset regulation plane. As a result, the various parts of the manipulator (particularly the hand part provided at the tip of the manipulator) may interfere with the obstacle.

Therefore, the present invention has been made in view of the above-mentioned prior art, and the manipulator position regulation can surely prevent the interference between each part of the manipulator and the obstacle even when there is an obstacle which changes arbitrarily in the working space. The purpose is to provide a device.

[0006]

According to a first aspect of the present invention for achieving the above object, a predetermined portion of a manipulator is provided so as to come into contact with an obstacle when the predetermined portion approaches the obstacle. A contactor, provided in the predetermined portion,
An urging means for urging the contactor in a direction away from the predetermined portion, and the contactor comes into contact with the obstacle, and the reaction force at this time opposes the urging force of the urging means to prevent the predetermined portion. Detecting means provided in the predetermined part so as to detect the movement of the contactor when the contact part moves in the direction of, and a regulation for restricting the movement of the predetermined part in the obstacle direction based on a detection signal of the detecting means. And a regulation plane calculation section for calculating a plane and sending data representing the regulation plane to the drive control section of the manipulator.

A second structure of the present invention which achieves the above object is the above-mentioned first structure, in which the predetermined part of the manipulator is a drive part of the hand provided at the tip of the manipulator, and the obstacle is the hand. It is a work to be grasped and conveyed by the restriction plane, and the restriction plane is set such that the position of the hand regulated by the restriction plane is an optimum position for grasping the work.

[0008]

According to the first aspect of the present invention, even if an obstacle which is not predicted in advance enters the working space, when the predetermined portion of the manipulator approaches the obstacle, the contactor comes into contact with the obstacle. To do. Therefore, the contactor moves toward the predetermined portion, and the movement of the contactor is detected by the detecting means. As a result, the restriction plane is set based on the detection signal at this time, and the further movement of the predetermined portion toward the obstacle beyond the restriction plane is restricted. Thus, the interference between the predetermined portion and the obstacle is prevented.

Further, according to the present invention having the above-mentioned second structure, interference between the drive unit of the hand and the work is prevented and the hand is made to work on the basis of the restriction plane as in the case of the first structure. It is positioned at the optimum position to grab.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a structural view showing a manipulator position regulating device according to an embodiment of the present invention, FIG. 2 (a) is an enlarged structural view showing the hand portion shown in FIG. 1, and FIG. 2 (b) is FIG. (A)
FIG. 3 is a cross-sectional view taken along the line X-X in FIG. 3, and FIG. In these figures, 1 is a manipulator body, 2 is an arm, 3 is a hand, 4a, 4b, 4c,
4d is a work, 5 is a hand drive unit, 6 is a contactor, 7 is a limit switch, 8 is a pin, 9 is a compression spring, 10 is a connecting member, 11 is a supporting member, 12 is a guiding member, 12a is a hole,
Reference numeral 13 is a conveyor, 21 is a restriction plane calculation unit, 22 is a storage unit, and 23 is a drive control unit.

As shown in FIG. 1, the manipulator body 1
Has a hand drive unit 5 at the tip of its arm 2 and a hand 3 at the lower end of the hand drive unit 5 in the figure. Therefore, the joints of the arm 2 are rotated to control the position of the hand 3, and the hand drive unit 5 opens and closes the hand 3.

As shown in FIG. 2A, the contact 6 is fixed to the tip of the connecting member 10 (the lower end in the figure) and occupies the middle of both hands 3. Further, the contact 6 is shown in FIG.
As shown in (b), each position is occupied with a space slightly wider than the narrow part of the hand 3 in order to avoid interference with the hand 3.

As described above, the contact member 6 of the connecting member 10 is fixed to the distal end portion thereof, and the proximal end portion thereof is inserted into the tubular guide member 12 fixed to the lower end portion of the hand driving unit 5. ing. The guide member 1 is provided at the base end of the connecting member 10.
The tip portion (lower end portion in the figure) of the compression spring 9 provided inside 2 is coupled, and the pin 8 is fixed.

Therefore, the contact 6 and the pin 8 are connected to the connecting member 10.
At the same time, it is urged by the compression spring 9 in the direction away from the hand drive unit 5, that is, in the tip direction of the hand 3. Further, the pin 7 has a hole 12a having both ends formed in the outer peripheral portion of the guide member 12 so as to have a predetermined length along the longitudinal direction thereof.
To the outside of the guide member 12. Therefore, an upward force in FIG. 2 acts on the contact 6 against the biasing force of the compression spring 9, and when the compression spring 9 contracts due to this force, the pin 8 is guided by the hole 12a and the hand drive unit 5 is pressed. Direction of
That is, it moves upward in FIG.

The limit switch 7 is supported by the front end (lower end in the figure) of a support member 11 whose base end is fixed to the lower end of the hand drive unit 5, and the pin 8 moves upward as described above. It is arranged to detect this pin 8 (actuate a switch) when a predetermined position is reached.

As shown in FIG. 1, the regulation plane calculation unit 21 stores the initial regulation plane A ₀ (conveyor 1) from the storage unit 22 in the initial stage (before the unique regulation plane is set for each work).
Data representing the plane on which the upper surface of 3 is occupied and output to the drive control unit 23, while the hand 3 moves downward and the contact 6 moves the workpiece 4a on the conveyor 13.
When the limit switch 7 detects this pin 8 when the pin 8 is moved upward together with the contact 6 by the reaction force of the work 4a at this time, the limit switch 7 calculates based on this detection signal. The plane in which the tip of the hand 3 is occupied is set as a new regulation plane A, and data representing this regulation plane A is output to the drive control unit 23.

The drive control unit 23 controls the operation of each joint of the arm 2. At this time, when data of the regulation plane, for example, data of the regulation plane A is input from the regulation plane calculation unit 21,
After that, the operation of each joint is controlled so that the tip of the hand 3 does not move below the restriction plane A.
The restriction plane A is the minimum height required for the hand 3 to grab the work 4a after that and to convey the work between two points 10
It turns off when it is lifted to 0 mm or more.

Therefore, according to the manipulator position regulating device of the above embodiment, as shown in FIG. 3, the regulating plane A is set for the work 4a, and the regulating plane A allows the hand 3 to move downward. Regulated. Next work 4a
When the work 4b that is shorter than the work 4 is conveyed by the conveyor 13, the contact switch 6 contacts the upper end of the work 4b and the limit switch 7 detects the pin 8 that moves upward together with the contact 6. New regulation plane B based on the detection signal (the plane at which the tip of the hand 3 is occupied at this time)
Is set, and the downward movement of the hand 3 is regulated by the regulation plane B. Similarly, when the work 4c or 4d having a different height is conveyed, a new restriction plane C or D corresponding to the respective work 4c or 4d is set, and these restriction planes C or D are set. The downward movement of the hand 3 is restricted.

Therefore, even if the heights of the works 4a to 4d are different from each other, the interference between the works 4a to 4d and the lower end of the band drive unit 5 is surely prevented, and they may be damaged. Disappear. Further, by adjusting the mounting positions of the contactor 6, the limit switch 7 and the like, the adjustment at the time of calculation in the restriction plane calculation unit 21, etc., the restriction planes A to D are changed to the positions of the hand 3 restricted by these restriction planes A to D. Is set to be the optimum position for grasping each of the works 4a to 4d, the positioning of the hand 3 can be accurately performed in a short time, and the defective gripping of the works 4a to 4d is eliminated.

In the above-mentioned embodiment, the case where the contactor 6 and the like are provided around the hand 3 which frequently comes into contact with the work or the like has been described, but of course the invention is not limited to this.
The contactor 6 or the like may be provided on any portion of the manipulator body 1 to prevent interference between these portions and obstacles or the like.

Further, in the above embodiment, the limit switch 7 is used as a detecting means for detecting the movement of the pin 8, that is, the movement of the contact 6, but it is of course not limited to this and the movement can be detected. I wish I had it. For example, a proximity switch or an optical switch may be used.

[0023]

According to the present invention as specifically described in connection with the above embodiments, since the movement of the predetermined portion of the manipulator in the direction of the obstacle is regulated by the regulation plane, the predetermined portion and the obstacle are prevented. Interference with is reliably prevented. Further, the predetermined part is a drive part of the hand, the obstacle is a work, and the regulation plane is set so that the position of the hand regulated by the regulation plane is an optimal position for grasping the work. In addition, the positioning of the hand can be performed accurately in a short time, and the defective gripping of the work is eliminated.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a manipulator position regulating device according to an embodiment of the present invention.

2A is an enlarged configuration diagram showing the hand unit shown in FIG. 1, and FIG. 2B is a sectional view taken along line XX of FIG.

3 is an explanatory diagram showing a state in which various kinds of works having different heights are gripped by the hand shown in FIG. 1. FIG.

[Explanation of symbols]

 1 Manipulator Main Body 2 Arms 3 Hands 4a to 4d Work 5 Hand Drive Unit 6 Contact 7 Limit Switch 8 Pin 9 Compression Spring 10 Connecting Member 11 Supporting Member 12 Guide Member 12a Hole 13 Conveyor 21 Regulation Plane Calculation Unit 22 Storage Unit 23 Drive Control Department

Claims (2)

[Claims] 1. A contact provided on a predetermined portion of the manipulator so that the predetermined portion of the manipulator comes into contact with the obstacle when the predetermined portion approaches the obstacle, and the contact provided on the predetermined portion. An urging means for urging in a direction away from the contact element, the contactor comes into contact with the obstacle, and when a reaction force at this time moves in the direction of the predetermined portion against the urging force of the urging means, Detecting means provided in the predetermined part so as to detect the movement of the contact, and a restriction plane for restricting the movement of the predetermined part in the obstacle direction are calculated based on the detection signal of the detecting means, and the restriction plane is calculated. A manipulator position restricting device, comprising: a restricting plane calculating part for sending data representing a plane to a drive controlling part of the manipulator. 2. The manipulator position regulating device according to claim 1, wherein the predetermined part of the manipulator is a drive part of a hand provided at the tip of the manipulator, and an obstacle is a work which is grasped and conveyed by the hand. The manipulator position regulating device, wherein the regulating plane is set so that the position of the hand regulated by the regulating plane becomes an optimum position for grasping the work.