JP2001205584A - Robot hand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot hand capable of picking a work without interference with and damage to the other works, approaching it in response to working attitude, and picking any type of work. SOLUTION: A hand body 2a at the end of an arm 1 of a robot is provided with attracting means having an attraction part for attracting a work 4 to the end of an inclinable rod 6a, elevating means having a driving part for elevating up and down the attracting means, work measuring means for measuring the position and attitude of the work 4, stroke adjusting means for computing and controlling the amount of pull-up stroke in pulling the work 4 up in accordance with measurement information from the work measuring means, attitude stabilizing means for inhibiting the vibration of the work 4, after attracted, and stabilizing the attitude thereof, and angle difference absorbing means for absorbing an angle difference between the normal line of the attracted face of the work 4 and the normal line of the rod 6a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a robot hand of a robot for supplying a work stacked in bulk to an assembly / machining line which is factory-automated (FA).

[0002]

2. Description of the Related Art Conventionally, as this kind of robot apparatus, there is one disclosed in Japanese Patent Application Laid-Open No. H11-123681, which is configured as shown in FIGS. First, the robot hand c and the robot arm d are moved so that the container imaging camera a is positioned above the pile of containers b, and an image captured from the container imaging position is output from the container imaging camera a to the hand control device e. Is done. The hand control device e performs predetermined image processing on the captured image and compares the processed captured image with a previously stored component image of a single component. Outputs position information and posture information of the component f whose area is estimated. Then, the arm control device g operates the robot arm d based on the information. As described above, by the cooperative operation of these control devices, the robot hand c is moved so that the estimated component position is located between the claws h, h of the robot hand c, and then the claws h, h
Close. As a result, when the limit sensor i does not detect contact between the claws h, h, the component f
Is determined, the robot hand c and the robot arm d are moved to move the part f to the posture detection table j. Thereafter, the claws h and h are opened, and the component f is placed on the posture detection table j.

When the component f is placed on the attitude detection table j, a captured image of the attitude detection table j is output from the table imaging camera k to the image processing device m. This image processing information performs predetermined image processing on the image, compares the processed captured image with a previously stored component image of a component alone, and extracts an image region having similarity to the component image, From this, estimated position information and estimated posture information of the component f are output. As a result, the robot hand c and the robot arm d are controlled so as to clamp the component f in a predetermined direction, and thereafter, the component f can be placed at a predetermined position of the unloading container n in a predetermined direction.

[0004]

In the robot hand of the above-mentioned conventional robot, since the claws directly approach the work, which is a component stacked in the stacking container, the claws and the tip of the robot hand are not provided. It may interfere with other works or cause damage. Further, since the approach of the robot hand is in a predetermined direction with respect to the work posture, there is a problem that it is impossible to approach a work near a wall of a pile of containers or a work with a large inclination angle.

The present invention has been made in view of the above description, and allows picking without interfering with or damaging other works, and furthermore, any work that can be approached according to the work posture. However, an object is to provide a robot hand that can pick.

[0006]

According to a first aspect of the present invention, there is provided a robot hand for bin picking, comprising: a suction unit having a suction portion for suctioning a workpiece to a tip of a tiltable rod; Lifting / lowering means having a drive unit capable of raising / lowering the suction means, work measuring means for measuring the position and orientation of the work, and calculating / controlling a lifting stroke amount for lifting the work based on information measured by the work measuring means. Stroke adjusting means, posture stabilizing means for suppressing vibration of the work after suction and stabilizing the posture, gripping means having a plurality of claws, and an angle between a normal direction of a suction surface of the work and a normal direction of the rod. An angle difference absorbing means for absorbing a difference is provided on the hand body at the tip of the robot arm. The work can be attracted to the suction means and pulled up to a safe area where it does not interfere with the surrounding work, and the posture of the work can be stabilized by the posture stabilizing means and the work can be gripped by the gripping means. By gripping the work in this manner, bin picking can be performed without damaging the surrounding work because the work is lifted to a safe area without directly gripping and then gripped. In addition, the position and orientation of the work are measured by the work measuring means, and the stroke amount for lifting the work is calculated based on the information measured by the work measuring means, and the stroke amount for lifting is adjusted to limit the shape, position and posture of the work to be lifted. There is no versatility. By having an angle difference absorbing means for absorbing the angle difference between the normal direction of the suction surface of the work and the normal direction of the rod, even for a work near the wall of a container in which the work is piled up or a work that is greatly inclined, The lifting can be performed by suction from the vertical direction, and all the workpieces inside the container can be picked.

According to a second aspect of the present invention, in the robot hand according to the first aspect, when the inclination angle of the workpiece measured by the workpiece measuring means exceeds a preset threshold value, the inclination angle of the rod is set to the threshold value. It is characterized by having a control means for controlling the work so as to approach and attract the work while the work is fixed. Up to a certain threshold, the rod can be tilted accordingly to approach the workpiece and be attracted, but if it exceeds a certain threshold, the rod can be approached and sucked without further tilting the rod. it can. That is, if the inclination angle of the work becomes large, there is a risk that the hand or the arm may interfere with the surrounding work or the container, but this can be avoided by performing the control as described above. In addition, such control eliminates the need for forcing the robot to take an unreasonable posture, so that the movable range is widened, and pickup at the wall of the container becomes possible.

According to a third aspect of the present invention, there is provided a robot hand according to the first or second aspect, wherein the hand body approaches the work near the wall around the container from the vertical direction regardless of the inclination of the work. Control means is provided for controlling the work to be picked up again after the work is moved to the vicinity of the center of the container while being sucked by the lifting means. The hand body approaches the work from the vertical direction and adsorbs the work to the work near the wall of the container.In this state, the hand body is moved together with the work to the center of the container, and the work picking up work is started again from this state. It is controlled to restart. Thereby, the work near the wall of the container is also reliably picked up.

According to a fourth aspect of the present invention, there is provided the robot hand according to any one of the first to third aspects, wherein the closing width of the gripping means for gripping the workpiece is smaller than the workpiece size and reaches the closed limit. It is provided with a detection means for detecting the position, and a control means for controlling that the pick-up operation is restarted again when it is determined that the gripping of the work has failed when the detection means operates after the work is lifted. Success or failure of gripping by the workpiece gripping means can be determined with a simple structure. In addition, when the gripping of the workpiece fails, the pick-up operation can be restarted. In the case of the gripping failure, a useless operation of moving the robot hand to the place position can be eliminated, and the tact time can be reduced.

According to a fifth aspect of the present invention, there is provided a robot hand according to any one of the first to fourth aspects, wherein the gripping means for gripping the workpiece has compliance so that even if the workpiece has a tapered surface. The workpiece is gripped while the gripping surface follows the tapered surface. It is possible to reliably grip a tapered work or a work having a complicated shape.

According to a sixth aspect of the present invention, there is provided a robot hand according to any one of the first to fifth aspects, wherein a flat plate is provided as a posture stabilizing means at a predetermined position, and the work is attracted and pulled up by the lifting means. At this time, the posture after the lifting by the flat plate is stabilized by pulling up to the position of the flat plate. When the adsorbent of the lifting means approaches the work, there is no object other than the adsorber, so that even a work having a complicated shape or a work having a rib or the like on the surface can be sucked and lifted. Further, since the posture of the work is stabilized by applying the work to the flat plate, the contact area with the work when stabilizing the posture is large, and the posture stability of the work after being pulled up is high.
In addition, even if there are irregularities on the suction surface of the work, the posture of the work after lifting is stabilized.

According to a seventh aspect of the present invention, in the robot hand according to any one of the first to fifth aspects, after the adsorber of the lifting means is caused to approach the work, the suction force of the adsorber is smaller. Attitude stabilizing means for raising the work while maintaining the posture of the work by blowing air onto the work is provided. It is possible to stabilize the posture of the work without blowing air, and there is no danger of damaging the work. In addition, when the adsorber approaches the work, there is no object other than the adsorber, so that a work having a complicated shape or a work having a rib or the like on the surface can be sucked and lifted.

The robot hand according to claim 8 of the present invention is the robot hand according to any one of claims 1 to 5, wherein the adsorbent of the lifting means is made to approach the workpiece to the work as a posture stabilizing means around the adsorber. By setting up the work, the work is pulled up while keeping the posture of the work stable. If a position distant from the center of gravity of the work is sucked, the work is lifted while being inclined, and there is a risk of falling, but this can be avoided. In addition, the workpiece can be lifted in a stable state without fluctuation.

According to a ninth aspect of the present invention, in the robot hand according to the first to fifth aspects, a plurality of pins serving as posture stabilizing means are provided around the attraction element when the suction element of the lifting means approaches the work. It is characterized in that the work is lifted up while keeping the posture of the work stable. Since the position of the pin for stabilizing the posture of the work can be arbitrarily adjusted, it is possible to arrange the pin for stabilizing the posture of the work according to the size and shape of the work. Further, if a position away from the center of gravity of the work is sucked, the work is lifted while being inclined, and there is a risk of falling, but this can be avoided.

According to a tenth aspect of the present invention, in the robot hand according to the sixth aspect, the lifting of the attraction element by the lifting means can be stopped in a stepwise manner. Even if the workpiece has a concave surface like a channel, the posture can be stabilized by adjusting the lifting amount.

The robot hand according to claim 11 of the present invention is characterized in that in claim 6, the robot hand is provided with elevating means for elevating and lowering the work gripping means, and the gripping means is positioned above the flat plate until the work is raised to the flat plate position. Then, after the work is pulled up to the position of the flat plate, the holding means is lowered to hold the work. The lifting stroke of the adsorber can be increased. Further, it is possible to prevent the gripping means from interfering with the surrounding work and damaging the work.

According to a twelfth aspect of the present invention, there is provided a robot hand according to the sixth aspect, wherein a flat plate is provided via an elastic body so as to provide compliance in a work lifting direction. The risk of damaging the hand or the work can be avoided even when the hand approaches the hand slightly due to the measurement error of the work or when the surrounding work is higher than the target work.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the basic structure shown in FIG. 1 will be described. FIG. 1A is a perspective view showing the structure of a robot hand according to the present invention and a picking method using the same, and FIG. 1B is a perspective view showing a more specific embodiment of the robot hand. A hand 2 is connected to the distal end of the robot arm 1 so that an arbitrary work 4 among the works 4 stacked in a container 3 such as a container can be picked up and supplied to a predetermined position. ing.

The hand body 2a of the hand 2 is provided with gripping means for gripping the work 4, lifting means for lifting the work 4, means for stabilizing the posture of the work 4, and the like. In the case of the present example, the gripping means is formed by a pair of claws 5 which can be freely moved toward and away from each other, and is driven by the air cylinder 23. Then, the work 4 is positioned between the pair of claws 5 in a state where the pair of claws 5 are separated from each other, and the work 4 is moved between the pair of claws 5 by moving the pair of claws 5 closer to each other.
Can be grasped. The lifting means includes an adsorber 6 and an elevating means for moving the adsorber 6 up and down. The adsorber 6 is a rod 6a that can move up and down.
Pad 6 as a suction means provided with a suction section at the lower end of the device
b is provided. In the case of this example, the means for stabilizing the posture is formed of the flat plate 8, and the vibration of the work 4 is suppressed by applying the work 4 to the flat plate 8 to stabilize the posture. In addition, it has a work measuring means for measuring the position and posture of the work when sucking and lifting the work. The work measuring means is, for example, a camera or a laser. Further, it has a stroke adjusting means for calculating and controlling a stroke amount to be lifted by the elevating means based on information measured by the work measuring means.

The bin picking of the workpieces 4 bulk loaded in the container 3 is performed as follows. Container 3
The hand 2 is moved to a predetermined position on the work, and in this state, the rod 6a is lowered, the suction pad 6b is pressed against the suction surface of an arbitrary work 4, and the work 4 is pressed onto the suction pad 6b by suction such as air suction. Is adsorbed. While the work 4 is being sucked to the suction pad 6b, the rod 6a is raised as shown by the arrow A in FIG. 1A, and the work 4 is raised to a safe area where the work 4 does not interfere with the surrounding work 4. When the work 4 is pulled up to a predetermined position, the work 4 hits the flat plate 8 and the work 4
Posture is stabilized. When the work 4 is pulled up to a predetermined height, the pair of claws 5 are moved so as to approach in the direction of arrow B in FIG. It is released. Since the work 4 is gripped between the pair of claws 5 in this manner, the picked-up work 4 is not directly gripped, but is picked up in a safe area and then gripped. Becomes possible. In addition, work 4
Then, the workpiece 4 can be gripped between the pair of claws 5 after stabilizing the posture of the workpiece 4 so that the workpiece 4 can be stably gripped between the claws 5 and can be gripped without damaging the workpiece 4. Further, the position and orientation of the work 4 to be lifted are measured by the work measuring means, and the stroke amount for lifting the work 4 is calculated based on the information measured by the work measuring means, and the stroke amount to be lifted is adjusted, so that the work 4 to be lifted is adjusted.
There is no limitation on the shape, position, or posture of the device, and it is versatile.

When the suction pad 6b is provided at the lower end of the rod 6a as shown in FIG. 1 (c), a bellows 9 is interposed at the lower end of the rod 6a. A sliding rod 7 is provided via a body 10, and the bellows 9 is attached to the lower end of the sliding rod 7. The bellows 9 is compliant with the posture angle difference between the hand 2 and the work 4 and the amount of pushing of the adsorber 6. I have. Thus, for example, in a bin picking system that measures the position and orientation of the work 4 using a camera or a laser, the hand 2 can absorb and pick up a measurement error. As described above, the work 4 on the wall of the container 3 or the work 4 having a large inclination is sucked from the vertical direction and pulled up by the means for absorbing the angle difference having the compliance, so that all the work inside the container 3 is lifted. 4 can be picked.

Next, an example of the embodiment shown in FIG. 2 will be described. This embodiment employs the following control means in the robot hand. When the inclination angle α of the workpiece 4 approaches the predetermined threshold ε, the rod 6a is approached by adjusting the inclination angle of the rod 6a in the normal direction D of the workpiece 4, but when the inclination angle α exceeds the preset threshold ε, the rod 6a Threshold angle ε
And control means for controlling the suction means so as to be attracted and approached while being fixed at the position. The arm 1 is moved to a position where the suction pad 6b hits the suction surface of the work 4 when the suction element 6 is lowered. At this time, as shown in FIG. 2A, when the inclination angle α of the work 4 is smaller than a certain threshold ε, the posture of the rod 6a is adjusted in the normal direction D of the suction surface of the work 4, Suction pad 6 in the direction
b is brought close to the suction pad 6b to be pulled up. However, when the inclination angle α of the work 4 is large, or when the work 4 is near the wall of the container 3 such as a container, FIG.
As shown in (c), there is a problem that the hand 2 or the arm 1 hits the wall of the container 3 and interferes (the part indicated by the symbol F is the part that interferes). Thus, when the inclination angle α of the work 4 exceeds a certain threshold ε, as shown in FIG. 2B, the rod 6a is approached to the suction pad 6b while keeping the inclination angle at the threshold ε to perform a pickup operation.
As a result, it is possible to overcome the above problem and to pick up all of the work 4 inside the container 3. That is,
If the inclination angle α of the work 4 becomes large, there is a risk that the hand 2 or the arm 1 may interfere with the surrounding work 4 or the container 3, but this can be avoided by controlling as described above.
In addition, this control eliminates the need to force the robot into an unreasonable posture, thereby increasing the movable range,
Pickup near the wall is also possible.

Next, an example of the embodiment shown in FIG. 3 will be described. This embodiment employs the following control means in the robot hand. Regardless of the inclination of the work 4, the hand main body 2a approaches the work 4 near the wall around the container 3 from the vertical direction, and the work 4 is moved to the vicinity of the center of the container 3 while the work 4 is being sucked by the lifting means. There is provided control means for controlling the work of picking up the work 4 again. In the case of the work 4 near the wall of the container 3, the work 4
When the posture of the hand 2 is inclined in accordance with the inclination angle of the hand 3, there is a problem that the hand 2 or the arm 1 interferes with the wall of the container 3. Therefore, as shown in FIG. 3A, regardless of the inclination angle of the work 4 with respect to the work 4 near the wall,
The hand 2 approaches from the vertical direction, adsorbs the work 4 to the adsorber 6, moves it to the vicinity of the center of the container 3 as shown in FIG. Thereafter, the pickup is performed again in the procedure described in the above example. Thereby, the work 4 near the wall of the container 3 is also reliably picked up.

Next, an example of the embodiment shown in FIG. 4 will be described. This embodiment employs the following control means in the robot hand. A detection means for detecting a position where the closing limit of the gripping means for gripping the work 4 is smaller than the work size and reaching the closed limit; There is a control unit that determines that the operation has failed and controls the pickup operation to restart again. As shown in FIG. 4, the width of the workpiece 4 is G, and the closing width of the claw 5 as a gripping means is H. A sensor 11 is installed as a detecting means at the closed position of the claw 5,
The sensor 11 is set to be turned on when the claw 5 reaches the closing limit. 4A, the sensor 11 is not turned on when the gripping of the workpiece 4 is successful as shown in FIG. 4A, and the sensor 11 is turned on when the gripping is unsuccessful. Failure can be determined. For example, when performing a pick-and-place operation, if an unsuccessful grasp is confirmed, the operation of moving the robot arm 1 to the place position can be eliminated, and the tact time can be reduced. By controlling as described above, the success or failure of the gripping of the work 4 by the gripping means can be determined with a simple structure. In addition, when the gripping of the work 4 fails, the pick-up operation can be restarted again. In the case of the gripping failure, a useless operation of moving the robot hand 2 to the place position can be eliminated, and the tact time can be reduced.

Next, an example of the embodiment shown in FIG. 5 will be described. In this example, the following means was employed in the robot hand. By making the gripping means for gripping the work 4 compliant, even if the tapered surface 12 exists in the work 4, the work 4 is gripped while the gripping surface follows the tapered surface 12. If the tapered surface 12 exists on the gripping surface of the work 4, the claws 5 hit against the work 4 as shown in FIG.
Therefore, as shown in FIG.
1 is rotatably supported so as to rotate about 1, and both ends thereof are restrained by an elastic body 15 such as a spring. And claw 5
Is closed, the gripping body 13 follows the tapered surface 12 of the work 4 so that the work 4 can be reliably held. By doing so, it is possible to reliably grip the work 4 having a taper or the work 4 having a complicated shape.

Next, an example of the embodiment shown in FIG. 6 will be described. In this example, the following means was employed in the robot hand. Placing the flat plate 8 at a predetermined position as posture stabilizing means,
When the work 4 is attracted and pulled up by the lifting means, the work 4 is raised to the position of the flat plate 8 so that the posture after the lifting by the flat plate 8 is stabilized. The adsorbent 6 is vertically movable by the elevating means 14, and the flat plate 8 is installed at a position where the adsorbent 6 is pulled up.
The rod 6a is inserted through the through hole 19 of FIG. As shown in FIG. 6A, after the work 4 is adsorbed, the adsorber 6 is pulled up by the elevating means 14. Then, as shown in FIG. 6B, the suction surface of the work 4 follows the flat plate 8, and the posture of the work 4 after being pulled up is stabilized. When the adsorbent 6 of the lifting means approaches the work 4 as described above, since there is no object other than the adsorbent 6, even the work 4 having a complicated shape or the work 4 having a rib or the like on the surface is adsorbed. Raising becomes possible. Also, the work 4 is applied to the flat plate 8 to
In order to stabilize the posture, the contact area with the work 4 when stabilizing the posture is large, and the posture stability of the work 4 after being pulled up is high. Further, even if the suction surface of the work 4 has irregularities, the posture of the work 4 after being pulled up is stabilized.

Next, an example of the embodiment shown in FIG. 7 will be described. In this example, the following means was employed in the robot hand. After the suction element 6 of the lifting means approaches the work 4, air is blown against the work 4 with a smaller suction force of the suction pad 6 b of the suction means 6 so that the work 4 is pulled up while the posture of the work 4 is stabilized. Posture stabilizing means is provided. The adsorber 6 is a first elevating means 14a
The air blowing member 22, which is a means for blowing air to the work 4, is provided with a second lifting means 14b.
And the second elevating means 14b is installed on the first elevating means 14a. First, FIG.
As shown in (b), the first lifting means 14a is lowered to adsorb the work 4 to the adsorbent 6. Next, as shown in FIG. 7C, the second elevating means 14b is lowered, and the posture of the work 4 is stabilized by blowing air to the work 4. Next, the first lifting means 14a is raised, and the work 4 is lifted while the posture of the work 4 is stabilized as shown in FIG. 7D. By doing so, the posture of the work 4 can be stabilized without contacting the air, and there is no danger of damaging the work 4. When the adsorbent 6 approaches the work 4, there is no object other than the adsorbent 6, so that even the work 4 having a complicated shape or the work 4 having a rib or the like on its surface can be attracted and pulled up.

Next, an example of the embodiment shown in FIG. 8 will be described. In this example, the following means was employed in the robot hand. When approaching the suction element 6 of the lifting means to the work 4, a seat (contact) 16 as a posture stabilizing means is provided around the suction element 6, so that the work 4 is raised while the posture of the work 4 is stabilized. The adsorber 6 can be moved up and down by the first elevating means 14a, and the coil spring 17 wound around the rod 6a is moved by the second elevating means 14a.
b so as to be able to move up and down freely.
The lower end of the coil spring 17 is a seat 16. First, FIG.
As shown in (b), the first elevating means 14a is lowered,
The work 4 is adsorbed to the adsorber 6. Next, the second elevating means 1
4b is lowered and the seat 16 at the lower end of the coil spring 17 is brought into contact with the work 4 to stabilize the posture of the work 4. Next, the first lifting means 14a is raised, and the work 4 is lifted while the posture of the work 4 is stabilized. If a position away from the center of gravity of the work 4 is sucked, the work 4 may be lifted while being tilted and fall, but this can be avoided by using the above-described method. Further, the work 4 can be pulled up in a stable state without fluctuation.

Next, an example of the embodiment shown in FIG. 9 will be described. In this example, the following means was employed in the robot hand. When the attracting element 6 of the lifting means approaches the workpiece 4, a plurality of pins 18 as attitude stabilizing means are provided around the attracting element 6 so that the workpiece 4 is lifted while its attitude is stabilized. The adsorber 6 can be moved up and down by a first elevating means 14a, a plurality of pins 18 arranged so as to surround the rod 6a can be moved up and down by a second elevating means 14b, and the second elevating means 14b It is installed on the first elevating means 14a. First, FIG.
(A) As shown in (b), the first lifting / lowering means 14a is lowered to suck the work 4 onto the suction element 6. Next, FIG.
As shown in (2), the posture of the work 4 is stabilized by lowering the second lifting / lowering means 14b and applying the pin 18 to the work 4. Next, the first lifting means 14a is raised, and the work 4 is lifted while the posture of the work 4 is stabilized. At this time, the mounting position of the pin 18 can be adjusted according to the shape and size of the work 4. In this way, the position of the pin 18 for stabilizing the posture of the work 4 can be adjusted arbitrarily.
The position of the pin 18 in which the posture of the pin 18 is stabilized is possible. If the work 4 is sucked at a position distant from the center of gravity, the work 4 may be lifted while being tilted and fall, but this can be avoided.

Next, an example of the embodiment shown in FIG. 10 will be described. In this example, the following means was employed in the robot hand. The lifting of the adsorber 7 by the lifting means can be stopped in a stepwise manner. As shown in FIG. 10, a second elevating means 14b is installed on the first elevating means 14a, the adsorber 6 is attached to the second elevating means 14b, and the adsorbent 6 is connected to the first elevating means 14a and the second elevating means 14a. It can be moved up and down with the elevating means 14b. When both the first elevating means 14a and the second elevating means 14b are raised,
The suction element 6 is installed so that the suction pad 6b at the lower end of the flat plate 8 is aligned with the lower surface of the flat plate 8. When the suction pad 6b of the suction element 6 sucks the non-concave surface of the work 4 as shown in FIGS. 10 (a) and 10 (b), the first and second lifting means 14a and 14b are raised together, and the posture of the work 4 is changed. Stabilize. FIG. 10 (c)
When the suction pad 6b sucks the concave surface of the work 4 as shown in (d), only the first lifting / lowering means 14a is raised to stabilize the posture of the work 4. At this time, the suction pad 6b is adjusted so as to stop at a position below the lower surface of the flat plate 8 by the depth of the work 4. In this way, even if the shape of the work 4 has a concave surface like a channel, the posture can be stabilized by adjusting the lifting amount.

Next, an example of the embodiment shown in FIG. 11 will be described. In this example, the following structure was adopted in the robot hand. Lifting means for raising and lowering the gripping means of the work 4; the gripping means is positioned above the flat plate 8 until the work 4 is lifted to the position of the flat plate 8; Is lowered to grip the work 4. As shown in FIG. 11 (a), the work 4 is attracted to the attraction element 6, and the claw 5, which is a means for gripping the work 4, is raised above the flat plate 8 until the work 4 is pulled up and hit the flat plate 8. . After the work 4 is pulled up as shown in FIG. 11B and the posture is stabilized, FIG.
The work 4 is gripped by the claw 5 by lowering the claw 5 as shown in FIG. By doing so, the lifting stroke of the adsorber 6 can be increased. Further, it is possible to prevent the claws 5 serving as gripping means from interfering with the surrounding work 4 and damaging the work 4.

Next, an example of the embodiment shown in FIG. 12 will be described. In this example, the following structure was adopted in the robot hand. By arranging the flat plate 8 via an elastic body 20 such as a spring, compliance is provided in the lifting direction of the work 4. If an attempt is made to pick up the work 4 buried in the lower side of the work 4 stacked in bulk, there is a risk that the flat plate 8 will interfere with the surrounding work 4. FIG.
The part indicated by the symbol J is the part that interferes. However,
By attaching the hand main body 2a and the flat plate 8 via an elastic body 20 such as a spring as shown in FIG. 12, the flat plate 8 does not apply a load to the work 4 in the event that the above case occurs. It is configured to escape in the direction. In this way, even when the hand 2 approaches the hand 4 slightly due to the measurement error of the work 4 or when the surrounding work 4 is higher than the target work 4, the hand 2
And the risk of damaging the work 4 can be avoided.

[0033]

As described above, the present invention provides a suction means having a suction part for sucking a work at the tip of a tiltable rod, a lifting means having a drive part capable of moving the suction means up and down, and a work. Measuring means for measuring the position and orientation of the workpiece, stroke adjusting means for calculating and controlling the amount of lifting stroke for lifting the workpiece based on the information measured by the workpiece measuring means, and suppressing the vibration of the workpiece after suction to stabilize the attitude. The posture stabilizing means, the gripping means having a plurality of claws, and the angle difference absorbing means for absorbing the angle difference between the normal direction of the suction surface of the workpiece and the normal direction of the rod are provided on the hand body at the tip of the arm of the robot. I prepared
The work is sucked by the suction means and pulled up to a safe area where the work does not interfere with the surrounding work, the posture of the work is stabilized by the posture stabilizing means, and the work can be gripped by the gripping means. It is possible to carry out bin picking without damaging surrounding work because it is lifted to the safe area without direct gripping and then gripped, and the position and orientation of the work are measured by the work measuring means, and the work measuring means The amount of work to be lifted is calculated based on the information measured by the controller, and the amount of work to be lifted is adjusted.Therefore, the shape, position and orientation of the work to be lifted are not limited, and it is highly versatile. Since it has an angle difference absorbing means for absorbing the angle difference between the line direction and the normal direction of the rod, the container in which the workpieces are Also it can be performed pulled by suction from the vertical direction relative to the workpiece and greater inclined work in time, in which it is possible to pick all the work of the inner vessel.

[Brief description of the drawings]

FIG. 1A is a perspective view illustrating the structure and operation of a robot hand according to an embodiment of the present invention, FIG. 1B is a perspective view illustrating the specific structure of the robot hand, and FIG.
FIG. 4 is a cross-sectional view showing a structure of an adsorbent part.

FIG. 2 shows another example of the above, wherein (a) and (b) are front views,
(C) is a perspective view.

FIGS. 3A and 3B are perspective views showing another example of the above.

FIGS. 4A and 4B are front views showing another example of the above.

FIGS. 5A and 5B are front views showing another example of the above.

FIGS. 6A and 6B are front views showing another example of the above.

FIGS. 7 (a), (b), (c) and (d) are front views showing other examples of the above.

8 (a), (b), (c), and (d) are front views showing another example of the above.

FIGS. 9A, 9B, 9C, and 9D are front views showing other examples of the above.

10 (a), (b), (c) and (d) are front views showing other examples of the above.

11 (a), (b) and (c) are front views showing another example of the above.

FIG. 12 is a front view showing another example of the above.

FIG. 13 is an explanatory diagram illustrating a conventional example.

FIG. 14 is a perspective view showing a main part of a conventional example.

[Explanation of symbols]

 1 Arm 2 Hand 2a Hand body 3 Container 4 Work 5 Claw 6 Adsorber 6a Rod 6b Suction pad 8 Flat plate 11 Sensor 16 Seat 18 Pin

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C007 DS01 ES03 EV18 EW00 FS01 FT02 FT16 FT17 FU00 FU02 HS12 KS30 3F059 AA01 BA07 DA02 DB04 DC07 DD11 FC04 3F061 AA01 BA03 BD01 BE32 BF00 CA01 CB03 CB12 CB13 CC00 CC03

Claims (12)

[Claims] 1. A suction means having a suction portion for sucking a work at a tip of a tiltable rod, and raising and lowering the suction means.
Lifting and lowering means having a drive unit capable of lowering, work measuring means for measuring the position and orientation of the work, stroke adjusting means for calculating and controlling a lifting stroke amount for lifting the work based on information measured by the work measuring means; A posture stabilizing means for suppressing the vibration of the work after suction and stabilizing the posture, a gripping means having a plurality of claws, and an angle for absorbing an angle difference between a normal direction of the suction surface of the work and a normal direction of the rod. A bin picking robot hand comprising a difference absorbing means and a hand body at the tip of a robot arm. 2. When the inclination angle of the workpiece measured by the workpiece measuring means exceeds a preset threshold value, control is performed so that the workpiece approaches and is attracted while the inclination angle of the rod is fixed at the threshold value. The robot hand according to claim 1, further comprising a control unit. 3. The hand body approaches from the vertical direction regardless of the inclination of the work, moves the work body to the vicinity of the center of the container while sucking the work by the lifting means, regardless of the inclination of the work, and then re-enters the work. 3. The robot hand according to claim 1, further comprising control means for controlling a work pick-up operation to be restarted. 4. The apparatus according to claim 1, further comprising a detecting means for setting a closing width of the gripping means for gripping the work smaller than the work size and detecting a position where the closing limit is reached. The robot hand according to claim 1, further comprising a control unit configured to determine that the gripping has failed and restart the pickup operation again. 5. 5. A method according to claim 1, wherein the gripping means for gripping the workpiece has compliance so that the gripping surface follows the tapered surface even when the workpiece has a tapered surface. The robot hand according to any one of claims 1 to 4. 6. A flat plate is provided as a posture stabilizing means at a predetermined position, and when the work is attracted and pulled up by the lifting means, the work is pulled up to the position of the flat plate so as to stabilize the posture after the lifting by the flat plate. The robot hand according to claim 1, wherein: 7. A posture stabilization method in which after the suction means of the lifting means approaches the work, air is blown to the work with a smaller suction force of the suction means to lift the work while keeping the work posture stable. The robot hand according to any one of claims 1 to 5, further comprising means. 8. The method according to claim 8, wherein a seat is provided as a posture stabilizing means around the adsorber when the adsorber of the lifting means approaches the work, so that the work is pulled up while keeping its posture stable. The robot hand according to claim 1. 9. A method in which a plurality of pins serving as posture stabilizing means are provided around the adsorber when the adsorbent of the lifting means approaches the work, whereby the work is pulled up while keeping its posture stable. Claim 1
The robot hand according to claim 5. 10. The robot hand according to claim 6, wherein the lifting of the attraction element by the lifting means can be stopped in a stepwise manner. 11. A lifting means for lifting and lowering a gripping means of a work, wherein the gripping means is positioned above the flat plate until the work is raised to the flat plate position, and after the work is pulled up to the flat plate position, the gripping means is moved to the flat plate position. 7. The robot hand according to claim 6, wherein the workpiece is lowered to grip the workpiece. 12. The robot hand according to claim 6, wherein a flat plate is provided via an elastic body to provide compliance in a work lifting direction.