JP7227745B2 - Palletizing device - Google Patents

Description

The present invention relates to a palletizing apparatus and a palletizing method.

Palletizing and depalletizing by robots are widely used in industry. Techniques for palletizing and the like using robots are described, for example, in Patent Document 1 and Patent Document 2. The picking system described in Patent Literature 1 is configured such that a robot palletizes items on single-item pallets onto shipping pallets or places them on a conveyor. At this time, the article gripped by the gripping device of the hand of the robot passes through the label pasting section with its side facing, and the tag is pasted thereon. In the palletizing device coaching method described in Patent Document 2, parameters are set from a computer screen, and instructions are given to a robot to set or modify a palletizing pattern, set a palletizing order, and set a palletizing position.

By the way, as long as robots are used, facilities that perform palletizing operations require equipment with high safety. Although Patent Literature 1 and Patent Literature 2 described above do not describe a configuration for ensuring safety, they do describe installing a fence with a sufficient spatial margin around the robot. For the safety of workers, an automatic pallet loading/unloading device is also used to supply pallets to a robot where palletizing work is performed, or to remove pallets that have completed palletizing work from the robot's operating range. ing. The automatic transfer section is expensive, has complicated mechanisms and controls, and requires a sufficient range of movement.
In view of the above, a relatively wide area that includes the range in which the robots work is required in a facility where palletizing operations are performed with known safety measures.

JP-A-6-024428 JP-A-8-267382

However, at facilities where palletizing is carried out, there are many cases where it is not possible to secure a sufficient range for installing palletizing robots. is occurring. Furthermore, when it becomes necessary to manually correct the position, add, or remove palletized items due to an abnormality during the palletizing operation, the pallet must be moved to a safe location by the automatic transport unit. I had to.
The present invention has been made in view of the above points, and detects an object entering a robot passage space that is limited in advance to ensure safety even when a worker approaches the robot passage space. The present invention also relates to a palletizing apparatus and a palletizing method that can be made compact because the range to which entry is restricted is relatively small.

The palletizing apparatus of the present invention transports the articles between an entry/exit position where the articles are received from the conveying section or delivered to the conveying section, and a pallet position where the pallet on which the articles are stacked or unloaded is installed. A palletizing device that performs a palletizing operation of stacking the articles on the pallet or a depalletizing operation of unloading the articles from the pallet,
A robot, a robot control section for controlling the operation of the robot, and a boundary detection section connected to the robot control section, the boundary detection section being configured so that the robot passes through during the palletizing operation or the depalletizing operation. At least a part of a boundary between an entry-prohibited space containing a passable space and an external space defined outside the entry-prohibited space is defined as a detection area, an object passing through the detection area is detected, and the robot control unit detects an object passing through the detection area. stops the robot or reduces the moving speed of the robot when the boundary detection unit detects an object passing through the detection zone;

In the palletizing method of the present invention, the goods are transported between an entry/exit position at which goods are received from a conveying section or delivered to the conveying section, and a pallet position at which a pallet on which the goods are stacked or unloaded is installed. A palletizing method for performing a palletizing operation of stacking articles on a pallet or a depalletizing operation of unloading articles from the pallet, comprising: a restricted space including a passage space through which a robot can pass during the palletizing operation or the depalletizing operation; a boundary detection step of using at least a portion of a boundary with an external space defined outside the entry prohibited space as a detection area and detecting an object passing through the detection area; a robot control step that, when detected, stops the robot or reduces the speed of movement of the robot.

INDUSTRIAL APPLICABILITY According to the present invention, an object entering a robot passage range limited in advance can be detected, and safety can be ensured even when a worker approaches the robot passage range. It is possible to provide a palletizing apparatus and a palletizing method that are relatively small and can be made compact.

1 is a perspective view for explaining the outline of a palletizing device according to one embodiment of the present invention; FIG. 2 is a diagram for explaining a detection area corresponding to pallet P1 shown in FIG. 1; FIG. 2 is a diagram for explaining a detection area corresponding to pallet P2 shown in FIG. 1; FIG. 2 is a diagram for explaining detection areas where each sensor of the palletizing device shown in FIG. 1 detects an entering object; FIG. FIG. 4 is a diagram for explaining a robot control unit of the palletizing apparatus according to one embodiment of the present invention; 2 is a diagram for explaining the operation of the palletizing device shown in FIG. 1; FIG. FIG. 3 is a diagram for explaining a modification of the palletizing device shown in FIG. 1 and the like; FIG. 5 is a diagram for explaining another modification of the palletizing device shown in FIG. 1 and the like;

An embodiment of the present invention will be described below with reference to the drawings. In addition, in all the drawings, the same components are denoted by the same reference numerals, and overlapping descriptions are omitted as appropriate. Moreover, the drawings of the present embodiment are diagrams for explaining the configuration, functions and effects of the present invention, and do not necessarily represent the length, height, aspect ratio, etc. of the present invention accurately. Furthermore, the specific shape of this embodiment is not limited to the shape shown in the drawings.

[Overview]
First, prior to describing the embodiments of the present invention, the outline of the palletizing apparatus and palletizing method of the present invention will be described.
FIG. 1 is a perspective view for explaining the outline of the palletizing device 1. FIG. A palletizing apparatus 1 shown in FIG. 1 uses a robot 2 working in a predetermined space A. A plurality (two) of pallets P1 and P2 are installed in the space A, and the pallets P1 and P2 are installed at preset pallet positions pp1 and pp2. An article (work) W is carried into or out of the space A by a transport section C. As shown in FIG. The work W is an article to be palletized or depalletized by the robot 2 . The pallet positions pp1 and pp2 are areas on the floor (not shown) having a shape that substantially matches the shape of the pallets P1 and P2 when viewed from above.

Palletizing refers to an operation in which the robot 2 stacks the workpieces W transported by the transport unit C on the plate surface S of the pallet P1 or the pallet P2 (hereinafter referred to as "stacked plate surface"), and is the opposite of depalletizing. 2, the works W stacked on the pallets P1 and P2 are unloaded from the stacking plate surface S and moved to the transport section C. A space A shown in FIG. 1 is a working area where the robot 2 performs palletizing or depalletizing operations on the two pallets P1 and P2. It contains the space that is entered and the space that is allowed to enter.

The robot 2 operates within a restricted movable range. The "restricted movable range" in the present embodiment is a range in which the workpiece W gripped by the end effector 251 attached to the arm 25 of the robot 2 can move. means the range constrained to The restricted movable range includes the restricted range in which the end effector 251 attached to the arm 25 of the robot 2 can move. Safety measures are implemented by regarding the range of movement of the workpiece W as the "movable range".

In this embodiment, as a safety measure, the robot 2 is provided with sensors (boundary sensors 11, 12, etc.) that detect objects entering the movable range of the robot 2 or the surroundings of the movable range. The "entering object" as used herein may be any object that moves voluntarily or under the control or operation of another person, regardless of whether it is a living thing or an inanimate object. For example, a person such as a worker can be considered as an intruder of a living thing. In addition, as the inanimate object, for example, an automatic transport robot that carries the pallets P1 and P2 and the pallets P1 and P2 into and out of the pallet positions pp1 and pp2 can be considered.
According to the boundary sensors 11 and 12, it is possible to prevent the robot 2 from coming into contact with an intruding object, stopping the robot due to the contact, and reducing work efficiency. As other safety measures, for example, covering the arm 25 with a flexible material or providing a fence enclosing the movable range of the robot 2 can be considered.

Restrictions on the operating range include restrictions based on the program of the control device of the robot 2 and mechanical restrictions. Constraints by the program of the control device are such that the robot 2 can be controlled by others (including people and objects) in consideration of the shape and size of the robot 2, the size of the work W, the operation of palletizing and depalletizing, and the work environment prior to the start of work. ) to create a constrained range of motion that does not contact the
In the present invention, this restricted movable range is called a passage space of the robot 2. As shown in FIG. Here, monitoring is performed so that the robot 2 does not exceed its passage space. It monitors the speed, position, stop status, etc. in real time, and if it seems to exceed the passing space, it will be forced to stop. Conversely, the outside of the movable range may be set as the monitoring range, and the entry of the robot into this monitoring range may be monitored. If the program for the control device that monitors the robot 2 so that it does not exceed its passage space is created independently of the program for palletizing and depalletizing the robot 2, it may be affected by the program for palletizing and depalletizing. Therefore, reliability is improved and it is preferable. The program of the controller to be monitored is not particularly limited. Examples of commercially available products to be added to the robot controller include the Dual Check Safety (DCS) manufactured by Fanuc Corporation, the functional safety board DX200 manufactured by Yaskawa Electric, and the safety expansion unit manufactured by Mitsubishi Electric. Examples of robot controllers built in advance include the RC8A controller manufactured by Denso Wave Co., Ltd., and the robot CR-7iA, CR-4iA, CR-15iA, CR-7iA, and CR-35iA manufactured by Fanuc Corporation. be done. Among them, robots CR-7iA, CR-4iA, CR-15iA, CR-7iA, and CR-35iA manufactured by FANUC CORPORATION, which are collaborative robots conforming to ISO10218-1 (JIS B 8433-1), are particularly useful. Are suitable.
This embodiment uses software that is a highly reliable monitoring program that is independent of the main program that performs palletizing and depalletizing operations. It is more preferable to monitor the robot 2 so that it does not exceed its passing range by a combination of the robot 2 and software. In this way, even if the robot 2 moves unexpectedly due to an error in the operation program of the robot 2, any part of the robot 2 or the work W will not go out of the specified movable range. .

In order to realize the above configuration, it is preferable to monitor the speed and stoppage of the robot 2 by a control system that satisfies SIL2 or SIL3 (IEC 62061, IEC 61508) or PLd or Ple (ISO 13849-1).
Further, mechanical restrictions can be realized by installing a stopper that suppresses rotation on the rotating shaft closest to the base of the arm 25 of the robot 2 . Mechanical restrictions can reliably limit the movable range of the robot, apart from the program and control of the robot 2 . Furthermore, such mechanical restrictions can minimize the movable range of the robot 2, so it is possible to widen the safe range where people can approach the robot 2 or to reduce the size of the entire system. is possible.

The robot used in this embodiment is preferably a so-called "collaborative robot". Collaborative robots are robots that are applied to collaborative work. There are movements within the work space specific to the application.
Collaborative robots are roughly classified into three types. The first is that the maximum output of the driving source of the robot is 80 W or less. Robots of 80 W or less are not included in industrial robots under the Ordinance on Industrial Safety and Health, so they are not subject to various laws and regulations related to industrial robots, and safety measures based on risk assessment by users and system integrators are required. Operation becomes possible by implementing Second, it has a highly reliable controller that satisfies SIL2 or SIL3 (IEC 62061, IEC 61508), PLd or Ple (in ISO 13849-1), monitors the speed and stop state of the robot, and further It also has an additional safety device unique to the robot manufacturer. It is also a robot whose system including the robot has been certified by a third-party certification body. The third refers to robots with characteristics specially designed for collaborative operation that conforms to ISO 10218-1 (JIS B 8433-1).

Among the above collaborative robots, the first one is preferable as the robot used in the present embodiment because safety measures for robot peripheral devices during use are easy. The second method is preferable in that the safety of the robot is high and there are many kinds of robots that can be selected. The third generally includes the second requirement (however, ``the robot must be certified by a third-party certification body for the system including the robot''), and further requires highly reliable safety measures. This is most preferable because the safety of the robot is extremely high.

Further, since the robot of this embodiment performs a palletizing operation, it is essential to have a function called pick-and-place, which lifts or places articles. The type of robot is not particularly limited, and may be a parallel link robot or a serial link robot. However, in this embodiment, since the range of work is relatively wide, a serial link robot with a wide movable range is preferable. .
Serial link robots include vertical articulated robots and SCARA robots. Of these, vertical multi-joint robots with degrees of freedom of four to seven axes are well known, and are most suitable for the present embodiment, which has a relatively wide working range. Further, SCARA robots are capable of high-speed horizontal movement, and four-axis robots are well known. The operating range is also relatively wide, which is suitable for this embodiment.

[Palletizing device]
The palletizing apparatus 1 of this embodiment will be described below. 2 and 3 are diagrams of the palletizing apparatus shown in FIG. 1 as seen from above. Here, "upper" and "lower" have a relationship determined according to the direction of gravity, and the bottom surface is the floor on which the pallet is installed. FIG. 2 is a diagram for explaining the detection area corresponding to the pallet P1, and FIG. 3 is a diagram for explaining the detection area corresponding to the pallet P2. FIG. 4 is a diagram for explaining detection areas where each sensor of the palletizing apparatus 1 of the present embodiment detects an entering object.

The palletizing apparatus 1 shown in FIGS. 1 to 3 receives workpieces from an entry/exit position Cp to be delivered to the conveying section C, picks up the workpieces W from the end Ce of the conveying section, and stacks them on a pallet, or conveys the workpieces W from the pallet. A transfer section C where the work is unloaded at the end Ce of the section C and discharged from the loading/unloading position Cp; Between the pallet positions pp1 and pp2 where the pallets P1 and P2 to be unloaded are installed, the palletizing operation of stacking the goods W on the pallets P1 and P2 or the depalletizing operation of unloading the goods W from the pallets P1 and P2 (hereinafter referred to as It is a device that performs "palletizing operation, etc."). The palletizing apparatus 1 as described above includes a robot 2 , a robot control section 5 that controls the operation of the robot 2 , and a boundary sensor 11 that is a boundary detection section connected to the robot control section 5 . The boundary sensors 11 (12) detect entry prohibited spaces Ab1 and Ab2 respectively containing passage spaces At1 and At2 through which the robot 2 can pass during the palletizing operation, etc. At least part of the boundary between the spaces Ao1 and Ao2 is defined as a first detection area As11 and a second detection area As12. ). The robot control unit 5 stops the robot 2 or reduces the movement speed of the robot 2 when an intruding object is detected by the boundary sensor 11 (12).
In this embodiment, the case where the robot 2 performs the palletizing operation will be described, but an entering object can also be detected in the depalletizing operation in the same manner.

A circular range Sr1 indicated by broken lines in FIGS. 2 and 3 indicates a range that the arm 25 of the robot 2 can reach mechanically. A range Sr2 indicates a range within which the workpiece W being gripped by the end effector 251 can reach. Ranges Sr1 and Sr2 are ranges within which the end effector 251 or the workpiece W can reach when there are no program or mechanical restrictions of the control device, and can be called "unrestricted ranges". On the other hand, the passage spaces At1 and At2 are the restricted movable range of the arm 25 of the robot 2 and the workpiece W gripped by the arm 25. FIG. It can be said that the passing spaces At1 and At2 are unsafe spaces. In FIGS. 2 and 3, the passage spaces At1 and At2 are shaded, and the prohibited spaces Ab1 and Ab2 are shaded more sharply than the passage spaces At1 and At2. In the example shown in FIGS. 2 and 3, the end effector 251 attached to the arm 25 and the workpiece W cannot reach around the base 27 (FIG. 1) of the robot 2. ) are not included in the passing spaces At1 and At2.

In this embodiment, the robot 2 performs a palletizing operation on the pallet P1 at the pallet position pp1, and after a predetermined number of works W are loaded on the pallet P1 (palletizing is completed), the pallet position A palletizing operation is performed for pallet P2 in pp2. The robot 2 alternately repeats the palletizing operation for the pallets P1 and P2. FIG. 2 shows the passing space At1, the forbidden space Ab1, and the outer space Ao1 when the robot 2 palletizes the pallet P1, and FIG. A forbidden space Ab2 and an outer space Ao2 are shown.
As shown in FIGS. 2 and 3, fences F are formed on three sides around the area where the robot 2 performs the palletizing operation. , g2, respectively.
When the robot 2 palletizes the pallet P1, the hatched area shown in FIG. 2 becomes the passing space At1. Also, the range with rough diagonal lines that includes the passage space At1 is the prohibited entry space Ab1, and the range further outside the prohibited space Ab1 is the external space Ao1.

[work]
Among the above configurations, the work W may be, for example, a box containing a product or a box without contents. The works W to be stacked or unloaded may all have the same shape and size, or may have different shapes. As a method for stacking the workpieces W, block stacking, alternate stacking, pinhole stacking, and applications or combinations thereof may be used. The work W applied to the palletizing apparatus 1 is not particularly limited, but is often a corrugated cardboard box. Corrugated cardboard boxes are classified into A type, wrap round type, and the like. The material of the corrugated cardboard is not limited, and it may be made of paper, plastic, or the like. A cardboard box is sometimes called a packing case or a PC case, but this embodiment can palletize any of these case bodies. Furthermore, the work W of the present embodiment may be a box made of paper material other than cardboard or a resin plate, a resin-molded box, a foldable resin box, or a member having a rectangular parallelepiped shape. Any object can be used as long as it can be regularly stacked without being limited to these rectangular parallelepiped objects.

[palette]
The pallets P1 and P2 only need to have a plate portion on which the work W can be loaded, and the type thereof is not limited. Therefore, the pallets P1 and P2 may be flat pallets, box carts, sheet materials, or the like, or may be a wheeled platform capable of towing a loadable plate portion. Materials for the pallets P1 and P2 are not particularly limited, and for example, wooden, resin, or paper materials are used. The size of the pallets P1 and P2 may be any size that can be installed at the pallet positions pp1 and pp2, respectively. have.

Pallets P1 and P2 are carried in and out of pallet positions pp1 and pp2 from pallet supply ports g1 and g2, respectively. Although the method of loading and unloading the pallets P1 and P2 is not particularly limited, it is conceivable to use a forklift, a manual hand fork, an automatic transport robot, or the like.
The positioning of the pallet positions pp1, pp2 is performed by mechanical stoppers, for example. Specifically, for example, the positioning can be realized by installing "U"-shaped or "L"-shaped members as stoppers at the corners of the pallet positions pp1 and pp2. Palletizing control for the pallets P1 and P2 is performed based on the pallet positions pp1 and pp2. Further, in this embodiment, the pallets P1 and P2 may be installed without being positioned, and the pallets P1 and P2 may be detected by sensors. When the pallets P1 and P2 are detected by sensors, the robot 2 is controlled based on the detected positions of the pallets P1 and P2. In such a case, the work of carrying out and carrying in the pallets to the pallet positions pp1 and pp2 is facilitated.

It should be noted that the pallets P1 and P2 of the present embodiment do not need to be carried out by an automatic loading/unloading device, and can be manually carried out. This point is advantageous in making the palletizing apparatus 1 of the present embodiment low cost and compact.
Further, in the present embodiment, an automatic pallet loading/unloading device may be used, and when the automatic loading/unloading device is used, the need to consider the situation of the robot 2 is reduced. Fewer timing constraints.
The pallets P1 and P2 are not particularly limited in the unloading/carrying-in directions, but by determining the unloading/carrying-in directions, the pallets P1 and P2 can be reliably positioned by low-cost stoppers. In addition, since the orientation and position of the pallets P1 and P2 are fixed, the control of the robot 2 is facilitated, and the programming of the robot at the time of installation of equipment is facilitated.

[robot]
As shown in FIG. 1, the robot 2 includes a base 27 installed on a base 26, a rotating part 28 on the base 27 that rotates around a vertical rotation axis, and a horizontal axis that is fixed to the rotating part 28. It has arms 24, 25 that rotate about directional axes. With such a configuration, the robot 2 can stack the workpieces W picked up by the end effector 251 from the transport section C on any of the pallets P1 and P2 arranged at both ends of the robot 2 .
Here, the end effector 251 will be described. The end effector 251 of this embodiment is a member that functions as a hand that grips the workpiece W and is attached to the tip of the arm 25 .

The end effector 251 of the palletizing robot is often of a suction type. As the suction end effector 251, a vacuum suction end effector 251 is known, and the vacuum suction end effector 251 includes a plurality of vacuum pads and an elastic body such as a sponge. . The end effector 251 equipped with a plurality of vacuum pads is provided with a vacuum check valve (vacuum check valve) for each of the vacuum pads, so that even if a vacuum leak occurs in one of the plurality of vacuum pads, the other vacuum pads are not affected. Such an end effector 251 is preferable because it is inexpensive and has excellent durability. The material of the vacuum pad is not particularly limited, but if a highly durable material such as polyurethane is used, the replacement period can be lengthened. The form of the vacuum pad is not particularly limited, but if a bellows type (bellows type) is used, the ability to follow the inclination of the surface of the work W can be improved. Also, if a spring plunger (buffer) having resilience in the height direction is provided, it is possible to cope with changes in the height of the surface of the workpiece W.

Furthermore, if the end effector 251 is provided with a vibration prevention mechanism for the work W, the vibration of the work W can be suppressed when the arm 25 grips the work W and moves in the horizontal direction, and the work W can be prevented from falling. can be done. As a work vibration prevention mechanism, an elastic material that can be deformed in the height direction is attached between the end effector 251 and the vacuum pad, or a vibration prevention member is lightly pressed against the work W by an air cylinder when the work W is sucked. It can be realized by making

The end effector 251 using an elastic body is, for example, an elastic body such as a sponge through which air does not pass, provided with a plurality of holes, and each hole is provided with a vacuum suction part and a check valve for vacuum (vacuum check valve). . The elastic body is a vacuum pad, which also has the function of preventing workpiece vibration. The end effector 251 using an elastic body is particularly suitable for reducing the size of the end effector 251 in the height direction. In addition, the end effector 251 using an elastic body is also suitable because the elastic body itself acts as a work deflection preventing mechanism.
Furthermore, in this embodiment, the end effector 251 may be provided with a sensor for measuring the distance to the work W, and the movements of the arms 24 and 25 may be controlled according to changes in the height of the work W stacked.

The end effector 251 is not limited to a configuration for sucking the work W, and may be one that grasps the work W with an opening/closing mechanism, or suspends the work W with a hook-like jig. It is also possible to arbitrarily combine a configuration for holding, gripping by an opening/closing mechanism, hanging by a jig, and the like. If the workpiece W is made of metal, the end effector 251 may be one that uses magnetic force, such as an electromagnet. Furthermore, one end effector 251 may grip a plurality of works. In this embodiment, a plurality of end effectors 251 having different configurations may be prepared and exchanged according to the work W. FIG. Replacement may be performed manually or by an automatic changer (tool changer).

[passing space, restricted space, external space]
As shown in FIG. 2, when the robot 2 palletizes a pallet P1, a passage space At1, an entry prohibited space Ab1, and an external space Ao1 are set according to the pallet position pp1. The passage space At1 is a restricted movable range of the robot 2, and is a space through which the robot 2 and the workpiece W during palletizing can pass. The entry-prohibited space Ab1 is outside the passage space At1, and if a person were to be in this space, there is a high possibility of entering the unsafe passage space At1 by an action such as reaching out. The external space Ao1 is a space further outside the entry prohibited space Ab1. Therefore, the entry-prohibited space Ab1 and the passage space At1 are spaces into which a person is prohibited from entering while the robot 2 is in operation, and the external space Ao1 is a space in which a person cannot enter regardless of whether the robot 2 is in operation or not. is the allowed space.

Further, as shown in FIG. 3, when the robot 2 palletizes the pallet P2, a passage space At2, an entry prohibited space Ab2, and an external space Ao2 are set according to the pallet position pp2. The passage space At2 is a restricted movable range of the robot 2, and is a space through which the robot 2 can pass during palletizing. The entry-prohibited space Ab2 is a space outside the passage space At2 but likely to enter the passage space At2. The external space Ao2 is a space further outside the entry prohibited space Ab2. The entry-prohibited space Ab2 and the passage space At2 are spaces into which people are prohibited from entering while the robot 2 is in operation, and the external space Ao2 allows people to enter regardless of whether the robot 2 is in operation or not. It is a space where

[Boundary sensor]
As shown in FIG. 2, the boundary sensor 11 has a first detection area As11 defined between the prohibited space Ab1 and the external space Ao1 and extending in the vertical direction. As shown in FIG. 3, the boundary sensor 12 has a second detection area As12 defined between the prohibited space Ab2 and the external space Ao2 and extending in the vertical direction.
Here, the vertical direction is the direction perpendicular to the floor surface (not shown), and since it is a plane, it has a spread in the direction orthogonal to the vertical direction as well as in the vertical direction. Also, the first detection area As11 and the second detection area As12 refer to the ranges detected by the boundary sensors 11 and 12, and the "plane" referred to here is a virtual plane for defining the detection areas. The plane is not limited to a plane parallel to the sides of the pallets P1 and P2 as shown in FIGS. good.

In this embodiment, as shown in FIGS. 1 to 3, a plurality of pallet positions pp1 and pp2 are set, and passage spaces At1 and At2 and entry-prohibited spaces Ab1 and Ab2 are set according to each of the pallet positions pp1 and pp2. and external spaces Ao1 and Ao2 are set respectively. Then, the robot 2 performs a palletizing operation at the first pallet position (pallet position pp1), which is either one of the pallet positions pp1 and pp2, and at the second pallet position (pallet position pp2), which is the other one. The palletizing operation is alternately performed, and the pallet on the side not performing the palletizing operation is taken in and out. At this time, in this embodiment, the detection area by the boundary sensors 11 and 12 is alternately switched between the first detection area As11 corresponding to the pallet position pp1 and the second detection area As12 corresponding to the pallet position pp2. This embodiment includes a switch 50, which is a switching unit for switching between the first detection area As11 and the second detection area As12 (FIG. 5).

The changeover switch 50 is a manually operable switch, and can be configured to be operated by, for example, an operator carrying the pallet P1 to switch between the first detection area As11 and the second detection area As12. . At this time, for example, the changeover switch 50 may be a toggle switch, and the direction of the knob may determine which of the first detection area As11 and the second detection area As12 is to be effective, or may be a push switch. A configuration may be adopted in which the effective detection area is switched to the first detection area As11 or the second detection area As12.
It is also possible to configure so that both the first detection area As11 and the second detection area As12 are disabled by neutralizing the toggle switch or pressing the push switch for a long time. When both the first detection area As11 and the second detection area As12 are invalidated, it is preferable to configure the robot 2 to stop completely.

Further, in this embodiment, the boundary sensors 11 and 12 detect the side of the first detection area As11 and the second detection area As12 where the palletizing operation or depalletizing operation is being performed. In other words, in this embodiment, the boundary sensor 11 detects an entry from the external space Ao1 corresponding to the pallet position pp1 shown in FIG. Entry from the external space Ao2 to the entry prohibited space Ab2 is not detected. Conversely, in this embodiment, the boundary sensor 12 detects an entry from the external space Ao2 corresponding to the pallet position pp2 shown in FIG. does not detect entry from the external space Ao1 corresponding to . By doing so, the present embodiment detects an intruder approaching the robot 2 during palletizing operation, stops or decelerates the robot 2, prevents contact between the intruding object and the robot 2, or absorbs impact due to contact. can be mitigated. In addition, in a space where the robot 2 cannot come into contact with the robot 2, the entry of an intruding object is detected so that the worker can work.

With such a configuration, the palletizing apparatus 1 of the present embodiment prohibits the approach of the robot 2 in a space where an incoming object may come into contact with the robot 2. Therefore, the safety of workers working around the robot 2 is ensured. can be secured. In addition, the palletizing apparatus 1 of the present embodiment requires a relatively small area where entry is prohibited, and can secure a wide work area.

Although there are no particular restrictions on the specific configuration of the boundary sensors 11 and 12, it is preferable to use highly reliable equipment or detection methods. From this point of view, the boundary sensors 11 and 12 are, for example, safety light curtains or safety laser scanners. The safety light curtain combines a light-projecting unit and a light-receiving unit, and the light-receiving unit receives a plurality of parallel light beams emitted from the light-projecting unit. The light-projecting unit and the light-receiving unit are arranged so that parallel rays are accurately received. The absence of an object (entering object) blocking the space between the light-projecting unit and the light-receiving unit is detected when all the parallel light beams reach the light-receiving unit. On the other hand, if part or all of the light beam is blocked, there is a possibility that there is an object (entering object) that blocks the space between the light-projecting unit and the light-receiving unit.
In the safety light curtain, for example, the light-receiving side unit may have a mechanism for outputting a signal, and the detection or non-detection of an intruding object may be notified to the outside by turning on or off the signal. The robot 2 is controlled to stop or decelerate when an intruding object is detected. Such safety light curtains are preferred due to their low installation costs in relatively small detection zones.

The safety laser scanner irradiates an infrared laser with a low energy level (class 1) while changing the radiation direction by a constant angle. By doing so, the infrared laser light is irradiated to a fan-shaped range. A safety laser scanner is equipped with a laser light source and a light receiver, and detects an intruding object based on whether or not the reflected light of the laser light emitted from the light source is received by the light receiver, or the time it takes for the light to be received. . Such a safety laser scanner can arbitrarily set the detection area. That is, according to the safety laser scanner, it is possible to irradiate a laser without defining an irradiation range and detect an intruding object only when the laser beam reflected within the detection area is received.

In addition, with the safety laser scanner, it is also possible to set multiple detection areas in one device. In such a configuration, for example, a certain range separated by a predetermined distance from the distance of the robot that is a danger source is set as a warning area, and when an intruding object is detected in the warning area, a warning signal is output and the robot is decelerated. Let Alternatively, a range closer to the robot than the warning area may be defined as a protection area, and when an intruding object is detected in the protection area, a protection signal may be output to stop the robot. In such a system, a warning signal and a protection signal can be output from independent dedicated terminals, so high reliability can be obtained. Also, the safety laser scanner is not limited to setting a plurality of detection areas, and each of the plurality of safety laser scanners may output a dedicated signal for stopping or decelerating the robot.

By setting a plurality of detection zones in one safety laser scanner, the number of installed safety laser scanners can be reduced, thereby reducing the cost of the system. Further, if a safety laser scanner is provided for each of the plurality of detection zones, the control of the detection of entering objects is simplified, and the reliability of the system can be improved. In the field of space recognition using safety laser scanners and image information, two-dimensional detection of intruding objects is currently common, but in the future, it will be possible to detect intruding objects in three dimensions at low cost. is also expected to become possible.
In the configuration in which multiple beams are irradiated in parallel or the configuration in which a single beam is scanned, the axis of the beam is adjusted to prevent the palm or arm of a person from being detected due to the gap between the beams. It is preferable to set the interval within 40 mm.

Further, the entrance/exit sensors 31 and 32 and the space sensors 21 and 22 are arranged in combination so as to face each other. At this time, in this embodiment, by adjusting the installation height, horizontal position, or angle of installation of the entrance/exit sensors 31, 32 and the space sensors 21, 22, one of them can receive the optical signal of the other facing sensor. can be prevented and false positives can be prevented. In a safety laser scanner having a wide detection range of, for example, 270°, there are cases where a pair of combinations seemingly do not face each other but have a positional relationship in which the other optical signal is received.

Further, the boundary sensors 11 and 12 of this embodiment are not limited to detecting a plane extending in the vertical direction as described above. It may be one that detects an object entering the surface. Such boundary sensors include, for example, safety mats. The safety mat is composed of, for example, a mat in which a non-conductive compressible separating material is sandwiched between conductive plates, and a controller. The plate material is selected from a metal plate, a conductive rubber, an electrode plate, etc., and becomes conductive when pressure is applied. In the device using the safety mat, the safety mat is installed at the boundary between the external space Ao1 and the no-entry space Ab1, and electrical conduction occurs in the safety mat while the robot 2 is working in the passage space At1, thereby It is also possible to detect an object entering the entry prohibited space Ab1 from .
Furthermore, in the present embodiment, a two-dimensional or three-dimensional image may be created by photographing the boundary between the external space Ao1 and the no-entry space Ab1, and an intruding object may be detected from this image.

Further, in this embodiment, the distances d1, d2, d3, and d4 between the boundary sensors 11 and 12 such as light curtains and safety laser scanners and the passing spaces At1 and At2 are determined based on the standards defined in JIS B 9715. there is Here, the values of the distances d1 to d4 are specifically considered.
Assuming that the first detection area As11 and the second detection area As12 are planes extending in the vertical direction like the boundary sensors 11 and 12, in an active photoelectric protection device with a detection capability of 40 mm or less, the time from detection to robot stop is That is, when the sum of response time and stop time is T (seconds), the minimum distance S (mm) from the detection zone to the danger zone must not be less than the value calculated using equation (1). That is, the minimum distance S (mm) is the minimum distance at which the hazard can stop before the hazard and the person come into contact with each other when the person approaches the moving hazard.
S=(K×T)+C (1)
In formula (1), K=2000 mm/sec, C=8(d-14), provided that even if d is less than 14 mm, it must not be less than 0 mm. d is the detection capability (mm) of the protection device.

From the above, the following formula (2) is established.
S=2000T+8(d-14) (2)
Equation (2) above applies for all minimum distances S less than or equal to 500 mm. The minimum value of S must be 100mm. Also, when S calculated by equation (2) exceeds 500 mm, equation (3) is applied. In this case the minimum value of S must be 500 mm.
S=(K×T)+C (3)
Here, K=1600 mm/s and C=8(d-14). However, even if d (detection capability (mm) of protective device) is less than 14 mm, C must not be less than 0 mm.
From the above, the following formula (4) holds.
S=1600T+8(d-14) (4)

Here, assuming that the stop time of the robot is 0.1 sec and the response time of a safety device such as an optical sensor with a minimum detection capability of 40 mm is 0.06 sec, the minimum distance S is calculated as follows.
S = 2000 x (0.1 + 0.06) + 8 (40 - 14) = 528mm
Since S exceeds 500 mm, applying equation (3) gives
S = 1600 x (0.1 + 0.06) + 8 (40 - 14) = 464mm
Since the minimum value of S must be 500 mm, the minimum distance S is 500 mm.
The direction of the first detection area As11 of the boundary sensor 11 and the direction of the second detection area As12 of the boundary sensor 12 is basically 90° perpendicular to the floor surface, but it may be slightly inclined depending on the surrounding conditions. good too.

[Space sensor]
Further, as shown in FIGS. 1 to 3, the palletizing apparatus 1 of the present embodiment performs processing (detection processing) for detecting objects in each of the passage space At1 corresponding to the pallet position pp1 and the passage space At2 corresponding to the pallet position pp2. processing), which are space sensors 21 and 22, which are space detection units. Then, the changeover switch 50 switches between the first detection area As11 and the second detection area As12 on condition that the object is not detected by the detection processing of the space sensors 21 and 22 .
The above control is performed to detect whether or not there is a person at the pallet positions pp1 and pp2 prior to switching between the first detection area As11 and the second detection area As12. With this configuration, in this embodiment, before the space sensors 21 and 22 start operating, processing is executed to detect objects already (remaining) at the pallet positions pp1 and pp2. After confirming that there is nothing at the positions pp1 and pp2, the operation of the robot 2 can be started.

Furthermore, this embodiment provides other detection areas in the space A besides the first detection area As11 and the second detection area As12. In addition to the space sensors 21 and 22 of the boundary sensors 11 and 12 described above, FIG. A fifth detection area As4 of the transport circumference sensor 4 is shown.
In the present embodiment, the space sensors 21 and 22 detect planes above the stacking plate surface S on which the pallet articles are stacked and intersecting the vertical direction as the third detection area As21 and the fourth detection area As22, respectively. and
By setting the third detection area As21 and the fourth detection area As22 at positions higher than the stacked board surface S, this embodiment detects the pallets P1 and P2 placed at the pallet positions pp1 and pp2 as incoming objects. Moreover, it is possible to reliably detect a residue such as a person, which is considered to exist in a place higher than the surface S of the stacked plates. Further, by forming the third detection area As21 and the fourth detection area As22 as planes intersecting the vertical direction, in this embodiment, it becomes easier to detect the entire range of the pallet positions pp1 and pp2.

Furthermore, this embodiment is not limited to setting the detection area as shown in FIG. For example, in this embodiment, in addition to the third detection area As21 and the fourth detection area As22, the third detection area As21 and the fourth detection area As22 may be part of or part of the third detection area including an additional area ( L) As21L (not shown) and a fourth detection zone (L) As22L (not shown) may additionally be set. When configured in this way, in this embodiment, the third detection area As21 and the third detection area (L) As21L are distinguished by the space sensor 21, and the fourth detection area As22 and the fourth detection area (L) As22L are separated from each other by the space sensor 21. The sensor 22 discriminates and detects. With such a configuration, the number of spatial sensors can be minimized. In addition, if all such sensors are independent space sensors, it is possible to further improve reliability in terms of safety. The third detection area (L) As21L and the fourth detection area (L) As22L are, for example, above the pallets P1 and P2 and exclude the area overlapping the stacked board surface S of the pallets P1 and P2 from the detection range. The range excludes the range, or the range that is wider than the overlapping range. Such a third detection area (L) As21L and a fourth detection area (L) As22L define a non-detection range based on a range overlapping with the rectangular stacked plate surface S. "" shape, "U" shape, or "square" shape.
With the above configuration, even if the pallets P1 and P2 are loaded with the works W, the present embodiment can detect workers around the pallets P1 and P2 by distinguishing them from the loaded works W. is possible. In this case, it is preferable that the space sensors 21 and 22 are installed in the vicinity of the pallet supply ports g1 and g2 and as far away from the robot 2 as possible.

[Transport sensor]
Further, as shown in FIGS. 3 and 4, the palletizing apparatus 1 of the present embodiment uses a range within the passage space At2 and including the vicinity of the entrance/exit position Cp as a fifth detection area As4. It is further provided with a conveying circumference sensor 4 which is a part. The entering/exiting position Cp in the present embodiment may be a position within the reach of the arm 25 of the robot 2 during transfer by the transfer section C. FIG. The transport sensor 4 can detect that a worker working around the transport section C enters the passage space At1. Furthermore, when the space sensors 21 and 22 are installed around the pallet supply ports g1 and g2 of the pallets P1 and P2, the work W stacked on the pallet may cause a blind spot around the transport section C. The sensor 4 can also detect an object entering the blind spot. Further, the sensor 4 around the transport can also detect an object entering the dead angle of the boundary sensors 11 and 12 by the transport unit C. FIG. A fifth detection area As4 is defined as a plane horizontal to the floor.
Further, when an intruding object is detected by the sensor 4 around the conveyance, for example, when a worker is present in the fifth detection area As4, when the robot picks up the work W, the worker is placed between the end effector 251 and the work W. Therefore, in this embodiment, the robot 2 is stopped or decelerated as in the case where the boundary sensors 11 and 12 detect an intruding object.

[Entrance detection sensor]
Furthermore, as shown in FIGS. 2 and 3, the palletizing apparatus 1 of the present embodiment has an area through which the pallet P1 is carried in from the outside to the pallet position pp1 or carried out from the pallet position pp1 to the outside. An entrance/exit sensor 31, which is an entrance/exit detector, is further provided as a sixth detection area As31. Further, as shown in FIGS. 2 and 3, the palletizing apparatus 1 detects a seventh detection area, which is an area through which the pallet P2 passes when it is carried in from the outside to the pallet position pp2 or carried out from the pallet position pp2 to the outside. An entrance/exit sensor 32, which is an entrance/exit detector, is further provided. The entrance/exit sensors 31 and 32 detect that an object approaches the robot 2 through the pallet supply ports g1 and g2 of the pallets P1 and P2. This embodiment stops or decelerates the robot 2 when the entrance sensor 31 or the entrance sensor 32 detects an entering object on the side of the prohibited entry space Ab1 or Ab2 where the robot 2 is performing the palletizing operation. I'm trying As a result, in this embodiment, the worker can safely carry out operations such as taking in and out the pallets P1 and P2 and repairing the workpiece W in the restricted entry space Ab1 or the restricted entry space Ab2 on the side where palletizing is not performed. can.

[fence]
As shown in FIGS. 2 and 3, the palletizing apparatus 1 further includes a fence F provided outside the entry-prohibited space. In this embodiment, the fence F is not formed at a position overlapping with the sixth detection area As31 and the seventh detection area As32, and entrance/exit sensors 31 and 32 monitor objects entering from the pallet supply openings g1 and g2. However, the present embodiment is not limited to such a configuration, and fences F are placed inside or outside the sixth detection area As31 and the seventh detection area As32 so as to be adjacent to or overlap the edges thereof. may be formed. In this way, when the fence F is opened during operation of the robot 2, the entrance/exit sensors 31 and 32 can monitor objects entering the pallet supply ports g1 and g2.

This embodiment does not particularly limit the fence F. The fence F may be, for example, a metal cage-like one, one using a metal net, one supporting an aluminum plate or transparent resin with an aluminum frame, or the like. The fence F is provided at a sufficiently safe distance from the passage spaces At1 and At2, and has a height sufficient to prevent human hands from reaching the passage spaces At1 and At2 from the outside. In addition, when the fence F is shaped like a cage or a wire mesh, it is required that the size of the gap is such that a human hand cannot pass through the gap. It is preferable that the standards for such a fence F be determined according to the provisions of JIS B 9716.

[Robot control unit]
FIG. 5 is a diagram for explaining the robot control unit 5 of the palletizing apparatus 1 of this embodiment. The robot control unit 5 of the palletizing apparatus 1 is executed on an operation panel 51, a PLC (Programmable Logic Controller) 52, a robot controller 55, a safety controller 56, and these hardware to control the robot 2 to stop or decelerate. Contains the program.
The operation panel 51 has switches and a touch panel for an operator to send instructions to the entire system including the palletizing apparatus 1, and meters for monitoring the magnitude of current and voltage applied to the system. A signal i1 representing instructions to start operation, stop operation, change operating conditions, etc. is sent from the operation panel 51 to the PLC 52, and a signal i3 representing instructions to start operation, stop operation, change operating conditions, etc. is sent from the PLC 52 to the robot controller. sent out. Also, the PLC 52 sends out a signal i10 to the transport section C via the relay circuit 53 in response to the signal i1 sent from the operation panel 51 . In response to the signal i10, the transport section C repeats stopping, moving, storing the work W, and the like. Such a PLC 52 can be realized by a small computer.

The robot controller 55 operates the robot 2 according to the passage spaces At1 and At2 and the no-entry spaces Ab1 and Ab2 defined by the safety controller 56 for control. In this embodiment, the robot controller 55 also stops the robot 2 and decelerates the rotational speed of the rotating portion 28 and the speed at which the arm 25 moves through the passage spaces At1 and At2. The safety controller 56 can be programmable, also called a safety PLC, or non-programmable, also called a safety relay unit. Both can be applied as the safety controller 56 of the present embodiment, but it is preferable to use the safety relay unit because higher reliability can be obtained. In the case of the palletizing method in which the robot 2 performs a palletizing operation or a depalletizing operation between the pallet positions pp1 and pp2, as shown in this embodiment, it is easy to switch between the two operations. It is preferable to use

A signal i8 output from the boundary sensors 11 and 12, the space sensors 21 and 22, the entrance/exit sensors 31 and 32, and the transport circumference sensor 4 is input to the safety controller 56. FIG. The safety controller 56 generates a signal i5 based on the input signal i8 and sends it to the robot controller 55 to instruct the robot 2 to stop or decelerate. In the present embodiment, entry into the restricted space on the side where the robot 2 is performing palletizing operations, etc. is detected. , each detection area is always detected regardless of whether or not the palletizing operation is being performed. However, the safety controller 56 does not use the signal i8 detected on the side where the palletizing operation is not performed as an unnecessary signal for controlling the robot 2 . Hereinafter, such control is also referred to as "not using a signal", and using the signal i8 for control is also referred to as "using a signal".

The changeover switch 50 of the present embodiment is a switch for the operator to manually switch between the passage spaces At1 and At2 in which the palletizing operation is performed. The changeover switch 50 is provided in a safe place and at a position where the pallets P1 and P2 can be seen. The type of the changeover switch 50 is not particularly limited, and it may be performed mechanically or by screen operation. The operator uses the selector switch 50 to specify the passing space At1 or the passing space At2 on the side where the robot 2 performs the palletizing operation. Although such a configuration requires an operator to operate the changeover switch 50, it has the advantages of simple control and high safety. In such a configuration, the passing space At1 or the passing space At2 being selected is visually indicated on a screen such as an indicator lamp or a liquid crystal display, so that an operator or the like may approach the robot 2 carelessly, It is preferable because the frequency of stopping or decelerating 2 can be minimized.

A signal i9 indicating the passage space in which the palletizing operation is performed is output from the changeover switch 50 to the safety controller 56 . When the safety controller 56 receives a signal i8 from any one of the boundary sensors 11 and 12, the space sensors 21 and 22, the entrance/exit sensors 31 and 32, and the transport circumference sensor 4 on the side where the palletizing operation and the like are being performed by i9, , outputs a signal i5 to the robot controller 55 . The robot controller 55 outputs a signal i6 for stopping or decelerating the robot 2 according to the signal i5. Furthermore, as an emergency measure, if the robot 2 is provided with an acceleration/deceleration sensor (not shown) for collision detection, a signal i7 indicating the acceleration or deceleration applied to the robot 2 is output from the acceleration/deceleration sensor to the robot controller 55. However, when there is a difference from the expected value, it is assumed that the robot 2 has collided with a person or object, and the robot 2 can be decelerated or stopped to operate safely. In addition, the robot controller 55 is provided with a system for detecting fluctuations in instantaneous torque, effective torque, current value, etc. of the servo motors of the robot 2, and when there is a difference from the expected value, the robot will collide with a person or object. , the robot 2 can be safely operated by decelerating or stopping the robot 2 .

Furthermore, the robot controller 55 outputs a signal i4 to notify the PLC 52 that the robot 2 has stopped or decelerated. The PLC 52 sends a signal i10 to the transport section C via the relay circuit 53, and stops or reduces the supply speed of the work W when the robot 2 stops or decelerates. In addition, the PLC 52 also transmits a signal i2 to the operation panel 51, and notifies the operator to the operation panel 51 that the robot 2 has stopped. The operator can be notified by buzzer, lamp lighting, and text display on a touch panel or the like.

However, this embodiment is not limited to such a configuration. For example, the robot controller 55 detects the start or completion of the palletizing operation, and automatically alternates between the passage spaces At1 and At2 in which the palletizing operation is performed. You may make it switch. Automatic switching is performed at the timing when the arm 25 is in the common space of the passage spaces At1 and At2 after the completion of the palletizing operation in the passage space At1 or At2. The common space is, for example, a position where the arm 25 takes up (picks) the work W at the entry/exit position Cp. At this time, the safety controller 56 uses the signal i8 input from the space sensor 21 or the space sensor 22 whose detection area is the side on which the next palletizing operation is performed to detect the pallet positions pp1 and pp2. Determine the presence or absence of residue. If it is determined that there is residue, there is a possibility that a person is at the pallet position. The board 51 is notified that the switching has been stopped.

This embodiment does not particularly limit the control to be performed thereafter. The passing space in which the palletizing operation is performed may be automatically switched. In order to further improve the safety of switching, after stopping the switching, the robot 2 is stopped normally or in an emergency, and using the operation panel 51, the operation start button is pressed for normal stop, and the reset button is pressed for emergency stop. After that, press the operation start button. With such an operation, in this embodiment, it is possible to understand the timing at which pallet work is possible simply by looking at the work status of the robot without performing a special switch operation.

Furthermore, in this embodiment, the robot control unit 5 uses at least part of the above hardware to perform control different from the above operation (stopping the robot or reducing the moving speed of the robot). may be operated. As another program, for example, at least a part of the robot 2 and the work W gripped by the end effector 251 of the robot 2 do not move out of the passage spaces At1 and At2 during the palletizing operation or the depalletizing operation. It may be a monitoring program that monitors. In this case, the monitoring program constitutes monitoring control means together with at least part of the safety PLC, robot controller 55 and safety controller 56 described above.
Another program may be, for example, a palletizing program that controls palletizing or depalletizing operations of the robot. The palletizing program constitutes palletizing control means together with at least part of the hardware. The palletizing control means and the monitoring control means are realized by independent programs and control the robot 2 .
Here, "each independent program" means that the processing of one of the two programs does not include at least a part of the processing of the other, and the results obtained by one program are used by the other program. may be
By doing so, in this embodiment, the process of monitoring the robot 2 so that it does not go out of the passage spaces At1 and At2 and the palletizing operation are not affected by each other. The movable range of the robot 2 can be monitored.

[Conveyor]
This embodiment does not particularly limit the conveying unit C. As shown in FIG. In the case of the conveyor which is the transport section C, it is preferable to use a roller conveyor with a slip function for this conveyor in order to minimize damage to the bottom of the work W on the conveyor. According to the roller conveyor, even if the preceding work W stops, the roller itself slips on its axis to stop the rotation, so that the bottom of the work W can be prevented from being damaged. The roller conveyor may use a motor roller that rotates a plurality of rollers by transmitting a driving force from one driving device with a belt, or rotates itself. Also, the conveyor may be a belt conveyor. In the case of a belt conveyor, it is possible to prevent the work W from slipping on the belt surface and damaging the bottom of the work W by installing sensors for detecting the work W at various locations and controlling the belt conveyor.

It is preferable that the workpieces W are transferred one by one to the end Ce of the transfer section where they are taken out by the end effector 251 of the arm 25 . In this way, when the robot 2 picks up the work W, the work W succeeding the work W to be taken out may be damaged, or the subsequent work W may apply force to the work W to be taken out, making it difficult to take out. You can prevent failure. Although the method of taking out the works W one by one is not particularly limited, for example, a plurality of works W are stopped using a stopper, and the work immediately after the work W to be taken out is stopped by another stopper. Then, it is conceivable to take out only one workpiece W to be taken out. Also, it is conceivable to use a stopper to stop a plurality of works W and take out only one of the stopped works W at a speed higher than that of the conveying section C. Furthermore, as described above, it is conceivable to use a plurality of belt conveyors and to operate the conveyor corresponding to the take-out position of the work W at a slightly higher speed.
Further, the supply of the works W to the transport section C may be performed by arranging a plurality of works W on a transport pallet or the like.

At the workpiece pick-up position in the transport section C, the workpiece W can be accurately picked up by the robot by accurately positioning the front, rear, right, and left positions of the workpiece W at preset positions and stopping the workpiece. A specific method is not particularly limited, but regarding the front-rear position, the front end of the work W may be stopped by a stopper. The left and right positions may be regulated during transportation by guides provided on the left and right sides, or a guide may be provided on one side at the take-out position, and the position may be determined by pushing the work W from the opposite side. Moreover, even if the position is inaccurate, the take-out position of the robot 2 may be corrected based on information captured by an optical sensor or an image processing device.
Also, in order to be able to handle various types of workpieces W, it is preferable to make the workpiece positioning mechanism easily adjustable. preferably. By using the image processing device, it becomes possible to register and change the images of various works, and it becomes possible to easily deal with a plurality of types of works W having different shapes.

[Palletizing method]
Next, a palletizing method using the palletizing apparatus 1 configured as described above will be described. The palletizing method of this embodiment includes an entry/exit position Cp at which the work W is received from or delivered to the transport section C; pp2 and in which the robot 2 performs a palletizing operation or a depalletizing operation within a restricted movable range. This palletizing method consists of prohibited spaces Ab1 and Ab2 containing passage spaces At1 and At2 through which the robot 2 can pass during palletizing or depalletizing operations, an external space Ao1 defined outside the prohibited spaces Ab1 and Ab2, At least a part of the boundary with Ao2 is defined as a first detection area As11 and a second detection area As12. and a robot control process for stopping the robot 2 or reducing the movement speed of the robot 2 when the entering object is detected by the boundary detection process.

Further, in the palletizing method of the present embodiment, there are a plurality (two) of pallet positions pp1 and pp2, and the robot 2 alternately performs palletizing or depalletizing operations at at least two of the plurality of pallet positions. . The boundary detection process is performed in a detection area set according to the pallets undergoing palletizing or depalletizing operations.

The above palletizing operation will be described in detail below with reference to FIG. FIG. 6 is a diagram showing the state of the changeover switch 50, the motion of the robot 2, the use/non-use of the boundary sensors 11 and 12 and the entrance/exit sensors 31 and 32, and the motion of the operator in association with each other. The palletizing operation described here includes four patterns from pattern (a) to pattern (d). In FIG. 6, the forbidden space Ab1 including the pallet position pp1 shown on the right side in FIGS. ”. "Boundary" indicates a boundary sensor, "entrance" indicates an entrance sensor, and "space" indicates a space sensor. The numbers 1 and 2 in parentheses following the characters of boundary, entrance, and space indicate area 1 and area 2, respectively. Boundary (1) indicates the boundary sensor 11 of area 1 and boundary (2) indicates the boundary sensor 12 of area 2. FIG. Also, space (1) indicates the space sensor 21 for area 1, space (2) indicates the space sensor 22 for area 2, doorway (1) indicates the doorway sensor 31 for area 1, and doorway (2) is the area 2 doorway sensors 32 are shown.

In pattern (a), first, the switch 50 is replaced in area 2 and stacked in area 1 . In such a case, in the palletizing method of the present embodiment, the pallet P2 on which the works W have been stacked is extracted and the works W are put on the pallet position pp2, which is the pallet position where the palletizing operation or depalletizing operation is not performed. It further includes a step of loading the pallet P2 which has not been loaded. The step of carrying in the pallet P2 may be performed by an operator, or may be performed automatically by an automatic pallet loading/unloading device.

While the pallet P2 is being replaced in the area 2, the robot 2 stacks the works W on the pallet P1 in the area 1.例文帳に追加Robot 2 normally stops automatically when stacking is completed in area 1 . At this time, the safety controller 56 uses the signal of the entrance (1) that detects entry into area 1, that is, the entrance (2) that detects entry into area 2, out of the entrance sensors 31 and 32, that is, the signal from the entrance sensor 31. ), that is, the signal of the entrance/exit sensor 32 is not used. The signal from the entrance/exit sensor 32 intermittently detects incoming objects for the work of replacing the pallet P2 through the pallet supply port g2. Even if there is a worker at the pallet supply port g2, this position is far enough to avoid contact with the robot 2. Therefore, in this embodiment, the robot 2 can be operated without deceleration, and work efficiency can be maintained.
In addition, the safety controller 56 uses the boundary (1) that detects entry into area 1, that is, the signal of boundary sensor 11, and the boundary (2) that detects entry into area 2, that is, the signal of boundary sensor 12. do not use. The signal from the boundary sensor 12 is intermittently detecting an intruding object due to the operator's motion in the area 2 .

When the boundary sensor 11 detects an intruding object, there is a possibility that a person has approached the robot 2 in motion. Therefore, the safety controller 56 outputs a signal i5 to the robot controller 55 to instruct the robot 2 to stop or decelerate. At this time, it is preferable to stop the robot 2 in order to reliably prevent a person from contacting the robot 2 . Also, if the entrance/exit sensor 31 detects an entering object during the palletizing operation in the area 1, there is a possibility that a person has approached the area 2 through the pallet supply port g1. Therefore, the safety controller 56 outputs i5 to the robot controller 55 to instruct the area 2 to stop or decelerate.

When the operator finishes the work of replacing the pallet P2 in area 2, the palletizing operation shifts from pattern (a) to pattern (b) in FIG. In pattern (b), the operator switches the changeover switch 50 to stacking in both area 2 and area 1 . When the stacking of works has been completed in area 1 at the time of switching, or when the stacking of works has been completed in area 1 after switching, the safety controller 56 determines whether the space sensor 22 in area 2 has detected residual matter. If detected, the control is not switched from the monitoring of the area 2 to the monitoring of the area 1, and the operation panel 51 side is notified, for example. This indicates the possibility that there is a worker in area 2, and robot 2 that has completed stacking the workpieces in area 1 is stopped.
If no residue is detected, robot 2 begins stacking in area 2 . The safety controller 56 uses the signals of the entrance/exit sensors 31 and 32 and does not use the signals of the boundary sensors 11 and 12 . That is, when the changeover switch 50 is stacked in both the area 2 and the area 1, it is detected that an intruding object enters both the prohibited spaces Ab1 and Ab2, and the robot 2 itself that is stacking is detected. This is to prevent the robot 2 from stopping or decelerating.

Next, in pattern (c), in order to carry out pallet P1 in area 1, the operator switches the selector switch 50 on the side of area 1 to exchange. The robot 2 normally stops when the stacking in the area 2 is completed. During stacking in area 2, the safety controller 56 uses the signal of the entrance/exit sensor 32 and does not use the signal of the entrance/exit sensor 31 . Also, the signal from the boundary sensor 11 is not used, but the signal from the boundary sensor 12 is used.

Next, in pattern (d), when the operator completes the work of exchanging the pallet P1 in area 1, the changeover switch 50 is switched to stacking in both area 2 and area 1. FIG. When the stacking of works has been completed in area 2 at the time of switching, or when the stacking of works has been completed in area 2 after switching, the safety controller 56 determines whether the space sensor 21 in area 1 has detected residual matter. determine whether or not As a result of the determination, when a residue is detected, the control is not switched from the monitoring of the area 1 to the monitoring of the area 2, and the operation panel 51 side is notified. This indicates the possibility that there is a worker in area 1, and robot 2 that has completed stacking the workpieces in area 2 stops. If no residue is detected, robot 2 begins stacking in area 1 . The safety controller 56 uses the signals of the entrance/exit sensors 31 and 32 and does not use the signals of the boundary sensors 11 and 12 . In other words, when the changeover switch 50 is for stacking in both area 2 and area 1, it detects that an intruding object is entering both the prohibited spaces Ab1 and Ab2, and also detects the robot 2 itself that is stacking up. This is to prevent the vehicle from stopping or decelerating.

After the above processing, the palletizing operation returns to pattern (a), and the operator switches the selector switch 50 on the area 2 side to exchange to exchange the pallet P2 in the area 2. FIG.
After the stacking is completed, the operator switches the changeover switch 50 to the stacking in both area 2 and area 1. - 特許庁The safety controller 56 determines whether or not there is residue in area 1 from the signal from the space sensor 21, and switches control from monitoring area 2 to monitoring area 1 if no residue is detected. After that, stacking and exchanging operations are repeated in the same manner in areas 1 and 2 .

Also, in a pattern (not shown) where the switch 50 on the area 1 side is replaced and the switch 50 on the area 2 side is replaced (not shown), if the robot 2 is in either area 1 or area 2, When the robot is detected at boundary (2) (second detection area As12) or boundary (1) (first detection area As11), robot 2 stops or decelerates. If the robot 2 is stopped, it may not be possible to restart it unless the changeover switch 50 on the side where the robot 2 is located is stacked. In this case, it is advisable to take measures such as instructing the operation panel 51 to switch the selector switch 50 on the side where the robot 2 is located to stacking. In addition, since stopping or decelerating reduces productivity, an instruction may be given not to replace both of them during operation.

In order to further improve safety, when changing the changeover switch 50 from replacement to stacking, if control is performed so that stacking does not start until a confirmation button such as reset is pressed after changing to stacking, safety confirmation can be performed reliably. will be

Moreover, this embodiment is not limited to the above configuration. For example, the present embodiment is not limited to ignoring the detection when an entering object is detected in a prohibited space in which no palletizing operation is being performed. For example, in this embodiment, when an entering object is detected in a prohibited space where no palletizing operation is performed, the robot may be decelerated at a safe speed. Here, the safe speed is preferably set to 250 mm/sec (robot arm tip speed) or less, which is the safe reduced speed specified in ISO10218-1 (JIS B 8433-1).

As described above, in the present embodiment, entry into the restricted area is prohibited according to the minimum range through which the robot 2 can pass. can be detected to ensure safety even if the worker approaches the space through which the robot passes. In addition, this embodiment does not interfere with the work in the outside space by enabling switching of the prohibited space, which is a restricted movable range, and detects objects approaching the robot in the prohibited space. work safety. Note that pallet work is a major work in the external space. Pallet work includes the supply of empty pallets by hand truck or forklift, the unloading of pallets that have been loaded with works, the manual correction of the position of works on the pallet, the addition of insufficient works, the removal of surplus works, and the like.

[Modification]
FIGS. 7 and 8 are diagrams for explaining a modification of the palletizing apparatus 1 of the above-described embodiment, showing a configuration example in which the fence F is not used. The configuration shown in FIGS. 7 and 8 includes the palletizing device 1 and a detection range Ap1 (FIG. 8 and a detection device that detects an object entering the range Ap2). FIG. 7 shows a configuration example in which palletizing is performed at two positions, pallet position pp1 and pallet position pp2, and FIG. 8 shows a configuration example in which palletizing is performed at three positions, pallet position pp1, pallet position pp2, and pallet position pp3. there is
In the configuration examples shown in FIGS. 7 and 8, an object entering the detection range Ap1 (range Ap2 in FIG. 8) is detected by a sensor such as a laser scanner (not shown). Then, when an entering object is detected in the detection range Ap1, the safety controller 56 instructs the robot controller 55 to stop the robot 2 . As in the previous embodiment, when the robot 2 is a collaborative robot, the robot 2 may be operated while being decelerated under other conditions. Further, in a system including such a palletizing apparatus 1, the robot 2 may be automatically restarted when an incoming object is no longer detected in the detection ranges Ap1 and Ap2. The detection ranges Ap1 and Ap2 have a planar shape above the floor surface and substantially parallel to the floor surface. As a matter of course, since the detection ranges Ap1 and Ap2 are ranges including at least the area separated by the distance X, they may be ranges separated by the distance X or more from the passage space At1 of the robot 2 .

Here, the distance X will be explained. The distance X is the minimum distance at which an intruding object is allowed to approach the passage space At1 when the scanning direction (vertical direction) of the beam emitted by a laser scanner, light curtain, or the like is along the height direction of the intruding object. . The distance X is calculated by Equation (1) described above. Also, K=1600 mm/s and C=1200-0.4H in the formula (1). However, C must be 850 mm or more, and H is the distance (mm) from the reference surface (for example, the floor surface) to the detection ranges Ap1 and Ap2. Therefore, the following formula (5) holds.
X=1600×T+(1200-0.4H) Formula (5)
Also, in a detector that scans light on a plane parallel to the plane containing the approach direction, the height of H should not exceed 1000 mm. Also in this modified example, the stop time of the robot is set to 0.1 sec, and the response time of the safety device such as an optical sensor having a minimum detection capability of 40 mm is set to 0.06 sec.

Moreover, in the case of H=875 mm,
C=1200−0.4×875=850 mm.
For H=900,
Although C=1200−0.4×900=820, C=850 mm in this modified example according to regulations.
Therefore, X in this modified example is obtained as follows.
X=1600×(0.1+0.06)+850=1106mm
Further, by setting the detection height in the horizontal direction to 1000 mm or less and 875 mm or more as described above, the value of C becomes the minimum value of 850 mm, and X can be reduced. Furthermore, if the detection height in the horizontal direction is set to 300 mm or less, risk assessment and protective measures based thereon can be simplified. The installation directions of the detection ranges Ap1 and Ap2 are basically horizontal, but they may be slightly inclined depending on the surrounding conditions.
A detector that scans the light in the vertical direction is preferred because it results in a smaller minimum distance X than in the horizontal direction. However, since the horizontal scanning can detect a wider range than the vertical scanning, the number of detection devices can be reduced, and the cost and control can be simplified, which is preferable. Furthermore, by combining a plurality of detection mechanisms, an automatic pallet conveying unit is not required, and a compact, simple, and inexpensive robotic palletizing apparatus can be provided. In addition, manual work such as correcting the stacking state can be easily performed by a person who has completed the palletizing work or approaches the pallet in the middle of the work.

REFERENCE SIGNS LIST 1... Palletizing device 2... Robot 4... Conveying circumference sensor 5... Robot controllers 11, 12... Boundary sensors 21, 22... Spatial sensors 24, 25... Arm 26... Base 27 Base 28 Rotating parts 31, 32 Entrance/exit sensor 50 Changeover switch 51 Operation panel 52 PLC
53... Relay circuit 55... Robot controller 56... Safety controller 251... End effectors Ab1, Ab2... Prohibited spaces Ao1, Ao2... External space As11... First detection area As12 ... second detection area As21 ... third detection area As22 ... fourth detection area As4 ... fifth detection area As31 ... sixth detection area As32 ... seventh detection area At1, At2 Passage space A Space C Conveyor Cp Entry/exit position F Fences P1, P2 Pallets Sr1, Sr2 Area S Stacked plate surface W・・・ Work pp1, pp2, pp3 ・・・ Pallet position

Claims (9)

A palletizing operation of stacking the goods on the pallet between an input/output position for receiving the goods from or delivering to the conveying part and a pallet position where the pallet on which the goods are stacked or unloaded is installed. Or a palletizing device that performs a depalletizing operation for unloading the articles from the pallet,
robot and
a robot control unit that controls the motion of the robot;
a boundary detection unit connected to the robot control unit;
The boundary detection unit comprises: an entry prohibited space defined outside a passage space through which the robot can pass during the palletizing operation or the depalletizing operation and positioned outside the passage space; At least part of the boundary with the external space is defined as a detection area, and an object passing through the detection area is detected;
When the boundary detection unit detects an object passing through the detection area, the robot control unit stops the robot or reduces the movement speed of the robot ,
A plurality of the pallet positions are set, and the passage space, the entry prohibited space and the external space are set according to each of the plurality of pallet positions,
The robot alternately performs a palletizing operation or depalletizing operation at a first pallet position, which is any one of the plurality of pallet positions, and a palletizing operation or depalletizing operation at a second pallet position, which is the other one of the plurality of pallet positions. go to
The detection area by the boundary detection unit is alternately switched between a first detection area, which is the detection area corresponding to the first pallet position, and a second detection area, which is the detection area according to the second pallet position. further equipped with a switching unit that
the boundary detection unit detects, from the first detection area and the second detection area, a detection area corresponding to the pallet position on the side where the palletizing operation or the depalletizing operation is performed;
further comprising a space detection unit that performs processing for detecting an object in each of the passing space corresponding to the first pallet position and the passing space corresponding to the second pallet position;
The switching unit performs a switching operation of switching between the first detection area and the second detection area on condition that the object is not detected by the processing of the space detection unit,
The robot control unit suspends the switching operation when the space detection unit detects the object through the processing . The robot control unit
2. The apparatus according to claim 1, further comprising monitoring control means for monitoring so that at least part of the robot and the articles gripped by the robot do not move out of the passage space during the palletizing operation or the depalletizing operation. palletizing equipment. The robot control unit
3. The palletizing apparatus according to claim 2, further comprising palletizing control means for controlling said palletizing operation or said depalletizing operation, wherein said palletizing control means and said monitoring control means are independent programs. 4. The palletizing apparatus according to any one of claims 1 to 3, wherein said boundary detection section defines a detection area as a plane defined between said prohibited space and said external space and extending in a vertical direction. . The palletizing device according to any one of claims 1 to 4, wherein the switching section includes a manually operable changeover switch, and the changeover switch switches between the first detection zone and the second detection zone. 6. The space detection unit according to any one of claims 1 to 5 , wherein the detection area is a plane that is above a surface of the stacking plate on which the articles of the pallet are stacked and that intersects the vertical direction. Palletizing equipment. 7. The palletizing apparatus according to any one of claims 1 to 6 , further comprising a conveying periphery detection unit that defines a detection area that is within said passage space and includes the vicinity of said entering/exiting position. 8. The entrance/exit detector according to any one of claims 1 to 7 , further comprising an entrance/exit detector that detects an area through which the pallet passes when it is brought into the pallet position from the outside or carried out from the pallet position to the outside. A palletizing device according to paragraph. 9. The palletizing apparatus according to any one of claims 1 to 8 , further comprising a fence provided so as to surround the robot, the passage space for the robot, and the no-entry space.

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