Patent Description:
A depalletizer is a device that unloads objects loaded on a pallet from the pallet and thus transfers the objects to a conveyor line. After the objects have been loaded on the conveyor line, automation sorting and loading operations are sequentially performed, and in the process of treating delivery objects, accordingly, it is necessary that the objects have to be loaded fast on the conveyor line through the depalletizer.

Recently, automated depalletizing has been introduced using a robot with a gripper adapted to pick up objects packed with boxes. To perform fast loading, in this case, if two or more objects are automatically identified and then picked up simultaneously by the gripper, a loading speed may be more improved. However, there are different kinds of delivery objects, and generally, even the objects loaded on the same pallet are irregular in size and shape, so that there is a need to automatically recognize the objects and pick up them simultaneously.

<CIT> discloses a robot system equipped with a gripper, wherein a depth of a surface of an object to be picked up is sensed.

It is an object of the present invention to provide a depalletizing system and a method for controlling the same that are capable of recognizing, among a plurality of objects loaded on a pallet, two or more objects adjacent to one another and picking up the recognized objects simultaneously.

To accomplish the above-mentioned objects, the present invention provides a depalletizing system in accordance with claim <NUM>, and a method in accordance with claim <NUM>.

According to one aspect of the present invention, there is provided a depalletizing system for picking up a plurality of objects to move the picked up objects to a predetermined position, including: a camera unit for acquiring image data of tops of the plurality of objects; a controller for performing vision recognition for the acquired image data of tops of the plurality of objects to determine whether two neighboring objects among the plurality of objects are simultaneously pickable; and a picking robot for simultaneously picking up the two objects determined as simultaneously pickable objects to move the picked up objects to the predetermined position.

According to the present invention, the picking robot may include a robot arm with a plurality of joints, a gripper connected to one end of the robot arm to suck the objects to be picked up with a pneumatic pressure, and clamps coupled to sides of the gripper in such a manner as to be rotatable around rotary shafts in a longitudinal direction of the gripper.

According to the present invention, the gripper may include a plurality of gripper bodies having a plurality of gripping units mounted thereon to suck the objects to be picked up, and the controller descends at least one of the plurality of gripper bodies according to sizes of the objects to be picked up to allow the descended gripper body to come into contact with the objects to be picked up.

According to the present invention, the controller may determine whether the suction of the objects to be picked up through the gripper and the grasping of the objects to be picked up through the clamps are performed simultaneously according to the sizes of the objects to be picked up.

According to the present invention, the image data may include images or videos.

According to the present invention, the controller may produce a depth map from the image data of tops of the plurality of objects, select any object that has the highest top level among the plurality of objects as a reference object according to the produced depth map, and determine whether the reference object and the neighboring object of the reference object are simultaneously pickable.

According to the present invention, the controller may determine whether the neighboring object of the reference object has the same size and surface image as the reference object to thus determine whether the reference object and the neighboring object are simultaneously pickable according to the determined result.

According to the present invention, if it is determined that the plurality of objects have the same top level as the reference object, the controller may determine that all of the objects are of the same kind to control the picking robot so that the reference object and the neighboring object are picked up simultaneously and moved to the predetermined position.

According to the present invention, the controller may receive master information of the plurality of objects and determine whether the reference object and the neighboring object of the reference object are of the same kind based on the master information.

According to the present invention, the master information may include at least a piece of information of kinds, sizes, weights, delivery addresses, production dates, and current position information of the objects.

According to another aspect of the present invention, there is provided a method for controlling a depalletizing system for picking up a plurality of objects to move the picked up objects to a predetermined position, the method including the steps of: acquiring image data of tops of the plurality of objects; performing vision recognition for the acquired image data of tops of the plurality of objects; determining whether two neighboring objects among the plurality of objects are simultaneously pickable according to a vision recognition result; and simultaneously picking up the two objects determined as simultaneously pickable objects and moving the two objects to the predetermined position.

According to the present invention, the step of performing vision recognition for the acquired image data of tops of the plurality of objects may include the steps of producing a depth map from the image data of tops of the plurality of objects and selecting any object that has the highest top level among the plurality of objects as a reference object according to the produced depth map, and the step of determining whether two neighboring objects among the plurality of objects are simultaneously pickable comprises the step of determining whether the neighboring object of the reference object has the same size and surface image as the reference object to determine whether the reference object and the neighboring object are simultaneously pickable according to the determined result.

According to the present invention, the step of determining whether two neighboring objects among the plurality of objects are simultaneously pickable may include the step of determining, if it is determined that the plurality of objects have the same top level as the reference object, all of the objects are of the same kind to allow the reference object and the neighboring object to be picked up simultaneously.

According to the present invention, the method may further include the steps of: receiving master information of the plurality of objects; and determining whether the reference object and the neighboring object are of the same kind based on the master information.

According to the present invention, the step of simultaneously picking up the two objects determined as simultaneously pickable objects to move the two objects to the predetermined position is carried out by a picking robot including: a robot arm with a plurality of joints; a gripper connected to one end of the robot arm to suck the objects to be picked up with a pneumatic pressure; and clamps coupled to sides of the gripper in such a manner as to be rotatable around rotary shafts in a longitudinal direction of the gripper.

According to the present invention, the gripper may include a plurality of gripper bodies ascended and descended to suck the objects to be picked up and having a plurality of gripping units mounted thereon, respectively, and the step of simultaneously picking up the two objects determined as simultaneously pickable objects to move the two objects to the predetermined position may include the step of descending at least one of the plurality of gripper bodies according to sizes of the objects to be picked up to allow the descended gripper body to come into contact with the objects to be picked up.

According to the present invention, the step of simultaneously picking up the two objects determined as simultaneously pickable objects to move the two objects to the predetermined position may include the step of determining whether the suction of the objects to be picked up through the gripper and the grasping of the objects to be picked up through the clamps are performed simultaneously according to the sizes of the objects to be picked up.

Specific other objects of the present invention will be suggested with reference to the description and attached drawings.

According to the present invention, the depalletizing system and the method for controlling the same can identify the simultaneously pickable objects, without any worker's labor, and pick up them, so that a picking speed is faster than that when only a single object is picked up.

Objects, characteristics and advantages of the present invention will be more clearly understood from the detailed description as will be described below and the attached drawings. However, it is not intended to be exhaustive or to limit the invention to the embodiments as will be disclosed below. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above teachings. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. In the description, the corresponding parts in the embodiments of the present invention are indicated by corresponding reference numerals.

When it is said that one element is described as being "connected" or "coupled" to the other element, one element may be directly connected or coupled to the other element, but it should be understood that another element may be present between the two elements. In contrast, when it is said that one element is described as being "directly connected" or "directly coupled" to the other element, it should be understood that another element is not present between the two elements. A term 'and/or' includes a combination of a plurality of relevant and described items or any one of a plurality of related and described items.

The term 'a' or 'an', as used herein, are defining as one or more than one. The term 'including' and/or 'having', as used herein are intended to refer to the above features, numbers, steps, operations, elements, parts or combinations, and it is to be understood that the terms are not intended to preclude the presence of one or more features, numbers, steps, operations, elements, parts or combinations and added possibilities.

Terms, such as the first, and the second, may be used to describe various elements, but the elements should not be restricted by the terms. The terms are used to only distinguish one element from the other element. For example, a first element may be named a second element without departing from the scope of the present invention.

All terms used herein, including technical or scientific terms, unless otherwise defined, have the same meanings which are typically understood by those having ordinary skill in the art. The terms, such as ones defined in common dictionaries, should be interpreted as having the same meanings as terms in the context of pertinent technology, and should not be interpreted as having ideal or excessively formal meanings unless clearly defined in the specification.

The term 'units' or 'modules', as used herein indicate software components or hardware components such as FPGA or ASIC, and the 'units' or 'modules' perform given operations. However, the 'units' or 'modules' are not limited to software or hardware components. In specific, the 'units' or 'modules' may be disposed on a storage medium addressable, and otherwise, they may serve to play one or more processors. Accordingly, for example, the 'units' or 'modules' may include software components, object-oriented software components, functions, subroutines, segments of program codes, microcodes, circuits, data, database, data structures, tables, arrays, and variables. The functions provided from the components and the 'units' or 'modules' may be combinedly supplied to smaller numbers of components and 'units' or 'modules' or separatedly supplied into additional components or 'units' or 'modules'.

<FIG> is a schematic view showing a depalletizing system according to the present invention.

Referring to <FIG>, the depalletizing system according to the present invention largely includes a picking robot <NUM>, a camera unit <NUM>, and a controller <NUM>.

The picking robot <NUM> serves to pick up a plurality of objects <NUM> loaded on a pallet <NUM> and moved to a picking area to thus load the objects <NUM> on a conveyor line <NUM>. The picking robot <NUM> includes a robot arm with one or more joints movable in various directions and a gripper connected to one end of the robot arm.

According to the present invention, in specific, the picking robot <NUM> picks up two or more objects adjacent to one another simultaneously pickable according to a determination result of the controller <NUM> and loads the picked up objects on the conveyor line <NUM>.

An operation of loading the plurality of objects <NUM> loaded on the pallet <NUM> on the conveyor line <NUM> through the picking robot <NUM> is exemplarily shown in <FIG>, but the present invention is not limited thereto. For example, the picking robot <NUM> may move the plurality of objects loaded on one pallet to another pallet or move a plurality of objects moving along the conveyor line to a pallet or another conveyor line. That is, the picking robot <NUM> may move the plurality of objects <NUM> to predetermined positions under the control of the controller <NUM>.

The camera unit <NUM> acquires image data of tops of the plurality of objects <NUM> loaded on the pallet <NUM>. The image data of tops of the plurality of objects <NUM>, which is acquired by the camera unit <NUM>, is provided to the controller <NUM>, and next, it is determined whether the simultaneously pickable objects exist among the plurality of objects <NUM>.

The controller <NUM> controls the picking operation of the picking robot <NUM> based on the image data of the objects acquired by the camera unit <NUM>. The controller <NUM> performs vision recognition for the image data of tops of the objects acquired by the camera unit <NUM> and determines the objects simultaneously pickable according to the recognition result.

<FIG> is a perspective view showing the picking robot of the depalletizing system of <FIG>.

Referring to <FIG>, the picking robot <NUM> includes a robot arm <NUM> freely movable and a gripper <NUM> connected to one end of the robot arm <NUM>.

The robot arm <NUM> extends from a body <NUM> of the picking robot <NUM> and has one or more joints to move the gripper <NUM> to an arbitrary direction among first to third directions of X, Y, and Z. The robot arm <NUM> moves the gripper <NUM> according to a control command provided by the controller <NUM>, grips the pickable objects, and loads the gripped objects on the conveyor line <NUM>.

The gripper <NUM> sucks tops of the objects to be picked up or clamps sides of the objects to grip the objects. An explanation of a configuration and operation of the gripper <NUM> will be given with reference to <FIG>.

<FIG> are rear and side views showing the gripper of the picking robot of <FIG>.

Referring to <FIG>, the top of the gripper <NUM>, which is viewed in the third direction of Z, is shown in <FIG>, the side of the gripper <NUM>, which is viewed in the first direction of X, is shown in <FIG>, and the side of the gripper <NUM>, which is viewed in the second direction of Y, is shown in <FIG>.

The gripper <NUM> includes gripper bodies <NUM> having a plurality of gripping units <NUM> mounted thereon and clamps <NUM> mounted on the sides of the gripper bodies <NUM>.

As shown in <FIG>, the gripper <NUM> includes four gripper bodies <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> arranged in a 2x2 block form. However, the arrangement is just exemplary, and therefore, the gripper <NUM> may have a lattice arrangement of four or more or less gripper bodies <NUM>.

The gripper bodies <NUM> are connected to a plate <NUM> through connectors <NUM>. According to embodiments of the present invention, when the gripper <NUM> picks up objects, at least one of the gripper bodies <NUM>-<NUM> to <NUM>-<NUM> protrudes from the plate <NUM>. In specific, for example, the connectors <NUM> each having a pneumatic cylinder and a piston move to the opposing direction to the plate <NUM> to allow the gripper bodies <NUM> to protrude from the plate <NUM> toward the objects.

The controller <NUM> selects at least one of the gripper bodies <NUM> based on widths of the pickable objects identified through the vision recognition and thus controls an ascending operation for the selected gripper body <NUM>. According to embodiments of the present invention, if it is determined through the controller <NUM> that the plurality of objects adjacent to one another are simultaneously pickable, the controller <NUM> selects at least one of the gripper bodies <NUM> that is descended based on sum of widths of the plurality of objects simultaneously pickable in the first and second directions of X and Y.

Further, the plurality of gripper bodies <NUM> are adjustable in distance in the first direction of X and the second direction of Y, respectively. In specific, a distance between the gripper body <NUM>-<NUM> and the gripper body <NUM>-<NUM> in the second direction of Y is adjustable, and a distance between the gripper body <NUM>-<NUM> and the gripper body <NUM>-<NUM> in the first direction of X is adjustable. Two gripper bodies (for example, <NUM>-<NUM> and <NUM>-<NUM>) are fitted to one ball screw and thus connected to each other, together with a motor, and through the operation of the motor, the distance between the gripper bodies in the second direction of Y is adjustable.

The distance between the plurality of gripper bodies <NUM> in the first direction of X or the second direction of Y is controlled according to the widths of the pickable objects in the first direction of X or the second direction of Y.

The plurality of gripping units <NUM> are coupled to the plurality of gripper bodies <NUM>, respectively. The gripping units <NUM> serve to suck the pickable objects with pneumatic pressures received from pneumatic pressure supply means connected thereto, to detach the sucked objects with static pressures received from the pneumatic pressure supply means, and to load the objects onto the conveyor line <NUM>.

The clamps <NUM> are coupled to the gripper bodies <NUM> in such a manner as to be rotatable around rotary shafts <NUM> in longitudinal directions of the gripper bodies <NUM>. The clamps <NUM> rotate in rotating directions R and become close to or away from the objects to be picked up. The clamps <NUM>, which become close to the suckedly picked up objects onto the gripping units <NUM>, come into contact with the picked up objects by means of gripping portions <NUM>, thereby enabling stable picking.

As shown in <FIG>, the plurality of clamps <NUM> are provided correspondingly to the plurality of gripper bodies <NUM>-<NUM> to <NUM>-<NUM>.

In the picking operation, the clamps <NUM> can selectively operate. In the picking operation, in specific, the controller <NUM> rotates, among the plurality of clamps <NUM>-<NUM> to <NUM>-<NUM>, at least one pair of clamps (for example, the clamps <NUM>-<NUM> and <NUM>-<NUM> and/or clamps <NUM>-<NUM> and <NUM>-<NUM>) facing each other to clamp the objects based on the widths of the pickable objects identified through the vision recognition.

According to the present invention, if it is determined through the controller <NUM> that the plurality of objects adjacent to one another are simultaneously pickable, the controller <NUM> selects the clamps <NUM> to rotate among the plurality of clamps <NUM> based on sum of widths of the plurality of objects simultaneously pickable in the first and second directions of X and Y.

<FIG> is a perspective view showing the camera unit and an image processing unit of the depalletizing system according to the present invention.

Referring to <FIG>, the camera unit <NUM> includes an upper camera <NUM> and a lower camera <NUM> for acquiring images of tops of the objects <NUM> loaded on the pallet <NUM>. The upper camera <NUM> and the lower camera <NUM> are disposed on a stand <NUM> with a given height to acquire the image data of the tops of the objects <NUM>. The upper camera <NUM> is coupled to a support frame <NUM> attached to the stand <NUM> through an adjustable frame <NUM> that is adjusted in angle by means of rotation.

The image data of the tops of the objects <NUM>, which is acquired by the camera unit <NUM>, includes, for example, images or videos.

The upper camera <NUM> and the lower camera <NUM> of the camera unit <NUM>, which are disposed in parallel with each other in the third direction of Z, while having different heights, are shown in <FIG>, but the present invention is not limited thereto. The camera unit <NUM> may have two cameras disposed in parallel with each other in a horizontal direction or just a single camera to thus acquire the image data of the tops of the objects <NUM>.

The camera unit <NUM> transmits the acquired image data of the tops of the objects <NUM> to the controller <NUM>. The controller <NUM> identifies the objects simultaneously pickable based on the result of the vision recognition through the received image data of the tops of the objects <NUM>. If the controller <NUM> identifies the objects simultaneously pickable, the controller <NUM> controls the picking robot <NUM> to allow the objects to be picked up simultaneously.

The controller <NUM> is a module that includes at least one or more processors and a set of memories to which the processors access to read and write data and storing commands executed by the processors. For example, the controller <NUM> includes various computer systems such as a personal computer (PC), a server computer, a workstation, a laptop computer, and the like. According to the present invention, the controller <NUM> may include a set of a plurality of computer systems.

The picking robot <NUM>, the camera unit <NUM>, and the controller <NUM> are connected to one another through well known wired/wireless network protocols, which will not be explained below for the brevity of the description.

<FIG> is a flowchart showing a method for controlling a depalletizing system according to the present invention.

Referring to <FIG>, the method for controlling a depalletizing system according to the present invention includes the steps of acquiring image data of tops of a plurality of objects loaded on a pallet and moved to a picking area (at step S110), performing vision recognition for the acquired image data of the tops of the plurality of objects (at step S120), determining whether among the plurality of objects, two or more objects adjacent to one another are simultaneously pickable (at step S130), and picking up the two or more simultaneously pickable objects and loading the picked up objects on a conveyor line (at step S140).

First, the plurality of objects <NUM> loaded on the pallet <NUM> move to the picking area, and the image data of tops of the plurality of objects <NUM> is acquired by the camera unit <NUM> (at step S110). The picking area indicates an area where picking operations for the objects are carried out by a picking robot <NUM> of the depalletizing system, and the objects <NUM> are loaded on the pallet <NUM> and moved to the picking area through a fork lift truck, and otherwise, the pallet on which the objects <NUM> are loaded is moved to the picking area through the conveyor line.

According to the present invention, a controller <NUM> receives master information of the plurality of objects <NUM> loaded on the pallet <NUM> after the plurality of objects <NUM> have been moved to the picking area. The master information of the plurality of objects <NUM> may include kinds, sizes, weights, delivery addresses, production dates, and current position information on the pallet <NUM> of the objects, but the present invention is not limited thereto. According to the present invention, the controller <NUM> determines whether two or more objects simultaneously pickable exist using the information of the objects <NUM>, which will be described below.

The camera unit <NUM> is configured to have adjustable frames <NUM> set at angle so that the camera unit <NUM> is located toward the tops of the objects <NUM> disposed on the picking area. For example, the camera unit <NUM> acquires two sheets of image data of the tops of the objects <NUM> photographed by an upper camera <NUM> and a lower camera <NUM>. However, the present invention is not limited thereto, and the camera unit <NUM> may acquire the image data of the tops of the objects <NUM> through two cameras disposed in parallel with each other in a horizontal direction or just a single camera.

Next, the acquired image data of the tops of the plurality of objects <NUM> by the camera unit <NUM> is provided to the controller <NUM>, and the vision recognition for the image data is carried out by the controller <NUM> to determine whether among the plurality of objects <NUM>, two or more objects adjacent to one another are simultaneously pickable. The steps will be explained in detail with reference to <FIG>.

<FIG> is a flowchart showing some steps of the method for controlling a depalletizing system according to the present invention.

Referring to <FIG>, a depth map of the acquired image is produced through the controller <NUM> (at step S210).

The depth map is an image that contains information relating to the distance of the camera unit <NUM> as a viewpoint of the objects <NUM> from the surfaces of the objects <NUM>. In specific, the depth map is produced to obtain height information of the tops of the objects <NUM> and to determine whether the objects adjacent to one another exist. In this case, the depth map can be used in determining reference objects to be picked up next time through the controller <NUM>.

<FIG> are views showing depth map production conducted by the depalletizing system according to the present invention.

Referring to <FIG>, the image of tops of the objects <NUM> placed on a floor, which is photographed by the camera unit <NUM>, is shown in <FIG>, and a depth map 1000a, which is produced for the image of <FIG>, is shown in <FIG>.

As shown in <FIG>, the depth map 1000a indicates an area at which a height is highest, that is, an area nearest to the camera unit <NUM> with a blue color with a low wavelength and an area at which a height is lowest, that is, an area most distant from the camera unit <NUM> with a red color with a high wavelength. However, the depth map visualized as shown in <FIG> is exemplary, and accordingly, the depth map is enough only if it contains data of heights of points of the acquired image data of tops of the objects <NUM>.

After that, the controller <NUM> selects the reference object that has the highest top level among the plurality of objects based on the depth map produced (at step S220).

The controller <NUM> recognizes the shapes of the individual objects distinguished by their respective boxes from the plurality of objects <NUM>. For example, the controller <NUM> recognizes the individual objects through edge detection for generally square tops of the individual objects contained in the acquired image data of the tops of the objects <NUM>, and if necessary, the controller <NUM> recognizes the individual objects with reference to the depth map produced. The controller <NUM> recognizes information of the individual objects, identifies the top levels, images, and widths and lengths of the objects from the image data, and stores the identified information together with the information of the individual objects.

The controller <NUM> selects the reference object having the highest top level based on the obtained information of the individual objects. The reference object is one of the objects that is located at the uppermost position of the plurality of objects <NUM> loaded on the pallet <NUM> and is picked up directly by the picking robot <NUM>, and if the reference object is selected, the picking operation is taken by the picking robot <NUM>.

The controller <NUM> determines whether the tops of the plurality of objects have the same height as the top of the reference object (at step S230). In this case, the same height may include numerically the same height as the heights of the objects identified from the depth map as well as a height calculated in consideration of a measurement error occurable. Accordingly, it is determined that the object having a height difference in a predetermined range (for example, <NUM>%) from the top height of the reference object has the same height as the reference object.

If it is determined that there is no object having the same height as the reference object, the controller <NUM> determines that different kinds of objects are loaded on the pallet <NUM> and allows only the reference object to be picked up, without allowing two or more objects to be simultaneously picked up, to load the picked up reference object on the conveyor line (at step S280).

Contrarily, if it is determined that only the objects having the same height as the reference object are loaded on the pallet <NUM>, the controller <NUM> determines that the same kind of objects are loaded on the pallet <NUM> and allows the picking robot <NUM> to pick up the objects adjacent to the reference object simultaneously to load the picked up objects on the conveyor line (at step S270). In this case, the same kind of objects indicate that the same kind of objects as the reference object are packed in boxes with the same size and shape as one another.

If it is determined through the controller <NUM> that the same kind of objects are loaded on the pallet <NUM>, the picking robot <NUM> picks up simultaneously two or more objects including the reference object and loads the picked up objects on the conveyor line until all of the objects loaded on the pallet <NUM> are loaded on the conveyor line.

According to the present invention, before it is determined through the controller <NUM> that the same kind of objects are loaded on the pallet <NUM>, the controller <NUM> may refer to information of the plurality of objects that has been provided thereto. In specific, if it is recognized that the plurality of objects <NUM> loaded on the pallet <NUM> have tops with the same height as one another based on the information of kinds, weights, delivery addresses, and production dates of the objects <NUM> which have been provided to the controller <NUM> when the objects <NUM> are moved to the picking area, the recognized result and the information of the objects <NUM> are combined to each other, so that the controller <NUM> determines that the same kind of objects are loaded on the pallet <NUM>. Accordingly, the controller <NUM> complementarily utilizes the image data of the tops of the objects <NUM> acquired through the camera unit <NUM> and the information of the objects <NUM> to improve accuracy in the determination.

Otherwise, if it is determined that some of the plurality of objects <NUM> loaded on the pallet <NUM> have tops with the same height as tops of the reference object, the controller <NUM> determines whether the objects with the same height as the reference object are pickable simultaneously, together with the reference object, according to references as will be discussed below.

The controller <NUM> determines whether the objects and the reference object are within a distance gripped by the gripper <NUM> (at step S240). Even though the objects with the same height as the reference object exist among the plurality of objects <NUM> loaded on the pallet <NUM>, the objects and the reference object may be far away from each other or may not be alignedly loaded with one another, and in this case, the objects and the reference object cannot be picked up simultaneously. The step of determining whether the neighboring objects of the reference object are within a predetermined separation distance from the reference object and within a perpendicular distance with respect to the reference object through the controller <NUM> will be explained with reference to <FIG>.

<FIG> is a view showing separation distance and perpendicular distance determinations conducted by the depalletizing system according to the present invention.

Referring to <FIG>, the reference object B1 and another object B2 are adjacent to each other. A first surface F1 of the reference object B1 faces a second surface F2 of the neighboring object B2. That is, the first surface F1 and the second surface F2 face each other, while having no object placed between the reference object B1 and the neighboring object B2.

A distance between the first surface F1 and the second surface F2 is defined as a separation distance D1. If the reference object B1 and the neighboring object B2 are arranged in a state where the first surface F1 and the second surface F2 are not parallel with each other, a distance between the facing surfaces F1 and F2 is measured in a plurality of positions, and the mean value of the measured values is determined as the separation distance D1.

A perpendicular distance D2 between the reference object B1 and the neighboring object B2 indicates a degree of misalignment between the reference object B1 and the neighboring object B2, which is defined as a distance between an extension line from a surface F3 connected to the first surface F1 of the reference object B1 and a surface F4 connected to the second surface F2 of the neighboring object B2.

Only when at least one of the separation distance D1 and the perpendicular distance D1 between the reference object B1 and the neighboring object B2 is within a predetermined reference value, the controller <NUM> determines whether the reference object B1 and the neighboring object B2 are pickable simultaneously. However, if it is determined that at least one of the separation distance D1 and the perpendicular distance D1 between the reference object B1 and the neighboring object B2 is over the predetermined reference value, the controller <NUM> determines that the reference object B1 and the neighboring object B2 cannot be picked up simultaneously. Further, if there is no neighboring object satisfying the above-mentioned conditions of the separation distance D1 and the perpendicular distance D1, the controller <NUM> controls the picking robot <NUM> so that only the reference object is picked up and loaded on the conveyor line (at step S280).

The controller <NUM> compares the width and length of the reference object B1 to those of the neighboring object B2 and the top image of the reference object B1 to that of the neighboring object B2 (at step S250). The controller <NUM> compares the sizes and the top images between the reference object B1 and the neighboring object B2 based on the image data of tops of the plurality of objects <NUM> acquired before.

If it is measured that the width and length of the reference object B1 are within a predetermined range (for example, <NUM>%) with respect to those of the neighboring object B2, the controller <NUM> determines that the reference object B1 and the neighboring object B2 have the same size as each other.

Further, the comparison between top images of the reference object B1 and the neighboring object B2 is carried out through the comparison between the images printed on tops of the boxes of the reference object B1 and the neighboring object B2 and tape images attached to the boxes thereof.

According to the present invention, the controller <NUM> may utilize pre-stored master information of objects in comparing the sizes and images between the reference object B1 and the neighboring object B2.

<FIG> is a photograph showing a determination as to whether objects are simultaneously pickable that is conducted by the depalletizing system according to the present invention.

Referring to <FIG>, the step of determining whether the reference object B1 and the neighboring objects B2 and B3 are simultaneously pickable is visualized. The controller <NUM> determines whether the neighboring objects B2 and B3 with the surfaces facing the reference object B1 among the plurality of objects <NUM> loaded on the pallet <NUM> are of the same kind as the reference object B1. If it is determined that the neighboring object B2 satisfies the same size and image conditions as the reference object B1, the neighboring object B2 is determined as a simultaneously pickable object, together with the reference object B1.

A graphic expression as shown in <FIG> is just exemplary, and accordingly, of course, the controller <NUM> may perform the determination only through internal data processing, without any output of such a graph.

The controller <NUM> determines whether the reference object B1 and the neighboring object B2 are of the same kind through the comparison between the sizes and top images between the reference object B1 and the neighboring object B2, and if it is determined that they are of the same kind (at step S260), the controller <NUM> controls the picking robot <NUM> so that the reference object B1 and the neighboring object B2 are picked up simultaneously and loaded on the conveyor line (at step S270). Otherwise, if it is determined that they are not of the same kind, the controller <NUM> controls the picking robot <NUM> so that only the reference object B1 is picked up and loaded onto the conveyor line (at step S280).

In summary, the depalletizing system according to the present invention determines the object having the highest top level as the reference object through the vision recognition for the plurality of objects <NUM> loaded on the pallet <NUM> and moved to the picking area, picks up the object having the same shape as the reference object among the neighboring objects and the reference object simultaneously, and loads the picked up objects on the conveyor line <NUM>.

Accordingly, the simultaneously pickable objects are identified, without any worker's labor, and picked up. In this case, a picking speed is faster than that when a single object is picked up. For example, if simultaneously pickable objects on one pallet are occupied to a rate of <NUM>%, the depalletizing system according to the present invention may reduce the picking time by about <NUM>% when compared to the existing system that picks up a single object.

<FIG> is an exemplary view showing the picking work conducted by the depalletizing system according to the present invention.

Referring to <FIG>, the reference object B1 and the neighboring object B2 are picked up simultaneously through the control of the controller <NUM>.

The controller <NUM> aligns the center of the pickable objects with the center of the gripper <NUM> before picking up the objects. If the pickable object is just one reference object B1, the center of the reference object B1 is aligned up and down with the center of the gripper <NUM>. If the pickable objects include the reference object B1 and the neighboring object B2, the center of the gripper <NUM> is aligned up and down with the center of the two objects in consideration of the separation distance (See D1 of <FIG>) and the perpendicular distance (See D2 of <FIG>) of the two objects.

The controller <NUM> selectively operates some of the four gripper bodies <NUM> according to the widths of the first and second directions of X and Y of the objects B1 and B2 pickable simultaneously. The selected gripper bodies among the four gripper bodies <NUM> are descended until the gripping units <NUM> come into contact with the objects and grip the objects. According to the present invention, the distance between the two gripper bodies (for example, the gripper bodies <NUM>-<NUM> and <NUM>-<NUM> or the gripper bodies <NUM>-<NUM> and <NUM>-<NUM>) is increased or decreased.

Further, at least one pair of clamps <NUM>-<NUM> and <NUM>-<NUM> and/or one pair of clamps <NUM>-<NUM> and <NUM>-<NUM> facing each other in the first direction of X additionally operate according to the widths of the simultaneously objects pickable. In specific, in a state where the objects are sucked on the gripping units <NUM>, at least one pair of clamps <NUM>-<NUM> and <NUM>-<NUM> and/or one pair of clamps <NUM>-<NUM> and <NUM>-<NUM> rotate around their rotary shafts <NUM> in the rotating directions R and grasp the objects, thereby enabling stable picking. Otherwise, if the pickable objects have smaller widths than a predetermined width, that is, smaller widths than the width of the gripper <NUM> in the first direction of X to cause the grasping through the clamps <NUM> to be ineffective, the controller <NUM> does not operate the clamps <NUM> in the picking process.

If the objects are gripped through the gripper <NUM>, the robot arm <NUM> moves the gripper <NUM> to the conveyor line <NUM>. The gripper <NUM> releases the objects from their gripping state on the conveyor line <NUM>. That is, the clamps <NUM> are open, and the gripping units <NUM> receive static pressures, so that the objects fall down onto the convey line <NUM>.

Up to now, the preferred embodiments of the present invention have been disclosed in the specification and drawings. Therefore, persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above teachings. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.

Claim 1:
A depalletizing system for picking up a plurality of objects to move the picked up objects to a predetermined position, comprising:
a camera unit (<NUM>) for acquiring image data of tops of the plurality of objects;
a controller (<NUM>) for performing vision recognition for the acquired image data of tops of the plurality of objects to determine whether two neighboring objects among the plurality of objects are simultaneously pickable; and
a picking robot (<NUM>) for simultaneously picking up the two objects determined as simultaneously pickable objects to move the picked up objects to the predetermined position,
wherein the controller (<NUM>) produces a depth map from the image data of tops of the plurality of objects and selects any object that has the highest top level among the plurality of objects as a reference object according to the produced depth map,
characterized in that
the controller (<NUM>) determines whether the neighboring object of the reference object has the same size and surface image as the reference object to determine whether the reference object and the neighboring object are simultaneously pickable according to the determined result.