Abstract:
Techniques that palletize bundles at high-speed. A robotic controller includes a vision system that determines a location and orientation of incoming bundles, a tracking system that communicates between the controller and a conveyor, and a robot that coordinates its movement with the bundles. The tracking system identifies the location and orientation of each bundle, informs the controller, and causes the robot to track its location and orientation with incoming bundles. The controller receives information on the location and orientation of each bundle. The controller instructs the robot to move in coordination with each incoming bundle, instructs the robot where and at what orientation to pick up the bundle, and instructs the robot how to move the bundle to a tier-and-stacking position. The controller can instruct the robot how to pick up each bundle on the fly as the bundle moves into range on the incoming conveyor.

Description:
BACKGROUND 
     1. Field of the Disclosure 
     This application generally relates to palletizers, such as for corrugated bundles, and related matters. 
     2. Background of the Disclosure 
     Manufacturing operations often use conveyors to move products as they are produced, and after they are produced, onto a device where finished products are bundled and stacked onto a pallet. The latter type of device is sometimes called a “palletizer”. 
     It sometimes occurs that stacking finished products involves a number of operations, such as rotating the bundle, positioning the bundle, and squaring its location with respect to the stack. This can mean that stacking bundles can take a relatively long time to occur, which can slow the production line, or alternatively, cause the stacking operation to produce lesser-quality stacks. This can cause difficulty when it is desired to stack bundles relatively quickly, such as when the production line is operating relatively quickly, or when a finishing device that is processing the bundles is operating relatively quickly. 
     It also sometimes occurs that stacking finished products involves placing the bundle onto a tier, such as organizing bundles into a pattern while they are stacked. This can occur when the bundles are placed in an arrangement other than a linear stack, such as to provide support in the event that the stack of bundles might sway or tilt. This can cause difficulty when combining tier placement and stacking, as another tier of bundles cannot generally be positioned until the stack of such tiers is “squared up” or otherwise stabilized. 
     Each of these examples, as well as other possible considerations, can cause difficulty in aspects of a manufacturing production system that includes an operation for relatively high-speed palletizing. This problem might be an issue when palletizing bundles for a relatively high-speed production line, or when palletizing bundles when a relatively high-speed finishing device is processing the bundles. 
     BRIEF SUMMARY OF THE DISCLOSURE 
     This application provides techniques that palletize bundles at relatively high-speed, even when the bundles are organized in tiers and stacked. 
     In one embodiment, a palletizer system includes tier placement elements, tier squaring elements, and tier stacking elements. For example, the tier placement elements can include robotic placement of bundles into layers or tiers, the tier squaring elements can include squaring-up elements, and the tier stacking elements can include elements for further stacking of tiers. By separating the tier placement elements from the tier squaring elements, the palletizer can operate at superior speed. 
     In one embodiment, a robotic controller element includes a vision system that determines a location and orientation of incoming bundles, an integrated conveyor tracking system that communicates between the robotic controller element and a movable bundle conveyor, and a robotic element that coordinates its movement with incoming bundles as they arrive on the conveyor. For example, the vision system can include a three dimensional (3D) vision system, a line scanner, a color vision system, or another system usable with relatively high-speed moving goods. 
     In one embodiment, the conveyor tracking system identifies the location and orientation of each incoming bundle on the conveyor, informs the robotic controller element of that location and orientation, and causes the robotic element to track its location and orientation with incoming bundles. The robotic controller element receives information with respect to the location and orientation of each incoming bundle. The robotic controller element instructs the robotic element to move in coordination with the location and orientation of the incoming bundle, instructs the robotic element with respect to where and at what orientation to pick up the bundle, and instructs the robotic element how to move the bundle to a tier-and-stacking position. For example, the robotic controller can instruct the robotic element how to pick up each bundle on the fly as the bundle moves into range on the incoming conveyor. Single layered or multilayer tiers may be formed in the tier-and stacking position. 
     In one embodiment, once the robotic element has picked up the bundle and placed it in a tier-and-stacking position, the bundle can be conveyed to tier squaring elements, which can operate separately from the robotic element. The tier squaring elements can square-up the tier independently of the robotic element, which allows the robotic element to begin operation with another set of bundles, without waiting for the tier squaring elements to perform any functions. Completed stacks of bundles may be formed in a stack building area. In one embodiment, two or more previously formed multi-layered tiers may be gathered together and combined into a completed stack in the stack build area. 
     After reading this application, those skilled in the art would recognize that techniques shown in this application are applicable to fields and information other than bundle palletizing systems, robotic systems, or vision systems. In the context of the invention, there is no particular requirement for any such limitation. Moreover, after reading this application, those skilled in the art would recognize that techniques shown in this application are applicable to methods and systems other than those involving manufacturing of physical devices such as boxes or stackable materials. For example, other manufacturing contexts can include assembly lines, chemical processes, semiconductor manufacturing, and otherwise. 
     While multiple embodiments are disclosed, including variations thereof, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure. As will be realized, the disclosure is capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  shows a conceptual drawing of a robotic controller system. 
         FIG. 2  shows a conceptual drawing of a palletizer. 
         FIG. 3-1 through 3-52  (collectively referred to as  FIG. 3 ) show a conceptual drawing of a method of layering or tiering. 
         FIG. 4-1 through 4-2  (collectively referred to as  FIG. 4 ) show a conceptual drawing of another method of layering or tiering. 
         FIG. 5  is a perspective view of a six-layered tier built in the tier build area using the method illustrated in the  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
     Example Robotic Controller System 
       FIG. 1  shows a conceptual drawing of a robotic controller system. 
     In one embodiment, a robotic controller system  100  can include elements as shown in the figure, including at least the following: a robot  110 , a robot controller  120 , a bundle conveyor  130 , a vision system  140 , a conveyor tracking system  150 , a palletizer control system  160 , a tier build conveyor  170 , and possibly other elements. 
     Robotic Elements. 
     In one embodiment, the robot  110  can include one or more robotic arms that can grip one or more bundles and lift them from an incoming conveyor. The one or more robotic arms can each include a grabbing apparatus (not shown in  FIG. 1 ), such as a fork or a friction gripper, that can seize each bundle in turn and remove that bundle from the conveyor. The one or more robotic arms can each include a lifting apparatus (not shown in  FIG. 1 ), such as a hydraulic arm that can raise or lower the bundles, such as once they are gripped, and move them upward from the conveyor. The one or more robotic arms can each include a rotating or translating apparatus (not shown in  FIG. 1 ) that can move the bundles from the conveyor, such as once they are lifted from the conveyor, to another location. References herein to lifting bundles are to be understood to refer to any suitable method for gripping and moving bundles. For example, in some embodiments, lifting bundles refers to sliding bundles into position, and in other contexts, lifting can refer to raising by any desired or suitable amount, including between about 0 inches and about 6 inches or higher, between about 0 inches and about 3 inches, between about 0.25 inches and 2 inches, or about 0.5 inches. 
     In alternative embodiments, the robot  110  can include a zero (or low) pressure accumulation conveyor, such as one or more vacuum grip elements disposed to seize bundles or sets of flat sheets, in the event that ordinary procedures for gripping and moving bundles are interrupted or slowed. For example, if bundles are stacked properly by the palletizer, but a post-palletizer finishing process is interrupted or otherwise slowed to a point that stacking is interrupted, a variable speed robot  110  can resequence the bundles in response to the interruption. In such cases, the variable speed robot  110  can include a zero (or low) pressure accumulation conveyor, or both a zero (or low) pressure accumulation conveyor and one or more robotic arms with gripping apparatus. 
     In one embodiment, the robot  110  can operate under the control of the robot controller  120 . The robot controller  120  can include a processor, program and data memory (such as non-transitory memory or mass storage), and instructions. The instructions can be maintained in the program and data memory and interpretable by the processor to alter the state of the robot controller  120 , to direct the robot  110  to perform one or more actions, or otherwise. For example, the robot controller  120  can include a personal computer (PC) or a programmable logic controller (PLC). The PLC or PC can be coupled to the robot  110  and be disposed to receive status information from the robot  110 , and to send control signals or other information to the robot  110 . This can have the effect of directing the robot  110  to move and to otherwise change state as directed by the robot controller  120 . 
     In one embodiment, the bundle conveyor  130  (herein sometimes called just a “conveyor”) includes devices and structure capable of moving bundles toward the robotic controller system  100 , such as bringing bundles in from a relatively remote area, such as another device or processing station. For example, the conveyor  130  can include a moving belt, such as a continuous belt having a top side and a bottom side, disposed in a substantially continuous loop, or a slanted pathway, such as including rollers or ball belts that allow bundles to roll or slide from a device toward the robotic controller system  100 , or otherwise. In such examples, bundles are positioned on the conveyor  130 , which moves them toward the robotic controller system  100 . 
     In one embodiment, the vision system  140  can include one or more devices that view bundles as they are conveyed by the conveyor  130 . For example, the vision system  130  can include an external sensor that can recognize one or more bundles as distinct objects, and can identify the relative location and the relative orientation of those bundles with respect to the robot  110  and each other. In such examples, the vision system  130  can include a three dimensional (3D) vision sensor, such as can be disposed to identify lines, occlusion, shadows, and other indicia of solid objects. This can have the effect of providing information with respect to locations of one or more bundles, and orientation of one or more bundles. 
     In one embodiment, the vision system  140  can operate with respect to individual bundles, or can operate with respect to pairs of bundles (such as when bundles are conveyed by the conveyor  130  in pairs), or with respect to other numbers of bundles. In alternative embodiments, the vision system  140  can operate to identify the amount and shape of spaces between bundles. This can have the effect that the robotic controller system  100  can identify the location of bundles in response to an amount of spacing, and the orientation of bundles in response to a shape of the spaces between bundles. 
     In one embodiment, the conveyor tracking system  150  can include one or more devices that move the robot  110  with respect to the conveyor  130 , so as to maintain the robot  110  in generally the same relative position with respect to one or more bundles. For example, as a bundle is moved by the conveyor  130 , the conveyor tracking system  150  can move the robot  110  at generally the same speed and in substantially the same direction as the bundle. 
     This can first have the effect that the robot  110  maintains a position that allows the robot  110  to grip and pick up the bundle from the conveyor  130 , with relatively rapid speed, without first having to position the robot  110  with respect to the bundle. This can second have the effect that the robot  110  can pick the bundle from the conveyor  130 , without having to match speed or orientation between the robot  110  and the bundle as the latter is moved on the conveyor  130 . These can have the effect of substantially reducing latency with respect to picking the bundle from the conveyor  130 , when the robot controller  120  directs the robot  110  to pick the bundle. 
     In one embodiment, the palletizer control system  160  can include devices and structures as described herein, such as with respect to  FIG. 2 . For example, the palletizer control system  160  can include a control system disposed to cause elements of the palletizer to perform method steps or other techniques as described herein. In such examples, the palletizer control system  160  can include a processor and program and data memory, the program and data memory including instructions interpretable by the processor to direct the palletizer, its devices, or other devices, to perform method steps as described herein. 
     In one embodiment, the tier build conveyor  170  can include devices and structures as described herein, such as with respect to  FIG. 2 . For example, the tier build conveyor  170  can include a conveyor disposed to receive bundles placed by the robot  110 , allow the robot  110  to position those bundles in tiers, and move those tiers to downstream devices and structures in the palletizer. 
     Example Palletizer 
       FIG. 2  shows a conceptual drawing of a palletizer. 
     In one embodiment, a palletizer can include elements as shown in the figure, including at least the following: the robot  110 , robot controller  120 , bundle conveyor  130 , vision system  140 , palletizer control system  160 , and tier build conveyor  170 , such as described above with respect to  FIG. 1 . The palletizer can also include one or more of a bundle pick area  210 , a tier build area  220 , a tier squaring area  230 , a tie sheet hopper  231 , a tier center divider  232 , a tier lift element  240 , a stack build area  250 , a stack exit conveyor  251 , a bottom sheet conveyor  252 , a bottom sheet hopper  253 , and possibly other elements. 
     In one embodiment, as described herein, the palletizer can operate with respect to one or more incoming bundles  201 . 
     PALLETIZER CONTROL SYSTEM. In one embodiment, the palletizer control system  160 , as described below, can identify the location and orientation of the bundles  201  as they are conveyed into the palletizer. 
     The palletizer control system  160  can receive the bundles  201  from the conveyor  130 , such as at the bundle pick area  210 . As the bundles  201  are moved by the conveyor  130 , the bundles  201  are identified by the vision system  140 , which can identify the location and orientation of those bundles  201 . For example, the bundle pick area  210  can include a region in which the vision system  140  operates, or in which the vision system  140  can determine the presence of bundles  201 , or in which the vision system  140  can determine the location or orientation (or both) of bundles  201 . 
     In one embodiment, the bundles  201  can be placed in one or more identifiable specified locations, with the effect that the vision system  140  can relatively easily identify the bundles  201  as or when they arrive in the bundle pick area  210 . This can have the effect that the bundles  201  are restricted to one of only a relatively few possible locations and orientations in the bundle pick area  210 . For a first example, the bundles  201  can arrive or be placed in a sequence of detents, trays, or other apparatus that maintains the bundles  201  in relatively well-known locations and orientations. For a second example, the bundles  201  can be spaced as they arrive, with the effect that each pair of those bundles can be relatively easily distinguished. 
     In a first set of such examples, the bundles  201  can arrive or be placed in such relatively few possible locations and orientations before they arrive in the bundle pick area  210 , such as while they are on the conveyor  130 . In a second set of such examples, the bundles  201  can arrive or be placed in such relatively few possible locations and orientations as (or after) they arrive in the bundle pick area  210 , such as in response to a device or structure within the bundle pick area  210 . This can have the effects that the vision system is subject to relatively fewer errors in identifying bundles  201 , or that the vision system is subject to relatively fewer errors in identifying the location and orientation of those bundles  201 . 
     In one embodiment, the palletizer control system  160  can pick up the bundles  201  from the conveyor  130 . For example, as described herein, the palletizer control system  160  can include one or more robotic arms (not shown) that can grip one or more bundles  201  and lift them from the conveyor  130 . The one or more robotic arms can each include a grabbing apparatus, such as a fork or a friction gripper, that can seize each bundle  201  in turn and remove that bundle  201  from the conveyor  130 . The one or more robotic arms can each include a lifting apparatus, such as a hydraulic arm that can raise or lower the bundles  201 , such as once they are gripped, and move them upward from the conveyor  130 . The one or more robotic arms can each include a rotating or translating apparatus that can move the bundles  201  from the conveyor  130 , such as once they are lifted from the conveyor  130 , to another location. 
     In one embodiment, the palletizer control system  160  can place the bundles  201  in the tier build area  220 . For example, the palletizer control system  160  can use the one or more robotic arms to stack the bundles  201  in one or more patterns, each pattern forming a layer or tier, such as described with respect to  FIG. 3 . In some examples, the palletizer control system  160  can use the one or more robotic arms to stack the bundles  201  in parallel, such as seizing more than one such bundle  201  from the conveyor  130  and moving the more than one such bundle  201  into the layer or tier concurrently. 
     In a first set of alternative examples, the palletizer control system  160  can use the one or more robotic arms to stack the bundles  201  in sequence. For a first example, the robotic arms can seize one such bundle  201  at a time from the conveyor  130  and move that one such bundle  201  in its turn into the layer or tier. For a second example, the robotic arms can seize both a first and second such bundle  201  from the conveyor  130 . In such second examples, the robotic arms can seize a first bundle  201 , lift it, seize a second bundle  201 , position the first bundle  201  above the second bundle  201 , and move the first and second bundle  201  together to the layer or tier. In other examples, the robotic arms can pick up two or more bundles side-by-side, perhaps with a support such as a shelf under one more of the bundles. 
     In a second set of alternative examples, the palletizer control system  160  can use the one or more robotic arms to stack the bundles  201  either in parallel or sequence, depending on circumstances. For example, the palletizer control system  160  can be responsive to one or more of the following. (A) The palletizer control system  160  can decide to act in parallel or sequence in response to the space between bundles  201 . (B) The palletizer control system  160  can decide to act in parallel or sequence in response to the timing between arrival of bundles  201 . (C) The palletizer control system  160  can decide to act in parallel or sequence in response to the number of spaces for such bundles  201  available in each layer or tier. (D) The palletizer control system  160  can decide to act in parallel or sequence in response to some combination or conjunction of factors, or in response to other factors. 
     LAYERS, TIERS, AND STACKS. In one embodiment, the tier build area  220  can include a first tier conveyor that, upon completion of a stack of layers or tiers, moves the stack of layers or tiers into the tier squaring area  230 . The tier squaring area  230  can include a region that allows devices or structure to cause each stack of layers or tiers to be “squared up.” This can have the effect of causing each stack of layers or tiers to have a relatively well-ordered set of bundled, each relatively well-positioned with respect to a center of gravity, and each having a relatively smooth set of edges or sides. In such cases in which each bundle  201  includes sheets of corrugated cardboard material, or includes a stack of other relatively flat sheets of material (such as metal, plastic, or thin wood), this can have the effect of smoothing the sides of each stack to prevent excess material, ridges, or other protrusions that might cause one or more individual sheets to be damaged by other processes. 
     In one embodiment, the tier squaring area  230  can be coupled to a tie sheet hopper  231 . The tie sheet hopper  231  can maintain and dispense tie sheets (not shown) that can be placed under each stack before that stack is squared up and tied. This can have the effect that the bottom of each stack (such as the bottom layer or tier, or the bottom sheet) is protected against foreign object damage, protected against damage from components of one or more conveyors, or otherwise. 
     In one embodiment, the tier squaring area  230  can include an (optional) tier center divider  232 , or other separator devices or structures, or other collating or collecting devices or structures. This can have the effect that the tier squaring area  220  can provide separation of stacks into substacks, or collection of stacks into superstacks, some combination or conjunction thereof, or otherwise. 
     In one embodiment, the tier squaring area  230  can include second tier conveyor that, upon tying of a stack, can move the stack onto the stack build area  250 . The stack build area  250  can include a region that allows multiple stacks to be collected, such as for dispensing onto one or more pallets that can transport the stacks out of the production area. For example, completed stacks can be transported out of the production area and toward a loading region, where the stacks can be loaded onto transportation. Tiers can be built as part stacks, or tiers can be built and then moved or assembled into stacks. 
     In one embodiment, the stack build area  250  can be coupled to a stack exit conveyor  251  that can move stacks from the stack build area  250  to a location from which those stacks can be transported. For example, stacks can be transported from the stack exit conveyor  251  using one or more forklifts or other equipment. 
     In one embodiment, the stack build area  250  can be coupled to a bottom sheet conveyor  252  that can move bottom sheets under each stack before that stack is transported. Alternatively, in one embodiment the invention can be used to dispense pallets, and in another embodiment, pallets with bottom sheets could be dispensed. This can have the effect that the bottom of each stack (such as the bottom layer or tier, or the bottom sheet) is protected against foreign object damage, protected against damage from components of one or more conveyors, or otherwise. The bottom sheet conveyor  252  can be coupled to a bottom sheet hopper  253  that can maintain and dispense those bottom sheets, with the effect that the bottom sheet conveyor  252  can move one or more bottom sheets to the stack build area  250  before each stack is built in the stack build area  250 . 
     As further described with respect to  FIG. 3 , the method of layering or tiering can operate in conjunction with receipt of incoming bundles  201  on the conveyor  130 , and separately from squaring-up of layers or tiers by devices or structures downstream from the conveyor  130  and the bundle pick area  210 . This has the effect that the conveyor  130  and the robot  110  can operate at a first speed, optimized to pick up bundles  201  from the conveyor  130  and place them into the tier squaring area  230 . Similarly, this has the effect that the tier squaring area  230 , and accompanying squaring-up elements, can operate at a second speed, optimized to square up layers or tiers after bundles  201  have been placed in them. 
     For example, if bundles  201  arrive on the conveyor  130  at a certain speed, the robot  110  can move those bundles  201  from the bundle pick area  210  at that speed (or faster). While those bundles  201  are being moved, devices in the tier squaring area  230  can be operating to square up layers or tiers. Moving bundles  201  from the bundle pick area  210  does not have to wait for the squaring-up operation. This can provide an improvement in speed over performing the operation of moving bundles  201  and squaring-up layers or tiers with the same devices or in the same area. 
     Example Method of Palletizing 
       FIG. 3-1 through 3-52  (collectively referred to as  FIG. 3 ) show a conceptual drawing of a method of layering or tiering. 
     A method of using an example system is described herein. In one embodiment, the method steps can be performed in an order as described herein. However, in the context of the invention, there is no particular requirement for any such limitation. For example, the method steps can be performed in another order, in a parallel or pipelined manner, or otherwise. For another example, while this example discusses building a tier and then sending the tier to a squaring area, the bundle could be sent to a squaring unit and the tier constructed at or near the squaring unit. 
     In this description, where the “method” is said to arrive at a state or perform an action, that state is arrived at, or that action is performed, by one or more machines associated with performing the method. In one embodiment, the method can be performed, at least in part, by a control device separate from the machines in the production line. In alternative embodiments, the method  300  can be performed by one or more machines in a production system. For example, one or more such machines can operate in conjunction or cooperation, or each performing one or more parts of the method. 
     Similarly, although one or more actions can be described herein as being performed by a single device, in the context of the invention, there is no particular requirement for any such limitation. For example, the one or more devices can include a cluster of devices, not necessarily all similar, by which actions are performed. Also, while this application generally describes one or more method steps as distinct, in the context of the invention, there is no particular requirement for any such limitation. For example, the one or more method steps could include common operations, or could even include substantially the same operations. 
     Although the operation of the method is generally shown in  FIG. 3  looking from the top down, no limitation should be read into the method or the invention due to this form of description. 
     METHOD BEGINS. In one embodiment, at a state 0.0 shown in  FIG. 3-1 , the robot  110  is holding an incoming bundle (a “first bundle”)  201 , while a tier  320  is conveyed away from the tier build area  220  by the first tier conveyor  170  into the tier squaring area  230 . For example, the tier  320  can include a set of arranged bundles  201  in designated locations  330   a ,  330   b ,  330   c , and  330   d . In such examples, the set of arranged bundles  201  can have been placed in those designated locations by the robot  110 , using one or more bundles  201  that arrived earlier. 
     In one embodiment, the tier squaring area  230  can be disposed, as described above, to square up the tier  320 . For example, the tier  320  can be nudged against a barrier, or a squaring element can be nudged against a portion of the tier  320 , with the effect that objects in the tier  320  can be arranged into a shape that has relatively straight sides and does not have any extrusions. 
     In one embodiment, the robot  110  can include a pair of grippers  310   a ,  310   b , coupled to a holding device  310   c , and coupled to a lifting element  310   d . For a first example, the grippers  310   a ,  310   b  might operate by inserting tongs underneath the bundles  201 . For a second example, the lifting element  310   d  might include a hydraulic lift coupled to a crane or other relatively static holding element. 
     FIRST BUNDLE. In one embodiment, at a sequence of states 0.2 through 1.0, shown in  FIG. 3-2  through  FIG. 3-6 , the robot  110  moves the first bundle  201  into a first position in the tier build area  220 . For example, the robot  110  can pick up or otherwise grip the first bundle  201  and move the bundle  201  to a first designated location  330   a.    
     In one embodiment, at a state 1.0 shown in  FIG. 3-6 , the robot  110  releases the first bundle  201  at the first designated location  330   a , such as by releasing the grippers  310   a ,  310   b.    
     In one embodiment, at a state 1.2 shown in  FIG. 3-7  and a state 1.4 shown in  FIG. 3-8 , the robot  110  disengages from the first bundle  201 , such as by raising itself above a highest element of the first bundle  201 . 
     SECOND BUNDLE. In one embodiment, at sequence of states 1.6 through 2.4 shown in  FIG. 3-9  through  FIG. 3-13 , the robot  110  moves to a location and orientation of a second incoming bundle  201 . 
     In one embodiment, at a state 2.6 shown in  FIG. 3-14  and a state 2.8 shown in  FIG. 3-15 , the robot  110  grips the second incoming bundle  201 , while the tier  320  can remain stable in the tier build area  220 . 
     In one embodiment, at a sequence of states 3.0 through 4.0 shown in  FIG. 3-16  through  FIG. 3-21 , the robot  110  moves the second incoming bundle  201  into a second position in the tier build area  220 . For example, the robot  110  can pick up or otherwise grip the second bundle  201  and move the second bundle  201  to a second designated location  330   b.    
     In one embodiment, at a state 4.2 shown in  FIG. 3-22  and a state 4.4 shown in  FIG. 3-23 , the robot  110  similarly releases the second bundle  201  at the second designated location  330   b , such as by releasing the grippers  310   a ,  310   b.    
     In one embodiment, at a state 4.6 shown in  FIG. 3-24 , the robot  110  similarly disengages from the second bundle  201 , such as by raising itself above a highest element of the second bundle  201 . 
     THIRD BUNDLE. In one embodiment, at a sequence of states 4.8 through 5.8 shown in  FIG. 3-25  through  FIG. 3-30 , the robot  110  similarly moves to a location and orientation of a third incoming bundle  201 . For example, the tier  320  can be moved by the tier build conveyer  170  while the robot  110  is moving and the third bundle  201  remains stable in the bundle pick area  210 . 
     In one embodiment, at a state 6.0 shown in  FIG. 3-31  and a state 6.2 shown in  FIG. 3-32 , the robot  110  grips the third incoming bundle  201 , while the tier  320  remains stable in the tier build area  220 . 
     In one embodiment, at a sequence of states 6.4 through 7.2 shown in  FIG. 3-33 through 3-37 , the robot  110  moves the third incoming bundle  201  into a third position in the tier build area  220 . For example, the robot  110  can pick up or otherwise grip the third bundle  201  and move the third bundle  201  to a third designated location  330   c.    
     In one embodiment, at a state 7.2 shown in  FIG. 3-37  and a state 7.4 shown in  FIG. 3-38 , the robot  110  similarly releases the third bundle  201  at the third designated location  330   c , such as by releasing the grippers  310   a ,  310   b.    
     In one embodiment, at a state 7.6 shown in  FIG. 3-39 , the robot  110  similarly disengages from the third bundle  201 , such as by raising itself above a highest element of the third bundle  201 . 
     FOURTH BUNDLE. In one embodiment, at a sequence of states 7.8 through 8.6 shown in  FIG. 3-40  through  FIG. 3-44 , the robot  110  similarly moves to a location and orientation of a fourth incoming bundle  201 . For example, the tier  320  can remain stable in the tier build area  220  while the robot  110  is moving. 
     In one embodiment, at a state 8.8 shown in  FIG. 3-45  and a state 9.0 shown in  FIG. 3-46 , the robot  110  grips the fourth incoming bundle  201 , while the tier  320  remains stable in the tier build area  220 . 
     In one embodiment, at a sequence of states 9.0 through 9.8 shown in  FIG. 3-46 through 3-50 , the robot  110  moves the fourth incoming bundle  201  into a fourth position in the tier build area  220 . For example, the robot  110  can pick up or otherwise grip the fourth bundle  201  and move the fourth bundle  201  to a fourth designated location  330   d.    
     In one embodiment, at a state 10.0 shown in  FIG. 3-51  and a state 10.2 shown in  FIG. 3-52 , the robot  110  similarly releases the fourth bundle  201  at the fourth designated location  330   c , such as by releasing the grippers  310   a ,  310   b.    
     In one embodiment, at a state 10.2 shown in  FIG. 3-52 , the robot  110  similarly disengages from the fourth bundle  201 , such as by raising itself above a highest element of the fourth bundle  201 . 
     METHOD ENDS AND REPEATS. In one embodiment, the method repeats so long as there are further incoming bundles  201 . 
     LAYER FORMATION IN THE TIER BUILD AREA. In another embodiment, the system is configured to form bundle layers in the tier build area  220 . In this embodiment, the robot  110  forms a multi-layered tier  320  of bundles  201  by stacking two or more layers of bundles  201  on top of each other in the tier build area  220 . Once the robot  110  builds up a desired number of layers, the multi-layered tier  320  may be moved out of the tier build area  220  and into the tier squaring area  230 . In one embodiment, two or more multi-layered tier  320  of bundles  201  may be gathered together and combined into a completed stack in the stack build area  250 . 
     Turning now to specific methods of building a multi-layered tier  320  in the in the tier build area  220 , reference is again made to  FIG. 3 . In one implementation, the robot  110  stacks bundles  201  to a desired height in a particular designated location before the robot  110  moves onto stacking in the next designated location. For example, in connection with building a two-layered tier  320  of bundles  201  in the tier build area  220 , the robot  110  may begin by stacking a first and a second bundle  201  on top of each other in the first designated location  330   a . Stacking the first and second bundle may include executing and then repeating the sequence of states 0.2 through 1.4, shown in  FIG. 3-2  through  FIG. 3-8 . The robot  110  then stacks a third and a fourth bundle  201  on top of each other in the second designated location  330   b  by, for example, executing and then repeating the sequence of states 1.6 through 4.6 shown in  FIG. 3-9  through  FIG. 3-24 . Following this, the robot  110  stacks a fifth and a sixth bundle  201  on top of each other in the third designated location  330   c  by, for example, executing and then repeating the sequence of states 4.8 through 7.6 shown in  FIG. 3-25  through  FIG. 3-39 . Here, the two-layered tier  320  of bundles  201  can be moved by the tier build conveyer  170  while the robot  110  is moving and the fifth bundle  201  remains stable in the bundle pick area  210 . Finally, the robot  110  stacks a seventh and an eighth bundle  201  on top of each other in the fourth designated location  330   d  by, for example, executing and then repeating the sequence of states 7.8 through 10.2 shown in  FIG. 3-40  through  FIG. 3-52 . 
     In another implementation, the robot  110  stacks bundles  201  to a desired height in the first and second designated locations  330   a - b  before the robot  110  moves onto stacking in the third and fourth designated locations  330   c - d . For example, in connection with building a two-layered tier  320  of bundles  201  in the tier build area  220 , the robot  110  may begin by placing a first bundle  201  in the first designated location  330   a  and a second bundle  201  in the second designated location  330   b . Placing the first and second bundles may include executing the sequence of states 0.2 through 4.6, shown in  FIG. 3-2  through  FIG. 3-24 . The robot  110  then stacks a third bundle  201  on top of the first bundle  201  in the first designated area  330   a  and a fourth bundle  201  on top of the second bundle  201  in the second designated area  330   b  by, for example, executing a second time the sequence of states 0.2 through 4.6, shown in  FIG. 3-2  through  FIG. 3-24 . Following this, the robot  110  places a fifth bundle  201  in the third designated location  330   c  and a sixth bundle  201  in the fourth designated location  330   d  by, for example, executing the sequence of states 4.8 through 10.2, shown in  FIG. 3-25  through  FIG. 3-52 . Here, the two-layered tier  320  of bundles  201  can be moved by the tier build conveyer  170  while the robot  110  is moving and the fifth bundle  201  remains stable in the bundle pick area  210 . Finally, the robot  110  stacks a seventh bundle  201  on top of the fifth bundle  201  in the third designated area  330   c  and an eighth bundle  201  on top of the sixth bundle  201  in the fourth designated area  330   d  by, for example, executing a second time the sequence of states 4.8 through 10.2, shown in  FIG. 3-25  through  FIG. 3-52 . 
     In still another implementation, the robot  110  is configured to place bundles  201  on the far side of the tier build area  220  such that the intermediate operation of the tier build conveyer  170  moving a partially completed tier  320  may be omitted. Thus, in one respect, the robot  110  may be configured to place bundles  201  in the first designated locations  404   a - d  shown in  FIG. 4-1 . In another respect, the robot  110  may be configured to place bundles  102  in the second designated locations  408   a - d  shown in  FIG. 4-2 . As can be seen, the first designated locations  404   a - d  do not overlap with or are otherwise offset from the second designated locations  408   a - d . More specifically, the second designated locations  408   a - d  are shifted 90 degrees about a central axis with respect to the positions of the first designated locations  404   a - d . In one embodiment, the robot  110  builds a multi-layered tier of bundles  201  by alternating between the first designated locations  404   a - d  and the second designated locations  408   a - d . For example, in connection with building a two-layered tier  320  of bundles  201  in the tier build area  220 , the robot  110  may build a first layer by placing a bundle  201  in each of the four designated locations  404   a - d  shown in  FIG. 4-1 . Following this, the robot  110  may build a second layer on top of the first layer by placing a bundle  201  in each of the four designated locations  408   a - d  shown in  FIG. 4-2 . Due to the offset between the first designated locations  404   a - d  and the second designated locations  408   a - d , each bundle in the second layer is placed on a portion of more than one bundle in the first layer. 
     The multilayered tier formation methods are discussed in connection with two layered tiers by way of example and not limitation. It should be appreciated that the tier  320  may be built to any desired height prior to tier  320  being moved out of the tier build area  220 . Thus, in one embodiment, the tier  320  may be moved out of the tier build area  220  once the second layer is in place. In other embodiments, additional layers are added to the tier  320  before the tier is moved out of the tier build area  220 . By way illustration,  FIG. 5  shows perspective view of a six-layered tier  500  built in the tier build area  220 . The six-layered tier  500  is built using the method discussed above that alternates between the designated locations  404   a - d  shown in the  FIG. 4-1  and the designated locations  408   a - d  shown in the  FIG. 4-2 . The six-layered tier  500  shown in  FIG. 5  illustrates the pattern of bundles that is created by the offset between the first designated locations  404   a - d  and the second designated locations  408   a - d . For example, a second layer bundle  504  is placed on top of a portion of two first layer bundles  508 . This orientation of bundles may provide stability to a multilayered tier. 
     While this method of operation has been primarily described with respect to bundles in the production line, in the context of the invention, there is no particular requirement for any such limitation. For example, methods of operation can be performed with respect to individual objects, or sets of objects, or other elements that might arrive and for which it is desirable to move and organize those elements. 
     Similarly, while this method of operation has been primarily described with respect to one robotic device and one production line, in the context of the invention, there is no particular requirement for any such limitation. For example, methods of operation can be performed with respect to multiple robotic devices, multiple production lines, multiple controllers, multiple types of layers or tiers. Moreover, methods of operation can be performed with respect to crossover between or among multiple robotic devices, multiple production lines, multiple controllers, multiple types of layers or tiers. 
     Alternative Embodiments. 
     After reading this application, those skilled in the art would recognize many of the advantages of this description, and would recognize that various changes may be made in the form, construction, and arrangement of the components without departing from the scope or spirit of the subject matter or without sacrificing its advantages. Those embodiments described herein are merely explanatory and illustrative. While the present disclosure has been described with reference to various embodiments, it will be understood that these embodiments are illustrative and that the scope of the disclosure is not limited to them. Many variations, modifications, additions, and improvements are possible. More generally, embodiments in accordance with the present disclosure have been described in the context of particular embodiments. Functionality may be separated or combined in procedures differently in various embodiments of the disclosure or described with different terminology. These and other variations, modifications, additions, and improvements may fall within the scope of the disclosure as defined in the claims that follow. 
     Aspects of the embodiments described herein could be provided as a computer program product, such as may include a computer-readable storage medium or a non-transitory machine-readable medium maintaining instructions interpretable by a computer or other electronic device, such as to perform one or more processes. A non-transitory machine-readable medium includes any mechanism for storing information in a form (including a processing application or software) readable or interpretable by a machine (such as a computer). The non-transitory machine-readable medium may take the form of, but is not limited to, any known storage technique, including magnetic storage media, optical storage media, magneto-optical storage media; read only memory (ROM); random access memory (RAM); erasable programmable memory (including EPROM and EEPROM); flash memory; and otherwise.