Patent Description:
Conventional materials handling facilities typically utilize a series of conveyor belts which deliver generic totes or receptacles from one specific location to another within the material handling facility. These conveyor belts are usually operated in an "always on" mode, in which they are constantly moving, even if no receptacles are being moved. Keeping these conveyors constantly moving can require a significant allocation of energy, as the conveyor belts themselves are often very heavy. In addition, such systems are inherently very noisy due to the constant movement of the conveyors, and all of the moving parts can require frequent maintenance and generate large amounts of dust and dirt, which can reduce the reliability of such systems.

<CIT> relates to a control system for a tilt tray sorter. <CIT> relates to a carrying apparatus having a carrier levitated by a magnetic force.

Particular aspects are set out in the dependent claims.

The present disclosure, as set forth below, is directed to various embodiments of methods and apparatus for transporting portable receptacles utilizing linear induction motor-driven materials handling systems. Linear induction motors ("LIMs") are used as a mechanism for transporting individual portable receptacles from a first location to a second location within the given materials handling system. In other examples, a single LIM may be utilized to move multiple portable receptacles from a first location to a second location in the system, whereby the LIM causes a first portable receptacle to begin moving and the electromagnetic force generated by the LIM is strong enough to move a series of receptacles located adjacent to each other within the system. In at least some embodiments, the LIMs are sized and configured such that the portable receptacles are at least partially levitated to reduce the force needed to drive the receptacles within the system by reducing the frictional force between the portable receptacles and the surface on which they move. In at least some other embodiments, individual portable receptacles can be moved from any one of many given starting positions to any one of many given intermediate positions and/or end positions. At some of those intermediate positions, for example, additional items made be added to the receptacle in order to build the order before it is packaged for shipment. In this manner, for example, a given portable receptacle might be utilized to accumulate multiple items in a given consumer's order, rather than simply being utilized to a transport a given item within the system.

A materials handling system includes one or more guide tracks to guide the portable receptacles. Each guide track includes a receiving surface that includes one or more LIMs and one or more side walls capable of guiding the portable receptacles and/or limit the movement of the portable receptacles such that the portable receptacles stay within the confines of the materials handling system. In some embodiments, the direction in which a given portable receptacle is traveling may be altered via the intervention of a physical device, such as a guide arm operable via a switch to redirect the receptacle from a given path toward point A to a given path toward point B. In at least some other embodiments, the direction in which a portable receptacle is moving is altered via one or more LIMs oriented such that the one or more LIMs alter the trajectory of the portable receptacle from a first path to a second path.

While many embodiments described herein relate to materials handling system and the various ways that such systems utilize LIMs to move portable receptacles to different locations within a materials handling system, at least some examples are directed to the portable receptacle itself. In many instances, portable receptacles are, by their nature, light-weight, but sturdy devices that can be used to transport one or more items ranging in weight from very light (e.g., less than <NUM> ounces) to very heavy (e.g., greater than <NUM> pounds). Accordingly, portable receptacles may be manufactured from one or more non-conductive materials including, but not limited to, various plastics (e.g., polyethylene terephthalate ("PET"), polypropylene, polystyrene, etc.), rigid rubber, and/or cardboard, and combinations thereof. Such non-conductive materials are capable of providing the necessary rigidity and strength for the portable receptacle while maintaining the light-weight form factor needed to facilitate movement of the portable receptacles throughout the materials handling system.

However, while portable receptacles made of such non-conductive materials are suitable for most materials handling systems operating using standard conveyer belts and pulley systems, these receptacles are not capable of interacting with a materials handling system including one or more LIMs as mechanisms to move the portable receptacles from one location to another within the materials handling system, such that the portable receptacles themselves are part of the driving motor. For example, in conventional LIM-based systems, the LIM carriers (i.e., the stator portion of the linear motor) are designed to hold the receptacles securely in place while the carriers transport the receptacles about the system. In accordance with examples described below, the portable receptacles are modified to include conductive materials such that the receptacles themselves take the place of conventional LIM carriers and are therefore an integral part of the linear motors that are used to move the receptacles about the system, which can greatly reduce the number of moving parts required in these systems. In some examples, portable receptacles may be made solely of conductive materials (e.g., iron, copper, etc.). However, creating portable receptacles solely out of conductive materials may be costly, and may create receptacles that are too heavy or cumbersome to move efficiently within the materials handling system.

According to the invention, the portable receptacles are modified or redesigned such that at least a portion of the portable receptacle includes a conductive element that can interact with the LIMs in the materials handling system, while the remaining portions of the portable receptacle include one or more non-conductive materials. These conductive materials may be attached to the inner or outer surface of the receptacles, or they may be embedded within the non-conductive portion of the receptacles during the manufacturing of the receptacles. In other examples, the material used to manufacture the receptacles may be doped with an appropriate amount of conductive material such that the receptacles are produced in a manner that they can reliably interact with the LIMs in the material handling system. For example, the portable receptacles can, for example, be manufactured with a portion of conductive material located in a bottom portion of the receptacles, or the bottom portion of the receptacle can be impregnated with multiple individual conductive portions, such as conductive strips that may be utilized to assist in transporting and/or changing the direction of a given receptacle in the system. Alternately, some or all of the portable receptacles may be formed of a non-conductive material that is doped with one or more conductive elements or particles, for example, as part of an injection-molding process (this may be accomplished, for example by utilizing the doped material when forming the bottom of the receptacle and non-doped material when forming the side walls to keep the receptacles as light and inexpensive as possible).

Embodiments described below include materials handling systems that utilize one or more LIMs to facilitate movement of portable receptacles that are at least partially conductive, such that the receptacles themselves form part of the driving inductive motor. In this manner, the materials handling systems utilize less energy because only the driving LIMs need to be active, and they generate less noise and dirt due to the significant reduction in moving parts in the transport system itself. Further, the reduction in moving parts may reduce the need for frequent or periodic maintenance of such moving parts. In addition, the reduced amount of friction between the portable receptacle and guide track allows for the portable receptacles to travel substantially unimpeded and with great efficiency. In some embodiments, the electromagnetic forces between the LIMs and the conductive elements of the portable receptacles enable the portable receptacles to levitate above the guide track, thereby substantially removing any frictional forces. Another beneficial aspect of such materials handling systems is that the amount of energy needed to operate the one or more LIMs is much less than for a typical conveyance system as only enough energy is needed to "push" one receptacle from one LIM to a next LIM. A further advantage of such materials handling systems is that the systems are substantially deterministic, such that the position of each portable receptacle should be capable of being calculated beforehand, regardless of the weight of the receptacle or of any item placed therein.

<FIG> shows an illustrative schematic view of material handling system <NUM>, which includes receiving surface <NUM>, linear induction motors ("LIMs") <NUM>, one or more sensors <NUM>, a network <NUM>, a data store <NUM>, and a control module <NUM>. System <NUM> may also include one or more user devices <NUM> that can be used to access, monitor and/or control various aspects of system <NUM>. Sensors <NUM> may include any number and variety of different sensors, depending on the application. For example, sensors <NUM> may, in some embodiments, be used to monitor the location and/or contents of receptacle <NUM> as it travels about materials handling system <NUM>, and this could be accomplished in a number of different ways, such as through the use of RFID tags attached to receptacle <NUM> or items contained therein, in which case sensors <NUM> would be RFID readers. Alternately, an identifier, e.g., a sticker, could be placed on each receptacle <NUM> or item contained therein that can include a QR or bar code, in which case sensors <NUM> would be a corresponding scanner/reader. Other embodiments can include imaging sensors, thermal sensors, photographic imaging devices, etc. Still other embodiments may include sensors that can measure the weight of receptacle <NUM>, which could be used to verify that certain selected items have been placed therein (in which case the individual weight of such items would be known).

As indicated above, system <NUM> may also include one or more user devices <NUM> that can be used by employees working with system <NUM> to fulfill customer orders. In some embodiments, user devices <NUM> could be any one of a number of smartphones, running a dedicated "app" that could interface with system <NUM> via a Bluetooth or WiFi connection (through communications module <NUM> in control module <NUM>). Alternatively, user devices <NUM> could be tablet computers that could also be configured to run a dedicated app and be connected to system <NUM> via a Bluetooth or WiFi connection. In addition, user devices <NUM> could instead be dedicated hand held devices that are designed specifically to be used with system <NUM> to enable a user, for example, to monitor the status: of system <NUM>, of individual receptacles <NUM>, and/or of individual customer orders, etc. In some embodiments, for example, user devices <NUM> could be utilized by employees working at individual workstations (see, for example, the description below related to workstation <NUM>) at which receptacles <NUM> stop in order to be filled with one or more items. The employee could utilize user device <NUM> to inform system <NUM> when the designated task for that individual workstation has been completed so that system <NUM> could continue transporting a given receptacle <NUM> through the remainder of its path until all of the items designated for that given receptacle have been loaded therein and the given receptacle has been moved to the appropriate location for packaging and shipping of those items.

While system <NUM> may be configured to include hard-wired interconnections between individual electronic components, such as LIMs <NUM> and control module <NUM>, more benefits may be obtained when network <NUM> is utilized for electronic communications, such as is illustrated in <FIG>, where each LIM <NUM>, sensor <NUM>, data store <NUM>, user device <NUM>, and control module <NUM> are all coupled together via network <NUM>. The connections to network <NUM> may be physical, such as via an Ethernet connection, or they may be wireless, such as via a Bluetooth and even cellular connection (and system <NUM> may include any combination of such connections, as appropriate). Materials handling system <NUM> is configured to transport portable receptacles <NUM> from at least one location to at least one other location through the application of electromagnetic forces that are established between LIMs <NUM> and a conductive portion of receptacles <NUM>, such that the receptacles form part of the driving induction motor. In particular, LIMs <NUM>, as briefly described above and shown in the figures, are essentially just a portion of the actual linear induction motor, while the conductive portion of receptacles <NUM> form the remaining portion of the linear induction motor. As is described in more detail below, the LIM <NUM> is used to create the magnetic field that interacts with the conductive portion of receptacles <NUM>.

Control module <NUM> may include a variety of different modules, such as processor(s) <NUM>, memory <NUM> (such as conventional random access memory "RAM"), data storage <NUM> (which may include storage such as hard drives, FLASH drives and the like), communications circuitry <NUM> (such as, for example, Ethernet, Bluetooth and cellular interface circuitry), sensor receiver modules <NUM> (which may include circuitry to monitor signals from one or more of sensors <NUM>), and signal generation module <NUM> (which may, for example, include circuitry to generate signals to drive and control LIMs <NUM>, such as pulse width modulation signals as will be described in more detail below).

Processor(s) <NUM> may include, for example, one or more individual microprocessors which can be configured to work independently or in conjunction with each other (such as in a distributed processing system), and the individual processors may be single-core or multi-core configurations. Processor(s) <NUM> can be coupled within control module <NUM> to each of memory <NUM> (which itself may include random access memory or "RAM", read only memory or "ROM," etc., which is used to store various portions of information for use by processor(s) <NUM>), storage <NUM> (which may include conventional hard drives, FLASH memory devices, hybrid devices, cloud storage, etc., that can all be used to store programs, applications, data, etc. for use by processor(s) <NUM>), communications module <NUM>, sensor module <NUM> and signal generation module <NUM>. Communications module <NUM> can include, for example, the necessary interface to control incoming and outgoing communications through Bluetooth devices, Wi-Fi connections, cellular phone service connections, etc., as well as providing the basic interface for Ethernet communications that can be used to connect control module <NUM> to network <NUM>. Sensor module <NUM> can provide, for example, control signals that may be used to activate and monitor sensors <NUM> throughout system <NUM>, and it may also be utilized to receive sensed signals and provide the received signals to processor(s) <NUM> such that processor(s) <NUM> may analyze the received signals and generate an accurate representation of the status of system <NUM>. Signal generation module <NUM> may be coupled to processor(s) <NUM> such that processor(s) <NUM> can instruct signal generation module <NUM> what type of driving signals to generate for a specific LIM, and to provide the activation signals to signal generation module <NUM> that can cause the generated driving signals to be provided to a specific LIM <NUM>.

System <NUM> also may include data store <NUM> that can be utilized for a variety of purposes, such as to store the status and location of individual customer orders, to send inventory requests to control module <NUM> that may then initiate the instructions to fulfill consumer orders, to store inventory control information such as bar codes for individual items, to store information regarding each individual portable receptacle in system <NUM>, and other information as may be appropriate. Additional information that may be included in data store <NUM> can include properties or characteristics, such as approximate weights, of items that may be deposited within receptacles <NUM>, individual information concerning LIMs <NUM>, such as LIM identifiers and LIM locations, as well as the locations and processing capabilities of workstations within system <NUM>.

Receiving surface <NUM> may be formed from a variety of materials. For example, surface <NUM> may be formed from aluminum (which may or may not be polished), stainless steel, or any number of other metals or plastics. Any of these materials may be selected in order to attempt to lower the surface friction between surface <NUM> and the portion of receptacle <NUM> that makes contact with surface <NUM> (various different configurations of receptacle <NUM> are described below, which persons skilled in the art will appreciate are intended to be illustrative and not limiting). In addition, these materials may be coated with any number of substances in order to further reduce the surface friction, such as a coating of Teflon or silicon-based material. In other embodiments, surface <NUM> may include a number of small holes that could be formed from drill or laser, through which compressed air may be applied to cause receptacles <NUM> to float through system <NUM> (using principles that are similar to those used in designing an air hockey table). In general, the lower the surface friction, the less force required to be generated by LIMs <NUM> in order to propel receptacles <NUM> along (and therefore, less energy is required to keep system <NUM> running).

Surface <NUM> may also, for example, be formed of non-continuous materials, such as a series of rollers which rotate in a highly efficient manner through the use of internal ball bearings. Moreover, surface <NUM> may be a wide-open, free-form surface, such that receptacles could be propelled in any direction based on the configuration of LIMs <NUM>, or surface <NUM> may be combined with rails <NUM> (see <FIG> described below) to provide a higher degree of reliability that receptacles will travel along their intended path. The use of rails <NUM>, however, may limit the different paths that receptacles <NUM> can be propelled (for example, as described in more detail below with respect to <FIG>, if rails <NUM> are not utilized, receptacles <NUM> can be propelled along a direction Q such that the receptacles <NUM> cross path X). Moreover, while the figures show surface <NUM> as generally a solid surface, surface <NUM> may instead be formed as a pair of rails or individual surfaces on which the outer edges of receptacles <NUM> would travel (the rails, for example, could be formed from PVC tubes or other similar implementations). In that case, LIMs <NUM> could be mounted on individual, free-standing columns located in between the two portions that make up surface <NUM>, such that there would be no surfaces, components or structures between LIM <NUM> and receptacle <NUM> as receptacle <NUM> passes over LIM <NUM>. In these instances, the surface friction between surface <NUM> and receptacle <NUM> would be reduced simply because there would be fewer points of contact between them.

<FIG> shows a schematic top view of a portion of materials handling system <NUM>. As shown in <FIG>, materials handling system <NUM> may include a receiving surface <NUM>, one or more guides <NUM> and one or more LIMs <NUM> that are used to control the movement of portable receptacles <NUM> through system <NUM> from a first position to a second position, and subsequently to a third position, fourth position, and/or nth position as needed. For example, at a first position, a portable receptacle may receive a first item, and then be moved to a second position where the receptacle may receive a second item and/or have the first item removed.

Receiving surface <NUM> corresponds to a surface upon which the one or more portable receptacles <NUM> move (or, as described above, surface <NUM> may be implemented as a pair of rails or individual surfaces with LIMs <NUM> located between them). The various LIMs are operable to be located on receiving surface <NUM>, embedded within receiving surface <NUM>, positioned below receiving surface <NUM> (see, for example, <FIG> and the corresponding description below), and/or located between portions of surface <NUM>. As described above, in some embodiments, receiving surface <NUM> is operable to reduce the surface friction between the one or more portable receptacles moving thereon, such as through the use of a coating of silicon-based material, to reduce surface friction (other materials, for example, may be similarly utilized to minimize the surface friction between receptacles <NUM> and surface <NUM>). Various other mechanisms to reduce the amount of surface friction between receiving surface <NUM> and portable receptacles <NUM> may also include modifying the temperature of receiving surface <NUM>. Persons of ordinary skill in the art will recognize that any other suitable technique may be used to lower the surface friction between receiving surface <NUM> and portable receptacles <NUM>, and the aforementioned are merely exemplary.

Receiving surface <NUM>, in some embodiments, can be substantially planar and continuous, however, other configurations are also disclosed herein. For example, receiving surface <NUM> may be wider at one position and thinner at another position (see, for example, <FIG>). Further, receiving surface <NUM> may include one or more rails or tracks (for example, similar to train tracks), instead of a continuous, planar surface, upon which the receptacles <NUM> can move between locations of the system <NUM>. Receiving surface <NUM> may also be curved, both in the direction of motion of portable receptacles <NUM> and/or perpendicular to the direction of motion. For example, a center portion of receiving surface <NUM> may be raised in relation to a side portion of receiving surface <NUM>. Receiving surface <NUM> may also be oriented at any suitable angle with respect to gravity such that portable receptacles <NUM> are capable of being moved from a first height to a second height due to gravitational forces.

In some embodiments, materials handling system <NUM> may include one or more guides <NUM> that operate to keep receptacles <NUM> on receiving surface <NUM> while in motion. This may be especially useful in situations where malfunction of one or more LIMs can occur and portable receptacles <NUM> are unconstrained - protecting them from potentially falling off an edge of surface <NUM>. Guides <NUM> may be short rails along the sides of surface <NUM> (see, for example, <FIG>), or guides <NUM> may be complete side-sections of material (similar to the material that forms surface <NUM>), such that there is virtually little chance of any of receptacles <NUM> falling off of surface <NUM> regardless of the circumstances. It should be noted that it may also be possible to design system <NUM> such that the interaction between LIMs <NUM> and receptacles <NUM> is so tightly coupled or controlled that guides <NUM> may not be necessary when the system is provided with electricity. For example, LIMs <NUM> may be located close together along a direction of movement of the receptacles <NUM> on the receiving surface <NUM>, such that a moving receptacle <NUM> moves directly from one LIM <NUM> to another, with little to no free movement.

Accordingly, guides <NUM> may be designed in any suitable manner, depending on the application. For example, guides <NUM> may vary in height or shape along a length of receiving surface <NUM>, such that they may be straight, curved or any combination thereof. For example, guides <NUM> may be at a first height at a first section of receiving surface <NUM> which may be straight, and at a second height at a second section of receiving surface <NUM>, which itself may be curved. Thus, guides <NUM> may be substantially flat, curved, or any combination thereof.

In other embodiments, fewer LIMs may be utilized along a given portion of surface <NUM>, such as through the use of only LIMs <NUM> and <NUM> as shown in <FIG> (LIMs <NUM>, <NUM>, and <NUM> may be substantially identical to each other). As shown in <FIG>, LIMs <NUM> and <NUM> are spaced relatively farther apart from each other than any two adjacent LIMs <NUM> of the four LIMs <NUM>. Alternatively, LIMs <NUM> (and/or LIMs <NUM>, <NUM>), may actually be installed in system <NUM>, and any suitable operation may utilize each of LIMs <NUM> together or separately. For example, one particular operation may utilize only LIMs <NUM> and <NUM>, other operations may utilize LIMs <NUM> and <NUM>, and still other operations may utilize any combination of installed LIMs, such as LIMs <NUM>, <NUM> and <NUM>. In one embodiment, for example, when only LIMs <NUM> and <NUM> are utilized, the force applied to receptacles <NUM> may be such that a given receptacle <NUM> moves freely, or substantially freely, from LIM <NUM> to LIM <NUM>. Under such circumstances, a given receptacle <NUM> may be provided enough propulsion from the force applied by LIM <NUM> to reach LIM <NUM>, at which point LIM <NUM> may be capable of providing an additional force to receptacle <NUM> causing the receptacle to move to another position within materials handling system <NUM>.

In some embodiments, a first LIM, such as LIM <NUM>, may be capable of providing enough force to move multiple portable receptacles <NUM>. For example, a first portable receptacle 110A, a second portable receptacle 110B and a third portable receptacle 110C may be positioned adjacent to one another on receiving surface <NUM> between two LIMs, such as LIMs 106A and 106C (see <FIG>). A force applied to third portable receptacle 110C by LIM 106C is operable to move all three receptacles 110A, 110B, and 110C along receiving surface <NUM> toward LIM 106A, either electromagnetically or through a mechanical momentum transfer (e.g., elastic/inelastic collision). In this particular embodiment, multiple receptacles <NUM> are capable of being "pushed" along receiving surface <NUM> by a single LIM (e.g., LIM 106C), thereby further decreasing the amount of energy needed to operate materials handling system <NUM>.

Materials handling system <NUM> as shown in <FIG> may be a partial representation of an actual materials handling system that may be utilized to move items selected and ordered by a consumer from one or more given storage locations to one or more packing locations in order to prepare the ordered items for shipment to the consumer. In addition, materials handling system <NUM> may also be utilized to move the packed items located in the shipment boxes to one or more additional locations from which shipments may depart the materials handling system <NUM>.

<FIG> shows a schematic side view of materials handling system <NUM> which, as described above, includes receiving surface <NUM> and LIMs <NUM>. As shown in <FIG>, system <NUM> also includes lower surface <NUM> which may be located below receiving surface <NUM> by a given distance H. Distance H is set such that LIMs <NUM> are close enough to surface <NUM> such that they will be able to interact with the conductive elements of receptacles <NUM> moving across surface <NUM>. Lower surface <NUM> may be utilized for a variety of different reasons. In some embodiments, lower surface <NUM> may be implemented as a series of sliding drawers that provide easy access to LIMs <NUM> for maintenance and repair. Alternately, lower surface <NUM> might be implemented as a single sheet of material that is pre-populated with LIMs to simplify the fabrication process of system <NUM>. LIMs <NUM> may be installed in various other manners, such as those described below and shown in <FIG>. As shown in <FIG>, LIMs <NUM> may be located a common distance D apart from each other, or system <NUM> may be configured such that some LIMs <NUM> may be located a distance D apart from each other while others are either closer together or farther apart from each other depending on the desired results. For example, if surface <NUM> was configured as an incline, LIMs <NUM> may be located closer together so that the driving force from LIMs <NUM> is maintained as receptacles <NUM> move up the incline (see, for example, <FIG>).

<FIG> is a three dimensional illustration that shows the basic principles that are utilized in accordance with embodiments of the disclosure herein. In at least one embodiment, each of LIMs <NUM> is controlled by control module <NUM>, which is capable of sending one or more control signals (generated by signal generator <NUM>) to any LIM within system <NUM>. Those signals may include simple alternating currents (i.e., AC), or they may include more complicated signals, such as pulse-width modulated ("PWM") signals that can be used to provide more power to the LIMs in a more precisely controlled manner. Through the precise application of these signals, control module <NUM> is operable to keep receptacles <NUM> moving through materials handling system <NUM> in an orderly fashion in compliance with the operations of the materials handling system <NUM> (e.g., the ability to stop one or more receptacles <NUM>, change the direction of motion of receptacles <NUM>, etc.). While control module <NUM> is only shown being connected to LIMs <NUM> via network <NUM> in <FIG>, persons skilled in the art will appreciate control module <NUM> is coupled to communicate with LIMs <NUM> via network <NUM> in each of the other figures as well. For example, each of LIMs <NUM> may be individually addressable via network communications from control module <NUM>, which may select the appropriate LIMs to command based on information stored about the LIMs in data store <NUM>. Moreover, the communications between LIMs <NUM>, network <NUM> and control module <NUM> may be accomplished in a wide variety of ways, including any wired or wireless connections such as via Ethernet (typically a direct connection), Bluetooth and/or cellular service (typically accomplished via wireless connections). Alternately, LIMs <NUM> may be coupled to control module <NUM> via a direct, hard-wired connection.

Each of LIMs <NUM> operates in essentially the same manner regardless of which direction the electromagnetic force may be applied. When control module <NUM> sends a signal to a given LIM <NUM>, a current is generated in coils or wires within LIM <NUM>. The signal may be a simple AC signal, or it may be a more complex signal, such as a PWM signal, depending on the need. The generated current causes a magnetic field "B" to be generated perpendicular to receiving surface <NUM> (see <FIG>). The generated magnetic field B then induces a current "I" in conductive element <NUM> that is a part of receptacle <NUM>. Current I is generated parallel to surface <NUM>, but in a direction that is perpendicular to the intended axis of travel of receptacles <NUM>. The interaction between the generated magnetic field and the induced current, causes a force "F" to be applied to receptacle <NUM> that causes receptacle <NUM> to move in a direction "X. " The applied force needs to be, at a minimum, greater than the surface friction between receiving surface <NUM> and receptacles <NUM> in order to move the receptacles. Accordingly, during system operations, based on all of the known information, such as the contents of each receptacle <NUM>, the weight of the receptacle and contents, etc., control module <NUM> can generate varying signals to be applied to each individual LIM to dynamically control the movement, speed, stopping and starting of the LIMs as they travel throughout the materials handling system.

Persons skilled in the art will appreciate that, in accordance with the disclosures herein, the distance between receptacles <NUM> and LIMs <NUM>, which is indicated by reference "A" in <FIG>, is exaggerated for illustrative purposes only, and that the actual distance between LIMs <NUM> and receptacles <NUM> may be as small as a few millimeters in order to maximize the interaction between the generated field and the induced current. Persons skilled in the art will also appreciate that the interaction between LIMs <NUM> and conductive portion <NUM> may result in receptacles <NUM> being levitated at least a small portion above receiving surface <NUM>. The levitation may vary based on a number of factors, such as, for example, the number and weights of items located within a given receptacle <NUM>. Moreover, even if receptacle <NUM> is not actually levitated, it may be advantageous to apply the levitating force to reduce the surface friction between receiving surface <NUM> and receptacles <NUM>, which may reduce the energy needed to move receptacles <NUM> throughout system <NUM>.

Portable receptacles <NUM>, with the conductive material incorporated therein, operate as what is traditionally one half of a standard linear induction motor (that portion is sometimes referred to as a carrier or forcer). The other half of the linear induction motor, which is indicated throughout the disclosure as LIMs <NUM>, may include a series of magnets installed in alternating polarity (that portion is sometimes referred to as the magnetic rail or driver). The inclusion of conductive portion <NUM> within receptacles <NUM> results in receptacles <NUM> being a part of the induction motor itself. This provides improvements over conventional systems, such as the ability to energize only those portions of materials handling system <NUM> that are currently being used. For example, if system <NUM> were utilized to move a single receptacle <NUM> to three workstations in sequence for adding items from each work station, only the LIMs close to the current path of travel need be energized (for example, if the current path of travel caused receptacle <NUM> to travel over <NUM> LIMs <NUM>, only the <NUM> or <NUM> LIMs closest to the actual, current location of receptacle <NUM> need be energized at any point in time). This may result in significant energy savings, as well as a significant reduction in moving parts that may require maintenance, create audible noise and generate dirt or dust within system <NUM>.

<FIG> show schematic side views of some alternate ways to mount LIMs <NUM> to surface <NUM> in accordance with embodiments of the present disclosure. In <FIG>, for example, LIM <NUM> is mounted directly to the underside portion of receiving surface <NUM>. This implementation may provide LIMs <NUM> in close proximity to portable receptacles <NUM> as they pass by, but maintenance and repair may become difficult in view of the fact that LIMs <NUM> are essentially fixed in place. <FIG>, on the other hand, shows a pair of guide rails <NUM> that are mounted to the underside of receiving surface <NUM>. In this example, LIMs <NUM> can be inserted between rails <NUM>, which apply pressure to LIM <NUM> to keep it in place. This technique can simplify maintenance and repair, but installation may be time consuming as each LIM <NUM> would need to be installed individually. <FIG> shows an installation where a pair of small, U-shaped components or brackets are mounted to the underside of receiving surface <NUM> in order to retain LIMs <NUM> when they are installed therein. The installation shown in <FIG> provides similar advantages to the installation shown in <FIG>, however, it requires less material and provides access to more sides of LIMs <NUM>. <FIG> shows yet another potential installation of LIMs <NUM>. As shown in <FIG>, LIMs <NUM> may be incorporated at least partially or completely within receiving surface <NUM> itself, in which case receiving surface <NUM> may need to be implemented as something more than a single sheet of metal. Such an implementation could simplify construction and/or expansion of materials handling system <NUM>, because LIMs <NUM> would already be located in place once receiving surface <NUM> had been installed. Alternatively, in embodiments not part of the invention, LIMs <NUM> may be mounted to an upper side of receiving surface <NUM> using any of the additional rails, components or brackets described above with reference to <FIG>, and the LIMs <NUM> may be at least partially or completely embedded within receiving surface <NUM> (e.g., partially embedded within channels or pockets from the upper side of receiving surface <NUM>). In the case where LIMs <NUM> may at least partially protrude above the upper side of receiving surface <NUM>, the lower surface of receptacles <NUM> may be configured to provide any additional required clearance (e.g., as shown in <FIG>) to travel unimpeded over LIMs <NUM>. Installation, maintenance and repair of LIMs <NUM> may be facilitated by mounting LIMs <NUM> to the upper side of receiving surface <NUM>, depending on the accessibility and installed height of receiving surface <NUM> within system <NUM>.

<FIG> shows a schematic three dimensional perspective view of materials handling system <NUM>, which includes receiving surface <NUM>, guides <NUM>, and LIMs <NUM>. Portable receptacles <NUM> may move along receiving surface <NUM> in the "X" direction as a result of a force acting on portable receptacles <NUM>. For example, a magnetic field B generated by LIM <NUM> perpendicular to the X direction of travel (as shown in <FIG>), may generate a current I within conductive element <NUM> on a lower portion of portable receptacles <NUM>, which, based on Ampere's Law, creates a force F on the conductive element <NUM> that causes receptacle <NUM> to move in the X direction. That force operates to move receptacle <NUM>, for example, from LIM 106C to LIM 106B, which then creates its own force F that continues the movement of receptacle <NUM>. Once receptacle <NUM> has moved within the magnetic field B generated by LIM 106A, a current is again generated in conductive portion <NUM> of receptacle <NUM>, which creates a force F that continues the movement of receptacle <NUM> along direction X.

<FIG> shows a schematic three dimensional perspective view of materials handling system <NUM> in which embodiments are disclosed where a generated force F applied to a single receptacle causes multiple receptacles <NUM> to move along the X direction on receiving surface <NUM>. For purposes of illustration, LIMs <NUM> in <FIG> are labeled individually as LIMs 106A and 106C, and receptacles <NUM> are labeled individually as receptacles 110A, 110B, and 100C. As receptacle 110C moves in proximity to LIM 106C, LIM 106C may be activated by control module <NUM> described herein such that a magnetic field B is generated by LIM 106C in substantially the same direction as previously described (see <FIG>), which generates a current I in conductive portion <NUM> of receptacle 110C that causes a force F to be generated at receptacle 110C, moving receptacle 110C past LIM 106C. In this instance, the signals generated by control module <NUM> should create enough force such that all of receptacles 110A, 110B and 110C are driven in the X direction from a single applied force to receptacle 110C. Alternatively, receptacles 110A, 110B, and 110C may have enough kinetic energy when approaching LIM 106C such that they may continue to move along the X direction all the way to LIM 106A without LIM 106C applying any additional force on receptacle <NUM> (this depends, for example, on many factors such as the location and spacing of LIMs <NUM> from each other and/or the configuration or elevations of receiving surface <NUM>). Persons of ordinary skill in the art will recognize that LIM 106C, in one exemplary embodiment, may generate a magnetic field B in a direction different than the magnetic field generated by LIM 106A, which may modify the direction and/or speed of movement of the portable receptacle <NUM>.

Once receptacle <NUM> begins to move across LIM 106C, the counter electromotive force, or back EMF, generated by receptacle <NUM> can be utilized to identify the location of receptacle <NUM> to control module <NUM> (which, in turn, may provide that information to data store <NUM> or storage <NUM>). Back EMF, for example, occurs due to the electromagnetic field induced by conductive element <NUM> passing by LIM 106C. The back EMF is measurable at any point along receiving surface <NUM>, and in particular, at each of LIMs <NUM>. The back EMF may, in some embodiments, be used as a means to detect when each receptacle <NUM> reaches a specific LIM <NUM>. As another example, the back EMF may be used to determine the current approximate weight of each portable receptacle <NUM> based on the strength of the magnetic field generated by the corresponding LIM <NUM>, and the inherent impedance of the LIM <NUM>. However, in some embodiments, one or more additional sensors (for example, see <FIG>, and as described below with respect to <FIG>) may be included within materials handling system <NUM> that can be coupled to control module <NUM> via network <NUM> to detect when a specific receptacle reaches a specific position within system <NUM>, as well as, or in addition to, the weight or content type of one or more items within a given receptacle <NUM>.

Control module <NUM> may further cause LIM 106C to generate a magnetic field B that provides a force F that acts on receptacle <NUM> that may cause receptacle <NUM> to continue moving along the X direction toward a subsequent LIM <NUM>. This process may be repeated any number of times to move receptacle <NUM> along receiving surface <NUM>. Furthermore, as illustrated in <FIG>, each individual receptacle <NUM> can be individually manipulated through handling system <NUM>. Persons of skill in the art will appreciate that receptacles <NUM> may be moved along the X direction in different manners than described above. For example, receptacles <NUM> may be moved by LIM 106C directly to LIM 106A, such that LIM 106B is not activated at all. In that instance, for example, LIM 106B may be utilized as a back-up LIM providing redundancy in the event that LIM 106A or LIM 106C fails to operate in the intended manner. Alternatively, receiving surface <NUM> may include more than one axis of travel and LIM 106B might be utilized to change the direction of receptacle <NUM> from traveling along the X direction to another direction (see, for example, <FIG> below).

<FIG> shows a schematic top view of a materials handling system <NUM> that may include receiving surface <NUM> (which, as described above, may include one or more low-friction surfaces), LIMs <NUM> aligned along multiple directions or axes W, X, Y and Z, and direction switches <NUM> that may be utilized to change the direction of a receptacle <NUM>, initially traveling along one direction, to move along another different direction, such as when a receptacle is traveling in the X direction and is moved to one of direction W, direction Y or direction Z. For purposes of illustration, switches <NUM> are labeled as switch 138A, switch 138B and switch 138C, which are operable to cause the direction of travel of receptacles <NUM> to change. In some embodiments, switches <NUM> may be implemented as additional LIMs that change the direction of a portable receptacle through the use of applied magnetic forces. In other embodiments, switches <NUM> may be implemented as mechanical arms that can be controlled or actuated by signals from control module <NUM>. Moreover, not all of the LIMs <NUM> shown in <FIG> may be required for normal operations. For example, the LIMs along the X direction are labeled alternately as LIM 106A and LIM 106B such that receptacles <NUM> may be driven by LIMs 106A, while LIMs 106B are utilized as redundant backup LIMs in the event of failure of one or more of LIMs 106A. Each of LIMs <NUM>, 106A and 106B is coupled to control module <NUM>, such that control module <NUM> can provide operational commands to each of LIMs <NUM> in system <NUM>.

Materials handling system <NUM>, like materials handling system <NUM> described above, is in most instances just a portion of a much larger inventory management system that can be utilized to collect and transport individual items. Accordingly, persons skilled in the art will appreciate that a complete materials handling system might include one or more instances of systems <NUM> and <NUM> (or other configurations that are not shown). Materials handling system <NUM> can direct portable receptacles along the X direction, or from the X direction to the W direction, the Y direction or the Z direction, depending on the desired destination. For example, receptacle <NUM> (shown in <FIG>) can be moving along the X direction from a given LIM <NUM> to another LIM <NUM>. Control module <NUM>, in one embodiment, may send a generated signal to LIM 138A that causes LIM 138A to generate a magnetic field B that provides a force F that can act on conductive portion <NUM> of receptacle <NUM> to cause receptacle <NUM> to change direction from the X direction in which the receptacle is traveling to the W direction, where it may be picked up by one or more of LIMs106 that are located along the W direction. Similarly, LIM 138B may be utilized to generate a magnetic field B such that a force F acts on receptacle <NUM> causing receptacle <NUM> to change direction from the X direction to the Z direction; LIM 138C can similarly cause receptacle <NUM> to change direction from the X direction to the Y direction; and LIM 138D can cause receptacle <NUM> to change direction from the X direction to the Q direction.

While <FIG> shows a more complex implementation of a materials handling system <NUM>, it should be noted that such systems, utilizing the principles described herein, can be configured such that receptacles <NUM> may enter and exit the system from a variety of locations. For example, a path along the Q direction may be utilized such that receptacles <NUM> traveling along the Q direction travel directly across surface <NUM> through the area by which other receptacles are traveling in the X direction. System <NUM> may be capable of implementing this feature because the system is inherently deterministic, such that the location of virtually every receptacle <NUM> is known to control module <NUM>. Accordingly, control module <NUM> could stop a given receptacle <NUM> traveling along direction Q prior to the intersection with direction X while waiting for traffic of receptacles traveling in the X direction to clear. Once an opening is identified, control module <NUM> could send the appropriate signal to LIMs <NUM> along direction Q to cause the stopped receptacle <NUM> to again move and now travel across the portion of the system normally traveled by receptacles <NUM> moving in the X direction.

<FIG> also shows an illustrative work station <NUM>, which is intended as an example of the countless work stations that exist within materials handling systems <NUM> and <NUM>. Work stations <NUM> may include, for example, work stations where empty receptacles are loaded onto or removed from receiving surface <NUM>, work stations where items are loaded into or removed from receptacles <NUM> for storage in system <NUM>, work stations where items are removed from inventory and loaded into or removed from receptacles <NUM> for shipment to consumers, work stations where shipping materials are stored for preparation of shipments, work stations where items and/or receptacles <NUM> are subject to quality checks or maintenance, etc. Work stations <NUM> may be utilized, for example, as follows. A given portable receptacle <NUM> enters the portion of system <NUM> shown at location "S" traveling along direction X. Switch 138A (e.g., mechanical switch or LIM switch) is activated by control module <NUM> which causes given receptacle <NUM> to be redirected from traveling in direction X to travel in direction W. When the receptacle arrives in the vicinity of LIM <NUM>, control module <NUM> issues a stop signal to LIM <NUM> that causes the receptacle to stop in front of work station <NUM> (LIMs <NUM> may be implemented, for example, such that an applied magnetic field can be used to stop a receptacle <NUM> or move it forward or backward). At work station <NUM>, for example, one or more consumer-selected items may be loaded into receptacle <NUM>, or any other processing may be performed with respect to items or the receptacle <NUM>. This can be accomplished through a human interface, whereby an individual places the item(s) in receptacle <NUM> and indicates to control module <NUM>, e.g., via user device <NUM>, that the task is complete; or via a robotic interface, in which case control module <NUM> would receive a signal from the robotic interface when loading was complete. Once loading was complete, control module can provide an activation signal to LIM <NUM> that would cause the receptacle to again begin traveling along direction W to its next destination (which may, for example, be a different work station <NUM>). Eventually, for example, that same receptacle might return to traveling along direction X until the order preparation is complete and the order is sent off for shipping.

<FIG> shows a schematic side view of a materials handling system <NUM> which is similar to previously described systems <NUM> and <NUM>, except that system <NUM> includes portions of the receiving surface <NUM> having various elevations, e.g., a portion that goes up an incline U and a portion that goes down a decline D. System <NUM> includes a receiving surface <NUM> within which LIMs <NUM> are mounted (in the manner previously shown and described with respect to <FIG>). Receptacles <NUM> move along direction X, propelled by electromagnetic force from LIMs <NUM>. In this case, the spacing between LIMs <NUM> varies depending on where LIMs are located. For example, LIMs <NUM> that are located on the incline portion U of the system <NUM> are labeled as LIMs <NUM>, and may be spaced closer together to insure that control is maintained over receptacle <NUM> (but such close spacing is not required). Similarly, LIMs 106V are located on the decline portion D of the system <NUM> with closer spacing to again maintain control of receptacle <NUM> as it travels along direction X (similarly, such closer spacing may not be required).

As portable receptacles <NUM> move up incline U and down incline D, control module <NUM> may vary the signals applied to LIMs <NUM> and 106V to account for the variations in speed caused by the change in varying elevation and gravitational forces. Moreover, because feedback of traveling speeds can be provided to control module <NUM> in an essentially instantaneous manner through the use of back EMF, control module <NUM> can generate varying control signals such that the speed of receptacles <NUM> is maintained in a relatively constant manner (if that is the desired result).

<FIG> shows a schematic three dimensional perspective view of a representative portable receptacle <NUM>, including side walls or portions 110W, 110X, 110Y, and 110Z, a base portion 110V which has conductive element <NUM> attached to or integrated therein (for example, in <FIG>, conductive element <NUM> is shown to be covering base portion 110V). The conductive element may, in some examples, correspond to a strip or piece of copper, iron, silver, aluminum, or any other conductive material, or any combination thereof. Or the conductive element may be formed from material that is doped with conductive particles (e.g., copper, iron, silver, etc.) into the non-conductive materials used to form the base portion or side walls or portions of the receptacle. Further, the conductive element is placed on any surface of base portion 110V, or at least partially or completely embedded within base portion 110V, or in embodiments not being part of the invention, the conductive element may be placed in any surface of receptacle <NUM> (for example, the left and/or right side walls of receptacles <NUM> may include a conductive element in which case LIMs <NUM> could be mounted on stand-alone poles above and/or along the sides of surface <NUM> such that the conductive elements pass by proximate to the LIMs <NUM>). It can be beneficial for portable receptacle to be as light-weight as possible, as this will reduce the energy required to move receptacles throughout the materials handling system. In order for receptacles <NUM> to be able to interact with LIMs <NUM>, at least a portion of receptacle <NUM> needs to be conductive. Accordingly, the receptacle <NUM> shown in <FIG> includes non-conductive side walls or portions 110W, 110X, 110Y and 110Z, while base portion 110V (which is underneath conductive element <NUM> in <FIG>) of receptacle <NUM> includes conductive element or insert <NUM> that can interact with LIMs <NUM>. While receptacle <NUM> shown in <FIG> is rectangular in shape, one of ordinary skill in the art will appreciate that a receptacle may have other shapes, such as the round shapes shown in <FIG>, other polygonal shapes or any other shapes configured to receive items therein.

The actual implementation of inclusion of a conductive portion into receptacles <NUM> can vary greatly within the scope of the claims. For example, <FIG> show various illustrative schematic top views of alternate configurations of conductive element <NUM> within the base portion of portable receptacle <NUM>. Persons of ordinary skill in the art will recognize that these are merely exemplary illustrations and that there are a multitude of different configurations to which the teachings of the disclosure herein can be applied. For example, conductive elements <NUM> may themselves be of any suitable size and/or shape, provided that there is enough conductive material to interact with the magnetic field B generated by LIMs <NUM>. Furthermore, as mentioned above, the composition of conductive elements <NUM> may vary from a single conductive material, to a compound of multiple conductive materials, to mixtures of non-conductive and conductive materials. For example, the conductive materials may include an array or grid of coils that are aligned such that an applied magnetic field would cause receptacle <NUM> to move at a right angle down a different path than the path on which it would otherwise travel. In that case, the change in direction may be less than ninety degrees due to the forward momentum that would also need to be overcome when the field was applied.

In <FIG>, conductive element 130A is located in base portion 110V of receptacle <NUM> such that it can pass directly over any one of LIMs <NUM> which are aligned along the intended path of travel of receptacles <NUM>. In general, the size and orientation of conductive element <NUM> can be configured such that any of LIMs <NUM> can affect the trajectory and speed of receptacle <NUM>, as described above. Although conductive element or insert 130A is located at a first position along base portion 110V, in some examples, conductive element 130A may be positioned along any other position along base portion 110V, such as proximate side walls or portions 110W, <NUM>0X, 110Y, or 110Z, and/or in a center of base portion 110V.

<FIG> shows an alternate arrangement in which conductive strips of material 130B are embedded within base portion 110V. For example, conductive strips 130B may form a criss-cross pattern along the base portion of receptacle <NUM>, a checker board pattern, any other pattern, or any combination thereof (only a stripe pattern is shown). In some examples, conductive strips 130B may be on an outer surface of base portion 110V, however, at least a portion of conductive strips 130B may be embedded within a non-conductive material forming base portion 110V.

<FIG> shows another alternate configuration of conductive elements or inserts <NUM> applied to receptacle <NUM>, in which two conductive elements 130C and 130D are applied to or within base portion 110V. For example, conductive elements 130C and 130D may be attached to base portion 110V, but located close to either side wall or portion (e.g., 110W & 110Y or 110X & 110Y) of base portion 110V. In some examples, conductive elements 130C and 130D can be embedded within base portion 110V, which may be formed of a non-conductive material (e.g., similar to the non-conductive material used to form side walls or portions 110W-Z).

In other configurations, conductive elements 130C and 130D can be oriented such that additional control of receptacle <NUM> may be accomplished by utilizing LIMs <NUM> configured to be aligned with elements 130C and 130D. For example, receiving surface <NUM> may include a first LIM oriented in a first direction and a second LIM oriented in a second direction. When portable receptacle passes across the first LIM, conductive element 130C may interact with the first LIM such that portable receptacle <NUM> moves in a first direction. When portable receptacle passes across the second LIM, however, conductive element 130D may interact with the second LIM, thereby causing portable receptacle <NUM> to move in a second direction. In this particular scenario, a single portable receptacle <NUM> is capable of moving in any number of directions based on the orientation of the LIMs located on receiving surface <NUM> of materials handling system <NUM>.

<FIG> shows yet another configuration of base portion 110V. In this case, a conductive element 130E is applied to, or embedded in, base portion 110V, as well as an additional item, such as an identifier, tag or other sensed element <NUM>. Sensed element <NUM> may, in some examples, be used to monitor the location of receptacle <NUM> as it travels about materials handling system <NUM>, <NUM> and/or <NUM>. Sensed element <NUM> may be any type of identifier or tag including, but not limited to, a Radio Frequency Identification ("RFID") tag, a bar code, a QR code, an alphanumeric identifier, or other identifier. Sensor <NUM> of <FIG>, for example, may, in one examples, read, scan, image or otherwise identify sensed element <NUM> in order to detect portable receptacle <NUM> and/or one or more items stored therein. In response to detecting sensed element <NUM>, sensor <NUM> may send a signal to sensor module <NUM> of control module <NUM> to cross check whether or not portable receptacle <NUM> is moving in a correct direction (e.g., to a correct end point) and/or if portable receptacle includes the correct items therein, for example, by reference to information stored in data store <NUM> or storage <NUM>.

<FIG>, on the other hand, shows a configuration in which three different conductive elements 130F, <NUM>, and <NUM> are included within base portion 110V in order to provide more precise control of receptacle <NUM>. For example, conductive portion 130F may be utilized to move receptacle <NUM> along a first direction, conductive portion <NUM> may be utilized to move receptacle <NUM> along a second direction, and conductive portion <NUM> may be utilized in changing direction of receptacle <NUM>.

<FIG> shows a schematic cross-sectional view of receptacle <NUM>. According to the invention, <FIG> shows that conductive material 130N has been impregnated into base portion 110V, e.g., by doping the material of the base portion with conductive material during manufacturing of receptacle <NUM> (in <FIG>, base portion 110V and conductive element 130N are, in essence, one in the same and only reference numeral 130N is shown). In that instance, the use of conductive material might not be apparent to an observer or an employee handling the receptacle <NUM>. Base portion 110V, in this particular scenario, may be formed of a non-conductive material, such as plastic or cardboard, that has conductive elements impregnated therein such that base portion 110V retains the quality and appearance of a non-conductive material, similar to side walls or portions 110W-Z, but includes the appropriate conductive features for interacting with various LIMs <NUM>.

<FIG> show alternate physical configurations of receptacle <NUM> which are intended to provide a reduced surface area that would be in contact with surface <NUM>, to reduce the surface friction between those surfaces. <FIG>, for example, shows a schematic top view of receptacle <NUM> including conductive element <NUM>. <FIG> shows a schematic side view of the receptacle shown in <FIG>, in which only a small portion of the outer edge of receptacle <NUM> extends fully to a lower surface that contacts surface <NUM>. More particularly, only the outer rim 110R of the base portion extends fully to the bottom of receptacle <NUM>, while conductive element <NUM> is raised slightly so that it is not in contact with surface <NUM> while receptacle <NUM> is being transported within materials handling system <NUM>, <NUM>, and/or <NUM>. Similarly, <FIG> show another configuration for base portion 110V in which only legs <NUM> of base portion 110V extend down onto surface <NUM> while receptacle <NUM> is being transported within system <NUM>, <NUM>, and/or <NUM>, further reducing the surface friction between surface <NUM> and receptacle <NUM>. In this configuration, only a very small portion of receptacle <NUM> is ever in physical contact with receiving surface <NUM>; accordingly, the surface friction that needs to be overcome for inducing movement of an empty receptacle may be significantly reduced as compared to a receptacle with a continuous planar bottom surface. Moreover, the conductive element 130J is shown as a general representation in <FIG> and can, for example, be configured in at least any manner previously described with respect to <FIG>. It also may be beneficial to utilize wheels or rollers in place of legs <NUM> to further reduce the surface friction between surface <NUM> and receptacle <NUM>. In such an implementation, surface <NUM> and receptacle <NUM> may be designed such that the wheels or rollers <NUM> could fit within a portion of surface <NUM> to help guide receptacle <NUM> to the proper location.

<FIG> show three dimensional schematic views of receptacle <NUM>, which is substantially similar to receptacle <NUM>, except that it is shaped in a cylindrical manner instead of a rectangular shape. Moreover, persons of ordinary skill in the art will appreciate that a variety of other shapes, such as other polygons or any other shapes configured to receive items therein, may also be utilized as portable receptacles in accordance with the present disclosure. In particular, <FIG> shows a configuration of receptacle <NUM> in which conductive element <NUM> is located within base portion 110V of receptacle <NUM> such that it may be in contact with receiving surface <NUM> while receptacle <NUM> moves along material handling system <NUM>, <NUM>, and/or <NUM> (in <FIG>, base portion 110V and conductive element <NUM> are shown in the same manner as base portion 110V and conductive element 130J described above). <FIG>, on the other hand, shows an alternate version of receptacle <NUM> in which conductive element <NUM> is raised above the bottom of base portion 110R, similar to that shown in <FIG>, to reduce surface friction.

<FIG> shows a flow diagram of a method <NUM> for fulfilling an order utilizing a portable receptacle that is at least partially conductive within a materials handling system in accordance with the disclosure herein. In this regard, it may be helpful to also review <FIG> and the accompanying description above, particularly with regard to control module <NUM> and the modules contained there. The method starts at step <NUM>. In step <NUM>, an instruction is given, for example by control module <NUM>, to direct that a receptacle be placed at a given location within the materials handling system (that instruction may be carried out by an employee or by an automated part of the system that could place a receptacle <NUM> on to an entry point on receiving surface <NUM>). In step <NUM>, an analysis is performed to determine the path the placed receptacle needs to travel to complete the order for that receptacle, including determining which LIMs will be required to propel the receptacle around the materials handling system. This analysis may be performed, for example, by control module <NUM>.

In step <NUM>, a query is made to determine whether the order is complete for the corresponding receptacle (this query could be made, for example, by processor(s) <NUM> within control module <NUM> of a user device <NUM> which is being operated by an employee; alternatively, the status of a given order being processed may be stored in memory <NUM> and accessed by processor(s) <NUM> in order to complete the inquiry). If the order is not complete, in a step <NUM>, the appropriate LIM is sent a signal (by signal generating module <NUM>, which may be in response to an activation signal from processor(s) <NUM>), which activates the LIM to generate a magnetic field B, which induces a current I in the conductive portion of the receptacle and creates a force F that moves the receptacle to the "next location. " Next, in a step <NUM> another query is made to determine whether the "next location" at which the receptacle arrived is a workstation, other processing area or a final destination (this query could be made by processor(s) <NUM>, for example, by seeking the status of one or more sensors <NUM> via sensor module <NUM>). If the "next location" is not a work station, other processing area or the final destination, it is assumed that the receptacle is at an intermediate LIM and that the receptacle needs to be again transported to the "next location," so control returns to step <NUM>.

Once a work station, other processing area or the final destination is reached and the query at step <NUM> is true, the task at the work station, other processing area or the final destination is performed in step <NUM>. This task or function may include placing one or more items in the receptacle (which may occur manually, through a robot or a combination thereof). This task also may include placing packaging materials in the receptacle, and/or it may include removing the contents of the receptacle, placing the contents in a shipping container and then placing the packaged items back in the receptacle for transportation to the shipping work station (there can be a variety of tasks performed at work stations, other processing area or the final destination, only some of which have been described herein - persons skilled in the art will appreciate that the individual workstation and processing tasks described are not intended to limit the disclosure or claims in any way). Once the work station or processing task has been performed, control is returned to the query at step <NUM> where processor(s) <NUM> can determine whether the order is complete. If it is not yet complete, control is returned to step <NUM> to start the process of moving the receptacle to the next work station (in which case processor(s) <NUM> would continue to send signals to signal generation module <NUM> to cause module <NUM> to generate and send drive signals to specific LIMs <NUM>), other processing area or the final destination as previously described. If the order is complete and the receptacle has arrived at the final destination, control stops in step <NUM>.

<FIG> shows a flow diagram of a method <NUM> for controlling the movement of a portable receptacle that is at least partially conductive within a materials handling system in accordance with the disclosure herein. Method <NUM>, which starts at step <NUM>, may be carried out, for example, by control module <NUM>, which was described in detail above with respect to <FIG> (as such, it may be helpful to refer back to the description of <FIG>, and in particular, to the description set forth in connection with control module <NUM> and the modules contained there). In step <NUM>, status information is received regarding an individual receptacle from one or more sensors (this may include, for example, utilizing sensor module <NUM> to gather information from one or more of sensors <NUM>, and for sensor module <NUM> to send that gathered information to processor(s) <NUM>). This information can relate to any of a number of different things, such as the identification of the individual receptacle, the location of the receptacle, the status of completion of the order intended for that receptacle, the current contents of the receptacle, the overall weight of the receptacle with the contents therein, etc. This information can be provided by one or more sensors which may include RFID readers, sensors to measure back EMF signals from one or more of the LIMs, imaging sensors, scanners, or other sensor devices.

Once the information has been obtained, in a step <NUM>, the individual receptacle and corresponding information are matched together and the physical receptacle and corresponding nearby LIM are identified and located within the materials handling system (this step can be carried out, for example, by processor(s) <NUM>, which may store such information about each active receptacle in memory <NUM> and/or storage <NUM>, and which could then update the stored information based on the received status information). Then, in a step <NUM>, the "next location" to which the individual receptacle is to travel is identified (this step could also be carried out by processor(s) <NUM>). This "next location" may be a work station, other processing area or the final destination or it may simply be the next LIM in sequence on the way to a work station, other processing area or the final destination in future steps.

In step <NUM>, control module <NUM> determines the direction in which a force should be applied by the LIM to the receptacle to propel it toward its "next location," and in step <NUM> control module <NUM> determines the amount of force that should be applied by the LIM to the receptacle (this determination may take into account, for example, the weight of the receptacle, the weight of the contents and/or a desired distance to be traveled). It should also be noted that the particular order of steps <NUM> and <NUM> is not critical, and that they may be reversed or combined into a single step, as appropriate. Once the direction and size of the applied force has been determined by control module <NUM> and that information is sent to signal generation module <NUM>, signal generation module <NUM>, in step <NUM>, generates an appropriate drive signal to be applied to the corresponding LIM. In step <NUM>, the generated signal is transmitted to the appropriate LIM by signal generation module <NUM> which causes that LIM to generate a magnetic field B that interacts with the conductive portion of the corresponding receptacle to induce a current I, that in turn creates a force F that moves the receptacle to the "next location. " The method stops in step <NUM> (or simply repeats until the outstanding tasks for the receptacle are complete).

Claim 1:
A materials handling system comprising a system for transporting a receptacle, and a plurality of receptacles, wherein the system for transporting a receptacle comprises:
a track comprising a receiving surface (<NUM>) configured to move a receptacle (<NUM>) of the plurality of receptacles along the track from a first position to a second position, wherein the receiving surface is a surface upon which the plurality of receptacles are arranged to move,
wherein each receptacle of the plurality of receptacles that is moveable by the system comprises a base and at least one side wall, wherein each receptacle of the plurality of receptacles that is moveable by the system further comprises a conductive element (<NUM>) arranged proximate to the receiving surface of the track, wherein the conductive element comprises at least a conductive material impregnated into the base of each receptacle of the plurality of receptacles;
a plurality of linear induction motors, LIMs, (<NUM>) disposed along the track, wherein the plurality of LIMs are located below the receiving surface by a given distance whereby the LIMs are operable to produce a force on the conductive element of a receptacle of the plurality of receptacles passing thereby; and
a control module (<NUM>) configured to control the force produced by at least one LIM of the plurality of LIMs on the conductive element of the receptacle passing thereby, wherein the control module is operable to control the force produced by the at least one LIM independently of other LIMs to propel the receptacle along the track independently of other receptacles.