Material handling device having transport vehicle

Abstract

To provide an apparatus for sorting a plurality of items.SOLUTION: An apparatus for sorting a plurality of items comprises: a plurality of sort destinations which are located so as to be apart from each other in a vertical direction; a plurality of delivery vehicles which deliver the items to the sort destinations and are movable in the vertical direction; a controller which provides a signal for controlling operation of the delivery vehicle that delivers the items to the sort destination; a first detector which detects a first feature of each item; and a second detector which detects a second feature of each item. The controller is configured to decide the sort destination of the first item on the basis of the detected first feature for the first item, and is configured to set a position in the vertical direction of the first delivery vehicle with respect to the decided sort destination to various positions according to the second feature of the first item by controlling the operation of the first delivery vehicle.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] <Priority Claim> This application claims priority to U.S. Provisional Patent Application No. 62 / 277,253, filed January 11, 2016, U.S. Provisional Patent Application No. 62 / 331,020, filed May 3, 2016, and U.S. Provisional Patent Application No. 62 / 374,218, filed August 12, 2016. Each of the above applications is incorporated herein by reference.

[0002] The present invention relates to a material handling system, and more particularly to a material handling system capable of receiving and sorting items using a plurality of automated transport vehicles. [Background technology]

[0003] Sorting and collecting items to fulfill customer orders can be tedious and time consuming. Similarly, many large organizations have vast storage areas in which countless items are stored. Manually sorting and retrieving items from hundreds or thousands of storage areas is labor intensive. In many areas, automated picking is being developed to reduce labor costs and improve customer service by reducing the time required to fulfill customer orders. However, known material handling systems that automatically handle materials are either prohibitively expensive or contain limitations that reduce their effectiveness. Thus, there is a need to automatically sort and / or collect items in a variety of material handling applications.

[0004] Additionally, in conveyor and sortation systems, objects are typically transported onto or off of the conveyor. Objects are transported from one conveyor to another (eg, from a delivery conveyor to a receiving conveyor). In many automated material handling systems, such transfer occurs only after the object reaches a particular location along the transport path (eg, an object storage location and / or an object retrieval location). The performance of an object handling system is determined, among other things, by the speed at which each object is moved to and / or from its application location.

[0005] In some material handling systems, the conveyor may form part of a movable transport vehicle that is used to transport objects to or retrieve objects from a location where a transfer operation is to be performed. In material handling systems of this type, failure to quickly and accurately determine when an object has been transferred to or from a conveyor can delay (or prevent) the movement of the transport vehicle to its next location. Summary of the Invention

[0006] This Summary is provided to introduce a selection of concepts in a simplified form. The concepts are further explained in the detailed description below. This Summary is not intended to identify key features or essential features of the claimed subject matter, but is intended to be used as an aid in determining the scope of the claimed subject matter.

[0007] The present invention provides a number of aspects that form part of a material handling system. The material handling system may include one or more of the many aspects of the present invention, which are further described below.

[0008] According to one aspect, the present invention provides a material handling device for sorting a plurality of items. The material handling apparatus includes a plurality of sorting destinations, a plurality of transport vehicles for transporting items to the sorting destinations, and a controller for controlling the loading of the items onto the transport vehicles or the unloading of the items from the transport vehicles. A controller is provided that provides signals that control operation of the haul vehicle. A database for storing a plurality of vehicle movement profiles is also provided. The controller retrieves a vehicle movement profile according to the characteristics determined for each item, and the controller controls movement of a haul vehicle according to the retrieved vehicle movement profile. The vehicle movement profile may include one or more of acceleration, deceleration, and cornering speed.

[0009] According to another aspect, the invention may include a track system for guiding a transport vehicle to the sorting destination.

[0010] According to another aspect, the invention includes a scanner for detecting characteristics of each item by scanning the items, the detected characteristics may be determined for each item that the controller uses to retrieve a vehicle movement profile. The detected feature may be a product identification code of the item.

[0011] According to yet another aspect, the detected characteristic may be one of the length, width, height, weight, or shape of the item.

[0012] In accordance with another aspect, the present invention provides a material handling device for sorting a plurality of items to a plurality of destinations, and a plurality of transport vehicles for transporting the items to the destinations. The material handling device may include a controller that provides signals to control operation of one of the transport vehicles that transports one of the items to one of the destinations. The central controller may control operation of the haul vehicle in response to the determined characteristics of each item, such that the haul vehicle assumes different positions relative to a destination in response to the determined characteristics.

[0013] According to a further aspect, the invention provides a sortation destination in the form of an output bin, said output bin having a rear end through which items pass as they are discharged into the output bin.

[0014] According to another aspect of the invention, an output bin of a material handling system may include an open rear end.

[0015] According to another aspect of the invention, an output bin of a material handling system may include a removable or collapsible rear wall.

[0016] In accordance with another aspect of the present invention, a material handling method for sorting a plurality of items is provided. The material handling method may include loading items onto a transport vehicle to be transported to an output bin, and moving the transport vehicle to the output bin. The material handling method may further include discharging items from the transport vehicle into an output bin and monitoring the location of the items on the transport vehicle. The material handling method may also include controlling operation of a transport vehicle based on the step of monitoring the location of the item, and the step of controlling operation of the transport vehicle may include controlling the transport vehicle to attempt to move the item to a desired location on the transport vehicle.

[0017] According to a further aspect, the present invention provides a method of material handling comprising moving a transport vehicle along a guide member. The guide member may include a surface and the transport vehicle may include a rotatable element, and moving the transport vehicle along the guide member may include moving the rotatable element along the surface of the guide member. Moving the transport vehicle may include moving the transport vehicle vertically.

[0018] According to another aspect, the invention includes a material handling method for sorting items using a plurality of transport vehicles, including controlling acceleration or deceleration of the transport vehicles and controlling the position of the items on the transport vehicles.

[0019] According to a further aspect of the invention, a material handling method for sorting items using a transport vehicle includes driving a conveyor belt of the transport vehicle to move items on the transport vehicle while the transport vehicle moves along a track.

[0020] According to another aspect, the present invention provides a material handling method for sorting items using multiple transport vehicles, comprising the step of continuously monitoring the position of items on the transport vehicles as the transport vehicles move to an output bin.

[0021] In another aspect, the present invention provides a material handling apparatus for sorting a plurality of items, the material handling apparatus including a plurality of transport vehicles guided by a track to transport the items to one or more destinations. The material handling equipment may include a loading station for loading items onto a transport vehicle. The item may be analysed to detect a first characteristic before the item is loaded onto the delivery vehicle. A recirculation system may be provided to recirculate items from a location along the track to the input station.

[0022] In another aspect, the present invention provides a material handling apparatus for sorting a plurality of items, the material handling apparatus including a plurality of transport vehicles guided by a track to transport the items to one or more destinations, the material handling apparatus having a qualification station for detecting first and second characteristics of items carried by the transport vehicles before the items are loaded onto the transport vehicles at a loading station. The sortation system may include a recirculation path that provides a path along which items can be transported along the track. The recirculation path may have a first end and a second end, the first end being vertically higher than the second end. The second end may be located adjacent to an input station such that items disposed on the first end of the recirculation path tend to move downwardly toward the second end adjacent to the input station.

[0023] According to another aspect, the present invention provides a material handling apparatus for sorting a plurality of items, the material handling apparatus may include a waste area located vertically lower than a first end of a recirculation path. The recirculation path may be a roller bed. The recirculation path may be a chute or a ramp. The recirculation path may include a conveyor including one or more movable belts or belt links.

[0024] According to yet another aspect, the present invention provides a material handling apparatus having a controller for controlling operation of a transport vehicle, wherein in response to a signal received from a scanning station relating to a first characteristic of an item, the transport vehicle is directed to an entrance of a recirculating path at which the controller controls the transport vehicle to discharge the item onto the recirculating path. The recirculation path may carry items back to the input location. At the entry station, the items may be reprocessed at a qualification station. Additionally, the item is directed to a disposal area in response to a signal from the scanning station relating to a second characteristic.

[0025] According to another aspect of the present invention, a material handling apparatus is provided in which a controller controls a transport vehicle in response to a signal from a qualification station to direct the transport vehicle to one of the destination areas.

[0026] According to another aspect, the present invention provides a material handling method for sorting a plurality of items, comprising the steps of scanning the items and selectively elevating the items above a height of an input area based on the scanned characteristics. The material handling method may also include, after the step of selectively lifting the items, the step of selectively conveying the items down a recirculation path to an input area. The material handling method may include the step of selectively sorting the items after the step of selectively lifting.

[0027] According to another aspect, a material handling method may include moving an item to an input area. The material handling method may include scanning an item to detect a first characteristic of the item. Optionally, the material handling system may include scanning the item for a second characteristic of the item. The material handling system may include selectively directing an item to a waste area based on scanning the item to detect a first characteristic or scanning the item to detect a second characteristic.

[0028] According to other aspects, selectively lifting the item may be based on scanning the item to detect a first characteristic or scanning the item to detect a second characteristic. Optionally, the step of selectively conveying the items down the recirculation path may be based on scanning the items to detect a first characteristic or scanning said items to detect a second characteristic. Additionally, selectively sorting the items into one or more destinations may be based on scanning the items to detect a first characteristic and scanning the items to detect a second characteristic.

[0029] A material handling system and method are described to facilitate reliable and accurate sensing of an object boundary, such as, for example, a leading and / or trailing surface of an object relative to an underlying conveyor surface. In accordance with one or more embodiments, a sensing and positioning mechanism for sensing an object boundary position relative to an underlying object support surface includes a linear array of multiple detectors, a laser light source, and a lens system sized and arranged to receive optical energy from the laser light source and collimate the received optical energy into a row along the multiple detectors. Each detector of the plurality of detectors receives the array of optical energy unless an object disposed on the underlying object support surface absorbs, reflects or refracts an amount of optical energy that exceeds a sensitivity threshold.

[0030] In another embodiment, a material handling system for transporting objects along a transport path includes an object transport mechanism defining an object support surface and operative to move an object supported by the object support surface in at least one object transport direction, and a sensing and positioning mechanism for sensing an occlusion between an object and a detection surface, the sensing and positioning mechanism including a linear array of multiple detectors, a laser light source, and a lens system sized and arranged to receive optical energy from the laser light source and collimate the received optical energy into a row along the multiple detectors, each detector of the multiple detectors receiving the row of optical energy unless an object positioned on the object support surface absorbs, reflects, or refracts optical energy in an amount that exceeds a sensitivity threshold.

[0031] In yet another embodiment, a transport vehicle for transporting objects along a transport path in a material handling system includes a first axis and a second axis extending transversely and perpendicularly to an object transport direction, a conveyor belt supported by the set of axes and defining an object support surface, an electric motor for driving at least one of the set of axes to move the conveyor belt and any objects disposed on the object support surface after the transport vehicle moves along the transport path to an object transfer location, and a sensing and positioning mechanism for sensing an object boundary position relative to the object support surface, the sensing and positioning mechanism including a linear array of multiple detectors, a laser light source, and a lens system sized and positioned to receive optical energy from the laser light source and collimate the received optical energy into a row along the multiple detectors. Each detector of the plurality of detectors receives the array of optical energy unless an object disposed on the object support surface absorbs, reflects or refracts an amount of optical energy that exceeds a sensitivity threshold.

[0032] In some embodiments, a transport vehicle for transporting objects along a transport path in a material handling system includes a set of shafts including a first shaft and a second shaft extending in a direction transverse to an object transfer direction, a conveyor belt supported by the set of shafts and defining an object support surface, an electric motor for driving at least one of the set of shafts to move the conveyor belt and any objects disposed on the object support surface after the transport vehicle moves along the transport path to an object transfer location, a first sensing and positioning mechanism positioned adjacent to the first shaft for sensing a first object boundary relative to the object support surface, and a second sensing and positioning mechanism positioned adjacent to the second shaft for sensing a second object boundary position relative to the object support surface. Each of the first and second sensing arrangements includes a linear array of multiple detectors, a laser light source, and a lens system sized and arranged to receive optical energy from a respective laser light source and collimate the received optical energy into a row along a corresponding number of detectors. [Brief description of the drawings]

[0033] The above summary and embodiments of the present invention are understood with reference to the accompanying drawings.

[0034] [Figure 1] FIG. 1 is a perspective view of a material handling device.

[0035] [Diagram 2] FIG. 2 is a plan view of the material handling system shown in FIG. 1.

[0036] [Diagram 3] FIG. 3 is a side view of one side of the track of the material handling system shown in FIG. 2.

[0037] [Figure 4] FIG. 2 is a perspective view of an alternative induction station for the material handling system shown in FIG. 1 having a recirculation system.

[0038] [Diagram 5] FIG. 5 is a side view of a material handling device incorporating the induction station and recirculation system shown in FIG.

[0039] [Figure 6] FIG. 5 is a plan view of a material handling system incorporating the induction station and recirculation system of FIG.

[0040] [Figure 7] 2 is a top perspective view of a transport vehicle of the material handling apparatus shown in FIG. 1.

[0041] [Figure 8] FIG. 13 is a front side view showing an object sensing and positioning mechanism.

[0042] [Figure 9A] 9 shows a linear array of detectors and a collimated optical energy source mounted on a common support structure and forming part of the object sensing arrangement of FIG.

[0043] [Figure 9B] 9B shows a reflector that can be positioned along the common support structure of FIG. 9A.

[0044] [Figure 10A] FIG. 1 is a front view of an object sensing arrangement that detects optically opaque objects as they cross a detection plane defined by the propagation of collimated optical energy in a direction transverse to the object's transport path.

[0045] [Figure 10B] A front view of an object sensing arrangement for detecting an object having at least one light refracting or reflecting portion while such an object passes through a detection plane defined by the propagation of collimated optical energy in a direction transverse to the object's transport path.

[0046] [Figure 11] FIG. 2 is a perspective view of an alternative transport vehicle in a material handling system.

[0047] [Figure 12] FIG. 12 is an electrical schematic diagram showing a circuit including a phototransistor and state sensing logic capable of transmitting a signal indicative of a change in sensing state when an object passes across the detection surface of one of the object sensing arrangements of FIGS. 8-11. [Figure 13] 2 is a front view of an alternative sorting station operable with the apparatus shown in FIG. 1; [Figure 14] FIG. 14 is a side view of the sorting station shown in FIG. 13. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] Some portions of the detailed descriptions which follow are presented in terms of operations based on complex digital signals stored within the memory of a particular apparatus or special purpose computing device or platform. In the context of this particular specification, the term specific apparatus or the like includes a general purpose computer that is programmed to perform particular functions pursuant to instructions from program software. In this context, operations and processes involve physical manipulations of physical quantities. Typically, though not necessarily, such quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to such signals as bits, data, values, elements, symbols, characters, terms, numbers, symbols, or the like. It should be understood, however, that all of these or similar terms are to be associated with appropriate physical quantities and are merely convenient labels. Unless otherwise stated, and as will become apparent from the discussion that follows, it will be appreciated that discussions throughout this specification using terms such as "processing," "computing," "calculating," "determining," and the like refer to the operation or processing of a particular apparatus, such as a special purpose computer or similar special purpose electronic computing device. Thus, in the context of this specification, a special purpose computer, or similarly special purpose electronic computing device, is capable of manipulating or transforming signals. The signals typically represent physical electronic or magnetic quantities within the memory, registers or other information storage, transmission or display devices of a special purpose computer or similar special purpose electronic computing device.

[0049] Please refer to the embodiments of the present invention in detail. Examples of these are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like items.

[0050] 1-3, a material handling apparatus for sorting items is indicated generally at 10. The material handling apparatus 10 includes a number of transport vehicles 200 that move along a track 110 and deliver items to a number of destinations or sortation locations, such as an output bin 190 . Items are loaded onto the transport vehicles 200 at a loading station 310 such that each transport vehicle 200 receives items to be transported to a sorting location. An input station, such as induction station 50, continuously delivers items to loading station 310. As the haul vehicle 200 moves along the track 110 towards the output bin 190, one or more characteristics of each item may be used to control the processing of the item. One or more characteristics of each item may be known from each item, or the one or more characteristics may be obtained by the system as it processes the items. For example, induction station 50 may include one or more scanning elements that detect one or more characteristics of an item.

[0051] From the loading dock 310, the haul vehicle 200 travels along the track 110 to its destination. The track 110 may include a horizontal upper rail 135 and a horizontal lower rail 140 that serves as a return section. A number of parallel vertical track sections 130 may extend between a horizontal upper rail 135 and a lower return section 140 . The output bins 190 may be disposed in columns between the vertical track sections 130 .

[0052] Haulage vehicle 200 is a semi-autonomous vehicle that may have an on-board power source and an on-board motor to power haulage vehicle 200 along track 110 . The transport vehicle may include a loading / unloading mechanism 210 , such as a conveyor, for loading parts onto and unloading parts from the transport vehicle 200 .

[0053] Because the material handling system 10 includes many haul vehicles 200, the positions of the haul vehicles 200 are controlled to ensure that the separate haul vehicles 200 do not collide with each other. In one embodiment, the material handling system 10 uses a central controller to determine the position of each haul vehicle 200 and to provide control signals to each haul vehicle 200 to control the advancement of the haul vehicles 200 along the track 110 . The central controller may also control the operation of various elements along the track, such as gates.

[0054] The following description provides details of the various elements of the material handling system, including the guide stations 50, the tracks 110 and the haul vehicles 200. A method of operation of the material handling system will also be described. In particular, the manner in which an item is conveyed may be controlled based on characteristics of the item. <Induction station>

[0055] At the guidance station 50, the items are guided into the material handling system by continuously loading the items onto the transport vehicles 200. The material handling system needs to be aware of the characteristics of the items since the characteristics of the items can be used to control the movement of the haul vehicle 200. In one example, known characteristics of the item may be stored in a central database and the material handling system tracks the progress of the item so that as the item reaches induction station 50 its identification has been made. Thus, since an identification of the item has been made, the material handling system 10 is able to retrieve data stored in a database regarding the characteristics of the item. Alternatively, the items are scanned at induction station 50 to identify one or more characteristics of each item.

[0056] In one embodiment, each item is manually scanned at induction station 50 to detect one or more characteristics of the item. These characteristics are used to ensure the identity of the item. Once an item has been identified, various characteristics of the item may be retrieved from a central database and the item may be subsequently processed based on the item's known characteristics. For example, induction station 50 may include a scanning station 80 that scans product codes, such as bar codes. Once the product code is determined, the system retrieves information about the product from a central database. This information is then used to control further processing of the item, as discussed further below.

[0057] In a second embodiment, the item is scanned at induction station 50 and various physical characteristics of the item are detected. For example, induction station 50 may measure characteristics such as the length, height, and / or width of an item. Similarly, the weight or shape of an item may be detected. These characteristics may be detected manually or automatically at induction station 50. For example, a series of sensors may be used to detect the length of an item, and a scale may be used to automatically measure the weight of an item. Alternatively, an operator may analyze each item and enter information about each item via an input device such as a mouse, keyboard, or touch screen. For example, the material handling system may include a touch screen that includes one or more questions or options. Packaging would be one example. Are the items in plastic bags, Bilster bags or unpackaged? Is the item flat, cylindrical or curved? The material handling system may include standard features; the operator need only be aware of the features of the elements if the features are more diverse than the standard ones. For example, a standard feature of an item may be a flat or rectangular shape. If the item is curved (eg, spherical or cylindrical), the operator enters information indicating that the item is curved. The item is then processed accordingly. Based on the detected information, the item is processed.

[0058] As mentioned above, a variety of configurations may be used for the induction station, including manual or automatic configurations, or a combination of manual and automatic features. In a manual material handling system, an operator inputs information for each item and the input system transports the items accordingly. In an automated entry system, induction station 50 includes elements that scan each item to detect information about each item. The induction station 50 then delivers the item according to the scanned information.

[0059] In an exemplary manual configuration, induction station 50 includes a work station having a conveyor, an input device such as a keyboard, and a monitor. An operator reads the information on the item, such as an ID tag, and uses a keyboard or other input device to enter the information from the tag into the material handling system, which then places it on the conveyor. The conveyor then transports the parts to a loading dock 310. For example, an operator may visually read information marked on an item. Alternatively, the operator may use an electronic scanner, such as a bar code reader, to read a bar code or other marking on the item. As the conveyor transports the items towards the loading dock 310, sensors positioned along the conveyor may follow the parts.

[0060] Alternatively, as shown in Figures 1-4, induction station 50 may include a scanning station 80 for automatically detecting characteristics of items. In particular, induction station 50 may include an input conveyor 55 . The input conveyor 55 receives the items and transports them to the scanning station 80 . The scanning station 80 is capable of detecting one or more physical characteristics of an item. From the scanning station 80 , the transfer conveyor 70 carries the items to a loading station 310 . At the loading station 310 the items are either loaded onto one of the transport vehicles 200 or passed to a disposal bin 325 .

[0061] The input conveyor 55 may be any of a variety of conveying devices designed to transport items. In particular, the input conveyor 55 may be designed to receive items that are placed on the conveyor. For example, the input conveyor 55 may be a horizontal conveyor belt or a horizontal roller bed, the latter being formed from a plurality of driven rollers that are generally horizontal, thus advancing items along the conveyor from the rollers.

[0062] The input conveyor 55 may be designed to allow an operator to select items from a supply of items located adjacent the input conveyor 55 . For example, a separate feed conveyor may carry a steady stream of items to induction station 50 . An operator may successively select items from the supply conveyor and place the items onto the input conveyor 5 . Alternatively, a larger container for the items, such as an output bin or other container, may be placed adjacent to the input conveyor 55 . An operator may select items one at a time from the supply bin and place each item onto the input conveyor 55 . Additionally, the input conveyor 55 may cooperate with a feed assembly that continuously transports items onto the input conveyor 55 . For example, a supply conveyor may convey a continuous stream of items to the input conveyor 55 . The input conveyor 55 may include a sensor for sensing when an item is conveyed off the input conveyor 55 . In response, the material handling system may control the operation of both the supply conveyor and the input conveyor 55 to feed the item forward from the supply conveyor onto the input conveyor 55 . In this manner, items may be manually conveyed onto the input conveyor 55 by an operator, or may be automatically fed by a separate conveying mechanism capable of conveying items to the input conveyor 55 .

[0063] The induction station 50 may include a scanning station 80 for detecting one or more characteristics of each item before it is loaded onto the transport vehicle 200 for transport or sorting.

[0064] Various factors may be detected to determine how to handle the item. For example, items typically need to be identified so that a material handling system can determine the location or container to which the item is to be delivered. This is usually done by determining a unique product code for each item. Thus, if the material handling system is capable of identifying items using product markings or other designation, the material handling system may electronically tag items to qualify them for sorting. For example, an operator may read a product identification code on an item and enter the product code into a material handling system using an input device such as a keyboard. If the product code entered by the operator matches the appropriate product code, the item may qualify for sorting. Alternatively, if the operator enters the product code incorrectly, or if the product code does not match a recognized item, the material handling system may electronically tag the item as not qualified.

[0065] Similarly, the material handling system may include a scanning element for scanning product identification markings on the products. By way of example, an item may be marked with one or more of a variety of markings. Various markings may include, but are not limited to, machine readable optical labels such as bar codes (eg, QR or UPC codes), printed alphanumeric characters, or unique graphic identifiers. The scanning station 80 may include a scanner or reader for reading such markings. For example, a bar code reader, optical reader or RFID reader may be provided to scan the item and read the identification markings.

[0066] The reader may be a portable device that can be manually operated by an operator, such as a portable laser scanner, a CCD reader, a bar code wand or a camera-based detector. These devices scan an image of an item, analyze the image data, and attempt to identify product identification markings. In this manner, an operator may manipulate the item and / or the detection device to scan the identification markings on the item. Alternatively, the scanner or reader may be a built-in scanner, such as any of the devices described above that are incorporated into induction station 50, and the item is simply conveyed over, across or past the built-in reader and the product identification marking is read. With such a device, an operator may pass items over the scanner, or items may be transported automatically through the scanner.

[0067] Once the product identification markings have been determined (either manually or automatically), the material handling system retrieves information about the product and controls further processing of the item based on the information stored in a central database.

[0068] From the foregoing, it will be appreciated that a variety of different input mechanisms may be used to attempt to determine the product identification markings on an item. In this case, scanning station 80 includes one or more optical readers capable of scanning items to obtain optical image data of the items. The material handling system then processes the optical image data to detect the presence of product identification markings. If a product identification marking is detected, the material handling system analyzes the marking to determine the product identification number or code.

[0069] For example, as shown in the embodiment of Figures 1-2 and 4, scanning station 80 may include a number of optical imaging elements 85, 88, such as digital cameras, positioned along transport conveyor 70. The optical imaging elements 85 , 88 are spaced apart from one another and positioned around the periphery of the transport conveyor 70 such that the optical imaging elements 85 , 88 can scan different sides of the items as they are conveyed to the loading station 310 . In particular, scanning station 80 includes one or more cameras 85 oriented along a horizontal axis to scan the front and back of an item. In particular, scanning station 80 may include a plurality of optical imaging elements 85 positioned along a leading end of transport conveyor 70 and a plurality of optical imaging elements positioned along a trailing end of transport conveyor 70 . Additionally, scanning station 80 may include one or more cameras 88 oriented along a vertical axis to scan the top of the items as they are transported along transport conveyor 70 . Additionally, additional imaging elements may be provided that scan the leading and trailing surfaces of the items as they are carried by the transport conveyor 70 . Additionally, the transport conveyor 70 may include a transparent surface over which the items are transported so that the bottom surface of the items can be scanned at the detection station. As such, the scanning station 80 may include an array of sensors, reading elements, scanning elements or detectors positioned around the path of travel such that the scanning station 80 can automatically scan an item's identifying markings as the item is transported along the path.

[0070] As mentioned above, the scanning station 80 may analyze each item and attempt to find product identification markings and identify the item based on the markings. Once the product identity has been determined, the material handling system may then determine a destination for each item, and the items may be electronically tagged to qualify them for sorting. Similarly, parameters for how the haul vehicle 200 should handle the items may also be determined based on information stored in the database for each product code. Conversely, an item may be electronically tagged such that if the item is not determined by a product identifier, it will not qualify for sorting.

[0071] In addition to analyzing items to find product markings, the scanning station 80 may include one or more elements that can evaluate, analyze or measure physical characteristics of the items and determine how the items should be processed. For example, the scanning station 80 may include a scale for measuring the weight of an item. If the detected weight is greater than the threshold, the material handling system may then electronically tag the item to require special handling during subsequent processing. For example, if the weight exceeds a threshold, the material handling system may control subsequent processing to ensure that the item is not discharged into a destination bin containing fragile items. Alternatively, if the weight exceeds a threshold (different from the threshold mentioned above), the item may be tagged as not eligible for sorting. Similarly, scanning station 80 may include one or more detectors for measuring linear dimensions for each item. For example, the scanning station 80 may measure the length, width, and / or height of each item. If one of the dimensions exceeds a predetermined threshold, the material handling system may then electronically tag the item as requiring special handling during subsequent processing. The material handling system may measure one or more linear dimensions of items within the scanning station 80 using any of a variety of elements. For example, a material handling system may use beam sensors (such as an I / R emitter and an opposing I / R detector) to detect leading and trailing edges of an item. Based on the known speed of the transport conveyor 70, the length of the item can be measured. Similarly, the beam sensor may be oriented generally toward the water at a location a predetermined height above the transport conveyor 70 . In this manner, if an item interrupts the beam sensor and thus the item's height exceeds a predetermined threshold, the material handling system electronically tags the item as ineligible for sorting.

[0072] Additionally, the operator may use an input mechanism to identify items as not qualifying for sorting because their physical characteristics exceed a predetermined threshold. For example, scales may be marked on the input conveyor 55 and if an operator visually determines that an item is too long, too wide or too tall, the operator may press a button indicating that the item has physical characteristics that exceed acceptable thresholds and the item may be electronically tagged as ineligible for sorting. Similarly, measurement gauges can be used to assess physical characteristics of items. One type of measurement gauge is a tunnel or chute 60 having multiple spaced apart sides. If the item does not fit between the walls of the chute 60, the item is electronically tagged as exceeding the permitted height, length or width and not eligible for sorting.

[0073] As mentioned above, scanning station 80 may be configured to analyze each item and detect various characteristics of the item as it passes through the scanning station. The material handling system may make a qualification decision based on one or more characteristics detected or determined by the material handling system. If the item does not qualify for sorting, the item may be directed to a discard area 325 to await further processing.

[0074] Typically, items directed to the disposal area 325 are then manually processed. An operator picks up each part, identifies the part, and transports the item to the appropriate destination. Manual processing of discarded items is time consuming and labor intensive, so it is desirable to reduce the number of items heading to the discard area 325. Many of the items headed for Disposal Area 325 may have simply been mis-scanned. It may be that there is not enough identifying information and the item was not sorted, but the necessary information can be read during the next scan.

[0075] Because it may be desirable for some unqualified items to be reprocessed, information detected during the qualification determination may be used to identify different classifications of unqualified items. The first type of ineligible items are waste items headed for the waste area 325 . In the following discussion, these items will be referred to as waste items. The second type of unqualified item is one that is not qualified for sorting but is qualified for reprocessing. In the following discussion, these items will be referred to as reprocessing items.

[0076] The decision to tag an item for disposal, reprocessing, or sorting may be made based on a variety of characteristics. In this case, the decision to tag an item as discarded is made based on the physical characteristics of the item. In particular, if an item does not qualify due to physical characteristics (e.g., has a linear dimension such as height, width or length that exceeds a threshold), the material handling system electronically tags the item as a waste item and the item is directed to the waste area 325 for manual processing. Similarly, if the scanning station 80 includes a scale, the item will be tagged as discarded if the weight exceeds a weight threshold. On the other hand, if an item qualifies based on physical characteristics but the product identification element cannot be identified, the product identification element is electronically tagged for reprocessing so that the item can be reprocessed and an attempt made to read the product identification information. For example, the orientation of the product may prevent the optical imaging elements 85, 88 from properly reading a bar code or other identifying mark. However, because the scanning station 80 has determined that the item meets the physical parameters for processing the item, the material handling system may transport the item to an alternate destination, such as a container for receiving the item to be reprocessed. Items that are sorted or transported to a reprocessing bin may be manually returned to induction station 50 so that an operator can reload the items. Alternatively, the material handling system may convey such items through the material handling system to a redirection assembly. The redirection assembly returns the items to the input conveyor 55 of the guidance station 50.

[0077] In this manner, the material handling system 10 analyzes the item, determines one or more characteristics of the item, and determines whether the item is eligible for transport or whether the item needs to be diverted to ensure that the transport vehicle 200 does not transport the item through the system. In doing so, the material handling system can minimize losses to items and the material handling system that would occur if an item that is oversized or overweight were to be transported or attempted to be transported along the track 110 by one of the transport vehicles 200. Additionally, if an item qualifies for transport but does not qualify for sorting, the item may be transported to a redirection station 430 where an attempt is made to reprocess the item as discussed below.

[0078] As can be appreciated from the above, induction station 50 may be configured in a wide range of options. The options are not limited to the configurations described above and may include additional features.

[0079] Furthermore, in the foregoing description, the material handling system has been described as having a single induction station 50. However, it may be desirable to incorporate multiple induction stations 50 located along the material handling system 10. By using multiple induction stations 50, the part transport speed is increased. Additionally, induction station 50 may be configured to process different types of items.

[0080] 1-3, induction station 50 includes a transfer conveyor 70 that continuously supplies items to loading station 310. A loading station 310 is a location along the track 110 that provides an entrance for loading items onto the haul vehicle 200 . At the loading station 310 , the transport vehicle 200 is positioned along the transport conveyor 70 and items discharged from the transport conveyor 70 are received onto the transport vehicle 200 located at the loading station 310 . After the items are loaded onto the transport haul vehicle 200, if the items have been electronically tagged to qualify for transportation, the transport haul vehicle 200 moves away from the loading dock 310. The other transport vehicle 200 then moves to the loading dock 310 location to pick up the next item. If the item is not electronically tagged to qualify for transportation, the item is discharged from the transport vehicle 200 into a waste receptacle 325 .

[0081] The waste container 325 is located opposite the transport conveyor 70 of the induction station 50 . Additionally, waste containers 325 are positioned alongside the transport vehicles 200 waiting at the loading dock 310 . In this manner, a clear path is provided from the guide station 50 to the waste receptacle 325 without requiring movement of the haul vehicle 200 along the track 110 . <Redirection Assembly>

[0082] 4-6, an alternative embodiment of a material handling system is illustrated. In that embodiment, the material handling system includes an optional redirection system for items that qualify for transport but not for sorting. 4-5, details of the guidance station 50 and redirection system are shown without details of the sortation station 100, such as the output bins 190 and the tracks 110. In FIG. Items that are eligible for transport may leave the loading station 310 and be transported to either the redirection station 430 or the sortation station 100. In particular, a transport vehicle 200 carrying an item that is eligible for transportation moves upward along the track 110 onto the upper rail 135 . If the items on the haul vehicle 200 are tagged for reassessment, the haul vehicle 200 then moves along the track 110 to a redirection station 430 . The haul vehicle 200 then discharges the items onto the redirection assembly 410 . The redirect assembly 410 conveys the item back onto the redirect conveyor, and the item can be reprocessed within the redirect assembly 410 to attempt to qualify the item for sorting.

[0083] The redirection assembly 410 provides a pathway between the track 110 and the guidance station 50 and facilitates the return of the reassessed items to the guidance station 50 . The redirection assembly 410 may include any of a number of transport mechanisms. The mechanism may be driven or stationary, motorized or non-motorized. In this case, however, the redirection assembly 410 includes a roller bed 440 that is angled downward to facilitate rolling of items along the roller bed 440 . In particular, roller bed 440 has an upper end at redirection station 430 . The redirection station 430 is located vertically higher than the lower end of the roller bed 440 so that when an item is discharged onto the upper end of the roller bed 440 at the redirection station 430, gravity tends to impart a force along the roller bed 440 to the item.

[0084] The redirection assembly 410 includes a plurality of end guide members 450 that extend upwardly from and along the ends of the roller bed 440 . A transverse wall extends across the lower end of roller bed 440 between the end guides to form an end wall 460 to hold items against the end of roller bed 440 . One of the end guides 450 has a terminal end located away from an end wall 460 forming an access opening 455 at the end of the roller bed 440 .

[0085] The redirection assembly 410 extends from the track 110 to an area adjacent to the guidance station 50 . In particular, an end of the redirection assembly 410 is located adjacent to the input conveyor 55 . Additionally, the end of the redirection assembly 410 is positioned to allow an operator at the input conveyor 55 to easily access items located at the access openings 455 in the roller bed 440 .

[0086] The induction station 50 may include a second scanning element that is used to scan the items to be reprocessed. For example, as described above, scanning station 80 may include an array of optical imaging elements that scan items and acquire image data. The image data is then analyzed to detect the presence of product identification markings. The induction station 50 may also include a portable laser bar code scanner that an operator can use to scan bar codes on items during reprocessing. In this manner, a first detection element is used during a first process and a second detection element is used during reprocessing.

[0087] Induction station 50 may also include an input mechanism that an operator can use to indicate that an item is to be reprocessed. For example, before placing an item from the redirection assembly 410 onto the input conveyor 55, an operator may press a button. The materials handling system then tags the item to indicate that it has been previously processed, and if the materials handling system is unable to legally process the item on a second attempt, the item will be tagged for disposal rather than tagged for reprocessing again. In this manner, items flowing in a manner that would prevent identification do not continue to pass repeatedly through the redirection assembly 410 . Similarly, if a second scanning element is used during reprocessing, the use of the second scanning element may act as a signal that the item is being reprocessed. In other words, when the second element is used to scan the item, the material handling system may tag the item as being reprocessed.

[0088] As mentioned above, the redirection assembly 410 includes a roller bed 440 that uses gravity to carry the items back to the redirection station 50 . It should be understood that, rather than roller bed 440, alternative mechanisms can be used. For example, a chute or a flat ramp may be used. Alternatively, a conveyor belt may be installed to carry the items towards induction station 50. Furthermore, in the above description, the redirection assembly 410 is generally a straight line track. However, it should be understood that the redirection assembly 410 may incorporate a bend or corner such that the discharge end of the redirection assembly 410 is positioned adjacent the input conveyor 55 of the induction station. Further, in FIGS. 4-5 and the above description, redirection station 430 is located in the column next to loading column 300. However, it should be understood that the redirection station 430 and associated conveyor 440 may be located in other columns, including the loading column 300. <Sorting area>

[0089] Items that are qualified for sorting by induction station 50 are transported by transport vehicle 200 to sorting station 100. 1-6, a material handling system includes a sortation station 100, such as a row of output bins 190 for receiving parts.

[0090] The track 110 includes a horizontal upper rail 135 and a horizontal lower rail 140 . A number of vertical sections 130 extend between an upper horizontal section and a lower horizontal section 140 . During transportation, the transport vehicle 200 moves up a set of vertical sections from the loading dock 310 to the upper rails 135 . The delivery vehicle 200 then travels along the upper rail 135 until it reaches the appropriate output bin 190 or column having the destination. The transport vehicle 200 then travels downward along the two front vertical columns and two parallel rear columns until it reaches the appropriate output bin 190 or destination, and then ejects the items into the output bin 190 or destination area. The haul vehicle 200 then continues down the vertical section until it reaches the lower horizontal section 140 . The transport vehicle 200 then travels back along the lower rail 140 towards the loading dock 310 .

[0091] The track 110 includes a front track 115 and a rear track 120 . The front and rear tracks 115 , 120 are parallel tracks that cooperate to guide the haul vehicle 200 around the track 110 . As shown in FIG. 7, each of the haulage vehicles 200 includes four wheels 220: two front wheels 220A and two rear wheels 220B. The front wheels 220A ride on the front track 115 while the rear wheels 220B ride on the rear track 120. In discussing the track 110 , it should be understood that the front track 115 and the rear track 120 are opposing tracks 110 that are similarly configured and support the front wheels 220 A and rear wheels 220 B of the transport vehicle 200 . Thus, any discussion of any portion of either the forward or rearward track also applies to the opposing forward track 115 or rearward track 120 .

[0092] 1 to 3, the loading column 300 is formed adjacent to the output end of the induction station 50. The loading column 300 is formed by a front set of vertical rails 305a, 305b and a corresponding rear set of vertical rails. Loading stations 310 are located along the loading column 300 . The loading station 310 is a location along the track 110 where the transport vehicle 200 is positioned along the discharge end of the transport conveyor 70 at the guidance station 50 . In this manner, the items may be loaded from the induction station 50 onto the transport vehicle 200 as the items are transported from the input station to the vehicle.

[0093] The details of the track 110 are substantially similar to the track 110 described in US Pat. No. 7,861,844. The entire disclosure of US Pat. No. 7,861,844 is incorporated herein by reference.

[0094] In accordance with the above description and with reference to FIG. 3, the track includes multiple vertical sections extending between horizontal upper and lower rails 135 and 140 . At each point in the trajectory 110 where one of the vertical segments intersects with one of the horizontal segments, a crossover point is formed. Each intersection includes a pivotable gate having a smoothly curved inner race and a flat outer race having teeth that correspond to the teeth on the drive surface for the track 110 . The gate pivots between a first position and a second position. In the first position, the gate is closed so that the straight outer race of the gate follows the straight outer branch of the intersection. In the second position, the gate is open so that the curved inner race of the gate follows the curved branch of the intersection.

[0095] In the above description, sortation station 100 is described as having a number of output bins 190 . However, it will be understood that the material handling system may include various types of destinations other than simply output bins 190 . For example, in certain applications it may be desirable to separate items into storage areas, such as areas on a storage shelf. Alternatively, a destination may be an output device that transports the items to another location.

[0096] Output bin 190 may be a generally rectilinear container having a base, two opposing sides connected to the base, and a front wall connected to the base and spanning between the two sides. The output bin 190 also has a rear wall opposite the front wall, connected to the bottom surface and spanning two sides. In this manner, output bin 190 may resemble a rectangular drawer that can be pulled out of sorter station 100 to allow items to be removed from the bin.

[0097] The output bins 190 in a column are spaced vertically apart from one another with gaps between adjacent output bins 190 . The larger gap provides more clearance space for the transport vehicle 200 to discharge items into the lower output bin without interference between the items and the upper output bin 190. However, the larger gap also reduces the number of output bins 190 and the size of the output bins 190 (ie, the density of the output bins 190). Thus, a compromise exists between gap size and output bin 190 density.

[0098] The transport vehicle 200 discharges items into the output bin 190 through the rear end of the output bin 190 . Thus, if the back of the output bin 190 is open, the transport vehicle 200 can easily discharge items into the output bin 190 through the open rear end of the output bin 190 . However, if the output bin 190 does not have a trailing edge, items may tend to fall out of the output bin 190 as the output bin 190 is being withdrawn from the sortation rack. Thus, depending on the application, output receptacle 190 may have an open or closed rear end. If the rear end is closed, the rear wall may be the same height as the front wall. Alternatively, the rear wall may be shorter than the front wall, providing a larger gap through which items can be discharged into the output bin 190 . For example, the rear wall may be only half the height of the front wall. Optionally, the rear wall may be between one-quarter and three-quarters the height of the front wall. For example, the rear wall may be between one-half and three-quarters the height of the front wall. Alternatively, the rear wall may be between one-quarter and three-quarters the height of the front wall.

[0099] Alternatively, rather than having a fixed back wall, output bin 190 may have a movable or collapsible back wall. For example, the rear wall of the output bin 190 may be removable perpendicular to the bottom surface of the output bin 190 . In particular, the rear wall may be removable by pushing the wall downwards. The rear wall is removable within a groove or slot formed in the side wall of the output bin 190, and by pushing the rear wall downward, it may be removed downward such that a portion of the rear wall protrudes below the bottom surface of the output bin 190. In such an embodiment, the rear wall may be biased upwardly by a biasing element, such as a spring, to tend to cause the rear wall to remain in an upper position with its rear lower end above the lower end of the output bin 190. The rear wall moves only downward in response to a force that exceeds the upward biasing force on the rear wall.

[0100] Meanwhile, other alternative output bins incorporate a collapsible back wall. Like the removable wall, the collapsible wall moves downwardly by applying a downward force against the collapsible wall. The collapsible walls can have a variety of configurations, such as an accordion or pleated configuration, such that the walls fold downward when a downward force is applied. The collapsible wall may include a biasing element that biases the wall upwardly into the extended position. For example, the biasing element may include one or more springs or resilient elements that bias the wall upwardly into the extended position.

[0101] As mentioned above, the material handling system operates to allow sorting of a variety of items into multiple destinations. One type of destination is an output bin 190, a second type is a shelf or other location where items are stored, and a third type of destination is an output device used to transport items to a different location. A material handling system may include one or more of each of these or other types of destinations. <Transport vehicle>

[0102] Each haul haul vehicle 200 is a semi-autonomous vehicle having an on-board drive system that includes an on-board power supply. Each haul vehicle 200 includes mechanisms for loading and unloading items for transport. An embodiment of a haul vehicle 200 operating in conjunction with the material handling system 10 is shown and described in US Pat. No. 7,861,844, which is incorporated herein by reference. However, an alternative haul vehicle 200 is shown in FIG. The haul vehicle 200 includes additional sensors for detecting characteristics of the items being hauled.

[0103] The haul vehicle 200 may incorporate any of a variety of mechanisms for loading items onto the haul vehicle 200 and unloading items from the haul vehicle 200 into one of the receptacles. Additionally, the loading / unloading mechanism 210 may be specially tailored for a particular application. In this case, however, the loading / unloading mechanism 210 is one or more conveyor belts 212 that extend along the top surface of the transport vehicle 200 . The conveyor belt 212 is reversible. Driving the conveyor belt in a first direction moves items toward the rear end of the transport vehicle 200 and driving the belt in a second direction moves items toward the front end of the transport vehicle 200.

[0104] A conveyor motor mounted on the underside of the transport vehicle 200 drives the conveyor belt 212 . In particular, the conveyor belt 212 is trained around front rollers at the front end of the transport vehicle 200 and rear rollers at the rear end of the transport vehicle 200 . A conveyor motor is coupled to the front rollers and drives the front rollers, thereby moving the conveyor belt 212 .

[0105] The transport vehicle 200 includes four wheels 220 that are used to transport the transport vehicle 200 along the track 110 . The wheels 220 are mounted on two axles 215 spaced apart and parallel to one another, with two of the wheels 220 positioned along the front end of the transport vehicle 200 and two of the wheels 220 positioned along the rear end of the transport vehicle 200.

[0106] Each wheel 220 has an outer gear that cooperates with a drive surface of the track 110 . The outer gear is fixed relative to the axle 215 on which it is mounted. Thus, rotating the axle 215 causes the gears to rotate. Thus, as the haul vehicle 200 moves vertically, the gears cooperate with the drive surfaces of the track 110 to move the haul vehicle 200 along the track.

[0107] The transport vehicle 200 includes an on-board motor for driving the wheels 220 . In particular, the drive motor is operatively coupled to the axle 215 to rotate the axle 215 , which in turn rotates the gears 222 of the wheels 220 .

[0108] As the haul vehicle 200 moves along the track 110, items on the haul vehicle 200 may be prone to falling off the haul vehicle 200, especially as the haul vehicle 200 accelerates and decelerates. Thus, the transport vehicle 200 may include a holding portion to hold the element on the transport vehicle 200 during transport. The retaining portion may be a fastener that clamps the item against the top surface of the transport vehicle 200 . For example, the holder may include a pivotable extension arm. A biasing element, such as a spring, may bias the arm downwardly against the upper surface of the retaining portion.

[0109] Alternatively, rather than using a holddown, the material handling system may hold items on the transport vehicle 200 by controlling the movement of the transport vehicle 200 . For example, the haul vehicle 200 may include multiple sensors 230 spaced apart across the width of the haul vehicle 200 . In the embodiment shown in FIG. 7, multiple sensors 230 are spaced apart along a leading wall 231 of the haul vehicle 200 . The leading wall 231 may be an extension element that extends across the width of the transport vehicle 200 . The leading edge wall 231 acts as a catch or restraint to restrict items from falling or being ejected out of the leading edge of the transport vehicle 200 . Similarly, the haul vehicle 200 may include a rear end wall 232 that extends across the width of the haul vehicle 200 . The rear end wall 232 acts as a catch or restraint to restrict items from falling or being ejected out the rear end of the transport vehicle 200 . The haul vehicle 200 may also include a number of sensor elements spaced apart from one another along the rear end wall 232, which sensor elements are similar to the sensor 230 shown on the leading end wall 231 in FIG. Sensor 230 may be any of a variety of sensors, including, but not limited to, a photoelectric sensor (such as a counter passing beam sensor or a retroreflective sensor) or a proximity sensor (such as a capacitive, photoelectric, or inductive proximity sensor). Such sensors 230 are used to detect the location of items across the width of the haul vehicle 200 . In particular, the sensor 230 can detect how close an item is to the front 234 or rear 236 of the haul vehicle 200 . Similarly, if the sensor 230 is a proximity sensor, the sensor 230 can detect how close an item is to the leading end of the transport vehicle 200 (i.e., leading wall 231) and / or the trailing end of the transport vehicle 200 (i.e., trailing wall 232). Additionally, the sensor 230 can detect movement of items on the transport vehicle 200, and if an item is moving on the transport vehicle 200, the material handling system can detect the direction the item is moving.

[0110] Based on signals from the sensor 230 regarding the position or movement of items on the transport vehicle 200, the material handling system may control the transport vehicle 200 to reposition the items and attempt to maintain the items within the desired position on the transport vehicle 200. For example, it may be desirable to keep items generally centrally located on the top surface of the transport vehicle 200 . The material handling system can control the position of items on the haul vehicle 200 using any of a variety of controls. For example, as previously mentioned, the haul vehicle 200 may include one or more conveyor belts for loading and unloading items. In such a configuration, an item may remain on the conveyor belt and, based on a signal received from the sensor 230, the conveyor belt may drive the item toward either the leading end 234 or the trailing end 236. In one embodiment, if a signal from the sensor 230 indicates that an item is moving closer to the back end 236 than to the front end 234, the controller can send a signal to a motor to drive the conveyor belt, causing the conveyor belt to move in a first direction and move the item toward the front end 234. Similarly, if the signal from the sensor 230 indicates that the item is moving closer to the leading end 234 than to the trailing end 236, the controller can signal the motor to drive the conveyor belt, which can move in a second direction to move the item in the opposite direction, thereby moving the item toward the trailing end 236. The sensor 230 provides continuous feedback so that the position of the item is continuously monitored and the position of the part can be adjusted towards the leading end 234 or the trailing end 236 as the item moves. In this manner, the material handling system provides a feedback loop to provide real-time adjustments to the position of the items to keep them within the desired area on top of the transport vehicle 200.

[0111] Additionally, the material handling system can monitor the position of items relative to the front end 234 and rear end 236 of the transport vehicle 200 (such as leading wall 231 and trailing end wall 232). Depending on the detected position of the element, the material handling system can control the operation of the haul vehicle 200 if the item is too close to the leading end or too close to the trailing end 236 . In particular, the material handling system may control the acceleration and deceleration of the transport vehicle 200 to attempt to move items towards the leading or trailing end 236 based on the detected position. If the sensor 230 detects that the item is located closer to the front end than the rear end 236, the transport vehicle 200 may be accelerated (i.e., the acceleration may be increased), thus urging the item toward the rear end 236. Alternatively, the haul vehicle 200 may be decelerated, urging the items towards the tip.

[0112] In addition to ascertaining or monitoring the location of items on the haul vehicle 200, the sensors 230 may be used to detect one or more characteristics of the items. For example, the sensor 230 may be used to detect the width dimension of an item. The sensor 230 is also used to detect the general shape of the item. This information can be used during further processing of the item, as discussed further below.

[0113] As mentioned above, the output bin 190 may include a removable or collapsible rear wall. Thus, the transport vehicle 200 may include a mechanism for applying a downward force to the rear wall sufficient to overcome the biasing force holding the rear wall in an upward or upright position. For example, the transport vehicle 200 may include an extendable element, such as a pin or rod. As the delivery vehicle 200 approaches the target delivery container, the pins may extend laterally, away from the delivery vehicle 200, so that the pins extend beyond the rear wall of the target container. As the transport vehicle 200 approaches the output bin, the extended pin engages the upper edge of the rear wall of the output bin. Moving the transport vehicle 200 downwardly causes the pin to move downwardly towards the rear wall. The material handling system may control the vertical position of the transport vehicle 200 and may control the rate at which the transport vehicle 200 is pushed downwards and the rear wall collapses. After the transport vehicle 200 has discharged the items into the receptacle, the extensible element may retract, thus releasing the rear wall, and the biasing element may bias the rear wall upwardly to an upper position.

[0114] Haul vehicle 200 may be powered by an external power supply, such as contacts located along the rails, that provides the power necessary to move haul vehicle 200. In this case, however, the haul vehicle 200 includes an on-board power supply that provides the necessary power for both the drive motor and the conveyor motor. Moreover, in this case the power supply is rechargeable. The power supply may include a power source such as a rechargeable battery, but in this case the power supply is made up of one or more ultracapacitors.

[0115] As discussed further below, haul vehicle 200 further includes a processor that controls operation of haul vehicle 200 in response to signals received from the central processor. Additionally, the haul vehicle 200 includes a wireless transceiver, allowing the haul vehicle 200 to communicate continuously with the central processor as the haul vehicle 200 travels along the track 110 . Alternatively, in some applications it may be desirable to incorporate multiple sensors 230 or indicators positioned along the track 110 . The haul vehicle 200 may also include a reader for sensing sensor signals and / or indicators, as well as a central processor. The central processor controls the operation of the haul vehicle 200 in response to the sensors 230 or indicators. <Edge detection system>

[0116] As mentioned above, the material handling system 10 may include one or more elements for detecting items on the haul vehicle 200. It may also be desirable to detect leading and trailing ends 236 of items as they are loaded onto or unloaded from the transport vehicle 200 . Thus, each haul vehicle 200 may include one or more sensors that detect items on the haul vehicle 200 .

[0117] In the embodiment shown in FIG. 7, each haul vehicle 200 may include multiple detectors 230 that detect items on the haul vehicle 200 (ie, on the surface of the conveyor belt 212). One of the leading edge sensors 230A may be located near the leading end 234 and may detect items as they are being loaded onto or unloaded from the leading end 234. Similarly, one of the sensors 230B may be located near the back end 236 and may detect items as they are loaded onto or unloaded from the back end 236. For example, leading edge sensor 230A may be a beam break sensor such that the beam is broken when an item passes in front of it. As an item is loaded onto the transport vehicle 200, the leading edge of the item will interrupt the beam. This indicates that the leading edge of the item is on the transport vehicle 200 . The item may continue to obstruct the leading edge sensor 230A until the trailing end 236 of the item passes the leading edge sensor 230A. After the trailing end 236 of the item passes the leading edge sensor 230A, the leading edge sensor 230A no longer detects the item. This indicates that the item is being loaded onto the transport vehicle 200 . After the trailing end 236 passes the leading end sensor 230A, the conveyor belt 212 may continue to move the item toward the trailing end 236, ensuring that the item is centered along the width of the transport vehicle 200. Similarly, as an item is discharged from the leading wall 231 of the transport vehicle 200, the leading sensor 230A may detect the leading and trailing ends 236 of the item. Detection of the trailing end 236 passing the leading edge sensor 230A may be used to signal that the item has been ejected from the haul vehicle 200. The transport vehicle 200 is then prompted to move in a direction away from the discharge site. The above description of the use of leading edge sensor 230A to detect leading and trailing edges 236 of items being loaded onto or discharged from leading edge 234 is equally applicable to the use of trailing edge sensor 230B to detect leading and trailing edges 236 of items as they are loaded onto or discharged from the trailing edge 236 of the transport vehicle 200.

[0118] In the above description, the sensor 230 detects items being loaded into and unloaded from the front end 234 or rear end 236 of the haul vehicle 200 . In certain applications, it may be desirable to incorporate sensing assemblies that detect a greater variety of items. For example, when using a beam break sensor, it may be difficult to detect the leading or trailing edge 236 of an item if the item is very thin or if the item is transparent or translucent. Thus, the material handling system may incorporate an alternative sensing arrangement, shown generally at 500 in Figures 8-12. The sensing and positioning mechanism 500 is described in connection with the transport vehicle 200 of the material handling system 10 . However, it should be understood that the sensing arrangement 500 may be incorporated into other aspects of a material handling system such as detecting items as they pass along the induction station 50 . Additionally, the sensing arrangement 500 described below may find further application in endeavors outside of the material handling field, including but not limited to fields such as mail handling or document handling.

[0119] Embodiments of the edge sensing assembly include material handling systems and methods to aid in reliable and accurate detection of when a leading and / or trailing edge of an object supported by an underlying conveyor surface crosses a detection surface. According to one or more embodiments, the detection plane is defined by optical energy. Optical energy is emitted by a laser and collimated by a lens system to form a diverging beam of constant width that propagates within the detection plane. The linear array of detectors 506 is maintained aligned along the lens system so that any object crossing the detection plane is impinged with collimated optical energy at an unusual angle of incidence.

[0120] Conventional "cross-beam" sensors can have difficulty detecting transparent, thin and / or irregularly shaped objects. However, in accordance with one or more embodiments consistent with this disclosure, such objects are readily sensed by changes in the intensity of optical energy detected by one or more detectors 506 in the array. For example, in the presence of an optically opaque object, optical energy will be absorbed and at least one detector 506 will sense a decrease in light intensity. Alternatively, for objects that include optically transparent parts and / or packaging, some light may be transmitted and some light may be reflected or refracted. This causes at least one detector 506 to sense a small but detectable decrease in light intensity. Even relatively thin objects (on the order of 0.05 mm) can be reliably detected with proper placement of the lens system and detector 506 .

[0121] Various embodiments of lens systems and methods are described for detecting the crossing of a detection surface by a leading and / or trailing surface of an object supported by an underlying conveyor surface. Numerous details are set forth in the following detailed description to provide a thorough understanding of claimed subject matter. However, it will be understood by one skilled in the art that claimed subject matter may be practiced without these details. In other instances, methods, apparatus or systems known from one of the prior art have not been described in detail to avoid obscuring the claimed subject matter.

[0122] The edge detection assembly 500 includes one or more emitters 504 that emit a light source and one or more detectors 506 that detect the emitted light. At least one emitter 504 is positioned below an object support surface S that supports an item. For example, in the embodiment illustrated in FIG. 10, the emitter 504 is positioned vertically away from the location of the object support surface S such that it is below the plane of the object support surface S. In this example, the plane of the object support surface S is a horizontal plane and the emitter 504 is below the object support surface. Thus, the light emitter from emitter object support 504 extends at an angle perpendicular to the plane of object support surface S. By projecting the emitted light at an angle to the object support surface S, the object can have a larger surface onto which the emitted light impinges than if the light were emitted parallel to the object support surface S. For example, in the case of a sheet of paper resting on an object support surface S, if light from emitter 504 is emitted parallel to the object support surface S, only the lateral edges of the paper will reflect or block the light from emitter 504. The lateral edges of the paper may be so thin (such as 0.05 mm) that it would be difficult or impossible to detect using an emitter 504 that emits light parallel to the object support surface S. However, by lowering the emitter 504 below the object support surface S and emitting light at an angle to the object support surface S, the entire width of the paper can reflect light from the emitter 504.

[0123] Turning now to FIG. 8, object sensing assembly 500 is adapted to sense when an object boundary surface (e.g., the leading or trailing end of an object positioned on an underlying object support surface S) crosses within a detection plane or "curtain" 502 of light emitted by emitter 504 (also referred to as an emitter). A linear array of detectors 506 (generally designated 508) are arranged along the emitter 504, and unless an object is present within the detection surface 502, the emitted light strikes each of the detectors 506 without any reduction in intensity.

[0124] In some embodiments, emitter 504 is a fixed laser that emits a beam of coherent light in the wavelength range visible to the human eye. Emitter 504 may be a laser that emits light at or near the peak sensitivity of detector 506 in order to efficiently and reliably detect its output. According to one embodiment, the detector 506 is a phototransistor and may have, for example, a spectral range of sensitivity within the frequency range between 350 and 900 nm and a peak sensitivity of 560 nm. One such phototransistor is the SFH3710 manufactured by Osram Opto Semiconductors GmbH of Regensburg, Germany. However, it should be noted that other detectors, such as, for example, a photodiode, may be employed in place of detector 506 . Where appropriate, the effect of ambient light on the sensitivity of the detector 506 can be addressed by placing a bandpass filter over the columns 508 to prevent light outside a narrow range centered around the peak sensitivity from reaching the detector 506.

[0125] Emitter 504 may comprise a single laser with an integrated lens system that includes one or more collimating lenses, such as lens 522 . Lens 522 is sized and positioned to receive the optical energy emitted from the laser source and is sized and positioned to collimate the received optical energy such that the light beam diverges within curtain 502 along a major axis but not along a minor axis. As can be seen in both FIGS. 8 and 9A, the collimated emission of emitter 504 propagates within curtain 502 and forms a line or area 550 that spans each of detectors 506 in linear array 508 . Even thin, optically transmissive (e.g., translucent) or highly reflective objects can be detectable if the collimated output of the light source 504 strikes the object at an oblique angle, the multiple detectors 506 are spaced apart from one another, and the multiple detectors 506 are positioned at an elevated position relative to where the light enters and / or where the light reflects off the object.

[0126] For example, from the perspective view of FIG. 8, by using a light curtain 502 having a width of approximately 25-35 cm and a height of approximately 10-20 cm, the assembly can detect objects having a thickness between 0.05 mm (i.e., the thickness of a sheet of paper) and approximately 10 cm, and a width on the order of approximately 7.5 cm to approximately 30.5 cm. Such detection can be accomplished using a 1 mW laser with integrated collimating optics. With a fan angle of 20 degrees and a beam divergence of less than 2 milliradians (mRads), such a laser can project a 5 cm line with a width of 1 to 2 mm. When positioned near, but slightly below, the discharge end of the object support surface S, the light source 504 and the array 508 define a detection plane that is transverse to and perpendicular to the plane defined by the object support surface S. In some embodiments, the object supporting surface S may be the moving surface of a conveyor belt. In other embodiments, the object supporting surface S may be a stationary or tilted table surface.

[0127] Depending on the components that make up the collimating lens system, the intensity of the light in line 550 in FIG. 9A may not be constant across all detectors 506 when no objects are present to block the intensity of the light curtain 502 . Alternatively, the intensity across the light curtain 502 may vary according to a Gaussian or other expected distribution function. In either case, embodiments consistent with this disclosure are configured to detect changes in the light intensity received by any of multiple detectors 506 as an object crosses (or leaves) the light curtain 502. That is, when an amount of optical energy exceeding a sensitivity threshold is absorbed, reflected, or refracted by an object on the object support surface S, the output of at least one of the detectors 506 in the array 508 transmits a signal indicating a change in state.

[0128] In an embodiment in which the sensing and placement mechanism 500 forms part of a material handling system, the detected change in state of the detector 506 may be used to confirm that the object has been successfully delivered to a storage or packaging location, or to confirm that the object has been successfully retrieved from a storage or pick-up location. Conversely, the failure to detect a signal indicative of a change of state may also be used to control operations within a material handling system or other system. For example, the failure to indicate a change in status after a predetermined "timeout" interval may be used as part of an alert sequence (eg, triggering an audible or visible alert to a human operator).

[0129] One possibility for increasing the range of light detected by the detectors 506 would be to use a complementary set of detector 506 arrays and light sources to increase the area of ​​the light curtain 502 . However, it will be appreciated that equivalent results can be achieved by bending the path of the light in the arrangement of FIG. 8 using a reflector 516. In such an arrangement, the detectors 506 in the row 508 may optionally be mounted along with the emitters 504 to a first fixed support 510 to form an integrated emitter / detector assembly 512 . The reflector 516 may be attached to a second fixed support 518 . The first support 510 and the second support 518 may be fixedly connected, for example, by a support shaft 520 extending between the two supports. The support shaft 520 may be resiliently biased to maintain the orientation of the light curtain 502 relative to the surface S, while allowing the angle of the light curtain 502 to be temporarily repositioned in response to transportation of the object support surface S.

[0130] In some embodiments, the detector 506 and the light source 504 may be mounted on a common substrate 524, such as, for example, a printed circuit board. The collimated diverging beam emanating from lens 522 of emitter 504 is reflected by face 530 (FIG. 9B) of reflector 516 to form a projected line or area 550 that covers array 508 of detector 506 . In applications where the objects being treated are expected to have a variety of heights, ranging from less than 1 mm to more than 20 cm, the line 550 may have a width W, for example, on the order of about 1 mm to about 5 mm, and a length L, for example, on the order of 10 cm to 20 cm. In an embodiment, the rows 508 are configured to provide coverage along the entire length of the line L.

[0131] To enable detection of very thin objects, the detectors 506 in the array that are closer to the object support surface S may be spaced closer together than the detectors 506 that are farther away from the object support surface S. In the embodiment of FIG. 9A, the spacing d1 between the lowest four detectors 506 may be on the order of 1-5 mm, while the spacing d2 between the remaining detectors 506 is on the order of 10-15 mm. Of course, such arrangements are described herein as illustrative examples only. Arrangements such as an arrangement in which the distance between at least one pair of detectors 506 of the multiple detectors 506 increases monotonically with distance from the object support surface S, and / or an arrangement in which the distance between the detectors 506 is constant, are also contemplated within this specification. It is fully appreciated that the number and placement of detectors 506 may be varied without departing from the spirit and scope of the present disclosure.

[0132] FIG. 9B shows a reflector 516 attached to an arm 518, mirroring the support 510 of FIG. 9A, to form an object sensing and positioning mechanism 512 as shown in FIG. As can be seen in FIG. 9B, the reflector 516 defines a substantially flat reflective surface 530 and is secured to a second rigid member 518 . Additionally, as shown in FIGS. 8, 9A and 9B, the height of the row of mirrors 516 upon which the light impinges is substantially less than the height (L) of the rows 508. Thus, the height of the reflector 516 may be substantially less than the height (L) of the row 508 .

[0133] Transverse holes 526a and 526b are defined in each of the first and second rigid members 510 and 518 and may accommodate the insertion of an optional mounting shaft, such as mounting shaft 520 (FIG. 8). For example, in an operating environment in which the sensing and positioning mechanism is fixed to a stationary structure, such as the frame of a conventional belt or roller conveyor, the mounting axis and corresponding cross holes 526a and 526b may be omitted. Additionally, any other structure for positioning the light source, detector 506, and (if applicable) reflector 516 relative to one another and to the object support surface may be employed.

[0134] FIG. 10A illustrates the use of a sensing arrangement such as that shown in FIG. 8 to detect an optically opaque object O. 1 detects an object as it moves along its transport path (eg, on an underlying object support surface S) and crosses a curtain of light (or "detection plane"). A light curtain is defined by the propagation of collimated optical energy in a direction transverse to the transport path of the object. As can be seen in FIG. 10A, the light emitted by optical energy source 504 is collimated by a lens structure that includes lens 522. In this example, object O 1The height and width of emitter 504 are dimensioned such that light from emitter 504 is reflected from reflector 516 and detected by detectors 506-2 through 506-10. However, the object O 1 absorbs most or all of the optical energy reaching detector 506-1, so that detector 506-1 either does not detect light or the light that detector 506-1 detects is below a threshold.

[0135] As described in more detail below, a drop in intensity at detector 506-1 is processed by appropriate sensing logic as a state change (e.g., a logical "1") indicating an object crossing the detection plane defined by the surface of the generated light curtain 502. Similarly, object O 1 When all of the portions of the light exit the light curtain, the intensity of the optical energy received at detector 506-1 returns to its previous state (eg, a logic "0") and a transition occurs to the second state.

[0136] FIG. 10B illustrates the propagation of an object O along a transport path across a detection plane defined by the propagation of collimated optical energy. 2 When the object O moves, the object O includes at least one light refracting or reflecting part. 2 This shows the detection of For example, object O 2 may be a block-like item contained in a transparent or translucent packaging extending beyond its dimensions. Such an object may have opaque parts (eg the block) and transparent or translucent parts (eg the packaging surrounding the block).

[0137] Some of the light emitted by the emitter 506 is incident on the object O. 2 The transparent parts of the image are transparent. And in a configuration where the emitter 506 is parallel to the object support surface S, the light passes through the transparent or translucent portion and the lens system does not detect the object. In this case, the light emitted by the emitter 506 is incident on the object O 2 Object O supports an object O.2 Light passing through a transparent or translucent portion of the detector 506 is refracted and may not impinge on the detector column 508 . For example, referring to FIG. 10B, emitted light propagating along a wave B strikes an object O at an oblique (unusual) angle. 2 would collide with the surface. Some incident light Bink is incident on the object O 2 After impacting the ion beam, it is reflected and / or refracted. object O 2 Depending on the surface properties of the object O, some or all of the reflected incident light may be directed away from the detector, as wave Bref2, while other portions (e.g., wave Bref1) may be directed away from the detector, as all of the light (e.g., along wave Btrans) travels through the object O. 2 If the light passes through the object, it will be reflected into a different detector than if the object had not been there at all. Thus, when a translucent or transparent part of an object refracts light away from the array, The array detects changes in light from the emitters, and the lens system detects the objects.

[0138] As mentioned above, the edge detection assembly 500 may be incorporated into a transport vehicle used in the material handling system 10 described above. For example, turning to FIG. 11, an alternative haul vehicle 600 is illustrated. Haul vehicle 600 is substantially similar to haul vehicle 200 described above. However, the haul vehicle 600 includes one or more end detection assemblies 602, 604 that are similar to the end detection assembly 500 described above.

[0139] Each haul vehicle 600 may include a single object sensing arrangement for sensing object movement in a single direction along the haul path. Alternatively, as shown, each vehicle 600 may include a set of object sensing and positioning mechanisms in the form of detection assemblies 602 and 604 . Each transport vehicle 600 may also include one or more conveyors for transporting objects while they are on the transport vehicle 600. The belts form a generally flat or planar surface for supporting objects on the vehicle 600 . For example, the conveyor 606 may be a conveyor belt. A first detection assembly 602 may be located near the rear end of the transport vehicle 600 with an emitter located below the top surface of the conveyor belt 606 . The detectors of the detection assembly 602 may be located above the surface of the conveyor belt 606 . Additionally, the detection assembly may be positioned proximate the trailing end of the conveyor belt 606, such that the plane of the conveyor belt 606 does not extend between the emitters and detectors of the detection assembly. In this manner, when an object passes over the rear end of the transport vehicle 600 , the object will first pass between the emitter and detector rows of the detection assembly 602 . Similarly, when an object is being discharged from the rear end of the transport vehicle 600, if the leading edge of the item extends past the end of the conveyor, the leading edge of the item will pass between the emitter and the detector row of the detection assembly. Similarly, the front detection assembly 604 is positioned adjacent to the front end of the transport vehicle 600 such that when an object is being loaded onto or unloaded from the tip of the transport vehicle 600, the front detection assembly 604 detects the tip of the object.

[0140] The detection assembly 602 transmits a signal signifying a first change in logic state, as described above in relation to assembly 500, for example, when the object is moved in a first transport direction "A" by the conveyor belt 606 and the leading edge of the object crosses a first light curtain detection surface of the end sensing assembly. Such a signal would indicate the leading edge of an item being discharged from the rear end of the transport vehicle 600 . Similarly, the detection assembly 602 may emit a signal indicating a next (e.g., second) change in logic state when and if the object continues to move in direction A via the conveyor belt 606 and the trailing end of the object exits the first light curtain detection surface. Such a signal would be indicative of the rear end of the object being ejected from the rear end of the transport vehicle 600 , thereby indicating that the item has been ejected from the transport vehicle 600 .

[0141] Similarly, the detection assembly 604 may emit a signal signifying a first change in logic state when the conveyor belt 606 moves the object in the second transport direction "B" and the leading edge of the object crosses a second light curtain detection surface of the end sensing assembly 604. Similarly, the detection assembly 604 may transmit a signal indicating a next (e.g., second) change in logic state when and if the conveyor belt 606 continues to move the object in the second transport direction B and the trailing end of the object exits the second light curtain detection surface.

[0142] The transport vehicle 600 may include side walls that are sized and positioned to prevent movement of objects on the conveyor surface 605 as it moves along a travel path that intersects the transport path direction A and the transport path direction B. Movement of conveyor belt 606 in either transport path direction A or transport path direction B is accomplished in some embodiments by a reversible electric motor 610 that transmits force to conveyor shaft 611 by way of belt 612 . Similar to the operation of haul vehicle 200 described above, separate motors drive multiple wheels (eg, 614a, 614b, 614c) of haul vehicle 600, which engage the tracks.

[0143] FIG. 12 is an electrical schematic diagram illustrating a circuit 650 including a detector and state sensing logic capable of transmitting a signal indicative of a change in sensing state when an object crosses a detection surface or light curtain along which the detector is positioned, in accordance with an embodiment of the present disclosure. In the embodiment of FIG. 12, the detectors are each configured in a common emitter amplifier circuit. NPN phototransistor PT 1 From PT 10 It is being implemented as a.

[0144] The output of each common emitter amplifier is connected to the voltage supply V B and the collector pin of the associated phototransistor. 1 From R 10 ) is generated. Register R 1 From R 10 The value of is chosen to set a detection threshold (eg, to distinguish between expected levels of ambient light in a given installation). A low value for the threshold resistor (several thousand ohms) sets a high threshold that the incident light must exceed before switching occurs (ie, low sensitivity). On the other hand, a high value sets a low (ie, high sensitivity) threshold level. For example, the use of an SFH3710 phototransistor manufactured by OSRAM Opto Semiconductors GmbH of Regensburg, with a voltage VB on the order of 3.0 to 3.5 volts, under conditions typically applicable in an indoor warehouse environment, provides a circuit that is not impaired by noise or interference from ambient light sources such as indoor lighting. 1 From R 10 A resistance value on the order of 300 ohms may be produced. Additionally, a filter (not shown) may also be used that limits the light reaching the phototransistor to a relatively narrow (eg, + / - 2 nm) passband centered around a selected wavelength within the sensitivity envelope of the phototransistor.

[0145] The sensing logic 652 may comprise any arrangement capable of rapidly sensing the output of each detector and signaling and / or processing a change of state indicative of the motion of the light curtain. In one implementation consistent with the embodiment of FIG. 12, the outputs of each phototransistor circuit may be combined using combinatorial logic to output a state change from “0” to “1” by the sensing logic 652 when the output of any one of the phototransistors falls below a sensitivity threshold. When the outputs of all the phototransistors return to "0", the next state change from "1" to "0" is output by the sense logic 652. In one embodiment, the sense logic 652 may comprise a field programmable gate array.

[0146] In other embodiments, the sensing logic 652 may be executed by a microprocessor that senses or samples the output of each detector during a corresponding clock cycle and initializes operation in response to any of the detectors transitioning from a high state to a low state or vice versa. Then, on the next cycle, when all the detectors once again output a high state, the microprocessor executes the sensing logic 652 . In some embodiments, a vehicle, such as vehicle 600 of FIG. 11, may include a microprocessor that not only monitors sensing placement mechanisms such as 602 and 604, but may also control the movement of conveyor 406 and the vehicle itself.

[0147] Embodiments consistent with this disclosure may employ a sensing and positioning mechanism, such as sensing and positioning mechanism 500 of FIGS. 8-10, in conjunction with a system for conveying an object along a conveyance path. Such a system may define one or more object support surfaces S and further include one or more object transfer mechanisms, each capable of moving one or more objects supported by the object support surface S in at least one object transfer direction. In some embodiments, the support surface(s) may be defined by the surfaces of one or more belt conveyors, one or more roller conveyors, one or more inclined tables, or one or more stationary tables. Where tilted or stationary tables are used, their object support surfaces S may have holes fluidly connected to a source of pressurized air to reduce friction during object transfer operations.

[0148] Moving an object onto or off of one or more object supporting surfaces S of a system constructed in this embodiment may be accomplished in a number of ways. By way of example, a push bar or other structure may provide a positive force to move an object onto and / or across and / or off of the object support surface S. Alternatively, the object support surface S may be reoriented (tilted) by the object transfer mechanism so that the object moves by gravity onto another object support surface S or into a container or carton at the destination. According to a further embodiment, the object transport mechanism may include a conveyor having, for example, a belt defining the object support surface S. In such an embodiment, the belt may be driven in a first direction to transport the objects to a first discharge end of the object transfer mechanism so that the objects are sorted, for example, into a first waiting container. Similarly, the same belt may be driven in a second direction to transport objects to a second discharge end of the object transfer mechanism so that the objects are sorted, for example, into a second waiting container.

[0149] In some embodiments, one or more object support surfaces and optionally one or more object transport mechanisms of the material handling system may be moved to an object destination by a transport vehicle 600. In one embodiment, a conveyor-equipped transport vehicle 600 such as the transport vehicle 600 of FIG. 11 may be used as part of a material handling system, such as a device for sorting objects into groups of “n” items. In some embodiments, "n" is equal to or greater than one. And each group includes one or more objects that are placed into a single shipping carton for shipment to a single customer as part of an order fulfillment process.

[0150] In some embodiments, an object transfer cycle is initiated when the leading end of an object enters a detection surface formed by a sensing placement mechanism such as sensing placement mechanism 500 of Figures 8-10, and the object transfer cycle is completed when the trailing end of the object exits the detection surface / light curtain. Completion of each cycle consists of verifying that an object has been transferred from the object supporting surface S of the transport vehicle 600 and into one of the plurality of receptacles 119. The ability to accurately detect the completion of each cycle for objects of various shapes, sizes and optical characteristics allows each vehicle transport 600 to return to the filling station and / or object transfer station 310 without delay. The delay may occur in other cases due to a missed detection. Similarly, the risk of the transport vehicle 600 departing from a sorting destination proximate one of the multiple output bins 190 before the transfer is completed and / or the risk of the transport vehicle 600 departing from the loading station 310 before the transfer is completed is also substantially reduced regardless of the shape and opacity of the object. <Operation>

[0151] The material handling system 10 operates as follows. The items are processed at induction station 50 and characteristics of the items are identified which indicate the location where the parts should be sorted. As previously discussed, the items may be processed and whether or not the items are eligible to be transported to one of the haul vehicles 200 may be determined based on the physical characteristics of the items. A central controller maintains data relating various data and identifies the destination output bin or location for each item processed.

[0152] As previously mentioned, induction station 50 may process items automatically or manually. In the manual case, an operator manually enters information about the parts and then places the parts on the conveyor. The system electronically tags the parts with sorting information and the conveyor carries the parts towards a loading dock 310 . Alternatively, if induction station 50 is an automated system, the parts may be automatically scanned and associated sorting information identified. For example, induction station 50 may use a scanner, such as a bar code scanner, to read the bar code on the part. Alternatively, guidance station 50 may include an imaging device, such as a high speed line scan camera in conjunction with an OCR engine, to read the information on the parts.

[0153] To prepare to receive an item, the transport vehicle 200 travels along the track 110 toward a loading station 310 within a loading column 300 . As the haul vehicle 200 moves into position at the loading dock 310 , the home sensor detects the presence of the haul vehicle 200 and sends a signal to the central processor indicating that the haul vehicle 200 is located at the loading dock 310 .

[0154] Once the haul vehicle 200 is located at the loading station 310 , the guide station 50 transfers the items onto the haul vehicle 200 . As the items are transported onto the transport vehicle 200 , a loading mechanism 210 on the transport vehicle 200 loads the items onto the transport vehicle 200 . In particular, the induction station 50 carries the items and directs the items into contact with the conveyor belt 212 on the transport vehicle 200 . The conveyor belt 212 rotates toward the rear of the transport vehicle 200 , thus moving the items toward the rear of the transport vehicle 200 .

[0155] The operation of the conveyor belt 212 is controlled by loading sensors 230a, 230b. As an item is loaded onto the haul vehicle 200, a front loading sensor 260 detects the leading edge of the item. Once the front loading sensor 260 detects the rear end of the item, the controller on the haul vehicle 200 determines that the item is loaded onto the haul vehicle 200 and stops the conveyor motor. Additionally, the on-board controller may control operation of the conveyor in response to signals received from the rear loading sensor 262 . In particular, when the rear loading sensor 262 detects the leading edge of the item, the leading edge of the item is proximate to the rear end of the haul vehicle 200 . To ensure that no items extend beyond the rear end of the transport vehicle 200, the controller may stop the conveyor once the rear loading sensor 262 detects the leading edge of the item. However, if the rear loading sensor 262 detects the leading end of the item before the front sensor detects the trailing end of the item, the controller may determine that there is a problem with the item (i.e., an item that is too long or two overlapping items have been delivered to the transport vehicle 200). In such a case, the material handling system may tag the part as waste and eject the item into a waste bin 325 located behind the loading dock 310 . In this manner, if there is an error loading an item onto the haul vehicle 200 , the item may simply be ejected into the waste receptacle 325 and the next item may be loaded onto the haul vehicle 200 .

[0156] After an item is loaded onto the transport vehicle 200 , the transport vehicle 200 moves away from the loading station 310 . In particular, once the on-board controller determines that the items are properly loaded onto the haul vehicle 200, the on-board controller sends a signal to start the drive motor. The drive motor turns the axle, which in turn rotates the gears 222 on the wheels 220 . Gear 222 meshes with drive surface 156 of vertical rail 305 of the loading column to drive transport vehicle 200 upwardly. In particular, gears 222 and drive faces 156 mesh and act like a rack and pinion mechanism to convert the rotational motion of wheels 220 into linear motion along tracks 110 .

[0157] As the haul vehicle 200 travels up the loading column from the loading station 310, the destination of the haul vehicle 200 does not need to be determined until after the haul vehicle 200 reaches the first gate along the upper rail 135. For example, if an automated system is used at induction station 50 to scan and determine the characteristics used to sort items, some processing time may be required to determine which characteristics are relevant and / or receive destination information by communicating that information to a central controller. The time it takes to load the items onto the transport vehicle 200 and then to roll the transport vehicle 200 up to the loading column is typically sufficient to determine the relevant characteristics for each item. However, if the characteristics have not been determined by the time the transport vehicle 200 reaches the upper rail 135, the material handling system may declare the item not eligible for sorting, and the transport vehicle 200 may be directed to a redirection station 430 and discharge the item onto the discharge assembly 410. From the redirection station 430, the haul vehicle 200 travels down the second column to the lower rail and then back to the loading column.

[0158] Once an item is qualified for sortation, the central controller determines the appropriate output bin 190 for the item. Based on the location of the output bins 190 for each item, the route of the haul vehicle 200 is determined. In particular, the central controller 350 determines the routes for the transport vehicles 200 and communicates with the transport vehicles 200 information regarding the output bins to which items are to be transported. The central controller 350 then controls gates along the track 110 to direct the haul vehicles 200 to the appropriate columns. Once the transport vehicle 200 reaches the appropriate column, the transport vehicle 200 moves down the column to the appropriate output bin 190 . The haul vehicle 200 stops at the appropriate output bin 190 and the on-board controller sends an appropriate signal to the conveyor motor 255 to drive the conveyor belt 212 . The conveyor belt 212 carries the items forward and discharges them into the output bin 190 . In particular, the top surface of the transport vehicle 200 is positioned to conform to the gap between the appropriate output bin 190 and the bottom edge of the output bin 190 immediately above it.

[0159] In this case, the orientation of the transport vehicle 200 does not substantially change as the transport vehicle 200 goes from moving horizontally (along the upper or lower rail) to moving vertically (down one of the columns). In particular, when the transport vehicle 200 moves horizontally, the two geared front wheels 220 cooperate with the upper rail 135 or lower horizontal rail 140 of the front track 115, and the two geared rear wheels 220 cooperate with the corresponding upper rail 135 or lower horizontal rail 140 of the rear track 120. As the transport vehicle 200 passes through the gate and into the column, the two geared front wheels 220 engage with a set of vertical sections 130 of the front track 115 and the two geared rear wheels 220 engage with corresponding vertical sections of the rear track 120.

[0160] When the transport vehicle 200 moves from a horizontal rail to a vertical column, or from a vertical column to a horizontal rail, the track 110 ensures that all four geared wheels are at the same height. In this manner, as the haul vehicle 200 moves along the track 110, the haul vehicle 200 does not warp or tilt as it changes between horizontal and vertical movement. <Traffic Control>

[0161] Since the system includes many haul vehicles 200, the material handling system controls the operation of the different haul vehicles 200 and ensures that the haul vehicles 200 do not collide with each other. In the discussion below, this is referred to as traffic control. An exemplary methodology for controlling traffic flow is described in US Pat. No. 7,861,844.

[0162] In this case, some of the columns may have two vertical rails 130 that are independent of the adjacent columns. For example, loading column 300 has two independent rails that are not shared with adjacent columns. Thus, a haul vehicle 200 can move up the loading column regardless of the position of the haul vehicle 200 in the columns adjacent to the loading column. Additionally, it may be desirable for adjacent columns of the loading column to be configured with two independent vertical rails 130, as shown in FIG. In this manner, the transport vehicle 200 can move the loading column up and the adjacent column down. You can move more freely in the opposite direction.

[0163] In the preceding discussion, sortation of items has been described with reference to a row of output bins 190 located at the front of sortation station 100. However, as shown in FIGS. 3-4, the number of output bins 190 in the material handling system is doubled by providing a rear row of bins behind the sortation station 100. In this manner, the transport vehicle 200 can transport items to an output bin 190 at the front of the sortation station 100 by moving to the output bin 190, rotating the conveyor on the transport vehicle 200 forward, and discharging the items into the front output bin 190. Alternatively, the transport vehicle 200 can transport items to an output bin 190 at the rear of the sortation center 100 by moving to the output bin 190 and rotating the conveyor on the transport vehicle 200 backwards to eject the items into the rear output bin 190. Additionally, sorting station 100 is modular and can be easily expanded by simply attaching additional sections to the left end of sorting station 100 as needed. <Vehicle control based on item features> 1. Vehicle movement profile

[0164] As previously mentioned, one or more characteristics of the items being transported by the haul vehicle 200 may be detected or determined for each item during processing. The detected information may be used to control further processing of the item. In particular, the control of the haul vehicle 200 between the loading dock 310 and the output bin 190 may vary depending on the detected information. Additionally, the movement of the haul vehicle 200 along the track may vary depending on the detected characteristics.

[0165] The parameters of the movement of the haul vehicle 200 may be varied based on the detected information. The list of movement variables includes, but is not limited to, the acceleration profile (i.e., how quickly the haul vehicle 200 accelerates), the deceleration profile (i.e., how quickly the haul vehicle 200 decelerates), and the cornering speed (i.e., how quickly the haul vehicle 200 moves around a corner). Another method of vehicle control in response to detected information is the method of ejecting items from the haul vehicle 200 . In particular, the speed of the belt of the transport vehicle 200 may be increased or decreased, and the speed at which items are discharged may be varied.

[0166] By way of example, the material handling system may have a reference control profile that is used to control the movement of the haul vehicle 200 along the track 110 . Under the reference profile, the haul vehicle 200 moves along the trajectory 110 with a first peak velocity, a first acceleration, and a first deceleration. Furthermore, under the reference moving profile, the haulage vehicle 200 has a first peak speed when the haulage vehicle 200 moves around a curved road from horizontal to vertical or from vertical to horizontal. The reference profile may be applied to a variety of items having a set of features that fall within the reference feature profile, such as flat items having a reasonable weight (eg, books, boxes, etc. weighing a few ounces or more). However, if the material handling system detects a feature that does not fall within the reference feature profile, the material handling system may control the movement of the haul vehicle 200 in a variable manner. In particular, the material handling system may control movements according to a second movement profile. For example, if the material handling system detects that the element is cylindrical, the material handling system may control the haul vehicle 200 according to a movement profile that differs from the reference profile. The haul vehicle 200 may accelerate more slowly than the baseline profile to reduce the chance of the items rolling on the haul vehicle 200 . Similarly, the haul vehicle 200 may slow down more slowly and travel at a lower speed around curved roads to reduce the chance of items rolling on the haul vehicle 200 .

[0167] As described above, control of the haul vehicle 200 may be controlled according to a movement profile, which may vary based on one or more characteristics determined for each item being hauled by the haul vehicle 200. The material handling system may store many movement profiles, each of which controls the movement of the haul vehicle 200 along the track 110 according to different parameters. Each movement profile may be correlated with one or more characteristics of a particular item. In this manner, various items having one or more shared characteristics may share the same movement profile. For example, non-curved frangible items may all share the same movement profile, and curved or cylindrical frangible items may all share the same movement profile.

[0168] In this manner, the material handling system may dynamically control the movement of each haul vehicle 200 based on one or more characteristics determined for each item being hauled on each haul vehicle 200 . The characteristics can be determined by directly detecting the characteristics (eg, scanning, weighing, dimensional measurement, etc.). Alternatively, one or more characteristics may be stored in a central database and determined by identifying the item, such as a product code. In addition to, or instead of, storing information about the characteristics of each item, the database may simply contain data identifying the movement profile used for each item. In such cases, the material handling system or an operator scans the item to detect product identification features (such as a bar code or other identifying information). A vehicle movement profile is identified in a central base for each item, and after the item is identified, the material handling system retrieves the vehicle movement profile data from the central database. 2. Vehicle destination control

[0169] As described above, the material handling system may control the movement of the haul vehicle 200 based on detected or determined information about items being carried on the haul vehicle 200 . Additionally, the destination of the haul vehicle 200 may vary based on one or more characteristics of the items. For example, information regarding the physical characteristics of various items may be stored in a central database. By scanning an item for each product identification code, the material handling system can retrieve data regarding the item's physical characteristics from a central database. This data is the expected physical characteristics of each item. For example, based on the data stored for each product identification code, an item may be expected to be 5 inches long, 3 inches wide, and weigh 8 ounces. If the scanning station 80 measures the item as being 8 inches long and / or weighing 16 ounces, the material handling system may modify the item's destination. In particular, based on the scanned product code, the material handling system may instruct the transport vehicle 200 to deliver the item to bin "X." However, when the material handling system detects physical characteristics that do not match the expected characteristics, the material handling system may change the destination container. In the example above, if the item is scanned and weighs 16 ounces, the material handling system may transport the item to bin "Y." Container "Y" may be a larger alternate container, or may be an unsorted or waste container that receives items that differ from the expected physical characteristics. 3. Vehicle destination control

[0170] The material handling system may also control how items are discharged or transported in the output bin 190 based on determined or detected physical characteristics of the items. If the item is fragile, the material handling system may control the transport vehicle 200 to rotate the conveyor belt more slowly and discharge the item into the output bin 190 more slowly. Additionally or alternatively, the position of the haul vehicle 200 relative to the output bin 190 may vary based on the detected or determined characteristics. For example, if an item is fragile, the material handling system may stop the transport vehicle 200 lower relative to the output bin 190, positioning the item closer to the bottom of the output bin 190 and therefore reducing the vertical drop of the item as it is discharged into the output bin 190.

[0171] 13 and 14, when multiple items are being delivered to the same output bin 190, the system may control the position of the transport vehicle 200 relative to the output bin 190 to reduce the distance the items must fall as they are discharged and to reduce the chance of items causing jams as they pile up on top of each other. Position control of the transport vehicle 200 during a transport may vary depending on detected or determined characteristics of one or more items being sorted into the transport bin.

[0172] As shown in Figures 13 and 14, when multiple items are transported to a single output bin 190, the material handling system may divide the single output bin 190 into three virtual sorting destinations. The material handling system then sorts the three items into three virtual sort locations. For example, as shown in FIG. 13, when viewed from the front, output bin 190 may be divided into three virtual sorting positions (position 1, position 2 and position 3). In FIG. 13, a single output bin 190 is divided into three virtual locations having the same height. However, the magnitude of each virtual location may vary based on one or more characteristics determined or detected for each item. Additionally, the virtual locations are prioritized based on judged or detected characteristics of the items. For example, if multiple items are to be transported into an output bin 190, where one item is fragile and one item is heavy and / or dense, the material handling system may prioritize the virtual locations by prioritizing the heavy items to be transported into the output bin 190 first and the fragile items to be transported into the output bin 190 second, minimizing the possibility of damage. To prioritize the order of transport, the material handling system may control the flow of transport vehicles 200 and cause transport vehicles 200 transporting fragile items to wait or delay.

[0173] Similarly, rather than virtually splitting a single output bin 190 into multiple sorting locations, the system may virtually merge multiple output bins 190 into a single virtual output bin 190 in a certain order based on determined or detected characteristics of the multiple items. For example, if multiple items are delivered to a single output bin 190, but the order in which the items are placed in the output bin 190 is determined by physical characteristics of the different items, the material handling system may deliver items to more than one output bin 190 (preferably adjacent bins). The items are then sorted into different output bins 190. Returning again to the example of a fragile first item and a heavy second item, when the material handling system detects or determines these characteristics, if the fragile item is delivered to the output bin 190 before the transport vehicle 200 with the second item reaches the output bin 190, the material handling system may dynamically reallocate the items so that they are delivered to two separate output bins 190 rather than just one output bin 190. After the two items have been conveyed to the two separate output bins 190, the material handling system provides a signal to an operator. The signal indicates that the items in the two separate output bins 190 should be collected together and treated as one order rather than two separate orders.

[0174] When one output bin 190 is split into multiple sorting locations as shown in FIG. 13, the system may control the operation of the transport vehicle 200 to vary the position of the transport vehicle 200 relative to the output bin 190. For example, referring to FIG. 14 , when a transport vehicle 200 carrying a first item to the output bin 190 reaches the output bin 190, the material handling system controls the transport vehicle 200 to move forward to follow the lowest position of the output bin 190 (e.g., position 1 in FIG. 14 ) and discharge the item into the output bin 190 so that the first item is located at the bottom of the output bin 190. The transport vehicle 200 carrying a second item to be delivered to the output bin 190 is then moved forward to be positioned in line with the second lowest position (i.e., position 2) of the output bin 190, and the transport vehicle 200 discharges the item into the output bin 190 so as to position the second item above the first item. Finally, the transport vehicle 200 carrying the third item to be transported to the output bin 190 is moved forward to be positioned in line with the highest position of the output bin 190 (i.e., position 3), and the transport vehicle 200 discharges the item into the output bin 190 so that the third item is positioned above the first and second items.

[0175] As shown in FIG. 14, the rear wall of the output bin 190 may be open to allow the transport vehicle 200 to pass behind the output bin 190 and discharge items at various heights along the height of the output bin 190. However, it should be appreciated that rather than having an open rear wall, the rear wall may be removable or collapsible and the transport vehicle 200 may be stopped at various locations along the height of the output bin 190 and items may be discharged into the output bin 190.

[0176] As mentioned above, various parameters regarding how items are conveyed to output bin 190 may be varied based on one or more physical characteristics determined or detected for each item. Additionally, the system may include additional elements that are optionally used during transportation based on characteristics determined or detected for each item. For example, the transport vehicle 200 may include separate extensible belts. Alternatively, the conveyor belt 212 may be mounted on a carriage positionable against the wheels of the transport vehicle 200 such that the conveyor belt 212 is extendable or telescopic outwardly toward the output bin 190 . In particular, the conveyor belt 212 may be extendable into the output bin 190 such that the conveyor belt 212 can rotate forward to eject the conveyor belt 212 into the output bin 190 . By extending the conveyor belt 212 into the output bin 190, the height from which items fall as they are transported into the output bin 190 is reduced. Additionally, the conveyor belt 212 may be controlled not to begin moving until the conveyor belt 212 extends completely into the output bin 190 . The conveyor belt 212 is rotated and ejects the items. While the conveyor belt 212 is rotating, the conveyor belt 212 is retracted towards the transport vehicle 200 . The action of discharging the items while the conveyor belt 212 is retracting simultaneously causes the items to drop more gently into the output bin 190 .

[0177] Alternatively, rather than using an extensible conveyor belt 212, the material handling system may selectively use a chute at the output bin 190 in response to detecting or determining a physical characteristic of the item. In particular, in response to detecting or determining an item having a selected characteristic, the system may direct the haul vehicle 200 forward to a particular output bin. A chute may be mounted on the rack and the transport vehicle 200 drives the chute such that items are discharged down the chute and into an output bin.

[0178] It will be appreciated by those skilled in the art that variations and modifications may be made to the above-described embodiments without departing from the broad inventive concept of the present invention. For example, in the preceding discussion, the material handling system is described as a series of transport vehicles 200 guided by tracks. However, it should be understood that a material handling system need not include a track. For example, the haul vehicle 200 may move along a ground surface rather than along a track. The haul vehicle 200 may be guided along the ground by one or more sensors and / or a controller. Optionally, haul vehicles 200 may be guided in response to signals from other haul vehicles 200 and / or from a central controller, such as a computer. A central controller, such as a computer, monitors each of the haul vehicles 200, controls the movement of the haul vehicles 200, and prevents the haul vehicles 200 from colliding with each other. Additionally, the central controller may provide signals to direct each haul vehicle 200 along a route to a storage or transfer location.

[0179] In addition to systems in which the haul vehicle 200 moves along the ground without tracks, the material handling system may incorporate a guidance assembly including one or more rails or other physical guides. The physical guidance involves contacting features on the transport vehicle 200 to direct the transport vehicle 200 along the path. For example, the transport vehicle 200 may include one or more contact elements, such as wheels, rollers, guide tabs, pins, or other elements that engage a guide assembly. The guide assembly may be a linear element, such as a straight rail, or it may be a curved element. The guide assembly may be curved in a horizontal plane to accommodate the rail in the plane. The guide members may also be vertically curved so that the rails lie in a single plane. The guide assembly may include multiple guide members or rails spaced vertically apart from one another to allow the transport vehicle 200 to move horizontally at multiple vertical positions. The guide members may also include elevators that move the transport vehicle 200 between a number of vertically spaced rails.

[0180] As can be appreciated from the above, the material handling system may be incorporated into a variety of material handling systems that guide the transport vehicle 200 along an open area using physical guidance mechanisms or by directing a path that guides the transport vehicle 200 to a storage or transfer location. As discussed above, the movement of each haul vehicle 200 may be controlled in response to determining one or more physical characteristics of the items that the respective haul vehicle 200 carries.

[0181] The material handling systems and methods described herein may, in different embodiments, be implemented in software, hardware, or a combination thereof. Additionally, the order of the methods may be changed, and various elements may be added, reordered, combined, omitted, or otherwise modified. All examples described herein are given in a non-limiting manner. Various modifications and changes may be made as will be apparent to those skilled in the art having the benefit of this disclosure. Implementations according to embodiments have been described in the context of specific embodiments. These embodiments are intended to be illustrative and not limiting. Many variations, modifications, additions and improvements are possible. Thus, multiple examples may apply to a part that is described as a single example herein. Boundaries between various components, operations and data stores are somewhat arbitrary, and particular operations are illustrated within the context of specific illustrative configurations. Other functional arrangements are envisioned and may fall within the scope of the claims set forth below. Finally, structures and functions shown as separate within the exemplary configurations may be implemented as combined structures and elements. These and other variations, modifications, additions and improvements may fall within the scope of the embodiments as defined in the claims that follow.

[0182] It is to be understood therefore that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications within the scope and spirit of the invention as set forth in the claims. [Explanation of symbols]

[0183] 10. Material handling equipment (material handling system) 50...Induction station 55···Input conveyor 60. Shoot 70···Transport conveyor 80. Scanning Station 85 Optical imaging element (camera) 88...Optical imaging element 100 Sorting area 110...orbital 115...Anterior orbit 120...posterior orbit 130 Vertical track section 135···Horizontal upper rail (upper rail) 140···Lower return section (lower rail, lower horizontal rail) 156 Drive surface 190···Output container 200···Transport vehicle 210 Loading / unloading mechanism 212···Conveyor belt 215···Axle 220...Front wheel 220A...Front wheel 220B...Back wheel 222···Gear 230 Sensor 231...tip wall 232...Rear end wall 234...front end 236...Rear end 230... Detector 230A···Advanced sensor 230B Rear sensor 300 Loading column 310 Loading area 325···Waste Area (Waste Container) 410 Redirection assembly (discharge assembly) 430...Re-induction station 440···Roller bed 450...End guide member 455 Access opening 460...end wall 500...Sensing arrangement mechanism 506... Detector 500···End Detection Assembly 502... "Curtain" of Light 502: Object is on the detection surface 504 Emitter (light source, optical energy source) 506 Emitter 508... Linear row 510 First fixed support 512 Integrated emitter / detector assembly 516...Reflector 518...Second fixed support 520...Support shaft 522··Lens 526a Transverse hole 530...reflective surface 518 - Second rigid member 600···Transport vehicle 602: First detection assembly (end detection assembly) 604 Front detection assembly (end sensing assembly) 606···Conveyor belt 610 Electric motor 611···Conveyor shaft 612...Belt 650.... Circuit capable of transmitting a signal indicative of a change in a sensed state 652 Sensing logic S... Surface that supports the item A: Transport route direction B: Second transport direction (transport path direction)

Claims

1. 1. An apparatus for sorting a plurality of items, comprising: a plurality of sorting destinations positioned vertically apart from one another; a plurality of transport vehicles movable in the vertical direction for transporting the items to the sorting destinations; a controller providing signals to control operation of the transport vehicle to transport the items to the destination; a first detector for detecting a first feature of each of the items; a second detector for detecting a second characteristic of each of the items; 1. An apparatus for sorting a plurality of items, wherein the controller is configured to determine a destination to which a first item is to be transported based on the first characteristic detected for the first item, and is configured to control operation of a first transport vehicle to vary a vertical position of the first transport vehicle relative to the determined destination depending on a second characteristic of the first item.

2. a second detector for detecting the second characteristic of each of the items; The apparatus of claim 1 , wherein the second characteristic is a height, a length, a width or a weight of the item.

3. 3. The apparatus of claim 2, further comprising a vertical guide member for vertically guiding said transport vehicle for transporting said items to said destinations.

4. 4. The apparatus of claim 3, wherein the controller is configured to control operation of the first transport vehicle in response to the second characteristic of the first item, such that a vertical position of the first transport vehicle relative to the determined sorting destination varies depending on the second characteristic.

5. a loading mechanism for loading items onto the transport vehicle; 5. The apparatus of claim 2, wherein the second detector is disposed along the loading mechanism.

6. the transport vehicle is independently operable; The apparatus of claim 1 , wherein the haul vehicle includes an on-board power source that provides power to the haul vehicle.

7. the sorting destination includes an output bin; 7. The apparatus of claim 6, wherein the output bin has a rear end through which the items pass as they are discharged into the output bin.

8. 1. A method for sorting a plurality of items into a plurality of vertically spaced apart sort locations, comprising: loading the items onto a transport vehicle; detecting a first characteristic of the item; detecting a second characteristic of the item; determining an output bin to which the item is to be delivered based on the first characteristic; vertically moving the transport vehicle to the determined output bin; controlling a position of the delivery vehicle relative to the output bin based on the detected second characteristic; Discharging the items from the transport vehicle into the output bin; moving the transport vehicle from the output bin so that a second item can be loaded onto the transport vehicle; A method comprising:

9. said step of vertically moving said transport vehicle to said determined output bin comprises the step of moving said transport vehicle along a vertical guide member; the vertical guide member includes a surface; the transport vehicle includes a rotatable element; The method of claim 8 , wherein the step of moving a transport vehicle along the vertical guide member comprises moving the rotatable element along the surface of the vertical guide member.

10. 10. The method of claim 8 or claim 9, wherein the step of controlling the position of the transport vehicle comprises controlling a vertical position of the transport vehicle relative to the destination in response to the detected second characteristic.

11. the transport vehicle includes a transfer mechanism; 11. The method of any one of claims 8 to 10, wherein the step of loading the items comprises the step of operating the transfer mechanism.

12. conveying said items to a loading location; the step of loading the items onto the transport vehicle includes loading the items at the loading location; 12. The method of claim 8, wherein the step of detecting the first characteristic occurs during the step of conveying the item towards the loading location.

13. The method of claim 12 , wherein the step of detecting the second characteristic occurs during the step of conveying the item toward the loading location.

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