GB2630597A

GB2630597A - Sorter carrier

Info

Publication number: GB2630597A
Application number: GB2308085.6A
Authority: GB
Inventors: John Hyslop David
Original assignee: Hysort Ltd
Current assignee: Hysort Ltd
Priority date: 2023-05-30
Filing date: 2023-05-30
Publication date: 2024-12-04
Also published as: GB202308085D0; WO2024246491A1

Abstract

A sorting apparatus has a track arrangement with at least one sort location and having a plurality of levels. At least a first sorter carrier 101a and a second sorter carrier 101b carry items 102 to be sorted with each sorter carrier including a drive arrangement. A lift has at least one platform large enough to take the carriers between levels simultaneously and transported together or may be transported on the lift separately. A control system may group carriers together where the carriers are destined for the same level or travel in the same direction for the lift or where an oversize package requires the width of two carriers to move it.

Description

A SORTING SYSTEM

This specification relates to package sorting. In particular, although not exclusively, this specification relates to a package sorting system.

A sorter using independently driven item carriers, with either a cross belt or other discharge system, has the ability to move past the sort destination with varying speed. From the carrier's maximum speed to zero at the time of item discharge. Individual carriers can be moved vertically within the machine by a lift allowing multiple levels of sort destinations to be accessed which reduces the floorspace required for the sort destinations and sorter. The carriers travel along different levels between multiple lifts forming a return path for the carrier to come back to collect additional items from one or more item induct points.

The efficiency of such a sorting system can be described by a measure of the the throughput capacity per hour. The throughput can be increased by increasing various parameters such as the acceleration, deceleration and top speed of the system components such as the carriers or lifts by using more powerful or faster motors. However bigger motors are more expensive, heavier and so may require more power to achieve incremental increases and practical limits exist which limit further increases in sorter throughput, e.g., if the lift motor is accelerated downwards at an acceleration greater than the acceleration due to gravity the item may leave the carrier and go into freefall before crash landing again as the carrier or lift decelerates again. Similarly, if the carrier is accelerated too quickly the item is likely to slide around on the carrier and may fall of into the machine.

This specification uses innovative methods of operation of the sorting machine components to achieve increased throughput rather than merely making the motors run faster.

Independently driven carriers are a significant part of the cost of the total sorter solution as they each have a controller, sensors, drive motor and power pickup onboard (and possibly energy storage e.g., a battery or a capacitor).

Carriers slowing down or stopping, to sort an item, prevent other carriers, on the same level, from overtaking. This reduces the overall throughput rate of the sorter. Adding more carriers increases the capacity of the sorting machine up to the point other bottlenecks are reached i.e., the capacity of lifts or item induct stations. Additional carriers, however, increase the cost to the sorter. Finding a way to maximise the throughput of the carriers allows the best combination of capital cost and sorter capacity per hour. Similarly finding a way to maximise the throughput of the lift mechanisms improves the overall performance and return on investment of the sorting system.

Therefore, a mechanism for maximising the throughput of an item sorting machine has been developed. This may employ a set number of independent carriers, and may vary and optimise, for each item to be sorted, the speed of the item carrier and discharge mechanism before and during the discharge of the item. A previous innovation uses the item attributes, dimensions and position on the carrier to allow the control system to optimise the carrier drive motors.

In addition, the systems and methods may allow the minimisation of the number of carriers needed to reach the throughput of an item sorting machine, by varying and optimising, for each item to be sorted, the speed of the item carrier and discharge mechanism before and during the discharge of the item. The previous innovation uses the item attributes, dimensions and position on the carrier to allow the control system to optimise the carrier drive motors and improve the overall throughput of the sorting system where the speed and number of carriers create a sorter capacity bottleneck.

In the current innovation another component of the sorting system is considered, the Lift or Lifts, and an apparatus and method is used to increase the throughput of carriers over the Lifts to increase the throughput of the overall sorting system.

Background

Conventional parcel or item sorting machines operate at a constant speed with the items to be sorted transported to the sort destinations on a series of linked carriers or conveyors. Destinations are usually on one level and the items are sorted by applying a force to the item to move it off one side (or the other) of the sorter and into a chute or other destination.

The sort destination could be a gravity chute, container or glace. The sorter carriers or conveyor move past the fixed destination at a constant speed. When a carrier needs to eject or sort out an item the carrier (or conveyor divert mechanism) activates at a fixed point relative to the destination, and the item is moved into the destination (chute) opening. The opening must therefore be wider than the largest width of item to be sorted to allow the carrier to continue its forward motion with respect to the destination opening whilst being able to sort out the item successfully without jamming. Frequently a funnel is used to guide the item into a narrower chute or destination container (roll cage, stillage, bag or tote etc.).

Items for a particular sorting destination (e.g., a parcel depot, delivery van or shops) enter into the destination in the order that they are inducted onto the sorting machine (on occasions items may recirculate past their destination and be overtaken by other items).

In order to maximise the return on the capital investment of this type of machine it is desirable to achieve a high throughput of the system. However, such prior systems have limitations regarding desired throughput optimisation.

An aspect of the invention provides a sorting apparatus as defined in claim 1 and dependent claims below.

Preferably, the information about the or each item to be sorted includes at least the desired order or grouping which the item will be collated into at one or more sorter destinations.

Conveniently, the information about the or each item to be sorted is provided by way of a data file or other information sharing interface between a host system and the sorter controller or is contained in a machine-readable format e.g., a barcode on the item which can be detected by the sorter control systems.

Advantageously, the sorter arrangement includes a camera, vision system, and/or photocell to measure the size and position of the item once inducted onto a sorter carrier, and/or a barcode reader to identify the item to be sorted.

Preferably, the or each sorter carrier includes a speed control.

Conveniently, the information about the or each item to be sorted is used to determine and control the speed of the carrier and the point of discharge of the or each item to be sorted. This seeks to maximize the throughput of the carrier and sorting system.

Advantageously, the control arrangement is configured to adjust the position of the item on the carrier by way of the discharge arrangement such that it is moved towards the side of the or each sorter carrier adjacent to the or each sort location prior to arrival at the or each sort location. This seeks to minimise the distance of travel required to discharge the item into the destination and allowing a higher carrier speed.

Preferably, the information about the or each item to be sorted includes the coefficient of friction of and/or mass of the or each item to be sorted.

Advantageously, the apparatus includes an item scanning arrangement configured to read information about the or each item to be sorted Preferably, the sorting apparatus includes at least a first sorter carrier and a second sorter carrier.

Conveniently the sorter framework includes at least one lift, and preferably two lifts or more to move the carriers between sorting destinations on different levels. Advantageously, the sorting carriers are captive within the framework, and a sorting system as outlined in the claims below as supported by the description.

Brief Description of the Drawings

An exemplary embodiment of the present invention is illustrated by way of example in the accompanying drawings in which like reference numbers indicate the same or similar elements and in which:-

Figure 1 shows a prior art sorting apparatus;

Figure 2a shows an exemplary sorter carrier; Figure 2b shows an alternative, exemplary sorter carrier; Figure 3 shows an exemplary sorting machine using a number of carriers and lifts to allow the carriers to change levels and sorting destinations either side of the sorter on 5 levels.

Figure 4 shows a top view of a carrier and item to be sorted as it passes by a group of sort destinations; Figure 5 shows a representation of the locus of travel of an item successfully sorted to a destination by a carrier moving past a row of sort destinations; Figure 6 shows a representation of the locus of travel of an item when positioned in two places on a carrier; Figure 7 shows a diagrammatic representation of an exemplary sorting machine using a number of carriers within a framework; Figure 8 shows sorting carriers in accordance with aspects of the present invention as a front perspective within a frame with a lift each carrier carries a separate item or parcel to be sorted these items are not shown on the drawing; Figure 9 shows the carriers and frame depicted in figure 8 with a single item across two carriers in a lift between levels; Figure 10 shows an expanded view of a sorting system in accordance with aspects of the present invention and with frames and sorters as depicted in figure 8 and figure 9; Figure 11 shows a table of order combinations and item destinations in accordance with aspects of the present invention; Figure 12 shows a table of other orders combinations and destinations in accordance with aspects of the present invention; Figure 13 schematically shows a long parcel across two sorting carriers or shuttles and a destination chute containing a similarly long parcel; and, Figure 14 schematically shows a long parcel on two shuttles or sorting carriers and as turned by such carriers to a sorting location or chute.

Referring firstly to Figure 1, there is shown a conventional prior art sorter which is continuously moving in direction 11 perpendicularly to destination chutes 12.

Particularly, Figure 1 shows a conventional sorter with destination chute width greater than the width of the largest item to be sorted to allow for the speed of travel of the carrier as it sorts and moves past the destination simultaneously.

Items are transported on the interconnected carriers 13 and discharged in the direction of the discharge mechanism, in this example the discharge mechanism is a cross belt which moves perpendicularly to the direction 11, into the destination chutes. Each chute has a throat wider than the maximum width of items allowed on the sorter so that the item can always be discharged fully within the time between when the trailing edge 14 of the item passes the chute opening position 15 and the time the furthest part or the leading edge of the item 16 reaches the other side of the chute opening 17.

Items 18 and 19 shown in Figure 1 are the same size but have been inducted into different positions on the carriers shown. The time taken for the carrier discharge belt to fully discharge item 18 will be less than the time taken to discharge item 19 as it is further away from the destination chute so the discharge belt has further to travel.

Sorters of the general type as shown in Figure 1 tend to fire or drive the discharge belt at fixed positions. i.e., when the trailing edge of the discharge belt has reached the start of the chute opening and the opposite corner of the discharge belt when looked at in plan view will reach the other side of the carrier before the chute opening is passed this allows items of any size which fit on the carrier to be sorted successfully irrespective of their position on the carrier after being inducted. Some sorters can allow items to straddle multiple carriers (effectively making one larger carrier) but the destination chute openings would then need to be designed to be wide enough to accommodate that mode of operation.

Turning now to Figure 2a, there is shown a sorter carrier 21 with a discharge mechanism 22. In the example shown in Figure 2a, the discharge mechanism is a conveyor belt driven across the carrier perpendicular to the direction of travel of the carrier.

The sorter carrier 21 shown in Figure 2a includes a number of features, each of which will be discussed in turn below.

The sorter carrier 21 may include an apparatus configured to drive the sorter carrier 21 in both the forward and reverse direction. Such an apparatus may be a motor or motors. Additionally, the sorter carrier 21 may include an apparatus configured to drive the discharge belt or discharge mechanism to eject the item into the sort destination. As with the drive apparatus, this may be a motor or motors or an actuator.

Further, the sorter carrier 21 may include an apparatus configured to control the movement and position, along with item loading and discharge, collision avoidance and communication with the other system controllers of the sorter carrier 21. This control apparatus may be a microprocessor controller or Programable Logic Controller (PLC), or suitable alternative.

The sorter carrier 21 may also include sensors 23 to detect the position of the sorter carrier 21 within a rail structure, along with other parameters such as overhang of product and collision avoidance. In addition to that discussed above, the sorter carrier 21 may include an optional energy store, which may include or comprise a battery or capacitor, and a power pick-up mechanism 24 to power the carrier or to recharge the energy store.

Figure 3 shows multiple carriers 31 in a sorting machine consisting of lifts 32 to move carriers between levels, item induct position 33, and five levels of sort destinations 34 in this example the destinations are totes, but they could be chutes, boxes, bags etc. It will now be described how the carriers 31 receive an item to be sorted from the induct station.

The cycle may begin with a carrier 31 at the induct position. An item is placed onto the induction belt 33. A barcode on the item may be scanned, either by the operator using a hand-held scanner or by an automatic scanner whilst the item is moving over the induction belt 33. The controller may use the data from the barcode to look up a database to determine the items intended destination. If no destination has been allocated yet the controller may choose a free destination on any level of the framework. The database may also give the item attribute data such as weight, dimensions and coefficient of friction. The sorter controller passes the items destination to the carrier controller along with any other data by infrared or radio frequency communication. Bluetooth, \MFi or other RF protocols can be used.

The carrier may then check that the item is not overhanging either end of the carrier belt and that the sensors on the carrier belt are clear. If the item is overhanging a warning appears for the operator to reposition the item. If the item is not overhanging the carrier, it is ready to move off towards the lift 31. The carrier controller detects if the lift rail is not in place or if an obstruction (most likely another carrier) is detected by its sensors. When the carrier is clear to move it moves onto the lift. The lift controller has been informed by the main sorter controller (or the lift shares the main sorter controller) what level to take the carrier and item to. Before the lift moves to the destination level. The vision system connected to the main sorter controller may capture a picture of the item on the carrier. Once the image is captured the lift may begin to move to the destination level. The vision system may work out the effective dimensions of the item and the position on the belt.

Once the lift has completed its move to the destination level the induct level is now available to receive another carrier. The main controller calculates the optimum discharge parameters of the item from the carrier and communicates these to the carrier controller. In a variant, the sorter communicates basic information and the carrier determines the optimum discharge speed and the like. Once the first carrier has moved off the lift towards its destination the vision system can capture the image of the item on a second carrier if it has arrived.

The first carrier proceeds towards the sort destination. This may be on the current level of the carrier or on the induct level. If it is the induct level then the carrier will proceed directly to the opposite end of the machine and move over the return lift before proceeding to the sort destination. If the destination is on the current level the carrier may drive at top speed towards the destination. When at an appropriate distance from the destination the carrier begins to decelerate to the discharge speed between top speed and zero m/s. The time at which this deceleration starts is the beginning of the discharge time (DT). At a point along the path the carrier fires the discharge belt, or mechanism, to offload the item into the destination.

The point the carrier starts deceleration, the deceleration rate, the point at which the discharge belt starts and stops have all been determined by the controller taking into account the item attribute data and effective dimensions and position of the item on the carrier. The item attribute data and the effective dimensions are discussed in more detail, and with reference to Figure 4, below.

Once the item has been fully discharged the carrier re-accelerates to top speed to continue its journey to the next lift, induct point or other point in the system. The time to discharge (DT') is complete once the carrier has reached its desired speed for the onward journey. It is to be understood that if the carrier is close to the return lift or induct point the carrier may not reach top speed before stopping at the next lift or induct point.

The carrier travels over the return lift back to the induct station level. The lift controllers, which may be separate controllers or the main sorter controller, ensure the proper functioning of the lift and the sequence that carriers are allowed to enter the lift by signalling their status to the carriers so the carriers may have to stop and wait before entering the lifts. The carrier controller uses its sensors to detect any obstacles along the way and avoid collisions or to detect when the lift is not available.

Returning to a discussion of the items being introduced into the system, the item barcode may contain attributes information, or an identification allowing these item attributes, including the destination where the item is to be sorted, to be looked up in a database on a host system which may, for example, be a warehouse management system. Any relevant attribute data is passed to the sorter controller and on to the carrier.

The capacity of the system will now be discussed. The time taken by the carrier to move around the loop and complete a sorting cycle depends upon its speed driving to lifts, destinations and induct points, its acceleration and deceleration profiles at the various positions, the time to discharge the item (DT') and the time to induct the item. Additionally, the carrier may have to wait for a lift or for another carrier which may be blocking its path. Although in accordance with particular aspects of the present invention as outlined below in some circumstances the discharge time (DT) for each article or parcel may be of most importance to overall sorting system performance.

The system throughput per hour therefore depends upon the average cycle time of a carrier for an item. Adding more carriers to the sorter will increase the throughput until the lifts or other positions become a bottleneck. Once the throughput of the sorter reaches the bottleneck capacity of the lifts or other positions the number of carriers can be minimised by reducing the cycle time of a carrier thereby saving capital cost.

One (another) approach configures the system so that it reduces the carrier cycle time by reducing the average DT time, which as discussed above is the time taken for the carrier to, decelerate, discharge the item and re-accelerate. The DT can be varied depending upon the item size, position on the belt and the coefficient of friction between the belt and item. It does not have to be fixed but can be optimised for each item as the carriers are independent of each other and can overtake on different levels. This is unlike in conventional sorters where the carriers are on the same level and connected together.

Accuracy of sorting is of paramount importance to sorter users. Items which miss the destination and land in the neighbouring destination bin or chute may be sent hundreds of miles across the country only to have to be returned at cost and to the detriment of customer satisfaction.

Turning now to Figure 4, it will be discussed how time and position matter. Figure 4 shows a carrier 41 moving perpendicular to an array of destinations 42 in the direction of travel 43 and carrying an item to be sorted 44. If the carrier is stationary the item will be successfully sorted into the destination by firing the discharge mechanism provided the effective width 45 is less than the width of the destination 46. The effective width should always be slightly smaller than the destination width to allow the item to fit easily into the destination. If the effective width is greater than the destination width the item is highly likely to jam or be missorted.

Figure 5 is a diagrammatic representation of the locus of travel of an item successfully sorted to a destination by a carrier moving past a row of sort destinations at a speed low enough to allow a successful sort.

Figure 6 is diagrammatic representation of the loci of travel of an item when positioned in 2 different places on a carrier showing both successful and unsuccessful sort attempts as the carrier moves past a row of sort destinations.

Figure 5 shows an item 51 which is smaller than the item 44 of Figure 4. Figure 5 also shows the locus of travel 52 of the item 51, into the destination when the carrier discharge speed is fixed and there is an acceptable positive speed of the carrier in the direction of travel 43. The larger the effective width 45 of the item 51, compared to the destination width 46, the harder it is for the item to successfully hit the target destination whilst the carrier is moving at this speed.

Figure 6 shows a further scenario, detailing the effect of an item being in a different position on the carrier for a given discharge and carrier direction 63 and speed. The position of item 61 and its locus of travel into the destination result in a successful sort however, if the item was at the position 62 it would result in a failure if the discharge belt were activated at the same time as when sorting item at position 61.

Item 62 would be correctly sorted if the discharge belt was fired earlier. If the carrier were to stop at the destination it would not matter what position the items were in so long as they were on the discharge belt and the discharge belt's width and the effective width of the item were less than the width of the destination.

Figure 7 shows a diagrammatic representation of an exemplary sorting machine using a number of carriers within a framework, the destinations are not shown to allow visibility of multiple carriers as they move through the system.

To date sorters on the market use a fixed speed of carrier moving past destinations or stop at the destination.

The attributes of width, length and coefficient of friction could be passed from a host system to the sorter controller, or the dimensions and effective dimensions can be measured using photocells and timers, a vision system or other sensors somewhere on the sorter or carrier prior to the destination being reached. The sorter controller then calculates the best carrier speed and discharge point to successfully sort the item into the destination.

Destination attributes (principally width but also coefficient of friction, orientation, existing fill etc) can also be used by the control system.

One approach is to provide the ability to vary the speed of the carrier as it passes by the destination for each sorting action. This allows the carrier to take account of the dimensions, position and other attributes of the item to determine the optimal carrier and discharge speeds thereby minimizing the number of carriers required (reducing cost) or maximising the sorter throughput. Such an approach focusses on the use of individual items per carrier but further improvements can be made as outlined below and later with regard to figures 8 to 14.

In accordance with aspects of the present invention the function of periodically grouping independently driven carriers in a sorting machine has benefits.

When two or more carriers travel together up or down a lift between levels in the framework the capacity of the lift may be increased compared to when only one carrier is taken at a time. Additionally, it becomes feasible that items or parcels of greater length can be carried by multiple carriers moving together.

The carrier or shuttle shown in Figure 2B is considerably narrower that the carrier shown in Figure 2A whilst the carrier belt size is the same. The design of carrier 2B has the belt sitting higher than any part of the frame of the carrier so an item or parcel could sit on two or more adjacent carriers' belts without touching any other part of any carrier.

Figure 8 and figure 9 illustrate a lift 100 in a sorter frame (not shown). The lift 100 moves a sorter carrier combination 101a/101b between levels in the framework. As compared with the system described above the carrier combination has two distinct carrier elements which can be independently operated and receive respective items either one item or parcel to each carrier 101a, 101b or as depicted in figure 9 a single item 102 lying across both carriers 101a, 101b. This configuration as outlined below allows some improvements in its performance. This may be contrary to the intuitive situation particularly as it will be appreciated that on occasion an item may only be present on carrier 101a or 101b so notionally reducing capacity.

In short provision of a lift 100 which can lift' two or more carriers allows greater flexibility in some situations particularly when the two carriers wish to go to the same level. This way, two or more items on two or more carriers can use the same lift movement to reach their desired destination.

The number of carriers which can be taken in one lift movement is restricted by the lift and carrier dimensions. The lift rails need to be longer when more carriers are handled simultaneously.

Adding a second or more lifts side by side can give further additional benefits but may add to the capital cost of the sorter system.

Multiple independently driven carriers can be combined in an ad hoc manner for the purposes of carrying items larger than one carrier can handle. This requires the carriers and lift control systems to operate such that they synchronise the carrier movements keeping the carriers together whilst carrying the item to be sorted.

The temporary pairing or grouping of multiple carriers to share lift and transport movement in a sorter provides additional benefits and a wider range of products can be handled by the system within a multi-level framework. The lift mechanism is designed with elongated rails to be sufficiently large to carry the desired number of carriers simultaneously. When only one carrier uses the lift, it need only to travel as far onto the lift rails as necessary to clear the sorter framework. When two or more carriers are able to use the lift movement the first carrier moved further into the lift to leave space for the subsequent carriers. This way, the time to load the lift with one carrier is lower than the time to load two carriers. This time penalty incurred when loading additional carriers is more than offset by the time saved in the vertical lift movement.

Further the coordinated control of multiple discharge mechanisms on the independently driven carriers to manipulate the item straddling multiple carriers within a sorting system or framework of discharge chutes, totes or bags can allow optimum space utilisation and a reduction of the overall sorter length.

Figure 13 shows two carriers 302 and 303 carrying an item 300 which is longer than one carrier. The items 300 will be discharged into the chute 301 by driving the discharge belts simultaneously in the same direction towards the chute 301. The item 300 has a length which fits within the width of the chute.

Figure 14 shows how an item 300 can be carried to a destination chute 305 by two carriers 302 and 303. Prior to discharging into the chute, the item 300 is turned by driving the belt of carrier 302 away from the chute whilst simultaneously driving the belt of carrier 303 towards the chute. Once sufficiently turned the item is discharged into the chute by driving both carrier discharge belts towards the chute simultaneously. In this way an item can be sorted into a destination chute, tote or other container whilst having a length greater than the width of the chute, tote or other container. Synchronisation of the actions of the two carriers control systems is necessary to successfully carry the item without dropping it around the framework and to manipulate it into a position from which it can be successfully sorted into a chute. This synchronisation is achieved by communication between the carriers using infrared, WiFi, Bluetooth or other RF protocols. Communication can be either directly between the carriers' controllers or via the sorters other controller(s). The sorter control system decides which carriers are paired or grouped together from time to time and when carriers operate on their own.

Aspects of the present invention attempt to solve the problem of the lift in a sorting system being a capacity bottleneck by allowing, more often, multiple use of the lift movement by multiple carriers.

The sorter control system is adapted to "manufacture" lift movements to the same level based upon the upcoming items requiring transport over the lift thereby increasing the frequency that the lift carries more than one item and carrier at a time.

In an example of how the invention may be used ecommerce orders containing multiple items are picked in a warehouse from multiple mezzanine floors and areas by many operators. Each operator picks for a batch of customer orders and brings the items in a trolley to the induct of the sorter. Each individual customer order will be allocated to one of the sorting destinations and the items for that customer order sorted into the destination when the item is inducted onto the sorter. The sequence the items are brought forward to the sorter is random as the exact time each operator takes to pick his proportion of the items varies and the walking time from each warehouse area is different.

The control system may advantageously allocate order positions, within the sorter framework, at the start of a sorting period or batch in order to increase the opportunity for multiple carriers to share the same lift movement thereby increasing total real throughput of the system. Alternatively, the control system may allocate order positions progressively throughout the processing time of the batch and only commit a position when the first item for an order or collation group is being inducted onto the sorter.

A controller with a control program is provided, normally by a computer, although other types of microprocessors are also possible. When allocating progressively throughout the batch the computer program looks at the first item to be sorted and if it is not part of an order which has already been allocated to a destination slot the program will allocate an empty sortation destination on a level within the multi-level sorting system. That item is then placed by the operator onto a carrier, or carrier induct apparatus which places the item on the carrier, which approaches a lift to be taken to the correct level. The program then identifies (reads barcode) the second or subsequent item(s) and determines if its destination has already been allocated.

If neither of the first or second item has an allocated destination, then the controller is free to allocate destinations on the same level (or one on a level and the other on the induct level) allowing one lift movement to carry both the first and second carrier in one movement. When the sorter carriers move in a loop around the system all items for a destination on the induct level must first travel over the lift to any other level in order to make the journey back to the induct level where the item is sorted off.

If one of the items has a destination already allocated, then the controller may still be able to allocate a destination for the other item which allows one lift movement to take both carriers (provided there is a free destination remaining on that level or the induct level). This way two or more items on two or more carriers can use the same lift movement to reach their desired destination. Once the lift has been filled and is moving the next item becomes the first item and if it is part of an order which has no allocated destination it can be allocated to any level with empty order slots available.

The carriers may remain together when returning on the return lift or they may use the return lift separately or with other carriers.

When the orders or collation groups are allocated at the start of a batch of items to be sorted the sequence in which the items will arrive may not be known. The control system will group orders on the same level based upon probability of increasing the likelihood of manufacturing a carrier pair to use one lift movement. This can be achieved by placing the orders with the most items on the induct level. Items travelling to the sort destinations on the induct level must first move to any different level, then return back to the induct level on the return lift. This allows the control system to pair a carrier destined for the induct level with any other carrier for any other level. If orders or collation groups are randomly dispersed over a five-level system, it could be expected that circa 20% of the items would be randomly allocated to the induct level destinations. The control system could advantageously place the orders with the most items on the induct level and thereby increase the likelihood of manufacturing pairs of carriers for lift movements.

Typically, ecommerce customers order single items per order (these do not need to 35 be collated before packing and shipping so would not use the sorter) or 2, 3 or 4 or more items with decreasing frequency. Allocating all the orders with 4 or more items to the induct level and the orders with less than 3 to the other levels would result in an advantageous opportunity for pairing carriers on one lift movement. This would increase the capacity of the system where lift movements were the bottleneck of the system.

An alternative and/or additional strategy the control system can utilise is to group orders which contain the same item, on the same level. Typically, these items would be picked together by a picker in a warehouse from the same shelving location and stay together as they are brought to the sorter. They have therefore a high probability of being inducted consecutively.

The advantageous allocation of order positions, within the sorter framework, during the sorting period or batch rather than at the beginning of the batch offers further opportunity to increase the likelihood for multiple carriers to share the same lift movement thereby increasing total throughput of the system.

The system using a control system as described will be able to get a higher throughput of items to be sorted per hour as the lift movement is frequently the bottleneck when compared to a similar system using one lift movement per carrier.

Figure 8 and Figure 9 show a shuttle or sort carrier 101a, 101b which is much narrower than the shuttle of Figure 2A shown in previous embodiments. The shuttle 101a, 101b is preferred to that shown in Figure 2A as its shorter length allows for faster transfer onto lifts as there is less distance to travel. Also, when two shuttles or carriers are paired together for a lift movement the lift can be shorter than otherwise needed.

The width of the lift 100 in accordance with this embodiment of the present invention should be sufficient to allow at least two shuttles 101a, 101b to ride side by side. If the lift width is even larger than 3 or more shuttles or carriers 101a, 101b can sit side by side.

The throughput of shuttles 101a, 101b over the lift, and hence throughput potential of the whole sorting system, is limited by the cycle time to allow a shuttle 101a, 101b to get on the lift plus the time to move the shuttle(s) 101a, 101b vertically to the desired level. Once at the desired level the time taken for the shuttle(s) 101a, 101b etc. to get off the lift 100 is typically the same as the time for the next shuttle(s) or carrier(s) to get on.

Figure 10 shows a sorter system 200 with a frame 201 with a lift 100 in which carriers or shuttles 101a, 101b deliver parcels to destinations on multiple levels. Parcel 102 spans two carriers 101a, 101b whilst carriers or shuttles 201a, 201b have respective parcels or items 202, 203. The item 202 has already been inducted onto its carrier or shuttle 202 by the induct position 204. The item 203 is about to be inducted onto carrier 201b. If item 202 is required on a different level to the level of the destination for item 203 and neither of them are on the induct level, then the carriers 201a and 201b cannot share a lift movement. This situation frequently arises when the orders or collation group has already been allocated to a sort destination.

Sortation destinations are usually on both sides of the sorter and on all levels, but the sorter can have sides or levels without sort destinations. The induction positions 204 and 205 are able to be placed on any level or any side of the sorter.

As outlined above, the flexibility with the system 200 allows a number of scenarios as outlined below.

Typical Lift Cycle in a previous system with one shuttle in the lift movement. 1) First shuttle moves onto lift 0.8 sec 2) Lift moves one level 0.8 sec or, Lift moves two levels 1.2 sec and, 3) First shuttle moves off lift whilst second shuttle 2 moves on therefore, cycle time is either 0.8 + 0.8 = 1.6 seconds or, 0.8 +1.2 = 2 seconds.

In a 5-level system with a random allocation of orders to sort destinations, analysis shows that a carrier will 40% of the time move 2 levels whilst 60% of the time will move 1 level. Items for the sort destinations on the induct level need only go up or down one level to achieve the shortest path to back to the induct level.

Average cycle time is then: (0.4 *1.6) + (0.6*2) = 1.84 sec per item baseline capacity giving a sorter system throughput = 3600 sec/ 1.84 = 1956 / hour With a typical lift cycle when two shuttles go on lift at same time.

1) Both carriers or shuttles moves onto lift 1.0 sec* This is higher than before because the travel distance is greater for the two shuttles getting onto the lift acceleration and deceleration are the same and synchronized.

2) Lift moves one level 0.8 sec or, lift moves two levels 1.2 sec and, 3) Shuttle 1 and 2 moves off lift whilst shuttle 3 and 4 moves on. Therefore, cycle time is either 1.0 + 0.8 = 1.8 seconds or, 1.0 +1.2 = 2.2 seconds, assuming pairs of shuttles go to the same level all the time.

In a 5-level system, 40% of the time the lift moves 2 levels whilst 60% of the time there is a move 1 level. So average cycle time: (0.4 *1.8) + (0.6*2.2) = 2.04 sec or 1.02 sec/item System throughput = 3600 sec/ 2.04 = 1764 cycles 1764 *2 shuttles = 3528 shuttles It can be seen that the system has a higher capacity when moving 2 shuttles when compared to moving one shuttle.

With embodiments of aspects of the present invention it is possible to provide a method for the system to take advantage of the 2 shuttles using a single lift movement as an opportunity to improve efficiency. For example, assuming a "random" destination of items across the levels.

If shuttle 1 is destined for level 1 (the top level) 20% chance item on shuttle 2 is for level 1 20% chance item on shuttle 2 is for level 2 20% chance item on shuttle 2 is for level 3 the return leg of the loop back to the induction point 20% chance item on shuttle 2 is for level 4 20% chance item on shuttle 2 is for level 5 The random probability means: 40% of cycles allows 2 shuttles to utilize the lift cycle 20% from "same level" opportunity" + 20% from "return leg" opportunity Throughput is: 60% at 1956 cycles per hour + 40% at 3528 cycles per hour = 2584 items per hour It may be possible to increase the capacity further.

If item on shuttle 1 is destined for level 1 (up 2 levels to the top level) and item on shuttle 2 is destined for level 2 (i.e., also up but only one level) Cycle could be: a) 1) Both shuttles go on lift 1.0 seconds 2) lift goes up 1 level 0.8 s 3) shuttle 2 gets off 0.8 s 4) lift goes up another level 0.8 s 5) shuttle 1 gets off (shuttle 3 and/or4 gets on) 0.8 s or 1.0s (part of next cycle) Cycle time 3.4 sec for 2 items = 1.7 sec/item Marginally faster than 1.84 sec for one at a time (so better).

or...20% of the time shuttle 3 is also destined for level 2 1) Both shuttles go on lift 1.0 seconds 2) lift goes up 1 level 0.8 s 3) shuttle 2 gets off 0.8 s and shuttle 3 get on 4) lift goes up another level 0.8 s 5) shuttle 1 and 3 get off (shuttle 4/5 get on) 0.8 s Cycle time 3.4 sec for 3 items = 1.13 sec/item This is a "free ride" on the lift which improves efficiency compared to single carrier lifts in a conventional sorter system.

Note that it is likely that item 3's destination is unknown when loading 1 and 2 but a probable average cycle is (1.7*0.8)+(0.2*1.13) = 1.586 s/item or 2269/hr.

In some circumstances when taking into account the expected order or collation group profile and item profile, a three-carrier lift might be more desirable, but such lifts may add complexity, cost or have space issues. Furthermore, in a typical ecommerce warehouse, a common number of items per order is 1. Orders for 1 item do not need to go over the sorter as they can go straight to packing without being collated with other items. Orders with 2 items are common with decreasing frequency of items per order as the number of items increases.

When the order profile is like this it is possible to allocate the orders immediately and put the orders with the highest number of items on the return leg as described above. This on its own will improve the percentage of paired shuttles to above 40%.

A combination strategy of allocating the few orders with a high number of items to the return leg immediately or before the sorting starts and then allocating the remaining orders with less items progressively as the items are inducted can be utilized by the controller. This may result in an even higher system capacity.

Alternatively, the controller starts the sort and when a pair is possible with one item being for an order with a high number of items which has not been allocated yet rather than allocating both items to the same level and creating a shuttle pairing only then allocate the high item order to the return leg and if the other item is for an order with only 2 items it can be allocated to any other level.

This order profile allows a significant improvement on the percentage of paired shuttles to be above 40%. The control system is configurable to allow a variety of allocation rules taking into consideration the order and item profile and the physical characteristics of the sorter e.g., number of levels, number of destinations, speeds, and acceleration profiles of sorter components.

If the percentage of paired shuttles is 40% capacity is: (0.6 * 1956) + (0.4 * 3528) = 2584 items per hour 50% capacity is: (0.5 * 1956) + (0.5 * 3528) = 2742 items per hour 60% capacity is: (0.4 * 1956) + (0.6 * 3528) = 2899 items per hour 70% capacity is: (0.3 * 1956) + (0.7 * 3528) = 3056 items per hour Every different set of orders and different sequence of presentation of items will yield a different % of pairing opportunity.

Figure 11 shows an order profile for 8 orders (a to h) each of which contains 3 items. If we allocate the orders to destinations on a five-level sorter at the start of the sort, we get a random pattern of items for levels as we go through the sorting process. We could expect about 40% of the lift movements to be carrying two shuttles.

If we allocate the orders to destinations only when we sort the first (of the 3) items for the order, we may expect a greater number of pairs. Consider if the sequence the items are presented to sorter is: d2,e3,al,h2,g1,d1,c3,f1,f2,b3,a2,f3, g3 etc...

Allocation sequence is d2 allocated order d to level 1 position 10; e3 allocate order e to level 1 position 11 (makes a pair); al allocate order a to level 2 position 10; h2 allocate order h to level 2 position 11 (makes a pair); gl allocate order g to level 3 position 10; dl order d is already allocated but still paired with return leg opportunity as g is on return leg; c3 allocate order c to level 4; rl allocate order F to level 4 (makes a pair); f2 order F is already allocated; b3 allocate order b to level 4 (makes a pair); a2 order a is already allocated to level 2; f3 order f is already allocated to level 4 (impossible to make a pair so only one shuttle goes on lift); g3 order g is allocated to level 3 the return leg (makes a pair).

For 100 orders like these with 300 items there is likely to be a reduced chance that orders are unallocated as the items are sorted but 33% of items introduced will be the first of the order. This is not insignificant and allows the percentage of time pairs are made to be greater than the 40% expected by random chance for a 5 level system.

Note that different numbers of levels in the sorter system have different probabilities for making pairs.

The above previous order profile was simplistic and uncommon as all orders had the same number of items.

Figure 12 shows a more usual profile where the number of items per order varies.

When the order profile is like this it is possible to allocate the orders immediately and put the orders with the highest number of items on the return leg.

This on its own will improve the percentage of paired shuttles above 40%.

A combination strategy of allocating the few orders with a high number of items to the return leg immediately the sorting starts and then allocating the few item orders progressively as items are inducted can be utilized by the sorter controller.

Alternatively, start the sort and when a pair is possible with one item being for an order with a high number of items which has not been allocated yet rather than allocating both items to the same level only then allocate the high item order to the return leg. This order profile allows a significant improvement on the percentage of paired shuttles to be above 40% If the percentage of paired shuttles is 40% capacity is: (0.6 * 1956) + (0.4 * 3528) = 2584 items per hour 50% capacity is: (0.5 * 1956) + (0.5 * 3528) = 2742 items per hour 60% capacity is: (0.4 * 1956) + (0.6 * 3528) = 2899 items per hour 70% capacity is: (0.3 * 1956) + (0.7 * 3528) = 3056 items per hour Every different set of orders and different sequence of presentation of items will yield a different % of pairing opportunity.

Assuming the lift can handle multiple shuttles then operation of a system in accordance with aspects of the present invention provides the following advantages:-The belt of this shuttle should sit higher than the sides of the shuttle so that a parcel or item can sit overlapping the sides. This allows longer items to be sorted at the expense of capacity.

A sorter can be configured to sort: items whose size fits on one shuttle into standard width locations; items which fit on 2 or more shuttles into wide locations; and items which can be turned into standard width locations.

Sorting a long parcel into a normal width destination 2 shuttles can transport and sort out the long parcels into a wide location. The shuttles drive together and stop at the normal width chute and both sorter carriers drive their belts (divert mechanisms) at the same time but in opposite directions until the parcel has been turned. then both sorter carriers driven in the same direction sending the parcel into the chute, tote, bag, or other destination.

An independently driven sorter carrier is then moving within a framework which periodically combines with 1 or more other independently driven sorter carriers to move together onto or out of a lift.

An independently driven sorter carrier moving within a framework which has two or more divert mechanisms and can carry multiple items on each divert mechanism or use more than one divert mechanism to sort an item.

A sorter control system which can detect the size of an item being inducted onto a carrier and when there is sufficient space for a second item this can also be inducted onto the original carrier so that two items are carried on the same carrier together. The control system checks that the item put on first carrier are allocated to sort destinations which are on the correct side of the sorter and a suitable level so that it is not blocked from sorting of the shuttle by the second item or the control system allocates the order position to ensure sorting if one or both of the orders are unallocated to destination positions.

An independently driven sorter carrier moving within a framework can be periodically combined with 1 or more other independently driven sorter carriers to move together to carry an item which is too large for one carrier on its own.

A sorter system made up of destinations on different levels or sorter portions within a framework in which independently driven sorter carriers access the destination levels by travelling over lifts, transfers or inclined framework elements which allocates the sorter destinations to orders or groups of items to be sorted together (collated) by advantageously placing orders with a high number of items on a return or common framework element or section.

A sorter system made up of destinations on different levels of a framework in which independently driven sorter carriers access the destination levels by travelling over lifts, transfers or inclined framework elements which allocates the sorter destinations to orders or groups of items to be sorted together (collated) by advantageously placing orders which have not previously been allocated to a destination on the same level as the preceding of following item to be sorted.

A sorter system made up of destinations on different levels of a framework in which independently driven sorter carriers access the destination levels by travelling over lifts, transfers or inclined framework elements and which, allocates the sorter destinations to orders or groups of items to be sorted together (or collated) by advantageously allocating orders which have not previously been allocated to a destination on a common section or return leg of the framework where the preceding of following item to be sorted is allocated to a different level, section or destinations.

Further flexibility and capacity can be obtained by utilising a second lift positioned next to the existing lift 100 in Figure 10. Each lift could take one or more shuttles at a time and the control system may determine that the lifts move in the same or different direction simultaneously or otherwise.

Aspects of the present invention relate to a sorting system or apparatus which has at its heart a lift which can carry single of multiple carriers at a time and a controller which determines orders and possibly items sizes within that order, which may include several items such that use of multiple lifts and multiple carriers on one lift in the sorting system can overall reduce sorting time per item compared to sorting individual carriers with single lifts at one or both ends of the system. The controller processes orders and available lifts as described above to achieve, where desired, more efficient sort time per item. The process collates orders then determines are a result the desired lift combinations for better effect than single carrier lift use.

While the invention has been illustrated and described in detail in the drawings and preceding description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. Each feature of the disclosed embodiments may be replaced by altemative features serving the same, equivalent or similar purpose, unless stated otherwise. Therefore, unless stated otherwise, each feature disclosed is one example of a generic series of equivalent or similar features.

In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. Any reference signs in the claims should not be construed as limiting the scope.

Claims

Claims A sorting apparatus, the sorting apparatus including: a track arrangement including at least one sort location and having a plurality of levels; and at least a first independently driven sorter carrier and a second independently driven sorter carrier configured to carry an item to be sorted, each sorter carrier including a drive arrangement and at least one lift for the sort carriers, wherein each lift has at least one lifting platform large enough to take at least two carriers between levels simultaneously.each sorter carrier is configured to move along the track arrangement and carry an item to be sorted, and each sorter carrier further includes a discharge arrangement configured to discharge the item to be sorted at destinations on said levels, and the first sorter carrier and the second sorter carrier are configured whereby they can to be transported over the lift(s)separately or combined to be lifted by the lift together to one or more respective levels for discharge of the item(s)
2. A sorting system as claimed in claim 1 where the control system of the sorter determines the sort destination of the items inducted and groups carriers together to be transported by at least one lift when items are destined for sort destinations on the same level
3. A sorting system as claimed in claim 1 or claim 2 where the control system of the sorter determines the sort destination of the items inducted and groups carriers together to be transported by at least one lift when items are destined for sort destinations in the same direction of travel for the lift
4. A sorting system of any of the preceding claims where the control system of the sorter allocates orders or groups to be consolidated to sorter destination positions to the levels of the framework before the first item is sorted to increase the probability of grouping carriers together during the sorting process
5. A sorting system of any of the preceding claims where the control system of the sorter allocates orders or groups to be consolidated to sorter destination positions on the levels of the framework as items are identified and inducted onto the sorter to increase the probability of grouping carriers together during the sorting process
6. A sorting system of any of the preceding claims where the control system of the sorter allocates some of the orders or groups to be consolidated to sorter destination positions on the levels of the framework before the first item is sorted and the remaining orders to sorting levels and positions whilst the batch of items is being sorted and individual items are identified.
7. A sorting system of any of the preceding claims where the control system of the sorter allocates some of the orders or groups to be consolidated to sorter destination positions on the levels of the framework by allocating orders with a higher number of items to locations on the return level
8. A sorting system of any of the preceding claims where the control system of the sorter allocates some of the orders or groups to be consolidated to sorter destination positions on the levels of the framework by allocating orders with a higher number of items to locations on the level or levels which require the shortest or quickest lift movement.
9. A sorting system of any of the preceding claims where the control system of the sorter allocates some of the orders or groups to be consolidated to sorter destination positions on the levels of the framework by allocating orders with a requirement for items which appear more often than other items within the batch of orders being processed to locations on the level or levels which require the shortest or quickest lift movement.
10. A sorting system of any of the preceding claims where the control system of the sorter allocates some of the orders or groups to be consolidated to sorter destination positions on the return level and other orders to the levels which require the shortest or quickest lift movement.
11. A sorting system of any of the preceding claims where the control system of the sorter has previously allocated some of the orders or groups to be collated to sort destination positions and where one or more of the items being inducted onto a group of two or more carriers which could share a single lift movement and one or more of the items are also required by other orders selectively chooses to fulfil the order which does not result in a reduction of the probability of being able to make groups of carrier movements over the lifts later in the sorting process.
12. A sorting system of any of the preceding claims where the control system of the sorter uses the dimensions of the item to be sorted to adapt the speed of the carrier as it moves past the sort destination in order to minimise the time to discharge the item into the destination and maximise the throughput rate of the carrier.
13. A sorting system of the preceding claim 12 where the control system of the sorter uses the dimensions of the item to be sorted and the position of the item on the carrier to adapt the speed of the carrier as it moves past the sort destination in order to minimise the time to discharge the item into the destination and maximise the throughput rate of the carrier.
14. A sorting system of the preceding claim 12 where the control system of the sorter uses the dimensions of the item to be sorted and the position of the item on the carrier to adapt the speed of the carrier and the point at which discharge begins as it moves past the sort destination in order to minimise the time to discharge the item into the destination and maximise the throughput rate of the carrier.
15. A sorting system of the preceding claims 12, 13 or 14 where the control system of the sorter obtains the dimension and position information about the item from a camera or vision system.
16. A sorting system of the preceding claims 12, 13 or 14 where the control system of the sorter obtains the dimension and position information about the item from a photocell sensor system.
17. A sorting system of any of the preceding claims, wherein the first sorter carrier and the subsequent carrier(s) each have an independent belt mechanism perpendicular to the direction of the framework rail or track arrangement
18. A sorting system of any of the preceding claims, wherein the first sorter carrier and the subsequent carrier(s) each have an independent belt mechanism perpendicular to the direction of the framework rail or track arrangement
19. A sorting system of any of the preceding claims, wherein the first sorter carrier and the subsequent carrier(s) each have an independent belt mechanism perpendicular to the direction of the framework rail or track arrangement which can move in opposite directions.
20. A sorting system of any of the preceding claims, wherein the first sorter carrier and the subsequent carrier(s) each have an independent belt mechanism perpendicular to the direction of the framework rail or track arrangement which can move in opposite directions and which can adjust the position of the item on each sorter carrier by way of the discharge arrangement such that it is moved it towards the side of each sorter carrier adjacent to the or each sort location prior to arrival at the or each sort location.
21. A sorting system of any of the preceding claims, wherein the first sorter carrier and the subsequent carrier(s) are coordinated to carry a single item across more than one carrier.
22. A sorting system of any of the preceding claims, wherein the first sorter carrier and the subsequent carrier(s) are coordinated to carry a single item across more than one carrier and prior to discharging into a sort destination can adjust the position of the item on each sorter carrier by way of the discharge arrangement such that it is moved it towards the side of each sorter carrier adjacent to the or each sort location prior to arrival at the or each sort location.
23. A sorting system of any of the preceding claims, wherein the first sorter carrier and the subsequent carrier(s) are coordinated to carry a single item across more than one carrier and prior to discharging into a sort destination can reposition the item by driving the discharge belts in different directions to turn the item.