GB2608793A

GB2608793A - A sorting and sequencing method and apparatus

Info

Publication number: GB2608793A
Application number: GB2109384.4A
Authority: GB
Inventors: John Hyslop David
Original assignee: Hysort Ltd
Current assignee: Hysort Ltd
Priority date: 2021-06-29
Filing date: 2021-06-29
Publication date: 2023-01-18
Also published as: GB202109384D0

Abstract

A sorting system uses independently controlled sorting carriers (21 fig.2a), such as shuttles, which travel through a multilevel framework (fig.3) to sorting destinations on one or more levels. The sorter carriers are configured to vary the point at which they discharge an item, in which a system controller uses the item dimensions and position on the sorting carriers to calculate the discharge position in the framework. Thus, items later in a sequence may be positioned behind earlier sequenced items on a chute so that the items can be unloaded from the chute in the correct order.

Description

A SORTING AND SEQUENCING METHOD AND APPARATUS

Description

This specification relates to package sorting. In particular, although not exclusively, this specification relates to systems and methods for sequencing and/or ordering of packages.

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 of 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). Once in a destination chute items are unlikely to overtake however, they are uncontrolled and when a smaller item has room to pass a larger item this may happen. The sequence of items presenting at the end of a chute, or other type of destination, is generally the same as the sequence of induction onto the sorter.

Many sorting machine users have a desire to sequence items to simplify downstream operations. -2 -

It is therefore, desirable for a sorting machine to be able to sequence the items sorted.

An aspect of the invention provides a sorting system configured to use independently controlled sorting carriers which travel through a framework to sorting destinations on one or more levels, wherein the sorter carriers are configured to vary the point at which they discharge an item, the system further including a system controller which is configured to use the item dimensions and position on the sorting carriers to calculate the discharge position in the framework for the sorting carrier to discharge the item allowing a high density of filling of the chute.

Preferably, the items are placed side by side in the chute, with minimum space between, allowing the parcels to be removed from the front of the chute in the desired sequence whilst taking up a minimum width of sort chute within the framework.

Conveniently, the items position is communicated back to the sorter controller and then made available to and used by the operator or unloading device to pick the items in the predefined sequence.

Advantageously, at the point of discharge, the speed of forward motion of the sorting carrier is variable from zero up to the carrier top speed.

Preferably, the system controller determines the optimum sorting carrier speed at the point of discharge.

Conveniently, the sorter controller is configured to take account of the item dimensions and position on the sorter carrier to vary the speed of forward motion of the sorter carrier at the point of discharge from zero to the top speed of the sorter carrier.

Alternatively, the sorter carrier is configured to take account of the dimensions and positions of items already sorted and the item dimensions and position on the sorter carrier of the current item to be sorted to determine the optimum position and forward speed of the sorter carrier at the point of discharge. -3 -

Advantageously, the sort destination in the framework is pre allocated based upon the item dimensions and quantities known for the next sorting period, or on the historically expected item dimensions and quantities with a suitable allowance for reasonable variation.

Preferably, the pre allocation of space for each sort destination in the framework levels allows items to be sorted close by each other thus minimising the destination chute width required and the walking of the unloading operator.

Conventiently, the sorting system further includes an overflow chute or level which can be used where the actual item quantities and and/or dimensions exceed the expected level.

Advantageously, the sorter control system uses the item dimensions, position on the carrier and known desired item sequence to place items into the sort destination chute.

Preferably, the position in the sort destination chute is behind other items already sorted with a lower position in the desired sequence where the framework length and item dimensions allow.

Conveniently, the items position in the chute is communicated back to the sorter controller and then used by the controller and/or operator to pick the items in the predefined sequence.

Advantageously, the desired sequence of removal from the chute is communicated to the operator by a laser or light pick pointer.

Preferably, the desired sequence of removal from the chute is communicated to the operator by a light or series of lights on the chute framework where the number and position of lights activated is in line with the position of the item to be removed next in the sequence. -4 -

Conveniently, the desired sequence of removal is communicated to the operator by screen or monitor displaying a picture of the item to be removed.

Alternatively, the desired sequence of removal from the chute is communicated to the operator by a combination of the features described above.

Advantageously, the sorting carriers are captive within the framework.

A sorter using independently driven carriers within a framework of one or more levels has the ability to sort items into destination chutes allowing an operator to remove the items in a desired sequence from the front of the chutes whilst minimising the overall length of the sorter. It is envisaged that the independently driven carriers may be captive within the framework, and may be constrained only to move therewithin.

The sorter controller uses the item dimensions and/or position on the carrier to determine the optimum discharge point within the framework (and the optimum speed of forward movement of the carrier at the point of discharge of the item, this can range from zero to the top speed of the carrier). The sorter controller also uses the desired sequence of the items and the position within that sequence of each item sorted to determine the sort position of the next item to be sorted.

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 la shows a prior art sorting apparatus with long destination chutes; Figure lb shows a prior art sorting apparatus with a wider chute; Figure 2a shows an exemplary sorter carrier within which the present invention may be deployed; -5 -Figure 2b shows an alternative, exemplary sorter carrier within which the present invention may be deployed; Figure 3 shows a diagrammatic representation of an exemplary sorting machine using a number of carriers within a framework within which the present invention may be deployed; 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 diagrammatic representation of the top view of a carrier which has sorted items keeping items higher up in the sequence behind items lower in the sequence allowing items to be removed from the chutes in the desired sequence.

Figure 6 shows a diagrammatic representation of the side view of a carrier which has sorted items keeping items higher up in the sequence behind items lower in the sequence allowing items to be removed from multiple level chutes in the desired sequence.

Referring firstly to Figure la, there is shown a conventional sorter with destination chutes where items are not sequenced.

In Figure la, the chutes have a 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 being sorted are placed in the chute largely in the sequence of induction onto the sorter (if a chute is blocked at the time an item is ready to be sorted it can be recirculated and sorted into the chute the next time around). Any overtaking in the chute is uncontrolled and unlikely.

In this conventional chute the operator cannot access the parcels in the desired sequence 1, 2, 3.. etc. as the items further up the chute are blocked by the items immediately in front of the operator.

Figure lb shows an alternative way of presenting the operator at the end of a chute with the ability to load in a predefined sequence. This example has a very wide -6 -chute, but not as necessarily as long, where items are sorted across width of the chute so that all item can present at the end, in front of the operator, and be accessed in sequence. This wide chute has multiple fixed discharge points, in the same way the sorter in Figure la has, where the sorter controller can eject an item.

This results in a number of fields over the width of the sort destination chute where items can land when sorted. Effectively multiple narrower chutes are combined to make one super wide chute for each sort destination. Small items sorted in this way use the same width of chute as wider items resulting in gaps between smaller items and underutilisation of the chute width.

This solution is poor because the operator has to walk along the wide chute to reach the items. Such a sorter has extremely poor floor space utilisation and is expensive due to its long length.

Two example scenarios will now be discussed, in which prior art sorting apparatuses may be employed.

In a first example scenario, a parcel handling company may receive a large lorry full of randomly loaded parcels and unload the lorry onto a sorting machine which sorts to multiple vans for onward customer delivery. The vans are given an efficient route based upon the delivery addresses of the parcels. Ideally the van would be loaded in reverse drop sequence so that the driver did not have to hunt for parcels at each delivery stop. On a conventional sorting machine, the chutes fill up with a sequence of parcels generally sequenced as they are unloaded from the lorry resulting in imperfect sequence of van loading or a laborious time consuming secondary manual sequencing process prior to loading the delivery van.

In a second example scenario, a book distribution warehouse replenishes multiple retail outlets with books, either picked from stock or just arrived at the warehouse, by sorting the books on a sorter with multiple destination chutes each representing one retail store. The picking and book delivery process results in a random and imperfect sequence of books being inducted onto the sorting machine and so an imperfect sequence in each chute. At the end of the chutes the books are packed into large cartons and dispatched to the retail store. In the retail store the operator wishes to -7 -load the shelves by genre and then alphabetical order of author but the carton he opens has books in a random or imperfect order as that is how they were presented in the chute of the sorter. This makes the stocking of shelves more time consuming.

It is therefore desirable to address these issues.

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.

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 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.

In the case of the sorter carrier 21 shown in Figure 2a, the wheels are fixed, that is to say that they are not capable of 'steering'. Such a sorter carrier 21 may, for example, -8 -include one or more steering axes to enable the wheels of the sorter carrier 21 to steer and thus the sorter carrier 21 be able to move along curved rails.

In addition, the sorter carrier 21 may be low profile, that is to say the overall height of the sorter carrier may be minimised, to allow for an item with a large height to be transported on the sorter carrier 21. As can be seen from the rail arrangement of the sorting machine in Figure 3 (discussed below), a first sorter carrier 21 may need to pass under a moving further sorter carrier 21, and if an item with a large height is to be moved within the sorting machine, there is a possibility that the top of the item may foul or catch on the sorter carrier 21 moving thereabove.

It may therefore be advantageous for the overall height of the sorter carrier 21 to be relatively low in order to avoid collisions with other sorter carriers 21 in a sorting machine.

Turning now to Figure 2b, there is shown an alternative carrier with tank tracks instead of wheels. On this version a timing belt 25 (the tank track) is driven between the wheels 26 (drive pulleys) giving a large contact area with the rail. If needed multiple wheels/pulleys can be placed along the length of the track to press the belt down against the rail.

It is envisaged that such an alternative carrier may be used in a sorting machine which may employ a continuous track, that is to say that the track forms a loop or circuit. Such a track may also be sloping, curved, or multi-level. In a situation where the track is multi-level, a curved, inclined, or curved an inclined track may be used to allow the sorter carrier to move between levels of the machine. Such a track may be used as an alternative to the lift shown in Figure 3 and discussed below.

It is also envisaged that a sorter carrier 21 similar to that shown in Figure 2a may be used in a sorting machine having a continuous track, with the sorter carrier 21 having steering axles on the wheels thereof to allow the sorter carrier 21 to move around curved sections of the machine.

Figure 3 shows a sorting machine utilising multiple carriers 31 which travel over multiple levels 32 using lifts 33. The carriers can stop or slow down at any desired -9 -sorting point to discharge the item to be sorted into a chute arranged perpendicular or at an angle to the direction of travel of the carriers at each level of the sorter. The chute is not shown. The sorter carrier takes into account the position previously sorted items were placed into the chute, the dimensions of the item to be sorted and the position the item has taken up on the carrier to determine the optimum position to discharge the item and if possible, what forward speed the carrier may move at. Frequently the carrier forward speed will be zero to ensure good positional accuracy of the item when sorted.

The item induct position can be anywhere along the length of the sorter and is not shown in Figure 3.

Figure lb demonstrates that it is possible for a conventional sorter to sort items with a desired sequence into fixed chutes and presenting the items to the operator in such a way that they can be removed in the desired sequence i.e. 1, followed by 2, followed by 3, and then 4, 5, 6, and then 7.

This occupies a large amount of space and the operator needs to walk a long way to unload the chutes.

Turning now to Figure 4, there is shown an example of where a sorter carrier which contains the invention has placed parcels in a chute. By taking account of the width of the item and the position the item was placed on the sorter carrier the carrier can discharge an item into a chute to take advantage of any space remaining in the width of the chute following the sortation of an earlier item.

Where the number and desired sequence of removal of the items is known for each sort destination, prior to the sort taking place, the sorter controller can utilise remaining space in the length of a chute by placing an item which is higher in the sequence of removal behind an earlier sorted item The item marked 2 in Figure 5 has had an item marked 5 placed behind it. The sorter will place the first item (parcel 2) into the chute and store the dimensions and position data of that item. Items of various sizes may be placed adjacent to the first item into the chute and their size and position (parcels 3 and 1) stored by the sorter controller.

When an item is inducted onto a carrier whose position in the sequence is lower (i.e., it needs to be unloaded from the chute before the other items sorted) that item will also be allocated to a position where the item will fall to the front of the chute with no other item preventing the operator removing it first. When an item is inducted onto a carrier (parcel 5) whose position in the sequence for removal is higher than that of an item already in the chute the sorter controller will determine if it can place the item behind the item already in the chute. The controller will use the data stored about the size and position of the items already in the chute, the size and position of the item on the carrier and the overall length, width and chute design to determine if it will fit behind any items already in the chute. Only items higher in the desired sequence may be placed behind lower sequence items. When the lower sequenced items at the front of the chute are removed the item behind can move forward in the chute and removed when the operator has removed all of the other items lower in the sequence.

If more than one position in the chute behind a number of items is possible the carrier will use the position behind the item with the highest position in the sequence as this leaves the items with a lower position in the desired removal sequence available for the remaining items.

An alternative strategy would be to use as much space or capacity in each chute when selecting which chute to select. This may be of importance when seeking to optimise space utilisation.

Where an item inducted onto a carrier is wider than one item already in the rack it can be placed into the rack behind two or more adjacent items provided, they all have a position in the sequence lower than the new item.

When the operator removes items from the front of the chute in the desired sequence the parcels behind roll, slide, or are moved forward so that they can be accesses in turn.

The sorter controller may be configured periodically to have fixed framework positions for each sorter destination. By way of an example, parcel sorter sorting to van rounds may allocate a first van to the same 2m section of the framework of the sorter across all levels. A second van may be allocated to the adjacent section of the framework, with a third van next to that, and so on as desired.

This will be the same for the next day, week etc until the sorter is reconfigured.

These chute positions will most likely utilise a physical part of the framework (e.g. a supporting column or separation plate) to separate items from the adjacent sort destination. If over a period of time the relative volume of items for the round of the first van is reduced but the round of the second van increases the widths of chute or number of chute levels allocated to each van round could be adjusted in the sorter controller's configuration.

It is possible to have a destination utilise a width of 2m on 4 levels whilst allowing the 5th level to be allocated to a different sort destination. Most likely the adjacent sort destination. In any given sorting period the number of items for a sort destination, the dimensions of the items and the sequence they will be inducted will vary. As a result, the widths of chute will likely be configured to leave some extra space for a variation in the number or size of items for any given sort period or shift. In extreme cases this extra or contingency space may not be enough and overflow items will be sent to a predefined rework area where they can be manually processed for later consolidation with the remainder of the items for the sort destination.

Where the number and size of items for a destination is known the minimum volume of chute could be calculated. However, the random or imperfect sequence that the items will be inducted onto the sorter means that this minimum volume is extremely unlikely to be enough to take all items particularly where items to be removed first are inducted towards the end of the sort period. By determining the likely number and size of items for a given sort destination a volume of chute can be calculated, taking into account the width, length and number of levels which gives a high statistical probability the chute will be large enough for a random induct sequence for an acceptable number of sorting shifts. The overflow area and operation can be minimised by increasing the extra or contingency space allocated per destination cute. Following an analysis of the historic size and numbers of parcels for a van round or store it may be possible to determine that 20% extra space in each destination chute will be sufficient 95% of the time without the need to send a parcel to the overflow or 30% extra space sufficient 99% of the time.

Alternatively, the sorter can dynamically allocated sort destinations at the start of each sorting period where the number and size of items is known by a host system and communicated along with the desired sequence and where the sequence of induction to the sorter is imperfect or random. The items will still be inducted in the imperfect sequence and placed into the dynamically allocated chute. In extreme cases the volume of chute allocated may still not be big enough or the sequence particularly unfavourable and an overflow area may be utilised.

Figures lb, 4, 5, and 6 show how a randomly inducted set of items (marked 1 to 7) may be sorted in a progressively more space-efficent manner. In the examples shown in Figures lb, 4, 5, and 6, a randomly inducted set of items which traditionally requires 7m of chute width and sorter length can be sorted into a lm width over 5 levels whilst maintaining the ability of the operator to unload them from the chute in the desired sequence by a multi-level sorter with independently driven carriers utilising the invention. It is to be understood that other scenarios are envisaged, and that the length and number of levels required may be in dependence upon a number of factors.

Figure lb shows what may be achieved with a conventional sorter. Progressing from this, Figure 4 shows what can be achieved by measuring dimensions and position of the item on the carrier and using the carrier to adjust the position of sorting to take advantage of the width of the items. Figure 4 shows that the same items may be sorted into a narrower area than that shown in Figure lb. Figure 5 shows that the same items can be sorted into an even narrower area by allowing items higher in the desired sequence to be placed behind items lower in the sequence and Figure 6 shows the arrangement of parcels in Figure 5 when the chute area is allocated vertically.

Comparing to the scenario demonstrated in Figure lb where the operator must remove items from a very wide area, the operator in figure 6 has a much narrower chute area and can remove the items in sequence without much walking. Therefore, in the example solution shown in Figure 6, the overall area needed for the sort destination is reduced, and this arrangement may improve operator productivity.

When the removal of the items from the chute is required either at the end or during the sorting process an operator attends the front of the destination chute. The sequence of items to be removed is indicated by the sorter controller to guide the operator to carry out the task in the desired sequence. A row of light bulbs or LED's may be attached to the front of the framework at each level, with the lights spaced along the width of each chute is shown on Figure 6.

The lights 61 corresponding to the position of the next item in the sequence to be removed are activated by the sorter controller taking into account the level, position along the width of the chute and width of the parcel. A wide item has more lights activated than a narrow item. Alternatively, a light pointing device can shine onto the level and position along the destination chute width of the next item to be removed. Additionally, a monitor may display a picture, either taken at the point if induction or earlier, of the item to assist the operator to identify the item. Once an item has been removed the controller may detect this with a sensor. Alternatively, an operator may push a button or scan a barcode making the controller aware the item has been removed and it indicates the next item to be taken.

Conventional sorters on the market use a fixed speed of carrier moving past destinations and do not stop at the destination. This prevents them placing items immediately adjacent to other items or between the gaps created by existing items in the chute.

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 alternative 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 system configured to use independently controlled sorting carriers which travel through a framework to sorting destinations on one or more levels, wherein the sorter carriers are configured to vary the point at which they discharge an item, the system further including a system controller which is configured to use the item dimensions and position on the sorting carriers to calculate the discharge position in the framework for the sorting carrier to discharge the item allowing a high density of filling of the chute.
The sorting system of claim 1, wherein the items are placed side by side in the chute, with minimum space between, allowing the parcels to be removed from the front of the chute in the desired sequence whilst taking up a minimum width of sort chute within the framework.
The sorting system of claim 1 or claim 2, wherein the items position is communicated back to the sorter controller and then made available to and used by the operator or unloading device to pick the items in the predefined sequence.
The sorting system of any preceding claim, wherein at the point of discharge, the speed of forward motion of the sorting carrier is variable from zero up to the carrier top speed.
The sorting system of any preceding claim, wherein the system controller determines the optimum sorting carrier speed at the point of discharge.
The sorting system of any preceding claim, wherein the sorter controller is configured to take account of the item dimensions and position on the sorter carrier to vary the speed of forward motion of the sorter carrier at the point of discharge from zero to the top speed of the sorter carrier.
The sorting system of any one of claims 1 to 5, wherein the sorter carrier is configured to take account of the dimensions and positions of items already sorted and the item dimensions and position on the sorter carrier of the current item to be sorted to determine the optimum position and forward speed of the sorter carrier at the point of discharge.
The sorting system of any preceding claim, wherein the sort destination in the framework is pre allocated based upon the item dimensions and quantities known for the next sorting period, or on the historically expected item dimensions and quantities with a suitable allowance for reasonable variation.
The sorting system of claim 8, wherein the pre allocation of space for each sort destination in the framework levels allows items to be sorted close by each other thus minimising the destination chute width required and the walking of the unloading operator.
10. The sorting system of claim 9, further including an overflow chute or level which can be used where the actual item quantities and and/or dimensions exceed the expected level.
11. The sorting system of any preceding claim, wherein the sorter control system uses the item dimensions, position on the carrier and known desired item sequence to place items into the sort destination chute.
12. The sorting system of claim 11, wherein the position in the sort destination chute is behind other items already sorted with a lower position in the desired sequence where the framework length and item dimensions allow.
13. The sorting system of claim 12, wherein the items position in the chute is communicated back to the sorter controller and then used by the controller and/or operator to pick the items in the predefined sequence.
14. The sorting system of any preceding claim, wherein the desired sequence of removal from the chute is communicated to the operator by a laser or light pick pointer.
15. The sorting system of claim 14, wherein the desired sequence of removal from the chute is communicated to the operator by a light or series of lights on the chute framework where the number and position of lights activated is in line with the position of the item to be removed next in the sequence.
16. The sorting system of claim 14, wherein the desired sequence of removal is communicated to the operator by screen or monitor displaying a picture of the item to be removed.
17. The sorting system of any one of claims 14 to 16, wherein the desired sequence of removal from the chute is communicated to the operator by a combination of the features of at least two of the features of claims 14 to 16.
18. The sorting system of any preceding claim, wherein the sorting carriers are captive within the framework.