Title: Flats sequencing system and method of use
Abstract: A system and method sequencing objects in trays by assigning a direction to tray locations, where each of the tray locations provides space for trays. The objects are placed into the trays corresponding to assigned directions of the objects. A determination is made as to whether there are additional objects that correspond to the direction and, if so, the direction is assigned to unassigned tray locations based on pre-defined rules. Once all of the objects are in the trays, the trays are moved to the feeder system in a sequential order based on the directions. In a second pass, the directions are reassigned to the tray locations based on a number of trays required to hold the objects. The objects are placed into the trays corresponding to the directions of the objects. The trays are then transported to an unloading stage in a sequential order corresponding to the reassigned directions.
Patent Number: 6,881,916 Issued on 04/19/2005 to McLaughlin, et al.
| Inventors:
|
McLaughlin; Jason G. (Owego, NY);
Wisniewski; Michael A. (Owego, NY)
|
| Assignee:
|
Lockheed Martin Corporation (Bethesda, MD)
|
| Appl. No.:
|
365639 |
| Filed:
|
February 13, 2003 |
| Current U.S. Class: |
209/584; 209/900; 198/349 |
| Intern'l Class: |
B07C 003//00; B65G 047//00 |
| Field of Search: |
209/583,584,900
198/349,350
|
References Cited [Referenced By]
U.S. Patent Documents
| 5246332 | Sep., 1993 | Bernard, II et al.
| |
| 5353938 | Oct., 1994 | LaGrange et al. | 209/584.
|
| 5385243 | Jan., 1995 | Jackson et al. | 209/509.
|
| 5421464 | Jun., 1995 | Gillmann et al. | 209/584.
|
| 5472309 | Dec., 1995 | Bernard, II et al.
| |
| 5901855 | May., 1999 | Uno et al.
| |
| 5994657 | Nov., 1999 | Maier et al.
| |
| 6316741 | Nov., 2001 | Fitzgibbons et al.
| |
| 6741908 | May., 2004 | Vanderbles et al. | 700/224.
|
| 2002/0125177 | Sep., 2002 | Burns et al. | 209/630.
|
| 2003/0141226 | Jul., 2003 | Morikawa | 209/584.
|
Primary Examiner: Walsh; Donald P.
Assistant Examiner: Rodriguez; Joseph C
Attorney, Agent or Firm: McGuireWoods LLP
Claims
What is claimed is:
1. A method of sequencing objects in trays located at tray locations of bin
sections, comprising the steps of:
pre-assigning a direction to tray locations, where each of the tray
locations provides space for trays;
providing an unassigned designation to at least one tray location of the
tray locations, the at least one tray location providing tray space such
that placement of objects therein remain in sequence;
placing the objects into the trays of the tray locations with the direction
corresponding to assigned directions of the objects;
determining whether there are additional objects requiring placement which
correspond to the direction and, if so, assigning the direction to an
unassigned tray location based on pre-defined rules and placing the
objects in the trays of the subsequently assigned tray locations; moving
all of the trays with the objects to a feeder in sequential order based on
the direction associated with each moved tray;
reassigning the direction in a sequential order to the tray locations based
on a number of trays required to hold the objects;
placing the objects into the trays of the tray locations with the
reassigned direction corresponding to the directions of the objects; and
transporting the trays with the objects to a loading area in a sequential
order corresponding to the reassigned direction.
2. The method of claim 1, wherein:
the assigned direction is a set of delivery or storage points; and
the reassigned direction is a set of sequenced delivery or storage points;
the sequential order in the reassigning step provides for a lower number
reassigned direction to be in front of a higher number reassigned
direction for unloading;
the direction includes a same direction or different directions; and
the unassigned tray locations include at least one of (i) the at least one
tray location having the unassigned designation and (ii) a previously
assigned tray location which is now empty due to the tray being filled and
moved.
3. The method of claim 1, wherein
the tray locations include at least one front tray location and at least
one back tray location;
the tray locations are positioned in one or more partitions; and
at least one front tray location of each partition includes the unassigned
designation.
4. The method of claim 3, wherein the moving step includes the steps of:
(i) determining whether a front tray in the front tray location is filled
with objects for a pre-assigned direction;
(ii) determining whether a transporting system is empty in front of the
front tray;
(iii) determining whether a lower direction assigned tray will be blocked
by moving the front tray onto the transporting system; and
(iv) moving the front tray onto the transporting system when steps (i) and
(ii) are positive and step (iii) is negative.
5. The method of claim 4, further including the step of waiting until the
first pass is complete when at least one of the step (ii) is negative and
step (iii) is positive.
6. The method of claim 4, further including the step of moving a back tray
to the front tray location and, if required, placing an empty tray at the
back tray location.
7. The method of claim 1, wherein the determining step includes assigning a
same direction to a further tray when a previous tray is filled with
objects for the same direction and additional objects having the same
direction requiring placement.
8. The method of claim 7, wherein the determining step assigning the
direction to tray locations includes the steps of:
scanning in a sweep direction starting with the location of the previous
filled tray having the same direction;
determining whether the scanned tray location has a filled tray; and
assigning the scanned tray location the same direction when the tray of the
scanned tray location is not filled.
9. The method of claim 7, wherein the determining step assigning the
direction to tray locations includes the steps of:
scanning in a sweep direction starting with the location of the previous
filled tray having a same direction;
determining that the scanned tray location has a filled tray;
scanning in the sweep direction from the filled tray location;
determining whether a next front tray location is free and all trays on a
transporting system in front of the next front tray location toward the
sweep direction have a lower or equal direction as the same direction; and
assigning the same direction to the next front tray location when the front
location is free and all trays on the transporting system towards the
sweep direction have the lower or equal direction.
10. The method of claim 7, wherein the determining step assigning the
direction to tray locations includes the steps of:
(i) scanning in a sweep direction starting with the location of the
previous filled tray having a same direction;
(ii) determining that the scanned tray location has a filled tray;
(iii) scanning in the sweep direction from the filled tray location;
(iv) determining that a next front tray location is not free or all trays
on a transporting system in front of the next front tray location toward
the sweep direction have a lower or equal direction to the same direction,
or both;
(v) determining whether a next back tray location, located behind the next
front tray location, is free and the next front tray location has the
lower or equal direction; and
(vi) assigning the same direction to the next back tray location when the
step (v) is positive.
11. The method of claim 1, wherein the reassigning step includes assigning
pre-assigned directions to the tray locations based on:
(i) recorded data used in the first pass;
(ii) scanning away from a sweep order; and
(iii) assigning a direction to a first available tray location in a
direction away from the sweep order starting with a lowest direction.
12. The method of claim 11, wherein the reassigning step further includes
the steps of:
determining whether there are more than two trays in a same direction; and
assigning the same direction to a next available tray location, always
filling a front tray location first, when there are not more than two
trays in the same direction.
13. The method of claim 11, further comprising the steps of:
determining that there are more than two trays in a same direction;
setting a bin location to a next bin location where all tray locations are
free;
assigning the same direction to all transporting system positions between
and including the preset bin location and the preset bin location-(number
of trays in the same direction-X); and
assigning all required tray locations to the preset bin location-(number of
trays in the same direction-X),
wherein X is a number of tray locations and transporting system positions
per bin location.
14. The method of claim 13, wherein X=3.
15. The method of claim 13, wherein when the preset bin location-(number of
trays per direction-X)<0, all left over directions are assigned to any
available back tray location.
16. A method of sequencing objects in trays located at tray locations of
bin sections, comprising the steps of:
pre-assigning directions to tray locations;
placing an object in a tray in one of the tray locations such that each
placed object is related to one of the directions of the tray locations in
which the objects are placed;
moving filled trays with the objects through the feeder system in
sequential order based on the directions;
reassigning the direction to the tray locations based on a number of trays
required to hold the objects in the reassigned direction;
placing the objects into the trays at the tray locations associated with
the reassigned directions; and
transporting the trays with the objects to an unloading area based on a
sequential order of the reassigned directions.
17. The method of claim 16, further comprising the step of providing at
least one front tray location with an unassigned designation prior to the
moving step.
18. The method of claim 16, further comprising the step of providing an
unassigned designation to an empty tray location after the moving step
and, if further objects with the direction are present, assigning the
direction to the unassigned designation based on predefined rules.
19. The method of claim 16, wherein the moving step includes determining
whether lower assigned direction trays remain unblocked and, if so, then
moving the tray onto a transporting system.
20. The method of claim 16, further comprising the step of determining
whether there are additional objects requiring placement which correspond
to the direction and, if so, assigning the direction to an unassigned tray
location for placement of the additional objects.
21. The method of claim 20, wherein the determining step includes the steps
of:
scanning in a sweep direction starting with a previous filled tray having a
same direction;
determining whether the scanned tray location has a filled tray; and
assigning the scanned tray location the same direction when a tray of the
scanned tray location is not filled.
22. The method of claim 20, wherein the determining step includes the steps
of:
scanning in a sweep direction starting with a location of a previous filled
tray having a same direction;
determining that the scanned tray location has a filled tray;
scanning in the sweep direction from the filled tray location;
determining whether a next front tray location is available and trays on a
transporting system in front of the next front tray location toward the
sweep direction have a lower or equal direction as the same direction; and
assigning the same direction to the next front tray location when the front
location is available and trays on the transporting system towards the
sweep direction have the lower or equal direction.
23. The method of claim 20, wherein the determining step includes the steps
of:
(i) scanning in a sweep direction starting with the location of a previous
filled tray having a same direction;
(ii) determining that the scanned tray location has a filled tray;
(iii) scanning in the sweep direction from the filled tray location;
(iv) determining that a next front tray location is not free or all trays
on a transporting system in front of the next front tray location toward
the sweep direction have a lower or equal direction to the same direction,
or both;
(v) determining whether a next back tray location, located behind the next
front tray location, is free and the next front tray location has the
lower or equal direction; and
(vi) assigning the same direction to the next back tray location when the
step (v) is positive.
24. The method of claim 16, further including the step of providing
unassigned tray locations to at least one of (i) a tray location having an
unassigned designation and (ii) a previously assigned direction tray
location now empty due to the tray being moved.
25. The method of claim 24, wherein the reassigned direction is a set of
sequenced delivery or storage points and the sequential order in the
reassigning step provides for a lower number reassigned direction to be in
front of a higher number reassigned direction for unloading.
26. The method of claim 16, wherein the moving step includes the steps of:
(i) determining whether a front tray in a front tray location is filled
with objects for a preassigned direction;
(ii) determining whether a transporting system is empty in front of the
front tray;
(iii) determining whether a lower direction assigned tray will be blocked
by moving the front tray onto the transporting system; and
(iv) moving the front tray onto the transporting system when steps (i) and
(ii) are positive and step (iii) is negative.
27. The method of claim 26, further including the steps of at least one of:
waiting to move trays having objects therein when at least one of the step
(ii) is negative and step (iii) is positive; and
moving a back tray to the front tray location and, if required, placing an
empty tray at the back tray location.
28. The method of claim 27, wherein the reassigning step includes the steps
of:
determining whether there are more than two trays in a same direction; and
assigning the same direction to a next available tray location, always
filling a front tray location first, when there are not more than two
trays in the same direction.
29. The method of claim 27, further comprising the steps of:
determining that there are more than two trays in a same direction;
setting a bin location to a next bin location where all tray locations are
free;
assigning the same direction to positions between and including the preset
bin location and the preset bin location-(number of trays in the same
direction-X); and
assigning all required tray locations to the preset bin location-(number of
trays in the same direction-X),
wherein X is a number of tray locations and transporting system positions
per bin location.
30. The method of claim 29, wherein when the preset bin location-(number of
trays per direction-X)<0, all left over directions are assigned to any
available back tray location.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a sequencing system and method
of use and, more particularly, to a sequencing system and method of use
for flats and other objects.
2. Background Description
In view of increased demand on postal systems, worldwide, it has become
very important to automate the sorting and delivery sequence of mail
products such as magazines, newspapers, packages and other articles or
flats. These automated processes must be able to sort the mail pieces in a
delivery sequence so as to enable a postal carrier the ability to deliver
the mail pieces in the most efficient route. This translates into less
carriers needed to cover the number of delivery points along each delivery
route. This ultimately reduces costs while increasing the productivity of
the carrier. Without the automated processes, it would be virtually
impossible for the postal system such as the United States Postal Service
(USPS) to efficiently delivery the flats in a time sensitive and cost
efficient manner.
Initially, the mail pieces are provided in random order to the postal
service prior to being sequenced. In the past, these mail pieces were
manually sequenced, but these manual processes were labor intensive and
quite inefficient. This has led to the advent of automated systems, with
much efficiency now being borne into the system. In the automated
processes, increased accuracy and speed has become possible using bar code
readers, feeding systems and transport systems and the like. In one type
of automated system, for example, a multiple pass process is utilized
which requires a first pass for addresses to be read by an optical
character reader and thereafter the use of a multiple-pass sorting
process. In the first pass, the mail pieces are separated into bins or
holding trays and multiple further passes are used to reach a delivery
sequence order. The bar-code labeling process and additional sorting steps
required, however, involves additional processing time and sorting machine
overhead as well as additional operator involvement to reach the result of
delivery order sequence.
By way of one example, an automated system using a two pass algorithm is
used to sort and sequence mail pieces. In this system, bar code readers
and transport systems are used, but many shortcomings become apparent when
using this type of system. For instance, the bar-code labeling process and
additional sorting steps involves additional processing time, the need for
sorting holding bins and additional operator involvement. Also, it is
known that the sorting steps are prone to error thus leading to improper
sequencing of the mail pieces, as the final product.
By use of a specific example to illustrate these shortcomings, a
carousel-type system is able to handle approximately 40,000 pieces of mail
per hour, and uses different holding trays for different set of delivery
points. In using this type of system, each holding tray is provided in a
bin section which is only capable of placement of a single holding tray.
With this system, due to the limits of the holding tray placement spots
and other shortcomings, the holding trays cannot be sequenced on the
carousel, itself, but must be taken from the carousel, stored within a
large storage area (flooring space), sorted, and returned to the carousel
for a second pass. In the sorting process, many sorting errors result
which reduces the efficiency of the system and leads to improper
sequencing of the mail pieces.
Referring again to the specific example utilizing a two pass algorithm,
directions are assigned to a set of delivery points, all of which are
assigned to each partition in the carousel. Taking four directions with 16
delivery points, for example, a first portion of the algorithm may assign
the following directions to each delivery point:
Direction #1 1 5 9 13
Direction #2 2 6 10 14
Direction #3 3 7 11 15
Direction #4 4 8 12 16
That is, in row #1 (direction 1) there are delivery points for 1, 5, 9 and
13. In row #2, (direction 2) there are delivery points for 2, 6, 10 and
14. In row #3 (direction 3), there are delivery points for 3, 7, 11 and
15. Lastly, in row #4 (direction 4), there are delivery points for 4, 8,
12 and 16.
However, these sets of delivery points are not in any particular order.
Also, due to the large volume of mail pieces assigned to a particular
direction, it is necessary to have several holding trays for a particular
number of mail pieces associated with a delivery point. But, in such an
assignment, when the holding trays become filled, it is necessary to
remove the holding trays from the carousel, place an empty holding tray at
the respective bin section and continue filling the holding tray for that
direction. When the holding tray is removed, though, it must be stored in
a storage area until all of the holding trays are filled or all of the
mail pieces for the particular carousel run have been placed in the
respective holding trays. As can be imagined, this takes an enormous
amount of valuable floor space, and additionally, requires the sorting of
the holding trays into a proper order prior to a second pass through the
system. The sorting process is time consuming and prone to sorting errors.
In many instances, the sorting of the holding trays also has to be
performed manually, which adds to time, cost and labor.
Once the holding trays are properly sorted, they are again fed back through
the system. In doing so, it is now possible to reassign the directions in
the following manner, for example,
Direction #1 1 2 3 4
Direction #2 5 6 7 8
Direction #3 9 10 11 12
Direction #4 13 14 15 16
Now, each direction is a provided in sequenced set of delivery points. That
is, direction 1 has delivery points for 1, 2, 3 and 4. Direction 2 has
delivery points for 5, 6, 7, and 8. Direction 3 has delivery points for 9,
10, 11 and 12. Lastly, direction 4 has delivery points for 13, 14, 15 and
16.
But, it should be understood that the same problem exists. That is, after
each holding tray is filled, it must be removed from the system, placed in
a storage stage, and eventually sorted for future delivery. In the sorting
process, it is necessary to ensure that the holding trays holding the mail
pieces are provided in a proper sequence so as to enable the carrier to
easily traverse his or her route in the most time and cost efficient
manner. But, sorting errors are abound resulting, in many instances, an
improper sequence order of the trays. This, of course, may lead to the
improper delivery of the mail pieces to an incorrect delivery point.
Although this type of system is an improvement over manual sorting and
sequencing, and allows for less delivery errors, there still remain many
shortcomings. These shortcomings include sorting errors, the need for
increased flooring space for storage, increased sorting and sequencing
runs and the like. Also, if there are sorting errors, the carrier may find
it difficult to efficiently traverse the assigned route, with many mail
pieces being improperly delivered or undelivered. Also, there may be
instances when manual intervention is needed, which increases labor costs
and lowers efficiencies throughout the entire system. Thus, it is evident
that much economy and improvement in delivery service could be obtained by
accurately ordering of the mail pieces without the requirements for
sorting of the holding trays and the like.
The present invention is directed to overcoming one or more of the problems
as set forth above.
SUMMARY OF THE INVENTION
In a first aspect of the present invention, a method is provided for
sequencing objects in trays located at tray locations of bin sections. The
method includes assigning a predetermined direction to tray locations,
where each of the tray locations provides space for trays. The
predetermined direction may include a same direction or different
directions for each tray location. The steps of this first aspect of the
invention further include providing an unassigned designation to at least
one tray location which provides tray space for placement of objects such
that the placed objects remain in sequence. The objects are placed into
the trays which correspond to assigned directions of the objects. A
determination is made as to whether there are additional objects requiring
placement corresponding to the same predetermined direction and, if so,
the method assigns the predetermined direction to unassigned tray
locations based on pre-defined rules. The objects are placed in the trays
at the subsequently assigned tray locations. The trays are moved to the
feeder system in a sequential order based on the predetermined direction.
In a second pass utilizing the first aspect of the present invention, the
method includes reassigning the predetermined direction to the tray
locations based on a number of trays required to hold the objects. The
reassigning step ensures that a lower number reassigned direction is in
front of a higher number reassigned direction in an unloading direction.
The objects are placed into the trays of the tray locations corresponding
to the directions associated with the objects. The trays are then
transported to an unloading stage area in a sequential order corresponding
to the reassigned direction.
In a second aspect of the present invention, the method includes providing
a direction to front tray locations based on first pass pre-assignment
rules. The direction may be a same direction or different directions
dependent on an amount of routes required. The method includes a
commencement of a first pass and a second pass. In the first pass:
(i) at least one front tray location is provided with an unassigned
designation. The at least one front tray location provides tray space for
placement of objects;
(ii) the objects are placed into trays corresponding to the direction
associated with the objects;
(iii) the filled trays are moved onto a transporting system only if lower
assigned trays remain unblocked. The moved trays will provide an empty
tray location;
(iv) the empty tray location may be now designated as unassigned;
(v) a determination is then made as to whether there are additional objects
requiring placement which correspond to the direction. If so, the
direction will be assigned to the unassigned tray locations for placement
of the additional objects; and
(vi) the trays will be moved to a feeder system in sequential order of the
assigned direction.
In the second pass of the second aspect of the invention,
(i) the direction will be reassigned to the tray locations based on a
number of trays required to hold the objects in the reassigned direction
and, in aspects, whether there are more than two trays having a same
assigned direction;
(ii) the objects will be placed into the trays at the tray locations
associated with the reassigned directions. Each placed object is related
to one of the reassigned directions of the tray locations in which the
objects are placed; and
(iii) the trays will be transported to an unloading area based on a
sequential order of the reassigned directions.
In still another aspect of the present invention, a method of sequencing
objects in trays located at tray locations of bin sections is provided. In
the steps of this aspect, directions to tray locations are pre-assigned.
Objects are placed in a tray in one of the tray locations such that each
placed object is related to one of the directions of the tray locations in
which the objects are place. The filled trays are moved in sequential
order based on the directions. The tray locations are reassigned the
direction and the objects are placed into the trays at the tray locations
associated with the reassigned directions. The trays are transported to an
unloading area based on a sequential order of the reassigned directions.
In yet another aspect of the present invention, a system for sequencing
objects in trays located at tray locations of bin sections is provided. In
this system a module is provided which assigns a predetermined direction
to tray locations. The predetermined direction includes a same direction
or different directions and each of the tray locations provides space for
trays. A first pass module controls the assignment designation to at least
one tray location of the tray locations. This module also controls
placement of the objects into the trays of the tray locations
corresponding to assigned directions of the objects. The first pass module
also determines whether there are additional objects requiring placement
which correspond to the predetermined direction and, if so, assigns the
predetermined direction to unassigned tray locations based on pre-defined
rules. Thereafter, the first pass module controls the movement of the
trays to a feeder system in sequential order based on the predetermined
direction.
The second pass module of this aspect of the invention controls the
reassignment of the predetermined direction to the tray locations based on
a number of trays required to hold the objects. The reassignment ensures
that a lower number reassigned direction is in front of a higher number
reassigned direction in an unloading direction. The second pass module
then controls placement of the objects into the trays and transportation
of the trays to a loading area in a sequential order corresponding to the
reassigned direction.
In another aspect of the present invention, a system is provided for
sequencing objects in trays located at tray locations of bin sections. The
system includes a mechanism for pre-assigning a direction to tray
locations adapted for placing trays and a mechanism for placing an object
in a tray corresponding to the direction. Additionally, a mechanism is
provided for moving trays with the objects through a transporting system
of the feeder system in sequential order based on predefined rules. A
mechanism is provided for reassigning the direction to the tray locations
based on a number of trays required to hold the objects in the reassigned
direction. A mechanism is also provided for transporting the trays once
objects are placed in the trays having a corresponding direction to an
unloading area based on a sequential order of the reassigned directions.
In another aspect of the present invention a sequencing system includes at
least one feeder having a reading device and a moving mechanism provided
to hold a plurality of holding devices. The system further includes at
least one bin positioned adjacent to the moving mechanism, each bin being
designated with at least one front tray location and at least one rear
tray location capable of being assigned to a direction. A transporting
system is adjacent the front tray location. The transporting system either
transports objects to the at least one feeder and to a delivery point in
sequential order.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, aspects and advantages will be better
understood from the following detailed description of a preferred
embodiment of the invention with reference to the drawings, in which:
FIG. 1 shows an embodiment of the tray sequencing system of the present
invention;
FIG. 2 shows an example of a first pass pre-assignment rule in accordance
with an embodiment of the present invention;
FIG. 3 shows a flow diagram for sequencing flats during a first pass using
an embodiment of the tray sequencing system of FIG. 1;
FIG. 4 shows a flow diagram for sequencing flats during a first pass using
an embodiment of the tray sequencing system;
FIG. 5 is an illustrative example using the flow steps of FIGS. 3 and 4;
FIG. 6 shows a flow diagram for sequencing flats in a delivery order after
completion of the first pass; and
FIG. 7 is an illustrative example using the flow steps of FIG. 6.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
The present invention is directed to a system and method for sequencing
flats and other objects. These flats and objects, hereinafter referred to
as flats, may be mail pieces, magazines, catalogs, bundles or other
defined objects having certain predefined dimensions. The system and
method of the present invention may be used to sequence flats for delivery
by a postal system such as the United States Postal Service, or is also
well adapted to sequencing flats for warehousing or storage. By using the
method and system of the present invention, sorting and excessive movement
of holding trays may be eliminated thus reducing the need for additional
flooring space, as well as eliminating potential sorting errors due to
excess sorting steps. The use of the present invention also reduces the
steps needed to sequence the flats and thus reduces associated costs and
the like.
Embodiments of Flats Sequencing and Method of Use of the Present Invention
FIG. 1 shows an embodiment of the tray sequencing system of the present
invention. The tray sequencing system of the present invention is
generally depicted as reference numeral 10 and includes a plurality of
flat feeders 12a-12d, each having a bar code scanner 14a-14d,
respectively, or other optical reading device. Those of ordinary skill in
the art, though, should recognize that any number of feeders and
respective optical reading devices may be used with the present invention
and that the use of four flat feeders and respective optical reading
devices is provided for illustrative purposes only. Thus, the present
invention is not limited to any number of flat feeders and respective
reading devices.
Still referring to FIG. 1, a carousel 16 is provided to hold a plurality of
carriers 18. The carousel 16, in one embodiment, is a two tiered
continuous looped transport system in which each carrier 18 is designed to
include four pockets, each assigned to a respective flat feeder 12a-12d.
In use, the feeders 12a-12d are designed to deposit flats into the
respective carriers 18 for transport to holding trays 20 positioned at a
respective bin 22. The holding trays may be designed to hold any number of
flats, depending on the application of the present invention. Information
from the flats are read by the bar code scanners or other optical devices
and stored for future use by the system of the present invention. A
control system "C" controls the system and processes of the present
invention. The deposited flats may be transported from the feeders to the
carriers and then into the trays by any well-known or conventional system.
For example, the system may use known robotics, mail handling systems and
like to effectuate the handling of the flats throughout the entire system.
At each bin 22, is a front tray location 22a and rear or back tray location
22b each capable of being assigned to a direction (i.e., a logical
assignment of a set of delivery points selected for sequencing the flats).
In embodiments, the front tray location 22a is located closest to a
conveying system 24 and the back tray location 22b is located farthest
from the conveying system 24. In embodiments, for example, the front tray
location 22a may be on a first side of the carousel 16 closest to the
conveying system 24 and the back tray location 22b may be on the other
side of the carousel 16, farther away from the conveying system 24. Of
course, there may be other configurations following this ordering scheme,
and additionally there may be three or more tray locations for each bin
section, depending on the application of the present invention. The trays
20 are transported to the tray locations via a tray conveying system 26.
The conveying system may carry the trays (i) back to the feeders for a
second pass or (ii) in a sequential delivery order to an unloading area
for future delivery or storage after the second pass is complete.
FIG. 2 shows an example of a first pass pre-assignment rule in accordance
with an embodiment of the present invention. In this illustration, the
pre-assignment rule is associated with the use of the tray sequencing
system 10 of FIG. 1. That is, the first pass pre-assignment rule of FIG. 2
is used with a system having four feeders and includes four partitions. In
addition, the example of FIG. 2 uses 360 bin sections numbered 1 through
360, each bin section having a front tray location and a back tray
location. In the example of FIG. 2, each partition thus has 90 bin
sections (i.e., 360 bins/4 partitions). Also, in the example of FIG. 2, 85
directions are assigned to each of the four partitions thus providing for
340 directions. The directions, in this example, are merely illustrative
of an amount of routes the present invention will sequence for future
delivery. The directions may be assigned in the following manner: 650
delivery points per carrier (any arbitrarily assigned number) are
multiplied by 11 carriers for each partition. This equals 7150, of which
the square root equals approximately 85 directions.
In the pre-assignment rule, directions are assigned to a respective tray
location, with the exception of at least one front tray location being
unassigned. In this example, all back tray locations are unassigned. The
use of the unassigned tray location(s) will become apparent in view of the
flow diagrams and further examples discussed below.
In the example of FIG. 2, the first pass pre-assignment rule assigns 85
directions to each partition. In the 1.sup.st partition, directions 1-85
are pre-assigned to front tray locations of bin sections 6-90, leaving bin
sections 1-5 unassigned. In the 2.sup.nd partition, directions 86-170 are
pre-assigned to front tray locations of bin sections 91-175, leaving bin
sections 176-180 unassigned. In the 3.sup.rd partition, directions 171-255
are pre-assigned to front tray locations of bin sections 186-270, leaving
bin sections 181-185 unassigned. In the 4.sup.th partition, directions
259-340 are pre-assigned to front tray locations of bin sections 270-355,
leaving bin sections 356-360 unassigned. It should be recognized that due
to the configuration of the looped carousel, the bin sections of the
1.sup.st and 3.sup.rd partitions will be numbered in increasing sequential
order leading away from the feeders. In contrast, the bin sections of the
2.sup.nd and 4.sup.th partitions will be numbered in increasing sequential
order as they are located closer to the feeders.
Those of ordinary skill in the art should recognize that more or less than
four partitions might be used with more or less than 360 bin sections.
Additionally, the numbering of the bin sections may also vary depending on
the configuration of the looped carousal, the number of delivery points,
etc. By way of example, two partitions each having 50 bin sections and 45
directions may be implemented using the first pre-assignment rule of the
present invention. In this scenario,
(i) directions 1-45 may be pre-assigned to the front tray locations of bin
sections 6-50, with front tray locations of bin sections 1-5 being
unassigned, and
(ii) directions 46-90 may be pre-assigned to front tray locations of bin
sections 56-100, with front tray locations of bin sections 51-55 being
unassigned.
As another example, 48 directions may be assigned to the 50 bin sections of
each partition. In this example,
(i) directions 1-48 may be pre-assigned to front tray locations of bin
sections 3-50, with bins 1 and 2 being unassigned, and
(ii) directions 49-98 may be pre-assigned to front tray locations of bin
sections 58-100 with bin sections 51 and 52 being unassigned.
Again, in these examples, all back tray locations are unassigned.
FIG. 3 shows a flow diagram for sequencing flats during a first pass using
an embodiment of the tray sequencing system of FIG. 1. In this flow, two
trays are assigned to each bin section, and the initial bin allocation
using the pre-assignment rule of FIG. 2 is provided. It should be noted
that the flow diagram of FIG. 3 (and FIGS. 4 and 6) may represent a
high-level block diagram of the present invention. A computer software
program or hardwired circuit can be used to implement the steps of the
present invention. In the case of software, the program can be stored on
media such as, for example, magnetic media (e.g., diskette, tape, or fixed
disc) or optical media such as a CD-ROM. Additionally, the software can be
supplied via the Internet or some other type of network. A workstation or
personal computer that typically runs the software includes a plurality of
input/output devices and a system unit that includes both hardware and
software necessary to provide the tools to execute the steps of the
present invention.
Referring now more specifically to FIG. 3, in step 300, the process begins.
At step 302, a determination is made as to whether a front tray associated
with a pre-assigned direction is filled. If not, at step 304 the system
will continue to fill the tray for that direction. If the front tray is
filled, the process continues to step 306, at which time a determination
is made as to whether the conveying system is empty in front of the filled
tray. If filled (not empty), at step 308, the process waits until the
first pass sequence ends. If the conveying system is empty in front of the
filled tray, a determination is made at step 310 as to whether a lower
direction tray will be blocked by moving the tray onto the conveying
system. If not, the tray is moved onto the conveying system at step 312.
If there is a blockage, the process returns to step 308. At step 314, the
back tray is moved to the front tray location at an earliest convenience
in order to ensure that an upcoming flat for that direction may still be
loaded into the tray prior to such movement. In embodiments, this would be
considered a "wait" time. And, at step 316 an empty tray is placed at the
back tray location. At step 318, the tray is moved as far forward as
possible on the conveying system without blocking a lower direction or
pre-assignment.
Now, FIG. 4 shows further steps for assigning tray locations when a tray is
filled for a particular direction and overflow flats having the same
direction must be dropped at a tray location. At step 400, the process
starts to scan in a sweep direction starting with the pre-assigned
location (i.e., the location of the filled tray for that direction). At
step 402, a determination is made as to whether the pre-assigned tray
location is empty. If the tray location is empty, the process then assigns
that tray location the same direction at step 404. If not, at step 406 the
process begins to scan in the sweep direction starting from the filled
tray location for that direction. At step 408, a determination is made as
to whether the front tray location is free and all trays on the conveying
system toward the sweep direction have a lower or equal direction. If yes,
then the process assigns the direction to that front tray location at step
410. If not, then a determination is made as to whether the back tray
location is free and the front tray location has a lower or equal
direction (step 412). If yes, at step 414 the process assigns the
direction to that back tray location.
FIG. 5 shows an example implementing the steps of FIGS. 3 and 4. In FIG. 5,
an example of two flats per tray is illustrated with the use of four
feeders and one partition. In FIG. 5, the example also includes directions
1-20 with the use of 23 bin sections. Initially, front tray locations of
bin sections 3-23 are assigned directions 1-20 (direction 19 is assigned
to bin sections 21 and 22), with the remaining tray locations being
unassigned. The unassigned bin sections include, amongst others, front
tray locations of bin sections 1 and 2. It is well understood that the
example of FIG. 5 is merely one illustrative example implementing the flow
steps of FIGS. 3 and 4, and thus the present invention should not be
limited in any manner to this specific example. Instead, the present
invention contemplates many scenarios using the steps discussed herein
such as the use of more or less sequences, more or less bin sections or
the like.
Referring to sequence 1, front trays of directions 7 and 10 are filled
(i.e., sequence 1 on the left side of the illustration shows two flats for
direction 7 and 10) and moved onto the conveying system. The front tray
locations for directions 7 and 10 are associated with bin sections 9 and
12, respectively. This is possible because the following holds true:
1. a front tray associated with a pre-assigned direction is filled (step
302);
2. the conveying system is empty in front of the tray (step 306); and
3. moving the tray onto the conveying system (step 312) will not block a
lower direction tray (step 310).
Still referring specifically to direction 10, in sequence 2, the front tray
of bin section 12 for direction 10 is filled. Referring to FIG. 4, this
tray is filled, after scanning in the sweep direction (step 400), because
it was determined that:
1. the pre-assigned tray location 10 was empty;
2. a new tray was moved in its place; and
3. the new tray was ready to be filled by flats having a direction of 10
(step 402).
In sequence 3, there are no further 10 directions. In this sequence, a
discussion of the 11 and 12 directions will be illustrated using the steps
of FIGS. 3 and 4. In this scenario, front trays assigned to direction 11
and direction 12 are both placed on the conveying system in accordance
with the steps of FIG. 3. Also the front tray locations for directions 11
and 12 are filled in accordance with steps 400 and 402. (See, sequence 1
and 2.) Now, for direction 12, once the pre-assigned front tray of bin
section 14 is filled, then the back tray of bin sections 14 and 13, in
order, will be filled in accordance with steps 412 and 414. Similarly, for
direction 11, once the pre-assigned front tray of bin section 13 is
filled, and the back tray of bin 13 is partially filled with flats for
direction 12, then the back tray of bin section 12 will be filled with
flats for direction 11.
In sequence 4, the need for unassigned tray locations becomes apparent.
Specifically, as the process moves through the steps of FIGS. 3 and 4, the
lower directions may be assigned to the unassigned tray locations. This
happens due to higher directions being assigned to tray locations in lower
numbered bin sections, for example, with reference to direction 11. To
illustrate this subtlety, direction 1, in sequence 4, is assigned to all
tray locations and the conveying system position of bin section 3 and the
front tray location of bin section 2, a previously unassigned location.
This is due to direction 2 being assigned to bin section 4 and the
requirement that four trays are needed for direction 1. Thus, the
unassigned bin sections may become important, in certain embodiments, of
the present invention.
It is also seen in this example, that previously assigned tray locations
may become unassigned locations after filled trays are moved onto he
transporting system (i.e., sequence 3, front tray locations of bin
sections 9-11). In this specific situation, the previously assigned
directions for 7, 8 and 9, in sequence 3 are turned into unassigned
locations when the trays for the directions are moved onto the conveying
system. Thereafter, using the steps of the present invention, these
unassigned tray locations of bin sections are then reassigned directions
12, 13, 11, respectively, for sequence 4. In this manner, all lower
directions remain unblocked by a higher direction.
Once all of the flats are properly loaded into the assigned trays, the
trays are moved in sequential order to the feeder. That is, starting with
the lowest to the highest assigned directions, all of the trays are placed
on the conveying system and transported to the feeder for a second pass.
By way of example, all of the trays assigned with a 1.sup.st direction are
placed on the conveying system prior all of the trays assigned with a
2.sup.nd direction. This procedure is followed until all of the trays are
placed on the conveyor, i.e., the trays assigned with directions 1-20. In
this manner, the sequentially ordered trays will now reach the feeders in
an order according to a set of delivery points, for a second and final
pass.
FIG. 6 shows a flow diagram for sequencing flats in a delivery order using
a second pass. In this example, two trays are allocated to each bin
section and the bin output can selectively output to one of the two trays.
Additionally, the front tray is physically in front of the back tray such
that the back tray cannot move to the conveying system through the front
tray. Additionally, the pre-assigned tray locations are based on recorded
data used in the first pass.
At step 600, the process starts scanning the first available tray location
in a bin section. In this step, the scanning is performed away from the
sweep order (away from the unloading area). At step 602, a determination
is made as to whether there are one or two trays in the same direction. If
yes, then the process proceeds to step 604. At step 604, the direction
will be assigned to the next available tray location, always filling the
front tray location first. If there are more than two trays for a
direction, at step 606, the bin section is preset to the next bin section
where all tray locations are free. At step 608, a direction is assigned to
the bin section. In this step, the process assigns a direction to all
conveying system positions between and including the preset bin location
and the preset bin location-(number of trays per direction-X) and assigns
all tray locations to the preset bin location-(number of trays per
direction-X). In the case that the preset bin location-(number of trays
per direction-X)<0, at step 610, all left over directions are assigned
to any back tray location available in that partition. It should be
understood that X could be any number that equals the number of tray
locations and conveying system location for each bin section. For example,
using the embodiment of FIG. 1, X=3.
FIG. 7 is an example implementing the flow steps of FIG. 6. The example of
FIG. 7 is merely one illustrative example implementing the flow steps of
FIG. 6, and thus the present invention should not be limited in any manner
to this specific example. Instead, the present invention contemplates many
scenarios using the steps discussed herein such as more or less sequences
and more or less bin sections. In FIG. 7, two sequences are provided, with
20 directions. In this example, much like that discussed in the example of
FIG. 5, each tray is capable of holding two flats. In this example, 22 bin
sections are used and each bin section has two tray locations and one
conveying system location (X=3).
Implementing the steps of FIG. 6, the following is illustrative of the use
of several different directions. First, the pre-assigned tray locations
are based on the recorded data used in the first pass. Then, it is
determined that there are eight flats for direction 1, translating into
four trays. For this example, a simplifying assumption is made that two
flats equal a full tray, but in practice, many flats may make a full tray.
Using the steps of FIG. 6, it is determined that there are more than two
trays in direction 1 (step 602). Using step 606, bin section 22 is preset
since this bin section has both tray locations free. Then, a direction is
assigned to the conveying system and tray location (corresponding to a bin
section) using the following calculations of step 608:
1. The conveying system location is assigned a direction based on all
conveyor positions between and including the preset bin section and the
preset bin section-(number of trays per direction-3). In this example, the
preset bin section is 22 and the preset bin section-(number of trays per
direction-3) is 21. Thus, the system of the present invention will assign
a direction to all conveying system locations associated with bin sections
21 and 22. Two trays will then be loaded and transported onto the
conveying system at bin sections 21 and 22.
2. The tray locations will be assigned based on the preset bin
location-(number of trays per direction-3). In this example, the tray
locations associated with bin sections 22 will be assigned direction 1
(i.e., preset bin location of 22-(4 trays-3)). Two trays will then be
loaded for the front and back tray locations at bin section 21.
By way of further example, direction 2 has four flats, which translates
into the need for two trays. Using the steps of FIG. 6, it is first
determined that there are two trays in direction 2 (step 602).
Implementing step 604, it is determined that there are two free trays in
bin section 22. Then, a direction 2 is assigned to the two free trays in
the front tray location and the back tray location of bin section 22. This
same process may be used for directions 3 through 8, 10, 15 and 17-20.
In an example using direction 9, there are seven flats requiring four
trays. Using step 602, it is determined that there are more than two trays
needed for direction 9. Thus, implementing step 606, bin section 15 is
preset since this bin section has both tray locations free, noting that
directions 1-8 occupy, partially or fully, bin sections 16-22. Then, using
the formula of step 608, a direction is assigned to the conveying system
and tray location (corresponding to a bin section) using the following
calculations:
1. The conveying system location is assigned based on all conveyor
positions between and including the preset bin section and the preset bin
section-(number of trays per direction-3). In this example, the preset bin
section is 15 and the preset bin section-(number of trays per direction-3)
is 14. Thus, the system of the present invention will assign direction 9
to all conveying system locations associated with bin sections 14 and 15.
Two trays will then be loaded and transported onto the conveying system at
bin sections 14 and 15.
2. The tray locations will be assigned based on the preset bin
location-(number of trays per direction-3). In this example, the tray
locations associated with bin section 14 will be assigned direction 9
(i.e., preset bin location of 15-(4 trays-3)). This same procedure will be
used for the remaining directions requiring three or more trays (i.e.,
directions 11-14 and 16).
Once all of the trays are properly filled, they will be incrementally and
sequentially placed on the conveying system (as discussed with reference
to FIG. 5), but now transported to the unloading area for delivery or
storage. In this manner, there is no need for sorting of the trays, thus
requiring less floor space and less time and expense.
While the invention has been described in terms of preferred embodiments,
those skilled in the art will recognize that the invention can be
practiced with modification within the spirit and scope of the appended
claims.
*
