METHOD FOR THE MANAGEMENT, IN FLOW MODE, A BUFFER STORAGE AND LOAD SEQUENCING SYSTEM, AND CORRESPONDING MANAGEMENT UNIT

• US 20200130950A1
• Filed: 10/29/2019
• Published: 04/30/2020
• Est. Priority Date: 10/30/2018
• Status: Active Grant

• Current Assignee: Savoye
• Original Assignee: Savoye
• Inventors: Pietrowicz, Stephane, Collin, Jean-Michel, Vacher, Blandine
• Granted Patent: US 11,319,162 B2
• Time in Patent Office: Days
• CPC Class Codes: B65G 43/10 Sequence control of conveyors operating in combination
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management

Abstract

A method for managing a buffer storage and load sequencing system. The system receives non-sequenced loads and provides at least one sequence of loads, and includes a buffer storage unit having entrance levels, at least one recirculation level, an entrance elevator facing entrances and an exit elevator facing exits of the levels. A management unit iteratively manages the entrance elevator. At each iteration the entrance elevator: has a “waiting for recirculation” status for a load to be recirculated in the system; holds this elevator until the load to be recirculated has been transferred to the recirculation level, else selects a load at exit from an entrance conveyor or at exit from the recirculation level; if the selection of the entrance level is completed, generates a task, for the entrance elevator, of transferring the selected load to the selected level; if not assigns this load the “awaiting recirculation” status.

Claims

1. A method comprising:

managing, by a managing unit, a buffer storage and load sequencing system, the system being configured to receive non-sequenced loads coming from at least one external unit, via at least one entrance conveyor, and to provide at least one sequence of loads in a given sequential order to at least one preparing station, through at least one exit conveyor, the system comprising;

a buffer storage unit comprising N entrance levels and at least one recirculation level which are vertically superimposed, each having a single entrance and a single exit and each comprising a “

first-in-first-out”

type conveyor in a first sense for the entrance levels and in a second sense opposite the first sense for the at least one recirculation level, with N≥

2, a load present on the at least one recirculation level being called a load in recirculation; and

an entrance elevator and an exit elevator, of the reciprocating and discontinuous type, respectively positioned so as to be facing entrances and facing exits of the N entrance levels and of the at least one recirculation level;

wherein the managing comprises the management unit carrying out an iterative management of the entrance elevator comprising, at each iteration, the following acts;

if the entrance elevator is assigned a “

waiting for recirculation”

status, signifying that there exists at least one load to be recirculated in the system, the entrance elevator is put on hold until said at least one load to be recirculated has been transferred to the entrance of the at least one recirculation level;

if the entrance elevator is not assigned said “

waiting for recirculation”

status;

detecting a first load at an exit of the entrance conveyor and a second load at the exit of the at least one recirculation level;

selecting a load with the following rules;

selecting the first load if there is no second load present or vice versa;

if the first and second loads are present, selecting either routinely the second load or the load having the smallest sequential order number;

selecting a destination level from among the entrance levels in complying with a rule according to which loads present on a same entrance level, except for loads to be recirculated if any, are sequenced in a rising order of sequential order numbers;

if the selection of a destination level is completed, generating a task, for the entrance elevator, of transferring the selected load to the entrance of the selected destination level;

if not;

assigning, to the entrance elevator, said “

waiting for recirculation”

status; and

selecting a level of loads to be recirculated from among the entrance levels, without generating a task, for the entrance level, of transferring the selected load to the entrance of the selected level of loads to be recirculated, and assigning each load of the level of loads to be recirculated a status of a load to be recirculated signifying that said load must be transferred by the exit elevator to the entrance of the at least one recirculation level.

2. The method according to claim 1, wherein the act of selecting a destination level comprises:

assigning a grade to each of the entrance levels with a set of grading rules; and

selecting the entrance level having the highest grade;

and wherein the set of grading rules comprises the following acts for assigning a grade to a given entrance level;

resetting the grade at zero;

if the given entrance level is saturated, decrementing the grade by a value C0;

if the given entrance level is vacant, incrementing the grade by a value C1;

if the sequential order number of the last load entered in the given entrance level is smaller than or equal to the sequential order number of the selected load, incrementing the grade by a value C2;

with;

C1<

C2<

C0.

3. The method according to claim 2, wherein:

C2=C3−

(NumCharge−

NumDerCharge)

with NumDerCharge being the sequential order number of the last load placed on the given entrance level and NumCharge being the sequential order number of the selected load and with C1<

C2<

C0

4. The method according to claim 1, wherein if the selection of a destination level is complete and if the following conditions are verified:

the selected destination level is vacant;

the sequential order number of the selected load is strictly greater than the sequential order number of the load in (N.Y)^th place in a list of loads awaited at exit with Y being the load capacity of each entrance level; and

either the at least one recirculation level is vacant or the last load placed on the at least one recirculation level has a sequential order number smaller than the sequential order number of the selected load;

then the selected destination level takes the status of a level of loads to be recirculated and the selected load takes the status of a load to be recirculated in order to be transferred to the entrance of the at least one recirculation level by the exit elevator.

5. The method according to claim 1, the buffer storage unit further comprising a “

fast track”

level vertically superimposed with the entrance levels and the at least one recirculation level, having a single entrance and a single exit, and comprising a “

first-in-first-out”

type conveyor according to the first sense,

wherein, if one of the following conditions is met, the act of selecting a destination level comprises a selection of the “

fast track”

level;

the sequential order number of the selected load is that of the next sequential number of the lists of loads awaited at exit;

the sequential order number of the selected load is the one directly awaited after the sequential order number of the last load placed on the “

fast track”

level.

6. The method according to claim 1, wherein selecting a level of loads to be recirculated comprises:

for each of the entrance levels, identifying the sequential order number of the load closest to the exit elevator; and

selecting, as a level of loads to be recirculated, the entrance level for which the identified sequential order number is the highest.

7. The method according to claim 1, wherein, if the selection of a destination level is not completed, the iterative management of the entrance elevator comprises a test of the following two conditions:

the at least one exit conveyor is saturated; and

an exit elevator picking position is occupied by a load possessing the next sequential order number in the list of loads awaited at exit;

and wherein the act of selecting a level of loads to be recirculated is not carried out if the two conditions are verified, and if not it is carried out.

8. The method according to claim 1, wherein, if the selection of a destination level is not completed, the iterative management of the entrance elevator comprises a test of the following additional condition:

a predetermined maximum number of level(s) to be recirculated is attained;

and the act of selecting a level of loads to be recirculated is not carried out if said additional condition is verified, and if not it is carried out.

9. The method according to claim 8, wherein the predetermined maximum number of level(s) of loads to be recirculated is equal to one.

10. (canceled)

11. A non-transitory computer-readable storage medium storing a computer program product comprising program code instructions, which when executed by a processor of a management unit configure the management unit to manage a buffer storage and load sequencing system, the system being configured to receive non-sequenced loads coming from at least one external unit, via at least one entrance conveyor, and to provide at least one sequence of loads in a given sequential order to at least one preparing station, through at least one exit conveyor, the system comprising:

a buffer storage unit comprising N entrance levels and at least one recirculation level which are vertically superimposed, each having a single entrance and a single exit and each comprising a “

first-in-first-out”

type conveyor in a first sense for the entrance levels and in a second sense opposite the first sense for the at least one recirculation level, with N≥

2, a load present on the at least one recirculation level being called a load in recirculation; and

an entrance elevator and an exit elevator, of the reciprocating and discontinuous type, respectively positioned so as to be facing entrances and facing exits of the N entrance levels and of the at least one recirculation level;

wherein the program code instructions configure the management unit to carry out an iterative management of the entrance elevator comprising, at each iteration, the following acts;

if the entrance elevator is assigned a “

waiting for recirculation”

status, signifying that there exists at least one load to be recirculated in the system, the entrance elevator is put on hold until said at least one load to be recirculated has been transferred to the entrance of the at least one recirculation level;

if the entrance elevator is not assigned said “

waiting for recirculation”

status;

detecting a first load at an exit of the entrance conveyor and a second load at the exit of the at least one recirculation level;

selecting a load with the following rules;

selecting the first load if there is no second load present or vice versa;

if the first and second loads are present, selecting either routinely the second load or the load having the smallest sequential order number;

selecting a destination level from among the entrance levels in complying with a rule according to which loads present on a same entrance level, except for loads to be recirculated if any, are sequenced in a rising order of sequential order numbers;

if the selection of a destination level is completed, generating a task, for the entrance elevator, of transferring the selected load to the entrance of the selected destination level;

if not;

assigning, to the entrance elevator, said “

waiting for recirculation”

status; and

selecting a level of loads to be recirculated from among the entrance levels, without generating a task, for the entrance level, of transferring the selected load to the entrance of the selected level of loads to be recirculated, and assigning each load of the level of loads to be recirculated a status of a load to be recirculated signifying that said load must be transferred by the exit elevator to the entrance of the at least one recirculation level.

12. A management unit comprising:

a processor; and

a non-transitory computer-readable storage medium comprising program code instructions stored thereon, which when executed by the processor configure the management unit to manage a buffer storage and load sequencing system, the system being configured to receive non-sequenced loads coming from at least one external unit, via at least one entrance conveyor, and to provide at least one sequence of loads in a given sequential order to at least one preparing station, through at least one exit conveyor, the system comprising;

a buffer storage unit comprising N entrance levels and at least one recirculation level which are vertically superimposed, each having a single entrance and a single exit and each comprising a “

first-in-first-out”

type conveyor in a first sense for the entrance levels and in a second sense opposite the first sense for the at least one recirculation level, with N≥

2, a load present on the at least one recirculation level being called a load in recirculation; and

an entrance elevator and an exit elevator, of the reciprocating and discontinuous type, respectively positioned so as to be facing entrances and facing exits of the N entrance levels and of the at least one recirculation level;

wherein the program code instructions configure the management unit to carry out an iterative management of the entrance elevator comprising, at each iteration, the following acts;

if the entrance elevator is assigned a “

waiting for recirculation”

status, signifying that there exists at least one load to be recirculated in the system, the entrance elevator is put on hold until said at least one load to be recirculated has been transferred to the entrance of the at least one recirculation level;

if the entrance elevator is not assigned said “

waiting for recirculation”

status;

detecting a first load at an exit of the entrance conveyor and a second load at the exit of the at least one recirculation level;

selecting a load with the following rules;

selecting the first load if there is no second load present or vice versa;

if the first and second loads are present, selecting either routinely the second load or the load having the smallest sequential order number;

selecting a destination level from among the entrance levels in complying with a rule according to which loads present on a same entrance level, except for loads to be recirculated if any, are sequenced in a rising order of sequential order numbers;

if the selection of a destination level is completed, generating a task, for the entrance elevator, of transferring the selected load to the entrance of the selected destination level;

if not;

assigning, to the entrance elevator, said “

waiting for recirculation”

status; and

selecting a level of loads to be recirculated from among the entrance levels, without generating a task, for the entrance level, of transferring the selected load to the entrance of the selected level of loads to be recirculated, and assigning each load of the level of loads to be recirculated a status of a load to be recirculated signifying that said load must be transferred by the exit elevator to the entrance of the at least one recirculation level.