Method and system for transporting items

Abstract

The present invention relates to a method for transporting items (P1, P2, P3, P4, P5) in an intralogistics system (1) using autonomous mobile robots (A, B, C), each capable of transporting one item (P1, P2, P3, P4, P5) within a transport circuit (2) of said system, the method comprising a step of forming a platoon (C1, C2) comprising at least two mobile robots (A, B, C) traveling at the same speed along at least one section of the circuit (2). The invention also relates to a system for carrying out this method, as well as to an installation for sorting articles comprising such a system.

Description

[Technical Field]

[0001] The present invention relates to the field of intralogistics and to a system and method for transporting objects using autonomous mobile robots (or automated guided vehicles), each capable of moving at least one item.

[0002] Such a transport system can be used, for example, in a sorting facility or an automated storage system. [Background technology]

[0003] Many applications, such as those mentioned above, use autonomous mobile robots (AMRs) or automatically guided vehicles (AGVs) to transport objects to be sorted or stored within intralogistics facilities. The simultaneous circulation of a large number of such robots / vehicles within a circuit creates a risk of collisions between the robots / vehicles, meaning that the movement of the robots / vehicles must be managed with this factor in mind. Generally speaking, the risk of collisions is limited by using circuits without intersections or by implementing priority rules that govern the order of AMR / AGV passage at intersections. While these rules may be satisfactory in certain cases where the work speed is low, they are generally insufficient when the task to be performed requires a high work speed, either to sort items, store them, or retrieve them from inventory to prepare an order.

[0004] Furthermore, known systems only solve certain situations by slowing down. For example, when two robots / vehicles follow each other in the same lane, a slight deviation of the first robot causes the following robot to slow down or stop to avoid a collision. Such repeated slowing down and / or stopping inevitably reduces the working speed of the robots / vehicles and therefore the entire system.

[0005] The aim of the present invention is to propose a new solution for increasing the working speed of AMR / AGVs on intralogistics circuits while limiting the risk of collisions. Summary of the Invention

[0006] To this end, the present invention relates to a method for transporting items in an intralogistics system using autonomous mobile robots or automated guided vehicles, each capable of transporting one item within a transport circuit of said system, the method comprising the step of forming a platoon comprising at least two robots / vehicles traveling at the same speed along at least one section of said transport circuit.

[0007] Platooning allows the average distance between autonomous mobile robots or automated guided vehicles to be reduced, thereby increasing throughput.

[0008] A platoon is a set of autonomous mobile robots (or AGVs) moving at substantially the same speed along a single track or along closely spaced parallel tracks (according to a defined separation distance).

[0009] "Substantially the same speed" means that AMR / AGVs in the same convoy may, for example, have the same speed on straight sections of a circuit and have identical speed profiles on curves for changing direction, and their speeds remain very close along the route.

[0010] Advantageously, the formation process is carried out in a so-called introduction section and includes defining a grid of theoretical positions each of which can be occupied by an autonomous mobile robot, the grid including a plurality of parallel tracks and a plurality of successive parallel rows that intersect the tracks and form a non-zero angle with the tracks, the formation including two or more robots in different rows positioned such that two robots in successive rows on the same track are separated by a predetermined minimum distance.

[0011] Using this grid of theoretical positions, different possible arrangements of AMRs (or AGVs) can be generated to form a platoon. Such positions can include a single track robot or a platoon with robots from different tracks. The platoon is formed within the lead-in section of the circuit. Robots arriving at this section, which may have different speeds, are organized in this area by adapting their speed and / or changing their position to place them on one or more tracks and with rows corresponding to the rows of the theoretical grid. Once the platoon is formed, the mobile robots (or AGVs) move together at substantially the same speed. Optionally, it may be possible to select the best configuration by comparing possible configurations. This configuration can be selected to enable smoother movement of the AMRs.

[0012] The minimum distance avoids collisions between mobile robots on the same trajectory along the route.

[0013] Advantageously, the formation step includes a sub-step in which two theoretical grid positions having the same row and belonging to two adjacent tracks are offset in the longitudinal direction of the lead-in section by a distance equal to the (lateral) distance between said two adjacent tracks.

[0014] Advantageously, the rows in the lead-in section form angles of +45° or −45° with the trajectory, corresponding to a positive or negative orientation of the formation, respectively.

[0015] Advantageously, a distribution section connected to the introduction section is added to the transport circuit, said distribution section having one or more parallel robot entrance trajectories intersecting several parallel robot exit trajectories, said exit trajectories forming a non-zero deviation angle with the robot entrance trajectories, and the method further comprises the step of moving the robots in said formation between said entrance trajectories and said exit trajectories at substantially the same speed.

[0016] Advantageously, the deviation angle defines a positive or negative orientation of the distribution section: if the angle is negative (positive), the distribution section is considered to be negative (positive) oriented.

[0017] The number of entrance trajectories may be equal to the number of trajectories in the introduction region.

[0018] A distribution section is formed by one or more entrance tracks intersecting with an exit track, so that at each intersection, the AMR / AGV can change direction and therefore all exits are accessible from any entrance. This allows the best route to be selected and, consequently, throughput to be improved by expanding the possible routes.

[0019] Additionally, when the distribution section is traversed by a platoon with the correct configuration (orientation and distance between vehicles), there are no collisions between vehicles, regardless of the exit chosen. In particular, this is made possible by maintaining a minimum distance between robots on the same track and by longitudinally offsetting ranges belonging to parallel tracks.

[0020] Advantageously, the robots can be controlled to group together in a formation that forms a platoon at the exit of the distribution section.

[0021] Advantageously, additional distribution sections are added to the circuit, having one or more parallel second robot entrance trajectories intersecting one or more parallel second robot exit trajectories, said second exit trajectories forming with the second robot entrance trajectories a deviation angle that is non-zero and, optionally, opposite in orientation to the angle of the distribution section, and the method further comprises moving the platoon at substantially the same speed between at least one of said second entrance trajectories and said second exit trajectories, which increases the number of possible routes, avoids collisions, and makes AMR / AGV movement more fluid.

[0022] Advantageously, the deviation angle defines a positive or negative orientation of the distribution section: if the angle is negative (positive), the distribution section is considered to be negative (positive).

[0023] This expands the number of possibilities for an AMR / AGV to change direction without risking a collision.

[0024] Advantageously, the distribution section and / or the further distribution section may be unidirectional to reduce the risk of collisions.

[0025] According to example embodiments, the deviation angle of the distribution section and / or the additional distribution section is -90° or 90°.

[0026] When two distribution sections are arranged in series, the orientation of the second distribution section can depend on the orientation of the first distribution section, for example, if the distribution section is positively oriented (the deviation angle is positive), the second section is negatively oriented.

[0027] The orientation of the formation in the induction section may depend on the orientation of the distribution section, for example, if the distribution section is positively oriented, then the formation will also be positively oriented.

[0028] Advantageously, the method may include a step for changing the orientation of the formation by accelerating and / or decelerating the autonomous mobile robots in a reorientation area provided between two consecutive distribution sections.

[0029] According to one embodiment, the distance between two tracks is a = L + d, where L is the length of the robot. In this advantageous embodiment, if the parallel connecting tracks between two consecutive distribution sections are separated by L + d (where L is the length of the vehicle and d is the distance between the two vehicles in the platoon), there is no need to change the orientation of the platoon to avoid a collision.

[0030] In some exemplary embodiments, the formation includes at least two autonomous mobile robots on the same trajectory.

[0031] According to an exemplary embodiment, when a first robot and a following second robot in the same formation on the same entrance trajectory take a first exit trajectory, the second robot takes a second exit trajectory that is located before the first exit trajectory.

[0032] This avoids collisions between robots / vehicles on the same track and in the same formation.

[0033] For example, if a first robot in a first row of a formation and a second robot in a subsequent row are intended to arrive via two parallel entrance trajectories and use the same exit trajectory, the first robot will arrive via the first entrance trajectory and the second robot will then arrive via the second entrance trajectory that is further away from the exit end of the exit trajectory.

[0034] This prevents collisions between successive parallel robots / vehicles in the same platoon.

[0035] Advantageously, a formation is separated from the preceding formation by a predetermined safety distance D. This avoids collisions between mobile robots of two successive formations within the distribution section.

[0036] The invention also relates to a computer program comprising instructions for carrying out the steps of the method described above.

[0037] The invention also relates to a computer readable medium containing the above-mentioned computer program.

[0038] The present invention also relates to an intralogistics transport system, the system comprising: a plurality of autonomous mobile robots, each capable of transporting one object; a ground transport circuit along which the mobile robot can circulate; - the computer program as described above.

[0039] The system is configured to perform the method described above.

[0040] The invention further relates to an article sorting installation comprising a sorting area and a transport system as described above.

[0041] The invention also relates to an automated article storage installation comprising an article storage area having a plurality of storage levels and lifting and lowering means connecting said levels, said installation further comprising a transport system as described above. [Brief explanation of the drawings]

[0042] Further characteristics and advantages of the invention will become apparent from the following description with reference to the accompanying drawings, given as non-limiting examples, in which: [Figure 1] 1 shows a schematic representation of a transport circuit in which robots form a formation. [Figure 2] 1 shows a schematic representation of an introductory section. [Figure 3] 1 shows an example of a distribution section connected to an introduction section. [Figure 4] Two consecutive distribution sections are shown. [Figure 5] The reorientation region is shown. [Figure 6] An example of a sorting installation for carrying out the method according to the invention is shown below: In the following description, elements having the same structure or similar function are referred to by the same reference signs. DETAILED DESCRIPTION OF THE INVENTION

[0043] 1 is a partial schematic diagram of an intralogistics transport system 1. System 1 includes a partially shown transport circuit 2 and a set of autonomous mobile robots (AMRs) or AGVs referenced A1, B1, C1, A2, and B2. For simplicity, the following description will refer only to AMRs, but it should be noted that these may also be AGVs or other similar transport means, sometimes referred to in the intralogistics field as shuttles or carts.

[0044] The system also includes control means, not shown. Such means may include a central control means that communicates with local control means located within each AMR. The control means includes one or more computer control programs.

[0045] Circuit 2 includes, for example, two parallel tracks as shown in Fig. 1. Robots A1, B1, and C1 circulating successively on the same track form a first formation C1, where robots A1, B1, and C1 circulate at the same speed and each robot is separated from the next robot by a safety distance d, which is determined so as to avoid collisions between each robot and the next robot in the same formation traveling on the same track.

[0046] AMRs A' and B' travel at the same speed on two parallel tracks to form a second platoon C2, with C1 and C2 separated by a safety distance D determined to avoid collisions between the AMRs of C1 and C2 in the distribution section described below.

[0047] The minimum number of AMRs required to form a formation is two and is determined by applying formation principles.

[0048] In FIG. 1, these AMRs transport items P1, P2, P3, P4, and P5; however, this is not necessary as the AMRs can form a convoy without being loaded, for example, after depositing the items in a warehouse.

[0049] 2 shows a schematic diagram of an example of a lead-in section according to the present invention. Such a section is part of a transport circuit 20 in which at least one convoy is formed. A transport circuit may have one or more lead-in sections.

[0050] As shown in Figure 2, the lead-in section can include one or more tracks T1, T2, T3. In this example, there are three tracks, but the number can vary.

[0051] To create the platoon in the introductory section, a grid of theoretical positions is defined, shown by the dotted lines in Figure 2. The grid includes tracks T1, T2, T3 of the circuit 20 and several parallel rows R1, R2, R3 that intersect with the tracks T1, T2, T3. Each intersection indicates a theoretical position that an AMR / AGV can theoretically occupy. The minimum number of rows in the platoon is two.

[0052] To define a formation, each row R1, R2, R3 is occupied only once, regardless of orbit. Thus, it is possible to have a formation with robots on the same orbit, such as C1 in Figure 1, and it is also possible to have a multi-orbit formation, such as C2 in Figures 2 and 1.

[0053] Advantageously, every two theoretical positions on the same orbit are separated by a predetermined safety distance d.

[0054] As a result, two consecutive robots in the same formation traveling on the same trajectory can also be separated by the same distance.

[0055] Additionally, two theoretical positions, e.g., R1, in the same row located on two adjacent orbits, e.g., T1, T2, can be advantageously offset by a distance a equal to the distance between T1 and T2.

[0056] Furthermore, the position offset and the intersection of the column and the track form a positive or negative angle, e.g., +45° or −45°. For example, in FIG. 2, the orientation is negative. As a result, the column formed by AMRs A3, B3, and C3 is negatively oriented.

[0057] FIG. 3 shows an example of a transport system 10 having the same entrance section Si as shown in FIG. 2. The system 10 further includes a distribution section Sd1. In this example, section Sd1 is formed by three AMR entrance trajectories E11, E12, and E13, which are extensions of the entrance section trajectories T1, T2, and T3. It also includes exit trajectories S11, S12, and S13 that intersect with the entrance trajectories. In this example, the deviation angle formed is +90°. In other examples, the angle may be different. Robots arriving at the entrances E11, E12, and E13 can either continue straight into the intersection or turn around and take the nearby exits S11, S12, and S13. In this way, each AMR or AGV can take one of the exits S11, S12, and S13. The minimum distance d and the longitudinal offset between positions on the same range belonging to the two parallel trajectories ensure that the AMRs / AGVs in the platoon travel at substantially the same speed, thereby avoiding the risk of collision.

[0058] Optionally, to further ensure collision-free running, when a first robot and a following second robot in the same formation on the same entrance trajectory take a first exit trajectory, the second robot is required to take a second exit trajectory located before the first exit trajectory.

[0059] For example, when two consecutive AMRs in a formation arrive at trajectory E11, the first AMR must take exit S13 and the second AMR must take one of exits S12 or S11.

[0060] Advantageously, when a first row of robots and a subsequent row of robots in the same formation arrive via two parallel entrance trajectories and are intended to use the same exit trajectory, a robot arrives via a first entrance trajectory and a second robot arrives via a second entrance trajectory that is further away from the exit end of said exit trajectory.

[0061] For example, AMRs A3 and C3 can use the same exit without conflict.

[0062] Advantageously, the inlet and outlet trajectories may have the same length. Additionally, at the intersection, the optional radius of curvature is the same along the trajectory in the direction of flow. Advantageously, the distribution section may be unidirectional. This further ensures collision-free traffic.

[0063] 4 shows another embodiment in which the transfer circuit 11 includes, in addition to the distribution section Sd1 described above, a second continuous distribution section Sd2, which may be identical to Sd1 or different, but whose orientation is adapted to the arrangement of the outlets of Sd1. In addition, the same rules as those described above for Sd1 can be applied to Sd2.

[0064] FIG. 5 shows another example of a transport system 12 that includes a redirection region Zi between two distribution sections.

[0065] In this example, AMRs A4, B4, and C4 form a negatively oriented formation that is incompatible with the next distribution section, which is also negatively oriented. To adapt the formation's orientation, an orientation change process is performed in region Zi by accelerating and / or decelerating the robots located on autonomous trajectories T1 and T3 such that C4 moves to the first column R1 and A4 moves to the third column R3.

[0066] In this configuration, the robot can navigate within the distribution section without risk of collision, following the rules described in Sd1.

[0067] 6 shows an example of a sorting installation 100 for carrying out the method according to the invention. Installation 100 includes a sorting area 101 with chutes 102 arranged in several lines. At the exit of the sorting area, an area 103 is provided where AMRs / AGVs arrive after being unloaded into chutes 102. Area 103 is a distribution section that minimizes the number of vehicles required for sorting. Optionally, a reversing section 108 is provided between areas 101 and 103 to correctly reorient AMRs / AGVs leaving sorting area 101.

[0068] At the start of the sorting method, a convoy forms in induction section 104, after which the convoy passes through loading area 105, known to those skilled in the art, to receive the parcels to be sorted. The AMRs then pass through first distribution section 106 and second distribution section 107, which open onto the sorting line of sorting area 101. Finally, each item is unloaded into destination chute 102. In this example, the spacing between the tracks in area 107 and area 103 is equal to L+d, allowing distribution sections 106 and 107 to have the same orientation without risk of collision for the AMR / AGV.

[0069] This example of an application is of course not limiting, as many other applications are possible, for example, a sortation system can be modified by adding additional sortation lines and distribution sections.

[0070] In one variation, area 103 can be simplified to be an accumulation and waiting area where AMRs / AGVs accumulate after unloading into chute 102. In this case, reversing section 108 is not required. Also, in area 103, the track spacing does not need to be equal to L+d.

[0071] Another application is the use of similar transport systems having induction and distribution sections in automated storage facilities. In addition, such facilities are known to include multi-level storage areas and one or more lifting / lowering devices.

[0072] In this case, for example, a storage area can be reserved in front of each lift / lower device if the device is not immediately available when the AMR / AGV arrives.

Claims

1. A method for transporting items (P1, P2, P3, P4, P5) in an intralogistics system (1, 10, 11, 12) using autonomous mobile robots (A, B, C) or automated guided vehicles, each capable of transporting one item (P1, P2, P3, P4, P5) within a transport circuit (2, 20) of the system, the method comprising a step of forming a convoy (C1, C2) comprising at least two mobile robots (A, B, C) traveling at the same speed along at least one section of the circuit (2).

2. 2. The method of claim 1, wherein the formation step (C1, C2) is carried out in a so-called introduction section (Si) and comprises defining a grid of theoretical positions each of which can be occupied by an autonomous mobile robot, the grid comprising a plurality of parallel tracks (T1, T2, T3) and a plurality of successive parallel rows (R1, R2, R3) that intersect with the tracks and form a non-zero angle with the tracks, the formation comprising two or more robots (A, B, C) in different rows (R1, R2, R3) positioned such that two robots in successive rows of the same track are separated by a predetermined minimum distance (d).

3. 3. The method according to claim 2, wherein the formation step comprises a sub-step in which two theoretical positions belonging to two adjacent tracks (T1, T2, T3) of the same row (R1, R2, R3) are offset in the longitudinal direction of the introduction section (Si) by a distance (a) equal to the distance between the two adjacent tracks (T1, T2, T3).

4. 4. The method of claim 3, wherein the rows (R1, R2, R3) in the introduction section (Si) form angles of +45° or −45° with the trajectories (T1, T2, T3), corresponding to a positive or negative orientation of the formation (C1, C2), respectively.

5. 5. The transfer method according to claim 2, wherein a distribution section (Sd1) connected to the introduction section (Si) is added to the transfer circuit (20), the distribution section (Sd1) having one or more parallel robot entrance trajectories (E11, E12, E13) intersecting with several parallel robot exit trajectories (S11, S12, S13), the exit trajectories (S11, S12, S13) forming non-zero deviation angles with the robot entrance trajectories (E11, E12, E13), the method further comprising the step of moving the robots in the formation between the entrance trajectories and the exit trajectories at substantially the same speed.

6. 6. The method of claim 5, wherein an additional distribution section (Sd2) having one or more parallel second robot entrance trajectories (E21, E22, E23) that intersect with one or more parallel second robot exit trajectories (S21, S22, S23) is added to the transfer circuit, the second exit trajectories (S21, S22, S23) forming a deviation angle with the second robot entrance trajectories (E21, E22, E23) that is not zero and, optionally, oppositely oriented to the angle of the distribution section (Sd1), the method further comprising the step of moving the formation at substantially the same speed between at least one of the second entrance trajectories (E21, E22, E23) and the second exit trajectories (S21, S22, S23).

7. 7. A method according to claim 5 or 6, comprising a step of changing the orientation of the formation by accelerating and / or decelerating the autonomous mobile robots (A, B, C) in a reorientation zone (Zi) provided between two consecutive distribution sections (Sd1, Sd2).

8. 8. The method according to claim 5, wherein when a first robot (A, B) and a subsequent second robot (B, C) in the same formation on the same entrance trajectory (E11, E12, E13, E21, E22, E23) take a first exit trajectory (S12, S13, S22, S23), the second robot (B, C) takes a second exit trajectory (S11, S12, S21, S22) located before the first exit trajectory.

9. 9. The method according to claim 5, wherein when robots (A, B) of a first row (R1) and robots (B, C) of a subsequent row (R2) of the same formation arrive via two parallel entrance trajectories and are intended to use the same exit trajectory, the robots (A, B) arrive via a first entrance trajectory and the second robot (B, C) then arrive via a second entrance trajectory that is further away from the exit end of the exit trajectory.

10. The method according to any one of claims 1 to 9, wherein the formation (C1) is separated from the following formation (C2) by a predetermined safety distance (D).

11. A computer program comprising instructions for carrying out the method according to any one of claims 1 to 10.

12. A computer readable medium comprising the computer program of claim 11.

13. 1. An intralogistics transport system, comprising: a number of autonomous mobile robots (A, B, C) or automated guided vehicles, each capable of transporting one object; a ground transport circuit (2, 20) along which the autonomous mobile robot / autonomous guided vehicle can circulate; - a computer program according to claim 11; An intralogistics transport system comprising:

14. An installation (100) for sorting articles, comprising a sorting area (101) and a transport system according to claim 13.

15. 14. An automated material storage facility comprising an item storage area having a plurality of storage levels and lifting and lowering means connecting said levels, said facility further comprising a transfer system according to claim 13.

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