METHOD AND ARRANGEMENT FOR LOADING A DRIVERLESS TRANSPORT VEHICLE FOR SINGLE GOODS

Description

[0001] The invention relates to a method according to claim 1 or an arrangement according to claim 10 for loading a driverless transport vehicle for individual goods, wherein the individual goods are transferred from a delivery station to the driverless transport vehicle and the driverless transport vehicle is in motion during the transfer.

[0002] Transport vehicles, especially autonomous or driverless transport vehicles that serve as carriers of goods, are known. For example, US 2013 / 054005 A1 discloses so-called autonomous "bots" that move mobile shelves.

[0003] Suitable transport vehicles for individual goods or cargo are also known, for example, from CN 208018986 U, in which the goods rest on a loading platform on the top of the transport vehicle.

[0004] German patent DE 10 2019 122 055 A1 also describes a small autonomous transport vehicle for individual goods, which stabilizes goods placed on a loading platform during movement by having a raised wall on one side of the loading platform. During transport, the vehicle is always rotated so that acceleration during starting, cornering, and deceleration presses the goods against this raised wall, thus preventing them from falling off.

[0005] To unload individual items, the vehicle's motion vector is changed immediately before or upon arrival at an unloading station. The vehicle's control system and / or at least one guidance device located near the unloading station then align the vehicle so that the path of the goods, which move away from the loading platform due to the change in the velocity vector, ends within a receiving area of ​​the unloading station. In other words, the goods continue moving with their original vector before the change and thus slide off the loading platform of the transport vehicle due to gravity or inertia.

[0006] Conversely, it is analogously known to load the corresponding vehicle with a single item, for which the single item is classically loaded onto the vehicle by means of a conveyor or transferred by the vehicle by means of stripping (cf. https: / / www.youtube.com / watch?v=hlAbmQ9kZOsHowever, the vehicles must either stop or at least slow down considerably.

[0007] From DE 20 2018 101313 U1, an intralogistics loading / unloading station for automated guided vehicles (AGVs) is known, which is configured to load goods onto or unload them from the AGV while the AGV is stationary or while the AGV is synchronously moving laterally past or under the station. DE 20 2018 101313 U1 discloses a method according to the preamble of claim 1 and a device according to the preamble of claim 10.

[0008] From WO 2020 / 242695 A1, a sorting conveyor system is known with a main sorting conveyor that sorts packages directly into destination containers or first onto discharge sorting conveyors and then onto other destination containers. Discharge chutes with multiple destinations serve two or more destination containers. Package detectors recognize packages being delivered to the destination containers to help identify packages that have been sorted into the wrong destination containers.

[0009] In contrast, the object of the present invention is to provide an improved method for loading vehicles that does not have the above disadvantages and, above all, is faster.

[0010] This problem is solved by the method described in claim 1. Advantageous embodiments are described in the dependent claims and the description.

[0011] According to the invention, it has been found that if the individual item is accelerated from the delivery station for transfer and leaves it at such a speed, and the distance between the driverless transport vehicle and the delivery station is such that the individual item undergoes a flight phase between leaving the delivery station and impacting the driverless transport vehicle moving at normal transport speed, the individual item can be transferred without slowing down. The driverless transport vehicle therefore does not need to stop or slow down.

[0012] Individual items are fed to transfer points, for example, via conveyor belts or roller conveyors. The individual items flow in at current speeds of 4 m / s. When transferring to the automated guided vehicle (AGV), the individual items must not be slowed down, otherwise bottlenecks would occur. On the contrary, it is advantageous to transfer the individual items to the AGVs at a higher speed, so that the AGVs maintain greater distances from each other than the individual items on the incoming conveyor system.

[0013] In other words, the individual item is thrown for transfer to the moving automated guided vehicle (AGV), as it is accelerated to such a high speed that it doesn't simply fall when leaving the delivery station or the end of the conveyor line, but continues to move freely. The item thus flies through the air without any support or contact, and the AGV catches it at the end of its calculated trajectory.

[0014] In this context, "flight phase" means that the individual item has no contact with the delivery station or the transport vehicle during this phase of movement. The item is not supported, carried, or resting on anything else. It simply flies passively through the air.

[0015] The invention is preferably used in warehouses, distribution centers, or parcel processing centers where all individual goods or packages are known with regard to their properties and characteristics, in particular their dimensions, mass or weight, and center of gravity. Accordingly, the dispensing station will be connected to a conveyor system of the overall system and supplied with the respective individual goods, which are then transferred to the appropriate automated guided vehicle (AGV) at the dispensing station.

[0016] The properties and characteristics of the individual product can therefore be used to calculate the necessary accelerations or velocities and from these, in turn, the flight paths or trajectories.

[0017] This allows the driverless transport vehicle, moving at normal transport speed, to move in sync with the trajectory of the individual item in order to precisely catch the flying item on its loading platform. In other words, due to the known properties and thus predictable trajectory, the transport vehicle can be moved precisely to the landing point of the item in order to catch it from its loading platform at the correct time, synchronized with the trajectory and speed.

[0018] The dispensing station can thus have sensors at the inlet to determine the identity of each individual item.

[0019] According to the invention, it has been found that a particularly suitable speed for individual items leaving the dispensing station is in the range of 5 m / s to 15 m / s. The conveyor technology can be controlled for the corresponding acceleration using the known data of the individual items. In principle, any type of conveyor technology capable of providing such speeds is suitable, especially for individual items weighing between 1 kg and 100 kg, particularly up to 30 kg, and with standard dimensions. Individual items or packages with standard dimensions are less than or equal to L=675 mm, W=450 mm, H=240 mm, preferably less than or equal to L=480 mm, W=360 mm, H=150 mm.

[0020] The conveying system can be a suitably designed conventional roller conveyor or a belt conveyor. Additional or alternative configurations are also conceivable. In addition to gravity, the contact force can be increased by an additional roller conveyor above the individual item, which exerts a defined force on the item (e.g., via spring tension, hydraulically actuated, or electrically driven). Alternatively, the individual item can be accelerated by lateral pressure rollers. In this case, the rollers below the individual item do not require their own drive.

[0021] Another solution involves pushing the individual item forward using a sliding mechanism. Upon arrival at the transfer roller conveyor, the mechanism is raised, allowing the item to pass underneath. After the item has passed, the slide is lowered and then accelerated linearly towards the discharge point. Suitable linear drives include electric motor spindle drives, hydraulic cylinders, or pneumatic cylinders. In addition to pushing, it is also possible to couple the linear drive to the item from the side or front using a vacuum, and then release this coupling shortly before discharge after the acceleration phase.

[0022] The conveyor system in the discharge station is usually designed so that it runs essentially horizontally and the conveyor section ends at the discharge end. However, it is also conceivable that the conveyor section at the discharge end is not horizontal, but rather inclined upwards like a ramp, so that the individual item leaves the discharge station at a positive angle deviating from the horizontal. This has the advantage that the individual item hits the automated guided vehicle (AGV) with a smaller pitching angle: The pitching motion that occurs when leaving the discharge station, i.e., a rotation around the transverse axis through its center of gravity, is pre-compensated by the positive angle of attack.

[0023] It is also conceivable that the angle of attack can be varied depending on the properties of the individual product.

[0024] This prevents excessive nodding of the individual item, ensuring that the individual item does not nod more than 20° if possible.

[0025] The nodding motion of individual items or packages results from the movement imparted to the package as soon as its center of gravity passes over the "drop edge," while the rest of the package is still resting on the ground. During this time, the package is given a rotational motion; it then continues to rotate during flight.

[0026] This means that the pitch angles upon impact with the automated guided vehicle (AGV) depend on the package length, speed, and flight phase or distance. Surprisingly, the inventors discovered, by comparing various parameter combinations, that pitch angles of up to 20° are particularly suitable for a soft landing. At significantly higher values, the landing on the AGV becomes too harsh.

[0027] Another design involves lowering the entire conveyor system after reaching its final speed or at the end of the acceleration process, allowing the individual item to continue flying parallel to the conveyor system without any pitching motion. In the previous version, the item is subjected to a pitching motion when moving over the edge (end of the conveyor system) if it "tips over the edge." By lowering the conveyor system parallel to and "pulling away" from the item, it continues along its parabolic trajectory and can land parallel to the automated guided vehicle without any pitching motion.

[0028] Therefore, it can be useful if the dispensing station has a dispensing end that can be varied in angle and / or height.

[0029] The automated guided vehicle (AGV) is a standard, industry-standard vehicle equipped with a chassis, either with at least one steered wheel or with a wheel arrangement that enables omnidirectional movement. It is also equipped with a drive on at least one wheel, capable of accelerating the vehicle to the required speed of 5 m / s. Higher speeds of 10 m / s or 15 m / s are also possible and advantageous for increasing throughput, particularly over longer distances. Furthermore, the AGV has a control system combined with sensors and a communication device. The sensors enable it to determine its position within the warehouse. For example, it can...The system uses laser scanners to determine the position by measuring the distance to designated and known points (such as reflectors) via triangulation. Additionally, to increase positioning accuracy during load transfer, it can determine its position relative to the transfer station. Based on this known position, the automated guided vehicle (AGV) can use its controller to plan a trajectory to the transfer point for the delivery of the individual item. This trajectory is communicated to the vehicle via the communication unit, either bidirectionally with the transfer station or by a central control unit that manages both the transfer station and the vehicle. During the approach process, the controller navigates the AGV to the load transfer point on schedule and confirms successful arrival at the transfer station or the central control unit.

[0030] According to the invention, the driverless transport vehicle, as discussed above, is in the correct position at the end of its trajectory at the necessary time to catch the individual goods with its loading platform during its movement. Ideally, it has a speed appropriate to the individual goods, so that landing should be possible without any problems.

[0031] To prevent individual items from sliding or falling during landing, it can still be beneficial for the driverless transport vehicle to have a possibly padded containment wall. Such a containment wall is positioned at the front of the transport vehicle in the direction of travel and thus effectively prevents any slippage.

[0032] One aspect of the present invention is that the movement of the individual item or its trajectory in the flight phase and the corresponding movement of the driverless transport vehicle are synchronized with each other, so that the random transport vehicle can pick up the individual item at the end of the flight phase or end of the trajectory.

[0033] Synchronization can be achieved via a central control system, which handles not only the necessary calculations but also the communication between the individual participants. Alternatively, bidirectional communication between the delivery station and the driverless transport vehicle is possible for the temporal and / or spatial synchronization of the individual goods transfer.

[0034] For communication between the control or delivery station and the driverless transport vehicle, common communication methods can be used: e.g. WLAN or 4G, 5G with protocols based on e.g. MQTT or OPC-UA or DDS.

[0035] The invention relates not only to the method described above, but also to a corresponding arrangement comprising the driverless transport vehicle, the dispensing station, a control system, and, of course, at least one individual item. The dispensing station has a controlled conveyor system with a dispensing end for delivering the individual item to a loading platform of the driverless transport vehicle. The conveyor system, controlled by the system, accelerates the individual item to such a speed that, upon leaving the dispensing station, the item undergoes a flight phase between leaving the dispensing station and impacting the driverless transport vehicle, which is moving at normal transport speed. This ensures that the movement of the driverless transport vehicle is synchronized with the trajectory of the individual item via the system's control.

[0036] It goes without saying that the flying transfer from the drop-off station to the fast-moving transport vehicles takes place in a protected area where personnel have no access or are only allowed access after appropriate clearance and a standstill.

[0037] Typically, the discharge end of the discharge station will have a vertical distance of approximately 0.1 m to 0.3 m compared to the surface of the loading area of ​​the driverless transport vehicles.

[0038] Based on the specified takeoff speeds and vertical distances, the flight times of the individual items range between 0.07 and 0.2 seconds. Accordingly, an individual item covers a flight distance of 0.3 to 1.5 meters, depending on its mass, initial speed, etc.

[0039] The invention allows individual items to be dispensed even faster than they can be supplied. This results in a high throughput.

[0040] Furthermore, the energy required to accelerate the individual item does not need to be supplied by the driverless transport vehicle, but is instead imparted to the item by the stationary drive unit, which is easier to power than a vehicle with its limited battery capacity. This increases the operating time of the vehicles, which only have to absorb friction and drive losses. If the vehicle decelerates along with the load during unloading, some of the kinetic energy supplied by the individual item can be recuperated into the vehicle. It would also be possible to recuperate some of the energy during landing in the vehicle.

[0041] Further details of the invention will become apparent from the following description of exemplary embodiments with reference to the drawing, in which Fig. 1 a schematic side view of various stages of the "drop-off" of a single item from a delivery station onto a driverless transport vehicle; Fig. 2 a schematic side view of an alternative delivery station; Fig. 3 a schematic top view of another delivery station; Fig. 4 a schematic top view of another delivery station; Fig. 5 a schematic top view of another delivery station; Fig. 6 a schematic side view of another delivery station; and Fig. 7 a schematic side view of another delivery station. show.

[0042] The figures show the acceleration of a package P on a roller track 2 of a delivery station 3 of an arrangement 1.

[0043] According to the invention, the package P is accelerated to a speed of 5 m / s in the delivery station 3 for transfer to an AGV as a driverless transport vehicle and dynamically transferred or "thrown" onto the AGV 4, which also moves at such a speed.

[0044] It is shown in Figure 1 A powered roller conveyor 2 carries a package P on it, representing any product. The package P is accelerated to the right on the roller conveyor; the rotational speed of the rollers, symbolized by arrows below the rollers, increases over time. Alternatively, a belt conveyor could be used, which picks up the package on the left side of the belt and accelerates the belt, and thus the package, during transport to the right.

[0045] Below the roller conveyor, an AGV 4 approaches, its speed and position synchronized with that of package P on roller conveyor 2, so that after leaving the roller conveyor at the delivery end 5, package P enters a flight phase at a speed of 5 m / s (step iii) and is thus thrown onto or caught by the AGV 4 (step iv). To prevent package P from slipping off the AGV 4, the AGV 4 has a padded, U-shaped (partially encompassing the loading area) containment wall 6 positioned at the front in the direction of travel.

[0046] The AGV 4 can approach directly below roller conveyor 2, parallel to it. However, it is also conceivable that the AGV 4 approaches on a curved track and only reaches a velocity vector parallel to the roller conveyor at the moment of load transfer. This can have the advantage that the AGV 4 can use a support next to the roller conveyor, which may be needed to stabilize the load during transport, and the rollers can be positioned very close to the AGV's loading platform, resulting in a very small drop height or distance between the end of the delivery and the AGV's loading platform. This avoids stress on the package from acceleration or impact upon landing on the AGV. The approach trajectories are not yet shown in the diagram.

[0047] Additionally, sensors 8 and controllers 7 are provided on the roller conveyor 2, and sensors 9 and controllers 10 are located in the AGV 4. These determine the position and speed of the package P, as well as the position and speed of the AGV. The latter can be done either absolutely, if the absolute position of the roller conveyor is assumed to be known, or relative to the roller conveyor, particularly at the end 5 of the roller conveyor.

[0048] Furthermore, communication between the vehicle and the delivery station is provided via controllers 7 and 10 to coordinate the transfer in terms of time and location. Alternatively, coordination can be carried out by a higher-level controller which, upon arrival of a package at the transfer roller conveyor, assigns the collection order to an AGV and synchronizes the AGV's approach and the package's movement on the roller conveyor.

[0049] In the Figure 1The package rests on the roller conveyor under the influence of gravity, and the acceleration energy is transferred by the frictional force based on its own weight.

[0050] Further embodiments present alternative solutions to improve the contact force or the transmission of the acceleration force to the package P.

[0051] As in Figure 2 As shown, in addition to gravity, the contact force can be increased by an additional roller conveyor 11 above the package P, which acts on the package P from above with a defined force or clamps the package P between itself and the roller conveyor 2 (e.g. by spring preload, hydraulically actuated, electro-motor actuated).

[0052] Alternatively, the package P can be accelerated by lateral pressure rollers 12A, B, as shown in Figure 3 The diagram shows the package P being clamped between them. In this case, the roller conveyor 2 can be designed without a drive.

[0053] Another solution could involve pushing the package P forward using a sliding mechanism 13, 14, as in Figure 4 and 5 shown. The sliding mechanism 13 after Figure 4 The system comprises a height-adjustable crossbar 15, which can be linearly accelerated in the direction of discharge via drives 17 arranged parallel to each other on both sides of the roller conveyor 2. Suitable linear drives include an electric motor spindle drive, hydraulic cylinders, or pneumatic cylinders (not shown).

[0054] Upon arrival of package P at the transfer roller conveyor 16, the crossbar 15 is raised, allowing the package to pass underneath. After package P has passed, the crossbar 15 is lowered and then accelerated linearly in the direction of the discharge.

[0055] According to Figure 5The drive 17 can be designed as a circulating, driven belt 18 with a driver 15 as a crossbar for accelerating the package P. The belt drive 18 is controlled in such a way that the package is accelerated in a controlled manner.

[0056] Besides pushing, it is also conceivable to couple the linear drive to the package from the side or front using negative pressure and to release this coupling again after the acceleration phase shortly before the drop.

[0057] According to Figure 6 The delivery end 5 of the delivery station 3 can be angled, i.e., executed at an angle 19° relative to the horizontal H, in order to influence the trajectory and in particular a nodding of the packet P.

[0058] In the Figure 7In the variant shown, the delivery station 3 has 5 height-adjustable supports 20 at the delivery end, so that the conveyor technology can be lowered as a whole from a height X1 to a lower height X2 from the horizontal H after reaching the final speed or at the end of the acceleration process, so that the individual goods continue to fly parallel to the conveyor technology without a pitching movement.

Claims

1. Method for loading a driverless transport vehicle (4) for individual products with an individual product (P), wherein the individual product (P) is transferred from a delivery station (3) to the driverless transport vehicle (4), and the driverless transport vehicle (4) is moving during the transfer, characterised in that the individual product (P) is accelerated for the transfer from the delivery station (3) and leaves the latter at such a speed and the distance between the driverless transport vehicle (4) and the delivery station (3) is of such a size that the individual product (P) passes through a flight phase between leaving the delivery station (3) and landing on the driverless transport vehicle (4) moving at a normal transport speed.

2. Method as claimed in claim 1, characterised in that the driverless transport vehicle (4) moving at a normal transport speed moves in a manner synchronised to the flight path of the individual product (P) in order to catch the flying individual product on its loading surface.

3. Method as claimed in claim 2, characterised in that the speed of the individual product (P) and the synchronisation of the movement of the driverless transport vehicle (4) are controlled based on the properties of the individual product (P).

4. Method as claimed in any one of the preceding claims, characterised in that the individual product (P) is accelerated to a speed of at least 5 m / s.

5. Method as claimed in any one of the preceding claims, characterised in that the individual product (P) leaves the delivery station (3) at a positive angle (19) deviating from the horizontal.

6. Method as claimed in any one of the preceding claims, characterised in that the delivery station (3) has a sensor system (8) at the in-feed in order to determine the identity of the respective individual product (P).

7. Method as claimed in any one of the preceding claims, characterised in that the delivery station has a delivery end (5) which is variable in terms of angle (19) and / or height (X1, X2).

8. Method as claimed in any one of the preceding claims, characterised in that the driverless transport vehicle (4) has a possibly cushioned catch wall (6).

9. Method as claimed in any one of the preceding claims, characterised in that bidirectional communication takes place between the delivery station (3) and driverless transport vehicle (4) for the time- and / or position-synchronisation of the transfer of the individual product (P).

10. Arrangement (1) for loading a driverless transport vehicle (4) for individual products with an individual product (P), in particular for performing a method as claimed in any one of the preceding claims, comprising a driverless transport vehicle (4) for individual products, a delivery station (3) for individual products and at least one individual product (P), as well as a controller (7, 10), wherein the delivery station (3) comprises a controlled conveyor system (2, 13, 14) having a delivery end (5) for delivering the individual product (P) to a loading surface of the driverless transport vehicle (4), characterized in that the conveyor system (2, 13, 14), controlled via the controller (7), accelerates the respective individual product (P) to such a speed that the individual product (P), when leaving the delivery station (3) via the delivery end (5) of the conveyor system, passes through a flight phase between leaving the delivery station (3) and landing on the driverless transport vehicle (4) moving at a normal transport speed, and that the movement of the driverless transport vehicle (4) is synchronised to the flight path of the individual product (P) via the controller (7, 10).