PROCEDURE FOR OPERATING A PLANT

Description

[0001] The invention relates to a method for operating a system.

[0002] It is generally known that logistical tasks in a facility can be carried out using mobile devices such as driverless transport systems (AGVs).

[0003] From the US 2013 / 302132 A1 The closest prior art is a method for maneuvering a handset where all features of the preamble of claim 1 are disclosed.

[0004] From the DE 195 40 928 A1 A positioning method is known.

[0005] From the EP 3 132 859 A1 A conveyor device with collision detection is known.

[0006] The invention is therefore based on the object of making the processes within the system more efficient.

[0007] According to the invention, the object is achieved by the method according to the features specified in claim 1.

[0008] Important features of the invention in the method for operating a system are that the system has a mobile part that can be moved on a travel surface of the system and a load carrier, in particular a load carrier that is arranged stationary in the system, wherein the mobile part has a radar sensor connected to a controller of the mobile part, wherein in a first method step the distance from the radar sensor to the load carrier is determined, in a second method step the mobile part is moved to a position at which the distance between the radar sensor and the load carrier reaches a predetermined target distance, in a third method step the frequency spectrum of an intermediate frequency signal is determined, which is generated by mixing the radar radiation emitted by the radar sensor, in particular towards the load carrier, and received, in particular from the load carrier, in a fourth method step, in particular by means of pattern recognition, the frequency spectrum, in particular the pattern formed by the frequency spectrum, is compared with stored pattern templates and the result of the comparison is passed to the controller, in a fifth method step the controller actuators,such as the drive and / or steering unit of the handset, depending on the result, in particular the control system carries out a control process depending on the result.

[0009] The advantage here is that the control system can execute different control sequences depending on the type of load carrier, whether it is present or absent. For example, if no load carrier is found at the expected location, especially a shelf storage location, the handset can be stopped and waited, or another logistical task can be performed by the handset. However, if, for example, a pallet cage is detected, the handset can be picked up and moved to another location.

[0010] However, if a steel wall box is detected, it can be loaded onto the handset. However, if a Euro pallet is detected, the system first assesses whether or not there is any cargo on the Euro pallet. If there is no cargo, either the cargo being transported by the handset is placed on the Euro pallet, or the Euro pallet is picked up by the handset and transported to another location.

[0011] In an advantageous embodiment, the result of the comparison in the fourth method step is the type of load carrier. This is advantageous because the type of load carrier, for example, a Euro pallet with a load, a Euro pallet without a load, a wire mesh box, or a steel wall box, can be identified using radar sensors. An image analysis unit connected to a camera mounted on the mobile device can be used additionally, but is not necessary. This image analysis reduces the error rate of the radar-based type detection. However, the image analysis unit requires computing time.

[0012] In an advantageous embodiment, a first pattern template is generated from the frequency spectrum of the intermediate frequency signal of the radar sensor upon detection of a grid box, In particular, the grid box has a side wall with a steel grid, in particular the grid openings of which have a maximum clear diameter of less than 5 cm, in particular the grid box is open at the top. The advantage here is that a grid box is recognizable even though it has grid openings and thus only reflects parts of the surface.

[0013] In an advantageous embodiment, a second pattern template is generated from the frequency spectrum of the intermediate frequency signal of the radar sensor when detecting a steel wall box, In particular, the steel wall box has a side wall made of a solid steel wall, in particular, the steel wall box is open at the top. This is advantageous in that it results in strong reflection of radar radiation, thus ensuring good detectability.

[0014] In an advantageous embodiment, a third pattern template is generated from the frequency spectrum of the radar sensor's intermediate frequency signal upon detection of a loaded Euro pallet, particularly where the Euro pallet is made of wood and the load comprises a cardboard box. This is advantageous because a cardboard box surrounding the parts contained in the load, which is arranged on the wooden Euro pallet, reflects only a small amount of radar radiation and is thus easily distinguishable from a wire mesh box and even from a steel-walled box.

[0015] In an advantageous embodiment, a fourth template is generated from the frequency spectrum of the radar sensor's intermediate frequency signal upon detection of an unloaded Euro pallet, particularly when the Euro pallet is made of wood. The advantage here is that, due to the lack of load, no reflection is generated from the expected distance, but rather the radar radiation is reflected by objects further away. This makes it recognizable that there is no load. However, the wooden Euro pallet generates a characteristic reflected signal that is recognizable. Thus, even an unloaded Euro pallet can be recognized.

[0016] Important features one System for carrying out the above-mentioned method is that the system has a mobile part that can be moved on a travel surface of the system and a load carrier arranged in the system, in particular on the travel surface, wherein the mobile part has a controller, an electric drive controllable by means of the controller and a controllable steering unit, wherein a radar sensor is arranged on the mobile part, wherein the radar sensor is connected to the controller arranged on the mobile part for signal transmission, wherein the controller controls the drive and the steering unit depending on the signals of the radar sensor.

[0017] The advantage here is that a specific control sequence can be executed depending on the detected load carrier type. In particular, wire mesh boxes, loaded Euro pallets, unloaded Euro pallets, and steel wall boxes trigger different movement sequences of the mobile unit. These load carriers are preferably arranged at locations in a rack warehouse, and the mobile unit is track-guided so that it can move to a position assigned to each location in the rack warehouse, from which the type of the respective load carrier can be identified using radar sensors. Depending on the detected type, different movement sequences can then be executed over time.

[0018] In an advantageous embodiment, the mobile unit has a track guidance means connected to the controller of the mobile unit, in particular wherein a track guidance means, in particular a metal wire or a metallic cable, is laid along the travel surface in the system. This is advantageous in that the mobile unit can easily reach the position assigned to each space by traveling along the track and approaching the assigned position using a position detection system. From there, detection is then carried out using the radar sensors. In this way, the space is always detected and recorded at the same angle and distance using the radar sensors.

[0019] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0020] The invention will now be explained in more detail using schematic illustrations: In the Figure 1 A mobile unit 1 is shown, which has a radar sensor 2, whose sensitive area 4 is directed towards a first load carrier, namely a Euro pallet with a load. Figure 2 The mobile unit 1 is shown, the sensitive area 4 of the radar sensor 2 is directed towards a second load carrier, namely a steel wall box. Figure 3the mobile part 1 is shown, the sensitive area 4 of the radar sensor 2 of which is directed towards a third load carrier, namely a grid box 31 with a movably arranged flap.

[0021] As shown in the figures, radar sensor 2 has a sensitive area 4, allowing the distance between sensor 2 and objects to be determined. For this purpose, a preferably FCMW radar sensor is used. The sensor signal from sensor 2 is evaluated by mixing the transmitted radar signal with the reflected radar signal received by sensor 2, thus generating an intermediate frequency signal, which is fed to an evaluation unit.

[0022] The evaluation unit is arranged on the handset 1 and preferably determines a frequency spectrum of the intermediate frequency signal by means of Fourier transformation.

[0023] The pattern formed by the frequency spectrum is evaluated by a pattern recognition device, which compares the formed pattern with stored patterns, i.e., pattern templates. As soon as one of the pattern templates is recognized, this information is forwarded from the pattern recognition device to a controller of the handset, which then initiates further control processes for handset 1 based on this information.

[0024] A first template is the stored pattern of the frequency spectrum of a detected grid box 31 with a flap 30 movably mounted thereon. The grid box comprises a metallic grid, in particular a steel grid. Since a grid has continuous grid gaps, the first template differs significantly from the template of a steel-walled box.

[0025] In such a steel wall box 20, the radar radiation is reflected more strongly than in a grid box 31, since the steel wall box 20 has a continuous steel wall.

[0026] A third sample template corresponds to the frequency spectrum pattern of a Euro pallet 5 with a load. The Euro pallet 5 is made of wood and supports a load, which is preferably contained in a cardboard box. Thus, the radar radiation is reflected less by the Euro pallet 5 and its load, especially the cardboard box, than by the steel-walled box 20. Furthermore, the pattern also differs from the pattern of the lattice box 31, since the gaps in the lattice box do not represent a homogeneous surface, particularly in contrast to the steel wall of the steel-walled box and also in contrast to the side of a cardboard box.

[0027] By comparing with another pattern template, it is even possible to determine during pattern recognition whether the flap arranged on a grid box 31 in a movable, in particular displaceable or foldable, manner is arranged in a first or second position, in particular whether the side wall of the grid box 31 is closed or opened by means of the flap.

[0028] The lattice box 31 is open at the top, thus having a cuboid shape. The bottom is connected to the four side walls and has foot areas on the side facing away from the top. The top of the cuboid is constructed without any material, which is why the lattice box 31 is open at the top.

[0029] Likewise, the steel wall box 20 is open at the top, thus having a cuboid shape. The bottom is connected to the four side walls and has foot areas on the side facing away from the top. The top of the cuboid is constructed without any material, which is why the steel wall box 20 is open at the top.

[0030] To minimize error in pattern recognition, the mobile unit 1 moves along a travel surface of a system to a specified target distance from the load carrier. The orientation of the mobile unit 1 relative to the load carrier is also specified, in particular by moving the mobile unit 1 along a track arranged in the system. As soon as the target distance from the mobile unit 1 is reached, the intermediate frequency signal of the radar sensor 2 is evaluated, and the type of load carrier is determined using pattern recognition.

[0031] In this way, the type of load carrier stored in a warehouse for each storage location can be determined, or whether a load carrier is stored at all.

[0032] To minimize error in pattern recognition, only a portion of the sensitive area 4, which can be used for distance determination, is used, namely the detection area 3. This area is positioned at a fixed angle to the travel surface and at a fixed angle to the mobile part, in particular to an axis of a non-steerable wheel of the mobile part 1. This ensures the most uniform boundary conditions possible when performing pattern recognition.

[0033] The radar sensor is preferably operated in the E-band, especially the ISM band, or the W-band. The resolution is between 1 cm and 10 cm, especially 4 cm. Thus, the grid openings of a standard industrial grid box cannot be precisely resolved.

[0034] In further embodiments according to the invention, the radar sensor is operated in the ISM band with a bandwidth of 5 GHz. List of reference symbols

[0035] 1 Handset 2 Radar sensor 3 Detection zone 4 Sensitive zone 5 Euro pallet with load 6 Pick-up device 20 Steel wall box 31 Grid box 30 Movable flap

Claims

1. Method for operating a facility, wherein the facility comprises a movable part (1), which is movable on a movement surface of the facility, and a load carrier, in particular a load carrier which is arranged in a stationary manner in the facility, wherein the movable part (1) comprises a radar sensor (2), which is connected to a controller of the movable part (1), wherein in a first method step the distance from the radar sensor (2) to the load carrier is determined, in a second method step the movable part (1) is moved to a position at which the distance between the radar sensor (2) and the load carrier reaches a predefined target distance, characterized in that in a third method step the frequency spectrum of an intermediate frequency signal is determined, said intermediate frequency signal being generated by mixing the radar radiation emitted by the radar sensor (2), in particular toward the load carrier, and the radar radiation received, in particular from the load carrier, in a fourth method step the frequency spectrum, in particular the pattern formed by the frequency spectrum, is compared with stored pattern templates, in particular by means of pattern recognition, and the result of the comparison is forwarded to the controller, in a fifth method step the controller controls actuators, such as a drive and / or a steering unit, of the movable part (1) as a function of the result, i.e. in particular the controller executes a control sequence as a function of the result.

2. Method according to claim 1, characterized in that in the fourth method step the result of the comparison is the type of load carrier.

3. Method according to at least one of the preceding claims, characterized in that a first pattern template is generated from the frequency spectrum of the intermediate frequency signal of the radar sensor (2) during detection of a wire-mesh crate (31), in particular wherein the wire-mesh crate (31) has a side wall comprising a steel mesh, in particular the mesh openings of which have a maximum clear diameter of less than 5 cm, in particular wherein the wire-mesh crate (31) is open at the top.

4. Method according to at least one of the preceding claims, characterized in that a second pattern template is generated from the frequency spectrum of the intermediate frequency signal of the radar sensor (2) during detection of a steel-walled box (20), in particular wherein the steel-walled box (20) has a side wall formed of a solid steel wall, in particular wherein the steel-walled box (20) is open at the top.

5. Method according to at least one of the preceding claims, characterized in that a third pattern template is generated from the frequency spectrum of the intermediate frequency signal of the radar sensor (2) during detection of a Euro pallet (5) with a load, in particular wherein the Euro pallet (5) is made of wood and the load comprises a cardboard box.

6. Method according to at least one of the preceding claims, characterized in that a fourth pattern template is generated from the frequency spectrum of the intermediate frequency signal of the radar sensor (2) during detection of a Euro pallet (5) without a load, in particular wherein the Euro pallet (5) is made of comprises wood.