Method for identifying objects in a warehouse by means of a ground vehicle and ground vehicle

Abstract

The invention relates to a method for identifying objects in a warehouse by means of a ground vehicle, comprising the following steps: emitting an identification signal by means of a transmitting device of the ground vehicle; detecting, by means of a receiving device of the ground vehicle, the identification signal reflected by objects in the surroundings as signal echoes; assigning a spatial angle and a reception time to each of the signal echoes; checking whether a plurality of the signal echoes is assigned to the same spatial angle; if a spatial angle is assigned to a plurality of signal echoes, evaluating the signal echo which last arrives in the receiving device for this spatial angle depending on the reception time for the identification of the object; identifying the object on the basis of the signal echoes.

Description

Technical Field

[0001] The present invention relates to a method for identifying objects in a warehouse by means of a ground transport vehicle, and a ground transport vehicle for implementing the method. Background Technology

[0002] Ground transportation vehicles typically include multiple sensors, such as laser scanners, for identifying their surroundings. These sensors can identify objects in the environment surrounding the ground transportation vehicle and control the vehicle based on these identified objects; for example, the vehicle can be controlled to bypass an object identified as an obstacle. Similarly, cargo carriers to be received, such as pallets, can be identified and then received by the ground transportation vehicle in this way.

[0003] A related identification method is known from EP3316181A1. In this method, a rendering image of an object located near a ground transport vehicle is generated based on data received via a 3D camera, and this rendering image is compared with a template, i.e., a predefined pattern. The template can be stored in an analysis and evaluation device of the ground transport vehicle. During this so-called template matching, it can be checked whether the image received via the 3D camera, for example, a pallet, is sufficiently consistent with the stored image of the pallet as a template. If there is sufficient consistency, the object is identified as a pallet. The ground transport vehicle can then receive the pallet, particularly automatically, by moving the load forks of the ground transport vehicle into the pallet recess and then lifting the pallet.

[0004] In known methods, object recognition may fail. This is, for example, in the described template matching if the image of the detected pallet does not sufficiently match the template. As the inventors recognize, this is especially true if the goods arranged on the pallet are wrapped with a partially transparent film. Films are commonly used in logistics to secure goods. Here, it often happens that the film also at least partially obscures the pallet's recesses. The received image of the pallet then deviates excessively from the template.

[0005] Within the scope of object recognition, alternative pallets may also be used to identify free space within warehouse shelving as an object. This recognition may fail if, for example, a film is hung from the upper shelf plane into the lower free space. Partially transparent segmented curtains (used to separate different warehouse areas) may also act as obstacles, hindering successful identification of objects located behind them. In particular, even if travel is possible within the prescribed usage range, these partially transparent segmented curtains may appear as obstacles.

[0006] Obstacle identification in road traffic is also known to be performed using LIDAR systems, such as those described in WO2019 / 164959A1, WO2019 / 226487A1, or WO2019 / 222684A1. These LIDAR systems emit laser pulses and analyze and evaluate echoes over time or reduce the signal-to-noise ratio through multiple measurements. Therefore, obstacles obscured by fog or smoke should also be identified. Summary of the Invention

[0007] Building upon existing technology, this invention aims to provide a method or ground transport vehicle that can more reliably identify objects in a warehouse, particularly those obscured by at least partially transparent barriers.

[0008] The method for identifying objects in a warehouse by means of ground transportation according to the present invention includes the following steps:

[0009] -Identification signals are emitted using the transmitting devices on ground transportation vehicles;

[0010] - Detect the identification signals reflected by objects in the surrounding environment as signal echoes using the receiving device of a ground transportation vehicle;

[0011] - Assign spatial angle and reception time to each signal echo in the signal echo;

[0012] - Check whether multiple signal echoes in the signal echo are matched with the same spatial angle;

[0013] -If a spatial angle is associated with multiple signal echoes, the analysis and evaluation are performed based on the signal echo that last arrives at the receiving device for that spatial angle at the receiving time for object identification.

[0014] - Identify objects based on signal echoes.

[0015] The ground transport vehicle according to the invention is constructed for carrying out the method. The method according to the invention can therefore be implemented using the ground transport vehicle according to the invention. The description of the method applies accordingly to the ground transport vehicle, especially to its analysis and evaluation apparatus, and vice versa.

[0016] The ground transport vehicle according to the present invention includes a transmitting device for emitting an identification signal, a receiving device for detecting the identification signal reflected by an object in the surrounding environment as a signal echo, and an analysis and evaluation device. The analysis and evaluation device is configured to: assign a spatial angle and a reception time to each signal echo in the signal echo; check whether multiple signal echoes in the signal echo are associated with the same spatial angle; if a spatial angle is associated with multiple signal echoes, the analysis and evaluation uses the signal echo that last arrives at the receiving device for that spatial angle at the reception time as the basis for object identification; identify the object based on the signal echo; and control the ground transport vehicle based on the identified object.

[0017] According to the present invention, object identification is performed by emitting an identification signal and analyzing and evaluating the signal echo. The identification signal can be, for example, an optical signal, especially a laser signal. The transmitting and receiving devices can be part of a common transmitting and receiving device, especially part of a sensor unit. For example, a LIDAR (“light detection and ranging”) can be set as the transmitting and receiving device, and the LIDAR outputs three-dimensional ambient data including two-dimensional ambient data or depth information. A “time-of-flight” camera can also be provided. However, the identification signal can also be an acoustic signal, especially an ultrasonic signal. Thus, the ambient environment can be detected by means of an ultrasonic sensing device.

[0018] According to the present invention, a spatial angle and a reception time are assigned to each signal echo received by the receiving device. This allows for the generation of a rendering of the environment surrounding the ground vehicle, particularly a rendering of objects within that environment. This can involve, for example, a two-dimensional rendering. A three-dimensional rendering can also be generated by taking distance information into account. The distance information can be derived, particularly by taking into account the transmission time of the signal and its propagation time.

[0019] The inventors recognized that partially transparent obstacles in the environment surrounding a ground transport vehicle can cause multiple signal echoes to occur at the same spatial angle. Thus, when an emitted identification signal hits a partially transparent obstacle, a portion of the signal is reflected and thus reaches the receiving device as a first signal echo, while the portion of the identification signal transmitted through the partially transparent obstacle is reflected on an object behind it, such as a pallet, and received in the receiving device as a second signal echo arriving later from the same spatial angle. In the known methods for object identification described at the beginning, this can result in the partially transparent object being identified, but objects located behind it not being identified. If, for example, a pallet is to be identified as an object as described at the beginning, a film hanging in front of the pallet recess for securing goods arranged on the pallet may obstruct the identification of the pallet located behind it from the perspective of the ground transport vehicle.

[0020] According to the solution of the present invention, when multiple signal echoes in the signal echo are matched with the same spatial angle, the signal echo that last arrives at the receiving device for the corresponding spatial angle is analyzed and evaluated for object identification. The analysis and evaluation of the signal echo that last arrives at the corresponding spatial angle for object identification can indicate that the last signal echo is assigned to the object. In particular, only the last signal echo can be assigned to the object. Previously arriving signal echoes for the same spatial angle can be ignored, for example, during the analysis and evaluation. Previously arriving signal echoes can also serve as the basis for identifying partially transparent objects, as will be explained later. The analysis and evaluation of the signal echo that last arrives at the corresponding spatial angle for object identification can also indicate that the previously arriving signal echo at that spatial angle is replaced, or that the signal echo arriving at the receiving device at the same spatial angle is not assigned to the object. Thus, for example, image points based on previous signal echoes can be deleted within the scope of the analysis and evaluation based on other signal echoes at the same spatial angle, as will be explained later. Therefore, by analyzing and evaluating the last arriving signal echo for object identification, for example, a pallet can be reliably identified even if its recess is partially or completely covered by a transparent film. The transparent film is "seen through." Ground transportation vehicles can then be controlled based on the identified object.

[0021] Thus, for example, when a pallet is identified, a ground transport vehicle can—especially fully automatically—move its load forks into the pallet recess and pierce the transparent film with the fork tines. The transparent film extending into the free space can also be ignored, for example, when identifying free space in a shelf. Partially transparent segmented curtains can also be ignored, allowing the ground transport vehicle—especially fully automatically—to travel through them. The ground transport vehicle can see through the segmented curtains and reliably identify objects behind them, such as the base to be passed or potential obstacles, like other ground transport vehicles. The solution according to the invention is particularly simple and efficient thanks to the principle of matching the last arriving signal echo with the object, especially relative to methods that perform matching by comparing with a known pulse shape of the signal echo. Therefore, it is not necessary to know the known pulse shape for the solution according to the invention. In fact, the exact pulse shape of the signal echo may be unimportant, as it depends instead on the reception time.

[0022] The receiving device can measure and thus detect multiple successive signal echoes, particularly persistently. The receiving device can be activated for a predetermined time period after the identification signal is emitted by the transmitting device. Thus, according to one design, it can be specified that for object identification, only signal echoes arriving at the receiving device within a preset time period after the identification signal is emitted are used or analyzed for evaluation. According to another related design, the preset time period can be based on the maximum expected measurement distance. This increases the probability that the signal echo arriving at the receiving device is also actually the signal echo of the emitted identification signal. This is particularly important when object identification according to the invention is based on the last signal echo arriving at the receiving device. Limiting to a time period related to the maximum expected measurement distance prevents the use of subsequently arriving measurement signals (e.g., caused by multiple reflections) as the basis for object identification, which could lead to erroneous object identification. In particular, the object to be identified might be missed.

[0023] According to one design, an object is identified by generating a presentation image of the object based on signal echoes and comparing the presentation image with a template, wherein the object is considered identified when there is sufficient consistency between the presentation image and the template. Template matching can thus be performed as mentioned at the beginning. For example, a presentation image of the front of a pallet can be generated from the signal echoes. This image of the front of the shelf can then be compared with a template of storage on the front of the pallet, i.e., a model image, using an analysis and evaluation device of a ground transport vehicle. If there is sufficient consistency between the presentation image and the template, the ground transport vehicle identifies the pallet and can accept it. The presentation image can be generated in such a way that the corresponding last signal echo is assigned to the object, but previous signal echoes at the same spatial angle are ignored, as mentioned above. The object can therefore be identified solely based on the last arriving signal echo. Object identification can also be additionally based on previously arriving signal echoes. Thus, image points for the presentation image, especially the entire front image of the shelf, can be generated first, for example, based on a first signal echo. Then, corresponding image points can be deleted or replaced for the spatial angle at which another last signal echo arrives.

[0024] According to one related design, a representation of an object is generated by creating a two-dimensional data record by projecting image points onto a projection plane. The signal echo detected by the receiving device can be understood here as image data comprising a large number of image points. This is also referred to as a point cloud. These image points are projected onto the projection plane. The projection plane is preferably chosen such that it corresponds to a hypothetical arrangement of the object to be identified. The image points distributed on the projection plane can be understood as a two-dimensional representation of the object. Three-dimensional object recognition can also be achieved. According to another design, additional data records are created, comprising depth profiles along lines at positions on the projection plane, and these additional data records are compared with a predefined depth profile pattern assigned to the object. If sufficient consistency is determined during the comparison, the object is ultimately identified. Therefore, additional template matching is performed according to this design. This improves recognition reliability. Further details regarding this template matching can be found in EP3316181A1.

[0025] If the last arriving signal echo, i.e., the signal echo generated by an object located behind a supposedly transparent object, should be indistinguishable from signal noise, then an expected value can be calculated and considered when selecting the appropriate signal echo. The expected value can, for example, be based on the geometry of the cargo carrier. If the geometry—even weakly—is supported by multiple adjacent depth values, then the corresponding object is considered identifiable. The expected value can also be obtained by mapping the hall floor.

[0026] According to one design, when multiple signal echoes in a signal echo are aligned with the same spatial angle, the signal echoes that previously arrived at the receiving device are assigned to a second object, and this object is identified as partially transparent. As explained, when identifying the first object, the signal echoes that last arrived at the receiving device are analyzed and evaluated, thereby ignoring the previously arrived signal echoes caused by the partially transparent obstacle. However, according to this design, the partially transparent obstacle itself is also identified, i.e., it is identified by analyzing and evaluating the previously arrived signal echoes. In particular, the signal echoes that first arrive at the receiving device can be assigned to the second object, and this object is thus identified as partially transparent. The identification of the second object as a partially transparent object can, in particular, include: in principle, in the case of multiple signal echoes, assigning the first arriving one to the partially transparent object. In particular, a rendering map of the partially transparent second object can also be created. Thus, the analysis and evaluation device can create a second point cloud for the transparent second object in addition to the point cloud for the first object mentioned above. Thus, when targeted elimination is desired, transparent obstacles can be specifically identified. In principle, this allows for more accurate classification of partially transparent objects, such as determining whether it involves a film covering cargo or a segmented curtain. When the partially transparent object is a film covering cargo, it allows for checking, for example, whether the cargo's fasteners are loose or yielding. In principle, other rendering images can also be generated, especially as point clouds. Thus, the first point cloud can be based on the strongest signal echo, while the second point cloud is based on the second strongest or second strongest echo. The first point cloud can also be based on the signal echo seen from the foremost point in the ground transportation vehicle, while the second point cloud is based on the signal echo following it. In this sense, third, fourth, or even additional point clouds can also be created.

[0027] If an object is identified as a segmented curtain, a design scheme can specify an adaptation speed for the ground transport vehicle. In this sense, the ground transport vehicle can be controlled based on the identified second object. This allows the ground transport vehicle's speed to be reduced, thus ensuring it travels carefully through the segmented curtain. This prevents damage to the segmented curtain and the goods being transported by the ground transport vehicle. This speed reduction is also significant because object identification by the ground transport vehicle may be hindered by the curtain during passage. If a partially transparent object is to be identified, for example, as a film of goods stored on a pallet, the ground transport vehicle can puncture the film when moving the load fork into the pallet recess, as already mentioned. Here, a speed adaptation for the ground transport vehicle, particularly a speed reduction, can also be implemented. This is meaningful, for example, when dealing with relatively light goods that might otherwise be moved by puncturing the film before the pallet recess by means of the load fork. The ground transport vehicle can be notified, for example, via a warehouse management system, that light goods are involved.

[0028] According to one design, the motion of the ground vehicle itself is considered when identifying an object. For example, the vehicle's direction of travel, speed, acceleration, and / or deceleration can be considered as the motion for object identification. In particular, object identification can be performed multiple times, for example, at different locations where the ground vehicle occupies the position within its own motion range. Thus, according to one design, a first presentation image of the object is generated based on signal echoes detected at a first location of the ground vehicle, and the first presentation image is compared with a first template. A second presentation image of the object is generated based on signal echoes detected at a second location of the ground vehicle, and the second presentation image is compared with a second template. The object is considered identified when sufficient consistency exists not only between the first presentation image and the first template but also between the second presentation image and the second template. According to this design, image sequences with two or more object presentation images can be generated and compared with corresponding templates. This allows for a more reliable conclusion as to whether the signal echo is caused by a partially transparent object or an opaque object. It also eliminates the possibility of multipath reflections, which could otherwise lead to erroneous object identification. Therefore, even in the case of multipath reflection, multiple signal echoes can be generated at the same spatial angle. However, when the ground vehicle is in motion, such multipath reflections typically no longer occur, or at least no longer occur, at the same spatial angle. A partially transparent second object, along with an opaque first object following it, continues to cause at least two signal echoes to arrive at the same spatial angle. It is also possible to identify, by considering the motion of the ground vehicle itself, whether the assumed signal echoes might simply be noise. This design can also be used, for example, to examine the reliability of relatively weak signal echoes and thereby remove noise. If the image points generated by the signal echoes move in coordination with the motion of the ground vehicle itself, then identifiable objects may be involved, and noise may not be involved.

[0029] As already mentioned, ground transport vehicles can be controlled based on the identified object. Thus, according to one design, the ground transport vehicle can automatically orient itself based on the identified object. As already mentioned, the ground transport vehicle can, for example, automatically move its load forks into a pallet recess, even if the pallet recess is covered by a partially transparent film. Similarly, the ground transport vehicle can automatically travel through a partially transparent segmented curtain. Partially automated control is also conceivable. Thus, according to one design, the operator can be given visual and / or acoustic instructions based on the identified object to perform or initiate the orientation or movement of the ground transport vehicle. The ground transport vehicle can include corresponding indicating devices. For example, the operator can be instructed on a display how the load forks should be oriented to achieve pallet reception. Acoustic feedback can occur in the case of correct orientation. In the case of partial automation, visual or acoustic indication can be given that the pallet is identified and the ground transport vehicle accurately orients itself accordingly. Automatic orientation of the ground transport vehicle can be achieved through interaction between the operator and the ground transport vehicle, for example, through holding and pressing corresponding operating elements.

[0030] According to one design scheme, surrounding environmental elements are considered in order to identify an object. From this, it can be inferred whether the identified signal echo truly represents the object from the surrounding environment where the object is typically expected to be located. Thus, a wall behind a storage area can, for example, indicate that the detected signal echo indeed originates from a pallet located in the storage area. The wall can also indicate that a corresponding signal echo can be obtained with a high probability at that location. Attached Figure Description

[0031] The invention is described below with reference to the accompanying drawings. In the drawings:

[0032] Figure 1 A ground transport vehicle according to the invention is shown in a schematic diagram from above and from the side.

[0033] Figure 2 This illustrates a schematic recognition of a tray through template matching.

[0034] Figure 3 This demonstrates the identification of tray failure due to a tray recess covered by a partially transparent film.

[0035] Figure 4 , 5 The pallet identification according to the present invention is shown.

[0036] Figure 6 A schematic diagram showing the generation of signal echoes is provided.

[0037] Figure 7 This illustrates the identification of free space within warehouse shelving, and

[0038] Figure 8 The image shows a ground vehicle traveling through a partially transparent, segmented curtain. Detailed Implementation

[0039] Unless otherwise specified, the same reference numerals in the following figures denote the same objects.

[0040] Figure 1 A ground transport vehicle 10 according to the present invention is shown, wherein the ground transport vehicle 10 is in Figure 1 It is shown in a top view and in Figure 1 Figure b shows a side view. The ground transport vehicle 10 includes a drive section 12 and a load section 14. The load section 14 has a load fork with two fork teeth 16. A sensor unit 18 is arranged at the top of one of the fork teeth 16 as a transmitting and receiving device. The sensor unit emits an identification signal and detects the identification signal reflected by objects in the surrounding environment of the ground transport vehicle 10 as a signal echo. The sensor unit 18 may, for example, be a 2D or 3D LiDAR. The sensor unit may also be arranged in other locations, such as on the pole of the ground transport vehicle.

[0041] Based on the signal echoes received by the sensor unit 18, the analysis and evaluation device 20, arranged in the drive section 12 of the ground transport vehicle 10, generates a rendering image of objects in the surrounding environment of the ground transport vehicle. The analysis and evaluation device 20 compares these rendering images with stored templates, wherein if there is sufficient consistency between the corresponding rendering image and the corresponding template, the object based on the template is considered to be identified. This template matching is described in detail in EP3316181A1.

[0042] exist Figure 2 As can be seen in a, sensor unit 18 emits identification signal 19a and receives the reflected identification signal 19b as a signal echo. Figure 2 In the illustration shown in figure a, the load forks of the ground transport vehicle are raised to the height of the pallet 22 supported on the rack support 20. The pallet 22 has goods 24. Furthermore, the rack back wall 26 is visible. The sensor unit 18 emits a large number of identification signals 19a at different spatial angles, which are reflected on the pallet 22 and on the rack support 20. This generates a signal echo, denoted as E in the figure, and yields... Figure 2The presentation images visible in b. These presentation images show the front image of the shelf generated by the signal echo E, along with the front of the pallet 22 and the front of the shelf support 20, in white. The surrounding areas are shown in black, for which either no signal echo was received or no signal echo was presented. Thus, the goods 24, in particular, may also be visible in presentation image D, but are not shown. The two rectangular pallet recesses of the pallet 22 are clearly visible in presentation image D. The shelf back wall 26 located behind the pallet also generates a signal echo in principle. However, this signal echo is not considered for object recognition. This can be achieved, for example, by using only the signal echo that arrives at the sensor unit 18 within a preset time period after the recognition signal is emitted for object recognition. Figure 2 The visible representation of image D in b is... Figure 2 The template T, visible on the right side of image b, is compared to the template T. Template T is stored in the analysis and evaluation device 20 as a model image of the pallet's front. If there is sufficient consistency between the presentation image D and the template T, the analysis and evaluation device 20 identifies the pallet 22 itself. In this example, the line of sight towards the front of the pallet 22 is free, thus the presentation image D and the template T are well consistent, and the pallet can be identified. However, it is possible that the line of sight towards the front of the pallet is obscured, for example, by a partially transparent film, which is typically used to secure goods arranged on the pallet.

[0043] This is Figure 3 As shown in section a, the goods 24 are wrapped with a partially transparent film 25. As can be seen, the film 25 extends downwards from the goods and also surrounds the pallet 22, partially obscuring the pallet recess. The identification signal 19a emitted by the sensor unit 18 is reflected on the film 25, thereby obtaining the identification signal using known identification methods. Figure 3 The image visible in b. The image presented in tray 22 and Figure 3 The difference in template T, as shown again on the right side of b, is so strong that tray 22 itself is not recognized. This invention is thus formed.

[0044] As the inventors have recognized, the partial transparency of the thin film 25 generates multiple signal echoes at the same spatial angle. Figure 4As shown, only the first portion of the identification signal 19a is reflected as signal 19b on the thin film 25, while the second portion of the identification signal 19a passes through the thin film, passes the tray recess behind it, and is reflected as signal 19c on the shelf back wall 26. Thus, a first signal echo E1 is obtained on the front of the tray and on the thin film 25 there, and a second signal echo E2 is obtained on the shelf back wall 26. Therefore, multiple signal echoes, i.e., at least signal echoes E1 and E2, arrive at the sensor unit 18 at the same spatial angle. In principle, additional signal echoes can also be identified, for example, by identifying additional signal echoes generated by the reflection of the identification signal on the thin film 25 located on the back side of the tray 22. According to the invention, for the spatial angle corresponding to the multiple signal echoes, only the signal echo that last arrives at the sensor unit 18 is analyzed and evaluated for object recognition. Thus, in this example, only signal echo E2 serves as the basis for object recognition, but signal echo E1 is not. Therefore, the partially transparent thin film 25 can be seen through to a certain extent. Thus, even though the tray recess is covered by the film 25, the tray 22 still provides the desired appearance. Figure 2 The image shown on the left in b is a completely frontal view. Therefore, template matching with template T can be successfully performed, and the object is recognized as a tray.

[0045] exist Figure 5 In this arrangement, sensor unit 18 is positioned at a lower height than tray 22. However, tray 22 can still be successfully identified. In this arrangement, a second echo E2 is obtained by reflecting the identification signal onto the lower side of the tray's upper plate. Correspondingly, another echo can also be obtained... Figure 2 The presentation image D is shown on the left side of b. Therefore, the tray was successfully identified again when analyzing and evaluating the second echo E2 according to the present invention, because the presentation image and the template have sufficient consistency.

[0046] Figure 6 The signal progression is schematically illustrated. The signal peak emitted and received by sensor unit 18 can be seen. The signal peak, emitted by sensor unit 18 as an identification signal, strikes the transparent object 30, whereby the signal is partially reflected and partially transmitted. The reflected portion first returns to sensor unit 18 and is recorded as a first signal echo. The transmitted portion is completely reflected by the opaque object 32, partially passes through the transparent object 30, and then returns to sensor unit 18, where it is recorded as a second signal echo.

[0047] exist Figure 7The diagram illustrates another application of the method according to the invention. A front view of the shelf 40 together with the cargo carrier 42 (also constructed as a pallet) located therein is shown. The pallet 42, arranged on the upper shelf plane, carries goods with a film 44 attached, wherein a portion 46 of the film 44 extends downward into the shelf plane below it. This portion 46 of the film thus interferes with the identification of the free space 48 by the ground transport vehicle 10. Thus, in known methods, the portion 46 of the film 44 hanging below is identified as an obstacle, and the pallet space is not identified as free. However, thanks to the method according to the invention, the portion 46 of the film 44 hanging below can be seen through by analyzing and evaluating the echo of the last arriving signal in the manner described above, and thus the free space 48 itself is identified. The cargo carrier can then be unloaded in this free space without regard to the portion 46 hanging below.

[0048] Figure 8 The diagram illustrates a ground vehicle 10' traveling through a partially transparent segmented curtain 50. The ground vehicle 10' has a sensor unit 18' that observes the ground ahead of it along its direction of travel. An identification signal 19' emitted by the sensor unit 18' generates a first echo E1 on the partially transparent segmented curtain 50 and a second echo E2 on a second ground vehicle 60 located behind the segmented curtain 50. By analyzing and evaluating the second echo E2, the ground vehicle 10' can thus see through the segmented curtain 50 and identify the ground vehicle 60 behind it. Furthermore, it is determined that the segmented curtain 50 itself does not constitute an obstacle, allowing the ground vehicle 10' to pass through it. If no second ground vehicle should be located behind the segmented curtain, the ground area behind the segmented curtain might be identified as an object.

[0049] List of reference numerals

[0050] 10 Ground transportation vehicles

[0051] 10′ Ground transportation vehicles

[0052] 12 drive section

[0053] 14 Load Section

[0054] 16-pronged teeth

[0055] 18 sensor units

[0056] 18′ sensor unit

[0057] 19a identification signal

[0058] 19b reflected identification signal

[0059] 19c reflected recognition signal

[0060] 19′ Identification signal

[0061] 20 Shelf load-bearing components

[0062] 22 trays

[0063] 24 Goods

[0064] 25 partially transparent films

[0065] 26 Shelf Back Wall

[0066] 30 Transparent Objects

[0067] 32 Opaque Objects

[0068] 40 shelves

[0069] 42 Cargo carrier

[0070] 44 film

[0071] 46 Thin film portion

[0072] 48 Free Space

[0073] 50-section transparent segmented curtain

[0074] 60 Second Ground Transportation Vehicle

[0075] D-presentation diagram

[0076] T template

[0077] E1 First Signal Echo

[0078] E2 second signal echo

Claims

1. A method for identifying objects in a warehouse by means of a ground transport vehicle (10), the method comprising the steps of: The identification signal is emitted by means of the transmitting device of the ground transport vehicle (10); The ground transport vehicle (10) uses a receiving device to detect the identification signal reflected by the object (22) in the surrounding environment as a signal echo (E1, E2). Assign a spatial angle and a receiving time to each of the signal echoes (E1, E2); Check whether multiple signal echoes (E1, E2) are matched with the same spatial angle; If a spatial angle is associated with multiple signal echoes (E1, E2), the signal echoes (E1, E2) that last arrive at the receiving device for that spatial angle at the receiving time are analyzed and evaluated for identification of the object (22). The object (22) is identified based on the signal echoes (E1, E2); In the case of multiple signal echoes for each spatial angle, the signal echo (E1) that arrives at the receiving device before the last signal echo (E2) to arrive at the receiving device is assigned to the second object, and the second object is identified as a partially transparent object.

2. The method according to claim 1, characterized in that, For the identification of the object (22), only the following signal echoes (E1, E2) are analyzed and evaluated, which arrive at the receiving device within a preset time period after the identification signal is emitted.

3. The method according to claim 2, characterized in that, The preset time period is based on the maximum expected measurement distance.

4. The method according to any one of claims 1 to 3, characterized in that, The object (22) is identified by generating a rendering image (D) of the object (22) based on the signal echoes (E1, E2) and comparing the rendering image (D) with a template (T), wherein the object (22) is considered to be identified when there is sufficient consistency between the rendering image (D) and the template (T).

5. The method according to claim 4, characterized in that, A rendering (D) of the object (22) is generated by creating a two-dimensional data record by projecting image points onto a projection plane.

6. The method according to claim 5, characterized in that, An additional data record is created, comprising a depth profile along a line at a position on the projection plane. This additional data record is compared with a predefined depth profile pattern assigned to the object, and if sufficient consistency is determined during the comparison, the object is ultimately identified.

7. The method according to claim 1, characterized in that, The second object is identified as a film (25, 44) or a segmented curtain (50).

8. The method according to claim 7, characterized in that, When the second object is identified as a film (44) or a segmented curtain (50), the speed of the ground transport vehicle (10) is adapted.

9. The method according to any one of claims 1 to 3, characterized in that, The motion of the ground transport vehicle (10) itself is taken into account for the identification of the object.

10. The method according to any one of claims 1 to 3, characterized in that, A first presentation image of the object is generated based on the signal echo detected at a first location of the ground transport vehicle (10), the first presentation image is compared with a first template, a second presentation image of the object is generated based on the signal echo detected at a second location of the ground transport vehicle (10), the second presentation image is compared with a second template, and the object is identified when there is sufficient consistency between the first presentation image and the first template and between the second presentation image and the second template.

11. The method according to any one of claims 1 to 3, characterized in that, The ground transport vehicle (10) is controlled by the automatic orientation or movement of the ground transport vehicle (10) based on the identified object.

12. The method according to any one of claims 1 to 3, characterized in that, The orientation or movement of the ground transport vehicle (10) is visually and / or acoustically indicated to be performed or triggered by the operator of the ground transport vehicle (10) based on the identified object.

13. The method according to any one of claims 1 to 3, characterized in that, In order to identify the object, surrounding environmental elements are taken into account.

14. The method according to claim 13, characterized in that, To identify the object, consider the wall located behind the storage area.

15. A ground transportation vehicle, the ground transportation vehicle comprising a transmitting device for emitting identification signals, a receiving device for detecting identification signals reflected by objects in the surrounding environment as signal echoes (E1, E2), and an analysis and evaluation device (20), wherein, The analysis and evaluation device (20) is configured to: assign a spatial angle and a reception time to each of the signal echoes (E1, E2); check whether multiple signal echoes (E1, E2) are associated with the same spatial angle; if a spatial angle is associated with multiple signal echoes (E1, E2), then the analysis and evaluation is performed on the signal echo that last arrives at the receiving device for that spatial angle based on the reception time for the identification of the object; identify the object based on the signal echo; control the ground transport vehicle (10) based on the identified object; assign the signal echo (E1) that arrives at the receiving device before the signal echo (E2) last arrives at the receiving device in the case of multiple signal echoes for each spatial angle to a second object, and identify the second object as a partially transparent object.

Images