Modular system for recording the positions of linearly transported objects

Abstract

Module system (10) for detecting positions of linearly transported objects on a linear transport device (100), in particular on a conveyor belt, with a direction of travel and a width direction (B) perpendicular to it, comprising: - a plurality of camera modules (12), each comprising a housing (14) and at least one camera unit (16), wherein the at least one camera unit (16) is configured to detect a width range of the linear transport device (100) and objects located thereon; and - a control unit (18) which is configured to receive image data from the camera modules (12); wherein the camera modules (12) are arranged side by side in the width direction (B) of the linear transport device (100) and are each operationally coupled to the control unit (18) for the transmission of image data.

Description

[0001] The present invention relates to a modular system for detecting the positions of linearly transported objects on a linear transport device, in particular on a conveyor belt with a direction of travel and a width direction perpendicular to it, and to a system comprising a linear transport device and such a system.

[0002] Several applications exist where the positions of objects transported linearly by a linear transport device in industrial plants need to be tracked. One example is the tracking of individual products on a conveyor belt of a picking line in a packaging plant. In such a case, the specific task is to precisely determine the positions of the corresponding products on the conveyor belt to control a subsequent gripping robot, enabling it to be positioned appropriately for grasping the products. Another conceivable application is quality assurance, where the precise position of a transported product must also be known.

[0003] For this purpose, prior art has often used camera devices with several cameras in a single elongated housing, with the corresponding cameras arranged in a row transverse to the direction of travel of the corresponding linear transport device in order to be able to capture it in its own dedicated monitoring area transverse to the direction of travel of the conveyor belt.

[0004] However, it becomes apparent that conveyor belts of varying widths require camera systems with correspondingly adapted dimensions and a different number of cameras. This leads to a lack of flexibility, as a separate type of camera system must be provided and maintained for every conceivable width of such a linear transport device, resulting in high costs and significant effort in warehousing and distribution. Consequently, the supply of spare parts for camera systems known from the prior art is also associated with increased effort.

[0005] Therefore, there is a need for an improved system that eliminates the disadvantages of the state of the art described above and is characterized by a high degree of flexibility in its use with different types of conveyor belts or similar devices for the linear transport of objects.

[0006] To solve this problem, the invention proposes such a system comprising a plurality of camera modules, each comprising a housing and at least one camera unit, wherein the at least one camera unit is configured to capture a width range of the linear transport device and objects located thereon, and a control unit configured to receive image data from the camera modules, wherein the camera modules are arranged side by side in the width direction of the conveyor belt and are each operationally coupled to the control unit for the transmission of image data.

[0007] Accordingly, according to the invention, it is possible to address different widths of conveyor belts or similar linear transport devices for objects by arranging a corresponding number of camera modules next to each other in a modular manner and coupling them with a single control unit, so that the modular use of the corresponding camera modules results in increased flexibility with regard to the resulting overall system.

[0008] On the one hand, the control unit can be provided externally as an independent unit separate from the camera modules, while on the other hand, it is also conceivable to integrate the control unit into one of the camera modules. The former embodiment is characterized by the fact that providing the control unit externally results in even greater flexibility and modularity, and the control unit can be easily replaced, for example, in the event of a defect. Conversely, an embodiment with a control unit integrated into one of the camera modules is characterized by the fact that installation space and connections for an external control unit become unnecessary, and consequently, in certain applications, the integration of the modular system according to the invention into a corresponding system can be simplified.

[0009] While it is conceivable to provide a certain number of different types of camera modules, each of which can be combined with one another to achieve a variety of different widths of the resulting system according to the invention, the concept of reducing variants in the system according to the invention can be further developed by having at least some, preferably all, of the camera modules be identical in construction, for example with a housing length of approximately 600 mm and / or containing two or eight camera units. In this way, in the specific example mentioned, overall system lengths of multiples of 600 mm can be achieved, which corresponds to the widths commonly used for conveyor belts and similar transport systems.

[0010] It should be noted that the corresponding camera modules can easily protrude laterally beyond the transport device, provided that suitable image processing by the control unit ensures that the data from individual camera units capturing areas beside the conveyor belt are handled differently than data from camera units that actually depict an area of ​​the conveyor belt being monitored. Naturally, it would also be possible to selectively deactivate one of the camera units if, in such a case, it is positioned laterally next to the transport device.

[0011] As already indicated, in the system according to the invention, at least some, preferably all, of the camera modules can comprise a plurality of camera units, each configured to capture a specific width of the conveyor belt, preferably arranged side by side in the width direction and / or being of identical construction. It should be noted that the housing length of the camera modules mentioned in the preceding paragraph also refers to the width direction of the respective conveyor belt when mounted, meaning that the camera modules extend along the width direction of the conveyor belt with their longitudinal direction.

[0012] Furthermore, the system according to the invention can also include a triggering unit which is operationally coupled to the camera modules and configured to control the camera modules and thus their individual camera units for coordinated triggering, wherein the triggering unit can preferably be integrated with or operationally coupled to the control unit or a control unit of the transport device. This coordinated triggering of the individual camera units of the camera modules, for example at a predetermined recording frequency, ensures that the linearly transported objects can be captured appropriately, for example by matching the triggering frequency of the camera modules to the transport speed of the linear transport device for the objects.For example, the trigger frequency can be selected so that a photograph is taken each time the transport device has moved the objects by an amount along the longitudinal direction of the transport device which corresponds to the recording area of ​​the camera units in this longitudinal direction of the transport device.

[0013] To further simplify the integration of the individual camera modules into the system according to the invention, the housings of these camera modules can each be provided with a connection system that enables mechanical and, optionally, electrical and / or electronic coupling of the camera modules to one another. Accordingly, for example, the camera modules can be simply plugged together using appropriate mechanical, electrical, and / or electronic connectors, or a corresponding snap-fit ​​connection, or a connection using additional connecting elements such as screws and the like, can be provided for coupling the camera modules to one another. Alternatively, however, it would also be possible to install the camera modules individually on a higher-level structure, such as a mounting frame or the like, without coupling the housings of the camera modules to one another.In this context, it should also be noted that the data connection between the camera modules and the control unit could in principle also be established wirelessly, whereby in such a case both generally accessible protocols, such as Bluetooth, or proprietary protocols could be used.

[0014] In this context, the camera modules, particularly in the case of a wired connection, can also be configured for plug-and-play operation, whereby the overall system can be configured to trigger the corresponding operational coupling via a connection using the connection system. The connection of one of the camera modules via the connection system can thus be reported to the system's control unit, which can then appropriately initialize the resulting overall system with regard to the data processing of the image data supplied by the camera units and, if applicable, also the triggering unit.

[0015] Consideration can be given to connecting the camera modules to each other via a daisy-chain connection for the transmission of image data and / or for controlling the triggering and / or for an electrical supply, whereby such a connection generally refers to a series connection of the corresponding components within a bus system.

[0016] Although different types of camera units can be integrated into the system according to the invention, for example ultraviolet cameras, scanner units, line sensors and / or line cameras can be used, it is particularly advantageous for cost and integration reasons to use optical 2D cameras or 3D cameras with light field technology.

[0017] Furthermore, the control unit can also be configured to process the image data supplied by the camera units using object recognition, whereby, based on this image processing, further processed data can be output and / or used by the control unit, for example to control a downstream component of the corresponding system.

[0018] Furthermore, the system can be configured to be calibrated by means of a reference pattern attached or attachable to the linear transport device, by comparing the image data captured by the camera modules, whereby the corresponding reference pattern may in particular include QR codes. Such calibration can be carried out, for example, by placing or otherwise attaching a grid of separate, different QR codes to the linear transport device, so that all camera units can each capture at least a part of the grid, whereby a comparison of the individual camera images and a determination of the actual coordinates for each of the camera units can then be performed.

[0019] According to a further aspect, the present invention relates to a system comprising a conveyor belt or other linear transport device with a direction of travel and a lateral direction perpendicular thereto for the linear transport of objects, as well as a system according to the invention of the type just described. As already indicated above, a triggering unit can be provided here, which can be operationally coupled or integrated with a control unit of the conveyor belt in order to be able to adjust the corresponding triggering rate or targeted triggering times depending on the movement states of the conveyor belt.

[0020] Furthermore, the system according to the invention can comprise at least one gripper unit which is operationally coupled to the control unit of the system in order to be operated on the basis of positions of objects to be gripped detected by means of the system, i.e. to be able to pick up such objects in a targeted and precise manner.

[0021] Further features and advantages of the present invention will become even clearer from the following description of an embodiment thereof, when this is presented together with the enclosed Fig. 1 is considered.

[0022] This Fig. Figure 1 shows a schematic representation of a modular system according to the invention for recording the positions of linearly transported objects in a purely schematic representation.

[0023] This involves in Fig. 1 The modular system as a whole is designated by reference numeral 10 and comprises a plurality of camera modules 12, in this case in particular two camera modules 12, each of which comprises a housing 14 and a plurality of camera units 16. These camera units 16 are each configured and arranged to capture a width range of a linear transport device 100 and objects located thereon, whereby both the in Fig. The arrangement of the camera units 16 shown within the housing 14 allows for image capture, for example, through windows, or alternatively, for the camera units to be mounted on the outside of a corresponding housing. Fig. Figure 1 shows the corresponding transport device purely schematically as an endless conveyor belt 100 with width direction B and an associated control unit 102.

[0024] In the example shown of a system 10 according to the invention, each of the camera modules 12 comprises a total of seven camera units 16 arranged side by side; however, any other number of camera units 16 in such camera modules together with correspondingly different dimensions of the associated housings 14 of the camera modules 12 are also conceivable, wherein in a single installed system 10, in principle, either only a single type of camera module 12 or different types thereof with different dimensions can be used.

[0025] Furthermore, the system 10 includes an external control unit 18, which is coupled to each of the camera modules 12, specifically via a daisy chain. This means that the control unit 18 is initially connected directly to only one of the camera modules 12 via a wired connection. However, data is then transmitted between the individual camera modules 12 via a bus system using inputs and outputs ETH1 and ETH2, so that ultimately the control unit 18 receives data from all of the camera modules 12 in this way. Each of the camera modules 12 is equipped with its own control unit 20 for controlling the corresponding bus system. Additionally, the power supply to the individual camera modules 12 is provided in a similarly interconnected manner via power-in and power-out inputs and outputs.

[0026] Furthermore, it should be noted that a connection to the corresponding control unit 102 of the transport device 100 is also established via a daisy chain. This control unit is configured to coordinate the triggering of the individual camera modules 12 and the camera units 16 contained therein, and thus serves as a triggering unit within the meaning of the present invention. This trigger signal is also accordingly looped through the individual camera modules 12 via trigger input and trigger output, enabling coordinated operation of the individual camera modules 12.

[0027] Finally, it should be noted that the housings 14 of the camera modules 12 are provided for mechanical, electrical and electronic coupling with a suitable connection system 22, which is located in Fig.Figure 1 is only schematically indicated, so that, among other things, plug-and-play operation is enabled as soon as the individual camera modules 12 are coupled to each other via the respective connection system 22 and the last camera module 12 in the series is connected to the external control unit 18. Based on the detection of the number and positions of the individual camera modules 12, the control unit can then perform a suitable initialization to put the overall system 10 into operation and subsequently control its operation.

Claims

[1] Modules system (10) for detecting positions of linearly transported objects on a linear transport device (100), in particular on a conveyor belt, with a direction of travel and a width direction (B) perpendicular to it, comprising: - a plurality of camera modules (12), each comprising a housing (14) and at least one camera unit (16), wherein the at least one camera unit (16) is configured to detect a width range of the linear transport device (100) and objects located thereon; and - a control unit (18) which is configured to receive image data from the camera modules (12); wherein the camera modules (12) are arranged side by side in the width direction (B) of the linear transport device (100) and are each operationally coupled to the control unit (18) for the transmission of image data. [2] System (10) according to claim 1, wherein the control unit (18) is provided external to the camera modules (12) as an independent unit. [3] System (10) according to claim 1, wherein the control unit (18) is integrated into one of the camera modules (12). [4] System (10) according to one of the preceding claims, wherein at least some, preferably all, of the camera modules (12) are identical in construction, in particular with a housing length of about 600 mm and / or 2 or 8 camera units. [5] System (10) according to one of the preceding claims, wherein at least some, preferably all, of the camera modules (12) comprise a plurality of camera units (16), each of which is configured to capture its own width range of the transport device (100), wherein they are preferably arranged side by side in the width direction (B) and / or are of identical construction. [6] System (10) according to one of the preceding claims, further comprising a triggering unit (102) which is operationally coupled to the camera modules (12) and is configured to control the camera modules (12) to trigger in a coordinated manner, wherein the triggering unit is preferably integrated or operationally coupled with the control unit (18) or by a control unit (102) of the transport device (100). [7] System (10) according to one of the preceding claims, wherein the housings (14) of the camera modules (12) are provided with a connection system (22) which enables a mechanical and, if necessary, electrical and / or electronic coupling of the camera modules (12) to each other. [8] System (10) according to one of the preceding claims, wherein the camera modules (12) are configured for plug-and-play operation, wherein the system (10) is in particular configured to trigger a corresponding operational coupling by connecting via the connection system (22). [9] System (10) according to one of the preceding claims, wherein the camera modules (12) are connected to each other via a daisy chain for the transmission of image data and / or for controlling the triggering and / or for an electrical supply. [10] System (10) according to one of the preceding claims, wherein the camera units (16) are designed as 2D cameras or 3D cameras using light field technology. [11] System (10) according to one of the preceding claims, wherein the control unit (18) is further configured to process the image data supplied by the camera units (12) by means of object recognition. [12] System (10) according to one of the preceding claims, wherein the system (10) is configured to be calibrated by means of a reference pattern attached or attachable to the transport device (100) by means of a comparison of the image data recorded by the camera modules (12), wherein the reference pattern may in particular comprise QR codes. [13] Annex, comprising: - a linear transport device (100), in particular a conveyor belt, with a direction of travel and a width direction (B) perpendicular to it for the linear transport of objects; and - a system (10) according to any of the preceding claims [14] System according to the preceding claim and at least claim 6, wherein the triggering unit is operationally coupled to or integrated with a control unit (102) of the transport device (100). [15] System according to one of claims 13 and 14, further comprising a gripper unit which is operationally coupled to the control unit (18) of the system (10) in order to be operated on the basis of positions of objects to be gripped detected by means of the system (10).

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