Method for generating a basis for navigation for a navigation in a sales area

Abstract

The invention relates to a method for generating a basis for navigation for a navigation in a sales area, having the following steps, namely: - detecting the magnetic field along a movement path in the sales area using at least one spatially variable magnetic field-detection device which moves along the movement path in the sales area, - carrying out a computerized production of a location reference in the sales area for the magnetic field detected at the respective location along the movement path, and - storing the detected magnetic field and the location reference thereof in the sales area in the form of a digital magnetic field map.

Description

[0001] title

[0002] Procedure for creating a navigation basis for navigation in a sales area

[0003] Description

[0004] Technical field

[0005] The invention relates to a method for creating a navigation basis in a sales area.

[0006] background

[0007] When digitizing a sales area, such as the sales floor of a supermarket, autonomous robots are used today. These robots move relatively slowly and space-consumingly through the supermarket and use their cameras to digitally record the inventory on shelves using optoelectronic means.

[0008] Digital images created in this way are of very good quality, are essentially free of optical distortions and are therefore ideally suited for digitizing the sales area by creating a "realogram," which represents the actual inventory on the shelf at the time of optoelectronic recording.

[0009] This type of digital representation of the sales area primarily serves the purposes of merchandise and inventory management in the store's sales area. However, navigation within the sales area is not possible based on such a digital representation.

[0010] Against this background, the invention has set itself the task of creating a navigation basis that enables navigation in the real sales area.

[0011] Summary of the invention

[0012] This object is achieved by a method according to claim 1. The subject matter of the invention is therefore a method for creating a navigation basis for navigation in a sales area, which method has the following method steps, namely: detecting the magnetic field along a movement path in the sales area with the aid of at least one location-variable magnetic field detection device which is moved along the movement path in the sales area, and establishing a location reference in the sales room for the magnetic field detected at the respective location along the movement path, and storing the detected magnetic field and its location reference in the sales area in the form of a digital magnetic field map.

[0013] This object is achieved by a navigation method according to claim 14. The subject matter of the invention is therefore a navigation method for navigating in a sales area, which comprises the following method steps, namely: detecting the magnetic field at the location of a navigation device, and determining the location of the navigation device in the sales area with the aid of a digital magnetic field map in which the magnetic fields present at locations in the sales area are stored.

[0014] The invention is based on the finding that different locations in a sales area can be essentially uniquely described by the local magnetic field present there. This is due to the fact that the global Earth's magnetic field is locally individualized in a sales area by the multitude of magnetic field-influencing objects installed there, and without major changes to the arrangement or existence of these objects, the local individuality of the magnetic field is essentially maintained.

[0015] The magnetic field present along the movement path is thus recorded, digitized, and made available for further use with the help of the magnetic field detection device. The recording can essentially be continuous, quasi-continuous, or sequential at predefined time intervals, or even at specific times. For example, a motion or acceleration sensor of the magnetic field detection device can be used to trigger the recording of the magnetic field at the respective location along the movement path when movement or acceleration is detected. A commercially available magnetometer can be used to record the magnetic field, providing a three-dimensional or vectorial digital data representation of the detected magnetic field. Such magnetometers are already built into modern smartphones and form the basis for a function often referred to as a "digital compass."

[0016] In order to subsequently utilize the multitude of magnetic field detections along the movement path for navigation, a location reference is established for each of these magnetic field detections automatically – i.e., computerized, i.e., with the help of a computer that is either built into the magnetic field detection device or located externally (e.g., in an external data processing device). For each magnetic field measurement, which indicates the local magnetic field at the location of its detection along the movement path, the entered location along the movement path is determined and recorded (stored), which will be discussed below.

[0017] Magnetic field-based navigation—that is, the use of knowledge of the local magnetic field and its location reference—has also proven particularly advantageous because it eliminates the need for essentially permanent availability, i.e., the transmission of additional radio beacon signals, which would be necessary for radio-based navigation indoors, since the magnetic field used for location determination and, subsequently, for navigation, is always present. The starting point for navigation is first determining the location of the navigation device, which in turn is based solely on detecting the magnetic field at the location of the navigation device. The location corresponding to the detected magnetic field is then determined using the magnetic field map.

[0018] The sales area can, for example, be a sales room in a supermarket with all of its fittings and fittings, such as shelves, baskets, tables, sales islands, etc. for presenting goods. The sales area can also be a storage area, for example in a building materials store or a logistics center, etc., where, in addition to the aforementioned shelves, baskets, tables, etc. for presenting or storing goods, heavy-duty shelving is also set up in a sales hall or warehouse or in an outdoor area. The term sales area is not restricted to the aforementioned supermarket or building materials store, etc., but can include a wide variety of retail and wholesale sectors. The term sales area can also include a combination of indoor and outdoor areas, as well as the checkout areas, where, for example, customers may...waiting in a queue to pay for the goods they have selected, or other areas not directly reserved for the sale of goods, such as the customer service center or a parking lot.

[0019] The magnetic field detection device can be moved externally. In this case, it is moved directly or indirectly by a person, such as an employee or a customer. The person can move it while carrying the magnetic field detection device. In this way, the magnetic field detection device is moved directly. However, the person can also move another object, which in turn carries the magnetic field detection device. In this way, the magnetic field detection device is moved indirectly. However, the magnetic field detection device can also be self-moving. In this case, it has a movement device for autonomous driving or (radio-based) remote-controlled driving. The movement device can, for example, have a chassis with motorized drive of edges, rollers or chains, etc., and steering capability. The movement is controlled by an on-board computer of the magnetic field detection device.

[0020] Establishing the location reference can be based on various measures, which are discussed in detail below. In any case, the recorded magnetic fields are digitally stored together with their location in the sales area. The location reference refers to the location at which the magnetic field was recorded in the sales area, i.e., the original recording location. Data pairs in the form of a digital representation of the recorded magnetic field and a digital representation of the recording location are stored in a data structure, which is subsequently referred to as a digital magnetic field map. This map indicates the magnetic fields recorded at different locations in the sales area.

[0021] Further, particularly advantageous embodiments and developments of the invention emerge from the dependent claims and the following description. For example, the trajectory in the sales area can be predefined, i.e., known. The direction of movement along the trajectory and the speed can also be defined. Thus, the location reference along the defined trajectory—even in the case of minor deviations from the defined trajectory or slight irregularities in speed—is obtained with a good approximation by the product of the measured value times the time. If the magnetic field is detected at defined times, the relationship between the location along the trajectory and the magnetic field detected there is immediately available and stored.

[0022] Since the data processing device stores the overall plan of the sales area in digital form, the predefined movement path can be computerized directly in this plan and the recorded magnetic fields can be assigned to the relevant locations in the sales area, thus creating the magnetic field map.

[0023] To establish the location reference during magnetic field detection along the movement path, conventional methods can also be used, such as the use of radio signals with known radio signal parameters, which—according to a first variant—are emitted by radio transmitters whose locations in the sales area are known. Such transmitters can be formed, for example, by radio beacons or access points, etc. Their signals can be received by the magnetic field detection device and used there for triangulation to determine the relative location in relation to the radio transmitters. Since the location of the radio transmitters in the sales area is also known, the respective detected magnetic field can also be located in relation to the sales area.

[0024] This type of location determination can also be implemented - according to a second variant - in such a way that the magnetic field detection device has a transmitter for transmitting a radio signal with known radio signal parameters and that this radio signal is received by several radio receivers positioned at known locations in the sales area.

[0025] The location information in the sales area obtained by evaluating the received radio signals can be logged along with the recorded magnetic fields, so that a location reference of the recorded magnetic fields in the sales area is established.

[0026] In this case, it is assumed that the data processing device digitally stores the overall map of the sales area together with – according to the first variant – the positions of the radio transmitters or – according to the second variant – the positions of the receivers. Thus, the determined relative position of the magnetic field detection device in relation to – depending on the selected variant – either the radio transmitters or the radio receivers also directly determines the locations of the magnetic field detection in the sales area, which are logged along with the magnetic fields detected there, thus creating the magnetic field map.

[0027] Once the location reference has been established, the radio signal is no longer required for further location determination and subsequent navigation.

[0028] Particularly in a sales area in which other radio systems for e.g. general data transmission (WLAN, Bluetooth, ZigBee, etc.) or a special radio system for controlling electronic display devices (such as electronic shelf labels) are already active, it has proven particularly advantageous if the location reference is established with the aid of a location-variable camera device (3), which camera device (3) is moved along with the magnetic field detection device and creates a digital recording of the surroundings of the movement path of the magnetic field detection device in the sales area (27).

[0029] This measure ensures that both the detection of the magnetic field and the creation of the image take place at essentially the same location, namely the location where the two devices, i.e., the camera device and the magnetic field detection device, are currently located. Although these are essentially two devices, they can be considered to be located at a single location with a good approximation.

[0030] The statements made in connection with the discussion of the terms "externally moved" and "self-moved" now also apply to the camera device. This solution also fundamentally allows for the simplest possible temporal synchronization of the respective activities of the devices (devices), i.e. the detection of the magnetic field and the creation of the recording. For example, a common time base can be used for both devices. For example, one of the devices can provide its own time base for the other device. Each device can also have its own time base, with the two time bases being synchronized with each other, and both devices start their respective activities together at the same time and subsequently carry out further activities synchronously.Since—as will be discussed in more detail below—a spatial reference can be established for the recording itself, this spatial reference of the recording is also available as a spatial reference for the detected magnetic field. Thus, the spatial reference is established based on the recording.

[0031] In this context, it has proven particularly advantageous if the magnetic field detected at the respective location of the movement path and the image taken at this location are digitally linked.

[0032] The recorded magnetic field and the created image can be transmitted separately in their digital representation to a higher-level data processing device and logically connected or linked there, for example by saving it in a data structure as a data record. The connection between the created image and the recorded magnetic field, and thus their common reference to one and the same location where the magnetic field was recorded and the image was created, can be established by means of a running index that is embedded in both digital representations or by transmitting time data that indicates the time at which the magnetic field was recorded and the image was created. The index specifies the sequence of activities (detection of the magnetic field and creation of the image) and pairs two such events with identical index values.The time specifies when the activities (detection of the magnetic field and creation of the image) occurred and pairs two such events with identical time information. The continuous index can also have a time reference, for example, if the occurrence of two adjacent index values ​​always coincides with the elapse of a predetermined, known time period. Since both devices (the camera device and the magnetic field detection device) are designed separately, they also have separate radio communication devices to transmit their respective data—representing the detected magnetic field on the one hand and the created image on the other—to the data processing device, possibly together with the time information and / or the index values.

[0033] The camera device and the magnetic field detection device moving with it can also be integrated in a combination device and thus use a common radio communication module to transmit the detected magnetic field and the created image, possibly together with the time information and / or the index values, to a data processing device where the connection is made.

[0034] In this context, it has proven particularly advantageous that the connection of the detected magnetic field and the created image takes place in the combination device which has the magnetic field detection device and the camera device.

[0035] Based on this measure, the combination device can generate one or more data packets that bundle the events (detected magnetic field and created image) or a single data stream containing the connected events (detected magnetic field and created image) including their time reference (or their index reference). This avoids individual transmission of the events in separate data transmission sequences. This measure also allows for optimal utilization of the decentralized data processing power available at the combination device for the connection, while simultaneously maintaining more efficient post-processing at the higher-level (central) data processing facility, because already connected events arrive there.

[0036] Thus, on the one hand, according to a first embodiment, in the case of a design of the camera device as a still image camera which is designed to generate still images, the respective still image can be provided together with the magnetic field detected in a temporally corresponding manner to the still image.

[0037] The data packets mentioned above are suitable for this purpose; they are always transmitted when the still image is created and the magnetic field is recorded at essentially the same time.

[0038] On the other hand, according to a second embodiment, in the case of a design of the camera device as a video camera which is structured in video frames for generating a video recording, the respective frame of the video recording can be provided together with the magnetic field recorded in a temporally corresponding manner to the respective frame of the video recording.

[0039] The aforementioned data stream is suitable for this purpose because the video recording is also available in the form of a video data stream structured in video frames. The magnetic field detected for each video frame can be embedded in the video data stream in addition to the respective video frame and thus transmitted to the data processing device.

[0040] However, the transmission can also be carried out in such a way that the video data stream is transmitted in a conventional (standardized) manner and whenever a magnetic field is detected, which can occur, for example, at periodic time intervals, the detected magnetic field is identified with the video frame number of the temporally associated video frame, i.e. a data packet comprising the detected magnetic field and video frame number is transmitted to the data processing device in addition to the video data stream.

[0041] In order to obtain the most extensive possible detection of the magnetic field in the sales area, in particular on the movement paths intended for the movement of people, which people extend, for example, between shelves or in other words along shelf aisles, it has proven advantageous to detect the magnetic field several times along at least partially different movement paths in the sales area.

[0042] Since the movement path typically has a limited (often quite narrow) width, different movement paths are possible along this width, and thus different local magnetic fields can be detected along these different movement paths. The multitude of magnetic field detections present along a section of the movement path—that is, the magnetic field values ​​present around a location in the sales area (vector magnetic field values) as well as their differences from one another—form a characteristic magnetic fingerprint for that location. Since the navigation device is usually in motion, this circumstance can be used to locate its "position" within the magnetic field map as precisely as possible.

[0043] This means that not only can a linear magnetic field measurement be performed along a single movement path and used for subsequent navigation. Rather, a multitude of spaced-apart, adjacent movement paths that pass through a movement path or a designated area for people to stay, called an area, can generate a meaningful group of magnetic field measurements for this area. These measurements can be used to describe the magnetic field-based location within this area. If these measurements along different movement paths are accumulated (stored) over time, a meaningful density of magnetic field values ​​is obtained for the affected part of the sales area. This circumstance contributes significantly to the accuracy of the resulting navigation within the sales area.With regard to the origin of the magnetic field recordings for the area, it is irrelevant whether the multitude of movement paths for this area are traversed systematically, i.e. planned, or whether the movement paths arise randomly over time.

[0044] The location-variable camera device can - as already mentioned - be designed to capture a scene located within its capture range in the form of still images or video recordings. It generates either a digital still image or a series thereof, or a digital video recording. It can also be provided that the camera device, e.g. depending on requirements, generates both a still image and a video recording, whereby the still image and the video recording can be created at different times or a still image can be generated during the video recording (e.g. from the ongoing video recording). For this purpose, the camera device has the means usually provided for this purpose, such as a lens and an image sensor, whereby objects located in a capture range of the camera or a scene are projected or imaged through the lens onto the image sensor.Based on this projection, the (typically semiconductor-based) image sensor generates a digital image of the object or scene within the camera's detection range. The camera's electronics, which include at least one programmable processor and peripheral electronics for providing the functions of the camera device, further process the created digital image. The resulting digital image of the object or scene can be digitally buffered in the camera device and / or, if necessary, compressed to reduce data volume. It can then be transmitted to a data processing device using a radio stage, such as an IoT (Internet of Things) radio stage that uses the 4G or 5G ("fifth-generation technology standard for broadband cellular networks") or subsequent radio standards. Other radio technologies can also be used for this purpose, such as common WLAN standards such as IEEE 802.11.g, IEEE 802.11h, IEEE 802.11b (also known as WiFi 4) or subsequent standards.

[0045] The data processing device can be a local computer or server belonging to the sales area operator, a data center assigned to the sales area operator that is accessible via the internet, or a cloud-based software solution hosted in a data center (a server farm) and available to the sales area operator via the internet. Software is executed on the data processing device. The images from the variable-position camera device and the fixed-position camera device are fed to the software in digital form. The software processes these images using the functionalities discussed below.

[0046] Using the image(s) captured by the location-variable camera device, a digital image of the sales area can now be created. According to this aspect, generating the digital image of the sales area involves processing the surroundings of the movement path in the sales area captured by the at least one location-variable camera device using image processing software, in particular using software measures known in technical jargon as computer vision. As a result of the processing, a virtual space is created as a digital image of the sales area.

[0047] This virtual space can be made accessible to human-perceivable visualization with the help of a visualization device, in particular a screen or a device known as a virtual reality headset.

[0048] Specifically, image processing software can be used to create the virtual space. This software recognizes objects (shelf aisles, shelves, baskets, tables, etc.) in the sequence of images taken along the movement path, whether this is a series of still images or a video recording, digitally describes these objects, arranges them together and thus creates a digital representation of the sales room.

[0049] To support this processing, reference points can also be provided in the sales area that are known to the image processing software because they were previously stored there. These reference points can be radio beacons (known under the technical term "radio beacon") that emit a signal that is received, for example, by the variable-position camera and used to determine the relative position to the radio beacon. This information is made available to the image processing software so that the image captured with the variable-position camera device can be more precisely located in relation to the actual sales area. However, the reference points can also be visually perceptible reference elements or reference signals whose position in the sales area is known or which can be used to determine a clear location in the sales room. These can be simple geometric figures.These can also be coded information carriers in the form of, for example, a QR (quick response) code, an infrared light signal, or a laser light signal. These visually perceptible reference elements are contained in the images from the variable-position camera device; they can be identified there (and possibly decoded if they contain coded information). Their meaning is known to the image processing software because it was stored in advance or the method of processing the visually perceptible reference elements or signals was programmed in advance. Such reference elements or signals can be used, on the one hand, to narrow down the position of the variable-position camera device and, on the other hand, to locate the images created with the variable-position camera device in the digital image of the sales area.

[0050] However, the creation or construction of the virtual space can also be carried out completely autonomously, i.e., without the use of reference points in the sales area, with the help of image processing software. The use of software measures known in technical jargon as computer vision, also known as "machine vision" in German and synonymously as "computer vision," has proven particularly advantageous in this context. The field of computer vision was well known at the time of application. The software measures used there allow images captured by cameras to be processed and analyzed in a variety of ways in order to understand their content or to extract geometric information in order to create the virtual space as a "digital twin" of the real sales area.The "digital twin" represents a data structure in which the geometric information or objects recognized with the help of the CV, as well as their spatial relationships to one another, are stored. For example, in a business premises, the aforementioned furnishings can be easily recognized, as well as the aisles between them, their course, and their orientation to one another. For example, the data structure can store vectors that define corner points or intermediate points for the recognized objects or structures, which serve to delimit the objects or structures. These vectors can refer to an origin and / or to neighboring objects or structures. In order to be able to reproduce the resulting 3D polygons (or polygon meshes), which describe the recognized geometric information and ultimately the recognized objects, in a clearly recognizable, human-perceivable form, the 3D polygons can be covered with a texture.This texturing of the 3D polygons can be achieved, for example, using a recording from a position-variable camera and / or from any stationary cameras provided to convey a realistic impression. Instead of recording, the texture can also be created using predefined image elements to achieve a more abstract, possibly less detailed representation.

[0051] Where appropriate, for the sake of simplicity, reference to the software measures of computer vision will be referred to as "computer vision" for short.

[0052] To make the spatial information of the objects in the sales area stored in the data structure accessible to humans, visualization software accesses the data structure and controls a visualization device, such as a screen or a virtual reality headset, according to the view of the sales area desired by the user. The visualization software can be processed locally on the data processing device and transmit its control data and / or content data to the respective visualization device, e.g., wired or wireless in the case of the screen, or preferably wireless in the case of the virtual reality headset, e.g., using the aforementioned radio technology. A screen of the navigation system can also function as a visualization device.

[0053] Subsequently, the location reference of the magnetic field detected by the magnetic field detection device is established by evaluating the recording made at the same location, which is discussed in detail below.

[0054] During this process, the known optical and / or optoelectronic parameters of the camera can be used to determine, for example, the distance between the camera device (or its optoelectronic imaging system) and an object in the image. Real-world dimensions can then be easily converted because the image usually contains a large number of objects (shelves, shelf bases, electronic display devices, etc.) for which the real dimensions are known. Knowing the dimensions of a real object, it is possible, for example, to determine a scale that indicates the real unit of measurement to which a pixel or pixel pitch in the digital image corresponds. In the digital image of a known object, only the number of pixels along an object edge needs to be determined (counted) and put in relation to the real dimensions of the object along this object edge.The lens equation can now be used to a good approximation, for example to determine the distance of the camera from the real object.

[0055] Since every image of a scene usually has a spatial perspective, a dynamic scale can also be generated for this perspective, which changes (to a good approximation linearly) along the perspective, i.e., along the imaged spatial depth. In any case, with the help of the respective image and taking into account the perspective distortions of known objects in the image, i.e., based on the geometric conditions derived from it, the precise position of the camera device in relation to the captured scene can be determined, both in reality and in the digital image. This location of the camera device corresponds to a good approximation of the location of the magnetic field detection device, since this moves with the camera device, and is stored in the digital image of the sales room together with the magnetic field determined for this location.

[0056] Since this process is carried out for all magnetic field recordings along the respective movement path, if there is a sufficiently high number of different movement paths in the sales area, which are not necessarily but preferably evenly distributed in the sales area, the digital magnetic field map of the sales room is obtained in summary, whereby the (recorded) magnetic field present at these locations is assigned to individual locations in the sales room.

[0057] The position of the magnetic field detection device can also be determined using a virtual camera that is placed in the virtual space and with which a recording is generated from its position with a defined orientation in its detection area. The virtual camera uses the same parameters for its optoelectronic detection system as the real camera device. The virtual camera is then moved in the virtual space and its orientation adjusted until the recording created with it has the same content as that of the real camera device. The position found in this way defines the location of the camera device with which the real scene was captured and is used to determine the location at which the magnetic field detection device carried out the magnetic field detection in real space.The detected magnetic field is thus recorded in the magnetic field map with this location reference. The purely image-based location determination process described here can be repeated for the numerous locations along the trajectory. Location determinations can be made step by step along the trajectory or a continuous location determination process can be performed. This can depend on the type of recordings along the trajectory and the available computing power. Furthermore, the scaling between real space and virtual space can be performed, as previously discussed, using the determined scale.

[0058] A navigation device used to determine its location and, based on this, for navigation in the sales area—i.e., for indoor navigation, where a satellite-based GPS navigation signal is generally unavailable—uses the digital magnetic field map to orient itself within the sales area. The navigation device itself records the magnetic field at its location (similar to a magnetic field detection device using an integrated magnetometer). The magnetic field recorded at its location is then compared with the magnetic fields stored in the magnetic field map until a match with one of the magnetic fields stored there is found with sufficient probability. The location stored in the magnetic field map for this detected magnetic field is then identified as the location of the navigation device.

[0059] Based on the location determined by the navigation device in the sales area, navigation to another location in the sales area can now be initiated. This could, for example, involve navigating to a specific product. To enable this, a magnetic field route from the current location to a destination is generated from the magnetic field map and provided to the navigation device for navigation to the destination.

[0060] The navigation device can be implemented, for example, by a smartphone or tablet computer (hereinafter referred to as the user device), running an application programmed for magnetic field-based navigation. These devices contain the magnetometer, whose acquisition data the application has access to. At the same time, the device can also access, for example, a digital shopping list containing the product to be searched for.

[0061] The location of the desired product is known to the data processing device according to the underlying planogram or, where applicable, realogram, and is also mapped in the virtual space, allowing the data processing device to determine the shortest route through the sales area. Since the data processing device also has access to the digital magnetic field map of the sales area, which is integrated into the virtual space, it provides a route description as a sequence of stored magnetic fields from the current location to the desired product.

[0062] In contrast to known navigation methods, no directions are provided in the sense of visually perceptible directions for the user of the user device, which they can visually orient themselves by in order to follow the path provided therein. In this case, rather, a "magnetic field route" is provided, i.e., the sequence of magnetic fields to be traversed in the sales area in order to reach the product. This sequence of magnetic fields to be traversed represents, figuratively speaking, the "series of magnetic waypoints" that the user must follow to reach the destination. In this context, it can also be mentioned that transitions between neighboring "waypoints," i.e., from one magnetic field of one location to the next magnetic field of the next location, can also be smoothed or interpolated to depict a continuous course.

[0063] This magnetic field route allows the user device, using its magnetometer, to determine whether the user is on the correct course toward the product. If the user device detects a deviation, it can inform the user either acoustically (movement instructions in the form of, for example, voice prompts, tones, or noises whose interpretation is known to the user) or tactilely (movement instructions in the form of, for example, vibrations, etc., whose interpretation is known to the user) or communicate corrective measures in the aforementioned instructional format (acoustic / tactile).Since, on the one hand, the magnetic field is detected very precisely and linearly along the movement path of the position-variable magnetic field detection device, but on the other hand, complete detection of every point in the sales area designated for pedestrian traffic is not necessary, and ultimately, every movement of a person—and therefore also of the user device carried with them—is subject to a certain dynamic and peculiarity, it has proven advantageous to take measures to avoid inundating the user with movement instructions to correct their movement. Therefore, the user device can be programmed to permit deviations from the magnetic field route to a certain, acceptable extent, provided these deviations correspond to the user's typical movement behavior and do not lead to a sustained departure from the magnetic field route.The magnetic field route itself can also be designed wide enough to accommodate typical user movement patterns. The magnetic field route can also cover an entire shelf aisle, for example. The provision of movement instructions can also be delayed until a deviation from the magnetic field route is detected, allowing the user a certain amount of freedom of movement. Only when the user deviates from the magnetic field route for longer than pre-programmed will they be confronted with this circumstance.

[0064] Once the user has arrived at the destination, he or she can still be informed of where to orient themselves, as this is also determined from the orientation of the user device moving with him or her (detected via the user device's digital compass) on the one hand and from the known position of the product in relation to the end of the magnetic field route on the other, in order to be able to reliably visually detect the product in question, or in other words, to be able to see it.

[0065] Below, aspects of the efficient design of the magnetic field map that are closely linked to the position-variable camera system are discussed. It should also be noted at this point that the magnetic field detection device can either be an integrated component of the camera system or be moved along with it as a separate device. If the magnetic field detection device is integrated into the camera system, the statements made regarding the camera system's mounting and / or alignment also apply to the magnetic field detection device, unless otherwise stated.

[0066] According to the introductory disclosure of this patent application, the positionally variable camera device can be designed as a self-propelled device, e.g., as a self-propelled robot. Preferably, the surroundings of the movement path are captured using a remotely moved positionally variable camera device. This allows for a significantly more cost-effective, simpler, and flexible capture of the basic structure of the path area.

[0067] An externally moved camera device is not a camera attached to a self-driving robot that moves within the sales area according to the robot's logic or a trajectory determined by the robot's remote control. Rather, the external movement is caused by the action of a person, with the person either moving the position-variable camera directly through the sales area or indirectly because the position-variable camera device is attached to an object, such as a shopping cart, that is indirectly moved by the person.

[0068] According to a first embodiment, the externally moved, location-variable camera device can be a 360° camera with which an all-round recording of the surroundings of the movement path is carried out. This 360° camera can be attached to a shopping cart, e.g. to an upwardly projecting pole, preferably at the end of the pole, in order to be positioned high enough so that the person externally moving the shopping cart and thus the camera is not too disruptive or too dominant in the 360° camera recording. However, it is particularly preferred that the 360° camera is attached to the body or clothing of a person. The camera is preferably positioned on the head or shoulder in order to obtain the most unobstructed 360° field of view possible. This type of external movement enables the camera to be used to record the surroundings of its movement path whenever the person moves through the sales area.Since this is a 360° camera, which, as its name suggests, is designed for 360° imaging of the surroundings, it is irrelevant in which direction the person is moving within the sales area or where they are facing, whether standing or moving. The 360° camera can continuously capture the surroundings—except for the detection area shadowed by the person—or only capture it when a built-in motion sensor detects movement. Consequently, it can be assumed that the 360° camera is also moving along a trajectory.

[0069] According to a first embodiment, the surroundings of the movement path can be captured using a location-variable camera device mounted on a shopping cart. This embodiment also involves an externally moved camera device, as the shopping cart is moved by staff moving around the sales area or by customers moving through the sales area. As mentioned, a 360° camera mounted on the end of a pole can be used for this purpose. However, experience has shown that the pole is often used improperly, for example, to hang up clothes, which completely covers the 360° camera and thus renders it inoperable. Optionally, the length of the pole can be selected so that this cannot occur, although this may raise aesthetic criticism.Such a solution is also prone to damage, as people often tend to move the shopping cart by grasping the pole, even though the pole is only intended to carry a very lightweight camera device and, to fulfill this purpose, must be relatively delicate and fragile. In any case, making the pole safe for use involves considerable additional effort.

[0070] It has therefore proven particularly advantageous to capture the area around the path of movement from a shopping trolley basket. In this position, the mobile camera is particularly protected. From this relatively low position, it is also easy to see into the various shelves, as the shelves are usually installed with a slight downward slope. In this context, it has also proven particularly advantageous to capture the area around the path of movement through openings in the shopping trolley basket or its wall, in particular between the bars of the basket. In this case, the camera equipment is located in a secure position. It cannot be damaged there because the wall of the basket or its wall, which is designed for maximum load, is protected from sunlight.The basket's bars, which are usually made of metal, provide the necessary protection against improper handling by the person pushing the shopping cart, as well as against collisions with hard objects. Thus, the existing mechanical structure of the basket is used in two ways: firstly, for protection and secondly, for supporting the camera equipment.

[0071] To avoid the camera device's detection area being obscured by the person moving the shopping cart, the camera device is not attached to the section of the basket facing the person pushing the shopping cart. The camera device can, for example, be attached to the sides of the basket and from there record the area around the path of movement. However, if attached to one of the sides, the camera device can only record the relevant lateral area, from where the detection area can be quite limited due to the sometimes relative proximity to shelves or other objects positioned along a shelf aisle. The area around the path of movement is therefore preferably recorded from a position at the front of the shopping cart. This is where the camera device usually has the widest detection area and can therefore be used to record large areas.The camera's detection range is also not affected by objects in the basket.

[0072] Particularly preferably, the position-variable camera device for capturing the surroundings of the movement path has at least one capturing stage with a stereo camera. The capturing stage is understood to mean the optics and electronics required at least for generating raw video and / or still image data representing the captured scene, which is generally known to those skilled in the art. The stereo camera allows stereoscopic recording of the surroundings, thereby facilitating the evaluation of three-dimensional structures by image processing software, such as computer vision. Preferably, the position-variable camera device has at least a first and a second, preferably also a third, capturing stage, each of the capturing stages capturing an individual spatial sector of the surroundings of the movement path.This means that each of the detection stages has its own optical detection system, which is individually aligned according to the spatial sector to be detected.

[0073] It has proven particularly advantageous that the position-variable camera system has three detection levels at the front of the shopping cart. Relative to the front of the shopping cart, the first detection level covers a first spatial sector diagonally to the left, the second detection level covers a second spatial sector diagonally to the right, and the third detection level covers a third spatial sector centrally. This allows the detection and thus the provision of information to be individually optimized by recording each detection level. The laterally oriented detection levels can be optimized for the focused detection of the shelf contents and therefore do not require an extremely deep detection range, as they are usually moved relatively close to the shelves.In contrast, a fairly wide detection range can be set for the centrally forward-oriented detection level in order to be able to "see" as deep as possible into the shelf aisle.

[0074] In this context, it has also proven particularly advantageous to position the first detection level, which detects diagonally to the left, on the right front side of the shopping cart, and the second detection level, which detects diagonally to the right, on the left front side of the shopping cart. This crossover of the detection directions at the front of the shopping cart ensures that the distance between the optics of the respective detection level and the structures or objects to be detected is maximized, resulting in the widest possible detection range for each detection level.

[0075] In order to obtain a coherent capture of the surroundings of the variable-position camera system along the front of the shopping cart, it has proven particularly advantageous if two of the capture stages are configured such that the spatial sectors captured by them overlap at least slightly. For example, the capture area oriented diagonally to the left can slightly overlap with the capture area oriented centrally. Likewise, the capture area oriented diagonally to the right can slightly overlap with the capture area oriented centrally. These slight overlaps enable computer vision to identify the connection points or overlapping areas in the respective image and to process the images coherently.

[0076] If the camera system uses multiple detection stages that are spatially separated, it may be sufficient to provide only a single magnetic field detection device that moves with the camera system. In this case, its position can be assigned to exactly one of the detection stages and determined accordingly. However, it may also be advantageous to position a single magnetic field detection device at a central position between the detection stages of the camera system.

[0077] Preferably, the number of magnetic field detection devices corresponds to the number of detection levels of the location-variable camera device and each magnetic field detection device is positioned locally at exactly one of the detection levels.

[0078] Thus, multiple magnetic field detection stages can be provided, in particular as many as the number of detection stages of the camera device. Preferably, each of the magnetic field detection stages is assigned to exactly one of the detection stages of the camera device and is positioned in its immediate vicinity or integrated into it. This has the advantage that, with a single movement of the shopping cart, multiple magnetic field detection stages are simultaneously moved along individual movement paths for the purpose of detecting the magnetic fields present there. This results in multi-track magnetic field detection along the path of the shopping cart.

[0079] The location-variable camera device can be designed as a component of the shopping cart, i.e., already integrated into the shopping cart at the factory. However, the location-variable camera device is particularly preferably a retrofit kit that can be attached using a fastening mechanism adapted to the respective type of shopping cart. This has the advantage that millions of conventional shopping carts in use can be upgraded in order to deploy the invention across the board with the lowest possible investment. The location-variable camera device is particularly preferably installed in a flat, plate-like housing that is attached from within the shopping cart basket to the front of the shopping cart using the fastening mechanism. The fastening mechanism holds the location-variable camera device to the structure of the basket, e.g.by a mounting plate that is screwed to the plate-shaped housing from outside the basket, so that part of the basket structure is clamped between the mounting plate and the housing. A plug-in mechanism can also be used as a mounting mechanism, allowing easy attachment to the inside of the basket wall. The optics of the respective detection stage are positioned, or can be variably positioned, according to the type of shopping cart in such a way that they can "see through" the basket structure through the openings of the basket without obstruction, meaning that the beam path of the respective optics is as unaffected as possible by the basket.

[0080] According to a further embodiment, the retrofit kit can also be configured so that the respective optics look over the top edge of the shopping cart. This creates an even more universally applicable retrofit kit in which the positions of the respective optics are decoupled from the existing structure of the basket. Such a retrofit kit can also be attached independently of the position of the respective optics below the top edge of the basket. The same applies, with appropriate adaptations, to a retrofit kit designed for attachment to the underside of the front edge of the basket, from where the optics of the respective detection level can be positioned unhindered by the structure of the basket.

[0081] In summary, it should be noted that the system described above as well as the method are characterized by a number of features, which are pointed out below.

[0082] The measures discussed allow for the fully automated generation of a digital map of the sales area. Such a digital map is also known in technical jargon as a vector floor map and can depict the sales area in two or three dimensions, in this case including the magnetic field map, which forms the basis for magnetic field-based navigation in the sales area. The end result is a digital map of the sales area that records the relationship between the respective detected magnetic field and the location in the sales area where the magnetic field was detected.

[0083] In general, it should be noted at this point that the data processing device can also be programmed to control the ESLs to display product and / or price information. Status information can also be received and processed from the ESLs. Likewise, an LED that may be available on the ESL can be controlled. The same communication network can also be used for communication with the camera devices. However, a separate communication network can also be used for communication with the ESLs. The measures required in connection with the operation and management of the ESLs (devices and methods, hardware and software) are, moreover, sufficiently familiar to those skilled in the art.

[0084] Finally, it should be generally mentioned that the electronic devices and equipment discussed above naturally incorporate electronics. The electronics can be discrete, integrated, or a combination of both. Microcomputers, microcontrollers, and Application Specific Integrated Circuits (ASICs), possibly in combination with analog or digital electronic peripherals, can also be used. Many of the device functionalities mentioned above are implemented—possibly in conjunction with hardware components—using software running on an electronic processor. Devices designed for radio communication typically incorporate an antenna configuration for transmitting and receiving radio signals, as well as a modulator and / or demodulator, as part of a transceiver module.The electronic devices can also have an internal electrical power supply, which can be implemented, for example, with a replaceable or rechargeable battery. The devices can also be powered wired, either via an external power supply or via "Power over LAN." A wireless power supply can also be provided via "Power over WiFi."

[0085] Battery-operated electronic display units are preferably equipped with energy-saving electrophoretic screens.

[0086] These and other aspects of the invention are apparent from the figures discussed below.

[0087] Short character description

[0088] The invention will be explained in more detail below with reference to exemplary embodiments, to which, however, the invention is not limited. It shows schematically:

[0089] Fig. 1 shows a section of a basket of a shopping trolley on which a position-variable camera device with integrated magnetic field detection devices is mounted on the front inside the basket;

[0090] Fig. 2 shows a block diagram of the electronics of the position-variable camera device with three detection stages and the magnetic field detection devices associated with these detection stages; Fig. 3 shows the detection ranges of the three detection stages of the position-variable camera device;

[0091] Fig. 4 the three detection areas in the context of a shelf goose;

[0092] Fig. 5A - 5C realistic still images of shelves and goods positioned on them as well as electronic display devices along the shelf aisle using the three detection levels;

[0093] Fig. 6 a sales area in which three shopping carts with variable-position camera devices are moving.

[0094] Description of the embodiments

[0095] Figure 1 shows a basket 1 of a conventional shopping cart 2, which is in use millions of times over. On the front of the shopping cart 2, on the inside of the basket 1, there is a variable-position camera device 3 which has three magnetic field detection devices (magnetometers) 35 integrated into it. The basket 1 is formed by metal rods, which are referred to below as rods 4. The variable-position camera device 3 is a retrofit kit for the shopping cart 2. The variable-position camera device 3 is attached to the basket 1 by means of two fastening plates 5 provided outside the basket 1, which are screwed to a plate-shaped housing 6 of the variable-position camera device 3 by means of two screws 7 (which are only marked with reference numerals on the left-hand fastening plate 4).The position-variable camera device 3 has three stereo image acquisition stages 8, 9, and 10, hereinafter referred to as acquisition stages 8, 9, and 10. Their respective stereo optics 11, 12, and 13 (see also reference numerals 11, 12, and 13 in Figure 2) intended for image acquisition, or the individual image acquisition area realized by the respective optics, are essentially unobstructed by the rods 4 of the basket 1. The respective stereo optics thus "look" through, figuratively speaking, between the rods. It should be noted that the stereo optics of the middle acquisition stage 10 are aligned horizontally, whereas the stereo optics of the two outer acquisition stages 8 and 9 are aligned vertically, which facilitates stereo resolution in the respective orientation.

[0096] To enable detection unhindered by the bars 4 of the basket 1, the first stereo optic 11 of the first detection stage 8 is attached to a first positioning arm 8A that can be flexibly pulled out of the central housing 6 or pushed into the central housing 6, and can thus be variably positioned on the front of the shopping cart 2, taking into account the bars 4 or a gap opening therebetween. The same applies to the second stereo optic 12 of the second detection stage 9, which is attached to a second positioning arm 9A that can be flexibly pulled out of the central housing 6 or pushed into the central housing 6.

[0097] A first image capture area (reference numeral 20 in Figure 3) of the first capture stage 8 is oriented diagonally ahead to the left, a second image capture area (reference numeral 21 in Figure 3) of the second capture stage 9 is oriented diagonally ahead to the right, and a third image capture area (reference numeral 22 in Figure 3) of the third capture stage 10 is oriented centrally ahead. The three image capture areas, which actually have a spatial extent, thus essentially corresponding to spatial sectors, hereinafter referred to as capture areas 20, 21, and 22, are visualized, as mentioned, in Figures 3 and following.

[0098] Figure 2 uses a block diagram to show functional groups of the position-variable camera device 3. The three acquisition stages 8, 9, and 10 indicate the respective stereo optics 11, 12, and 13, as well as their orientation discussed in the previous paragraph. Acquisition stages 8, 9, and 10 are digital stereo cameras that transmit the image data BD from their recordings via a bus 14 designed to transmit digital data and / or control signals to a processing device 15 implemented with the aid of a microcontroller and the software executed on it. With the aid of the processing device 15, (pre-)processing of the image data and / or evaluations of the image data BD are performed, and communication with external devices, such as an access point or a network component of an IoT network (IoT stands for "Internet of Things"), is established for transmitting the, if necessary,preprocessed image data BD or for transmitting the evaluation results obtained by the evaluation. For physical communication with the external device, the camera device 3 has a first radio communication stage 16, which has the necessary active and passive electronic components (generally referred to as transceivers), which is merely indicated by an antenna configuration 17.

[0099] The mobile camera device 3 further comprises a power supply 18 for its electrical supply, which is implemented using a rechargeable battery 19 and is designed to provide a supply voltage VCC relative to a reference potential GND. The power supply 18 can utilize various technologies to charge the battery 19, such as Power over WiFi for energy transmission via WiFi signals or a photovoltaic panel integrated into its housing 6 for "energy harvesting" from ambient light, etc.

[0100] The position-variable camera device 3 further comprises the respective magnetic field detection device 35, symbolized here as a compass, integrated into the respective detection levels 8, 9, and 10. With the help of the magnetic field detection devices 35, the magnetic field is detected at the respective detection location, i.e., with respect to the stationary shopping cart 2, at three different locations where the respective detection levels 8, 9, or 19 are also located. If the shopping cart 2 is moved, the magnetic field is detected along a movement path of the respective detection level 8, 9, or 10, which is also followed by the magnetic field detection level 35 integrated there. Thus, the magnetic field can be detected de facto simultaneously along the three movement paths.At the same time, the image acquisition takes place with the three acquisition levels 8, 9 and 10 and the magnetic field acquired at the respective location is transmitted together with the image data BD of the respective acquisition levels 8, 9, 10 via the first radio communication level 16, as explained in the general description.

[0101] Figure 3 shows the shopping cart 2 with the location-variable camera device 3. Furthermore, the first detection area 20 of the first detection level 8, the second detection area 21 of the second detection level 9, and the third detection area 22 of the third detection level 10 are indicated here, starting from the front of the shopping cart 2 or the three detection levels 8, 9, and 10 positioned there. Also clearly visible here is the overlap of at least the edges of the detection areas 20 with 22 and 20 with 21 in the immediate vicinity of the shopping cart 2, which facilitates the assembly of the images created using the respective detection levels 8 to 9 into a kind of "panoramic image" of the scene in front of the shopping cart 2. Regarding the positions of the three detection levels 8, 9, and 10, reference is made to Figure 1.

[0102] In Figure 4, the shopping cart 2 is shown positioned between two shelves 23, as is typically the case in a sales area 27 of a retailer, e.g., operating a supermarket, where the shelves 23 flank a shelf aisle. The shopping cart 2 is typically moved there by a person (customer), as is the location-variable camera device 3 mounted on the shopping cart 2. Individual items 25 are stored on the shelves 23, or more precisely on shelves or shelf compartments 24 of the shelves 23; however, for reasons of clarity, not all of these items are provided with reference symbols.It can be clearly seen here that the first detection area 20 oriented diagonally to the left and the second detection area 21 oriented diagonally to the right enable an almost frontal view into the shelves 23 located there down to the shelf floors 24 and thus enable a very detailed visual recording of the objects and structures there, whereas the third detection area 22 oriented centrally to the front enables a far-reaching overview of the arrangement of the shelves 23 along the shelf aisle as well as the course of the shelf aisle in front of the shopping cart 2.

[0103] During the path of the shopping cart 2, a three-lane detection of the magnetic field between the shelves 23 takes place, as described in Figure 2.

[0104] Figures 5A to 5C visualize the images, i.e. the visual recording of the structures along a shelf aisle using the three previously discussed recording stages 8, 9 and 10. Figure 5A shows the arrangement of the shelves 23 on the left side of the shelf aisle, i.e. starting just in front of the shopping cart 2, as recorded with the help of the first recording stage 8. Figure 5C also shows the arrangement of the shelves 23 on the right side of the shelf aisle, i.e. starting just in front of the shopping cart 2, as recorded with the help of the second recording stage 9. Figure 5B shows the course of the lateral shelves 23 extending in front of the shopping cart 2 along the shelf aisle up to a transverse shelf 23, where the shelf aisle turns to the right in front of this transverse shelf 23.It can be clearly seen that two adjacent images of shelves 23, i.e., the pairs of images shown in Figures 5A and 5B as well as in Figures 5B and 5C, show common areas that allow the individual images shown in Figures 5A, 5B, and 5C to be linked. Thus, with the help of the three detection levels 8, 9, and 10, the overall situation in front of shopping cart 2 is de facto spatially detected, namely between the right and left detection edges as well as between the upper and lower detection edges, precisely within the available detection areas 20 to 22.The captured digital images show not only the shelves 23 but also the shelf bases 24, which are only labeled on the outer edges of Figures 5A and 5C, the goods 25 presented on the shelf bases 24, which are labeled only once per Figures 5A to 5C, as well as electronic display devices 26, typically mounted on shelf rails installed there (not explicitly labeled with a reference symbol because they are known per se), on the front edge of the shelves, referred to in technical jargon as "electronic shelf labels", or ESLs 26 for short, which, for reasons of clarity, are only labeled a few times in the lower area of ​​the respective Figures 5A to 5C. However, these ESLs 26 are located for all goods 25 corresponding to the respective goods 25 at the corresponding positions on the shelf rails, which has not been fully visualized in order not to overload Figures 5A, 5B, and 5C.

[0105] The image data BD generated by acquisition stages 8, 9, and 10, together with the values ​​of the detected magnetic field, are transmitted by the variable-position camera device 3 via its radio communication stage 16 for further processing, which will be discussed in more detail below. It should be noted, however, that depending on the external movement of the variable-position camera device 3, different image contents are continually generated, which are transmitted in essentially a continuous sequence via the radio communication stage 16. The same applies to the three-track magnetic field acquisition, which essentially runs synchronously with the image acquisition, with the respective magnetic field values ​​being transmitted synchronously with the image data transmission in order to ensure their digital connection and subsequently be able to correctly assign them to the locations of their acquisition.

[0106] What was discussed for one shopping cart 2 naturally also applies to the other shopping carts 2 that are equipped with the location-variable camera device 3 and are moved through the sales area 26, as shown in Figure 6. In this configuration, essentially (depending on network latency), the zone of the sales area 26 in front of the respective shopping cart 2 is simultaneously imaged using the respective location-variable camera device 3, and the image data BD generated therefrom is output together with the magnetic field values.The image data BD continuously generated during the external movement of the various location-variable camera devices 3, together with recorded magnetic field values, are transmitted via a wireless network (of which only a single access point 28 is visualized for reasons of simplification, but in reality several are installed throughout the sales area). From the access point 28, via a wired I_AN network (LAN stands for "Local Area Network"), they are transmitted to a data processing device 29, which is formed by a powerful server with application-specific software for image processing, where they are assembled into a three-dimensional overall view of the sales area 27. The software is also programmed to generate the digital magnetic field map mentioned in the general description using the measures discussed in the general description.

[0107] As soon as the last area of ​​the sales area 27 has been captured using the location-variable camera device(s) 3, a complete digital image of the sales area with all its structural elements or objects (shelves, shelf boards, goods, ELS, etc.) can be created, which is referred to in the applicant's technical jargon as a "master 3D location map" because this digital data structure stores the entirety of the objects and their three-dimensional location in the sales area 27. This master 3D location map is essentially a static digital image of the sales area, which only exhibits relatively unspectacular dynamics insofar as a further external movement of one of the shopping carts 2 is used to update the master 3D location map along the respective movement path.

[0108] Repeatedly driving through the same zones of the sales area can be used to obtain more accurate visual representations of the sales area, thus modeling the virtual space more precisely or ensuring updates to the virtual space. The same applies to repeated recordings of the local magnetic field in this area. Driving through the area multiple times increases the number of magnetic field measurements available for this area, i.e., their density, which contributes to more accurate location determination during navigation.

[0109] Equipped with a PDA containing a navigation device for magnetic field-based navigation, a customer's shopping list, for example, can be transmitted to supermarket staff, who in this case act as store pickers. The store picker moves through the sales area under the guidance of the navigation device—as discussed in the general part of the description—and is guided to the items 25 contained in the list with the aid of the magnetic field map, from which the respective magnetic field route was generated. This process can take place entirely without using the PDA screen, because the PDA provides all information regarding navigation as well as the product to be searched for acoustically. This makes it easier for the store picker to handle the items, as they have both hands free, thus speeding up their workflow. In addition, the lifespan of the PDA battery is extended or even eliminated.optimized because the screen typically consumes the most power. The screen can be completely turned off during the process described here, because the store picker's confirmation that they have processed the current list item can also be signaled by a movement of the PDA, which the PDA can detect using its electronics.

[0110] Finally, it should be noted once again that the figure described in detail above is only one exemplary embodiment, which can be modified in a variety of ways by a person skilled in the art without departing from the scope of the invention. For the sake of completeness, it should also be noted that the use of the indefinite articles "a" or "an" does not exclude the possibility that the relevant features may be present multiple times.

Claims

Claims 1. Method (30) for creating a navigation basis for navigation in a sales area (27), which comprises the following method steps, namely: - detecting the magnetic field along a movement path in the sales area by means of at least one location-variable magnetic field detection device which is moved along the movement path in the sales area, and - a computerized creation of a location reference in the sales room for the magnetic field recorded at the respective location along the movement path, and - storing the recorded magnetic field and its location in the sales area in the form of a digital magnetic field map.

2. Method (30) according to claim 1, wherein the location reference is established with the aid of a location-variable camera device (3), which camera device (3) is moved along with the magnetic field detection device and creates a digital recording of the surroundings of the movement path of the magnetic field detection device in the sales area (27).

3. Method (30) according to claim 2, wherein the magnetic field detected at the respective location of the movement path and the recording made at this location are digitally linked to one another.

4. The method according to claim 3, wherein the combining of the detected magnetic field and the created image takes place in a combination device which has the magnetic field detection device and the camera device.

5. The method according to claim 4, wherein, in the case of a design of the camera device as a still image camera designed to generate still images, the respective still image is provided together with the magnetic field detected corresponding in time to the still image.

6. The method according to claim 4, wherein, in the case of a design of the camera device as a video camera which is designed to generate a video recording structured in video frames, the respective frame of the video recording is provided together with the magnetic field detected in a temporally corresponding manner to the respective frame of the video recording.

7. Method (30) according to one of the preceding claims, wherein the magnetic field is detected several times along at least partially different movement paths in the sales area.

8. Method (30) according to one of the preceding claims 2 to 7, wherein a generation (32) of a digital image of the sales area (27) is carried out by processing the surroundings of the movement path in the sales area (27) captured with the aid of the at least one location-variable camera device (35; 40) with the aid of image processing software, in particular with the aid of software measures referred to in technical jargon as computer vision, wherein as a result of the processing a virtual space is created as a digital image of the sales area.

9. Method (30) according to claim 8, wherein the location reference of the magnetic field detected by the magnetic field detection device is established by evaluating the recording made at the same location.

10. Method (30) according to one of the preceding claims 2 to 9, wherein the detection of the surroundings of the movement path is carried out with the aid of an externally moved, location-variable camera device (3).

11. Method (30) according to one of claims 2 to 9, wherein the location-variable camera device (3) is a 360° camera, in particular a 360° camera attached to the body or clothing of a person, with which an all-round detection of their surroundings of the movement path takes place.

12. Method (30) according to one of claims 10 to 11, wherein the Capturing the environment of the movement path with the location-variable Camera device (3) which is mounted on a shopping cart (2).

13. Method (30) according to claim 12, wherein the detection of the surroundings of the movement path takes place from a basket (1) of the shopping cart (2).

14. A navigation method for navigating in a sales area, comprising the following procedural steps, namely: - detecting the magnetic field at the location of a navigation device, and - determining the location of the navigation device in the sales area with the help of a digital magnetic field map in which the magnetic fields present at locations in the sales area are stored.

15. Navigation method according to claim 20, wherein a magnetic field route from the current location to a destination is generated from the magnetic field map and is provided to the navigation device for navigation to the destination.

Images