System and method for controlling the switching between radio signal access points

Abstract

Method for controlling the switching between radio signal access points (4) in a radio network with multiple radio signal access points (4) in a working environment for autonomous vehicles (2), comprising the steps of: detecting a local distribution of a radio signal strength and / or a coverage area of ​​a respective radio signal access point (4) by an autonomous vehicle (2), transmitting the detected data from the autonomous vehicle (2) to a networked computer (5), analyzing the detected data by the computer (5) and / or creating a zone map by the computer (5) for the radio signal access points (4) in the working environment, providing the analyzed data and / or the zone map for route planning of autonomous vehicles (2) in the working environment. The disadvantages of the prior art are thereby overcome.

Description

[0001] The invention relates to a system for controlling the switching between radio signal access points in a radio network with multiple radio signal access points, in particular for autonomous vehicles or mobile robots such as a driverless transport system. The invention also relates to a corresponding method, which can improve radio reception and thus improve the runtime of autonomous vehicles in a work environment.

[0002] Manufacturing and distribution companies, in particular, require short lead times and high flexibility in the supply and / or distribution of components or other items. Automated guided vehicle systems are increasingly being used for automated internal material flow, which includes targeted scheduling of goods. Automated guided vehicle systems comprise transport systems with automatically controlled vehicles or mobile robots, primarily used for material transport. These systems enable targeted automation of transport processes.

[0003] Mobile load carriers are often moved in a predetermined or guided manner by autonomous mobile robots to transport material from a warehouse to a destination in a targeted manner and over the shortest possible route. These autonomous vehicles or mobile robots are usually deployed along predetermined paths that are repeatedly traveled. The mobile robots are connected to a wireless network, such as Wi-Fi, to receive information within their work environment, such as the route, orders, approved waypoints, and / or actions to be performed. The work environment features a broad Wi-Fi network infrastructure with multiple access points to ensure a consistently good signal strength.

[0004] The Wi-Fi coverage of the various access points typically overlaps in the work environment. Therefore, the vehicle does not know when to switch to a specific access point to maintain at least a consistent or even the best Wi-Fi signal strength. If the vehicles do not know when to switch to a specific access point to maintain the desired or required Wi-Fi signal strength, the vehicle must initiate a scan and attempt to find the best access point to connect to, and then switch to the new access point. If scanning the Wi-Fi access point takes too long, the vehicle typically has to wait at the last waypoint to receive further navigation instructions. This leads to traffic congestion in the work environment. This scan must typically be performed every time the vehicles determine that the Wi-Fi signal is too weak.In particular, if the vehicle switches to an incorrect access point at an intersection or traffic junction, it must immediately switch to another Wi-Fi access point, which causes particularly large delays and makes the running time of an autonomous vehicle or mobile robot unpredictably long.

[0005] Based on this, the object of the invention is to at least partially alleviate the problems described with reference to the prior art and, in particular, to improve existing driverless transport systems or autonomous robots and / or to reduce their running times in their working environment.

[0006] These objects are achieved by the subject matter of the independent claims. Preferred developments can be found in the subclaims. The features specified in the claims can be combined with each other and / or with features of the description in any technologically expedient manner. The description, particularly in conjunction with the figures, explains the invention and provides further embodiments.

[0007] A system with at least one autonomous vehicle equipped with a radio modem contributes to this. The system further comprises a radio network with multiple radio signal access points in the working environment of the autonomous vehicle. The system is configured to use the autonomous vehicle to record a local distribution of a radio signal strength and / or a coverage area of ​​a respective radio signal access point and to send the recorded data from the autonomous vehicle to a networked computer. The recorded data is analyzed by the computer and / or mapped in the form of a zone map for the radio signal access points in the working environment. The system is further configured to provide the analyzed data and / or the zone map for route planning of autonomous vehicles in the working environment.

[0008] In particular, the system enables significantly more efficient use of autonomous vehicles, such as driverless transport systems, particularly by improving radio reception and thus improving the runtime of autonomous vehicles in a work environment. To reduce or avoid existing traffic congestion, autonomous vehicles are deployed. These vehicles can first scan the various access points within a production environment during the mapping phase and transmit this information specifically to a Wi-Fi server. The Wi-Fi server performs the necessary analyses and creates a zone layout of the access points for the entire production facility.This zone layout of the access points is primarily passed on to the other autonomous vehicles, which use this access point information as additional data for each individual waypoint, which is then later sent to the vehicles as navigation instructions.

[0009] An autonomous vehicle can comprise a mobile robot or a driverless vehicle controlled by programmed electronics, such as an automated guided vehicle (AGV), an order-picking system, or even a vacuum robot. Autonomous vehicles can also be semi-autonomous, where the vehicles only perform part of their tasks independently. For example, a movement path can be largely defined by external environmental devices or floor elements, and the autonomous vehicle simply avoids obstacles on the way to the specified destination based on sensors.

[0010] In the case of the widely used WLAN, wireless signal access points typically include access points or routers.

[0011] The recording of the local distribution of a radio signal strength and / or the coverage area of ​​a respective radio signal access point can be carried out, in particular, through systematic journeys of the autonomous vehicle in a specific, preferably equidistant or homogeneous grid, possibly following a predefined plan / pattern or routine. Other journey patterns, mapping only during normal vehicle operation, or even a density of data points adapted to the conditions are also possible.

[0012] The zone map for route planning typically includes a 2D map on which the signal strength of the wireless network is recorded for discrete points. Instead of or in addition to signal strength, other, particularly physical, variables can also be mapped, such as the signal-to-noise ratio and / or a quantification of signal quality tailored to the application.

[0013] Route planning is typically based on algorithms that calculate the most collision-free movement possible for autonomous vehicles along mostly predefined paths.

[0014] In particular, the analyzed data and / or the zone map include locations in the working environment where the autonomous vehicle—especially during normal operation—should switch from a first radio signal access point to a second, neighboring radio signal access point. Locations where the switch is to occur can be (alternatively or cumulatively) boundary lines and / or boundary areas between the radio signal access points. More complex decision logic is possible, which, for example, considers the time required to switch the radio signal access point and / or incorporates other conditions (possibly with a specific weighting).

[0015] In a particular embodiment, the computer comprises a server, specifically a WLAN server. This allows the autonomous vehicle to easily transmit the acquired data, and further analysis of the data can be outsourced from the autonomous vehicle. The acquired data can then also be easily made available to other components in the network. Preferably, the computer is wirelessly connected to the autonomous vehicle, in particular also to the wireless network. This eliminates the need for sometimes cumbersome cabling for data exchange.

[0016] Using information about the wireless network infrastructure recorded during area mapping, along with a typically available route planning algorithm, improves switching to the correct wireless access point. It also avoids or prevents switching to the wrong access point and / or driving for too long in weak Wi-Fi conditions. This improves the traffic situation in the entire area because the robot does not stop due to weak wireless signal strength and / or because the monitoring system (fleet management system) receives delayed information about the robot's status (e.g., position).

[0017] During the mapping phase, a vehicle first scans the various access points within a production environment and preferably forwards this information to a WLAN server (or an application running on a central server that receives and processes the WLAN information). In one embodiment, the WLAN server can perform the necessary analyses and creates a zone layout of the access points, for example, for an entire production facility. This zone layout of the access points is used as input for the other autonomous vehicles, which can use this access point information as additional data for each individual waypoint, which is then later sent to the vehicles as navigation tasks.

[0018] Specifically, the wireless network is a Wi-Fi network and / or a ZigBee network and / or a Z-Wave network. These local wireless standards are particularly well-suited for local networks, although local and technical requirements must be considered when selecting a specific wireless standard.

[0019] The positioning module with its backstop and coupling mechanism allows for significantly more efficient use of a driverless transport system.

[0020] According to a further aspect, a method for controlling the switching between radio signal access points in a radio network with multiple radio signal access points in a working environment for autonomous vehicles is proposed, comprising at least the following steps: a. Detection of a local distribution of a radio signal strength and / or of a coverage area of ​​a respective radio signal access point by an autonomous vehicle, b. Transfer of the collected data from the autonomous vehicle to a networked computer, c. Analysis of the collected data by the computer and / or creation of a zone map by the computer for the radio signal access points in the work environment, d. Providing the analyzed data and / or the zone map for route planning of autonomous vehicles in the work environment.

[0021] Preferably, the method comprises determining location areas in the working environment based on the analyzed data and / or the zone maps at which the autonomous vehicle is to switch from a first radio signal access point to a second, adjacent radio signal access point.

[0022] In step a., the local distribution can be recorded using sensors on / in the autonomous vehicle and / or a radio modem located there. It is possible for several autonomous vehicles to interact with each other in step a. or contribute part of the data to record the local distribution. Data from at least one autonomous vehicle can also provide "updates" at different times, so that the knowledge or information about the distribution can be continuously adapted if necessary.

[0023] The transmission of the recorded data from the autonomous vehicle to a networked computer according to step b. is preferably carried out wirelessly using the wireless modem.

[0024] Thus, according to step c, the acquired data is analyzed by or in the computer and / or a zone map is created by the computer for the radio signal access points in the work environment. Consequently, an analysis unit and, if applicable, a storage unit for the data and / or the analysis results and / or the maps can be provided on the computer. The computer can have a communications module for sending and / or receiving data or can interact with such a module (possibly an external one).

[0025] The computer can provide the analyzed data and / or zone map, in particular to the at least one autonomous vehicle, for route planning of the autonomous vehicle in the working environment. This provision can also be made wirelessly.

[0026] The features mentioned regarding the operation or design of the system can also be used to characterize the method, and vice versa. In particular, the method can be implemented with the proposed system, or the system can be configured to carry out the proposed method. The system can, in particular, comprise means configured to enable the system to carry out the proposed method.

[0027] The invention and the technical environment are explained in more detail below with reference to figures, without these explanations limiting the invention itself. Unless explicitly excluded below, partial aspects or individual features shown in the figures may also be combined with each other and / or with the features of the claims or the preceding description. Where components in different figures are provided with the same reference numerals, their descriptions apply mutatis mutandis to all these components, unless explicitly stated otherwise. The figures schematically show: Fig. 1 a representation of a system according to the invention with additionally identified possible movement paths, Fig. 2 a representation of a movement sequence of an autonomous robot, and Fig. 3 a flowchart relating to the proposed method with steps S1 to S4.

[0028] The Fig. Figure 1 shows a schematic representation of the system 1 proposed here, with an example of an autonomous vehicle 2 and a possible movement path 3 additionally indicated. The autonomous vehicle 2 is generally freely movable within the area (the work environment). However, the autonomous vehicle 2 predominantly operates along predetermined paths. The autonomous vehicle has a radio modem 6.

[0029] Fig. Figure 2 shows a schematic representation of a journey of an autonomous vehicle 2. The vehicle 2 travels from waypoint a via waypoint b to waypoint c. In this area, there are three separate radio signal access points 4 that support a specific area ([1], [2], [3]). At waypoint b, all Wi-Fi areas overlap. The route planning algorithm of the fleet management system knows the Wi-Fi areas and the route that the autonomous vehicle 2 will take and adds the information to the waypoint that the autonomous vehicle 2 should switch from its current Wi-Fi [3] to the next Wi-Fi [2].

[0030] Scanning the Wi-Fi infrastructure can be performed once, temporarily, or continuously (continuously) while the autonomous vehicle 2 (and the vehicle itself) is driving to update the Wi-Fi information. If new obstacles, such as machinery, are placed in the facility or work area and / or walls are built or removed, this will affect the range of the Wi-Fi access points.

[0031] The proposed solution makes it possible to detect even temporary and / or sudden changes in the radio signal access points 4 that are reachable or available in a certain area with suitable quality and to adapt the changes in the radio signal access points 4 accordingly in a timely manner, if necessary immediately.

[0032] Analysis of Wi-Fi data can be performed to obtain information about when an update should be performed on a specific Wi-Fi zone.

[0033] The data can be used to check whether a route that vehicle 2 is supposed to take has a blind spot in terms of Wi-Fi strength. Additional waypoints must be released so that the vehicle can drive through this area without exchanging information with the fleet management system. The data can also be used to provide information about where another wireless signal access point 4 should be installed.

[0034] The Fig. Figure 3 shows a flow chart of the method proposed here, comprising steps S1 to S4. Here, S1: Detection of a local distribution of a radio signal strength and / or of a coverage area of ​​a respective radio signal access point 4 by an autonomous vehicle 2, S2: Transmission of the recorded data from the autonomous vehicle 2 to a networked computer 5, S3: Analysis of the acquired data by the computer 5 and / or creation of a zone map by the computer 5 for the radio signal access points 4 in the working environment, and S4: Provision of the analyzed data and / or the zone map for route planning of autonomous vehicles 2 in the working environment.

[0035] Using information about the Wi-Fi infrastructure from the Wi-Fi server (recorded during operation) together with the route planning algorithm improves switching to the correct access point. It also prevents switching to the wrong access point and / or excessively long journeys with weak Wi-Fi or WLAN strength. This improves traffic conditions within the facility because the robot doesn't have to stop due to weak Wi-Fi strength, and the monitoring system (fleet management system) doesn't receive delayed information about the robot's status (e.g., position). List of reference symbols 1 system 2 Autonomous vehicle 3 Movement path 4 Radio signal access point 5 (networked) computers 6 wireless modems

Claims

[1] System (1), comprising at least - an autonomous vehicle (2) with a radio modem (6), - a radio network with several radio signal access points (4) in the working environment of the autonomous vehicle (2), wherein the system (1) is configured to detect a local distribution of a radio signal strength and / or a coverage area of ​​a respective radio signal access point (4) with the autonomous vehicle (2) and to send the detected data from the autonomous vehicle (2) to a networked computer (5), wherein the acquired data is analyzed by the computer (5) and / or mapped in the form of a zone map for the radio signal access points (4) in the working environment, wherein the system (1) is further configured to provide the analyzed data and / or the zone map for route planning of autonomous vehicles (2) in the working environment. [2] System (1) according to claim 1, wherein the analyzed data and / or the zone map comprises location areas in the working environment at which the autonomous vehicle (2) is to change from a first radio signal access point (4) to a second, adjacent radio signal access point (4). [3] System (1) according to claim 1 or 2, wherein the computer comprises a server. [4] System (1) according to one of the preceding claims, wherein the computer (5) is wirelessly connected to the autonomous vehicle (2). [5] System (1) according to one of the preceding claims, wherein the radio network is a WLAN network and / or a ZigBee network and / or a Z-Wave network. [6] Method for controlling the changes between radio signal access points (4) in a radio network with a plurality of radio signal access points (4) in a working environment for autonomous vehicles (2), comprising at least the following steps: a. detection of a local distribution of a radio signal strength and / or of a coverage area of ​​a respective radio signal access point (4) by an autonomous vehicle (2), b. Transmission of the recorded data from the autonomous vehicle (2) to a networked computer (5), c. Analysis of the collected data by the computer (5) and / or creation of a zone map by the computer (5) for the radio signal access points (4) in the working environment, d. Providing the analyzed data and / or the zone map for route planning of autonomous vehicles (2) in the working environment. [7] Method according to claim 6, further comprising determining location areas in the working environment on the basis of the analyzed data and / or the zone maps at which the autonomous vehicle (2) is to change from a first radio signal access point (4) to a second, adjacent radio signal access point (4).

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