Mobile device, communication control method for mobile device, and program

Abstract

To allow a communication function of a robot to have redundancy with a simple configuration.SOLUTION: A robot 20 as a mobile body device capable of autonomous movement has a communication function with a first network 40A and a second network 40B, which are wireless communication networks, and is constantly linked to each of the first network 40A and the second network 40B. The first network 40A among them is preferentially selected and used for wireless communication of the robot 20.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a mobile device, a communication control method for a mobile device, and a program.

Background Art

[0002] Autonomous robots as mobile devices have come to be used for various purposes such as patrol monitoring and cleaning inside buildings. Usually, an autonomous robot has a wireless communication function, and transmits information such as its own position and operating state to a management device for managing each autonomous robot through a telecommunications line such as a mobile communication network, and also receives various commands from the management device. For example, Patent Document 1 describes a monitoring system including a mobile robot that can operate autonomously and a monitoring device. The mobile robot is provided with a second communication unit and is configured to be connectable to a telecommunications line by a wireless communication function using, for example, a telephone line or a wireless LAN. The mobile robot and the monitoring device are configured to be able to communicate via a telecommunications line.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to Patent Document 1, when a communication failure occurs in the telecommunications line, communication between the mobile robot and the monitoring device becomes impossible, and there is a problem that information cannot be exchanged between the mobile robot and the monitoring device. To address this problem, it is conceivable to make the communication line redundant, but there are problems to be solved such as the cost of multiplexing the communication line and the need to minimize the downtime when switching the communication line due to a failure.

[0005] One object of the present invention is to provide a mobile device, a communication control method for a mobile device, and a program that can give redundancy to the communication function of the mobile device with a simple configuration. **Means for Solving the Problems**

[0006] One aspect of the present invention is a mobile device capable of autonomous movement, comprising a processing unit that provides a communication function with at least two different wireless communication networks, the processing unit being constantly linked to each of the at least two different wireless communication networks, and configured such that a predetermined one of the wireless communication networks is preferentially selected for use in the wireless communication of the mobile device. **Advantages of the Invention**

[0007] According to the present invention, redundancy can be provided to the communication function of a mobile device with a simple configuration. **Brief Description of the Drawings**

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0009] Hereinafter, the present invention will be described with reference to the accompanying drawings in accordance with its embodiments. [System Configuration] FIG. 1 shows a system configuration diagram illustrating the system configuration of a robot system 1, which is a mobile body device system according to an embodiment of the present invention. As shown in FIG. 1, the robot system 1 includes a management device 10, a robot 20, and a charging device 30.

[0010] The management device 10 and the robot 20 are communicably connected to each other via a network 40. The network 40 is composed of, for example, a wireless communication line such as a mobile body communication network, a local area network (LAN), or a wide area network (WAN). The charging device 30 does not have an intercommunication function with other devices through the network 40, but has a function of broadcasting in one direction toward the robot 20. In the present embodiment, the network 40 includes at least two different types of wireless communication networks. Different types of wireless communication networks are, for example, wireless communication networks respectively operated by at least two different carriers.

[0011] The management device 10 is a device for managing the operating state of the robot system 1, and has functions such as collecting information on the operating state from the robot 20 and the charging device 30, managing the collected information, and outputting it to the outside as necessary. The management device 10 is typically realized by an electronic device such as a server device or a personal computer.

[0012] The robot 20 is a mobile device capable of autonomous movement with a motor driven by a battery as a power source. For example, it is suitably used for patrol operations within facilities such as office buildings, but is not limited to this, and can be widely applied to operations such as cleaning, guiding, and facility inspection. The robot 20 has a function of setting a path while measuring the surrounding environment in real time by a precise distance measurement system using laser light generally called LiDAR (Light Detection And Ranging). When the battery of the robot 20 needs to be charged, the robot 20 approaches a pre-specified charging device 30 and is configured to be mechanically and electrically connected to the charging device 30 to charge the battery.

[0013] The charging device 30 is a device equipped with a charger for charging the battery of the robot 20. Except for being connected to an appropriate power source such as commercial AC100V, it has a simple stand-alone configuration. When the charging device 30 is in an operating state connected to a power source, it constantly broadcasts charging device information including information about its own operating state to the surrounding area, but does not have a function of receiving external operation inputs. The robot system 1 is provided with a necessary number of charging devices 30 according to the number of robots 20 to be arranged, the size of their operating areas, etc.

[0014] [Configuration of Robot 20] Next, the configuration of the robot 20 will be described. FIG. 2 is a block diagram illustrating the configuration of the hardware and functional blocks of the robot 20 in an embodiment of the present invention. As shown in FIG. 2, the robot 20 is an information processing device having a function of setting a path based on recognition of the surrounding environment by sensors and autonomously moving, and a communication function. Specifically, the robot 20 includes a processor 21, a memory 22, an auxiliary storage unit 23, a network communication unit 24A, a charging device communication unit 24B, a data IO unit 25, an input / output unit 26, a drive unit 27, a LiDAR device 28, and a battery 29. Note that the robot 20 does not necessarily have to be configured from the functional blocks illustrated in FIG. 2, and may be realized by other configurations that provide equivalent functions.

[0015] The processor 21 is configured using arithmetic devices such as a CPU and a GPU, reads various programs and data from the memory 22 and the auxiliary storage unit 23 described later, and is an arithmetic device that executes data processing for realizing the functions of the robot 20.

[0016] The memory 22 is a storage area for various programs and various data for causing the hardware group to function as the robot 20, and can be configured by storage devices such as a ROM, a RAM, and a flash memory. In the present embodiment, programs of a management control unit 221, a drive control unit 222, and a communication control unit 223 are stored in the memory 22. The functions of each program will be described later.

[0017] The auxiliary storage unit 23 is a storage device that provides a storage area for storing data and the like used by each program stored in the memory 22, and is configured by, for example, a semiconductor drive (SSD), a hard disk drive (HDD), or the like. In the present embodiment, charging device information 231, robot information 232, and map information 233 are stored in the auxiliary storage unit 23.

[0018] The network communication unit 24A provides a two-way communication function with the management device 10 through the network 40, and is composed of hardware such as a mobile communication module and a network interface card (NIC), for example. The charging device communication unit 24B provides a reception function for one-way communication broadcast from the charging device 30, and is composed of hardware such as a wireless communication module compliant with the IEEE 802.15.4 standard, for example. The network communication unit 24A is provided with a communication management unit 243 for managing the communication functions of the first communication module 241 and the second communication module 242. The communication management unit 243 includes driver software for operating the first communication module 241 and the second communication module 242, and software that provides a teaming function that enables the first communication module 241 and the second communication module 242 to be integrated and operated as one virtual NIC.

[0019] Fig. 4 shows a configuration example of the network communication unit 24A in this embodiment. As described above, the network communication unit 24A is provided with the first communication module 241 and the second communication module 242, which are two independent sets of physical NICs. In this embodiment, the first network 40A and the second network 40B are used as the network 40 that communicably connects the robot 20 and the management device 10. The first network 40A is operated by carrier A, and the second network 40B is operated by carrier B, which is different from carrier A. A first SIM (Subscriber Identity Module) card for managing the subscriber information of carrier A is connected to the first communication module 241. Also, a second SIM card for managing the subscriber information of carrier B is connected to the second communication module 242. The first communication module 241 can be connected to the base station of carrier A in the first network 40A via the first antenna AN1. The second communication module 242 can be connected to the base station of carrier B in the second network 40B via the second antenna AN2. The communication management unit 243 has the functions of the drivers of the first communication module 241 and the second communication module 242, and is software that provides a teaming function for integrating the first communication module 241 and the second communication module 242 to operate as one virtual NIC. The communication management unit 243 of the present embodiment provides a teaming function in the active-backup mode. The first communication module 241 connected to the first network 40A is the active system, and the second communication module 242 connected to the second network 40B is the backup system. Normally, the communication between the robot 20 and the management device 10 is executed by the first communication module 241 that can be connected to the first network 40A operated by carrier A. Which network is set as the active system may be determined according to the system policy. In the present embodiment, carrier A with a lower communication cost than carrier B is set as the active system from an economic perspective. Thereby, except when a failure or a deterioration of communication conditions occurs in the first network 40A or a failure occurs in the first communication module 241, the communication is performed using the first communication module 241 and the first network 40A that are the active systems.

[0020] The data I / O unit 25 provides a data input / output function between the processor 21 and the network communication unit 24A, the charging device communication unit 24B, and the input / output unit 26, and includes various interface circuits.

[0021] The input / output unit 26 is composed of various input devices such as a keyboard, a touch panel, and a microphone that enable data input from the outside to the robot 20, and output devices such as a monitor display and a speaker for outputting output display data, output voice data, etc. generated by the processor 21.

[0022] The drive unit 27 includes a power source such as a motor for enabling the robot 20 to move, and hardware such as a speed reduction and transmission mechanism.

[0023] The LiDAR device 28 is a ranging device using laser light and has a function of measuring the distance to an object around the robot 20. The obtained measurement data is passed to a program executed by the processor 21 and is used for map creation around the robot 20, path setting of the robot 20 based on the map, and movement control. Note that other ranging devices such as a millimeter-wave radar can also be used for the ranging function.

[0024] The battery 29 has a function of supplying power to a drive unit 27 including a motor and the like and a control system of the robot 20 such as the processor 21, and is composed of a rechargeable secondary battery in an appropriate form.

[0025] The management control unit 221, the drive control unit 222, and the communication control unit 223, which are programs stored in the memory 22, will be described.

[0026] The management control unit 221 has a function of controlling the overall operation of the robot 20 based on information regarding the operating state of the robot 20 and information regarding the operating state of the charging device received from the charging device 30. The functions of the management control unit 221 include map creation based on the ranging data of the LiDAR device 28, collection of information regarding the surrounding environment by various sensors, path control of the robot 20 based on the collected data, control of a series of operations for charging the robot 20 based on information regarding the charge state of the battery 29, and the like. Note that the management control unit 221 can be configured as a combination of program modules that execute these individual controls.

[0027] The drive control unit 222 executes drive control of the motor constituting the drive unit 27 and the like in order to execute movement control of the robot 20 under the control of the management control unit 221.

[0028] The communication control unit 223 has a function of controlling data communication between the processor 21 and the network communication unit 24A, the charging device communication unit 24B, and the like.

[0029] The program stored in the memory 22 executes data processing for realizing the assigned functions by using the charging device information 231, the robot information 232, and the map information 233 stored in the auxiliary storage unit 23. Here, the charging device information 231 is information indicating the operating state of the charging device 30 collected in the charging device 30, and is sent to the robot 20 by one-way communication broadcast from each charging device 30. The charging device information 231 of each charging device 30 is sent from each robot 20 to the management device 10 and is managed in the management device 10. In the present embodiment, the charging device information 231 includes the charging device ID which is the unique identification information of each charging device 30, the manufacturing number unique to each charging device 30, the charger on / off information indicating the state of the charger, the error information which is information regarding the error occurring in the charging device 30, the temperature information indicating the temperature at a predetermined measurement location in the charging device 30, the plug voltage indicating the charging plug terminal voltage of the robot 20 connected to the charging device 30, the charger on / off count indicating the total on / off count of the charger, and each item of the error history indicating the history of errors that have occurred in the charging device 30 in the past. Note that the items included in the charging device information 231 are not limited to this example and can be changed as appropriate.

[0030] The robot information 232 is information regarding the operating state of the robot 20 collected by the management control unit 221 in each robot 20. The robot information 232 collected in each robot 20 is sent to the management device 10 and is used for the management of the robot 20 in the management device 10. The robot information 232 of the present embodiment includes each item of the robot ID which is the unique identification information of each robot 20, the position information which is information indicating the location of each robot 20, the speed information which is information indicating the moving speed of each robot 20, the battery voltage indicating the terminal voltage of the battery 29 mounted on each robot 20, and the error information which is information regarding the error occurring in each robot 20. Note that the items included in the robot information 232 are not limited to this example and can be changed as appropriate.

[0031] The map information 233 numerically represents the environment of the operating area of the robot 20 to enable autonomous movement of the robot 20, and is expressed as a set of coordinates of feature points representing the paths along which the robot 20 can move. The X coordinate, Y coordinate of the feature points, and information related to the feature points are recorded in combination. The feature points also include the coordinates of the installation position of the charging device 30, and the charging device ID of the corresponding charging device 30 is described. When charging is required, each robot 20 can be controlled to determine the nearest charging device 30 from its own position and the position of the charging device 30 recorded in the map information 233 and move to that charging device 30. Note that the items included in the map information 233 are not limited to this example and can be changed as appropriate.

[0032] [Configuration of the management device 10] Next, the configuration of the management device 10 will be described. FIG. 3 is a block diagram illustrating the hardware and functional block configuration of the management device 10 in an embodiment of the present invention. As shown in FIG. 3, the management device 10 is an information processing device having a function of collecting and recording information regarding the operating states of each robot 20 and the charging device 30 transmitted from each robot 20 and managing the robot system 1 based on this information. Specifically, the management device 10 includes a processor 11, a memory 12, an auxiliary storage unit 13, a communication unit 14, a data I / O unit 15, and an input / output unit 16.

[0033] The processor 11 is configured using an arithmetic device such as a CPU, and is an arithmetic device that reads various programs and data from the memory 12 and the auxiliary storage unit 13 described later and executes data processing for realizing the functions of the management device 10.

[0034] The memory 12 is a storage area for various programs and various data for causing the hardware group to function as the management device 10, and can be configured by storage devices such as ROM, RAM, and flash memory. In the present embodiment, programs of a management control unit 121 for controlling the overall operation of the management device 10 and a communication control unit 122 for controlling communication with each robot 20 are stored in the memory 12.

[0035] The auxiliary storage unit 13 is a storage device that provides a storage area for storing data and the like used by each program stored in the memory 12, and is constituted by, for example, a solid state drive (SSD), a hard disk drive (HDD), or the like. In the present embodiment, the charging device information 131, the robot information 132, and the map information 133 are stored in the auxiliary storage unit 13. The charging device information 131, the robot information 132, and the map information 133 are the same as the charging device information 231, the robot information 232, and the map information 233 stored in the auxiliary storage unit 23 of the robot 20.

[0036] The communication unit 14 provides a communication function with each robot 20 through the network 40, and is constituted by hardware such as, for example, a mobile communication module and a network interface card (NIC).

[0037] The data I / O unit 15 provides a data input / output function between the processor 11 and the communication unit 14 and the input / output unit 16, and includes various interface circuits.

[0038] The input / output unit 16 is composed of various input devices such as a keyboard, a touch panel, and a microphone that enable data input from the outside to the management device 10, and output devices such as a monitor display and a speaker for outputting output display data, output voice data, etc. generated by the processor 11.

[0039] [Communication Control of Robot 20] Next, the communication control executed in the robot 20 of the robot system 1 having the configuration described above will be described. FIG. 5 illustrates, in a flowchart, the flow of communication control processing executed by the communication management unit 243 in the network communication unit 24A of the robot 20. The control flow in FIG. 5 starts when the robot 20 is activated and enters the operating state, and is continuously executed during the operation of the robot 20 thereafter.

[0040] In step S501, the communication management unit 243 of the robot 20 executes a teaming process that integrates the first communication module 241 and the second communication module 242 to function as one virtual NIC. The teaming mode is the active-backup mode. In step S502, the first communication module 241 that can be connected to the first network 40A with relatively low communication costs is preferentially selected as the active system. The second communication module 242 is set as the backup system. Both the first communication module 241 and the second communication module 242 always establish links with the first network 40A and the second network 40B respectively, and normal communication is executed through the first network 40A.

[0041] In step S503, the communication management unit 243 acquires the response times of the first communication module 241 and the second communication module 242 for communication with the first network 40A and the second network 40B respectively. Specifically, the communication management unit 243 uses the ping command to check the response times in the communication between the first communication module 241 and the second communication module 242 and the management device 10 executed via the first network 40A and the second network 40B respectively.

[0042] In step S504, the communication management unit 243 determines which network, the first network 40A or the second network 40B, has a shorter response time. If it is determined that the response time of the second network 40B operated by carrier B is shorter (step S504 is YES), the communication management unit 243 proceeds to step S505. If it is determined that the response time of the first network 40A operated by carrier A is shorter or there is no difference in the response times (step S504 is NO), the communication management unit 243 returns to step S503. In this case, the first communication module 241 continues to be used for communication.

[0043] In step S505, the communication management unit 243 determines whether the communication standard applied to the second network 40B (e.g., 2G, 3G, LTE, 5G, etc.) is equivalent to or faster than the communication standard applied to the first network 40A. If it is determined that the communication standard applied to the second network 40B is equivalent to or faster than the communication standard applied to the first network 40A (step S505 is YES), the communication management unit 243 proceeds to step S506. If it is determined that the communication standard applied to the second network 40B is slower than the communication standard applied to the first network 40A (step S505 is NO), the communication management unit 243 returns to step S503. In this case, the first communication module 241 continues to be used for communication.

[0044] In step S506, the communication management unit 243 determines whether the signal strength of the second network 40B is equal to or greater than a predetermined value. If it is determined that the signal strength of the second network 40B is equal to or greater than the predetermined value (step S506 is YES), the communication management unit 243 proceeds to step S507. If it is determined that the signal strength of the second network 40B is not equal to or greater than the predetermined value (step S506 is NO), the communication management unit 243 returns to step S503. In this case, the first communication module 241 continues to be used for communication.

[0045] In step S507, the communication management unit 243 selects the second communication module 242, which is a backup system, and switches the communication to the second network 40B. This is because it is determined that the response time of communication using the second network 40B is shorter, the communication standard is equivalent to or faster, and the signal strength of the second network 40B is equal to or greater than the predetermined value, which meets the predetermined conditions for communication system switching. That is, the communication management unit 243 has selected to continue communication using the second network 40B, which has a faster response and a more stable signal strength than the first network 40A.

[0046] After that, the communication management unit 243 continues to monitor the communication states of the first network 40A and the second network 40B, and if a predetermined condition is satisfied, performs a process of returning to communication using the first communication module 241 which is the active system.

[0047] That is, in step S508, the communication management unit 243 acquires the response times of communication between the first communication module 241 and the second communication module 242 and the first network 40A and the second network 40B respectively.

[0048] In step S509, the communication management unit 243 determines which of the first network 40A and the second network 40B has a shorter response time. If it is determined that the response time of the first network 40A operated by carrier A is shorter (step S509 is YES), the communication management unit 243 proceeds to step S510. If it is determined that the response time of the second network 40B operated by carrier B is shorter or there is no difference in the response times (step S509 is NO), the communication management unit 243 returns to step S508. In this case, the second communication module 242 continues to be used for communication.

[0049] In step S510, the communication management unit 243 determines whether the communication standard applied to the first network 40A is the same as or faster than the communication standard applied to the second network 40B. If it is determined that the communication standard applied to the first network 40A is the same as or faster than the communication standard applied to the second network 40B (step S510 is YES), the communication management unit 243 proceeds to step S511. If it is determined that the communication standard applied to the first network 40A is slower than the communication standard applied to the second network 40B (step S510 is NO), the communication management unit 243 returns to step S508. In this case, the second communication module 242 continues to be used for communication.

[0050] In step S511, the communication management unit 243 determines whether the signal strength of the first network 40A is equal to or greater than a predetermined value. If it is determined that the signal strength of the first network 40A is equal to or greater than the predetermined value (step S511 is YES), the communication management unit 243 proceeds to step S502 and executes a process of returning to a configuration in which the communication of the robot 20 is performed using the first network 40A by the first communication module 241. If it is determined that the signal strength of the first network 40A is not equal to or greater than the predetermined value (step S511 is NO), the communication management unit 243 returns to step S508. In this case, the second communication module 242 continues to be used for communication.

[0051] According to the above communication control process, the communication function of the robot can be made redundant with a simple configuration.

[0052] The processing unit may compare the communication state of the predetermined wireless communication network with the communication states of the other wireless communication networks, and select one of the other wireless communication networks for which the predetermined condition is satisfied to continue providing the communication function when the predetermined condition is satisfied. In this way, it is possible to compare conditions such as communication speed and signal strength and switch the communication to a network with better conditions.

[0053] After switching the communication from the predetermined wireless communication network to the other wireless communication network, the processing unit may compare the communication state of the predetermined wireless communication network with the communication states of the other wireless communication networks, and select the predetermined wireless communication network to continue providing the communication function when the predetermined condition is satisfied for the predetermined wireless communication network. In this way, when the communication state of the network that was initially preferentially selected becomes dominant, the communication function can be returned to the initial network so that the advantages (such as communication cost) of the initial network can be enjoyed as much as possible.

[0054] When communication switching between the wireless communication networks is performed, the processing unit may suppress execution of the next wireless communication network switching process for a predetermined time. By doing so, it is possible to prevent frequent communication switching between wireless communication networks.

[0055] The predetermined wireless communication network may be the one with the lowest communication cost among the at least two types of wireless communication networks. By doing so, the wireless communication network with the lowest communication cost will be preferentially selected, and it will be possible to operate the robot system economically.

[0056] The predetermined conditions can include that the communication speed is relatively fast and the signal strength of the communication is equal to or greater than a predetermined value. By doing so, the communication of the robot can be performed under a faster and more stable communication state.

[0057] The above-described series of processes can be executed by hardware or by software. In other words, the functional configurations in FIGS. 2 to 4 are merely examples and are not particularly limited. That is, it is sufficient that the management device 10 and the robot 20 are provided with functions capable of executing the above-described series of processes as a whole, and the specific functional blocks used to realize this function are not particularly limited to the examples in FIGS. 2 to 4. Also, one functional block may be configured by hardware alone, by software alone, or by a combination thereof. The functional configuration in the present embodiment is realized by a processor that executes arithmetic processing, and the processors that can be used in the present embodiment include those configured by various processing devices such as a single processor, a multi-processor, and a multi-core processor, as well as those in which these various processing devices are combined with a processing circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

[0058] When a series of processes are to be executed by software, the programs that make up the software are installed on a computer or the like from a network or a recording medium. The computer may be a computer incorporated in dedicated hardware. Also, the computer may be a computer capable of executing various functions by installing various programs, for example, a general-purpose personal computer.

[0059] A recording medium containing such a program is not only composed of a removable medium such as a USB memory distributed separately from the device body to provide the program to the user, but also composed of a recording medium or the like provided to the user in a state pre-installed in the device body. The removable medium is composed of, for example, a magnetic disk (including a floppy disk), an optical disk, or a magneto-optical disk. The optical disk is composed of, for example, a CD-ROM (Compact Disk-Read Only Memory), a DVD (Digital Versatile Disk), a Blu-ray (registered trademark) Disc (Blu-ray disk), etc. The magneto-optical disk is composed of an MD (Mini-Disk), etc. Also, the recording medium provided to the user in a state pre-installed in the device body is composed of, for example, a ROM in which a program is recorded, a hard disk, etc.

[0060] Note that in this specification, the step of describing a program recorded on a recording medium includes not only processes that are performed in chronological order according to that order, but also processes that are executed in parallel or individually even if they are not necessarily processed in chronological order.

[0061] As described above, some embodiments of the present invention have been explained. However, these embodiments are merely examples and do not limit the technical scope of the present invention. The present invention can take various other embodiments, and it is also possible to combine each configuration of the above embodiments and modifications. Furthermore, various changes such as omission and substitution can be made without departing from the gist of the present invention. These embodiments and their modifications are included in the scope and gist of the invention described in this specification and the like, and are also included in the invention described in the claims and the equivalent scope thereof.

Explanation of Signs

[0062] 1 Robot system 10 Management device 11, 21 Processor 12, 22 Memory 20 Robot 24A Network communication unit 24B Charging device communication unit 30 Charging device 40 Network 223 Communication control unit 241 First communication module 242 Second communication module 243 Communication management unit

Claims

1. A mobile device capable of autonomous movement, comprising a processing unit that provides communication functions with at least two different wireless communication networks, wherein the processing unit always forms a link with each of the at least two different wireless communication networks, and a predetermined one of the wireless communication networks with the lowest communication cost is preferentially selected for the wireless communication of the mobile device, and the processing unit selects another wireless communication network for which the predetermined condition is satisfied and continues to provide the communication function when the predetermined condition is satisfied, wherein the predetermined condition includes that the other wireless communication network has a higher communication speed, the communication standard of the other wireless communication network is equal to or higher than that of the predetermined wireless communication network, and the signal strength of the other wireless communication network is equal to or higher than a predetermined value. Mobile device.

2. The mobile device according to claim 1, wherein after the processing unit switches communication from the predetermined wireless communication network to the other wireless communication network, when the predetermined condition is satisfied for the predetermined wireless communication network, the predetermined wireless communication network is selected and the provision of the communication function is continued.

3. The mobile device according to claim 1 or 2, wherein when communication switching between the wireless communication networks is performed, the processing unit suppresses the execution of the next wireless communication network switching process for a predetermined time.

4. A communication control method for a mobile device capable of autonomous movement, wherein the mobile device comprises a processing unit that provides communication functions with at least two different wireless communication networks, the processing unit always forms a link with each of the at least two different wireless communication networks, and a predetermined one of the wireless communication networks with the lowest communication cost is preferentially selected for the wireless communication of the mobile device, and the processing unit selects another wireless communication network for which the predetermined condition is satisfied and continues to provide the communication function when the predetermined condition is satisfied. The communication control method of the mobile device includes the following predetermined conditions: the other wireless communication network has a higher communication speed, the communication standard of the other wireless communication network is equivalent to or higher than that of the predetermined wireless communication network, and the signal strength of the other wireless communication network is equal to or higher than a predetermined value.

5. In a processing unit provided in a mobile device capable of autonomous movement, which provides communication functions with at least two different wireless communication networks, always establish a link with each of the at least two different wireless communication networks, and preferentially select a predetermined wireless communication network that has the lowest communication cost among them to provide wireless communication for the mobile device. When a predetermined condition is satisfied, select the other wireless communication network for which the predetermined condition is satisfied and continue to provide the communication function. The predetermined conditions include that the other wireless communication network has a higher communication speed, the communication standard of the other wireless communication network is equivalent to or higher than that of the predetermined wireless communication network, and the signal strength of the other wireless communication network is equal to or higher than a predetermined value. Program

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