Mobile communication devices and wireless communication systems

Abstract

The present invention provides a mobile communication device and a wireless communication system that can reduce the power consumption of a mobile communication device while reducing the load on the communication processing equipment of a fixed communication device during wireless communication on a manufacturing line between a mobile communication device and a fixed communication device. [Solution] The mobile communication device 50 includes an illuminance detection unit 65, a determination unit 67, and a switching unit 69. The determination unit 67 compares the illuminance detected by the illuminance detection unit 65 with a threshold TH to determine whether the mobile communication device 50 has entered the external area RG2 from a specific area RG1 where wireless communication with the fixed communication device 80 is possible. If the determination unit 67 determines that the mobile communication device 50 has entered the external area RG2, the switching unit 69 switches the operating mode of the mobile communication device 50 from normal mode to low power consumption mode.

Description

Technical Field

[0001] The present invention relates to a mobile communication device and a wireless communication system.

Background Art

[0002] Conventionally, in a manufacturing factory, a system for performing wireless communication between a mobile communication device that moves along a conveyance path of a manufacturing line together with a manufacturing target and a fixed communication device provided outside the manufacturing line is known. In this system, when the mobile communication device enters a specific area where wireless communication with the fixed communication device is possible, it transmits information on the manufacturing target to the fixed communication device.

[0003] The system disclosed in Patent Document 1 includes a detector that detects that the mobile communication device has entered a specific area where wireless communication with the fixed communication device is possible.

[0004] When the detector detects that the mobile communication device has entered the specific area, it uses a command means to instruct the fixed communication device to start wireless communication with the mobile communication device. When instructed to start wireless communication, the fixed communication device transmits a transmission request signal to the mobile communication device to acquire information on the manufacturing target from the mobile communication device.

[0005] Thereby, since the fixed communication device does not need to transmit the transmission request signal periodically, the load on the communication process can be reduced.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the system disclosed in Patent Document 1, the mobile communication device is always in a state where it can receive transmission request signals from the fixed communication device. Therefore, even outside of the specific area where wireless communication with the fixed communication device is possible, the mobile communication device maintains a state where it can receive transmission request signals from the fixed communication device, resulting in unnecessary power consumption.

[0008] Therefore, further improvements were desired in order to reduce the load on fixed communication devices for communication processing while suppressing power consumption of mobile communication devices.

[0009] This invention has been made in view of the problems of the prior art. The object of this invention is to provide a mobile communication device and a wireless communication system that can reduce the load on the communication processing device while suppressing the power consumption of the mobile communication device in wireless communication on a manufacturing line between a mobile communication device and a fixed communication device. [Means for solving the problem]

[0010] A mobile communication device according to an aspect of the present invention is mounted on a work board that moves along a transport path of a manufacturing line and comprises a storage unit, an illuminance detection unit, a determination unit, a switching unit, a first transmission unit, a reception unit, an acquisition unit, and a second transmission unit. The storage unit stores a threshold value that distinguishes between the illuminance of a specific area that can be wirelessly communicated with a fixed communication device provided outside the manufacturing line and the illuminance of an external area other than the specific area. The illuminance detection unit periodically detects the illuminance on the work board. The determination unit compares the illuminance detected by the illuminance detection unit with the threshold value to determine whether the mobile communication device has entered the specific area from the external area, and whether it has entered the external area from the specific area. If the determination unit determines that the mobile communication device has entered the specific area, the switching unit switches the operating mode of the mobile communication device from a low power consumption mode to a normal mode. When the operating mode switches to the normal mode, the first transmitting unit transmits a first notification signal to the fixed communication device to notify the transition to the normal mode. The receiving unit receives a transmission request signal from the fixed communication device in response to the transmission of the first notification signal. The acquisition unit acquires information about the object to be manufactured placed on the work board in response to the receipt of the transmission request signal. The second transmitting unit transmits the information about the object to be manufactured acquired by the acquisition unit to the fixed communication device. The mobile communication device can wirelessly communicate with the fixed communication device within a predetermined range from the boundary between the specific area and the external area, located downstream in the direction of movement of the work board in the external area. When the determination unit determines that the mobile communication device has entered the external area, the first transmitting unit transmits a second notification signal to the fixed communication device to notify the transition to the low power consumption mode. When the first transmitting unit transmits the second notification signal, the switching unit switches the operating mode of the mobile communication device from the normal mode to the low power consumption mode. In the low power consumption mode, the operation of the first transmitting unit, the second transmitting unit, the receiving unit, and the acquisition unit is stopped.

[0011] A wireless communication system according to a second aspect of the present invention comprises a plurality of mobile communication devices attached to a work board that moves along a transport path of a manufacturing line, and a fixed communication device provided outside the manufacturing line. In a specific area where wireless communication is possible with the fixed communication device, inspection work is performed on a manufacturing object placed on the work board. The plurality of mobile communication devices acquire inspection results for a plurality of parts of the manufacturing object. Each mobile communication device comprises a storage unit, an illuminance detection unit, a determination unit, a switching unit, a first transmission unit, a first reception unit, an acquisition unit, and a second transmission unit. The storage unit stores a threshold value that distinguishes the illuminance of the specific area from the illuminance of an external area other than the specific area. The illuminance detection unit periodically detects the illuminance on the work board. The determination unit compares the illuminance detected by the illuminance detection unit with the threshold value to determine whether the mobile communication device has entered the specific area from the external area, and whether it has entered the external area from the specific area. The switching unit switches the operating mode of the mobile communication device from low-power mode to normal mode when the determination unit determines that the mobile communication device has entered the specific area. When the operating mode switches to normal mode, the first transmitting unit transmits a first notification signal to the fixed communication device to notify the transition to normal mode. The first receiving unit receives a transmission request signal from the fixed communication device in response to the transmission of the first notification signal. The acquisition unit acquires the inspection result of the corresponding part among the plurality of parts of the manufactured object in response to the receipt of the transmission request signal. The second transmitting unit transmits the inspection result acquired by the acquisition unit to the fixed communication device. The fixed communication device comprises a second receiving unit, a third transmitting unit, a third receiving unit, and a fourth transmitting unit. The second receiving unit receives the first notification signal from each mobile communication device. When the second receiving unit receives the first notification signal from all of the plurality of mobile communication devices, the third transmitting unit notifies the transmission request signal. The third receiving unit receives the inspection results from each of the plurality of mobile communication devices in response to the notification of the transmission request signal. The fourth transmitting unit transmits the received inspection results to the management device.Each mobile communication device can wirelessly communicate with the fixed communication device within a predetermined range from the boundary between the specific area and the external area, located downstream in the direction of movement of the work plate within the external area. When the determination unit determines that the mobile communication device has entered the external area, the first transmission unit transmits a second notification signal to the fixed communication device to notify it of the transition to the low power consumption mode. When the first transmission unit transmits the second notification signal, the switching unit switches the operating mode of the mobile communication device from the normal mode to the low power consumption mode. In the low power consumption mode, the operation of the first transmission unit, the second transmission unit, the first reception unit, and the acquisition unit is stopped. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a mobile communication device and a wireless communication system that can reduce the load on the fixed communication device's communication processing while suppressing the power consumption of the mobile communication device in wireless communication on a manufacturing line between a mobile communication device and a fixed communication device. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a schematic diagram of the overall configuration of a manufacturing system to which the wireless communication system according to this embodiment is applied. [Figure 2] Figure 2 is a magnified view of a portion of the manufacturing line, including the area where the inspection process shown in Figure 1 is performed. [Figure 3] Figure 3 is a schematic diagram of the various devices provided on the workbench according to this embodiment. [Figure 4] Figure 4 is a block diagram showing the various devices installed on the workbench according to this embodiment. [Figure 5] Figure 5 is a block diagram showing an example of the configuration of the inspection apparatus according to this embodiment. [Figure 6] Figure 6 is a block diagram showing an example of the functional configuration of a mobile communication device according to this embodiment. [Figure 7]FIG. 7 is a block diagram showing an example of the hardware configuration of the mobile communication device according to the present embodiment. [Figure 8] FIG. 8 is a circuit diagram showing an example of the detection circuit of the mobile communication device according to the present embodiment. [Figure 9] FIG. 9 is a diagram showing an example of the characteristics of the photoreceptor used in the detection circuit of the mobile communication device according to the present embodiment. [Figure 10] FIG. 10 is a diagram for explaining the setting of the threshold value used in the detection circuit of the mobile communication device according to the present embodiment. [Figure 11] FIG. 11 is a diagram for explaining an example of the identification information assigned to the inspection device according to the present embodiment. [Figure 12] FIG. 12 is a diagram for explaining an example of the inspection result of the manufacturing target according to the present embodiment. [Figure 13] FIG. 13 is a block diagram showing an example of the functional configuration of the fixed communication device according to the present embodiment. [Figure 14] FIG. 14 is a diagram for explaining an example of the configuration of the communication frame according to the present embodiment. [Figure 15] FIG. 15 is a diagram for explaining an example of the type of the communication frame according to the present embodiment. [Figure 16] FIG. 16 is a diagram for explaining an example of the communication sequence according to the present embodiment. [Figure 17A] FIG. 17A is a diagram showing an example of the operation flowchart of the mobile communication device according to the present embodiment. [Figure 17B] FIG. 17B is a diagram showing an example of the operation flowchart of the mobile communication device according to the present embodiment. [Figure 18] FIG. 18 is a diagram showing an example of the operation flowchart of the fixed communication device according to the present embodiment. [Figure 19] FIG. 19 is an overall schematic configuration diagram of the manufacturing system according to a modification of the present embodiment. [Figure 20] FIG. 20 is a diagram for explaining the setting of the illuminance in the manufacturing system according to a modification of the present embodiment. [Figure 21]Figure 21 is a circuit diagram showing an example of a detection circuit used in a manufacturing system according to a modified example of this embodiment. [Figure 22] Figure 22 shows an example of an operation flowchart of a mobile communication device in a manufacturing system according to a modified example of this embodiment. [Modes for carrying out the invention]

[0014] The mobile communication device and wireless communication system according to this embodiment will be described in detail below with reference to the drawings. Note that identical or similar reference numerals are used for identical functions and components, and their descriptions will be omitted as appropriate.

[0015] [Manufacturing system configuration] First, the configuration of the manufacturing system 1 to which the wireless communication system 5 according to this embodiment is applied will be described. Figure 1 is an overall schematic diagram of the manufacturing system 1. Figure 2 is a partial enlarged view of the manufacturing line including the area where the inspection process IP shown in Figure 1 is performed. Figure 3 is a schematic diagram of the various devices provided on the work surface 10. Figure 4 is a block diagram of the various devices provided on the work surface 10.

[0016] As shown in Figure 1, the manufacturing system 1 is installed in a manufacturing plant. In the manufacturing plant, multiple manufacturing operations are performed along the manufacturing line. The manufacturing line consists of multiple work boards 10 supported by a conveyor belt 3. Each work board 10 moves in one direction along the manufacturing line by the conveyor belt 3. With this configuration, when each work board 10 enters the area where a particular manufacturing operation is performed, the worker performs the manufacturing operation on that work board 10. The work boards 10 are also referred to as assembly jig boards.

[0017] In this embodiment, the manufacturing line is formed in a ring shape, and some of the multiple work boards 10 have a straight section arranged in a horizontal row at predetermined intervals. With this configuration, each work board 10 circulates around the manufacturing line.

[0018] In this embodiment, the manufacturing process involves attaching parts to the product to be manufactured (assembly process) and inspecting the attachment of the parts (inspection process). Therefore, each time the work plate 10 completes a circuit of the manufacturing line, a product with parts attached is repeatedly manufactured. For example, if the product to be manufactured is a wire harness, the parts attached to the product are fixing members such as clamps used to secure the wire harness to a vehicle. Note that the assembly process is not shown in Figure 1. The process of inspecting the attachment of the parts is also referred to as the inspection process of the product to be manufactured.

[0019] In this embodiment, five parts are attached to different parts of the manufactured object during the assembly process. However, the number of parts attached to the manufactured object is not limited to five; it may be four or fewer, or six or more.

[0020] As shown in Figures 3 and 4, a power supply 20, inspection devices 30a to 30e, and mobile communication devices 50a to 50e are provided on the work board 10. The power supply 20 generates electricity using a power generation element such as a solar cell and stores the generated electricity in an energy storage element such as a secondary battery or capacitor. The power supply 20 may also be composed of a primary battery such as a dry cell.

[0021] When the work plate 10 enters the area where the inspection process IP is performed (inspection process area), the inspection devices 30a to 30e each inspect the mounting status of five components attached to the workpiece. The inspection devices 30a to 30e are each connected to the mobile communication devices 50a to 50e via communication lines.

[0022] Hereafter, unless it is necessary to distinguish between inspection devices 30a to 30e, they will simply be referred to as "inspection device 30". Furthermore, the number of inspection devices 30 is not limited to five; it may be four or fewer, or six or more, depending on the number of parts to be attached to the manufactured object. Inspection devices 30 are also referred to as part receiving jigs. The communication lines are also referred to as part detection lines.

[0023] When the work board 10 enters the area where the inspection process IP is performed (inspection process area), the mobile communication devices 50a to 50e each acquire the inspection results of the manufactured object from the inspection devices 30a to 30e. The mobile communication devices 50a to 50e are located at different positions relative to each other in the direction of movement of the work board 10. The mobile communication devices 50a to 50e are electrically connected to the power supply 20 via the power line 11 and the ground line 13. With this configuration, power is supplied to the mobile communication devices 50a to 50e from the power supply 20.

[0024] Hereafter, unless it is necessary to distinguish between the mobile communication devices 50a to 50e, they will simply be referred to as "mobile communication device 50". Furthermore, the number of mobile communication devices 50 is not limited to five; it may be four or fewer, or six or more, depending on the number of components attached to the manufactured object.

[0025] A fixed communication device 80 and a management device 100 are provided outside the manufacturing line. The fixed communication device 80 can communicate wirelessly with the mobile communication device 50 in the area where the inspection process IP is performed (inspection process area). The fixed communication device 80 is connected to the management device 100 via a communication line. The management device 100 is also referred to as an inspection result collection device.

[0026] The fixed communication device 80 acquires manufacturing information of the manufactured object, including the inspection results, from the mobile communication device 50 that has entered the area where the inspection process IP is performed, and transmits the acquired manufacturing information to the management device 100. The management device 100 manages the manufacturing information for each manufactured object. The management device 100 displays the manufacturing information for each manufactured object on a monitor in response to instructions from the worker. Note that the inspection results and manufacturing information of the manufactured object are collectively referred to as the information of the manufactured object.

[0027] [Wireless communication system] Next, the configuration of the wireless communication system 5 will be described. The wireless communication system 5 consists of a plurality of mobile communication devices 50 (50a to 50e), a fixed communication device 80, and a management device 100 in the manufacturing system 1. As described above, the plurality of mobile communication devices 50 (50a to 50e) are provided on each work board 10 that moves along the transport path of the manufacturing line, while the fixed communication device 80 and the management device 100 are provided outside the manufacturing line.

[0028] When the mobile communication device 50 enters the area where the inspection process IP is performed, it starts wireless communication with the fixed communication device 80, and when it exits the area where the inspection process IP is performed, it terminates wireless communication with the fixed communication device 80.Hereafter, the area where the inspection process IP is performed and the other areas in the manufacturing line other than the area where the inspection process IP is performed will be referred to as the specific area RG1 and the external area RG2, respectively (see Figure 1).

[0029] In the manufacturing line, the lighting in the specific area RG1 is set to be dimmer than the lighting in the external area RG2 so that the mobile communication device 50 can identify entry into and exit from the specific area RG1. This setting results in the illuminance of the specific area RG1 being lower than that of the external area RG2.

[0030] The mobile communication device 50 periodically detects the illuminance on the work surface 10. The mobile communication device 50 compares the detected illuminance with a threshold TH that distinguishes between the illuminance of a specific area RG1 and the illuminance of an external area RG2, and determines whether the device has entered the specific area RG1 and whether it has exited the specific area RG1 (i.e., whether it has entered the external area RG2).

[0031] When the mobile communication device 50 determines that it has entered a specific area RG1, it switches its operating mode from low-power mode to normal mode and notifies the fixed communication device 80 of the transition to normal mode. When the mobile communication device 50 determines that it has left the specific area RG1 (i.e., entered an external area RG2), it notifies the fixed communication device 80 of the transition to low-power mode and switches its operating mode from normal mode to low-power mode. In normal mode, all functions of the mobile communication device 50 are available, while in low-power mode, some functions of the mobile communication device 50 are disabled. Thus, low-power mode is a mode that consumes less power than normal mode and is also called sleep mode.

[0032] Here, the mobile communication device 50 notifies the fixed communication device 80 of the transition to low-power mode after entering the external region RG2. Therefore, as shown in Figure 2, the mobile communication device 50 can wirelessly communicate with the fixed communication device within a predetermined range ER from the boundary BD between a specific region RG1 and the external region RG2, located downstream in the direction of movement of the work board 10, within the external region RG2. The length of the predetermined range ER in the direction of movement of the work board 10 is set to be at least greater than the distance the work board 10 moves in the time required for one cycle in which the mobile communication device 50 detects illuminance. With this setting, the mobile communication device 50 can detect illuminance at least once within the predetermined range ER.

[0033] Furthermore, the length of the specific region RG1 in the direction of movement of the work plate 10 is set to be at least greater than the distance the work plate 10 moves in the time required for one cycle in which the mobile communication device 50 detects illuminance. This setting allows the mobile communication device 50 to detect illuminance at least once within the specific region RG1.

[0034] When the fixed communication device 80 is notified by the mobile communication device 50 of a transition to normal mode, it transmits a transmission request signal to the mobile communication device 50. When the mobile communication device 50 receives the transmission request signal from the fixed communication device 80, it obtains the inspection results of the product to be manufactured from the inspection device 30 and transmits the manufacturing information of the product to the fixed communication device 80, including the obtained inspection results. When the fixed communication device 80 receives the manufacturing information of the product to be manufactured from the mobile communication device 50, it transmits the received manufacturing information to the management device 100.

[0035] [Configuration of the inspection device] The configurations of the inspection device 30, the mobile communication device 50, and the fixed communication device 80 will be described below in order. First, the configuration of the inspection device 30 will be described. Figure 5 is a block diagram showing an example of the configuration of the inspection device 30. As shown in Figure 5, the inspection device 30 comprises a receiving unit 31, a transmitting unit 33, a control unit 35, a storage unit 37, an input unit 39, a holding unit 41, and an inspection unit 43.

[0036] The receiving unit 31 receives a signal from the mobile communication device 50 via a communication line. This signal includes a transmission request signal requesting the transmission of the inspection results of the product to be manufactured.

[0037] The transmitting unit 33 transmits a signal to the mobile communication device 50 via a communication line. This signal includes the inspection results of the manufactured product. The functions of the receiving unit 31 and the transmitting unit 33 are also referred to as external interface functions.

[0038] The control unit 35 controls the entire process in the inspection device 30. Specifically, the control unit 35 controls the operation of each of the following: the receiving unit 31, the transmitting unit 33, the storage unit 37, the input unit 39, the holding unit 41, and the inspection unit 43. When the receiving unit 31 receives a transmission request signal, the control unit 35 causes the transmitting unit 33 to transmit information about the holding state of the holding unit 41, which will be described later, as the inspection result of the manufactured object.

[0039] The memory unit 37 stores various information necessary for the inspection device 30 to operate. The memory unit 37 also stores information about the holding state of the holding unit 41. The input unit 39 receives the start of inspection of the manufactured object from the operator at the inspection process IP.

[0040] The holding portion 41 holds a corresponding part among the five parts attached to the manufactured object. The holding portion 41 is configured to hold the corresponding part when it is attached to the manufactured object in the position and orientation specified in the product specifications.

[0041] The holding unit 41 has a built-in switch. When the input unit 39 receives a signal from the operator to begin inspection of the product to be manufactured, the switch is set to either the ON or OFF state. Specifically, the switch is ON when the holding unit 41 is holding a part. On the other hand, the switch is OFF when the holding unit 41 is not holding a part. The function of the holding unit 41 to hold a part is also referred to as the part holding function.

[0042] The inspection unit 43 inspects the mounting status of the corresponding component among the five components attached to the manufacturing object. Specifically, when the input unit 39 receives notification from the operator to start the inspection of the manufacturing object, the inspection unit 43 detects whether the switch on the holding unit 41 is in the ON or OFF state.

[0043] When the inspection unit 43 detects that the switch of the holding unit 41 is in the ON state, it sets the value "1" as information about the holding state of the holding unit 41 and stores it in the storage unit 37. The value "1" set as information about the holding state of the holding unit 41 indicates that the corresponding part is correctly attached to the manufacturing object.

[0044] On the other hand, when the inspection unit 43 detects that the switch of the holding unit 41 is in the off state, it sets the value "0" as information about the holding state of the holding unit 41 and stores it in the storage unit 37. The value "0" set as information about the holding state of the holding unit 41 indicates that the corresponding part is not properly attached to the manufacturing object. Note that the value set as information about the holding state of the holding unit 41 is not limited to "1" and "0", but may be any other value.

[0045] As described above, if a part is correctly attached to the workpiece, the holding part 41 can hold the part. On the other hand, if a part is not correctly attached to the workpiece, the holding part 41 cannot hold the part. For this reason, the expression "the inspection unit 43 inspects the mounting state of the corresponding part" can also be rephrased as "the inspection unit 43 inspects the holding state of the holding part 41." The function of the inspection unit 43 to inspect (detect) the mounting state of a part is also called the part detection function.

[0046] [Functional configuration of mobile communication devices] Next, the functional configuration of the mobile communication device 50 will be described. Figure 6 is a block diagram showing an example of the functional configuration of the mobile communication device 50. As shown in Figure 6, the mobile communication device 50 includes a receiving unit 51, a transmitting unit 53, a control unit 55, a storage unit 57, an input / output unit 59, a frame generation unit 61, a communication processing unit 63, an illumination detection unit 65, a determination unit 67, a switching unit 69, and an acquisition unit 71.

[0047] The receiving unit 51 receives radio signals from the fixed communication device 80. These radio signals include a transmission request signal, a reception completion signal, a first retransmission request signal, and a second retransmission request signal, which will be described later. The receiving unit 51 is also referred to as the first receiving unit.

[0048] The transmitting unit 53 transmits a radio signal to the fixed communication device 80. This radio signal includes a first notification signal, a second notification signal, and a manufacturing information signal, which will be described later. The first and second notification signals are transmitted using a random access method, as will be described later, and are performed within a time slot acquired at the time when transmission is required. The manufacturing information signal is transmitted using a reservation method, as will be described later, and is performed within a time slot allocated by the fixed communication device 80.

[0049] The transmitting unit that transmits the first notification signal and the second notification signal is also referred to as the first transmitting unit. The transmitting unit that transmits the manufacturing information signal is also referred to as the second transmitting unit. Furthermore, the functions of the receiving unit 51 and the transmitting unit 53 are collectively referred to as the wireless communication function.

[0050] The control unit 55 controls the entire process in the mobile communication device 50. Specifically, the control unit 55 controls the operation of each of the following: the receiving unit 51, the transmitting unit 53, the storage unit 57, the input / output unit 59, the frame generation unit 61, the communication processing unit 63, the illumination detection unit 65, the determination unit 67, the switching unit 69, and the acquisition unit 71.

[0051] The storage unit 57 stores various information necessary for the operation of the mobile communication device 50. The storage unit 57 stores the address of its own device and the address of the fixed communication device 80. The storage unit 57 stores a threshold TH that distinguishes the illuminance of a specific area RG1 from the illuminance of an external area RG2. The storage unit 57 stores time slot allocation information assigned by the fixed communication device 80. The storage unit 57 stores the comparison result between the illuminance detected by the illuminance detection unit 65 and the threshold TH. The storage unit 57 stores identification information assigned to the inspection device 30. The storage unit 57 stores the inspection results of the manufactured object (information on the holding state of the holding unit 41) acquired from the inspection device 30. The storage unit 57 stores the manufacturing information of the manufactured object generated by the acquisition unit 71.

[0052] The input / output unit 59 is connected to the inspection device 30 via a communication line for communication. The input / output unit 59 transmits a transmission request signal to the inspection device 30. In response to the transmission of the transmission request signal, the input / output unit 59 receives the inspection results of the manufactured object from the inspection device 30. The function of the input / output unit 49 is also referred to as the external interface function.

[0053] The frame generation unit 61 generates a communication frame when transmitting a wireless signal to the fixed communication device 80. Figure 14 is a diagram illustrating an example of the configuration of a communication frame. As shown in Figure 14, a communication frame consists of a preamble, a unique word, frame types FT1 to FT7, a source address, a destination address, data, and an FCS (Frame Check Sequence).

[0054] The preamble is a bit sequence for bit synchronization, used by the receiving device to synchronize with the communication frame bit by bit. The unique word is a bit sequence for frame synchronization, used by the receiving device to identify the starting position of subsequent information (frame type).

[0055] Figure 15 illustrates an example of communication frame types. As shown in Figure 15, frame types FT1 to FT7 indicate the type of communication frame. Specifically, frame type FT1 indicates that the communication frame is a first notification signal. Frame type FT2 indicates that the communication frame is a first retransmission request signal. Frame type FT3 indicates that the communication frame is a transmit request signal.

[0056] Frame type FT4 indicates that the communication frame is a second retransmission request signal. Frame type FT5 indicates that the communication frame is a manufacturing information signal. Frame type FT6 indicates that the communication frame is a second notification signal. Frame type FT7 indicates that the communication frame is a reception complete signal.

[0057] As described above, the transmitting unit 53 transmits the first notification signal, the second notification signal, and the manufacturing information signal. For this reason, the frame generation unit 61 generates communication frames of frame types FT1, FT5, and FT6.

[0058] The first notification signal is used to notify that the mobile communication device 50 has entered the inspection process IP (specific area RG1) and transitioned to normal mode. The second notification signal is used to notify that the device has exited the inspection process IP (specific area RG1) and transitioned to low power mode. The manufacturing information signal is used to transmit manufacturing information of the product being manufactured. The first notification signal, the second notification signal, and the manufacturing information signal are also referred to as the wake-up notification signal, sleep transition signal, and notification signal, respectively.

[0059] On the other hand, as described above, the receiving unit 51 receives a transmission request signal, a reception completion signal, a first retransmission request signal, and a second retransmission request signal. The transmission request signal is used by the fixed communication device 80 to request the transmission of manufacturing information of the product to be manufactured. The reception completion signal is used by the fixed communication device 80 to notify that it has received manufacturing information from all mobile communication devices 50 (50a to 50e) installed on the work board 10. The first retransmission request signal is used by the fixed communication device 80 to request the retransmission of the first notification signal. The second retransmission request signal is used by the fixed communication device 80 to request the retransmission of manufacturing information. The transmission request signal, reception completion signal, first retransmission request signal, and second retransmission request signal are also referred to as notification request signal, notification reception completion signal, wake-up notification retransmission request signal, and retransmission request signal, respectively.

[0060] The source address is information indicating the address of the sending device. The destination address is information indicating the address of the receiving device. The data is the information that should be sent to the receiving device.

[0061] Of the three communication frames generated by the frame generation unit 61, data is included only in the manufacturing information signal. In this case, the data included in the manufacturing information signal is the manufacturing information of the product being manufactured. In order to keep the size of the three communication frames constant, a predetermined number of dummy bits (for example, a sequence of 0 bits) may be inserted as data into the first notification signal and the second notification signal.

[0062] FCS is a bit sequence used by the receiving device to determine whether or not there is an error in the communication frame.

[0063] The communication processing unit 63 performs modulation processing to transmit various wireless signals on radio waves, demodulation processing to extract the various wireless signals transmitted on radio waves, and so on.

[0064] The illuminance detection unit 65 periodically detects the illuminance on the work surface 10. The illuminance detection unit 65 is, for example, a photosensor element such as a photoresistor, diode, or phototransistor. In this embodiment, the illuminance detection unit 65 is composed of a photoresistor. The function of the illuminance detection unit 65 is also referred to as the illuminance detection function.

[0065] The determination unit 67 compares the illuminance detected by the illuminance detection unit 65 with the threshold value TH stored in the storage unit 57 to determine whether the mobile communication device 50 has entered the specific area RG1 from the external area RG2, and whether it has entered the external area RG2 from the specific area RG1.

[0066] Specifically, the determination unit 67 determines that the mobile communication device 50 has entered the specific area RG1 from the external area RG2 if it determines that the illuminance detected by the illuminance detection unit 65 is below the threshold TH. More specifically, the determination unit 67 determines that the mobile communication device 50 has entered the specific area RG1 from the external area RG2 if it determines that the illuminance currently detected by the illuminance detection unit 65 is below the threshold TH, AND that the illuminance previously detected by the illuminance detection unit 65 exceeds the threshold TH.

[0067] On the other hand, if the determination unit 67 first determines that the illuminance detected by the illuminance detection unit 65 exceeds the threshold TH after entering the specific area RG1, it determines that the mobile communication device 50 has entered the external area RG2 from the specific area RG1. In other words, if the determination unit 67 determines that the illuminance currently detected by the illuminance detection unit 65 exceeds the threshold TH, and that the illuminance previously detected by the illuminance detection unit 65 was less than or equal to the threshold TH, it determines that the mobile communication device 50 has entered the external area RG2 from the specific area RG1.

[0068] The determination unit 67 stores the comparison result between the illuminance detected by the illuminance detection unit 65 and the threshold TH in the storage unit 57.

[0069] In this embodiment, the illuminance detection function of the illuminance detection unit 65 and the comparison function of the determination unit 67 are composed of a detection circuit 213 (see Figure 7). Figure 8 is a circuit diagram showing an example of the detection circuit 213. As shown in Figure 8, the detection circuit 213 comprises resistors 213a to 213c, a photoresistor 213d, and a comparator 213e.

[0070] Resistor 213a has one end connected to the power supply voltage Vcc and the other end connected to the photoresistor 213d. Photoresistor 213d has one end connected to resistor 213a and the other end connected to ground. Detection circuit 213 divides the power supply voltage Vcc using the resistance value R1 of resistor 213a and the resistance value Rc of photoresistor 213d to generate an illuminance signal (input voltage) Vin.

[0071] Resistor 213b has one end connected to the power supply voltage Vcc and the other end connected to resistor 213c. Resistor 213c has one end connected to resistor 213b and the other end connected to ground. The detection circuit 213 divides the power supply voltage Vcc using the resistance value R2 of resistor 213b and the resistance value R3 of resistor 213c to generate a reference signal (reference voltage) Vref.

[0072] The comparator 213e receives the illuminance signal Vin and the reference signal Vref as inputs, and outputs the result of comparing the illuminance signal Vin and the reference signal Vref as a judgment signal (output voltage) Vout. The judgment signal Vout is also called the inspection process detection signal Vwake.

[0073] Figure 9 shows an example of the characteristics of the photoresistor 213d used in the detection circuit 213. Figure 10 is a diagram illustrating the setting of the threshold TH used in the detection circuit 213. As shown in Figure 9, the resistance value Rc of the photoresistor 213d increases as the illuminance decreases. Therefore, as shown in Figure 10, the illuminance signal Vin increases as the illuminance decreases.

[0074] For example, if the illuminance of a specific region RG1 is set to be 100 lx or less, and the illuminance of the external region RG2 is set to be greater than 100 lx, then 100 lx is set as the threshold TH that distinguishes between the illuminance of the specific region RG1 and the illuminance of the external region RG2. In this case, as shown in Figure 10, the illuminance signal Vin corresponding to the threshold TH (100 lx) becomes 0.5 × Vcc. Therefore, the ratio of the resistance value R2 of resistor 213b and the resistance value R3 of resistor 213c is adjusted so that the reference signal Vref becomes 0.5 × Vcc.

[0075] As a result, when the illuminance on the work surface 10 is 100 lx or less, the illuminance signal Vin will be 0.5 × Vcc or greater, so the comparator 213e outputs HIGH as the judgment signal Vout. On the other hand, when the illuminance on the work surface 10 exceeds 100 lx, the illuminance signal Vin will be less than 0.5 × Vcc, so the comparator 213e outputs LOW as the judgment signal Vout.

[0076] The determination unit 67 determines that the mobile communication device 50 has entered the specific area RG1 from the external area RG2 if the determination signal Vout is HIGH. On the other hand, the determination unit 67 determines that the mobile communication device 50 has entered the external area RG2 from the specific area RG1 if the determination signal Vout is LOW.

[0077] In this case, if the illuminance detection unit 65 detects the illuminance on the work board 10 two or more times in the specific area RG1, the determination unit 67 determines that the mobile communication device 50 has entered the specific area RG1 from the external area RG2 if the determination signal Vout output this time is HIGH and the determination signal Vout output last time was LOW.

[0078] Similarly, in the external region RG2, if the illuminance detection unit 65 detects illuminance on the work board 10 two or more times, the determination unit 67 determines that the mobile communication device 50 has entered the external region RG2 from the specific region RG1 if the determination signal Vout output this time is LOW and the determination signal Vout output last time was HIGH.

[0079] The determination unit 67 determines whether the receiving unit 51 has received the first retransmission request signal. If the determination unit 67 determines that the receiving unit 51 has received the first retransmission request signal, the control unit 55 causes the transmitting unit 53 to retransmit the first notification signal.

[0080] The determination unit 67 determines whether the receiving unit 51 has received a transmission request signal. If the determination unit 67 determines that the receiving unit 51 has received a transmission request signal, the control unit 55, as described later, causes the acquisition unit 71 to acquire information on the holding state of the holding unit 41 as an inspection result of the manufactured object, and causes the transmission unit 53 to transmit a manufacturing information signal.

[0081] The determination unit 67 determines whether the receiving unit 51 has received the second retransmission request signal. If the determination unit 67 determines that the receiving unit 51 has received the second retransmission request signal, the control unit 55 causes the transmitting unit 53 to retransmit the manufacturing information signal.

[0082] The switching unit 69 switches the operating mode of the mobile communication device 50 from low power consumption mode to normal mode when the determination unit 67 determines that the mobile communication device 50 has entered the specific area RG1 from the external area RG2. On the other hand, the switching unit 69 switches the operating mode of the mobile communication device 50 from normal mode to low power consumption mode when the determination unit 67 determines that the mobile communication device 50 has entered the external area RG2 from the specific area RG1.

[0083] In low-power mode, the operation of the receiving unit 51, transmitting unit 53, input / output unit 59, frame generation unit 61, communication processing unit 63, and acquisition unit 71 is stopped. As a result, the mobile communication device 50 can reduce the power consumption required to operate these functions in the external region RG2. The function of the switching unit 69 is also referred to as the operating mode control function.

[0084] The acquisition unit 71 acquires information on the holding state of the holding unit 41 as an inspection result of the manufacturing target from the inspection device 30, and generates manufacturing information of the manufacturing target including the acquired inspection result. Specifically, the acquisition unit 71 transmits a transmission request signal to the inspection device 30 via the input / output unit 59. The acquisition unit 71 acquires information on the holding state of the holding unit 41 as an inspection result of the manufacturing target via the input / output unit 59. The acquisition unit 71 stores the acquired information on the holding state of the holding unit 41 in the storage unit 57.

[0085] When the acquisition unit 71 acquires information on the holding state of the holding unit 41, it links the identification information of the inspection device 30 with the information on the holding state of the holding unit 41 to generate manufacturing information for the manufactured object. The acquisition unit 71 stores the generated manufacturing information for the manufactured object in the storage unit 57. The function of the acquisition unit 71 is also referred to as the part detection function.

[0086] Figure 11 illustrates an example of identification information assigned to the inspection device 30. As shown in Figure 11, in this embodiment, each of the inspection devices 30a to 30e is pre-assigned identification information ID1 to ID5. The storage unit 57 pre-stores the identification information ID1 to ID5 associated with the inspection devices 30a to 30e.

[0087] Figure 12 illustrates an example of an inspection result of a manufactured object acquired by the acquisition unit 71. If the corresponding part is correctly attached to the manufactured object, the acquisition unit 71 acquires information on the holding state of the holding part 41, which is set to a value of "1", from the inspection device 30 as an inspection result of the manufactured object. On the other hand, if the corresponding part is not correctly attached to the manufactured object, the acquisition unit 71 acquires information on the holding state of the holding part 41, which is set to a value of "0", from the inspection device 30 as an inspection result of the manufactured object.

[0088] [Hardware configuration of mobile communication devices] Next, the hardware configuration of the mobile communication device 50 will be described. Figure 7 is a block diagram showing an example of the hardware configuration of the mobile communication device 50. As shown in Figure 7, the mobile communication device 50 is composed of a computer and includes a CPU (Central Processing Unit) 201, ROM (Read Only Memory) 203, RAM (Random Access Memory) 205, storage 207, antenna 209, transmit / receive circuit 211, detection circuit 213, and external interface 215.

[0089] The CPU 201 executes the program stored in the ROM 203. According to this program, the CPU 201 performs calculations on the data loaded into the RAM 205 and comprehensively controls each part of the mobile communication device 50. The CPU is also referred to as a processor.

[0090] ROM203 stores programs executed by CPU201. In this embodiment, ROM203 stores at least a program for controlling the operation flow of the mobile communication device 50, which will be described later. RAM205 temporarily holds calculation data when CPU201 executes a program stored in ROM203. ROM203 and RAM205 are also referred to as non-volatile memory and volatile memory, respectively.

[0091] The storage device 207 stores control parameters necessary for the operation of the mobile communication device 50, various information necessary for the operation flow of the mobile communication device 50, and so on. The CPU 201 controls the reading and writing of data to the storage device 207 according to the program stored in the ROM 203. The storage device 207 may be, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive), and both an HDD and an SSD may be used as the storage device 207. In addition, the storage device 207 may be provided outside the mobile communication device 50 as a database.

[0092] Antenna 209 transmits or receives radio waves under the control of CPU 201. Transmitting / receiving circuit 211 performs the above-mentioned modulation and demodulation processes under the control of CPU 201. Detection circuit 213 performs the above-mentioned illuminance detection and comparison of the detected illuminance with the threshold TH under the control of CPU 201.

[0093] The external interface 215 is connected to the inspection device 30. The CPU 201 transmits and receives signals to and from the inspection device 30 via the external interface 215.

[0094] [Functional configuration of fixed communication equipment] Next, the functional configuration of the fixed communication device 80 will be described. Figure 13 is a block diagram showing an example of the functional configuration of the fixed communication device 80. As shown in Figure 13, the fixed communication device 80 includes a receiving unit 81, a transmitting unit 83, a control unit 85, a storage unit 87, an input / output unit 89, a frame generation unit 91, a communication processing unit 93, a determination unit 95, and an allocation unit 97.

[0095] The receiving unit 81 receives radio signals from each of the multiple mobile communication devices 50 (50a to 50e) installed on the work board 10. These radio signals include a first notification signal, a second notification signal, and a manufacturing information signal. The receiving unit 81 that receives the first and second notification signals is also referred to as the second receiving unit. The receiving unit 81 that receives the manufacturing information signal is also referred to as the third receiving unit.

[0096] The transmitting unit 83 transmits a radio signal to each of the multiple mobile communication devices 50 (50a to 50e) installed on the work board 10. The transmitting unit 83 broadcasts the radio signal to the multiple mobile communication devices 50 (50a to 50e) installed on the work board 10. The radio signals to be broadcast include a transmission request signal, a reception completion signal, a first retransmission request signal, and a second retransmission request signal. The broadcasting of the transmission request signal, reception completion signal, first retransmission request signal, and second retransmission request signal is performed using a random access method, as will be described later, within a time slot acquired at the timing when transmission is required.

[0097] The transmitting unit that broadcasts the transmission request signal, the first retransmission request signal, and the second retransmission request signal is also referred to as the third transmitting unit. Furthermore, the functions of the receiving unit 81 and the transmitting unit 83 are collectively referred to as the wireless communication function.

[0098] The control unit 85 controls the entire process in the fixed communication device 80. Specifically, the control unit 85 controls the operation of each of the following: the receiving unit 81, the transmitting unit 83, the storage unit 87, the input / output unit 89, the frame generation unit 91, the communication processing unit 93, the determination unit 95, and the allocation unit 97. When the receiving unit 81 receives a manufacturing information signal, the control unit 85 causes the input / output unit 89 to transmit the manufacturing information of the manufacturing target contained in the received manufacturing information signal.

[0099] The memory unit 87 stores various information necessary for the operation of the fixed communication device 80. The memory unit 87 stores the address of the device itself, the addresses of the multiple mobile communication devices 50 (50a to 50e) installed on the work board 10, and the broadcast address. The memory unit 87 stores information on the time slots used by each mobile communication device 50 to transmit manufacturing information signals. The memory unit 87 stores information on the mobile communication device 50 that transmitted the first notification signal. The memory unit 87 stores information on the mobile communication device 50 that transmitted the second notification signal. The memory unit 87 stores information on the mobile communication device 50 that transmitted the manufacturing information signal.

[0100] The input / output unit 89 is connected to the management device 100 via a communication line for communication. The input / output unit 89 transmits manufacturing information of the product to the management device 100. The input / output unit 89 also transmits an abnormality signal to the management device 100. The input / output unit 89 is also referred to as the fourth transmission unit. The function of the input / output unit 49 is also referred to as the external interface function.

[0101] The frame generation unit 91 generates communication frames when transmitting radio signals to each mobile communication device 50 and when broadcasting radio signals to multiple mobile communication devices 50 (50a to 50e). As described above, the communication frame consists of a preamble, a unique word, frame types FT1 to FT7, a source address, a destination address, data, and FCS (see Figure 14).

[0102] As described above, the transmitting unit 83 broadcasts a transmission request signal, a reception completion signal, a first retransmission request signal, and a second retransmission request signal. For this reason, the frame generation unit 91 generates communication frames of frame types FT2, FT3, FT4, and FT7.

[0103] When the frame generation unit 91 broadcasts a radio signal to multiple mobile communication devices 50 (50a to 50e), it sets the destination address of the communication frame to the broadcast address. Of the four communication frames generated by the frame generation unit 91, data is included only in the transmission request signal and the second retransmission request signal. In this case, the data included in the transmission request signal and the second retransmission request signal is the allocation information of the time slot used by each mobile communication device 50 to transmit the manufacturing information signal. In order to keep the size of the four communication frames constant, a predetermined number of dummy bits (for example, a sequence of 0 bits) may be inserted as data in the reception completion signal and the first retransmission request signal.

[0104] The communication processing unit 93 performs modulation processing to transmit various wireless signals on radio waves, demodulation processing to extract the various wireless signals transmitted on radio waves, and so on.

[0105] The determination unit 95 determines whether the receiving unit 81 has received a first notification signal from all of the mobile communication devices 50 (50a to 50e) installed on the work board 10. If the determination unit 95 determines that the receiving unit 81 has received a first notification signal from all of the mobile communication devices 50 (50a to 50e), the control unit 85 causes the transmitting unit 83 to notify a transmission request signal.

[0106] If the determination unit 95 determines that the receiving unit 81 has not received the first notification signal from any of the mobile communication devices 50 (50a to 50e), the control unit 85 causes the transmitting unit 83 to notify the first retransmission request signal after the first period has elapsed.

[0107] The determination unit 95 determines whether the receiving unit 81 has received manufacturing information signals from all mobile communication devices 50 (50a to 50e) installed on the work board 10. If the determination unit 95 determines that the receiving unit 81 has received manufacturing information signals from all mobile communication devices 50 (50a to 50e), the control unit 85 causes the transmission unit 83 to notify the transmission unit 83 of the reception completion signal.

[0108] If the determination unit 95 determines that the receiving unit 81 has not received manufacturing information signals from all mobile communication devices 50 (50a to 50e), it determines whether the receiving unit 81 has received a second notification signal from all mobile communication devices 50 (50a to 50e). If the determination unit 95 determines that the receiving unit 81 has received a second notification signal from all mobile communication devices 50 (50a to 50e), the control unit 85 causes the input / output unit 89 to transmit an abnormality signal.

[0109] If the determination unit 95 determines that the receiving unit 81 has not received the second notification signal from any of the mobile communication devices 50 (50a to 50e), the control unit 85 will cause the transmitting unit 83 to notify the second retransmission request signal after the second period has elapsed.

[0110] Furthermore, even if the determination unit 95 determines that the receiving unit 81 has not received a second notification signal from any of the mobile communication devices 50 (50a to 50e), if a time has elapsed that exceeds the time required for the work board 10 to pass through the specific area RG1, the control unit 85 will cause the input / output unit 89 to transmit an abnormality signal.

[0111] Furthermore, even if the determination unit 95 determines that the receiving unit 81 has not received a second notification signal from any of the mobile communication devices 50 (50a to 50e), if a predetermined amount of time has elapsed since the previous second notification signal was received, the control unit 85 may cause the input / output unit 89 to transmit an abnormality signal.

[0112] The allocation unit 97 allocates time slots used for transmitting manufacturing information signals to multiple mobile communication devices 50 (50a to 50e), generates time slot allocation information, and stores it in the storage unit 87. The allocation unit 97 allocates time slots to each mobile communication device 50 in the order in which they enter the specific area RG1. The time slots allocated to the mobile communication devices 50 are also referred to as transmission timings.

[0113] Specifically, the allocation unit 97 allocates time slots to each mobile communication device 50 based on the order in which the receiving unit 81 received the first notification signal. The allocation unit 97 may also allocate time slots to each mobile communication device 50 in order, starting with the mobile communication device 50 located downstream in the direction of movement of the work board 10, based on the arrangement position of the mobile communication devices 50 along the direction of movement of the work board 10.

[0114] [Hardware configuration of fixed communication equipment] Next, the hardware configuration of the fixed communication device 80 will be described. The hardware configuration of the fixed communication device 80 is composed of a computer and includes a CPU, ROM, RAM, storage, antenna, transmitting and receiving circuit, and external interface. Thus, the hardware configuration of the fixed communication device 80 is the same as that of the mobile communication device 50, except for the detection circuit 213, so the explanation will be omitted.

[0115] The configurations of the inspection device 30, the mobile communication device 50, and the fixed communication device 80 have been described in order above.

[0116] [Example of a g sequence] Next, an example of a communication sequence in the wireless communication system 5 will be described. Figure 16 is a diagram illustrating an example of a communication sequence. As shown in Figure 16, in the wireless communication system 5, wireless communication using Time Division Multiple Access (TDMA) is performed between the mobile communication devices 50a to 50e and the fixed communication device 80.

[0117] Specifically, in the wireless communication system 5, one wireless channel is divided into multiple TDMA frames at regular time intervals. Each TDMA frame is divided into multiple time slots. In each TDMA frame, the multiple time slots are classified into a first time slot group in which wireless signals are transmitted from mobile communication devices 50a to 50e to the fixed communication device 80, and a second time slot group in which wireless signals are transmitted from the fixed communication device 80 to the mobile communication devices 50a to 50e.

[0118] In this embodiment, the first time slot group consists of five time slots TU1 to TU5. The second time slot group consists of one time slot TD. The first time slot group and the second slot group are arranged alternately along the time axis.

[0119] Each of the mobile communication devices 50a to 50e transmits a first notification signal and a second notification signal to the fixed communication device 80 using a random access method. Specifically, each of the mobile communication devices 50a to 50e acquires one time slot within the first time slot group when it is necessary to transmit either the first notification signal or the second notification signal. Within the time slot it has acquired, each of the mobile communication devices 50a to 50e transmits either the first notification signal or the second notification signal to the fixed communication device 80.

[0120] Each of the mobile communication devices 50a to 50e transmits a manufacturing information signal to the fixed communication device 80 using a reservation system. Specifically, each of the mobile communication devices 50a to 50e transmits a manufacturing information signal to the fixed communication device 80 within one time slot within the first time slot group allocated by the fixed communication device 80.

[0121] The fixed communication device 80 broadcasts a transmission request signal, a reception completion signal, a first retransmission request signal, and a second retransmission request signal using a random access method. Specifically, the fixed communication device 80 acquires one time slot within the second time slot group when it is necessary to broadcast a transmission request signal, a reception completion signal, a first retransmission request signal, or a second retransmission request signal. Within the acquired time slot, the fixed communication device 80 broadcasts a transmission request signal, a reception completion signal, a first retransmission request signal, or a second retransmission request signal.

[0122] In the example shown in Figure 16, each of the mobile communication devices 50a to 50e acquires one time slot within the first time slot group to notify the fixed communication device 80 that it has transitioned to normal mode when it enters a specific area RG1. Each of the mobile communication devices 50a to 50e transmits a first notification signal to the fixed communication device 80 within the time slot it has acquired.

[0123] Specifically, as the work board 10 moves, each mobile communication device 50a to 50e enters a specific area RG1 in sequence and acquires time slots TU1 to TU5. Within each of the time slots TU1 to TU5, each mobile communication device 50a to 50e transmits a first notification signal.

[0124] When the fixed communication device 80 receives the first notification signals sequentially from the mobile communication devices 50a to 50e, it acquires a time slot TD and broadcasts a transmission request signal. The transmission request signal includes time slot allocation information assigned to the mobile communication devices 50a to 50e by the fixed communication device 80 based on the order in which the first notification signals were received.

[0125] When each of the mobile communication devices 50a to 50e receives a transmission request signal, it refers to the time slot allocation information and transmits a manufacturing information signal to the fixed communication device 80 within the time slots TU1 to TU5 allocated by the fixed communication device 80.

[0126] When the fixed communication device 80 receives manufacturing information signals sequentially from the mobile communication devices 50a to 50e, it acquires a time slot TD and broadcasts a reception completion signal.

[0127] [Example of mobile communication device operation] Next, an example of the operation of the mobile communication device 50 will be described. Specifically, an example of the operation of the mobile communication device 50 from the time it enters a specific area RG1 until it exits the specific area RG1 will be described. Figures 17A and 17B are diagrams showing an example of the operation flowchart of the mobile communication device 50.

[0128] When the operator activates the mobile communication device 50, the mobile communication device 50 operates in normal mode and performs initial settings such as wireless communication parameters (e.g., wireless communication channel, transmission power, etc.) and input ports. Once the initial settings are complete, the mobile communication device 50 switches its operating mode from normal mode to low power consumption mode and begins to periodically detect the illuminance on the work surface 10.

[0129] As shown in Figure 17A, the mobile communication device 50 compares the detected illuminance with the threshold TH to determine whether the detected illuminance is less than or equal to the threshold TH (step S11). If the mobile communication device 50 determines that the detected illuminance is not less than or equal to the threshold TH, it detects the illuminance on the work board 10 after a predetermined time has elapsed and returns to step S11.

[0130] On the other hand, if the mobile communication device 50 determines that the detected illuminance is below the threshold TH, it determines that it has entered the specific area RG1 from the external area RG2 and switches the operating mode from low power consumption mode to normal mode (step S13).

[0131] When the mobile communication device 50 switches its operating mode to normal mode, it transmits a first notification signal to the fixed communication device 80 using a random access method to notify the fixed communication device 80 of the transition to normal mode (step S15).

[0132] When the mobile communication device 50 transmits the first notification signal, it determines whether or not it has received the first retransmission request signal from the fixed communication device 80 (step S17). Specifically, when the mobile communication device 50 receives a radio signal, it checks the source address and frame type included in the radio signal. If the source address and frame type are the address and frame type FT2 of the fixed communication device 80, respectively, the mobile communication device 50 determines that it has received the first retransmission request signal from the fixed communication device 80.

[0133] If the mobile communication device 50 determines that it has received the first retransmission request signal from the fixed communication device 80, it returns to step S15. On the other hand, if the mobile communication device 50 determines that it has not received the first retransmission request signal from the fixed communication device 80, it determines whether or not it has received a transmission request signal from the fixed communication device 80 (step S19).

[0134] Specifically, when the mobile communication device 50 receives a radio signal, it checks the source address and frame type included in the radio signal. If the source address and frame type are the address and frame type FT3 of the fixed communication device 80, respectively, the mobile communication device 50 determines that it has received a transmission request signal from the fixed communication device 80.

[0135] If the mobile communication device 50 determines that it has not received a transmission request signal from the fixed communication device 80, it determines whether the detected illuminance exceeds the threshold TH (step S21).

[0136] If the mobile communication device 50 determines that the detected illuminance does not exceed the threshold TH, it returns to step S17. On the other hand, if the mobile communication device 50 determines that the detected illuminance exceeds the threshold TH, it determines that it has entered the external area RG2 from the specific area RG1 and transmits a second notification signal to the fixed communication device 80 (step S35). If the mobile communication device 50 has not detected any new illuminance, it omits step 21 and returns to step S17.

[0137] On the other hand, when the mobile communication device 50 determines that it has received a transmission request signal from the fixed communication device 80, it obtains information on the holding state of the holding unit 41 from the inspection device 30 as an inspection result of the product to be manufactured, and links the identification information of the inspection device 30 with the information on the holding state of the holding unit 41 to generate manufacturing information for the product to be manufactured (step S23).

[0138] Here, the time from when the work board 10 enters the specific area RG1 until the mobile communication device 50 transmits a transmission request signal to the inspection device 30 is set to be longer than the average time it takes for an operator to hold the corresponding part of the five parts attached to the workpiece in the holding unit 41.

[0139] As shown in Figure 17B, the mobile communication device 50 generates manufacturing information for the product to be manufactured (step S23), and then identifies the time slot allocated to itself by referring to the time slot allocation information included in the transmission request signal. Within the identified time slot, the mobile communication device 50 transmits a manufacturing information signal containing the manufacturing information for the product to the fixed communication device 80 (step S25). After transmitting the manufacturing information signal to the fixed communication device 80, the mobile communication device 50 determines whether or not it has received a second retransmission request signal from the fixed communication device 80 (step S27).

[0140] Specifically, when the mobile communication device 50 receives a radio signal, it checks the source address and frame type included in the radio signal. If the source address and frame type are the address and frame type FT4 of the fixed communication device 80, respectively, the mobile communication device 50 determines that it has received a second retransmission request signal from the fixed communication device 80.

[0141] If the mobile communication device 50 determines that it has received a second retransmission request signal from the fixed communication device 80, it returns to step S25. On the other hand, if the mobile communication device 50 determines that it has not received a second retransmission request signal from the fixed communication device 80, it determines whether or not it has received a reception completion signal from the fixed communication device 80 (step S29).

[0142] Specifically, when the mobile communication device 50 receives a radio signal, it checks the source address and frame type included in the radio signal. If the source address and frame type are the address and frame type FT7 of the fixed communication device 80, respectively, the mobile communication device 50 determines that it has received a reception completion signal from the fixed communication device 80.

[0143] If the mobile communication device 50 determines that it has not received a reception completion signal from the fixed communication device 80, it determines whether the detected illuminance exceeds the threshold TH (step S31).

[0144] If the mobile communication device 50 determines that the detected illuminance does not exceed the threshold TH, it returns to step S27. On the other hand, if the mobile communication device 50 determines that the detected illuminance exceeds the threshold TH, it determines that it has entered the external area RG2 from the specific area RG1 and transmits a second notification signal to the fixed communication device 80 (step S35). If the mobile communication device 50 has not detected any new illuminance, it omits step S31 and returns to step S27.

[0145] On the other hand, when the mobile communication device 50 determines that it has received a transmission request signal from the fixed communication device 80, it detects a new illuminance on the work board 10 and determines whether the detected illuminance exceeds the threshold TH (step S33). If the mobile communication device 50 determines that the detected illuminance does not exceed the threshold TH, it detects the illuminance on the work board 10 after a predetermined time has elapsed and returns to step S33. On the other hand, if the mobile communication device 50 determines that the detected illuminance exceeds the threshold TH, it determines that it has entered the external area RG2 from the specific area RG1 and transmits a second notification signal to the fixed communication device 80 (step S35).

[0146] When the mobile communication device 50 transmits the second notification signal, it switches its operating mode from normal mode to low power consumption mode (step S37). When the mobile communication device 50 switches its operating mode to low power consumption mode, it stops the operation of the receiving unit 51, transmitting unit 53, input / output unit 59, frame generation unit 61, communication processing unit 63, and acquisition unit 71.

[0147] [Example of fixed communication device operation] Next, an example of the operation of the fixed communication device 80 will be described. Figure 18 is a diagram showing an example of the operation flowchart of the fixed communication device 80. Specifically, an example of the operation of the fixed communication device 80 will be described from the time the mobile communication device 50 enters the specific area RG1 until it exits the specific area RG1.

[0148] When the operator starts the fixed communication device 80, the fixed communication device 80 performs initial settings such as wireless communication parameters (e.g., wireless communication channel, transmit power, etc.) and input port. Once the mobile communication device 50 has completed its initial settings, it enters a state of waiting to receive the first notification signal from the mobile communication device 50.

[0149] As shown in Figure 18, when the fixed communication device 80 receives the first notification signal from the mobile communication device 50 (step S51), it determines whether or not it has received the first notification signal from all of the mobile communication devices 50 (50a to 50e) installed on the work board 10 (step S53).

[0150] Specifically, each time the fixed communication device 80 receives a radio signal, it checks the source address and frame type contained in the radio signal. If the source address and frame type are the address and frame type FT1 of the mobile communication device 50, respectively, the fixed communication device 80 determines that it has received the first notification signal from the mobile communication device 50. Based on this, the fixed communication device 80 determines whether or not it has received the first notification signal from all of the mobile communication devices 50 (50a to 50e).

[0151] If the fixed communication device 80 determines that it has not received the first notification signal from any of the mobile communication devices 50 (50a to 50e), it determines whether the first period has elapsed (step S55). If the fixed communication device 80 determines that the first period has elapsed, it transmits (notifies) the first retransmission request signal (step S57) and returns to step S53. On the other hand, if the fixed communication device 80 determines that the first period has not elapsed, it returns to step S53. The first period is a time shorter than the time it takes for the work board 10 to pass through the specific area RG1.

[0152] Meanwhile, if the fixed communication device 80 determines that it has received the first notification signal from all mobile communication devices 50 (50a to 50e), it determines that the work board 10 has entered a specific area RG1. The fixed communication device 80 assigns time slots to all mobile communication devices 50 to be used for transmitting manufacturing information signals and generates time slot assignment information. The fixed communication device 80 transmits (notifies) a transmission request signal containing the time slot assignment information (step S59).

[0153] Note that the process in step S55 may be performed before the process in step S53. In this case, if the fixed communication device 80 determines that the first period has elapsed, it performs the process in step S53. On the other hand, if the fixed communication device 80 determines that the first period has not elapsed, it repeats the process in step S55.

[0154] After transmitting a transmission request signal, the fixed communication device 80 receives manufacturing information signals from each mobile communication device 50 and obtains manufacturing information for the product being manufactured from the manufacturing information signals. The fixed communication device 80 then transmits the obtained manufacturing information to the management device 100.

[0155] The management device 100 manages manufacturing information for each manufactured product. Specifically, the management device 100 obtains identification information for the inspection device 30 and information on the holding status of the holding unit 41 from the manufacturing information of the manufactured product transmitted from the fixed communication device 80. The management device 100 has pre-stored a table that links the identification information of the inspection device 30 with the part of the manufactured product that the inspection device 30 inspects. The management device 100 refers to this table to manage whether the parts are correctly attached to each part of the manufactured product.

[0156] When the fixed communication device 80 transmits a transmission request signal (step S59), it determines whether or not it has received manufacturing information signals from all mobile communication devices 50 (50a to 50e) (step S61).

[0157] Specifically, each time the fixed communication device 80 receives a radio signal, it checks the source address and frame type contained in the radio signal. If the source address and frame type are the address and frame type FT5 of the mobile communication device 50, respectively, the fixed communication device 80 determines that it has received a manufacturing information signal from the mobile communication device 50. This allows the fixed communication device 80 to determine whether or not it has received a manufacturing information signal from all of the mobile communication devices 50 (50a to 50e).

[0158] If the fixed communication device 80 determines that it has not received any manufacturing information signals from any of the mobile communication devices 50 (50a to 50e), it determines whether or not it has received a second notification signal from any of the mobile communication devices 50 (50a to 50e) (step S63).

[0159] Specifically, each time the fixed communication device 80 receives a radio signal, it checks the source address and frame type contained in the radio signal. If the source address and frame type are the address and frame type FT6 of the mobile communication device 50, respectively, the fixed communication device 80 determines that it has received a second notification signal from the mobile communication device 50. Based on this, the fixed communication device 80 determines whether or not it has received a second notification signal from all of the mobile communication devices 50 (50a to 50e).

[0160] When the fixed communication device 80 determines that it has received a second notification signal from all mobile communication devices 50 (50a to 50e), it determines that the work board 10 has exited into the specific area RG1. Since the fixed communication device 80 has not received a manufacturing information signal from all mobile communication devices 50 (50a to 50e), it transmits an abnormality signal to the management device 100 (step S65).

[0161] On the other hand, if the fixed communication device 80 determines that it has not received a second notification signal from any of the mobile communication devices 50 (50a to 50e), it determines whether the second period has elapsed (step S67). If the fixed communication device 80 determines that the second period has elapsed, it transmits (notifies) a second retransmission request signal (step S69) and returns to step S61. On the other hand, if the fixed communication device 80 determines that the second period has not elapsed, it returns to step S61. The second period is a shorter time than the time it takes for the work board 10 to pass through the specific area RG1.

[0162] Even if the fixed communication device 80 determines that it has not received a second notification signal from any of the mobile communication devices 50 (50a to 50e), if the time elapsed since the first receipt of the first notification signal in step S51 exceeds the time it takes for the work board 10 to pass through the specific area RG1, it determines that the work board 10 has exited the specific area RG1 and proceeds to step S65. The time exceeding the time it takes for the work board 10 to pass through the specific area RG1 is also referred to as the third period.

[0163] Furthermore, even if the fixed communication device 80 determines that it has not received a second notification signal from any of the mobile communication devices 50 (50a to 50e), it may proceed to step S65 if a predetermined amount of time has elapsed since it received the previous second notification signal.

[0164] On the other hand, if the fixed communication device 80 determines that it has received manufacturing information signals from all mobile communication devices 50 (50a to 50e), it transmits (notifies) a reception completion signal (step S71).

[0165] Note that the process in step S67 may be performed before the process in step S61. In this case, if the fixed communication device 80 determines that the second period has elapsed, it performs the process in step S61. On the other hand, if the fixed communication device 80 determines that the second period has not elapsed, it repeats the process in step S67.

[0166] [Effects / Effects] According to this embodiment, the mobile communication device 50 is attached to a work board 10 that moves along the transport path of the manufacturing line, and comprises a receiving unit 51, a transmitting unit 53, a storage unit 57, an illuminance detection unit 65, a determination unit 67, a switching unit 69, and an acquisition unit 71. The storage unit 57 stores a threshold TH that distinguishes between the illuminance of a specific area RG1 that can be wirelessly communicated with a fixed communication device 80 located outside the manufacturing line, and the illuminance of an external area RG2 other than the specific area RG1.

[0167] The illuminance detection unit 65 periodically detects the illuminance on the work surface 10. The determination unit 67 compares the illuminance detected by the illuminance detection unit 65 with a threshold TH to determine whether the mobile communication device 50 has entered the specific area RG1 from the external area RG2, and whether it has entered the external area RG2 from the specific area RG1. If the determination unit 67 determines that the mobile communication device 50 has entered the specific area RG1, the switching unit 69 switches the operating mode of the mobile communication device 50 from low power consumption mode to normal mode.

[0168] When the operating mode switches to normal mode, the transmitting unit 53 transmits a first notification signal to the fixed communication device 80 to notify the transition to normal mode. In response to the transmission of the first notification signal, the receiving unit 51 receives a transmission request signal from the fixed communication device 80. In response to the receipt of the transmission request signal, the acquisition unit 71 acquires information about the manufacturing object placed on the work board 10. The transmitting unit 53 transmits the manufacturing object information acquired by the acquisition unit 71 to the fixed communication device 80.

[0169] The mobile communication device 50 can wirelessly communicate with the fixed communication device 80 within a predetermined range ER from the boundary BD between a specific area RG1 and the external area RG2, located downstream in the direction of movement of the work board 10, in the external area RG2. When the determination unit 67 determines that the mobile communication device 50 has entered the external area RG2, the transmission unit 53 transmits a second notification signal to the fixed communication device 80 to notify it of a transition to low power consumption mode. When the transmission unit 53 transmits the second notification signal, the switching unit 69 switches the operating mode of the mobile communication device 50 from normal mode to low power consumption mode. In low power consumption mode, the operation of the receiving unit 51, the transmission unit 53, and the acquisition unit 71 is stopped.

[0170] With the above configuration, when the mobile communication device 50 enters a specific area RG1 where it can communicate wirelessly with the fixed communication device 80, the operating mode of the mobile communication device 50 switches from low power consumption mode to normal mode, and when it exits the specific area RG1, the operating mode of the mobile communication device 50 switches from normal mode to low power consumption mode. In low power consumption mode, the mobile communication device 50 stops the operation of the receiving unit 51, the transmitting unit 53, and the acquisition unit 71.

[0171] Thus, the mobile communication device 50 does not maintain a state where it can receive transmission request signals from the fixed communication device 80 in the external region RG2 other than the specific region RG1. Furthermore, since the mobile communication device 50 transmits information about the product to be manufactured only when it receives a transmission request signal from the fixed communication device 80, it does not transmit information about the product to be manufactured in the external region RG2. As a result, the power consumption of the mobile communication device 50 can be reduced.

[0172] Furthermore, with the above configuration, when the fixed communication device 80 receives a first notification signal from the mobile communication device 50, it transmits a transmission request signal to the mobile communication device 50 to obtain information on the product to be manufactured from the mobile communication device 50. In this way, the fixed communication device 80 does not need to periodically transmit a transmission request signal, thus reducing the load on communication processing.

[0173] Therefore, by using the mobile communication device 50, the load on the fixed communication device 80 for communication processing can be reduced while suppressing the power consumption of the mobile communication device 50. In particular, when the mobile communication device 50 uses an energy storage element as its power source, the amount of usable power is limited, so the effect of suppressing the power consumption of the mobile communication device 50 is significant.

[0174] Furthermore, with the above-described configuration, there is no need to separately install devices in the manufacturing line to detect when the mobile communication device 50 enters a specific area RG1, or when the mobile communication device 50 leaves the specific area RG1. This reduces manufacturing costs.

[0175] According to this embodiment, in the specific region RG1, inspection work on the work plate 10 is performed on the object to be manufactured. The acquisition unit 71 acquires the inspection results of the object to be manufactured as information on the object to be manufactured.

[0176] With the above configuration, the load on the communication processing of the fixed communication device 80 during the inspection work of the manufactured product can be reduced while suppressing the power consumption of the mobile communication device 50.

[0177] According to this embodiment, the transmission request signal includes information about the transmission timing assigned to the mobile communication device 50. The transmission unit 53 transmits information about the product to be manufactured to the fixed communication device 80 at the assigned transmission timing.

[0178] With the above configuration, the timing at which the mobile communication device 50 transmits a transmission request signal can be set so that it does not overlap with the timing at which other mobile communication devices 50 transmit transmission request signals. This makes it possible to avoid signal collisions and reduce power consumption associated with retransmission processing between the mobile communication device 50 and the fixed communication device 80.

[0179] According to this embodiment, the illuminance of the specific area RG1 is set lower than the illuminance of the external area RG2. The determination unit 67 determines whether the illuminance is below a threshold. If the determination unit 67 determines that the illuminance is below a threshold, the mobile communication device 50 determines that it has entered the specific area RG1 from the external area RG2.

[0180] With the above configuration, the mobile communication device 50 can easily determine whether or not it has entered a specific area RG1. Therefore, manufacturing costs can be further reduced.

[0181] According to this embodiment, the wireless communication system 5 comprises a plurality of mobile communication devices 50 attached to a work board 10 that moves along the transport path of the manufacturing line, and a fixed communication device 80 provided outside the manufacturing line. In a specific area RG1 where wireless communication is possible with the fixed communication device 80, inspection work is performed on the manufacturing object placed on the work board 10. The plurality of mobile communication devices 50 acquire inspection results for multiple parts of the manufacturing object.

[0182] Each mobile communication device 50 includes a receiving unit 51, a transmitting unit 53, a storage unit 57, an illuminance detection unit 65, a determination unit 67, a switching unit 69, and an acquisition unit 71. The storage unit 57 stores a threshold TH that distinguishes the illuminance of a specific area RG1 from the illuminance of an external area RG2 other than the specific area RG1. The illuminance detection unit 65 periodically detects the illuminance on the work surface 10. The determination unit 67 compares the illuminance detected by the illuminance detection unit 65 with the threshold TH to determine whether the mobile communication device 50 has entered the specific area RG1 from the external area RG2, and whether it has entered the external area RG2 from the specific area RG1. If the determination unit 67 determines that the mobile communication device 50 has entered the specific area RG1, the switching unit 69 switches the operating mode of the mobile communication device 50 from low power consumption mode to normal mode.

[0183] When the operating mode switches to normal mode, the transmitting unit 53 transmits a first notification signal to the fixed communication device 80 to notify the transition to normal mode. In response to the transmission of the first notification signal, the receiving unit 51 receives a transmission request signal from the fixed communication device 80. In response to the receipt of the transmission request signal, the acquisition unit 71 acquires the inspection results of the corresponding part among multiple parts of the manufactured object. The transmitting unit 53 transmits the inspection results acquired by the acquisition unit 71 to the fixed communication device 80.

[0184] The fixed communication device 80 comprises a receiving unit 81, a transmitting unit 83, and an input / output unit 89. The receiving unit 81 receives a first notification signal from each mobile communication device 50. When the receiving unit 81 receives the first notification signal from all of the multiple mobile communication devices 50, the transmitting unit 83 notifies a transmission request signal. In response to the notification of the transmission request signal, the receiving unit 81 receives the test results from each of the multiple mobile communication devices 50. The input / output unit 89 transmits the received test results to the management device 100.

[0185] Each mobile communication device 50 can wirelessly communicate with a fixed communication device 80 within a predetermined range ER from the boundary BD between a specific area RG1 and the external area RG2, located downstream in the direction of movement of the work board 10, within the external area RG2. When the determination unit 67 determines that a mobile communication device 50 has entered the external area RG2, the transmission unit 53 transmits a second notification signal to the fixed communication device 80 to notify it of a transition to low power consumption mode. When the transmission unit 53 transmits the second notification signal, the switching unit 69 switches the operating mode of the mobile communication device 50 from normal mode to low power consumption mode. In low power consumption mode, the operation of the receiving unit 51, the transmission unit 53, and the acquisition unit 71 is stopped.

[0186] With the configuration described above, the wireless communication system 5 can reduce the load on the fixed communication device 80 for communication processing while suppressing the power consumption of the mobile communication device 50. Furthermore, it can reduce manufacturing costs.

[0187] According to this embodiment, the fixed communication device 80 further includes an assignment unit 97 that assigns a different transmission timing to each of the multiple mobile communication devices 50. In the fixed communication device 80, the transmission unit 83 broadcasts a transmission request signal including the transmission timing assigned to each of the multiple mobile communication devices 50. In each mobile communication device 50, the transmission unit 53 transmits the test result at the transmission timing assigned to its device.

[0188] With the above configuration, the timing at which each mobile communication device 50 transmits a transmission request signal can be set so that it does not overlap with the timing at which other mobile communication devices 50 transmit transmission request signals. This makes it possible to avoid signal collisions and reduce power consumption associated with retransmission processing between the mobile communication device 50 and the fixed communication device 80.

[0189] According to this embodiment, in the fixed communication device 80, if the receiving unit 81 does not receive the first notification signal from all of the multiple mobile communication devices 50 within a first period after first receiving the first notification signal, the transmitting unit 83 broadcasts a first retransmission request signal. In each mobile communication device 50, when the receiving unit 51 receives the first retransmission request signal, the transmitting unit 53 retransmits the first notification signal to the fixed communication device 80.

[0190] With the configuration described above, the fixed communication device 80 can transmit a transmission request signal when it receives a first notification signal from all of the multiple mobile communication devices 50. In this way, the fixed communication device 80 notifies the transmission request signal after recognizing that all of the multiple mobile communication devices 50 have entered the specific area RG1, thereby reducing power consumption associated with signal transmission processing in the fixed communication device 80. It also helps to suppress the transmission of unauthorized manufacturing information signals from the mobile communication devices 50.

[0191] According to this embodiment, in the fixed communication device 80, if the receiving unit 81 does not receive inspection results from all of the multiple mobile communication devices 50 within a second period after transmitting a transmission request signal, the transmitting unit 83 broadcasts a second retransmission request signal. In each mobile communication device 50, when the receiving unit 51 receives the second retransmission request signal, the transmitting unit 53 retransmits the inspection results to the fixed communication device 80.

[0192] In the fixed communication device 80, if the receiving unit 81 has not received inspection results from all of the multiple mobile communication devices 50 at the time the receiving unit 81 has received the second notification signal from all of the multiple mobile communication devices 50, or at the time the third period has elapsed since the first notification signal was received, the input / output unit 89 transmits an abnormality signal to the management device 100.

[0193] With the above configuration, even after all of the multiple mobile communication devices 50 have left the specific area RG1, the fixed communication device 80 can avoid continuing to broadcast the second retransmission request signal. Therefore, the power consumption associated with signal transmission processing in the fixed communication device 80 can be further reduced.

[0194] [Differentiation] In the embodiment described above, there was one inspection step, but the number of inspection steps is not limited to this, and there may be two or more. Figure 19 is an overall schematic diagram of the manufacturing system 1A according to this modified example. As shown in Figure 19, the manufacturing system 1A has inspection steps IP1 to IP3 instead of the inspection step IP in the manufacturing system 1.

[0195] For example, in manufacturing system 1, the five parts attached to the manufactured object are classified as the same type, so only one inspection process is provided. In contrast, in manufacturing system 1A, the five parts attached to the manufactured object are classified as three types, so three inspection processes are provided according to the type of part.

[0196] In the manufacturing line of manufacturing system 1A, inspection steps IP1, IP2, and IP3 are provided along the direction of movement of the work plate 10. Accordingly, in manufacturing system 1A, the specific area where wireless communication is possible between the mobile communication device 50 and the fixed communication device 80 is divided into divided areas RG11 to RG13. Therefore, the manufacturing line of manufacturing system 1A has divided areas RG11 to RG13 and an external area RG2.

[0197] The divided region RG11 is the area where inspection process IP1 is performed. The divided region RG12 is the area where inspection process IP2 is performed. The divided region RG13 is the area where inspection process IP3 is performed. The external region RG2 is the area other than the areas where inspection processes IP1 to IP3 are performed.

[0198] When the mobile communication device 50 enters the divided area RG11, it starts wireless communication with the fixed communication device 80, and when it exits the divided area RG13, it terminates wireless communication with the fixed communication device 80.

[0199] In the manufacturing line, the lighting in divided areas RG11 to RG13 is set to be dimmer than the lighting in the external area RG2 so that the mobile communication device 50 can identify entry into divided area RG11, entry into divided area RG12, entry into divided area RG13, and entry into the external area RG2. With this setting, the illuminances B to D in divided areas RG11 to RG13 are lower than the illuminance A in the external area RG2.

[0200] Furthermore, the lighting in divided area RG11 is brighter than the lighting in divided areas RG12 and RG13, and the lighting in divided area RG12 is brighter than the lighting in divided area RG13. With this setting, the illuminances B to D in divided areas RG11 to RG13 are set to decrease along the direction of movement of the work board 10.

[0201] Figure 20 illustrates the setting of illuminance in manufacturing system 1A. As shown in Figure 20, the illuminance between illuminances A and B is set as threshold TH1, which distinguishes illuminance A in the outer area RG2 from illuminance B in the divided area RG11. The illuminance between illuminances B and C is set as threshold TH2, which distinguishes illuminance B in the divided area RG11 from illuminance C in the divided area RG12. The illuminance between illuminances C and D is set as threshold TH3, which distinguishes illuminance C in the divided area RG12 from illuminance D in the divided area RG13. Threshold TH1 is also referred to as the first threshold. Thresholds TH2 and TH3 are also referred to as the second thresholds.

[0202] Figure 21 is a circuit diagram showing an example of a detection circuit 213A used in manufacturing system 1A. As shown in Figure 21, in detection circuit 213A, a signal output line for outputting an illuminance signal Vin is added to the detection circuit 213 shown in Figure 8 in order to acquire illuminance as an analog value. The mobile communication device 50 performs A / D conversion (analog-to-digital conversion) of the illuminance signal Vin output from detection circuit 213A and uses it for comparison with thresholds TH1 to TH3.

[0203] In this configuration, the mobile communication device 50 performs the following operations. The determination unit 67 compares the illuminance detected by the illuminance detection unit 65 with the threshold TH1 to determine whether the mobile communication device 50 has entered a specific area (divided area RG11) from the external area RG2, and whether it has entered the external area RG2 from the specific area (divided area RG13).

[0204] When the determination unit 67 determines that the mobile communication device 50 has entered a specific area, it compares the illuminance detected by the illuminance detection unit 65 with thresholds TH1 to TH3 to determine whether or not it has entered one of the divided areas RG11 to RG13. If the determination unit 67 determines that it has entered one of the divided areas, the acquisition unit 71, in response to the receipt of the transmission request signal, acquires the results of the inspection work on the manufactured object performed in that divided area as manufacturing information for the manufactured object.

[0205] Figure 22 is a diagram showing an example of the operation flowchart of the mobile communication device 50 in manufacturing system 1A. Figure 22 shows an example of the operation of the mobile communication device 50 from the time it enters a specific area (divided area RG11) until it exits the specific area (divided area RG13).

[0206] As shown in Figure 22, when the mobile communication device 50 detects the illuminance on the work surface 10, it determines whether the detected illuminance is less than or equal to the threshold TH1 (step S101). If the mobile communication device 50 determines that the detected illuminance is not less than or equal to the threshold TH1, it detects the illuminance on the work surface 10 after a predetermined time has elapsed and returns to step S101.

[0207] On the other hand, if the mobile communication device 50 determines that the detected illuminance is below the threshold TH1, it determines that it has entered a specific area (divided area RG11) from the external area RG2 and switches its operating mode from low power consumption mode to normal mode (step S103). When the mobile communication device 50 switches its operating mode to normal mode, it transmits a first notification signal to the fixed communication device 80 to notify it of the transition to normal mode.

[0208] When the mobile communication device 50 transmits a first notification signal to the fixed communication device 80, it transmits manufacturing information of the manufactured object corresponding to the inspection process IP1 (results of the inspection work on the manufactured object) to the fixed communication device 80 (step S105).

[0209] After determining that it has entered the divided area RG11, the mobile communication device 50 detects the illuminance on the work board 10 and determines whether the detected illuminance is less than or equal to the threshold TH2 (step S107). If the mobile communication device 50 determines that the detected illuminance is not less than or equal to the threshold TH2, it detects the illuminance on the work board 10 after a predetermined time has elapsed and returns to step S107.

[0210] On the other hand, if the mobile communication device 50 determines that the detected illuminance is below the threshold TH2, it determines that it has entered the divided area RG12 from the divided area RG11 and transmits manufacturing information of the manufactured object corresponding to the inspection process IP2 (the result of the inspection work on the manufactured object) to the fixed communication device 80 (step S109).

[0211] After determining that it has entered the divided area RG12, the mobile communication device 50 detects the illuminance on the work board 10 and determines whether the detected illuminance is less than or equal to the threshold TH3 (step S111). If the mobile communication device 50 determines that the detected illuminance is not less than or equal to the threshold TH3, it detects the illuminance on the work board 10 after a predetermined time has elapsed and returns to step S111.

[0212] On the other hand, if the mobile communication device 50 determines that the detected illuminance is less than or equal to the threshold TH3, it determines that it has entered the divided area RG13 from the divided area RG12 and transmits manufacturing information of the manufactured object corresponding to the inspection process IP3 (the result of the inspection work on the manufactured object) to the fixed communication device 80 (step S113).

[0213] After determining that it has entered the divided area RG13, the mobile communication device 50 detects the illuminance on the work board 10 and determines whether the detected illuminance exceeds the threshold TH1 (step S115). If the mobile communication device 50 determines that the detected illuminance does not exceed the threshold TH1, it detects the illuminance on the work board 10 after a predetermined time has elapsed and returns to step S115.

[0214] On the other hand, if the mobile communication device 50 determines that the detected illuminance exceeds the threshold TH1, it determines that it has entered the external area RG2 from the divided area RG13 and transmits a second notification signal to the fixed communication device 80 (step S117). After transmitting the second notification signal, the mobile communication device 50 switches its operating mode from normal mode to low power consumption mode (step S119). After switching the operating mode to low power consumption mode, the mobile communication device 50 stops the operation of the receiving unit 51, transmitting unit 53, input / output unit 59, frame generation unit 61, communication processing unit 63, and acquisition unit 71.

[0215] Furthermore, the mobile communication device 50 may perform the following operation each time it detects illuminance: The mobile communication device 50 determines whether the detected illuminance is less than or equal to the threshold TH1. If the mobile communication device 50 determines that the detected illuminance is not less than or equal to the threshold TH1, it determines that it has entered the external area RG2.

[0216] On the other hand, if the mobile communication device 50 determines that the detected illuminance is less than or equal to threshold TH1, it determines whether or not the detected illuminance is less than or equal to threshold TH3. If the mobile communication device 50 determines that the detected illuminance is less than or equal to threshold TH3, it determines that it has entered the divided area RG13 and transmits manufacturing information of the manufactured object (results of the inspection work on the manufactured object) corresponding to the inspection process IP3 to the fixed communication device 80.

[0217] On the other hand, if the mobile communication device 50 determines that the detected illuminance is not below the threshold TH3, it determines whether the detected illuminance is below the threshold TH2. If the mobile communication device 50 determines that the detected illuminance is below the threshold TH2, it determines that it has entered the divided area RG12 and transmits manufacturing information of the manufactured object (results of the inspection work on the manufactured object) corresponding to the inspection process IP2 to the fixed communication device 80.

[0218] On the other hand, if the mobile communication device 50 determines that the detected illuminance is not below the threshold TH2, it determines that it has entered the divided area RG11 and transmits manufacturing information of the manufactured object corresponding to the inspection process IP1 (the result of the inspection work on the manufactured object) to the fixed communication device 80.

[0219] According to this embodiment, the specific area has divided areas RG11 to RG13. In divided areas RG11 to RG13, different inspection operations are performed on the work surface 10. The illuminance of the external area RG2 is set higher than the illuminance of the divided areas RG11 to RG13. The illuminance of the divided areas RG11 to RG13 is set to decrease along the direction of movement of the work surface 10.

[0220] Threshold TH1 distinguishes between the illuminance of the divided region RG11, which is in contact with the outer region RG2 on the upstream side in the direction of movement of the work plate 10, and the illuminance of the outer region RG2. Threshold TH2 distinguishes between the illuminances of adjacent divided regions RG11 and RG12. Threshold TH3 distinguishes between the illuminances of adjacent divided regions RG12 and RG13.

[0221] The determination unit 67 compares the illuminance detected by the illuminance detection unit 65 with the threshold TH1 to determine whether the mobile communication device 50 has entered a specific area (divided area RG11) from the external area RG2, and whether it has entered the external area RG2 from the specific area (divided area RG13).

[0222] When the determination unit 67 determines that the mobile communication device 50 has entered a specific area (divided area RG11), it compares the illuminance detected by the illuminance detection unit 65 with thresholds TH1 to TH3 to determine whether or not it has entered one of the divided areas RG11 to RG13. If the determination unit 67 determines that it has entered one of the divided areas, the acquisition unit 71, in response to the receipt of the transmission request signal, acquires the results of the inspection work on the manufactured object performed in that divided area as manufacturing information for the manufactured object.

[0223] With the above configuration, even if the manufacturing line has multiple inspection processes, the mobile communication device 50 does not maintain a state where it can receive transmission request signals from the fixed communication device 80 in the external region RG2 other than the specific region (divided regions RG11 to RG13). Therefore, by using the mobile communication device 50, it is possible to efficiently transmit product manufacturing information corresponding to each inspection process to the fixed communication device 80 while suppressing the power consumption of the mobile communication device 50.

[0224] [Other variations] In the embodiment described above, the illuminance of the specific region RG1 was set lower than that of the external region RG2, but this is not limited to this. The illuminance of the specific region RG1 may be set higher than that of the external region RG2.

[0225] In this case, the determination unit 67 determines whether the illuminance exceeds a threshold. If the determination unit 67 determines that the illuminance exceeds the threshold, the mobile communication device 50 determines that it has entered the specific area RG1 from the external area RG2. This configuration also allows the mobile communication device 50 to easily determine whether it has entered the specific area RG1. Therefore, manufacturing costs can be further reduced.

[0226] In the embodiment described above, the illuminance of the specific region RG1 was set lower than that of the external region RG2, but the lighting in the specific region RG1 may be turned off.

[0227] In the embodiment described above, the area where the inspection process IP is performed (inspection process area) along the direction of movement of the work plate 10 coincided with a specific area RG1 where wireless communication between the mobile communication device 50 and the fixed communication device 80 takes place, but is not limited to this.

[0228] For example, the illuminance within a predetermined range from the boundary between the inspection process area and other areas outside the inspection process area, located upstream of the movement direction of the work plate 10 in the inspection process area, may be the same as the illuminance of the external area RG2. This setting allows the worker to complete the task of holding the parts attached to the manufacturing object in the holding section 41 of the inspection device 30 within the predetermined range. This ensures that the situation in which the worker has not yet held the parts attached to the manufacturing object in the holding section 41 of the inspection device 30 at the time the mobile communication device 50 transmits a transmission request signal to the inspection device 30 can be reliably avoided.

[0229] In the embodiment described above, the manufacturing information of the manufactured object was the inspection result of the manufactured object, but is not limited to this. For example, the manufacturing information of the manufactured object may be attribute information of the manufactured object.

[0230] In the embodiment described above, the allocation unit 97 allocated time slots to each mobile communication device 50 in the order in which they entered the specific area RG1, but is not limited to this. For example, the allocation unit 97 may allocate time slots to each mobile communication device 50 based on the amount of charge stored in the power supply 20.

[0231] In the embodiment described above, the fixed communication device 80 transmits a transmission request signal when it receives a first notification signal from all of the multiple mobile communication devices 50, but it is not limited to this. For example, the fixed communication device 80 may transmit a transmission request signal after a predetermined time has elapsed from the time it receives the first notification signal. The predetermined period is, for example, the time it takes for one end of the work plate 10 to enter the specific area RG1 in the direction of movement of the work plate 10 until the other end of the work plate 10 enters the specific area RG1.

[0232] This allows the fixed communication device 80 to transmit a transmission request signal even if, for some reason, it is unable to receive the first notification signal from some of the multiple mobile communication devices 50. Therefore, the power consumption of the mobile communication devices 50 associated with the retransmission process of the first notification signal can be reduced.

[0233] Although this embodiment has been described above, this embodiment is not limited to these, and various modifications are possible within the scope of the gist of this embodiment. [Explanation of Symbols]

[0234] 5 Wireless communication systems 10 Work boards 50 Mobile communication devices 51 Receiving unit 53 Transmitter 57 Memory section 65 Illuminance detection unit 67 Judgment section 69 Switching section 71 Acquisition Department 80 Fixed communication equipment 81 Receiving Unit 83 Transmitter 89 Input / output section 97 Allocation Section 100 Management device RG1 Specific area RG2 external area RG11, RG12, RG13 divided area TH, TH1, TH2, TH3 thresholds

Claims

1. A mobile communication device attached to a work platform that moves along a transport path on a manufacturing line, A storage unit that stores a threshold value for distinguishing between the illuminance of a specific area that can be wirelessly communicated with a fixed communication device located outside the manufacturing line and the illuminance of an external area other than the specific area, An illuminance detection unit periodically detects the illuminance on the work surface, A determination unit compares the illuminance detected by the illuminance detection unit with the threshold value to determine whether the mobile communication device has entered the specific area from the external area, and whether it has entered the external area from the specific area. When the determination unit determines that the mobile communication device has entered the specific area, a switching unit switches the operating mode of the mobile communication device from low power consumption mode to normal mode. When the operating mode switches to the normal mode, a first transmitting unit transmits a first notification signal to the fixed communication device to notify the transition to the normal mode. A receiving unit that receives a transmission request signal from the fixed communication device in response to the transmission of the first notification signal, In response to receiving the aforementioned transmission request signal, an acquisition unit acquires information about the manufacturing object placed on the work plate, A second transmission unit transmits the information on the manufacturing target acquired by the acquisition unit to the fixed communication device. Equipped with, The mobile communication device is capable of wireless communication with the fixed communication device within a predetermined range from the boundary between the specific area and the external area, located downstream in the direction of movement of the work plate within the external area. If the determination unit determines that the mobile communication device has entered the external area, the first transmission unit transmits a second notification signal to the fixed communication device to notify it of the transition to the low-power mode. When the first transmitting unit transmits the second notification signal, the switching unit switches the operating mode of the mobile communication device from the normal mode to the low power consumption mode. In the low-power mode, the operation of the first transmitting unit, the second transmitting unit, the receiving unit, and the acquisition unit is stopped in the mobile communication device.

2. In the aforementioned specific area, the inspection work of the object to be manufactured is performed on the work surface. The mobile communication device according to claim 1, wherein the acquisition unit acquires the inspection results of the manufactured object as information of the manufactured object.

3. The aforementioned transmission request signal includes information about the transmission timing assigned to the mobile communication device. The mobile communication device according to claim 1, wherein the second transmitting unit transmits information about the product to be manufactured to the fixed communication device at the assigned transmission timing.

4. The illuminance of the aforementioned specific area is set lower than the illuminance of the aforementioned external area. The determination unit determines whether the illuminance is below the threshold, The mobile communication device according to claim 1, wherein the determination unit determines that the illuminance is below the threshold, and the mobile communication device determines that it has entered the specific area from the external area.

5. The illuminance of the aforementioned specific area is set higher than the illuminance of the aforementioned external area. The determination unit determines whether the illuminance exceeds the threshold, The mobile communication device according to claim 1, wherein the determination unit determines that the illuminance exceeds the threshold, and the mobile communication device determines that it has entered the specific area from the external area.

6. The aforementioned specific region has multiple divided regions, In the aforementioned multiple divided regions, different inspection operations are performed on the work surface on the work plate. The illuminance of the aforementioned external region is set higher than the illuminance of the aforementioned multiple divided regions. The illuminance of the aforementioned multiple divided regions is set to decrease along the direction of movement of the work plate. The threshold comprises a first threshold that distinguishes between the illuminance of a divided region in contact with the external region on the upstream side in the direction of movement of the work plate within the specific region and the illuminance of the external region, and a second threshold that distinguishes between the illuminance of adjacent divided regions. The determination unit compares the illuminance detected by the illuminance detection unit with the first threshold value to determine whether the mobile communication device has entered the specific area from the external area, and whether it has entered the external area from the specific area. When the determination unit determines that the mobile communication device has entered the specific area, it compares the illuminance detected by the illuminance detection unit with the first threshold or the second threshold to determine whether or not the device has entered one of the plurality of divided areas. The mobile communication device according to claim 1, wherein when the determination unit determines that the device has entered one of the divided regions, the acquisition unit, in response to the receipt of the transmission request signal, acquires the results of the inspection work on the manufactured object performed in the one divided region as information on the manufactured object.

7. Multiple mobile communication devices attached to a work platform that moves along the transport path of a manufacturing line, A fixed communication device installed outside the aforementioned manufacturing line, Equipped with, In a specific area where wireless communication is possible with the aforementioned fixed communication device, inspection work is performed on the work plate containing the object to be manufactured. The aforementioned multiple mobile communication devices acquire inspection results for multiple parts of the manufactured object, Each mobile communication device, A storage unit that stores a threshold value for distinguishing between the illuminance of the specified region and the illuminance of an external region other than the specified region, An illuminance detection unit periodically detects the illuminance on the work surface, A determination unit compares the illuminance detected by the illuminance detection unit with the threshold value to determine whether the mobile communication device has entered the specific area from the external area, and whether it has entered the external area from the specific area. When the determination unit determines that the mobile communication device has entered the specific area, a switching unit switches the operating mode of the mobile communication device from low power consumption mode to normal mode. When the operating mode switches to the normal mode, a first transmitting unit transmits a first notification signal to the fixed communication device to notify the transition to the normal mode. A first receiving unit receives a transmission request signal from the fixed communication device in response to the transmission of the first notification signal, In response to receiving the transmission request signal, an acquisition unit acquires the inspection result of a corresponding part among the plurality of parts of the manufactured object. A second transmission unit transmits the inspection results acquired by the acquisition unit to the fixed communication device, Equipped with, The aforementioned fixed communication device is A second receiving unit that receives the first notification signal from each mobile communication device, When the second receiving unit receives the first notification signal from all of the plurality of mobile communication devices, the third transmitting unit broadcasts the transmission request signal, A third receiving unit receives the inspection results from each of the plurality of mobile communication devices in response to the notification of the transmission request signal, A fourth transmission unit that transmits the received inspection results to a management device, Equipped with, Each mobile communication device is capable of wireless communication with the fixed communication device within a predetermined range from the boundary between the specific area and the external area, located downstream in the direction of movement of the work plate within the external area. If the determination unit determines that the mobile communication device has entered the external area, the first transmission unit transmits a second notification signal to the fixed communication device to notify it of the transition to the low-power mode. When the first transmitting unit transmits the second notification signal, the switching unit switches the operating mode of the mobile communication device from the normal mode to the low power consumption mode. A wireless communication system in which, in the low power consumption mode, the operation of the first transmitting unit, the second transmitting unit, the first receiving unit, and the acquisition unit is stopped.

8. The fixed communication device further comprises an assignment unit that assigns different transmission timings to each of the plurality of mobile communication devices. In the fixed communication device, the third transmitting unit broadcasts the transmission request signal, including the transmission timing assigned to each of the plurality of mobile communication devices, The wireless communication system according to claim 7, wherein in each mobile communication device, the second transmitting unit transmits the inspection result at the transmission timing assigned to the device.

9. In the fixed communication device, if the third transmitting unit does not receive the first notification signal from all of the plurality of mobile communication devices within a first period after the second receiving unit first receives the first notification signal, it shall broadcast a first retransmission request signal. The wireless communication system according to claim 7, wherein in each mobile communication device, the first transmitting unit retransmits the first notification signal to the fixed communication device when the first receiving unit receives the first retransmission request signal.

10. In the fixed communication device, if the third transmitting unit does not receive the test results from all of the plurality of mobile communication devices within a second period after the third receiving unit transmits the transmission request signal, the third transmitting unit shall broadcast a second retransmission request signal. In each mobile communication device, when the first receiving unit receives the second retransmission request signal, the second transmitting unit retransmits the inspection result to the fixed communication device. The wireless communication system according to claim 7, wherein in the fixed communication device, if the third receiving unit has not received the inspection results from all of the multiple mobile communication devices at the time the second receiving unit has received the second notification signal from all of the multiple mobile communication devices, or at the time a third period has elapsed since the first reception of the first notification signal, the fourth transmitting unit transmits an abnormality signal to the management device.

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