Wireless communication system, picking system, first wireless communication device, and second wireless communication device

Abstract

To reduce power consumption without sacrificing the responsiveness of a wireless communication device receiving intermittently.SOLUTION: A first wireless communication device 10 transmits a first signal instructing a second wireless communication device 20 to change a time interval of intermittent drive and a second signal instructing the second wireless communication device 20 to perform a function. When the first signal is received, a reception mode switching unit 25 of the second wireless communication device 20 switches a reception mode of the second wireless communication device 20 between a first reception mode in which the first signal is received by intermittent drive at first time intervals and a second reception mode in which the second signal is received by intermittent drive at second time intervals shorter than the first time intervals.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a wireless communication system, a picking system, a first wireless communication device, and a second wireless communication device. [Background technology]

[0002] Patent Document 1 discloses a wireless communication device that performs intermittent reception at time intervals instructed by a base station. The wireless communication device described in Patent Document 1 reduces power consumption by putting the wireless unit into a sleep state when not receiving. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-27203 Summary of the Invention [Problem to be solved by the invention]

[0004] In order for a wireless communication device that performs intermittent reception to ensure high-speed response, it is necessary to frequently receive signals transmitted by a base station, i.e., to shorten the time interval of the intermittent reception. On the other hand, the shorter the time interval of the intermittent reception, the greater the power consumption of the wireless communication device. However, Patent Document 1 does not anticipate or describe the above problem.

[0005] An object of the present invention is to reduce power consumption without sacrificing the responsiveness of a wireless communication device that performs intermittent reception. [Means for solving the problem]

[0006] According to a first aspect of the present invention, a wireless communication system includes a first wireless communication device and two or more second wireless communication devices. The first wireless communication device transmits a first signal for instructing the second wireless communication device to change a time interval of intermittent drive, and a second signal for instructing the second wireless communication device to execute a function. The second wireless communication device receives the signal transmitted by the first wireless communication device by intermittently driving at a predetermined time interval. The second wireless communication device also includes a reception mode switching unit that switches a reception mode of the second wireless communication device between a first reception mode in which the first signal is intermittently driven at a first time interval to receive the first signal, and a second reception mode in which the second signal is intermittently driven at a second time interval shorter than the first time interval to receive the second signal.

[0007] According to a second aspect of the present invention, a picking system includes an intermittent operation management unit that manages a timing at which the first wireless communication device transmits the second signal to the second wireless communication device. The second wireless communication device is provided corresponding to an object to be picked and includes a notification unit that notifies a position of the object to be picked. The intermittent operation management unit predicts a timing at which the first wireless communication device will transmit the second signal, which commands the second wireless communication device to notify the position of the object to be picked, based on picking schedule information. Furthermore, the intermittent operation management unit causes the first wireless communication device to transmit the first signal to the second wireless communication device at a timing earlier than the predicted timing.

[0008] According to a third aspect of the present invention, a first wireless communication device transmits a signal to one or more second wireless communication devices that receive signals by intermittently driving at a predetermined time interval, and communicates with the second wireless communication devices. The first wireless communication device transmits a first signal to instruct the second wireless communication device to change the time interval of the intermittent driving, and a second signal to instruct the second wireless communication device to execute a function.

[0009] According to a fourth aspect of the present invention, a second wireless communication device receives a first signal, which is transmitted by a first wireless communication device and commands a change in the time interval of the intermittent drive or a second signal, which commands the execution of a function, by intermittently driving at a predetermined time interval, and communicates with the first wireless communication device. When the second wireless communication device receives the first signal, the second wireless communication device switches a reception mode of the second wireless communication device between a first reception mode in which the first signal transmitted by the first wireless communication device is received by intermittently driving at a first time interval, and a second reception mode in which the second signal transmitted by the first wireless communication device is received by intermittently driving at a second time interval shorter than the first time interval. Effect of the Invention

[0010] According to the present invention, it is possible to reduce power consumption without sacrificing the responsiveness of a wireless communication device that performs intermittent reception. [Brief description of the drawings]

[0011] [Figure 1] 1 is a block diagram showing a configuration of a wireless communication system according to a first embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a basic operation of the wireless communication system according to the first embodiment. [Diagram 3] 4A to 4C are diagrams illustrating a first reception mode and a second reception mode in the first embodiment. [Figure 4] FIG. 1 is a diagram illustrating an overview of a picking system according to a first embodiment. [Diagram 5] FIG. 4 is a diagram showing an example of a picking schedule in the first embodiment. [Figure 6] 4 is a flowchart showing an operation example of the picking system according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and description thereof will not be repeated.

[0013] <Embodiment 1> A wireless communication system 1 according to a first embodiment and a picking system including the wireless communication system 1 will be described with reference to FIGS.

[0014] 1 is a block diagram showing a configuration of a wireless communication system 1 according to a first embodiment. The wireless communication system 1 includes a first wireless communication device 10 and one or more second wireless communication devices 20. Each of the one or more second wireless communication devices 20 has the same internal configuration. The wireless communication system 1 may include an intermittent operation management unit 30 in addition to the first wireless communication device 10 and the second wireless communication device 20. In the first embodiment, a configuration example in which the wireless communication system 1 includes the first wireless communication device 10, the second wireless communication device 20, and the intermittent operation management unit 30 will be described.

[0015] The first wireless communication device 10 includes a first wireless communication unit 11, a first antenna 12, a first control unit 13, a first storage unit 14, and a communication unit 15. The second wireless communication device 20 includes a second wireless communication unit 21, a second antenna 22, a second control unit 23, a second storage unit 24, a reception mode switching unit 25, and a notification unit 26. The intermittent operation management unit 30 includes a third storage unit 31 and a communication unit 32.

[0016] The first antenna 12 transmits and receives radio signals to and from the second antenna 22. The first wireless communication unit 11 performs wireless communication with the second wireless communication device 20 via the first antenna 12.

[0017] The first control unit 13 controls the operation of each unit of the first wireless communication device 10. The first control unit 13 causes the first wireless communication unit 11 to transmit a wireless signal at a fixed cycle (here, 200 ms cycle). Hereinafter, the wireless signal from the first wireless communication device 10 is also referred to as a "beacon". The beacon may include at least one of a first signal and a second signal. The first control unit 13 controls the first wireless communication unit 11 to transmit the generated beacon intermittently at a second time interval. The first control unit 13 also causes the first wireless communication unit 11 to perform a receiving operation during a time other than the beacon transmission. The first control unit 13 also stores, in the first storage unit 14, timing prediction information received by the communication unit 15 from the intermittent operation management unit 30. The timing prediction information is generated and managed by the intermittent operation management unit 30, as described later. The first control unit 13 controls the timing of transmitting the first signal and the second signal to the second wireless communication device 20 based on the timing prediction information stored in the first storage unit 14.

[0018] The first control unit 13 is not limited to a configuration in which the timing prediction information is acquired by communication from the intermittent operation management unit 30. The first control unit 13 may acquire the part pick-up order for each worker (corresponding to the picking schedules 61 and 62 shown in FIG. 5 ) from the intermittent operation management unit 30 and predict the timing of transmitting the first signal or the second signal to the second wireless communication device 20.

[0019] The first signal is a signal that commands the second wireless communication device 20 to change the time interval of the intermittent drive. The first signal is a signal that commands the second wireless communication device 20 to change the time interval of the intermittent drive from the first time interval to the second time interval, or from the second time interval to the first time interval. The length of the first time interval is, for example, 2000 ms. The length of the second time interval is shorter than the first time interval, for example, 200 ms. Furthermore, the first signal may include time interval designation information that designates the length of the first time interval or the length of the second time interval. The first signal may include device designation information that designates the second wireless communication device 20 that commands the second wireless communication device 20 to change the time interval of the intermittent drive.

[0020] The second signal is a signal that commands the second wireless communication device 20 to execute a function. The function of the second wireless communication device 20 is, for example, a notification function executed by the notification unit .

[0021] The first storage unit 14 stores information indicating the length of the first time interval and information indicating the length of the second time interval.

[0022] The communication unit 15 is connected via a wire to the communication unit 32 of the intermittent operation management unit 30 to transmit and receive signals. Note that, in the first embodiment, the communication unit 15 and the communication unit 32 are connected via a wire, but the communication unit 15 and the communication unit 32 may be connected wirelessly.

[0023] The second antenna 22 transmits and receives radio signals to and from the first antenna 12. The second wireless communication unit 21 performs wireless communication with the first wireless communication device 10 via the second antenna 22.

[0024] The second control unit 23 has a sleep function using a timer (not shown) and controls the operation of each unit of the second wireless communication device 20 while performing intermittent operation according to the reception mode. For example, when the beacon includes the first signal, the second control unit 23 instructs the reception mode switching unit 25 to switch the reception mode. When the first signal addressed to the device includes time interval designation information that designates the length of the first time interval or the second time interval, the second control unit 23 stores the time interval designation information that designates the length of the first time interval or the second time interval in the second storage unit 24. When the beacon includes the second signal, the second control unit 23 operates the notification unit 26 according to the second signal.

[0025] The second storage unit 24 stores information indicating the length of the first time interval and information indicating the length of the second time interval.

[0026] The reception mode switching unit 25 switches the reception mode of the second wireless communication device 20 between a first reception mode and a second reception mode in accordance with an instruction from the second control unit 23. The first reception mode is a mode in which the second wireless communication unit 21 and the second control unit 23 are intermittently driven at a first time interval to receive a beacon. The second reception mode is a mode in which the second wireless communication unit 21 and the second control unit 23 are intermittently driven at a second time interval to receive a beacon. When switching from the second reception mode to the first reception mode, the reception mode switching unit 25 reads information indicating the length of the first time interval from the second storage unit 24, intermittently drives the second wireless communication unit 21 and the second control unit 23 at each first time interval, and puts the second wireless communication unit 21 and the second control unit 23 into sleep mode during the rest of the time. When switching from the first reception mode to the second reception mode, the reception mode switching unit 25 reads information indicating the length of the second time interval from the second memory unit 24, and intermittently drives the second wireless communication unit 21 and the second control unit 23 for each second time interval, and puts the second wireless communication unit 21 and the second control unit 23 to sleep during the rest of the time.

[0027] The notification unit 26 is an example of a function included in the second wireless communication device 20. For example, the notification unit 26 is a display device such as an LED (Light Emitting Diode) or an LCD (Liquid Crystal Display), and turns on and off and displays character strings or the like according to an instruction from the second control unit 23. For example, the notification unit 26 is a speaker, and emits a sound according to an instruction from the second control unit 23. In the illustrated example, the second wireless communication device 20 is configured to have the notification unit 26 built in, but the notification unit 26 may be configured to be externally attached to the second wireless communication device 20. Note that the notification unit 26 may be configured to autonomously maintain blinking or display after receiving an instruction until receiving the next instruction. In this configuration, the notification unit 26 can maintain blinking or display during a period when the second control unit 23, which performs intermittent operation, is in a sleep state.

[0028] The intermittent operation management unit 30 predicts the timing when the first wireless communication device 10 transmits a second signal to the second wireless communication device 20. The timing when the second signal is transmitted is the timing when the second wireless communication device 20 is caused to execute a function. The intermittent operation management unit 30 also predicts the timing when the first wireless communication device 10 transmits a first signal to the second wireless communication device 20. The timing when the first signal is transmitted is the timing when the reception mode of the second wireless communication device 20 is switched. The intermittent operation management unit 30 transmits timing prediction information indicating the predicted timing to the first wireless communication device 10 via the communication unit 32.

[0029] The third storage unit 31 stores a management table for managing the reception mode for each second wireless communication device 20. The management table will be described in detail later.

[0030] The communication unit 32 is connected to the communication unit 15 of the first wireless communication device 10 via a wired connection to transmit and receive signals.

[0031] Here, an example of the hardware configuration of the first wireless communication device 10, the second wireless communication device 20, and the intermittent operation management unit 30 will be described. The first control unit 13 has, for example, a processor such as a CPU (Central Processing Unit) and a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory). For example, the first control unit 13 executes various processes defined in the computer program by the processor executing a computer program previously stored in the memory. Each of the second control unit 23, the reception mode switching unit 25, and the intermittent operation management unit 30 also has a processor and a memory like the first control unit 13, and executes various processes defined in the computer program by the processor executing a computer program previously stored in the memory. Note that the reception mode switching unit 25 may be realized by a dedicated circuit.

[0032] The first storage unit 14 is realized by a non-volatile memory such as an EEPROM (registered trademark) (Electrically Erasable Programmable ROM) or a FRAM (registered trademark) (Ferroelectric RAM). The second storage unit 24 and the third storage unit 31 are also realized by a non-volatile memory, similar to the first storage unit 14.

[0033] The first wireless communication unit 11 is realized by a dedicated circuit including the first antenna 12. The second wireless communication unit 21 is also realized by a circuit similar to that of the first wireless communication unit 11. The communication unit 15 and the communication unit 32 are interfaces that perform communication.

[0034] 2 is a diagram for explaining a basic operation of the wireless communication system 1 according to the first embodiment. Each of the one or more second wireless communication devices 20 is associated with one first wireless communication device 10, and communicates only with the associated first wireless communication device 10. That is, the connection form between the first wireless communication device 10 and the second wireless communication device 20 is a star topology. The first wireless communication device 10 is a wireless communication device such as a beacon transmitter that transmits beacons. The second wireless communication device 20 is a wireless communication device such as a beacon receiver that receives beacons.

[0035] The first wireless communication device 10 transmits a beacon at a second time interval (for example, 200 ms) to all associated second wireless communication devices 20. The first wireless communication device 10 performs a receiving operation during times other than when it is transmitting a beacon.

[0036] Each second wireless communication device 20 is activated at each second time interval and receives a beacon transmitted by the first wireless communication device 10. More specifically, the reception mode switching unit 25 counts the length of the second time interval using a timer (not shown), and activates the second wireless communication unit 21 and the second control unit 23 at timing T1 immediately before the second time interval. At timing T2 after activation, the second wireless communication unit 21 starts a receiving operation.

[0037] When the beacon received by the second wireless communication unit 21 contains a signal addressed to the device itself, the second control unit 23 controls each unit according to the signal, and after the completion of reception at timing T3, the second control unit 23 controls the second wireless communication unit 21 to transmit an acknowledgement (Ack) indicating that control has been performed according to the signal addressed to the device itself to the first wireless communication device 10. At timing T4, the reception mode switching unit 25 puts each unit of the second wireless communication device 20 into a sleep state, sets a timer (not shown) until the next timing T1, and also goes into sleep mode itself.

[0038] If the beacon received by the second wireless communication unit 21 does not include a signal addressed to the device itself, at timing T4, the reception mode switching unit 25 puts each unit of the second wireless communication device 20 into a sleep state, sets a timer (not shown) until the next timing T1, and also goes into sleep mode itself.

[0039] In order to improve the responsiveness of the second wireless communication device 20, it is necessary to shorten the time interval for intermittently driving the second wireless communication device 20, that is, to increase the reception frequency of the second wireless communication device 20. On the other hand, since the power consumption during reception in the second wireless communication device 20 is much larger than the power consumption during sleep, reducing the reception frequency leads to power saving. In particular, when the second wireless communication device 20 is configured to operate on a built-in battery, power saving becomes more important. Therefore, in the first embodiment, power consumption is reduced by increasing the reception frequency in situations where high-speed responsiveness is required and decreasing the reception frequency in situations where high-speed responsiveness is not required.

[0040] 3 is a diagram for explaining the first reception mode and the second reception mode in the first embodiment. The first wireless communication device 10 transmits a beacon at every second time interval (for example, 200 ms). The second wireless communication device 20 switches the reception mode to the second reception mode when high-speed response is required, and receives every beacon from the first wireless communication device 10 by intermittently driving at the second time interval. On the other hand, the second wireless communication device 20 switches the reception mode to the first reception mode when high-speed response is not required, and does not receive every beacon from the first wireless communication device 10, but receives it at a thinned interval (for example, 2000 ms) such as once in 10 times, and sleeps at other times. The thinned interval such as once in 10 times corresponds to the first time interval.

[0041] Next, an example of the operation of the wireless communication system 1 when applied to a picking system will be described. FIG. 4 is a diagram for explaining an outline of the picking system according to the first embodiment. The picking system is used in a logistics warehouse, a factory, or the like. A shelf 52 is installed in the logistics warehouse or the like. A plurality of parts boxes are stored on the shelf 52. A plurality of parts of one type are stored in one parts box. The parts are objects to be picked. In addition, a first wireless communication device 10 is installed on a pillar, a ceiling, or the like of the logistics warehouse or the like. An intermittent operation management unit 30 is connected to the first wireless communication device 10 by wire.

[0042] The shelf 52 is provided with the same number of second wireless communication devices 20 as the number of parts boxes. In the illustrated example, six second wireless communication devices 20-1 to 20-6, the same number as the six parts boxes, are provided above each of the parts boxes. In the following, the second wireless communication devices 20 for each installation position will be described as "second wireless communication devices 20-1 to 20-6" when it is necessary to distinguish between them, and will be described as "second wireless communication devices 20" when it is not necessary to distinguish between them. A lamp is provided on the second wireless communication device 20 at a position where it is visible to the worker 50. In the illustrated example, the lamp is represented by a white circle (◯). The lamp corresponds to the notification unit 26 shown in FIG. 1.

[0043] An example of how the picking system supports picking work will be described below. The detailed operation of each device will be described later.

[0044] The worker 50 takes out parts from each parts box in a predetermined order and places them in the cart 51. When the part to be picked next by the worker 50 is stored in the parts box below the second wireless communication device 20-5, a lamp of the second wireless communication device 20-5 turns on. Using the lit lamp as a guide, the worker 50 takes out the part from the parts box below the second wireless communication device 20-5 and places it in the cart 51.

[0045] A sensor (not shown) provided in the parts box below the second wireless communication device 20-5 detects that a part has been removed from the parts box. Any type of sensor (not shown) may be used to detect part removal. When the sensor (not shown) detects that a part has been removed from the parts box, it outputs a detection signal to the intermittent operation management unit 30. When the worker 50 has finished removing the parts from the parts box, the lamp of the second wireless communication device 20-5 goes out. Note that the method of detecting part removal is not limited to the method using the above-mentioned sensor (not shown). For example, a method in which the worker 50 presses a button after removing a part may also be used.

[0046] In the picking system, the second signal for instructing the lamp to blink is transmitted from the first wireless communication device so that the second wireless communication devices 20 are lit in the order in which the parts are to be picked according to the order of picking. That is, as soon as a part is picked, a second signal for turning off the lamp is transmitted to the corresponding second wireless communication device 20-5, and a second signal for turning on the lamp is transmitted to the second wireless communication device 20-1 corresponding to the next part to be picked. The picking system repeats this process, enabling the worker 50 to pick parts one after the other reliably and quickly.

[0047] On the other hand, the first signal for instructing to switch the reception mode is transmitted in advance to the second wireless communication device 20-5 so that the period of the intermittent operation of the second wireless communication device 20-5 is equal to or shorter than a predetermined length (i.e., the second time interval) when the second signal is transmitted. In this manner, since the period of the intermittent operation of the second wireless communication device 20-5 is equal to or shorter than a predetermined length when the second signal is transmitted, it is possible to maintain a high reaction speed from when the worker 50 takes out the part corresponding to the second wireless communication device 20-5 until the lamp of the second wireless communication device 20-1 corresponding to the next part lights up, while minimizing power consumption.

[0048] The intermittent operation management unit 30 manages the order of parts to be picked and the current intermittent operation status of each second wireless communication device 20, and thereby controls the transmission of a first signal from the first wireless communication device 10 to the second wireless communication device at the appropriate timing as described above.

[0049] For example, the intermittent operation management unit 30 instructs the first wireless communication device 10 to transmit a first signal to the second wireless communication device 20 that transmits the second signal after 10 seconds, to set the period of the intermittent operation to a predetermined length or less. Also, the intermittent operation management unit 30 instructs the first wireless communication device 10 to transmit a first signal to the second wireless communication device 20 that lengthens the period of the intermittent operation (i.e., sets it to the first time interval) after the first wireless communication device 10 transmits the second signal. Note that, when transmitting the next second signal to the same second wireless communication device 20 immediately after transmitting the second signal, the intermittent operation management unit 30 controls the first wireless communication device 10 not to immediately transmit the first signal that lengthens the period of the intermittent operation.

[0050] In addition, when there are multiple workers 50 and the order of parts to be picked is determined for each worker 50, the intermittent operation management unit 30 may determine the timing of sending the first signal and the second signal depending on the progress of each worker 50.

[0051] 4 shows one first wireless communication device 10 associated with multiple second wireless communication devices 20-1 to 20-6, but multiple first wireless communication devices 10 may be installed in an actual logistics warehouse or the like. In this case, the first wireless communication device 10-1 controls the second wireless communication devices 20-1 to 20-6, and the first wireless communication device 10-2 controls the second wireless communication devices 20-7 to 20-12 (not shown). The intermittent operation management unit 30 controls the multiple first wireless communication devices 10-1, 10-2 to switch the reception modes of the multiple second wireless communication devices 20-1 to 20-12 (not shown).

[0052] The switching between the first and second reception modes of the second wireless communication device 20 in the picking system is managed by the intermittent operation management unit 30. Specific methods include the following (1) to (4). Note that two or more of the methods (1) to (4) may be combined. (1) Switching based on picking schedule (2) Switching based on the brightness of lighting in logistics warehouses, etc. (3) Switching Based on the Presence or Absence of a Function Execution Command to the Second Wireless Communication Device 20 (4) Switching based on the current time

[0053] (1) Switching based on picking schedule 5 is a diagram showing an example of a picking schedule in embodiment 1. Numbers such as "20-1," "20-4," and "20-3" in the picking schedules 61 and 62 correspond to the second wireless communication devices 20, such as the second wireless communication device 20-1, the second wireless communication device 20-4, and the second wireless communication device 20-3 shown in FIG.

[0054] The picking schedule 61 indicates that first, a part stored in the parts box corresponding to the second wireless communication device 20-1 is picked, second, a part stored in the parts box corresponding to the second wireless communication device 20-4 is picked, and third, a part stored in the parts box corresponding to the second wireless communication device 20-3 is picked. The same applies to the fourth and subsequent parts.

[0055] When the timing for turning on and off the alarm unit 26 approaches, the intermittent operation management unit 30 causes the first wireless communication device 10 associated with the target second wireless communication device 20 to transmit a first signal to the target second wireless communication device 20. The reception mode of the target second wireless communication device 20 is switched to the second reception mode to increase the reception frequency and improve the responsiveness of the second wireless communication device 20. In the example of the picking schedule 61, it is time to turn on the alarm unit 26 of the second wireless communication device 20-1 corresponding to the next part to be picked, and the timing for turning on each of the alarm units 26 of the second wireless communication devices 20-4 and 20-3 is approaching. The timing for turning on each of the alarm units 26 of the second wireless communication devices 20-2, 20-6, and 20-5 is still ahead. Therefore, the intermittent operation management unit 30 controls the first wireless communication device 10 to switch the reception mode to the second reception mode for the three second wireless communication devices 20-1, 20-4, 20-3 corresponding to the first three parts including the next part to be taken out of the six parts to be taken from now. The intermittent operation management unit 30 controls the first wireless communication device 10 to switch the reception mode to the first reception mode for the three second wireless communication devices 20-2, 20-6, 20-5 corresponding to the fourth, fifth, and sixth three parts to be taken out of the parts to be taken from now.

[0056] The picking schedule 62 is a schedule in a state where the worker 50 has finished picking up the parts stored in the parts box corresponding to the second wireless communication device 20-1. In the picking schedule 62, the next part to be picked up by the worker 50 is the part stored in the parts box corresponding to the second wireless communication device 20-4. In the example of the picking schedule 62, the intermittent operation management unit 30 turns off the notification unit 26 of the second wireless communication device 20-1 corresponding to the part that has been picked up. In addition, the intermittent operation management unit 30 turns on the notification unit 26 of the second wireless communication device 20-4 corresponding to the next part to be picked. Therefore, the intermittent operation management unit 30 controls the first wireless communication device 10 to switch the reception mode to the second reception mode for the three second wireless communication devices 20-4, 20-3, and 20-2 corresponding to the first three parts including the next part to be picked out of the five parts to be picked out. In addition, the intermittent operation management unit 30 controls the first wireless communication device 10 to switch the reception mode to the first reception mode for a total of three second wireless communication devices 20-1, 20-6, 20-5 corresponding to the parts that have been removed and the two parts that are the fourth and fifth to be removed from among the parts to be removed.

[0057] The third storage unit 31 of the intermittent operation management unit 30 stores a management table for managing the reception mode for each second wireless communication device 20. The management table includes information indicating a picking order, such as a picking schedule 61 and a picking schedule 62, and information indicating the reception mode for each second wireless communication device 20. The intermittent operation management unit 30 updates the reception mode for each second wireless communication device 20 in the management table according to the progress of the picking work. In addition, the first control unit 13 generates a beacon based on an instruction from the intermittent operation management unit 30.

[0058] 6 is a flowchart showing an operation example of the picking system according to the first embodiment. Here, it is assumed that the notification unit 26 of the second wireless communication device 20-1 is turned on based on the picking schedule 61. When the worker 50 takes out a part from the parts box corresponding to the second wireless communication device 20-1, a sensor (not shown) detects that the part has been taken out of the parts box and outputs a detection signal.

[0059] When intermittent operation management unit 30 receives the detection signal, it transmits information indicating that removal of the part corresponding to second wireless communication device 20-1 has been completed and timing prediction information indicating that it is the timing to transmit a second signal to second wireless communication device 20-4 corresponding to the next part to be removed to first wireless communication device 10 via communication unit 32. First control unit 13 receives the information indicating that removal of the part corresponding to second wireless communication device 20-1 has been completed and the timing prediction information indicating that it is the timing to transmit a second signal to second wireless communication device 20-4 corresponding to the next part to be removed from intermittent operation management unit 30 via communication unit 15 (step S1; Yes).

[0060] In step S2, the intermittent operation management unit 30 updates the management table stored in the third storage unit 31 from the picking schedule 61 to the picking schedule 62.

[0061] When the information indicating that the part removal is completed is not received from the intermittent operation management unit 30 (step S1; No), the process of the first control unit 13 proceeds to step S3.

[0062] In step S3, the intermittent operation management unit 30 refers to the management table and determines whether or not there is a second wireless communication device 20 that is to be switched to the second reception mode. Because the management table is in the state shown in the picking schedule 62, the intermittent operation management unit 30 determines that the reception mode of the second wireless communication devices 20-4, 20-3, and 20-2 is to be switched to the second reception mode, and notifies the first wireless communication device 10 of the determination result (step S3; Yes).

[0063] In step S4, in accordance with the notification from intermittent operation management section 30, first control section 13 adds a first signal for intermittently driving second wireless communication devices 20-4, 20-3, and 20-2 at second time intervals to the beacon.

[0064] If there is no second wireless communication device 20 to be switched to the second reception mode (step S3; No), the process of the intermittent operation management unit 30 proceeds to step S5. If there is no second wireless communication device 20 to be switched to the second reception mode, for example, part removal has not been completed and the management table has not been updated in step S2.

[0065] In step S5, the intermittent operation management unit 30 refers to the management table and determines whether or not there is a second wireless communication device 20 that is to be switched to the first reception mode. Because the management table is in the state shown in the picking schedule 62, the intermittent operation management unit 30 determines that the reception mode of the second wireless communication devices 20-1, 20-6, and 20-5 is to be switched to the first reception mode, and notifies the first wireless communication device 10 of the determination result (step S5; Yes).

[0066] In step S6, in accordance with the notification from intermittent operation management section 30, first control section 13 adds a first signal for intermittently driving second wireless communication devices 20-1, 20-6, and 20-5 at first time intervals to the beacon.

[0067] If there is no second wireless communication device 20 to be switched to the first reception mode (step S5; No), the process of the intermittent operation management unit 30 proceeds to step S7. If there is no second wireless communication device 20 to be switched to the first reception mode, for example, this is the case where the part removal is not completed and the management table is not updated in step S2.

[0068] In step S7, the intermittent operation management unit 30 refers to the management table and determines whether there is a second wireless communication device 20 that turns on or off the notification unit 26. Because the management table is in the state shown in the picking schedule 62, the intermittent operation management unit 30 determines to switch each notification unit 26 of the second wireless communication devices 20-1, 20-4 to on or off, and notifies the first wireless communication device 10 of the determination result (step S7; Yes).

[0069] In step S8, the first control unit 13, in accordance with the notification from the intermittent operation management unit 30, adds to the beacon a second signal for switching the alarm unit 26 of the second wireless communication device 20-4 from off to on and a second signal for switching the alarm unit 26 of the second wireless communication device 20-1 from on to off.

[0070] If there is no second wireless communication device 20 that switches the notification unit 26 on or off (step S7; No), the process of the intermittent operation management unit 30 proceeds to step S9. A case where there is no second wireless communication device 20 that switches the notification unit 26 on or off is, for example, a case where the part removal is not completed and the management table is not updated in step S2.

[0071] In step S9, the first control unit 13 determines whether or not a second time interval (e.g., 200 ms) has elapsed since the previous beacon transmission. If the second time interval has elapsed since the previous beacon transmission (step S9; Yes), the process of the first control unit 13 proceeds to step S10. If the second time interval has not elapsed since the previous beacon transmission (step S9; No), the process of the first control unit 13 returns to step S1.

[0072] In step S10, first control unit 13 transmits a beacon to each of second wireless communication devices 20-1 to 20-6 via first wireless communication unit 11. After transmitting the beacon, first control unit 13 switches first wireless communication unit 11 to a receiving state.

[0073] Each of the second wireless communication devices 20-1 to 20-6 operates according to the first signal or the second signal addressed to the device itself that is included in the received beacon. Also, each of the second wireless communication devices 20-1 to 20-6 transmits an acknowledgement (Ack) to the first wireless communication device 10.

[0074] In step S11, first wireless communication unit 11 receives the acknowledgement (Ack) transmitted by second wireless communication devices 20-1 to 20-6. After first wireless communication unit 11 receives the acknowledgement (Ack), the process of first control unit 13 returns to step S1.

[0075] (2) Switching based on the brightness of lighting in logistics warehouses, etc. As a premise, when the lights of a logistics warehouse or the like are on, a high-speed response is required, and when the lights are off, a high-speed response is not required. An illuminance sensor or the like detects the brightness of the lights of the logistics warehouse or the like, and outputs a detection signal to the first wireless communication device 10.

[0076] When it is estimated based on the detection signal that the lighting in the logistics warehouse or the like is on, the first control unit 13 adds a first signal, which is a command to change the time interval of intermittent drive to a second time interval, to the beacon. The first wireless communication unit 11 transmits a beacon including the first signal generated by the first control unit 13 to each second wireless communication device 20. The reception mode switching unit 25 of each second wireless communication device 20 switches the reception mode to a second mode in which the device receives by intermittently driving at a second time interval, in accordance with the first signal.

[0077] When it is estimated based on the detection signal that the lighting of the logistics warehouse or the like is turned off, the first control unit 13 adds a first signal, which is a command to change the time interval of intermittent drive to a first time interval, to the beacon. The first wireless communication unit 11 transmits a beacon including the first signal generated by the first control unit 13 to each second wireless communication device 20. The reception mode switching unit 25 of each second wireless communication device 20 switches the reception mode to a first mode in which intermittent drive is performed at a first time interval to receive, in accordance with the first signal. Note that in this case, since all second wireless communication devices 20 are the target, the first wireless communication device 10 may notify all of them of the switch to the first mode by preparing a broadcast address or a separate predetermined signal, for example.

[0078] (3) Switching Based on the Presence or Absence of a Function Execution Command to the Second Wireless Communication Device 20 As a premise, the second wireless communication device 20, which receives frequent function execution commands, requires high-speed response, whereas the second wireless communication device 20, which receives infrequent function execution commands, does not require high-speed response.

[0079] The first control unit 13 manages the time when a second signal commanding execution of a function is transmitted for each second wireless communication device 20. When generating a beacon, the first control unit 13 assigns a first signal, which is a command to change the time interval of intermittent drive to the second time interval, to a second wireless communication device 20 that has a history of transmitting a next second signal within a predetermined time from the previous transmission of a second signal. Also, when generating a beacon, the first control unit 13 assigns a first signal, which is a command to change the time interval of intermittent drive to the first time interval, to a second wireless communication device 20 that has not transmitted a second signal for a predetermined continuous time.

[0080] (4) Switching based on the current time As a premise, when the current time is within the picking operation time, high-speed response is required, and when the current time is outside the picking operation time, high-speed response is not required.

[0081] The first control unit 13 refers to the picking operation time stored in advance in the first storage unit 14, and when the current time is within the picking operation time, adds a first signal to the beacon, which is a command to change the time interval of the intermittent drive to the second time interval. On the other hand, when the current time is outside the picking operation time, the first control unit 13 adds a first signal to the beacon, which is a command to change the time interval of the intermittent drive to the first time interval.

[0082] In the above examples (2) to (4), the first control unit 13 manages the switching of the reception mode of the second wireless communication device 20, but is not limited to this configuration. As in the above example (1), in the above examples (2) to (4), the intermittent operation management unit 30 may manage the switching of the reception mode of the second wireless communication device 20 and control the first wireless communication device 10.

[0083] The first embodiment has been described above with reference to Fig. 1 to Fig. 6. According to the first embodiment, the power consumption of the second wireless communication device 20 can be reduced without sacrificing the responsiveness of the second wireless communication device 20.

[0084] Specifically, according to the first embodiment, the first wireless communication device 10 transmits a first signal to instruct the second wireless communication device 20 to change the time interval of the intermittent drive, and a second signal to instruct the second wireless communication device 20 to execute a function. The second wireless communication device 20 receives the signal transmitted by the first wireless communication device 10 by intermittently driving at a predetermined time interval. In addition, the second wireless communication device 20 includes a reception mode switching unit 25 that switches the reception mode of the second wireless communication device 20 between a first reception mode in which the first signal is intermittently driven at a first time interval to receive the first signal, and a second reception mode in which the second signal is intermittently driven at a second time interval shorter than the first time interval to receive the second signal. This allows the second wireless communication device 20 to reduce power consumption by intermittently driving at a long time interval when high-speed responsiveness is not required, and to intermittently drive at a short time interval when high-speed responsiveness is required. Therefore, the second wireless communication device 20 can reduce power consumption without sacrificing responsiveness.

[0085] According to the first embodiment, the first signal may include time interval designation information that designates the length of the time interval of the intermittent drive. In this case, the reception mode switching unit 25 changes the length of the first time interval according to the time interval designation information. This allows the second wireless communication device 20 to switch between the first reception mode and the second reception mode without changing the hardware configuration.

[0086] Also, according to the first embodiment, the first signal may include device designation information for designating a second wireless communication device 20 that commands a change in the time interval of intermittent drive among two or more second wireless communication devices 20. In this case, when the second wireless communication device 20 receives the first signal and the device designation information designates the device itself, the reception mode switching unit 25 switches from the first reception mode to the second reception mode. This allows a second wireless communication device 20 that requires high-speed response among the two or more second wireless communication devices 20 to be selectively intermittently driven in the second reception mode.

[0087] Furthermore, according to the first embodiment, the wireless communication system 1 may further include an intermittent operation management unit 30 that manages the timing at which the first wireless communication device 10 transmits the second signal to the second wireless communication device 20. In this case, the intermittent operation management unit 30 causes the first wireless communication device 10 to transmit the first signal to the second wireless communication device 20 at a timing prior to the timing at which the first wireless communication device 10 transmits the second signal. This enables the first wireless communication device 10 to improve the responsiveness of the second wireless communication device 20 when the timing to execute a function approaches.

[0088] According to the first embodiment, the wireless communication system 1 may be applied to a picking system. In this case, the second wireless communication device 20 includes a notification unit 26 that is provided corresponding to the picking target and notifies the position of the picking target. The intermittent operation management unit 30 predicts the timing at which the first wireless communication device 10 transmits a second signal to the second wireless communication device 20 to instruct the second wireless communication device 20 to notify the position of the picking target, based on the picking schedule information. In addition, the intermittent operation management unit 30 causes the first wireless communication device 10 to transmit the first signal to the second wireless communication device 20 at a timing prior to the predicted timing. This allows the first wireless communication device 10 to improve the responsiveness of the second wireless communication device 20 when the timing to turn on or off the notification unit 26 is approaching.

[0089] The embodiments of the present invention have been described above with reference to the drawings (FIGS. 1 to 6). However, the present invention is not limited to the above-described embodiments, and can be embodied in various forms without departing from the spirit of the present invention. Modifications 1 to 4 are described below.

[0090] <Variation 1> In the first embodiment, the length of the first time interval is one type, 2000 ms, but there may be multiple types. The first wireless communication device 10 may set the length of the first time interval differently for two or more second wireless communication devices 20. Even with this configuration, the first wireless communication device 10 can improve the responsiveness of the second wireless communication device 20 when the timing to execute a function approaches.

[0091] For example, the first wireless communication device 10 instructs the second wireless communication device 20-1, which corresponds to a part that has been picked, to change the first time interval to 4000 ms in accordance with the picking schedule 62. The first wireless communication device 10 also instructs the second wireless communication devices 20-6 and 20-5, which correspond to parts to be picked next, to change the first time interval to 2000 ms.

[0092] For example, the first wireless communication device 10 may set the length of the first time interval when the lights in a logistics warehouse or the like are on to be different from the length of the first time interval when the lights are off.

[0093] For example, the first wireless communication device 10 may set the length of the first time interval when the current time is within a picking operation time to be different from the length of the first time interval when the current time is outside the picking operation time.

[0094] <Variation 2> In the first embodiment, the intermittent operation management unit 30 is configured to cause the first wireless communication device 10 to transmit the first signal to the second wireless communication device 20 at a timing that is set in advance of the picking operation order and is earlier than the timing at which the first wireless communication device 10 transmits the second signal to the second wireless communication device 20, but is not limited to this configuration. For example, the intermittent operation management unit 30 may cause the first wireless communication device 10 to transmit the first signal to the second wireless communication device 20 at a timing that is set in advance of the timing at which the first wireless communication device 10 transmits the second signal to the second wireless communication device 20. Even with this configuration, the first wireless communication device 10 can improve the responsiveness of the second wireless communication device 20 when the picking timing is approaching.

[0095] Specifically, the intermittent operation management unit 30 predicts the time when a part corresponding to the second wireless communication device 20 will be picked. The intermittent operation management unit 30 causes the first wireless communication device 10 to transmit a beacon including a first signal for switching the reception mode of the second wireless communication device 20 from the first reception mode to the second reception mode at a timing a preset time before the predicted picking time. When the predicted picking time arrives, the intermittent operation management unit 30 causes the first wireless communication device 10 to transmit a beacon including a second signal for turning on the notification unit 26 of the second wireless communication device 20.

[0096] <Variation 3> In the first embodiment, the intermittent operation management unit 30 predicts the switching timing between the first and second reception modes for each of the second wireless communication devices 20, but the first wireless communication device 10 may predict the switching timing. For example, the first wireless communication device 10 transmits a first signal to a second wireless communication device 20 for which the time to transmit the second signal is approaching, based on a schedule (e.g., picking schedule information) for transmitting a second signal to two or more second wireless communication devices 20.

[0097] <Modification 4> In the first embodiment, the function of the second wireless communication device 20 is the notification unit 26, but the function of the second wireless communication device 20 is not limited to this. For example, if the second wireless communication device 20 is configured to include a sensor, the second control unit 23 switches the sensor on and off in accordance with the second signal transmitted by the first wireless communication device 10. [Industrial Applicability]

[0098] The present invention is suitable for use in a star-topology wireless communication system, and also suitable for use in a picking system that supports part picking operations in logistics warehouses, factories, and the like. [Explanation of symbols]

[0099] 1. Wireless communication systems 10 First wireless communication device 11 First Radio Communication Division 12 First Antenna 13 First Control Section 14 1st memory section 15 Communications Department 20, 20-1 to 20-6 Second wireless communication device 21 Second Radio Communication Division 22 Second Antenna 23 Second Control Section 24 2nd memory section 25 Receiving mode switching section 26. Notification Department 30 Intermittent operation control unit 31 Third memory section 32 Communications Department 50 workers 51 Trolley 52 Shelf 61,62 Picking Schedule

Claims

1. A first wireless communication device; one or more second wireless communication devices that receive signals transmitted by the first wireless communication device by intermittently driving the second wireless communication device at predetermined time intervals; Equipped with the first wireless communication device transmits a first signal to the second wireless communication device to instruct the second wireless communication device to change a time interval of the intermittent drive, and a second signal to instruct the second wireless communication device to execute a function; the second wireless communication device includes a reception mode switching unit that switches a reception mode of the second wireless communication device between a first reception mode in which the first signal is received by intermittently driving the second signal at a first time interval and a second reception mode in which the second signal is received by intermittently driving the second signal at a second time interval that is shorter than the first time interval, The second wireless communication device is two or more, the first signal includes device designation information that designates a second wireless communication device that is to command a change in the time interval of the intermittent drive, among the two or more second wireless communication devices; the reception mode switching unit switches from the first reception mode to the second reception mode when the second wireless communication device receives the first signal and when the device designation information designates the device itself; A wireless communication system in which the first wireless communication device transmits the first signal to the second wireless communication device when the time to transmit the second signal is approaching based on a schedule for transmitting the second signal to two or more of the second wireless communication devices.

2. the first signal includes time interval designation information that designates a length of a time interval of the intermittent driving, The wireless communication system according to claim 1 , wherein the reception mode switching unit changes the length of the first time interval in accordance with the time interval designation information.

3. The wireless communication system according to claim 1 , wherein the first time interval is different for two or more of the second wireless communication devices.

4. A first wireless communication device; one or more second wireless communication devices that receive signals transmitted by the first wireless communication device by intermittently driving the second wireless communication device at predetermined time intervals; Equipped with the first wireless communication device transmits a first signal to the second wireless communication device to instruct the second wireless communication device to change a time interval of the intermittent drive, and a second signal to instruct the second wireless communication device to execute a function; the second wireless communication device includes a reception mode switching unit that switches a reception mode of the second wireless communication device between a first reception mode in which the first signal is received by intermittently driving the second signal at a first time interval and a second reception mode in which the second signal is received by intermittently driving the second signal at a second time interval that is shorter than the first time interval, an intermittent operation management unit that manages a timing at which the first wireless communication device transmits the second signal to the second wireless communication device, the intermittent operation management unit causes the first wireless communication device to transmit the first signal to the second wireless communication device at a timing prior to a timing at which the first wireless communication device transmits the second signal; A picking system including a wireless communication system, The second wireless communication device includes a notification unit that is provided corresponding to the picking target and notifies the position of the picking target, A picking system in which the intermittent operation management unit predicts, based on picking schedule information, a timing when the first wireless communication device will transmit the second signal to the second wireless communication device, instructing the second wireless communication device to notify the location of the item to be picked, and causes the first wireless communication device to transmit the first signal to the second wireless communication device at a timing prior to the predicted timing.

5. The picking system according to claim 4, wherein the intermittent operation management unit causes the first signal to be transmitted from the first wireless communication device to the second wireless communication device at a timing a predetermined time before the predicted timing or before a predetermined picking work order.

6. A first wireless communication device that transmits a signal to one or more second wireless communication devices that are intermittently driven at a predetermined time interval to receive a signal, and communicates with the second wireless communication devices, Transmitting a first signal to the second wireless communication device to instruct the second wireless communication device to change a time interval of the intermittent drive, and a second signal to instruct the second wireless communication device to execute a function; The second wireless communication device is two or more, A first wireless communication device that transmits the first signal to the second wireless communication device when the time to transmit the second signal is approaching based on a schedule for transmitting the second signal to two or more of the second wireless communication devices.

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