Data transmission device, data collection device, and data collection system

Abstract

To provide a technology for reliable communication during data recovery.SOLUTION: A data transmission device 30 includes an antenna 31 and a communication unit 32. The communication unit 32 modulates the reflected wave of an unmodulated signal received by the antenna 31 and sequentially transmits a plurality of ordered data blocks. When the communication unit 32 has completed the transmission of up to the nth data block, and when the communication unit receives an unmodulated signal in the first standby state waiting for the resumption of reception of the unmodulated signal, the communication unit 32 transmits the data blocks in order from n-nd, where nd is a predetermined value and is also 0 or a natural number.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to techniques for retrieving data from devices that store data, such as data loggers. [Background technology]

[0002] For example, Patent Document 1 discloses an observation system for collecting observation data from observation equipment. This observation system includes multiple observation equipment installed at an observation location and a multicopter equipped with power transmission and communication equipment. The multicopter flies autonomously from a base station to above the observation equipment. When the multicopter reaches above the observation equipment, the power transmission and communication equipment supplies power to the observation equipment and collects the observation data from the observation equipment. When the power transmission and communication equipment finishes supplying power and collecting the observation data, the multicopter returns to the base station. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6666663 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 does not specifically disclose how the power transmission and communication equipment and the observation equipment will operate if a communication error occurs between the power transmission and communication equipment and the observation equipment when the power transmission and communication equipment retrieves observation data from the observation equipment.

[0005] An object of the present invention is to provide a technique for performing reliable communication when retrieving data. [Means for solving the problem]

[0006] The data transmission device of the present invention includes an antenna and a communication unit, and the communication unit modulates a reflected wave of an unmodulated signal received by the antenna to transmit a plurality of ordered data blocks in order. When the communication unit has completed transmission of the nth data block and receives an unmodulated signal in a first standby state in which it waits for the resumption of reception of the unmodulated signal, the communication unit d Send data blocks in order starting from the nth block, where d is a predetermined value, which is 0 or a natural number.

[0007] The data recovery device of the present invention comprises an antenna, a transmitter, a receiver, and a data recovery control unit, wherein the transmitter transmits an unmodulated signal from the antenna based on an instruction from the data recovery control unit, the receiver receives a data block carried on a reflected wave of the unmodulated signal at the antenna, and if no error is detected in the received data block, outputs the received data block, and if an error is detected in the received data block, does not output the received data block, and the data recovery control unit stores the acquired data block if it acquires a data block from the receiver within a predetermined period, and instructs the transmitter to temporarily stop transmitting the unmodulated signal if it does not acquire a data block from the receiver within the predetermined period.

[0008] The data collection system of the present invention comprises the data transmission device of the present invention and the data collection device of the present invention. [Effects of the Invention]

[0009] According to the present invention, reliable communication can be performed when retrieving data. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a conceptual diagram of a data collection system 10 according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram of the data collection device 20 according to the first embodiment. [Figure 3]FIG. 3 is a block diagram of a data transmission device 30 according to the first embodiment. [Figure 4] FIG. 4 is a state transition diagram showing the data collection process of the data collection control unit 24 according to the first embodiment. [Figure 5] FIG. 5 is a state transition diagram showing the data transmission process of the communication control unit 36 ​​according to the first embodiment. [Figure 6] FIG. 6 is a first example of a timing chart showing the data collection process of the data collection system 10 according to the first embodiment. [Figure 7] FIG. 7 is a second example of a timing chart showing the data collection process of the data collection system 10 according to the first embodiment. [Figure 8] FIG. 8 is a third example of a timing chart showing the data collection process of the data collection system 10 according to the first embodiment. [Figure 9] FIG. 9 is a diagram for explaining how to determine nd. [Figure 10] FIG. 10 is a state transition diagram showing the data transmission process of the communication control unit 36 ​​according to the modified example of the first embodiment. [Figure 11] FIG. 11 is an example of a timing chart showing the data collection process of the data collection system 10 according to the modified example of the first embodiment. [Figure 12] FIG. 12 is a state transition diagram showing the data transmission process of the communication control unit 36 ​​according to the second embodiment. [Figure 13] FIG. 13 is an example of a timing chart showing the data collection process of the data collection system 10 according to the second embodiment. [Figure 14] FIG. 14 is a state transition diagram showing the data transmission process of the communication control unit 36 ​​according to the modified example of the second embodiment. [Figure 15] FIG. 15 is an example of a timing chart showing the data collection process of the data collection system 10 according to the modified example of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments for carrying out the present invention will be described. Each embodiment is an example, and partial substitution or combination of the configurations shown in different embodiments is possible. In each embodiment, differences from the previous embodiments will be described. In particular, similar effects resulting from similar configurations will not be mentioned in each embodiment.

[0012] First Embodiment FIG. 1 is a conceptual diagram of a data collection system 10 according to a first embodiment of the present invention. The data collection system 10 includes a drone 11, a data collection device 20, an observation device 12, and a data transmission device 30. The data collection device 20 is mounted on the drone 11. The data transmission device 30 is installed near the observation device 12 and communicates with the observation device 12 via wired or wireless communication. The observation device 12 and the data transmission device 30 are installed, for example, at an observation site on the ground.

[0013] The drone 11 autonomously flies from a base station (not shown) to the sky above the data transmission device 30, and then hovers above the data transmission device 30. When the drone 11 starts hovering, the data collection device 20 transmits an unmodulated signal to the data transmission device 30. This unmodulated signal is, for example, a microwave. In this specification, microwaves are electromagnetic waves having a frequency of 300 MHz to 300 GHz. The data transmission device 30 wakes up upon receiving the unmodulated signal and transitions from sleep mode to operating mode. The data transmission device 30 then reads observation data from the observation device 12 and transmits the observation data to the data collection device 20 via backscattering communication. The transmitted data consists of multiple ordered data blocks, and the data blocks are transmitted in order. The data collection device 20 receives and stores the observation data. When the data collection device 20 finishes collecting the observation data, the drone 11 autonomously flies and returns to the base station.

[0014] It should be noted that data collection may be performed when the drone 11 has landed, rather than when the drone 11 is hovering.

[0015] 2 is a block diagram of the data collection device 20 according to the first embodiment. The data collection device 20 includes antennas 211 and 212, a transmitter 22, a receiver 23, a data collection control unit 24, and a storage unit 25.

[0016] The transmitter 22 transmits an unmodulated signal from the antenna 211 based on a command from the data collection control unit 24. The transmitter 22 conforms to the standard for specified low-power radio stations established by the Association of Radio Industries and Businesses (ARIB) and performs carrier sense before starting transmission, transmits for a predetermined time or less, and then stops transmission for a predetermined time or more. For example, the transmitter 22 conforms to the standard ARIB STD-T107 for specified low-power radio stations, 920 MHz band mobile unit identification radio equipment, established by the Association of Radio Industries and Businesses. Specifically, the transmitter 22 stops transmitting the unmodulated signal for time T2 every time T1. The transmitter 22 also stops transmission in accordance with the standard independently of a command from the data collection control unit 24.

[0017] It is not essential that the transmitter 22 conforms to the standard for specified low-power radio stations.

[0018] The receiver 23 has an RF circuit, an A / D conversion circuit, and a data processing unit. The RF circuit demodulates the signal received by the antenna 212. The A / D conversion circuit converts the signal extracted by the RF circuit into a digital signal. The data processing unit processes the data included in the signal output from the A / D conversion circuit. The data processing unit is composed of a CPU, memory, etc., and performs predetermined processing by executing a program.

[0019] The receiver 23 receives the data block carried on the reflected wave of the unmodulated signal (i.e., unmodulated carrier wave) at the antenna 212. The receiver 23 performs error detection on the received data block in its data processing unit. The error detection method may be, for example, a checksum, a parity check, or a CRC. If the receiver 23 does not detect an error in the received data block, it outputs the received data block, and if it detects an error in the received data block, it does not output the received data block.

[0020] Although the transmitter 22 and the receiver 23 use antennas 211 and 212, respectively, they may share one antenna.

[0021] The data collection control unit 24 controls the entire data collection device 20. The data collection control unit 24 obtains data blocks in which no errors have been detected from the receiver 23 and stores the data blocks. The data collection control unit 24 also outputs a transmission control signal to the transmitter 22. The data collection control unit 24 commands the transmitter 22 to start transmission by raising the transmission control signal, and commands the transmitter 22 to stop transmission by lowering the transmission control signal. Furthermore, the data collection control unit 24 communicates with the drone 11 as appropriate. The data collection control unit 24 is composed of a CPU, memory, etc., and performs predetermined processing by executing a program.

[0022] The data collection control unit 24 temporarily stores the data block in its own memory, and after data collection is complete, writes the data block to the storage unit 25. The storage unit 25 is a non-volatile memory such as an SD memory card.

[0023] 3 is a block diagram of a data transmission device 30 according to the first embodiment. The data transmission device 30 includes an antenna 31 and a communication unit 32. The communication unit 32 includes a rectifying modulation circuit 33, a voltage detection circuit 34, a voltage holding circuit 35, and a communication control unit 36.

[0024] The rectifying and modulating circuit 33 rectifies and converts the unmodulated signal received by the antenna 31 into a DC voltage and outputs the DC voltage to the voltage detecting circuit 34. The rectifying and modulating circuit 33 also modulates the reflected wave of the unmodulated signal received by the antenna 31 by changing the load on the antenna 31 based on the modulating signal ms output from the communication control unit 36.

[0025] The voltage detection circuit 34 outputs a voltage V to the voltage holding circuit 35 and the communication control unit 36 ​​in accordance with the output voltage of the rectification modulation circuit 33. nms When the output voltage of the rectifying / modulating circuit 33 is higher than the reference voltage, the voltage detection circuit 34 outputs the voltage V nmsis set to high level, and when the output voltage of the rectifier modulation circuit 33 is lower than the reference voltage, the voltage V nms Set to low level.

[0026] The voltage holding circuit 35 has an RS latch or an RS flip-flop, and has a set terminal S, a reset terminal R, and a power supply terminal F. The voltage holding circuit 35 holds the voltage V nms rises to a high level, that is, when the voltage at the set terminal S rises to a high level, the voltage holding circuit 35 connects the power supply terminal F to a power source (not shown) and maintains this state, thereby supplying power to the communication control unit 36. Furthermore, when the communication control unit 36 ​​raises the voltage at the reset terminal R to a high level, the voltage holding circuit 35 stops the connection between the power supply terminal F and the power source, thereby terminating the supply of power to the communication control unit 36.

[0027] The voltage holding circuit 35 may be comprised of other types of latches or flip-flops.

[0028] The communication control unit 36 ​​controls the voltage V nms That is, the communication control unit 36 ​​determines the reception state of the unmodulated signal by monitoring the voltage V nms is at a high level, it is determined that an unmodulated signal is being received, and the voltage V nms is at a low level, it is determined that an unmodulated signal is not being received. The communication control unit 36 ​​also reads observation data from the observation device 12 and processes the observation data for transmission. The communication control unit 36 ​​then transmits the observation data by outputting a modulated signal ms carrying the observation data to the rectification modulation circuit 33. The communication control unit 36 ​​is composed of a CPU, memory, etc., and performs predetermined processing by executing a program.

[0029] When the drone 11 arrives in the sky above the data transmission device 30, it notifies the data collection control unit 24 of the data collection device 20 that it has arrived at its destination. Upon receiving this notification, the data collection control unit 24 commands the transmitter 22 to start transmission. Upon receiving this command, the transmitter 22 starts transmitting an unmodulated signal to the data transmission device 30.

[0030] When the antenna 31 of the data transmitter 30 receives an unmodulated signal, the rectifier / modulator circuit 33 outputs a DC voltage, and the voltage detector circuit 34 detects the voltage V nms to a high level, the voltage holding circuit 35 supplies power to the communication control unit 36, and the communication control unit 36 ​​transitions from sleep mode to operating mode. The communication control unit 36 ​​then reads the observation data from the observation device 12, processes the observation data for transmission, and outputs a modulated signal ms to the rectifying and modulating circuit 33 to notify the data collection device 20 that preparations for transmission are complete.

[0031] Upon receiving the notification, the data collection control unit 24 of the data collection device 20 commands the transmitter 22 to stop transmission, and then commands the transmitter 22 to start transmission again. After notifying the completion of preparation for transmission, the communication control unit 36 nms When it detects the rising edge of

[0032] The notification of completion of preparation for transmission is sent so that the transmission stop specified by the standard does not occur between the notification of completion of preparation for transmission and the transmission stop caused by that notification.

[0033] FIG. 4 is a state transition diagram showing the data collection process of the data collection control unit 24 according to the first embodiment. FIG. 5 is a state transition diagram showing the data transmission process of the communication control unit 36 ​​according to the first embodiment. FIG. 6 is a first example of a timing chart showing the data collection process of the data collection system 10 according to the first embodiment. In the first example shown in FIG. 6, the data collection device 20 and the data transmission device 30 are communicating normally. FIG. 7 is a second example of a timing chart showing the data collection process of the data collection system 10 according to the first embodiment. In the second example shown in FIG. 7, the data collection device 20 detects an error in a data block. FIG. 8 is a third example of a timing chart showing the data collection process of the data collection system 10 according to the first embodiment. In the third example shown in FIG. 8, the power transmitted from the data collection device 20 to the data transmission device 30 is temporarily reduced. FIG. 9 shows n d9 is a diagram for explaining how to determine the time period during which each data block is transmitted from the data transmitting device 30 to the data collecting device 20.

[0034] 6 to 8, "unmodulated signal" indicates a period during which the transmitter 22 transmits and a period during which the transmitter 22 stops transmitting. A period during which the transmitter 22 performs carrier sensing is not shown. nms " is the voltage V nms "Data transmission" indicates the period during which each data block is transmitted from the data transmitting device 30 to the data collecting device 20. "Error detection" indicates the period during which the receiver 23 performs error detection. "Data acquisition" indicates the period during which the data collection control unit 24 acquires and stores the data blocks. "Transmission control signal" indicates the waveform of the transmission control signal.

[0035] As shown in FIG. 4, when the data collection control unit 24 receives a notification that the preparation for transmission is complete and then commands the transmitter 22 to start transmission again, it sets i to 2 and n sm Set to 0. i represents the mode. n sm represents the number of data blocks acquired by the data collection control unit 24 from the start or restart of transmission of the unmodulated signal to the present without stopping transmission of the unmodulated signal.

[0036] The data collection control unit 24 again commands the transmitter 22 to start transmission, and then waits for the acquisition of a data block (S11, S12). ad If a data block is acquired within [i], it stores the data block in its own memory and sm Increase the value of by 1. Then, n sm If n is equal to 1, set i to 0 and return to state S12. sm N s If it is equal to , set i to 1 and n sm Set 0 and return to state S12. Otherwise, return to state S12. T ad[0] represents the time that the data collection control unit 24 waits for the next data block after acquiring and storing the data block, without stopping the transmission of the unmodulated signal. ad [1] represents the time it takes for the data collection control unit 24 to wait for the next data block after acquiring and storing the data block and stopping the transmission of the unmodulated signal according to the standard. ad [2] represents the time it takes for the data collection control unit 24 to wait for a data block after instructing the transmitter 22 to start transmission. s represents the number of data blocks that the data collection control unit 24 acquires from the start or restart of transmission of the unmodulated signal until time T1, assuming that communication is performed normally. s Assuming that communication is performed normally, N represents the number of data blocks that the communication control unit 36 ​​completes transmitting within a time T1 after starting or restarting transmission of the unmodulated signal. s is a natural number. In the examples shown in Figures 6 to 8, N s is set to 6.

[0037] When the data collection control unit 24 acquires a data block that has already been acquired, the data collection control unit 24 may discard the acquired data block without saving it.

[0038] The data collection control unit 24 detects a time T ad If no data block is received within the time [i], the transmitter 22 is instructed to stop transmitting, and the time T ss (S11, S13) ss After the time has elapsed, the transmitter 22 is instructed to resume transmission, i is set to 2, and n sm Set 0 to T and return to state S12. ss is the time during which the data recovery control unit 24 lowers the transmission control signal to low level when it detects a missing data block.

[0039] The stop of transmission of the unmodulated signal is delayed from the command, and the start of transmission of the unmodulated signal is delayed from the command.

[0040] When the data collection control unit 24 receives a notification of data transmission completion from the data transmission device 30 in the state S12, or when a time T em If data collection is not completed by T, data collection will end. em represents the time the data collection control unit 24 waits before terminating the data collection process.

[0041] As shown in FIG. 5, the communication control unit 36 ​​notifies the data collection device 20 that preparation for transmission is complete, and then turns on the voltage V nms When the rising edge of n is detected, ss is set to 0, and the n+1th data block is transmitted (S21). n represents the number of data blocks that the communication control unit 36 ​​considers to have transmitted up to now. n ss represents the number of data blocks transmitted by the communication control unit 36 ​​from the start or restart of transmission of the unmodulated signal to the present without stopping transmission of the unmodulated signal.

[0042] The communication control unit 36 ​​controls the voltage V nms When the falling edge of is detected, the transmission of the n+1th data block is stopped, that is, the output of the modulated signal ms carrying the n+1th data block is stopped, and the voltage V nms The state S22 is an example of the "first standby state" of the present invention. nms If a rising edge is detected, 0 and nn d Set n to the smaller of -1 and n ss is set to 0 and transition to state S21. es The voltage V nms If the rising edge of n is not detected, the data transmission process ends. d is T d T db It corresponds to the integer part of the quotient when dividing by T, and is either 0 or a natural number. dAssuming that the receiver 23 detects an error in a data block, T is the time from when the communication control unit 36 ​​completes transmission of that data block to when the communication control unit 36 ​​stops transmitting the data block due to the error in that data block. db is the time it takes to transmit one data block. In the examples shown in Figures 6 to 8, n d is set to 0. In the example shown in FIG. d is set to 1. T es represents the time that the communication control unit 36 ​​waits before terminating the data transmission process.

[0043] When the communication control unit 36 ​​completes transmission of the (n+1)th data block, ss Increase the value of by 1.

[0044] Then, the communication control unit 36 ​​determines whether n is equal to N and ss N s If it is not equal to N, the process returns to state S21. N represents the total number of data blocks transmitted by the communication control unit 36.

[0045] The communication control unit 36 ​​controls n, n ss After incrementing the value of by 1, if n is not equal to N and n ss N s If the nth data block is transmitted, the time T sd (S23) The time T sd After the time has elapsed, the high-level voltage V nms The communication control unit 36 ​​waits for the detection of the high-level voltage V nms If detected, n ss 0 and transition to state S21. The voltage V nms If no T is detected, the state transitions to state S22. sd is T sd <T s <T sd +δ, where T s=T1+T2-T db ×N s δ is the voltage V that is at a high level when the communication control unit 36 ​​is in state S24. nms This is the time to wait for the detection of

[0046] The communication control unit 36 ​​controls n, n ss After incrementing the value of n by 1, if n is equal to N, the data collection device 20 is notified of the completion of data transmission (S25), and the data transmission process is terminated.

[0047] Here, time T ss The setting value of time T ss is set long enough so that the following conditions are met: First, the time T rt is time T sd Above +δ. T rt Assuming that the data recovery control unit 24 detects a missing data block, the voltage V nms represents the time during which the signal is at a low level due to the loss of that data block. Second, assuming that the data collection control unit 24 detects the loss of a data block, after issuing a command to resume transmission of the unmodulated signal, the data collection control unit 24 acquires only the data blocks that the communication control unit 36 ​​started transmitting after issuing the command to resume transmission.

[0048] Furthermore, the constants used in the data collection system 10 are as follows: T1, T2, N s , T ad [i], T ss , T em , T sd ,δ,n d , T es The value of is predetermined and does not change during data collection. The value of N is determined during transmission preparation and does not change during data collection.

[0049] 6, when the data collection control unit 24 raises the transmission control signal to a high level, the transmitter 22 starts transmitting an unmodulated signal. nmsWhen the receiver 23 detects the rising edge of the transmission control signal, it transmits the data blocks in order starting from the first one. When the receiver 23 receives a data block, it performs error detection on the data block. When the data collection control unit 24 acquires a data block from the receiver 23, it stores the data block. Here, the data collection control unit 24 detects the rising edge of the transmission control signal from the time T ad [2] for the first data block. In addition, the data collection control unit 24 waits for the time T ad The communication control unit 36 ​​waits for the next data block for a time T[0]. After transmitting the sixth data block, the communication control unit 36 ​​stops transmitting data blocks. The transmitter 22 transmits an unmodulated signal for a time T1, and then stops transmitting the unmodulated signal for a time T2. The communication control unit 36 ​​waits for a time T[0] after completing transmission of the sixth data block. sd Then, the voltage V remains high until the time δ has elapsed. nms When the receiver 23 detects an error in the seventh data block, it starts transmitting the seventh data block. When the receiver 23 receives the seventh data block, it performs error detection on the data block. When the data collection control unit 24 acquires the seventh data block from the receiver 23, it stores the data block. Here, the data collection control unit 24 acquires and stores the sixth data block after a time T ad [1] waits for the seventh data block. The data collection process continues in the same way.

[0050] In the second example shown in Fig. 7, the receiver 23 detects an error in the tenth block data. The data collection control unit 24 receives and stores the ninth data block and then returns to the ad In order to obtain the block data within [0], the transmission control signal is set to low level for a time T ss The transmitter 22 temporarily stops transmitting the unmodulated signal in response to the falling edge and subsequent rising edge of the transmission control signal. The communication control unit 36 ​​reduces the voltage V nms The communication control unit 36 ​​then detects the falling edge of the voltage Vnms When it detects the rising edge of , it transmits data blocks in order starting from the 10th.

[0051] In the third example shown in FIG. b1 From t b2 An unmodulated signal is transmitted until the voltage V nms is at a low level. nms The falling edge of b1 Then, the voltage V nms The rising edge of time t b2 The receiver 23 detects the error and starts transmitting the eighth data block. Since the receiver 23 does not receive the entire ninth data block, it does not perform error detection on the ninth data block. The data collection control unit 24 detects the error and starts transmitting the eighth data block. ad Since the ninth data block is not acquired within [0], the transmission control signal is set to low level for time T ss The transmitter 22 temporarily stops transmitting the unmodulated signal in response to the falling edge and subsequent rising edge of the transmission control signal. The communication control unit 36 ​​reduces the voltage V nms The falling edge of V is detected and the transmission of the eighth data block is stopped. nms When the rising edge of , the 7th data block is detected and transmitted in order.

[0052] When data collection is completed, the data collection control unit 24 of the data collection device 20 stops transmission from the transmitter 22 and notifies the drone 11 of the completion of data collection. Then, the data collection control unit 24 writes the data block stored in its own memory to the storage unit 25. When the drone 11 receives the notification of the completion of data collection, it returns to the base station. The communication control unit 36 ​​of the data transmission device 30 controls the voltage V nms If this is detected continuously for a predetermined period of time or more, the device will enter sleep mode.

[0053] 10 is a state transition diagram showing the data transmission process of the communication control unit 36 ​​according to the modified example of the first embodiment. The data transmission process according to the modified example of the first embodiment differs from the data transmission process according to the first embodiment in the following respects. That is, the communication control unit 36 ​​completes transmission of the (n+1)th data block and ss After increasing the value of by 1, if n is not equal to N, return to S21. Also, during the transmission of the n+1th data block, the voltage V nms Detect the falling edge of and ss N s If the nth data block is transmitted, the time T sd (S23) The voltage V nms Detect the falling edge of and ss N s If it is not equal to, the state transitions to state S22.

[0054] 11 is an example of a timing chart showing the data collection process of the data collection system 10 according to the modified example of the first embodiment. The communication control unit 36 ​​increases the voltage V nms The falling edge of V is detected and the transmission of the seventh data block is stopped. nms When the rising edge of CLK is detected, the transmission of the seventh data block begins.

[0055] According to the first embodiment, if the data recovery device 20 detects an error in a received data block or if a data block that is scheduled to be received is not received within a predetermined time, the data recovery device 20 temporarily stops transmitting the unmodulated signal. After resuming transmission of the unmodulated signal, the data transmission device 30 transmits or retransmits the data block. By correcting the communication error in this manner, reliable communication can be achieved.

[0056] Furthermore, the data collection device 20 and the data transmission device 30 do not need to perform two-way communication. The transmitter 22 does not need to transmit a modulated signal, and the data transmission device 30 does not need a receiver. This simplifies the collection process and system configuration.

[0057] Second Embodiment The data collection system according to the second embodiment of the present invention differs from the data collection system according to the first embodiment of the present invention in terms of data transmission processing. The configuration of the data collection system according to the second embodiment is substantially the same as the configuration of the data collection system according to the first embodiment of the present invention shown in Figures 1 to 3. Therefore, the components of the data collection system according to the second embodiment that are substantially the same as the components of the data collection system according to the first embodiment are assigned the same reference numerals as those components of the data collection system according to the first embodiment, and a description of the configuration of the data collection system according to the second embodiment will be omitted.

[0058] 12 is a state transition diagram showing the data transmission process of the communication control unit 36 ​​according to the second embodiment. The data transmission process according to the second embodiment differs from the data transmission process according to the first embodiment in the following respects. That is, the communication control unit 36 ​​completes transmission of the (n+1)th data block and ss After incrementing the value of by 1, if n is not equal to N and n ss N s If equal to, the voltage V nms The rising edge of the signal is detected (S22).

[0059] 13 is an example of a timing chart showing the data collection process of the data collection system 10 according to the second embodiment. When the communication control unit 36 ​​completes the transmission of the sixth data block, the voltage V nms Wait for the voltage V nms When it detects a rising edge, it transmits data blocks in order, starting from the sixth.

[0060] 14 is a state transition diagram showing the data transmission process of the communication control unit 36 ​​according to the modified example of the second embodiment. The data transmission process according to the modified example of the second embodiment differs from the data transmission process according to the second embodiment in the following respects. That is, when the communication control unit 36 ​​completes transmission of the (n+1)th data block, it increments the value of n by 1 and returns to state S21. In addition, the communication control unit 36 ss , N s does not need to be defined.

[0061] 15 is an example of a timing chart showing the data collection process of the data collection system 10 according to the modified example of the second embodiment. The communication control unit 36 ​​increases the voltage V nms The falling edge of V is detected and the transmission of the seventh data block is stopped. nms When the rising edge of CLK is detected, the transmission of the sixth data block begins.

[0062] According to the second embodiment, the recovery process can be further simplified.

[0063] In another embodiment, the data collection device 20 may be mounted on another moving body instead of the drone 11.

[0064] Alternatively, the data collection device 20 may be installed inside a building, for example, instead of being mounted on a mobile object. The data collection device 20 may then transmit the observation data to a base station, for example, using a wide area network.

[0065] Furthermore, the data transmission device 30 may communicate with another data storage device instead of the observation device 12 and transmit other data instead of the observation data.

[0066] Finally, the above description of the embodiments is illustrative in all respects and is not restrictive. Variations and modifications are possible for those skilled in the art. The scope of the present invention is defined not by the above embodiments but by the claims. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope of the claims and their equivalents. [Explanation of symbols]

[0067] F...Power supply terminal R...Reset terminal S...Set terminal 10...Data collection system 11. Drone 12...Observation equipment 20...Data collection device 22...Transmitter 23...Receiver 24...Data collection control unit 25...Storage section 30...Data transmission device 31...Antenna 32…Communications Department 33... Rectification modulation circuit 34...Voltage detection circuit 35...Voltage holding circuit 36...Communication control unit 211,212...antenna

Claims

1. An antenna and a communication unit are provided, the communication unit modulates a reflected wave of the unmodulated signal received by the antenna and transmits a plurality of ordered data blocks in sequence; When the communication unit has completed transmission of the n-th data block and receives an unmodulated signal in a first waiting state in which it waits for the resumption of reception of the unmodulated signal, n-n d The data blocks are transmitted in order from the nth block, where d is a predetermined value, and is 0 or a natural number.

2. The communication unit is s If the unmodulated signal is no longer received before the transmission of the data blocks is completed without interruption, the state transitions to the first waiting state, s is a predetermined value and is a natural number, The communication unit is s Stop transmitting the data blocks after completing the transmission of the data blocks without stopping halfway, The communication unit s A predetermined time T sd After the lapse of time, the state transitions to a second waiting state in which the state waits for reception of an unmodulated signal, the communication unit has completed transmission of the n-th data block and, when receiving an unmodulated signal in the second standby state, transmits data blocks in order from the n+1-th data block; 2. The data transmitting device according to claim 1, wherein the communication unit transitions to the first standby state if it does not receive an unmodulated signal until a predetermined time δ has elapsed since the transition to the second standby state.

3. The data transmitting device according to claim 1 , wherein the communication unit transitions to the first standby state when an unmodulated signal is no longer received during transmission of a data block.

4. an antenna, a transmitter, a receiver, and a data collection control unit; the transmitter transmits an unmodulated signal from the antenna based on a command from the data collection control unit; The receiver receives the data block carried on the reflected wave of the unmodulated signal by the antenna, and if no error is detected in the received data block, outputs the received data block, and if an error is detected in the received data block, does not output the received data block; The data recovery control unit stores the acquired data block if it acquires the data block from the receiver within a predetermined period, and instructs the transmitter to temporarily stop transmitting the unmodulated signal if it does not acquire the data block from the receiver within the predetermined period.

5. A data collection system comprising: a data transmission device according to any one of claims 1 to 3; and a data collection device according to claim 4.

6. Further comprising a moving body and an observation device; the data collection device is mounted on the moving body, 6. The data collection system according to claim 5, wherein the data transmission device acquires observation data from the observation device and transmits a data block including the observation data.

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