Communication system and control device

Abstract

To stably transmit an image signal with a large data size separately from telemetry data and control signals.SOLUTION: A communication system between an unmanned vehicle and a control device simultaneously executes first wireless communication and second wireless communication, the first wireless communication being configured to transmit an image signal captured by a camera mounted on the unmanned vehicle to the control device through unidirectional communication with a first frequency band, the second wireless communication being configured to transmit control signals from the control device to the unmanned vehicle and transmit telemetry data from the unmanned vehicle to the control device through unidirectional communication with a second frequency band lower than the first frequency band.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a communication system for use in an unmanned vehicle and a control device, and to the control device. [Background technology]

[0002] In recent years, unmanned vehicles such as drones have been used in a variety of fields, and communication technologies between drones and the ground are also being developed.

[0003] The following Patent Document 1 describes a technology in which a control device mounted on an aircraft equipped with a communication device that communicates with wireless base stations over two or more frequency bands counts the number of communication errors that occur between the wireless base stations for each frequency band, switches the wireless base station that communicates over the frequency band when the communication error count value reaches or exceeds a predetermined value, and varies the timing of switching the wireless base station for each frequency band. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7126029 Summary of the Invention [Problem to be solved by the invention]

[0005] Meanwhile, the use of unmanned vehicles such as drones for purposes such as inspection, monitoring, disaster response, etc. In these cases, it is required to fly over long distances that are out of the operator's line of sight, for example, up to a distance of about 5 km, and to transmit images from the drone during flight.

[0006] The present invention proposes a system that can transmit appropriate images and the like even during such long-distance flights. [Means for solving the problem]

[0007] The communication system of the present invention is a communication system between an unmanned mobile body and a control device, which simultaneously executes a first wireless communication in which an image signal captured by a camera attached to the unmanned mobile body is transmitted to the control device via one-way communication in a first frequency band, and a second wireless communication in which a control signal is transmitted from the control device to the unmanned mobile body and telemetry data is transmitted from the unmanned mobile body to the control device via simplex communication in a second frequency band lower than the first frequency band. In other words, the transmission of image signals, which have a large amount of data, is performed by the first wireless communication, and the transmission of control signals and telemetry data is performed in parallel by the second wireless communication.

[0008] A control device according to the present invention includes a ground station that simultaneously executes a first wireless communication, which is a one-way communication in a first frequency band, and a second wireless communication, which is a simplex communication in a second frequency band lower than the first frequency band, with an unmanned mobile body, receives an image signal captured by a camera attached to the unmanned mobile body through the first wireless communication, and transmits a control signal to the unmanned mobile body and receives telemetry data from the unmanned mobile body through the second wireless communication, a first communication antenna used to receive the first wireless communication, and a second communication antenna used to transmit and receive the second wireless communication, thereby realizing a control device that is suitable for the above-mentioned communication system. Effect of the Invention

[0009] According to the communication system of the present invention, image signals, which have a large data size, can be communicated separately from telemetry data and control signals, thereby stabilizing the transmission of both. In addition, the control device of the present invention can use the first communication antenna exclusively for receiving, allowing the receiving gain to be set high, making it suitable for long-distance image transmission. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram of a communication system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of the control device according to the embodiment. [Diagram 3] FIG. 2 is a perspective view of the embodiment in a state where the control device and the tablet PC are separated. [Figure 4] FIG. 2 is a plan view of the control device according to the embodiment. [Diagram 5] FIG. 2 is a bottom view of the control device according to the embodiment. [Figure 6] FIG. 2 is a perspective view of the control device according to the embodiment with the antenna open. [Figure 7] FIG. 2 is a perspective view of the control device according to the embodiment with the antenna open. [Figure 8] FIG. 2 is a side view of the control device according to the embodiment with the antenna open. [Figure 9] FIG. 2 is a block diagram of each component constituting the communication system according to the embodiment. [Figure 10] FIG. 2 is a block diagram of a control device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described. In the following explanation, the control device 1 is referred to as being in the position when the user holds the control device 1 in front of his or her body, with the side with the controls and display screen being the top and the direction the user is facing being the front, and the directions up, down, front, back, left and right are indicated.

[0012] <1. System Overview> Figure 1 shows a drone 2 as an example of an unmanned mobile body, and a control device 1 for the drone 2. The communication system between the control device 1 and the drone 2 is a high-speed wireless transmission system capable of long-distance communication up to approximately 5 km.

[0013] A control signal is transmitted from the control device 1 to the drone 2 to control the flight of the drone 2 and the shooting operation of the camera 82 mounted on the drone 2. Image signals captured by the camera 82 and telemetry data from the drone 2 are transmitted from the drone 2 to the control device 1.

[0014] In this case, the first wireless communication and the second wireless communication are performed simultaneously in parallel between the control device 1 and the drone 2. In the first wireless communication, an image signal is transmitted from the drone 2 to the control device 1 via one-way communication using a first frequency band, for example the 5.7 GHz band. In the second wireless communication, control signals and telemetry data request signals are transmitted from the control device 1 to the drone 2, and telemetry data is transmitted from the drone 2 to the control device 1, using simplex communication in a second frequency band, for example the sub-GHz band.

[0015] The sub-GHz band of the second wireless communication is, for example, 920 MHz. The telemetry data is information obtained by various sensors on the drone side, such as altitude information, location information by GNSS (Global Navigation Satellite System), temperature information, air pressure information, attitude information of the drone 2, remaining battery information, and the like. Control signals sent from the control device 1 via the second wireless communication include control signals (control signals) for flight control of the drone 2, and control signals (camera operation signals) related to the shooting operation of the camera 82 mounted on the drone 2.

[0016] The image signal transmitted by the first wireless communication is, for example, a Full HD (Full High Definition) image, allowing high-quality images (video or still images) captured by the camera 82 of the drone 2 to be viewed on the control device 1 side.

[0017] The control device 1, which will be described in detail later, is used by attaching a separate information processing device, a tablet PC 3. The display screen of the tablet PC 3 can be used to display images based on received image signals and information based on telemetry data.

[0018] Furthermore, the control device 1 can be connected to, for example, an external monitor device 4, and can be supplied with and display an image signal received via the first wireless communication. In addition, a memory card 5, for example, can be attached to the control device 1 as a storage medium, and image signals received via the first wireless communication can be stored in the memory card 5.

[0019] <2. Structure of the control device> The structure of the control device 1 will be described with reference to FIGS.

[0020] The tablet PC 3 is detachably attached to the main body 10 of the control device 1. Figures 2 and 4 show the tablet PC 3 attached to the main body 10, and Figure 3 shows the tablet PC 3 removed from the control device 1.

[0021] The tablet PC 3 has a display screen 30 formed on the top surface of a substantially rectangular plate-like body, and a terminal section 31 (see FIG. 3) is provided on the right side surface. Accordingly, an arrangement space 15 is formed in the main body 10 of the control device 1, and the tablet PC 3 is mounted in the arrangement space 15.

[0022] In this case, the hold bar 12 is rotatably disposed on the upper side of the arrangement space 15. The hold bar 12 is bent to match the shape of the tablet PC 3, and both ends are inserted into the shaft portion 13. This allows the hold bar 12 to be rotated upward from the state shown in FIG. 3. The tablet PC 3 can be inserted into the arrangement space 15 by rotating the hold bar 12 upward.

[0023] Thereafter, the hold bar 12 is returned to its original state, so that the hold bar 12 holds the tablet PC 3 down so as not to fall off, as shown in Fig. 2. In this case, the hold bar 12 is locked by a bar fixing portion 14 formed on the rear end side, so that the hold bar 12 cannot rotate and can stably hold the tablet PC 3.

[0024] The terminal unit 31 of the tablet PC 3 is provided with, for example, a USB (Universal Serial Bus) terminal, and this USB terminal is used for communication with the main body unit 10. The main body 10 is provided with an openable / closable cover 16, and opening the cover 16 enables a cable connection to the terminal unit 31 of the tablet PC 3. For example, a USB cable from inside the main body 10 is disposed inside the cover 16, and with the tablet PC 3 attached, the USB cable is connected to the USB terminal of the terminal unit 31. This brings the controller 1 and the tablet PC 3 into a connected state that enables data transmission.

[0025] A handle 11 is provided at the front end of the main body 10, and a user can carry the control device 1 by using the handle 11. In addition, strap holders 20 are provided on the left and right front ends and the left and right rear ends of the main body 10, and by attaching straps to these, the user can position the control device 1 stably in front of their body.

[0026] The main body 10 is provided with various controls that can be operated by the user. As shown in Figs. 3 and 4, six operation switches 17 are provided on the left and right sides of the top surface of the main body 10. The operation switches 17 are, for example, three-position alternate switches. The user can assign any operation function to each operation switch 17. For example, a shutter operation or zoom operation for the camera 82 may be assigned, or an operation related to piloting the drone 2 may be assigned.

[0027] In addition, for example, three joysticks 18 are provided on the top surface of the main body 10. The joysticks 18 are operable as sticks and also function as push switches that can be pressed in. For example, the joystick 18 on the front right side of the top surface is used as an operator for operating the gimbal of the camera 82, and the other pair of left and right joysticks 18 are used as operators for piloting the drone 2.

[0028] In addition, a power switch 19 is provided on the top surface of the main body 10. As shown in FIG. 5, switches 27 are provided on the left and right sides of the bottom surface of the main body 10.

[0029] 7 and 8, a charging port 26 is provided on the left side surface of the main body 10. By connecting an external charging device (such as a power adapter) to the terminal inside this charging port 26, it becomes possible to operate using an external power source and charge the internal battery.

[0030] The main body 10 is provided with a plurality of antennas. As shown in FIG. 5, dipole antennas 21, 22, and 23 are provided on the lower surface side of the main body 10, and patch antennas 24 and 25 are also provided. The dipole antennas 21, 22, and 23 are rotatable about shafts 21a, 22a, and 23a, respectively. The patch antennas 24 and 25 are also rotatable about shafts 24a and 25a, respectively.

[0031] FIG. 5 shows a state in which the antennas (21 to 25) are stored on the underside of the main body 10. FIG. 6 shows a state in which each of the antennas (21 to 25) is rotated approximately 90 degrees from the stored state. FIG. 7 shows a state in which each of the antennas (21...25) is rotated by 90 degrees or more from the stored state. FIG. 8 shows the state of FIG. 6 from the side of the main body 10. In FIG.

[0032] The dipole antennas 21, 22, and 23 and the patch antennas 24 and 25 can be manually rotated as desired, allowing the user to adjust the reception conditions of image signals and telemetry data by moving each antenna. During system operation, the user deploys each antenna (21...25) as shown in Fig. 6 or Fig. 7 and uses the control device 1.

[0033] The angle of each antenna (21...25) can be adjusted to adjust the direction of strong radio waves. For example, the dashed arrow in Figure 6 shows an example of the direction of strong radio waves (direction of the receiving surface). For example, by adjusting the antenna angle so that this receiving surface direction is facing the direction of drone 2, it is possible to maintain good communication conditions and perform communication.

[0034] <3. Transmission and reception configuration> The internal configuration of the drone 2 and the control device 1 will be described with reference to FIG. The drone 2 is equipped with an aerial station 80, a camera 82, a flight controller 83, and antennas 84 and 85.

[0035] The aerial station 80 communicates with the pilot device 1 and processes information transmission to a camera 82 and a flight controller 83 based on the communication. The flight controller 83 controls the flight of the drone 2 and performs sensing using various sensors. The camera 82 captures an image and outputs an image signal SV0. The camera 82 is provided with a gimbal mechanism (not shown).

[0036] The antenna 84 is a first communication antenna used for the first wireless communication, which is a one-way communication in the 5.7 GHz band. The antenna 85 is a second communication antenna used for a second wireless communication, which is simplex communication in the sub-GHz band.

[0037] The aerial station 80 supplies the control signal CM transmitted from the controller 1 by the second wireless communication to the camera 82 (or gimbal mechanism). This causes the camera operation or gimbal operation to be performed in response to the user's operation on the controller 1 side. The aerial station 80 also supplies the control signal CM and the request signal transmitted from the control device 1 through the second wireless communication to the flight controller 83. This allows the drone 2 to fly in response to the operation of the user on the control device 1 side, and transmits the telemetry data TM in response to the request signal.

[0038] The aerial station 80 also performs processing to transmit an image signal SV0 captured by a camera 82 from an antenna 84 via a first wireless communication. The aerial station 80 also performs a process of transmitting the telemetry data TM input from the flight controller 83 from the antenna 85 via a second wireless communication.

[0039] The control device 1 includes a ground station 50, a memory unit 70, an operation unit 75, and the dipole antennas 21, 22, and 23, and patch antennas 24 and 25 described above.

[0040] In the pilot control device 1, of the three dipole antennas 21, 22, and 23, the dipole antenna 23 at the center of the underside of the main body 10 is used as a second communication antenna used for the second wireless communication. In addition, the dipole antennas 21, 22 and the patch antennas 24, 25 are used as a first communication antenna used for the first wireless communication.

[0041] The memory unit 70 has the memory card 5 shown in FIG.

[0042] The operation unit 75 is made up of operators such as the operation switch 17, the joystick 18, the power switch 19, and the switch 27, and operation detection circuits for these.

[0043] The ground station 50 receives image signals using a first communication antenna (dipole antennas 21, 22 and patch antennas 24, 25) and receives telemetry data TM using a second communication antenna (dipole antenna 23), and transmits control signals CM and request signals.

[0044] The ground station 50 can transmit the received image signal SV1 to the tablet PC 3 via the terminal 71. The ground station 50 can also transmit the received telemetry data TM to the tablet PC 3 via the terminal 72 . As a result, on the tablet PC 3 side, an application program corresponding to the pilot device 1 is started, so that the input image signal SV1 and telemetry data TM can be processed and displayed on the display screen 30. Therefore, the user can pilot the drone 2 and operate the camera while viewing the images captured by the drone 2 and the telemetry data on the display screen 30.

[0045] Moreover, the ground station 50 can supply the received image signal SV2 to the storage unit 70 so that it can be stored in the memory card 5. Furthermore, the ground station 50 can supply the received image signal SV3 to a terminal 73. When the monitor device 4 is connected to the terminal 73, the image captured by the drone 2 is displayed on the monitor device 4.

[0046] A detailed configuration of the ground station 50 is shown in FIG. The earth station 50 is provided with receiving circuits 51, 52, 54, and 55 corresponding to the dipole antennas 21, 22 and patch antennas 24, 25, respectively, and performs radio wave receiving processing corresponding to each antenna.

[0047] The reception outputs of the receiving circuits 51, 54 of the dipole antenna 21 and the patch antenna 24 are input to a radio wave selection section 56, and the one with the better reception condition is selected.

[0048] The reception outputs of the receiving circuits 52, 55 of the dipole antenna 22 and the patch antenna 25 are input to a radio wave selection section 57, and the one with the better reception condition is selected.

[0049] The signals selected by the radio wave selection units 56 and 57 are supplied to an image synthesis unit 58 using an FPGA (field-programmable gate array) for image synthesis. For example, synthesis is performed for each frame of the image signal, for example, in pixel block units or line units, such that the signal with the fewest errors or missing pixels is selected.

[0050] The image signal for each frame synthesized by the image synthesis unit 58 is subjected to necessary processing such as adding an on-screen display (OSD) and changing the resolution by the image setting unit 59, and is output as image signals SV1, SV2, and SV3. For example, the image signal SV1 is supplied to the tablet PC 3 from a terminal 71.

[0051] A CPU (Central Processing Unit) 60 controls the synthesis process of the image synthesis unit 58 and the OSD process of the image setting unit 59 in relation to the above-mentioned image signal reception.

[0052] A transmission / reception circuit 53 and a modulation / demodulation unit 61 are provided for the dipole antenna 23. For example, when transmitting a control signal or a request signal in response to an operation of the operation unit 75, the CPU 60 supplies data such as these control signals to the modulation / demodulation unit 61. This data such as the control signal is modulated by the modulation / demodulation unit 61 and transmitted from the dipole antenna 23 via the transmission / reception circuit 53.

[0053] Moreover, the radio waves received by the dipole antenna 23 are detected by the transmission / reception circuit 53 and demodulated by the modulation / demodulation unit 61. As a result, the telemetry data TM from the drone 2 is received and transmitted to the tablet PC 3 via the terminal 72. The above-mentioned receiving process of the telemetry data TM and the above-mentioned receiving process of the image signal are performed asynchronously.

[0054] 4. Effects of the embodiment and modifications According to the communication system of the above embodiment, the following effects can be obtained. The communication system of the embodiment is a communication system between a drone 2, which is an unmanned mobile body, and a control device 1. This communication system simultaneously executes a first wireless communication in which an image signal captured by a camera 82 attached to the drone 2 is transmitted to the control device 1 by one-way communication in a first frequency band, and a second wireless communication in which a control signal is transmitted from the control device 1 to the drone 2 and telemetry data is transmitted from the drone 2 to the control device 1 by one-way communication in a second frequency band. In such a communication system, image signals, which have a large data size, can be separated from telemetry data and control signals, thereby stabilizing the transmission of both. In addition, image signals are transmitted in a high-frequency band, which is advantageous in terms of transfer rate, and image transmission can be stabilized. In particular, the first wireless communication is one-way, which allows the control device 1 to increase the reception gain and improve the reception sensitivity of image signals from long distances, resulting in excellent stable image display.

[0055] Specifically, using the 5.7 GHz band for the first wireless communication is suitable for transmitting and receiving a large amount of data for images because it provides a sufficient bandwidth. Communication of control signals and telemetry data uses the sub-GHz band because the amount of data is small but long-distance compatibility and good communication performance are required. By using each of these frequency bands, it is possible to optimally realize image transmission, telemetry data transmission, and control functions.

[0056] In particular, when flying the drone 2 up to a distance of, for example, about 5 km, the user will operate the drone 2 while looking at the captured images. For this reason, stability of image communication over long distances is extremely desirable in the communication system between the aircraft and the control device.

[0057] The control device 1 of the embodiment includes a ground station 50 that simultaneously processes the first wireless communication and the second wireless communication, a first communication antenna (21, 22, 24, 25) used to receive the first wireless communication, and a second communication antenna (23) used to transmit and receive the second wireless communication. In this way, the control device 1 is configured to correspond to the communication method of the embodiment in which the first and second wireless communications are simultaneously performed. In particular, by making the first communication antenna dedicated to reception, the reception gain can be set high, which is also suitable for long-distance image transmission.

[0058] The control device 1 of the embodiment has an arrangement space 15 as a mounting section for mounting a tablet PC 3, which is a separate information processing device equipped with a monitor screen, and is configured to asynchronously transmit image signals received via the first wireless communication and telemetry data received via the second wireless communication to the tablet PC 3. This allows the tablet PC 3, which serves as a separate information processing device, to display images captured by the drone 2 and telemetry data. In particular, by performing display processing of images and telemetry data by software processing on the information processing device side, the control device 1 side can simply transmit the image signal and telemetry data to the tablet PC 3 upon reception without any particular synchronization processing. This simplifies the configuration of the ground station 50 while realizing appropriate presentation of the image signal and telemetry data to the user.

[0059] Furthermore, by using the tablet PC 3, the user can control the drone 2 while viewing images from the drone 2, providing the user with an extremely suitable control device for flying the drone 2 far away where it is out of sight. Another advantage is that by transmitting the image signal and the telemetry data to the tablet PC 3 independently of each other, the other can be displayed on the tablet PC 3 even if reception of one is interrupted.

[0060] Although the image signal and the telemetry data are asynchronous, the received data is transmitted to the tablet PC 3 as is, so that the displayed contents on the tablet PC 3 are synchronized to a certain degree. Therefore, the user can view telemetry data and captured images that are almost the same time. Furthermore, even if the data rates of the image signal and the telemetry data are different, it is possible to display information at the same time to a certain extent without forcing synchronization.

[0061] In the embodiment, the control device 1 is exemplified as a first communication antenna including a plurality of antennas including patch antennas 24 and 25. In order to support image transmission from long distances, for example, patch antennas 24, 25 and dipole antennas 21, 22 are provided as first communication antennas. The patch antennas 24, 25 have a relatively narrow directivity and high gain, making it possible to support long-distance communication. Image reception performance can also be improved by performing diversity reception using multiple antennas.

[0062] In the embodiment, the control device 1 is exemplified as a first communication antenna including a plurality of antennas including patch antennas 24, 25 and dipole antennas 21, 22. The patch antennas 24 and 25 can support image transmission from long distances, and the dipole antennas 21 and 22 can also support the case where the drone 2 is flying at a close distance and image signals need to be received with wide directivity. This makes it possible to realize appropriate image reception regardless of the position of the drone 2. In the embodiment, the patch antennas 24 and 25 and the dipole antennas 21 and 22 are used as the first communication antennas, but the antenna configuration is not limited to this. Other types of antennas may be used, and the number of antennas may be increased or decreased.

[0063] In the embodiment, the first communication antenna of the control device 1 includes patch antennas 24, 25 whose receiving surface directions are movable. By making the receiving surface direction of the relatively narrow-directivity patch antennas 24, 25 movable, the user can adjust the receiving condition. Specifically, the user can manually adjust the image to obtain the best image quality while viewing the captured image on the tablet PC 3, which makes the adjustment easy and makes it easy to obtain good image quality for the captured image. In other words, because the system is one in which the drone 2 is operated while viewing the captured image at hand, the user can easily adjust the receiving condition by adjusting the patch antennas 24, 25.

[0064] In addition, the first communication antenna is movable from a stored state on the underside of the main body so that the receiving surface faces forward. The patch antennas 24, 25 and the dipole antennas 21, 22, 23 can be stored on the underside of the main body 10. This makes it possible to prevent the antennas from getting in the way when the control device 1 is carried or stored. Furthermore, when in use, patch antennas 24, 25 can be oriented forward. In this case, the user can move patch antennas 24, 25 on the lower surface while holding controller 1 in front of the body, for example, with a strap, which provides good usability.

[0065] In the above, a drone is used as an example of an unmanned mobile body; however, in the present invention, unmanned mobile bodies are not limited to unmanned aerial vehicles such as drones, and may take forms other than aerial vehicles, such as unmanned ground vehicles, unmanned surface ships, unmanned surface boats, and unmanned submarine boats. [Explanation of symbols]

[0066] 1. Controls 2. Drone 3. Tablet PC 10 Main body 21, 22, 23 Dipole antenna 24,25 Patch antenna 50 Ground Station 51, 52, 54, 55 Receiver circuit 53 Transmitting and receiving circuit 56,57 Radio wave selection unit 58 Image synthesis unit 59 Image Settings 60 CPU 61 Modulation and demodulation section 80 Aerial station 82 Camera 83 Flight Controller 84,85 Antenna

Claims

1. A communication system between an unmanned vehicle and a control device, comprising: A first wireless communication that transmits an image signal captured by a camera attached to the unmanned moving body to the control device by one-way communication in a first frequency band; A second wireless communication in which the control signal is transmitted from the control device to the unmanned vehicle and the telemetry data is transmitted from the unmanned vehicle to the control device by simplex communication in a second frequency band lower than the first frequency band; A communication system that simultaneously

2. a ground station which simultaneously executes a first wireless communication, which is a one-way communication in a first frequency band, and a second wireless communication, which is a simplex communication in a second frequency band lower than the first frequency band, with an unmanned mobile body, receives an image signal captured by a camera attached to the unmanned mobile body through the first wireless communication, and transmits a control signal to the unmanned mobile body and receives telemetry data from the unmanned mobile body through the second wireless communication; a first communication antenna used for receiving the first wireless communication; a second communication antenna used for transmitting and receiving the second wireless communication; Control device.

3. a mounting section for mounting a separate information processing device having a monitor screen; The image signal received through the first wireless communication and the telemetry data received through the second wireless communication are asynchronously transmitted to the information processing device. The control device according to claim 2.

4. The first communication antenna is a plurality of antennas including a patch antenna. A control device according to claim 2 or 3.

5. The first communication antenna is a plurality of antennas including a patch antenna and a dipole antenna. A control device according to claim 2 or 3.

6. The first communication antenna includes a patch antenna whose receiving surface direction is movable. A control device according to claim 2 or 3.

7. The first communication antenna is movable from a state in which it is stored on the underside of the main body so that the receiving surface faces forward. A control device according to claim 6.

Images