Communication system and communication method for work vehicle and unmanned aircraft

Abstract

This communication system is mounted on either one of a work vehicle and an unmanned aircraft that flies around the work vehicle. The communication system comprises: a communication device which performs communication with the other of the work vehicle and the unmanned aircraft; and a control device which controls communications performed by the communication device and which changes the mode of communication between the work vehicle and the unmanned aircraft in accordance with the distance between the work vehicle and the unmanned aircraft.

Description

Communication system and communication method for work vehicle and unmanned aerial vehicle

[0001] The present disclosure relates to communication systems and methods for work vehicles and unmanned aerial vehicles.

[0002] An unmanned aerial vehicle (UAV) is an aircraft that cannot carry a person due to its structure and can fly by remote control or automatic pilot. Rotary-wing unmanned aerial vehicles are unmanned aerial vehicles that obtain lift using propellers that rotate around an axis, i.e., rotors. Small unmanned aerial vehicles equipped with multiple rotors (multi-rotor UAVs) are also called "drones," "multirotors," or "multicopters," and are widely used for applications such as aerial photography, surveying, logistics, and pesticide spraying.

[0003] Patent Literature 1 describes an unmanned aerial vehicle (unmanned aerial vehicle) that changes its flight position in conjunction with the operation of agricultural machinery. For example, it describes an agricultural tractor transmitting information (such as the position of the field, the position of the tractor, vehicle speed, and the raised / lowered state of the lifting device connecting the work implement) to the unmanned aerial vehicle, which then changes its flight position based on that information. It also describes the unmanned aerial vehicle transmitting information such as the size and position of an object detected by a sensing device to the tractor, which then changes the detection area for detecting obstacles based on that information.

[0004] Japanese Patent Application Laid-Open No. 2022-104737

[0005] The present disclosure provides a communication system and a communication method for realizing cooperation between a work vehicle that performs ground work such as agricultural work or construction work and an unmanned aerial vehicle.

[0006] In an exemplary and non-limiting embodiment, the communication system of the present disclosure is mounted on one of a work vehicle and an unmanned aerial vehicle flying around the work vehicle. The communication system includes a communication device that communicates with the other of the work vehicle and the unmanned aerial vehicle, and a control device that controls communication by the communication device and changes a communication mode between the work vehicle and the unmanned aerial vehicle depending on the distance between the work vehicle and the unmanned aerial vehicle.

[0007] According to an embodiment of the present disclosure, the communication mode (e.g., communication volume, type of data to be transmitted, communication method, etc.) can be changed depending on the distance between the work vehicle and the unmanned aerial vehicle, thereby making it possible to more appropriately carry out the communication required for linking the work vehicle and the unmanned aerial vehicle.

[0008] 1 is a block diagram showing schematically some examples of a rotary drive unit that rotates rotors in an unmanned aerial vehicle having multiple rotors. FIG. 2 is a plan view showing typically one basic configuration example of an unmanned aerial vehicle having multiple rotors. FIG. 3 is a side view showing typically one basic configuration example of an unmanned aerial vehicle having multiple rotors. FIG. 4 is a plan view showing typically another basic configuration example of an unmanned aerial vehicle having multiple rotors. FIG. 5 is a block diagram showing a basic configuration example of a battery-powered multicopter. FIG. 6 is a block diagram showing a basic configuration example of a series hybrid drive multicopter. FIG. 7 is a block diagram showing a basic configuration example of a parallel hybrid drive multicopter. FIG. 8 is a diagram showing an example of a system including a multicopter and an agricultural work vehicle. FIG. 9 is a block diagram showing an example configuration of the system shown in FIG. 3. FIG. 10 is a flowchart showing an example of a communication method executed by a control device of a work vehicle or a multicopter. FIG. 11 is a first diagram for explaining an example of a communication method in a system in which a work vehicle and a multicopter operate in conjunction with each other. FIG. 12 is a second diagram for explaining an example of a communication method in a system in which a work vehicle and a multicopter operate in conjunction with each other. FIG. 13 is a flowchart showing an example in which the communication mode changes between three stages depending on the distance between the work vehicle and the multicopter. It is a block diagram showing an example of the hardware configuration of a control device for a work vehicle.It is a flowchart showing an example of a display method executed by a processor (processing device) in the control device for a work vehicle.It is a diagram showing an example of a map image displayed on a display device.

[0009] An unmanned aerial vehicle with multiple rotors includes a rotary drive unit that rotates the rotors (hereinafter sometimes referred to as "propellers"). Hereinafter, such an unmanned aerial vehicle will be referred to as a "multicopters."

[0010] There are various configurations of the rotary drive device provided in a multicopter. Fig. 1A is a block diagram schematically illustrating four examples of the rotary drive device 3 in the present disclosure.

[0011] The first rotation drive device 3A shown in FIG. 1A has a plurality of electric motors (hereinafter referred to as "motors") 14 that rotate a plurality of rotors 2, and a battery 52 that stores power to be supplied to each motor 14. The battery 52 is, for example, a secondary battery such as a polymer lithium-ion battery. Each rotor 2 is connected to the output shaft of the corresponding motor 14 and rotated by the motor 14. In order to increase the payload and / or flight time, it is necessary to increase the power storage capacity of the battery 52. ​​The power storage capacity of the battery 52 can be increased by increasing the size of the battery 52, but increasing the size of the battery 52 results in an increase in weight.

[0012] The second rotation drive device 3B shown in FIG. 1A includes a power transmission system 23 mechanically connected to the rotor 2 and an internal combustion engine 7a that provides driving force (torque) to the power transmission system 23. The power transmission system 23 includes mechanical components such as gears or belts, and transmits torque from the output shaft of the internal combustion engine 7a to the rotor 2. The internal combustion engine 7a can efficiently generate mechanical energy by burning fuel. Examples of the internal combustion engine 7a include a gasoline engine, a diesel engine, and a hydrogen engine. The number of internal combustion engines 7a included in the rotation drive device 3B is not limited to one.

[0013] The third rotary drive device 3C shown in FIG. 1A includes multiple motors 14, a power buffer 9 that stores power to be supplied to each motor 14, a power generator 8 such as an alternator that generates power, and an internal combustion engine 7a that provides mechanical energy for the power generator 8 to generate electricity. A typical example of the power buffer 9 is a battery such as a secondary battery, but it may also be a capacitor. In the third rotary drive device 3C, even if the power buffer 9 does not have a large storage capacity, the power generator 8 generates power using the driving force (mechanical energy) of the internal combustion engine 7a, thereby enabling an increase in payload and / or flight time. This type of drive is called a "series hybrid drive." The power generator 8 and internal combustion engine 7a in the series hybrid drive are called a "range extender" because they extend the flight distance of the multicopter.

[0014] 1A includes a plurality of motors 14, a power buffer 9 that stores power to be supplied to each motor 14, a power generator 8 such as an alternator that generates power, an internal combustion engine 7a that provides driving force for generating power to the power generator 8, and a power transmission system 23 that transmits the driving force generated by the internal combustion engine 7a to a rotor 2 to rotate the rotor 2. At least one rotor 2 of the plurality of rotors 2 is rotated by the internal combustion engine 7a, and the other rotors 2 are rotated by the motor 14. In the fourth rotary drive device 3D, the mechanical energy generated by the internal combustion engine 7a can also be used to rotate the rotor 2 without being converted into electric power, thereby improving energy utilization efficiency. This type of drive is called a "parallel hybrid drive."

[0015] Fig. 1B is a plan view schematically illustrating one basic configuration example of multicopter 10. The configuration example of Fig. 1B includes the first rotational drive device 3A shown in Fig. 1A as the rotational drive device 3. That is, the rotational drive device 3 (3A) in this example includes a motor 14 and a battery 52. ​​Fig. 1C is a side view schematically illustrating multicopter 10.

[0016] 1B and 1C includes a plurality of rotors 2, an airframe 4, and an airframe frame 5 that supports the rotors 2 and the airframe 4. The airframe frame 5 supports the airframe 4 at its center and rotatably supports the plurality of rotors 2 with a plurality of arms 5A extending outward from the center. A motor 14 that rotates the rotors 2 is provided near the tip of each arm 5A. The airframe 4 and the airframe frame 5 are sometimes collectively referred to as the "airframe 11."

[0017] 1B, the multicopter 10 is a quad-type multicopter (quadcopter) having four rotors 2. The rotors 2 located on one diagonal line rotate in the same direction (clockwise or counterclockwise), while the rotors 2 located on different diagonal lines rotate in opposite directions.

[0018] The main body 4 includes a control device 4a that controls the operation of devices and components mounted on the multicopter 10, a group of sensors 4b connected to the control device 4a, a communication device 4c connected to the control device 4a, and a battery 52.

[0019] The control device 4 a may include, for example, a flight control device such as a flight controller and a host computer (companion computer). The companion computer can perform advanced arithmetic processing such as image processing, obstacle detection, and obstacle avoidance based on the sensor data acquired by the sensor group 4 b.

[0020] The sensor group 4b may include an acceleration sensor, an angular velocity sensor, a geomagnetic sensor, a barometric pressure sensor, an altitude sensor, a temperature sensor, a flow rate sensor, an imaging device, a laser sensor, an ultrasonic sensor, an obstacle contact sensor, and a Global Navigation Satellite System (GNSS) receiver. The acceleration sensor and the angular velocity sensor may be mounted on the airframe main body 4 as components of an IMU (Inertial Measurement Unit). Examples of the laser sensor may include, for example, a laser range finder used to measure the distance to the ground, and a two-dimensional or three-dimensional light detection and ranging (LiDAR).

[0021] The communication device 4c may include a wireless communication module for transmitting and receiving signals via an antenna to a transmitter or ground station (Ground Control Station (GCS)) on the ground, a mobile communication module using a cellular communication network, etc. The communication device 4c may receive signals such as control commands transmitted from the ground and transmit sensor data such as image data acquired by the sensor group 4b as telemetry information. The communication device 4c may have a function for communicating between multicopters and a satellite communication function. The control device 4a can be connected to a computer on the cloud via the communication device 4c. Some or all of the functions of the companion computer may be performed by the computer on the cloud.

[0022] The battery 52 is a secondary battery that stores power by charging and supplies power to the motors 14 by discharging. The battery 52 and the multiple motors 14 operate to rotate the multiple rotors 2, making it possible to generate a desired thrust.

[0023] Each of the multiple rotors 2 generally has multiple blades with a fixed pitch angle and generates thrust by rotation. The pitch angle may be variable. The multiple rotors 2 do not all need to have the same diameter (propeller diameter); one or more rotors 2 may have a larger diameter than the other rotors 2. The thrust (static thrust) generated by a rotating rotor 2 is generally proportional to the cube of the rotor 2 diameter. Therefore, when rotors 2 with different diameters are included, the rotor 2 with a relatively larger diameter may be referred to as the "main rotor," and the rotor 2 with a relatively smaller diameter may be referred to as the "sub-rotor." Note that, regardless of the diameter, the configuration of the rotary drive device 3 may include a rotor 2 capable of generating a relatively larger thrust and a rotor 2 with a relatively smaller thrust. In this case, the rotor 2 capable of generating a relatively larger thrust may be referred to as the "main rotor," and the rotor 2 with a relatively smaller thrust may be referred to as the "sub-rotor." For example, the rotor 2 that generates a relatively large thrust per rotation may be referred to as the "main rotor," and the rotor 2 that generates a relatively small thrust per rotation may be referred to as the "sub-rotor." In one example, the main rotor may be positioned more inward than the sub-rotors. In other words, each rotor 2 may be positioned so that the distance from the center of the airframe to the rotation axis of each main rotor is shorter than the distance from the center of the airframe to the rotation axis of each sub-rotor.

[0024] In this example, the rotary drive device 3 includes a plurality of motors 14. As mentioned above, the rotary drive device 3 may include an internal combustion engine 7a.

[0025] FIG. 1D is a plan view schematically illustrating an example of the basic configuration of a multicopter 10 including a second rotational drive device 3B as the rotational drive device 3. In the example shown in FIG. 1D , an internal combustion engine 7a is supported by the airframe main body 4. In this example, the driving force generated by the internal combustion engine 7a is transmitted to multiple rotors 2 via multiple power transmission systems 23, causing each rotor 2 to rotate. The control device 4a can change the rotational speed of each rotor 2 by controlling each power transmission system 23. The rotational drive device 3B may include a mechanism for changing the pitch angle of each blade of the multiple rotors 2. In this case, the control device 4a may adjust the lift generated by each rotor 2 by controlling the mechanism to change the pitch angle of the blades.

[0026] In a "parallel hybrid drive" in which some of the multiple rotors 2 are rotated by the internal combustion engine 7a and the other rotors 2 are rotated by the motor 14, the internal combustion engine 7a and the battery 52 are supported on the aircraft body 4. At least one rotor 2 of the multiple rotors 2 is connected to the internal combustion engine 7a via the power transmission system 23, and the other rotors 2 are connected to the motor 14.

[0027] In such a parallel hybrid drive, the diameter of one or more rotors 2 rotated by the internal combustion engine 7a may be larger than the diameter of the other rotors 2 rotated by the motor 14. In other words, the internal combustion engine 7a may be used to rotate the main rotor, and the motor 14 may be used to rotate the sub-rotor. In such a case, the main rotor is primarily used to generate thrust, and the sub-rotor is used to generate thrust and for attitude control. The main rotor may also be called a "booster rotor," and the sub-rotor may also be called an "attitude control rotor."

[0028] In the case of a parallel hybrid drive, the internal combustion engine is used for both thrust generation and power generation. By selectively transmitting the driving force (torque) generated by the internal combustion engine to one or both of the rotor and the power generator, it is possible to achieve a good balance between thrust generation and power generation.

[0029] Equipping a multicopter with an internal combustion engine and using it to generate thrust and / or electricity contributes to increased payload and flight time. It is desirable to control the attitude of a multicopter by rotating the propellers with a motor, which has better response characteristics than an internal combustion engine. Therefore, in applications requiring precise control of the multicopter's attitude, it is desirable to employ a parallel hybrid drive or series hybrid drive to increase the payload and flight time. If the rotary drive device 3 is equipped with a mechanism for changing the pitch angle of each blade of the multiple rotors 2, the attitude can also be adjusted by changing the pitch angle of each blade.

[0030] Increased payload and flight time may further expand the applications of multicopters. For example, in the agricultural field, multicopters are currently being used for spraying pesticides or monitoring crop growth conditions. However, by connecting various ground implements (hereinafter, sometimes simply referred to as "implements") to a multicopter, various agricultural tasks can be performed from the air. Agricultural implements are sometimes called "implements." Examples of implements include sprayers that spray pesticides on crops, mowers, seeders, spreaders, rakes, balers, harvesters, plows, harrows, or rotary tillers. Work vehicles such as tractors are not included in the "implements" of this disclosure.

[0031] In the example shown in FIG. 1C , a work implement 200 is coupled to the multicopter 10. The work implement 200 can spray, for example, pesticides or fertilizers on a field or crops within the field. Increasing the payload and flight time allows for a larger and / or more versatile work implement 200. For example, by changing the work implement 200 coupled to the multicopter 10, a variety of ground tasks (agricultural operations) can be performed, including liquid and granular application of pesticides, fertilization, thinning, weeding, transplanting, direct seeding, and harvesting. The work implement 200 may be equipped with a mechanism such as a robotic hand. In this case, a single work implement 200 can perform a variety of ground tasks. If the work implement 200 has a sufficient space to accommodate materials, the work implement 200 can also be used to transport agricultural materials or harvested products over a wide area. The work implement 200 can be coupled to the multicopter 10 in a variety of ways. The multicopter 10 may suspend and tow the work machine 200 by a cable. The work machine 200 towed by the multicopter 10 can also perform ground work while being towed while the multicopter 10 is flying or hovering. The work machine 200 during work may be in the air or on the ground.

[0032] 1C , the multicopter 10 includes a power supply device 76. The power supply device 76 is a device that supplies power to the work machine 200 from a drive energy source, such as the battery 52 or the power generation device 8, included in the multicopter 10. Various functions of the work machine 200 can be performed using this power. The work machine 200 includes actuators such as motors that operate using power obtained from the power supply device 76 of the multicopter 10. The work machine 200 preferably includes a battery that stores power. The ESC 16 may be included in the control device 4a.

[0033] FIG. 2A is a block diagram showing an example of the basic configuration of a battery-powered multicopter 10. The battery-powered multicopter 10 includes multiple rotors 12, multiple motors 14 that rotate the rotors 12, multiple ESCs (electric speed controllers) 16 each having a motor drive circuit that drives the motors 14, a battery 52 that supplies power to the corresponding motors 14 via each ESC 16, a control device 4a that controls the multiple ESCs 16 to control attitude and perform flight, a sensor group 4b, a communication device 4c, and a power supply device 76 electrically connected to the battery 52. ​​For simplicity, FIG. 2A shows the rotors 12, motors 14, and ESCs 16 as a single block, but the number of rotors 12, motors 14, and ESCs 16 is actually multiple. This also applies to FIGS. 2B and 2C.

[0034] The control device 4a can receive control commands wirelessly, for example, from a ground station 6 located on the ground via the communication device 4c. The number of ground stations 6 is not limited to one and may be distributed across multiple locations. The communication device 4c can also receive control commands wirelessly from a control device operated by a pilot on the ground. The control device 4a may have the function of automatically or autonomously performing takeoff, flight, obstacle avoidance, and landing operations based on sensor data obtained from the sensor group 4b. The control device 4a may be configured to communicate with the work machine 200 connected to the power supply device 76 and acquire a signal indicating the status of the work machine 200 from the work machine 200. The control device 4a may also provide the work machine 200 with a signal that controls the operation of the work machine 200. Furthermore, the work machine 200 may generate a signal instructing the operation of the multicopter 10 and transmit it to the control device 4a. Such communication between the control device 4a and the work machine 200 can be performed via wired or wireless communication.

[0035] FIG. 2B is a block diagram showing an example of the basic configuration of a series hybrid drive multicopter 10. Similar to the battery-powered multicopter 10, the series hybrid drive multicopter 10 includes multiple rotors 12, multiple motors 14, multiple ESCs 16, a control device 4a, a sensor group 4b, and a communication device 4c. The illustrated series hybrid drive multicopter 10 further includes an internal combustion engine 7a, a fuel tank 7b for storing fuel for the internal combustion engine 7a, a power generation device 8 driven by the internal combustion engine 7a to generate electric power, a power buffer 9 for temporarily storing the electric power generated by the power generation device 8, and a power supply device 76 electrically connected to the power buffer 9. The power buffer 9 is, for example, a battery such as a secondary battery. The electric power generated by the power generation device 8 is supplied to the motor 14 via the power buffer 9 and the ESC 16. The electric power generated by the power generation device 8 may also be supplied to the work machine 200 via the power supply device 76.

[0036] FIG. 2C is a block diagram showing an example of the basic configuration of a parallel hybrid drive multicopter 10. Similar to the series hybrid drive multicopter 10, the parallel hybrid drive multicopter 10 includes multiple rotors 12, multiple motors 14 that respectively drive the multiple rotors 12, multiple ESCs 16, a control device 4a, a sensor group 4b, a communication device 4c, an internal combustion engine 7a, a fuel tank 7b, a power generator 8, a power buffer 9, and a power supply device 76. The parallel hybrid drive multicopter 10 further includes a drive train 27 that transmits the driving force of the internal combustion engine 7a, and a rotor 22 that rotates by receiving the driving force of the internal combustion engine 7a from the drive train 27. One of the rotor 12 and the rotor 22 may be referred to as the “first rotor” and the other as the “second rotor” to distinguish them from each other. The number of rotors 22 connected to the drive train 27 and rotating may be one or more.

[0037] In the parallel hybrid drive multicopter 10, the internal combustion engine 7a not only drives the power generation device 8 to generate electricity, but also mechanically transmits energy to the rotor 22 to rotate the rotor 22. On the other hand, in the series hybrid drive multicopter 10, all of the rotors 12 are rotated by the electric power generated by the power generation device 8. For this reason, in the series hybrid drive multicopter 10, if the power generation device 8 is, for example, a fuel cell, the internal combustion engine 7a is not an essential component.

[0038] As described above, the multicopter 10 can have a variety of configurations. For example, the multicopter 10 can spray pesticides, fertilizers, or seeds in a field, or can suspend a ground work machine to perform tasks such as mowing. The multicopter 10 can also be used in conjunction with industrial machinery (e.g., agricultural machinery or construction machinery) that performs ground work to support the industrial machinery in performing the ground work. Examples of agricultural machinery include agricultural work vehicles such as tractors, combine harvesters, rice transplanters, and riding cultivators. Examples of construction machinery include construction and civil engineering work vehicles such as backhoes, wheel loaders, and carriers. Ground work involves work on the ground, and includes, for example, agricultural work such as plowing, sowing, pest control, fertilizing, planting crops, and harvesting, as well as construction and civil engineering work such as excavating the ground.

[0039] FIG. 3 is a diagram illustrating an example of a system including a multicopter 10 and an agricultural work vehicle 100. In this example, the work vehicle 100 is an agricultural tractor. The work vehicle 100 may be an agricultural machine other than a tractor, or may be a construction machine. FIG. 3 also illustrates a server 300 that communicates with the multicopter 10 and the work vehicle 100. The server 300 may be a cloud server computer installed in a data center, for example. The server 300 can communicate with the work vehicle 100 and the multicopter 10 via relay devices (e.g., multiple routers and switches in a network). Indirect communication via the server 300 and direct wireless communication are possible between the work vehicle 100 and the multicopter 10. Note that while FIG. 3 illustrates one work vehicle 100 and one multicopter 10, the number of each of the work vehicles 100 and the multicopter 10 may be two or more.

[0040] FIG. 4 is a block diagram showing an example configuration of the system shown in FIG. 3 . In the example shown in FIG. 4 , the multicopter 10, similar to the example shown in FIG. 2A , includes multiple rotors 12, multiple motors 14 that drive the rotors 12, a battery 52 that stores power, a control device 4a that controls flight of the multicopter 10, a communication device 4c, and a sensor group 4b. Note that the power supply device 76 and the work machine 200 shown in FIG. 2A are omitted from FIG. 4 . For simplicity, FIG. 4 shows the rotors 12, the motors 14, and the ESC 16 as a single block, but the number of rotors 12, the motors 14, and the ESC 16 is actually multiple. Furthermore, the multicopter 10 may include at least one second rotor 22 driven by an internal combustion engine 7a, as shown in FIG. 2B or 2C . In this case, either a “series hybrid” or a “parallel hybrid” drive system may be adopted.

[0041] FIG. 4 illustrates examples of the sensor group 4b, including a GNSS receiver 41, an IMU 42, an altitude sensor 43, an imaging device 44, and a LiDAR sensor 45. The GNSS receiver 41 and the IMU 42 function as positioning devices that measure the position and attitude (pose) of the multicopter 10. The altitude sensor 43 measures the altitude of the multicopter 10 and outputs a signal indicating the altitude. Altitude refers to the vertical distance between a reference plane (e.g., the ground surface) and the aircraft. The altitude sensor 46 may be implemented, for example, by a barometer, a ranging device that measures the distance from the aircraft to the ground, or a combination of these. The imaging device 44 captures images of the surroundings of the multicopter 10 to generate and output image data. The LiDAR sensor 45 is an example of a ranging device that measures the distance to objects surrounding the multicopter 10. The imaging device 44 and the LiDAR sensor 45 are external sensors that sense the environment around the multicopter 10 and output sensor data.

[0042] The control device 4a controls the flight, communication, and other operations of the multicopter 10. The communication device 4c is a communication module that communicates with external devices such as the work vehicle 100 and the server 300. The communication device 4c may be configured to perform wireless communication using, for example, Wi-Fi (Wireless Fidelity, registered trademark), BLE (Bluetooth Low Energy), LPWA (Low Power Wide Area), specified low-power radio, or a cellular communication network such as 4G or 5G. The communication device 4c can communicate with the communication device 110 in the work vehicle 100 directly or indirectly via the network 90 and the server 300.

[0043] 4 includes a communication device 110, a control device 120, a GNSS receiver 130, an IMU 140, an imaging device 150, and a LiDAR sensor 160. The functions of these devices are similar to the functions of the corresponding devices in the multicopter 10. The work vehicle 100 also includes a display device 170 and a drive unit 180 that includes an engine, a running device, and the like.

[0044] The communication device 110 can communicate with the communication device 4c of the multicopter 10 directly or indirectly via the network 90 and the server 300. The control device 120 controls the operation of the work vehicle 100. The GNSS receiver 130 and IMU 140 function as positioning devices that measure the position and orientation of the work vehicle 100. The imaging device 150 and LiDAR sensor 160 function as external sensors that sense the environment around the work vehicle 100 and output sensor data. The display device 170 displays a map of the area in which the work vehicle 100 travels, as well as position information and speed information of the work vehicle 100 and the multicopter 10. The display device 170 may be an operation terminal installed on the work vehicle 100, or a portable terminal used by the user of the work vehicle 100.

[0045] The server 300 includes a communication device 310 that communicates with the communication device 4c of the multicopter 10 and the communication device 110 of the work vehicle 100 via the network 90, and a processing device 320 that performs processing based on information obtained from the multicopter 10 and the work vehicle 100.

[0046] <Communication System> In the example shown in Figure 4, the multicopter 10 is equipped with a communication system including a communication device 4c and a control device 4a. Similarly, the work vehicle 100 is equipped with a communication system including a communication device 110 and a control device 120. These communication systems enable communication between the multicopter 10 and the work vehicle 100 to operate in conjunction with each other. Below, an example of the operation of the communication systems installed in each of the multicopter 10 and the work vehicle 100 will be described.

[0047] The control device 4a in the multicopter 10 controls communication by the communication device 4c. The control device 4a changes the mode of communication with the work vehicle 100 depending on the distance between the work vehicle 100 and the multicopter 10. Similarly, the control device 120 in the work vehicle 100 controls communication by the communication device 110. The control device 120 changes the mode of communication with the multicopter 10 depending on the distance between the work vehicle 100 and the multicopter 10.

[0048] A change in communication mode may include, for example, a change in the type of data to be transmitted, the frequency of communication, the amount of communication, or the communication method. For example, when the distance between the work vehicle 100 and the multicopter 10 is greater than a threshold (i.e., when the two are far apart), they may share their sensing information with each other. The sensing information may be acquired by an external sensor, such as the image capture device 44, 150 or the LiDAR sensor 45, 160. Conversely, when the distance between the work vehicle 100 and the multicopter 10 is equal to or less than the threshold (i.e., when the two are close), they may share information necessary for collision avoidance (e.g., position information, attitude information, and / or altitude information). The position information may be acquired by a positioning device, such as the GNSS receiver 41, 130. The attitude information may be acquired by an attitude detection sensor, such as the IMU 42, 140. The altitude information may be acquired by the altitude sensor 43. Alternatively, when the two are far apart, communication may be performed indirectly via an external computer, such as the server 300, and when the two are close, direct wireless communication may be performed.

[0049] The distance between the work vehicle 100 and the multicopter 10 can be calculated, for example, based on the respective position information output from positioning devices (e.g., GNSS receivers 130 and 41) mounted on each of the work vehicle 100 and the multicopter 10. That is, the control devices 120 and 4a can be configured to acquire the position information of the work vehicle 100 from the positioning device mounted on the work vehicle 100, acquire the position information of the multicopter 10 from the positioning device mounted on the multicopter 10, and calculate the distance between the work vehicle 100 and the multicopter 10 based on the position information. Alternatively, the control devices 120 and 4a may acquire information indicating the distance between the work vehicle 100 and the multicopter 10 from a ranging device (e.g., LiDAR sensor 160 or 45) mounted on the work vehicle 100 or the LiDAR sensor 45. In addition, the distance between the work vehicle 100 and the multicopter 10 may be measured using a beacon transmitter mounted on one of the work vehicle 100 and the multicopter 10 and a beacon receiver mounted on the other of the work vehicle 100 and the multicopter 10.

[0050] Below, several examples of methods for changing the communication mode depending on the distance between the work vehicle 100 and the multicopter 10 will be described. In the following description, unless otherwise specified, the subject of operation will be the control device 4a in the multicopter 10. Each example of the communication method described below can also be executed by the control device 120 in the work vehicle 100 in the same way. This allows information to be shared between the work vehicle 100 and the multicopter 10.

[0051] FIG. 5 is a flowchart showing an example of a communication method executed by the control device 4a.

[0052] In step S101, the control device 4a acquires, from the respective positioning devices, position information of the work vehicle 100 and the multicopter 10. The position information may include latitude and longitude information measured by the GNSS receiver 41, for example.

[0053] In step S102, the control device 4a calculates the distance between the work vehicle 100 and the multicopter 10 based on the respective acquired position information. The control device 4a can calculate the distance between the work vehicle 100 and the multicopter 10 from the difference between the positions of the work vehicle 100 and the multicopter 10.

[0054] Note that instead of the operations of steps S101 and S102, distance information between the work vehicle 100 and the multicopter 10 may be obtained using a distance measuring device or a beacon, as described above.

[0055] In step S103, the control device 4a compares the calculated distance with a threshold value. The threshold value is stored in advance in a storage device such as a memory of the control device 4a. The threshold value is a predetermined value, such as 5 m, 10 m, or 20 m, and is determined depending on the purpose or use of the system. If the distance is greater than the threshold value, the process proceeds to step S104. If the distance is equal to or less than the threshold value, the process proceeds to step S105.

[0056] In step S104, the control device 4a communicates with the work vehicle 100 in the first communication mode. In the first communication mode, the control device 4a may be configured to transmit position information acquired from a positioning device (e.g., the GNSS receiver 41) of the multicopter 10 to the work vehicle 100 via the communication device 4c. Alternatively, in the first communication mode, the control device 4a may transmit sensor data acquired from an external sensor (e.g., the imaging device 44 or the LiDAR sensor 45) mounted on the multicopter 10 to the work vehicle 100 via the communication device 4c. In the first communication mode, the control device 4a may transmit both position information and sensor data to the work vehicle 100. By transmitting the position information and / or sensor data to the work vehicle 100, the control device 120 of the work vehicle 100 can display information such as the position of the multicopter 10 or images acquired by sensing on the display device 170.

[0057] In step S105, the control device 4a communicates with the work vehicle 100 in a second communication mode different from the first communication mode. In the second communication mode, the control device 4a can be configured to transmit, to the work vehicle 100 via the communication device 4c, in addition to position information and / or sensor data, attitude information acquired from an attitude detection sensor (e.g., the IMU 42) mounted on the multicopter 10 and / or altitude information acquired from the altitude sensor 43. By transmitting at least one of the attitude information and altitude information to the work vehicle 100 in addition to the position information, the work vehicle 100 can more easily detect the multicopter 10 as an obstacle, making it easier to avoid a collision between the work vehicle 100 and the multicopter 10.

[0058] The communication in the first communication mode in step S104 and the communication in the second communication mode in step S105 may each be repeatedly performed at a predetermined time interval. In this case, the communication in the second communication mode may be performed at a shorter time interval than the communication in the first communication mode. Furthermore, in the communication in the first communication mode in step S104, the control device 4a may be configured to indirectly transmit data to the work vehicle 100 via a server 300, which is an external computer on the cloud, using a public line such as 4G or 5G. This is because, when the distance between the work vehicle 100 and the multicopter 10 is long, there is no risk of a collision between them, and therefore the speed and frequency of communication between them may be low. Conversely, in the communication in the second communication mode in step S105, the control device 4a may be configured to transmit data directly to the work vehicle 100 using wireless communication such as Wi-Fi (registered trademark), Bluetooth, or specified low-power radio. This is because when the distance between the work vehicle 100 and the multicopter 10 is short, it is desirable to increase the speed and frequency of communication between the two and exchange information such as position and attitude at short intervals in order to avoid collisions.

[0059] In step S106, the control device 4a determines whether to end the operation. For example, when a preprogrammed flight has ended, or when an operation end command has been received from an external device such as a pilot aircraft or a remote monitoring device, the control device 4a ends the operation. The control device 4a repeats the operations of steps S101 to S106 until it determines that the operation should be ended.

[0060] 5 can be similarly executed by the control device 120 of the work vehicle 100, as well as the control device 4a of the multicopter 10. That is, when the distance between the work vehicle 100 and the multicopter 10 is greater than a threshold, the control device 120 of the work vehicle 100 may transmit position information acquired from a positioning device (e.g., the GNSS receiver 130) mounted on the work vehicle 100 to the multicopter 10 via the communication device 110. When the distance is greater than the threshold, the control device 120 may also transmit sensor data acquired from an external sensor (e.g., the image capture device 150 or the LiDAR sensor 160) mounted on the work vehicle 100 to the multicopter 10 via the communication device 110. Conversely, when the distance is equal to or less than the threshold, the control device 120 may transmit, in addition to the position information, attitude information acquired from an attitude detection sensor (e.g., the IMU 140) mounted on the work vehicle 100 to the multicopter 10 via the communication device 4c. Furthermore, if the distance is greater than a threshold, the control device 120 may communicate with the multicopter 10 via the server 300, and if the distance is less than or equal to the threshold, the control device 120 may communicate directly with the multicopter 10.

[0061] Next, a more specific example of the communication method according to this embodiment will be described with reference to FIGS.

[0062] 6 and 7 show an example of a communication method in a system in which the work vehicle 100 and the multicopter 10 operate in conjunction with each other. Fig. 6 shows a state in which the distance between the work vehicle 100 and the multicopter 10 is greater than a threshold. Fig. 7 shows a state in which the distance between the work vehicle 100 and the multicopter 10 is equal to or less than the threshold.

[0063] In this example, work vehicle 100 travels along a predetermined travel route while performing agricultural work such as spreading fertilizer, chemicals, or seeds, planting crop seedlings, harvesting crops, or mowing in a field 70. Work vehicle 100 shown in FIG. 6 is a tractor that performs agricultural work by driving an implement coupled to work vehicle 100. Work vehicle 100 is not limited to tractors, and may be, for example, a transplanter such as a rice transplanter, or a harvester such as a combine. Furthermore, work vehicle 100 is not limited to agricultural machinery, and may also be construction machinery.

[0064] The travel route of the work vehicle 100 shown in Figure 6 meanders regularly, as indicated by the thick arrows in the figure. The work vehicle 100 may travel manually by a user, or may travel automatically. When the work vehicle 100 travels automatically, map information of the field 70 and information about the travel route are recorded in advance in a storage device of the work vehicle 100. The control device 120 can cause the work vehicle 100 to travel along a preset travel route based on the position information and attitude information of the work vehicle 100 output from a positioning device including the GNSS receiver 130, the IMU 140, etc.

[0065] The multicopter 10 flies around the work vehicle 100 and supports ground work by the work vehicle 100. For example, if the work vehicle 100 spreads fertilizer, chemicals, or seeds, or plants crop seedlings, the multicopter 10 can be configured to perform a transport operation to deliver agricultural materials to the work vehicle 100 when the remaining amount of fertilizer, chemicals, seeds, or seedlings (hereinafter, these may be referred to as "agricultural materials" or simply "materials") is low. Alternatively, if the work vehicle 100 is a harvester that harvests crops, the multicopter 10 can be configured to, for example, receive harvested products stored in a tank of the work vehicle 100 and transport them to a predetermined location.

[0066] In the system described above, the work vehicle 100 may be equipped with a sensor that measures the remaining amount of materials or the amount of harvested crops. The control device 120 may be configured to control the communication device 110 to send a request to call the multicopter 10 to the multicopter 10 based on a signal output from the sensor. The control device 4a of the multicopter 10 may be configured to fly the multicopter 10 close to the work vehicle 100 in response to the request from the work vehicle 100.

[0067] While the multicopter 10 is flying, the control device 4a executes the operation shown in FIG. 5 . That is, the control device 4a determines whether the distance between the work vehicle 100 and the multicopter 10 is greater than a threshold. If the distance is greater than the threshold, communication is performed in a first communication mode. When the distance becomes equal to or less than the threshold, the communication mode is changed from the first communication mode to a second communication mode. FIG. 6 shows an example of communication in the first communication mode, and FIG. 7 shows an example of communication in the second communication mode. In the first communication mode shown in FIG. 6 , the control device 4a of the multicopter 10 transmits to the work vehicle 100 position information acquired by the GNSS receiver 41 and sensing information acquired by the imaging device 150 and the LiDAR sensor 160. Communication between the multicopter 10 and the work vehicle 100 is performed indirectly via the server 300. 7 , the control device 4a transmits the position information acquired by the GNSS receiver 41 and the attitude information acquired by the IMU 140 to the work vehicle 100. Furthermore, communication between the multicopter 10 and the work vehicle 100 is performed by direct wireless communication. As a result, when the multicopter 10 approaches the work vehicle 100, the position information and attitude information are transmitted to the work vehicle 100 at high frequency, making it easy for the work vehicle 100 to accurately grasp the position and attitude of the multicopter 10 based on this information. This makes it possible for the work vehicle 100 to properly align itself for the transfer of materials or harvested products without colliding with the multicopter 10.

[0068] In both the first communication mode and the second communication mode, information may be transmitted not only from the multicopter 10 to the work vehicle 100, but also from the work vehicle 100 to the multicopter 10. For example, in the first communication mode, the work vehicle 100 and the multicopter 10 may share position information and / or sensing information with each other. In the second communication mode, the work vehicle 100 and the multicopter 10 may share position information and / or attitude information with each other. By transmitting this information from the work vehicle 100 to the multicopter 10, it becomes easier for the multicopter 10 to accurately grasp the position and attitude of the work vehicle 100. This makes it possible for the multicopter 10 to properly align itself for the transfer of materials or harvested products without colliding with the work vehicle 100.

[0069] In this way, bidirectional communication may be performed between the multicopter 10 and the work vehicle 100, or unidirectional communication from one side to the other side may be performed.

[0070] Note that the changes in the information and communication methods transmitted in the first and second communication modes in the examples of Figures 6 and 7 are merely illustrative, and various modifications are possible. For example, the control device 4a of the multicopter 10 may transmit position information in the first communication mode, and in the second communication mode, transmit altitude information acquired by the altitude sensor 43 to the work vehicle 100 in addition to the position information and attitude information. Adding the altitude information allows the work vehicle 100 to more accurately grasp the position of the multicopter 10. Furthermore, the control device 4a or the control device 120 may transmit the same type of information in both the first and second communication modes, but may communicate more frequently in the second communication mode than in the first communication mode. For example, information may be transmitted at a first time interval (e.g., 0.1 seconds or more and less than 1 second) in the first communication mode, and at a shorter second time interval (e.g., 0.01 seconds or more and less than 0.1 seconds) in the second communication mode.

[0071] 6 and 7, the multicopter 10 assists the work of the work vehicle 100, but this relationship may be reversed. For example, the multicopter 10 may drive a work implement 200 as shown in FIG. 1C to perform ground work such as spraying agricultural materials such as pesticides, fertilizer, or seeds, harvesting crops, or mowing, and the work vehicle 100 may assist in transporting agricultural materials, harvested crops, or cut grass. In this case, the communication method described above can be applied in the same way.

[0072] In the above example, the multicopter 10 receives the position information of the work vehicle 100 measured by the positioning device of the work vehicle 100, and the work vehicle 100 acquires the position information of the multicopter 10 measured by the positioning device of the multicopter 10. The position information of the communication partner of each of the multicopter 10 and the work vehicle 100 is not limited to being acquired from the communication partner. For example, each of the multicopter 10 and the work vehicle 100 may estimate the position of the communication partner based on data output from its own imaging device and / or sensing device, such as a LiDAR sensor. For example, the communication partner may be recognized and its position may be determined based on image data output from an imaging device, such as a stereo camera, and / or distance data or point cloud data output from a laser sensor, such as a LiDAR sensor.

[0073] As described above, the communication method of this embodiment allows the work vehicle 100 and the multicopter 10 to share necessary information with high accuracy and in real time. This allows the work vehicle 100 and the multicopter 10 to approach each other without colliding, enabling coordinated work such as the supply of materials or the delivery of harvested crops. For example, coordinated work can be performed in a state where the work vehicle 100 and the multicopter 10 overlap without touching each other in a plan view. Such coordinated work is also referred to as "cooperative work."

[0074] In the above example, the communication mode is changed based on the comparison result between the distance between the work vehicle 100 and the multicopter 10 and one threshold value, but the communication mode may also be changed in multiple stages based on the comparison result with two or more threshold values.

[0075] Figure 8 is a flowchart showing an example in which the communication mode changes in three stages depending on the distance between the work vehicle 100 and the multicopter 10. The operation shown in Figure 8 can be executed by one or both of the control device 4a of the multicopter 10 and the control device 120 of the work vehicle 100. The following description will be given assuming that the control device 4a of the multicopter 10 executes the operation shown in Figure 8. The operations of steps S201, S202, and S208 in this example are the same as the operations of steps S101, S102, and S106, respectively, and therefore will not be described here.

[0076] In step S203, the control device 4a determines whether the distance between the work vehicle 100 and the multicopter 10 is greater than a first threshold. If the distance is greater than the first threshold, the process proceeds to step S205, where the control device 4a communicates in the first communication mode. After step S205, the process proceeds to step S208. If the distance is equal to or less than the first threshold, the process proceeds to step S204.

[0077] In step S204, the control device 4a determines whether the distance between the work vehicle 100 and the multicopter 10 is greater than a second threshold value that is smaller than the first threshold value. If the distance is greater than the second threshold value, the process proceeds to step S206, where the control device 4a communicates in the second communication mode. After step S206, the process proceeds to step S208. If the distance is equal to or less than the second threshold value, the process proceeds to step S207, where the control device 4a communicates in the third communication mode. After step S207, the process proceeds to step S208.

[0078] According to the operation shown in FIG. 8 , the communication mode can be changed to three stages depending on the distance between the work vehicle 100 and the multicopter 10. The first communication mode can be, for example, a mode in which position information is transmitted via indirect communication. The second communication mode can be, for example, a mode in which position information and attitude information are transmitted via direct communication. The third communication mode can be, for example, a mode in which position information, attitude information, and altitude information are transmitted via direct communication. In each mode, sensing information can also be transmitted. In this way, the shorter the distance between the work vehicle 100 and the multicopter 10, the more types of information can be transmitted, or the communication speed or frequency of transmission can be increased, thereby more appropriately executing information communication for cooperation between the work vehicle 100 and the multicopter 10. Note that the control devices 4a and 120 can change the communication mode to four or more stages depending on the distance between the work vehicle 100 and the multicopter 10.

[0079] Note that the information communication method in the present disclosure is not limited to the above example. Other communication methods will be exemplified below.

[0080] When the distance between the multicopter 10 and the work vehicle 100 is longer than a threshold, the control devices 4a and 120 may share the position information measured by their respective positioning devices, and when the distance is below the threshold, they may share more detailed information regarding the relative position obtained using an imaging device or beacon, etc.

[0081] The control device 4a of the multicopter 10 may switch the sensor, such as LiDAR, used for sensing depending on the relative position with respect to the work vehicle 100. For example, when the multicopter 10 is flying at a position higher than the height of the work vehicle 100, sensor data acquired by a sensor that senses below the multicopter 10 may be transmitted, and when the multicopter 10 is flying at a position lower than the height of the work vehicle 100, sensor data acquired by a sensor that senses to the side of the multicopter 10 may be transmitted.

[0082] The communication method may be changed depending on the relative speed between the work vehicle 100 and the multicopter 10 in addition to the distance between them. For example, when the relative speed is equal to or less than a threshold, communication may be performed via a public line and the server 300, and when the relative speed exceeds the threshold, direct communication may be performed between the work vehicle 100 and the multicopter 10.

[0083] <Information Display System> The control device 120 in this embodiment also functions as a display system that displays on the display device 170 the positions of the work vehicle 100 and one or more multicopters 10 flying around the work vehicle 100. The display system is a system that can display on the display device 170 the relative positions of the work vehicle 100, which is capable of performing ground work while moving, and the flying multicopters 10.

[0084] Control device 120 includes a processing device that acquires position information of work vehicle 100 and unmanned aerial vehicle 10, and displays the positions of work vehicle 100 and unmanned aerial vehicle 10 in fields (i.e., display areas) shown on display device 170 based on the position information. Display device 170 may be included in the display system, or may be an element external to the display system.

[0085] 9 is a block diagram showing an example of the hardware configuration of the control device 120. The control device 120 includes a processor 34, which is a processing device, a ROM (Read Only Memory) 35, a RAM (Random Access Memory) 36, a storage device 37, and a communication I / F 38. These components are connected to each other via a bus 39.

[0086] The processor 34 is one or more semiconductor integrated circuits, and is also called a central processing unit (CPU) or a microprocessor. The processor performs various processes by sequentially executing computer programs stored in the ROM 35. The term "processor" is broadly interpreted as including a field programmable gate array (FPGA) equipped with a CPU, a graphic processor unit (GPU), an application specific integrated circuit (ASIC), or an application specific standard product (ASSP).

[0087] The ROM 35 is, for example, a writable memory (e.g., a PROM), a rewritable memory (e.g., a flash memory), or a read-only memory. The ROM 35 stores a program that controls the operation of the processor. The ROM 35 does not have to be a single recording medium, but may be a collection of multiple recording media. Some of the collection of multiple recording media may be removable memories.

[0088] The RAM 36 provides a working area for temporarily loading the programs stored in the ROM 35 at boot time. The RAM 36 does not have to be a single recording medium, but can be a collection of multiple recording media.

[0089] The communication I / F 38 is an interface for communication between the control device 120 and other electronic components or electronic control units (ECUs). For example, the communication I / F 38 can perform wired communication in accordance with various protocols. The communication I / F 38 can also perform wireless communication in accordance with the Bluetooth (registered trademark) standard and / or the Wi-Fi (registered trademark) standard. Both standards include wireless communication standards that use frequencies in the 2.4 GHz band.

[0090] Storage device 37 may be, for example, a semiconductor memory, a magnetic storage device, an optical storage device, or a combination thereof. Storage device 37 may store, for example, map data (map information) useful for the autonomous driving of work vehicle 100, and various sensor data acquired while work vehicle 100 is traveling.

[0091] The control device 4a of the multicopter 10 may also have a hardware configuration similar to that shown in Fig. 9. As described above, the control device 4a may include, for example, a flight control device such as a flight controller and a host computer (companion computer). The companion computer may execute the above-described processes and issue flight-related commands based on the results of those processes to the flight controller.

[0092] The display device 170 in this embodiment is mounted on the work vehicle 100. The display device 170 may be built into or connected to a computer used by a user who monitors the operation of the work vehicle 100 in a location remote from the work vehicle 100. The computer used by the user may be, for example, a mobile terminal such as a smartphone or tablet computer, or may be a stationary computer such as a personal computer (PC) or workstation.

[0093] 10 is a flowchart showing an example of processing executed by processor 34 (processing device) in control device 120. In this example, processor 34 acquires map information of the area in which work vehicle 100 is located, generates a map image in which the positions of work vehicle 100 and unmanned aerial vehicle 10 are superimposed on the map, and displays the map image in the field of display device 170.

[0094] In step S301, processor 34 acquires map information of the area in which work vehicle 100 will travel. The map information is stored in advance in storage device 37 of control device 120. The map information may include, for example, position information (e.g., latitude and longitude) of the field in which work vehicle 100 will travel and the features in the surrounding area. Processor 34 acquires the map information from storage device 37. Note that processor 34 may also acquire the map information from an external device such as server 300.

[0095] In step S302, the processor 34 acquires the position information of each of the work vehicle 100 and the multicopter 10. The processor 34 acquires the position information of the work vehicle 100 output from a positioning device such as the GNSS receiver 130 in the work vehicle 100. The processor 34 acquires the position information of the multicopter 10 output from a positioning device such as the GNSS receiver 41 of the multicopter 10 via the communication devices 4c, 110.

[0096] In step S303, based on the position information and map information, processor 34 generates a map image in which the respective positions of work vehicle 100 and multicopter 10 are superimposed on a map. The map image may be, for example, an image in which icons indicating the respective positions of work vehicle 100 and multicopter 10 are superimposed on a map of a farm field. Processor 34 may acquire speed information of each of work vehicle 100 and multicopter 10 in addition to the position information, and may generate a map image that further indicates the respective movement directions of work vehicle 100 and multicopter 10 based on the speed information.

[0097] In step S304, processor 34 displays the generated map image on display device 170. Processor 34 may repeatedly execute the operations shown in steps S301 to S304 to cause display device 170 to display a moving image showing changes in the positions of work vehicle 100 and multicopter 10, respectively.

[0098] FIG. 11 is a diagram showing an example of a map image displayed on the display device 170. In this example, two multicopters 10 (drone #1 and drone #2) are flying around a tractor, which is the work vehicle 100. The processor 34 in the work vehicle 100 sequentially receives position information and speed information from each of the two multicopters 10, and displays a map image such as that shown in FIG. 11 on the display device 170. In this example, two multicopters 10 are flying around the work vehicle 100, but one or three or more multicopters 10 may also be flying around the work vehicle 100.

[0099] Communication control may be performed between the work vehicle 100 and each multicopter 10 according to the distance described above, or communication may be performed to share necessary information such as identifiers (IDs) and location information regardless of distance. Information about multicopters 10 that perform cooperative work with the work vehicle 100 as described above, as well as information about multicopters 10 that do not perform cooperative work with the work vehicle 100, may be transmitted to and displayed on the work vehicle 100. Communication between the work vehicle 100 and each multicopter 10 may be performed by direct wireless communication, or may be performed via a server 300 on the cloud.

[0100] In the example of FIG. 11 , the processor 34 generates a map image showing the positions and movement directions of each of the multicopters 10, with the position of the work vehicle 100 at the center, and displays the map image on the display device 170. More specifically, the processor 34 generates a map image including icons for each of the work vehicles 100 and multicopters 10 and arrows indicating the movement directions of each of the work vehicles 100 and multicopters 10, and displays the map image on the display device 170. The processor 34 may acquire flight path information from each multicopter 10, generate a map image including information about future flight paths, and display the map image on the display device 170. The processor 34 sequentially acquires position information and speed information for each of the work vehicles 100 and multicopters 10, and sequentially updates the display of the positions and movement directions of each of the work vehicles 100 and multicopters 10 on the map image. The information transmitted from each multicopter 10 to the work vehicle 100 includes the ID of that multicopter 10. The work vehicle 100 can identify information from each individual multicopter 10 based on the ID.

[0101] In the example shown in FIG. 11 , the processor 34 acquires operation information indicating the operation status of each multicopter 10 and, based on the operation information, displays the operation status of each multicopter 10 along with a map image on the display device 170. An example of the operation status of two multicopters 10 (drone #1 and drone #2) is shown on the right side of FIG. 11 . The operation status may include, for example, at least one of the following: the type of work being performed by the multicopter 10 (spraying, transporting, mowing, etc.), whether the multicopter 10 is flying autonomously (unmanned), the remaining flight time (or remaining energy) of the multicopter 10, and the remaining energy of the multicopter 10. In the example shown in FIG. 11 , the operation information includes the distance from the work vehicle 100, altitude, type of work, operation mode (autonomous or manual), and remaining flight time of each multicopter 10. In the example shown in FIG. 11 , the model name (manufacturer, model number, etc.) identified from the ID of each multicopter 10 is also displayed.

[0102] In the example of FIG. 11 , a dashed circle indicates a range of a predetermined distance from the position of the work vehicle 100. The processor 34 may output a warning (alert) to the display device 170 when any multicopter 10 enters within a range of the predetermined distance from the position of the work vehicle 100. In the example of FIG. 11 , one multicopter 10 (drone #2) approaches the work vehicle 100 and enters within a range of the predetermined distance. At this time, the processor 34 displays a message, "A drone is approaching," as an alert on the display device 170. If a multicopter 10 is intentionally approaching the work vehicle 100 for cooperative work with the work vehicle 100, the purpose of the work may be displayed. As shown in FIG. 11 , the processor 34 may display information indicating the purpose of the multicopter 10's approach (e.g., automatic drug supply) on the display device 170.

[0103] The alert is not limited to being displayed on the display device 170, but may also be expressed, for example, by a warning sound from a speaker, light from a light source, or vibration. The alert may change depending on the distance between the work vehicle 100 and the multicopter 10. For example, the processor 34 may change the interval between the issuance of the warning sound, vibration, or light alert depending on the distance between the work vehicle 100 and the multicopter 10. As an example, when the distance between the work vehicle 100 and the multicopter 10 falls below a first threshold as the multicopter 10 approaches the work vehicle 100, an intermittent sound with long intervals such as "beep, ..., beep, ..." may be output as an alert, and when the distance falls below a second threshold smaller than the first threshold, an intermittent sound with short intervals such as "beep, beep, beep" may be output as an alert. Note that the distance between the work vehicle 100 and the multicopter 10 may be a distance in three-dimensional space or a distance in a planar view.

[0104] 10 and 11, the processor 34 causes the display device 170 to display a map image in which a display showing the positions of the work vehicle 100 and each unmanned aerial vehicle 10 is superimposed on a map, but the display is not limited to this. The positions of the work vehicle 100 and each multicopters 10 may be displayed in other ways, such as a radar display.

[0105] In this way, the display system of this embodiment displays on the display device 170 an image showing the relative positional relationship between the work vehicle 100 capable of ground work and one or more multicopters 10 located around it (for example, within a certain distance). This allows the user of the work vehicle 100 (for example, the driver or an observer) to grasp information such as the position and speed of the multicopters 10 around the work vehicle 100. If the work vehicle 100 is, for example, a tractor equipped with a cabin and the user is aboard the tractor, it is generally difficult for the user to accurately grasp the positions of the surrounding multicopters 10. By employing the display system of this embodiment, it becomes easy for the user to immediately grasp the positions of the surrounding multicopters 10.

[0106] In the above example, information such as the positions of one or more multicopters 10 in the vicinity of the work vehicle 100 is displayed around the position of the work vehicle 100, but a similar display may be performed around the position of a specific multicopter 10. In this case, an image including the position information of one or more multicopters 10 and one or more work vehicles 100 that are present around the specific multicopter 10 may be displayed on the display device 170.

[0107] In this embodiment, the processor 34 (i.e., the processing device) included in the control device 120 in the work vehicle 100 generates a map image including information such as the positions of the work vehicle 100 and the multicopter 10, but another processing device may perform this processing. For example, the processing device 320 in the server 300 may receive necessary information from each of the work vehicle 100 and the multicopter 10, generate a map image based on that information, and send it to the display device 170. Alternatively, a processor included in the display device 170 may generate and display the map image. A similar display may be produced not only on the display device 170 within the work vehicle 100, but also on another display device, for example, a display terminal for remotely monitoring the work vehicle 100 or the multicopter 10.

[0108] The work vehicles in the above embodiments are not limited to agricultural machinery such as tractors, but may also be construction machinery. For example, the communication method and display method of the present disclosure may be applied to a system including one or more construction or civil engineering work vehicles such as backhoes, wheel loaders, and carriers, and one or more unmanned aerial vehicles.

[0109] This specification discloses the solutions described in the following items.

[0110] [Item 1] A communication system mounted on one of a work vehicle and an unmanned aerial vehicle flying around the work vehicle, comprising: a communication device that communicates with the other of the work vehicle and the unmanned aerial vehicle; and a control device that controls communication by the communication device, changing the mode of communication between the work vehicle and the unmanned aerial vehicle depending on the distance between the work vehicle and the unmanned aerial vehicle.

[0111] [Item 2] The control device of the communication system described in Item 1 acquires position information of the work vehicle from a positioning device mounted on the work vehicle, acquires position information of the unmanned aerial vehicle from a positioning device mounted on the unmanned aerial vehicle, and calculates the distance between the work vehicle and the unmanned aerial vehicle based on the position information of the work vehicle and the position information of the unmanned aerial vehicle.

[0112] [Item 3] The communication system described in Item 1, wherein the control device acquires information indicating the distance between the work vehicle and the unmanned aerial vehicle from a ranging device mounted on one of the work vehicle and the unmanned aerial vehicle.

[0113] [Item 4] The control device, when the distance between the work vehicle and the unmanned aerial vehicle is greater than a threshold, transmits position information obtained from a positioning device mounted on one of the work vehicle and the unmanned aerial vehicle via the communication device to the other of the work vehicle and the unmanned aerial vehicle, and when the distance is equal to or less than the threshold, transmits attitude information obtained from an attitude detection sensor mounted on one of the work vehicle and the unmanned aerial vehicle in addition to the position information to the other of the work vehicle and the unmanned aerial vehicle via the communication device. A communication system as described in any one of items 1 to 3.

[0114] [Item 5] A communication system described in any one of items 1 to 3, wherein the communication system is mounted on the unmanned aerial vehicle, and the control device, when the distance is greater than a threshold, transmits position information obtained from a positioning device mounted on one of the work vehicle and the unmanned aerial vehicle via the communication device to the other of the work vehicle and the unmanned aerial vehicle, and when the distance is equal to or less than the threshold, transmits altitude information obtained from an altitude sensor mounted on one of the work vehicle and the unmanned aerial vehicle from the communication device to the other of the work vehicle and the unmanned aerial vehicle in addition to the position information.

[0115] [Item 6] The control device, when the distance is greater than a threshold, transmits sensor data acquired from an external sensor mounted on one of the work vehicle and the unmanned aerial vehicle from the communication device to the other of the work vehicle and the unmanned aerial vehicle, and when the distance is equal to or less than the threshold, transmits position information and attitude information acquired from a positioning device and attitude detection sensor respectively mounted on one of the work vehicle and the unmanned aerial vehicle from the communication device to the other of the work vehicle and the unmanned aerial vehicle. A communication system as described in any one of items 1 to 3.

[0116] [Item 7] The control device of any one of items 1 to 3, wherein when the distance is greater than a threshold, the control device performs communication between the work vehicle and the unmanned aerial vehicle via an external computer, and when the distance is equal to or less than the threshold, the control device performs communication directly between the work vehicle and the unmanned aerial vehicle.

[0117] [Item 8] The communication system is mounted on the unmanned aerial vehicle, and the control device flies the unmanned aerial vehicle to the vicinity of the work vehicle in response to a request from the work vehicle, determines whether the distance between the work vehicle and the unmanned aerial vehicle is greater than a threshold while the unmanned aerial vehicle is flying, communicates in a first communication mode if the distance is greater than the threshold, and changes the communication mode from the first communication mode to a second communication mode when the distance becomes equal to or less than the threshold. A communication system as described in any one of items 1 to 7.

[0118] [Item 9] An unmanned aerial vehicle equipped with the communication system described in any one of items 1 to 8.

[0119] [Item 10] A work vehicle equipped with the communication system according to any one of items 1 to 8.

[0120] [Item 11] A communication method executed by at least one of a work vehicle and an unmanned aerial vehicle flying around the work vehicle, the communication method including: acquiring information indicating the distance between the work vehicle and the unmanned aerial vehicle; and changing the mode of communication between the work vehicle and the unmanned aerial vehicle according to the distance.

[0121] The unmanned aerial vehicle disclosed herein can be widely used not only for aerial photography, surveying, logistics, and pesticide spraying, but also for ground work related to agricultural work, transporting harvested products and agricultural materials, and the like.

[0122] 2...Rotor (propeller), 3...Rotational drive device, 4...Airframe body, 4a...Control device, 4b...Sensor group, 4c...Communication device, 5...Airframe frame, 10...Multicopter, 12...Rotor, 14...Motor, 16...ESC, 22...Rotor, 41...GNSS receiver, 41...GNSS receiver, 42...IMU, 43...Altitude sensor, 44...Imaging device, 45...LiDAR sensor, 52...Battery, 100...Work vehicle, 110...Communication device, 120...Control device, 130...GNSS receiver, 140...IMU, 150...Imaging device, 160...LiDAR sensor, 170...Display device, 180...Drive device, 300...Server, 310...Communication device, 320...Processing device

Claims

1. A communication system mounted on one of a work vehicle and an unmanned aerial vehicle flying around the work vehicle, a communication device that communicates with the other of the work vehicle and the unmanned aerial vehicle; a control device that controls communication by the communication device, and changes a mode of communication between the work vehicle and the unmanned aerial vehicle depending on the distance between the work vehicle and the unmanned aerial vehicle; A communication system comprising:

2. The control device acquiring position information of the work vehicle from a positioning device mounted on the work vehicle; acquiring position information of the unmanned aerial vehicle from a positioning device mounted on the unmanned aerial vehicle; calculating the distance between the work vehicle and the unmanned aerial vehicle based on position information of the work vehicle and position information of the unmanned aerial vehicle; The communication system of claim 1 .

3. The communication system according to claim 1 , wherein the control device acquires information indicating the distance between the work vehicle and the unmanned aerial vehicle from a distance measuring device mounted on one of the work vehicle and the unmanned aerial vehicle.

4. The control device If the distance between the work vehicle and the unmanned aerial vehicle is greater than a threshold, position information acquired from a positioning device mounted on one of the work vehicle and the unmanned aerial vehicle is transmitted to the other of the work vehicle and the unmanned aerial vehicle via the communication device; If the distance is equal to or less than the threshold value, in addition to the position information, attitude information acquired from an attitude detection sensor mounted on one of the work vehicle and the unmanned aerial vehicle is transmitted to the other of the work vehicle and the unmanned aerial vehicle via the communication device. The communication system of claim 1 .

5. the communication system is mounted on the unmanned aerial vehicle; The control device If the distance is greater than a threshold, position information acquired from a positioning device mounted on one of the work vehicle and the unmanned aerial vehicle is transmitted to the other of the work vehicle and the unmanned aerial vehicle via the communication device; If the distance is equal to or less than the threshold, in addition to the position information, altitude information acquired from an altitude sensor mounted on one of the work vehicle and the unmanned aerial vehicle is transmitted from the communication device to the other of the work vehicle and the unmanned aerial vehicle. The communication system of claim 1 .

6. The control device If the distance is greater than a threshold, sensor data acquired from an external sensor mounted on one of the work vehicle and the unmanned aerial vehicle is transmitted from the communication device to the other of the work vehicle and the unmanned aerial vehicle; If the distance is equal to or less than the threshold value, position information and attitude information acquired from a positioning device and an attitude detection sensor mounted on one of the work vehicle and the unmanned aerial vehicle, respectively, are transmitted from the communication device to the other of the work vehicle and the unmanned aerial vehicle. The communication system of claim 1 .

7. The control device If the distance is greater than a threshold, performing communication between the work vehicle and the unmanned aerial vehicle via an external computer; If the distance is equal to or less than the threshold, performing direct communication between the work vehicle and the unmanned aerial vehicle. The communication system of claim 1 .

8. the communication system is mounted on the unmanned aerial vehicle; The control device In response to a request from the work vehicle, flying the unmanned aerial vehicle to the vicinity of the work vehicle; While the unmanned aerial vehicle is flying, determining whether the distance between the work vehicle and the unmanned aerial vehicle is greater than a threshold value; If the distance is greater than the threshold, communication is performed in a first communication mode; When the distance becomes equal to or less than the threshold value, the communication mode is changed from the first communication mode to a second communication mode. The communication system of claim 1 .

9. An unmanned aerial vehicle comprising a communication system according to any one of claims 1 to 8.

10. A work vehicle equipped with the communication system according to any one of claims 1 to 8.

11. A communication method performed by at least one of a work vehicle and an unmanned aerial vehicle flying around the work vehicle, comprising: acquiring information indicating a distance between the work vehicle and the unmanned aerial vehicle; changing a mode of communication between the work vehicle and the unmanned aerial vehicle according to the distance; A communication method including: