Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
  • B64U50/00—Propulsion; Power supply
  • B64U50/10—Propulsion
  • B64U50/11—Propulsion using internal combustion piston engines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
  • B64U20/00—Constructional aspects of UAVs
  • B64U20/80—Arrangement of on-board electronics, e.g. avionics systems or wiring
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
  • B64U10/00—Type of UAV
  • B64U10/10—Rotorcrafts
  • B64U10/13—Flying platforms
  • B64U10/14—Flying platforms with four distinct rotor axes, e.g. quadcopters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
  • B64U10/00—Type of UAV
  • B64U10/10—Rotorcrafts
  • B64U10/13—Flying platforms
  • B64U10/16—Flying platforms with five or more distinct rotor axes, e.g. octocopters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
  • B64U50/00—Propulsion; Power supply
  • B64U50/10—Propulsion
  • B64U50/19—Propulsion using electrically powered motors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
  • B64U50/00—Propulsion; Power supply
  • B64U50/30—Supply or distribution of electrical power
  • B64U50/33—Supply or distribution of electrical power generated by combustion engines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
  • B64U2101/00—UAVs specially adapted for particular uses or applications
  • B64U2101/40—UAVs specially adapted for particular uses or applications for agriculture or forestry operations
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T50/00—Aeronautics or air transport
  • Y02T50/60—Efficient propulsion technologies, e.g. for aircraft

Definitions

• This disclosure relates to unmanned aerial vehicles.
• Unmanned aerial vehicles are aircraft that cannot accommodate people due to their structure, but can fly remotely or automatically.
• 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 are also called “drones,” “multirotors,” or “multicopters,” and are widely used for aerial photography, surveying, logistics, and pesticide spraying.
• Patent Document 1 describes an unmanned aerial vehicle (unmanned flying object) that changes its flight position in conjunction with the operation of agricultural machinery.
• the present disclosure provides an unmanned aerial vehicle capable of increasing payload and/or flight time and suitable for agricultural applications.
• An unmanned aerial vehicle having multiple rotors, a plurality of first rotors included in the plurality of rotors; At least one second rotor included in the plurality of rotors; and a plurality of electric motors each driving the first rotor; an internal combustion engine driving the at least one second rotor; a battery for storing a first power; a power generation device driven by the internal combustion engine to generate a second electric power; a first power control device that controls charging and discharging of the battery; a second power control device that controls power generation by the power generation device; Equipped with Each of the electric motors receives at least one of the first power and the second power; The first power control device controls the second power control device.
• the second rotary drive device 3B shown in FIG. 1A has a power transmission system 23 that is mechanically connected to the rotor 2, and an internal combustion engine 7a that provides a driving force (torque) to the power transmission system 23.
• the power transmission system 23 includes mechanical components such as gears or belts, and transmits the torque of 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 may include a gasoline engine, a diesel engine, and a hydrogen engine. Furthermore, the number of internal combustion engines 7a included in the rotary drive device 3B is not limited to one.
• the aircraft body 120 of the multicopter 100 has a control device 30 including a flight controller 32, a sensor group 72, and a communication device 74. This is basically the same as the control device 4a, the sensor group 4b, and the communication device 4c of the aircraft body 4 of the multicopter 10 described with reference to FIG. 1A.
• the storage capacity of the battery 52 has a value that allows the aircraft to continue to generate lift and control attitude by the sub-rotor 12, fly to a location where landing is possible, and land there, even if power generation by the power generation device 42 stops for some reason and lift by the main rotor 22 is lost.
• the power required to drive the sub-rotor 12 can be supplied to the ESC 16 from the power generation device 42, not from the battery 52. For this reason, even if the payload and flight time are increased, there is little need to increase the storage capacity of the battery 52 accordingly.
• the battery 52 is connected to a power circuit board 60.
• the power circuit board 60 has the function of stepping down the voltage output from the battery 52 to, for example, 24 V, 12 V, or 5 V.
• the DC voltage output from the battery 52 is converted to the desired voltage by the power circuit board 60 and then supplied to other electronic components.
• the power stepped down by the power circuit board 60 is supplied to the control device 30 and the actuator 78 via wiring 80.
• control device 30 can change the ratio (power ratio) between the first drive power output from the multiple motors 14 and the second drive power output from the main rotor drive unit 24. This point will be explained in detail below.
• the responsiveness of the motor 14 is superior to that of an internal combustion engine. If the time from when a torque command signal is input until the torque required to rotate the rotors 12 and 22 reaches the torque target value is called the "response time," then the response time of the motor is, for example, about 1/100 of the response time of an internal combustion engine. For this reason, in order to control the attitude of the multicopter 100, it is desirable to detect the difference between the current value and the target value for the attitude angle of the multicopter 100 and control the rotation speed of each of the multiple sub-rotors 12 with a high response speed so as to reduce this difference. An increase in the rotation speed of the rotor results in an increase in thrust. By adjusting the thrust of each of the multiple sub-rotors 12, it becomes possible to control the attitude of the multicopter 100 with high precision and quickly.
• FIG. 5 is a block diagram showing an example of the configuration of the battery management device 54.
• the battery management device 54 has a cell monitoring circuit 54a that monitors the state (voltage, temperature, etc.) of each of the multiple single cells included in the battery 52, and a microcontroller (Micro Controller Unit: MCU) 54b that estimates the state of the battery 52 and performs management operations for the battery 52.
• MCU Micro Controller Unit
• the cell monitoring circuitry 54a may be configured to measure the voltage of each cell and perform cell balancing during charging.
• the cell monitoring circuitry 54a may have protection circuitry to prevent overcharging and over-discharging of each cell.
• Such protection circuitry may be provided in battery packs, each of which includes multiple cells.
• the MCU 54b can obtain current measurements from the current sensor 53a, which measures the current flowing through the battery 52. It can also obtain various sensor data, such as the temperature measurements of the battery 52, from other sensors.
• the battery management device 54 can be programmed to perform various calculations, for example, to estimate the state of charge (SOC) of the battery 52.
• SOC state of charge
• the state of charge (SOC) is one of the state variables that define the state (state of charge) of the battery 52.
• the parameters that define the state of the battery 52 are not limited to the state of charge, and can include variables such as the charge amount (remaining charge), cell voltage, battery temperature, state of health (SOH), and full charge capacity (FCC).
• the battery management device 54 which functions as a first power control device, can control the electrical connection state between the wiring 80 that connects the power generation device 42 to the motor 14 and the battery 52.
• the battery management unit 54 can control the power management unit 44 , which is the second power control unit, depending on the state of the battery 52 .
• the battery management device 54 controls the power management device 44 to supply power from the power generation device 42 to the motor 14 without charging the battery 52 from the power generation device 42.
• a first reference value e.g. 60%
• the battery management device 54 controls the power management device 44 to charge the battery 52 from the power generation device 42. This charging may be continued until the state of charge (SOC) of the battery 52 reaches a second reference value (e.g., 90%).
• the first reference value may be 80% and the second reference value may be 90%.
• the first reference value and the second reference value do not need to be fixed values.
• the work plan includes information on one or more agricultural tasks to be performed by the multicopter 100.
• different work plans may be created for each multicopter 100.
• the work plan includes information on one or more agricultural tasks to be performed by each multicopter 100 and the field on which each agricultural task is performed.
• the work plan may include information on multiple agricultural tasks to be performed by each multicopter 100 over multiple work days and the field on which each agricultural task is performed. More specifically, the work plan may be a database including information on a work schedule indicating which multicopter will perform which agricultural task in which field at which time for each work day.
• FIG. 6 is a diagram for explaining an example of an agricultural management system that can be used in this embodiment.
• the agricultural management system shown in FIG. 6 includes multiple multicopters 100 and a management device 600.
• FIG. 6 also shows multiple terminal devices 400 used by multiple users.
• the management device 600 is a computer managed by a business operator who operates the agricultural management system.
• the multicopters 100, the terminal devices 400, and the management device 600 can communicate with each other via a communication network N.
• the agricultural management system may include two or less or four or more multicopters 100.
• the agricultural management system may include not only the multicopters 100 but also multiple different types of agricultural machinery, such as a tractor, a rice transplanter, and a combine harvester.
• Each multicopter 100 can perform the agricultural work assigned to it in a designated field according to instructions from the management device 600.
• the operation of the multicopter 100 may be initiated by a user (operator) from the ground, in which case the management device 600 may be used by the user or other people to create a work plan.
• the agricultural management system shown in FIG. 6 may be suitably used for managing agricultural work using multiple multicopters 100 that fly automatically or manually.
• the management device 600 may create a work plan for each multicopter 100 based on information indicating a rough plan for agricultural work input by each user using their respective terminal device 400, and may perform route planning for each multicopter 100 based on the work plan.
• the management device 600 may be a collection of multiple computers.
• the management device 600 may include a computer that creates a work plan for each multicopter 100, and a computer that performs route planning for each multicopter 100.
• the management device 600 determines the route along which each multicopter 100 should move so that each multicopter 100 performs a specified agricultural task (e.g., plowing, sowing, planting, pest control, fertilization, harvesting, etc.).
• the management device 600 refers to a map of the area in which each multicopter 100 will move, generates a route on the map along which each multicopter 100 should move, and transmits the route information to the terminal device 400 of each multicopter 100 or the user.
• Multicopters 100 capable of automatic flight move based on the received route information and perform the specified agricultural task in the field assigned to each multicopter 100. In the case of a manually flown multicopter 100, the user can operate the multicopter 100 based on the route information received by the terminal device 400.
• the multicopter 100 has an automatic flight function. That is, the multicopter 100 can fly not manually but through the action of the control device 30. In a preferred embodiment, the multicopter 100 can fly not only above the field, but also above the field automatically or by remote control.
• the control device 30 of the multicopter 100 in this embodiment can also automatically fly the multicopter 100 based on the position of the multicopter 100 and information on the target route generated by the management device 600.
• the control device 30 can also control the operation of the work machine 200. This allows the multicopter 100 to perform agricultural work using the work machine 200 while flying automatically within a farm field.
• the multicopter 100 flies while generating a local route that can avoid obstacles along the target route based on sensor data output from a group of sensors 72 such as an imaging device or LiDAR sensor.
• the management device 600 generates a target route in the field based on information about the field. For example, the management device 600 can generate a target route in the field based on various information such as the preregistered outline of the field, the area of the field, the location of the entrance and exit to the field, the size of the multicopter 100, the model or size of the work machine 200, the work content, the type of crop being cultivated, the crop growing area, the crop growing conditions, or the spacing between crop rows or ridges.
• the management device 600 can generate a target route in the field based on information input by the user using the terminal device 400 or other device, for example.
• the management device 600 generates a route in the field so as to cover, for example, the entire work area where work is performed.
• the terminal device 400 is a computer used by a user located away from the multicopter 100.
• the terminal device 400 may be a mobile terminal such as a laptop computer, smartphone, or tablet computer as shown in FIG. 6, or a stationary computer such as a desktop PC (personal computer).
• the terminal device 400 displays a setting screen on the display for the user to input information required to create a work plan (e.g., a schedule for each agricultural work).
• a work plan e.g., a schedule for each agricultural work.
• the management device 600 creates a work plan based on that information.
• the terminal device 400 may also be used to register one or more fields in which the multicopter 100 will perform agricultural work.
• the work plan in this example includes information indicating the date and time when the agricultural work will be performed, the field, the work content, and the work machine 200 to be used for each registered multicopter 100.
• the work plan is not limited to the format shown in FIG. 7 and may include other information related to the work. For example, information such as the type of pesticide or fertilizer or the amount to be applied may be included in the work plan.
• the processor provided in the management device 600 generates a route for each multicopter 100 for each work day and issues instructions for agricultural work to each multicopter 100.
• the work plan may be downloaded by the control device 30 of the multicopter 100 and stored in the storage device 37 described later. In this case, the control device 30 may autonomously start operating according to the schedule indicated by the work plan stored in the storage device 37.
• the management device 600 may create a work plan based not only on information indicating the approximate timing of agricultural work, but also on information input by each user using the terminal device 400. For example, the management device 600 may create a work plan based on information indicating a rough plan for each type of agricultural work in one or more fields managed by each user.
• FIG. 8 is a diagram showing an example of a setting screen 760 displayed on the display screen of the terminal device 400.
• the processor of the terminal device 400 starts application software for creating a work plan, and causes a setting screen 760 such as that shown in FIG. 8 to be displayed on the display screen.
• the user can input outline plan information required for creating a work plan on this setting screen 760.
• the period input by the user is displayed in the period setting section 761.
• the user inputs the period during which the user wishes to perform the farm work.
• the days included in the input period are set as candidate days for performing the farm work.
• the time setting section 762 displays the work time input by the user.
• the user inputs the work time for which the user wishes to perform the farm work.
• the work time is specified by a start time and an end time.
• the input work time is set as a candidate for the time when the farm work will be performed.
• the crop variety selection section 763 displays a list of crop varieties to be cultivated (i.e., planted). The user can select the desired variety from the list. In the example of Figure 8, the rice variety "Koshiibuki" has been selected.
• the task selection section 765 displays multiple farm tasks necessary to cultivate the selected crop.
• the user can select one farm task from among the multiple farm tasks.
• "plowing" has been selected from among the multiple farm tasks.
• the selected "plowing” is set as the farm task to be performed.
• the machine selection section 766 is a section for setting the multicopter to be used in the agricultural work.
• the type or model of the multicopter registered in advance by the management device 600, and the type or model of the work implement 200 that can be used, etc. can be displayed in the machine selection section 766.
• the user can select a specific machine from the displayed machines.
• a work implement 200 with the model number "XX4511" is selected. In this case, that work implement 200 is set as the machine to be used in the agricultural work.
• the names of multiple fertilizers that have been registered in advance are displayed in the fertilizer selection section 767.
• the user can select a specific fertilizer from the multiple fertilizers displayed.
• the selected fertilizer is set as the fertilizer to be used in the farm work.
• the spray amount setting section 770 displays the numerical value input from the input device 420.
• the input numerical value is set as the spray amount.
• the communication device of the terminal device 400 transmits the entered information to the management device 600.
• the processor of the management device 600 stores the received information in a storage device.
• the information on agricultural work managed by the management device 600 is not limited to the above.
• the type of pesticide to be used in the field and the amount to be sprayed may be set on the setting screen 760.
• Information on agricultural work other than the agricultural work shown in FIG. 8 may also be set.
• the management device 600 creates a work plan for each multicopter 100 to perform agricultural work based on information received from each user's terminal device 400. For example, the management device 600 determines the actual work date and work time of the agricultural work to be performed by each multicopter 100. For example, the management device 600 determines the date and time of agricultural work in each field by comprehensively considering the number, distribution, and usage status of the multicopter 100, the distribution of fields in which agricultural work is performed in the area, the work date and time desired by each user, and the estimated work period in the area. An algorithm using artificial intelligence (AI), such as a deep neural network, may be used to determine the date and time of agricultural work in each field. The management device 600 notifies the terminal device 400 used by the user of the determined date and time of agricultural work.
• AI artificial intelligence
• the management device 600 executes a route plan for each multicopter 100 for each work day based on the determined date and time when the agricultural work will be performed in each field.
• the battery management device 54 in this embodiment can control the power management device 44 to efficiently increase or decrease the amount of power generation while monitoring the state of the battery 52 (particularly the charging rate). That is, as described below, the amount of power generation can be increased immediately before the work machine 200 starts to operate. Since the battery 52, such as a lithium-ion battery, is prone to deterioration if kept in a fully charged state, the process of increasing the charging rate in line with the start of work by the work machine 200 is also effective in extending the life of the battery 52. Such control of the charging rate is described below.
• the first reference value may be 80% and the second reference value may be 90%.
• the first reference value and the second reference value do not need to be fixed values.
• the battery management device 54 can control the charging rate of the battery 52 according to flight conditions including the flight altitude of the multicopter 100.
• the flight conditions are various parameters that determine the power (power consumption) consumed by the multicopter 100 per unit time during flight, such as flight altitude, flight speed, wind direction and speed during flight, and payload size (weight).
• the control device 30 in this embodiment calculates an estimated value of power consumption based on the above parameters that define the flight conditions.
• the battery management device 54 in this embodiment is configured to determine whether or not the vehicle can descend to a possible landing point and land using only the power currently stored in the battery 52, based on the estimated value of power consumption obtained from the control device 30.
• the battery management device 54 starts a charging operation to increase the charging rate of the battery 52.
• Such a change in the first reference value may be performed according to the content of the work performed by the multicopter 100. This is because the power consumption changes depending on the content of the work. The details of the operation of the multicopter 100 will be described later.
• the range with the first reference value as the lower limit and the second reference value as the upper limit is the "target range" of the charging rate control performed by the battery management device 54. It is preferable to change this target range depending on the flight state or the working state, as described above. For example, when the battery 52 is used as an emergency backup power source when the power generation device 42 fails, the power (first power) stored in the battery 52 only needs to be large enough to descend to the ground and land without using the power (second power) generated by the power generation device 42. In such a case, the power (first power) stored in the battery 52 can be smaller the lower the flight altitude. Therefore, for example, the lower limit (first reference value) of the target range of the charging rate (SOC) can be changed depending on the flight altitude.
• SOC target range of the charging rate
• FIG. 9 is a side view showing a schematic diagram of the lower limit (first reference value) of the target range of the state of charge (SOC) when the height (flight altitude) of the multicopter 100 from the ground GR is h4, h3, h2, or h1 (h4>h3>h2>h1>0).
• FIG. 10 is a graph showing a schematic diagram of an example of the relationship between the height of the multicopter 100 from the ground GR and the lower limit (first reference value) of the target range of the state of charge (SOC).
• the battery management device 54 controls the power management device 44 to increase the amount of power generation and charge the battery 52.
• the first reference value changes stepwise according to the flight altitude, but may change linearly or in a curve.
• the first reference value of the state of charge (SOC) is 50% or more, but when the multicopter 100 flies or performs ground operations at a low altitude of, for example, 5 meters or less, the first reference value may be set to, for example, 50% or less.
• the first reference value may be changed depending on whether the multicopter 100 is working in a field that is the subject of ground work or flying and traveling in an area other than the field.
• the battery management device 54 can control the charging rate of the battery 52 depending on the distance from the multicopter 100 to a possible landing point.
• the technical significance of controlling the charging rate according to the flight altitude is that the power consumption required for the multicopter 100 at that flight altitude to descend and land depends on the flight altitude.
• the multicopter 100 flies at a position where it cannot land even if it descends directly downward. In such cases, it is preferable for the multicopter 100 to control the charging rate of the battery 52 based on the power consumption that takes into account the distance to a possible landing point.
• the control device 30 measures or estimates the position (self-position) of the multicopter 100 during flight based on sensor data obtained from the group of sensors. The distance from that position to a possible landing location may then be calculated based on map information or the like, and the first reference value may be determined based on that distance. Such distance calculations are not limited to being performed by the control device 30, but may be performed by a higher-level computer, a computer in the ground station 6, or one or more computers connected to a communication network described below.
• the battery management device 54 of the multicopter 100 can then perform charging processing through communication between those computers and the multicopter 100 to achieve the charge rate required to fly the distance to the landing location and land.
• the battery management device 54 can control the power management device 44 to control the amount of power generated by the power generation device 42 when charging the battery 52.
• the battery management unit 54 acquires a target range for a parameter (first parameter) such as the state of charge (SOC) that defines the state of the battery 52.
• the target range can be specified by a first reference value that defines a lower limit and a second reference value that defines an upper limit.
• the target range can be provided to the battery management unit 54 from the control unit 30.
• the control unit 30 can estimate the required power based on a known flight plan or operation plan and determine the target range, or can acquire the target range from a higher-level computer or ground station 6.
• control device here is not limited to the control device 30 in FIG. 4, but may include its higher-level computer, a ground station computer, and/or a cloud-based computer.
• control device 30 in FIG. 4 controls not only the state of the power source but also the operation of the main rotor drive unit 24 and the motor 14.
• the control device 30 can supply at least a portion of the power (first power) from the battery 52 and the power (second power) from the power generation device 42 as third power from the power supply device 46 to the work machine 200.
• control device 30 may start charging the battery 52 or increase the amount of power generated by the power generation device 42 before the operation begins.
• Examples of electrical connection between the power receiving terminal 210 and the power transmitting terminal 76A include direct contact that allows current to flow, a connection via a conductive cable or wiring, and a connection via wireless power transmission.
• Examples of electrical connection between the communication terminals 216 and 76B also include direct contact that allows current to flow, a connection via a communication cable or wiring, and a wireless connection.

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• Engineering & Computer Science (AREA)
• Aviation & Aerospace Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Remote Sensing (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Charge And Discharge Circuits For Batteries Or The Like (AREA)
• Control Of Multiple Motors (AREA)

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• 2022
  • 2022-12-27 JP JP2024567020A patent/JPWO2024142237A1/ja active Pending
  • 2022-12-27 EP EP22970031.5A patent/EP4620842A1/en active Pending
  • 2022-12-27 WO PCT/JP2022/048180 patent/WO2024142237A1/ja not_active Ceased
• 2025
  • 2025-06-24 US US19/246,743 patent/US20250313358A1/en active Pending

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