Aircraft and method for controlling the aircraft

Abstract

This flying body comprises: a communication device; a receiver that acquires a current position; a flight controller that controls flight and is able to transmit current position information by using the communication device; a plurality of driving devices that respectively drive different propulsion mechanisms among a plurality of propulsion mechanisms; a distributor that distributes supplied power to each of the plurality of driving devices; a power source module that supplies power from a battery to the communication device, the receiver, and the flight controller via a first power path, and supplies the power from the battery to the distributor via a second power path; and a blocking device that, when an abnormality occurs, blocks the supply of power from the power source module to the distributor via the second power path.

Description

Technical Field

[0001] The present disclosure relates to an aircraft and a method for controlling an aircraft.

Background Art

[0002] Conventionally, as aircraft, various manned aircraft and various unmanned aircraft are known. For example, U.S. Patent Application Publication No. 2017 / 0106986A1 (Patent Document 1) discloses an unmanned aircraft equipped with a parachute. When the unmanned aircraft of Patent Document 1 detects a crash or the like, it deploys the parachute and stops supplying power to the motor that rotates the propeller. Specifically, in the unmanned aircraft of Patent Document 1, a power source and a motor that rotates the propeller are directly connected by wiring. When the unmanned aircraft of Patent Document 1 detects a crash or the like, it physically disconnects the above connection between the power source and the motor. Thereby, the power supply to the motor is stopped.

[0003] International Publication No. 2019 / 216204A1 (Patent Document 2) discloses a current interruption device used for an unmanned aircraft equipped with a parachute. The current interruption device interrupts the supply of current to the electrical equipment of the unmanned aircraft. Thereby, the occurrence of poor deployment of the parachute when the unmanned aircraft crashes (during the crash) is prevented. Further, the occurrence of contact accidents between the operating propeller and people after the crash is prevented.

[0004] International Publication No. 2017 / 030034A1 (Patent Document 3) discloses an unmanned aircraft capable of charging a battery by a power generation device during flight in order to extend the flight distance. When the unmanned aircraft detects a crash, the unmanned aircraft stops charging the battery from the power generation device. Thereby, the spread of accident damage after the crash of the unmanned aircraft is prevented.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] The unmanned aerial vehicle described in Patent Document 1 is equipped with an electronic speed controller (ESC) that drives the motor described above. Specifically, the electronic speed controller is a motor driver (amplifier) ​​that controls the rotational speed of the motor by supplying current to the motor. The flight speed of the unmanned aerial vehicle is controlled by the electronic speed controller. Therefore, even if the connection between the power supply and the motor is disconnected as described above, current will still flow from the power supply to the motor via the electronic speed controller. Consequently, in the unmanned aerial vehicle described in Patent Document 1, it is not actually possible to stop the rotation of the propeller by disconnecting the power supply as described above.

[0007] The unmanned aerial vehicle (UAV) equipped with the current interruption device described in Patent Document 2 cuts off the supply of current to the UAV's electrical equipment by the current interruption device in the event of a crash. Therefore, in the event of a crash (parachute descent) of the UAV, the UAV cannot calculate its current position or communicate with external devices on the ground. Consequently, external devices on the ground cannot determine the current position of the UAV.

[0008] In the unmanned aerial vehicle described in Patent Document 3, even if a crash of the unmanned aerial vehicle is detected, power continues to be supplied from the battery to the motor that rotates the propeller. In other words, the propulsion mechanism (propeller and motor) of the unmanned aerial vehicle continues to operate.

[0009] This disclosure has been made in view of the above-mentioned problems, and its purpose is to provide an aircraft and a method for controlling the aircraft that can shut down all propulsion mechanisms by shutting off one power path when a predetermined abnormality occurs, and that can transmit information about its current position to an external device even after the power path has been shut off. [Means for solving the problem]

[0010] In accordance with a certain aspect of this disclosure, the aircraft comprises a battery, a plurality of propulsion mechanisms, a communication device for wirelessly communicating with external equipment, a receiver that acquires the aircraft's current position by receiving radio waves transmitted from a plurality of positioning satellites, a flight controller that controls the flight of the aircraft and can transmit information about its current position using the communication device, a plurality of drive units, each of which is communicatively connected to the flight controller and each drives a different propulsion mechanism from the plurality of propulsion mechanisms, a distributor that distributes the power supplied to each of the plurality of drive units, a power module that supplies power from the battery to the communication device, the receiver, and the flight controller via a first power path, and to the distributor via a second power path, and a shut-off device that cuts off the power supply from the power module to the distributor via the second power path if a predetermined abnormality occurs in the aircraft.

[0011] In other aspects of this disclosure, the aircraft supplies power from an internal battery via a first power path to a flight controller that controls the aircraft's flight, a communication device for wireless communication with external devices, and a receiver that calculates the aircraft's current position, and also supplies power via a second power path to a distributor that distributes power to each of a plurality of drive units. Each drive unit drives different propulsion mechanisms from a plurality of propulsion mechanisms based on commands from the flight controller. The aircraft control method includes the steps of cutting off the power supply to the distributor via the second power path when a predetermined abnormality occurs in the aircraft, and transmitting information of the current position to an external device using the communication device when a predetermined abnormality occurs. [Effects of the Invention]

[0012] According to this disclosure, if a predetermined abnormality occurs in the aircraft, it is possible to shut down all propulsion mechanisms by interrupting one power path, and even after interrupting the power path, it is possible to transmit information about the current position to an external device. [Brief explanation of the drawing]

[0013] [Figure 1] This is a diagram showing a drone in flight. [Figure 2] This diagram shows a drone descending with its parachute deployed. [Figure 3] This is a block diagram illustrating the hardware configuration of the drone. [Figure 4] This is a diagram illustrating a specific example of a circuit breaker. [Figure 5] This is a flowchart illustrating the processing flow performed by the drone. [Figure 6] This figure shows the state of the power path before interruption in the first modified example of the circuit breaker. [Figure 7] This figure shows the state after the power path has been interrupted in the first modified example of the circuit breaker. [Figure 8] This is a diagram illustrating a second modified example of the circuit breaker. [Figure 9] This is a block diagram illustrating the hardware configuration of other drones. [Modes for carrying out the invention]

[0014] Embodiments according to the present invention will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions of them will not be repeated.

[0015] Hereinafter, as an example of an aircraft, a drone will be taken as an example for explanation. More specifically, as the drone, a quadcopter will be taken as an example for explanation. Even more specifically, a quadcopter having rotary wings will be taken as an example for explanation. Note that the present disclosure is also applicable to various manned aircraft (other examples of aircraft) such as "flying cars".

[0016] <A. Overview of the Drone> The drone according to the present embodiment is capable of automatic flight control and manual flight control by an operator's remote controller operation. FIG. 1 is a diagram showing a state where the drone is flying. FIG. 2 is a diagram showing a state where the drone is descending with a parachute ejected.

[0017] As shown in FIGS. 1 and 2, the drone 1 includes a main body 2, four arms 3A, 3B, 3C, 3D, four propulsion mechanisms 4A, 4B, 4C, 4D, an ejection device 5, a communication unit 6, and a support member 18. Each of the propulsion mechanisms 4A, 4B, 4C, 4D includes a propeller 41 (see FIG. 2) and a motor 42.

[0018] In the following, for convenience of explanation, any one of the arms 3A, 3B, 3C, 3D will also be referred to as "arm 3". Similarly, any one of the propulsion mechanisms 4A, 4B, 4C, 4D will also be referred to as "propulsion mechanism 4".

[0019] The arm 3 is attached to the main body 2. The arm 3 has a base end portion and a tip end portion. The base end portion of the arm 3 is attached to the main body 2. In this example, the arm 3 extends from the side surface of the main body 2.

[0020] The propulsion mechanism 4 is attached to the tip end portion of the arm 3. The motor 42 is attached to the tip end portion of the arm 3. The propeller 41 is attached to the rotation shaft (not shown) of the motor 42.

[0021] The ejection device 5 is attached to the upper surface (top surface) of the main body 2. The ejection device 5 houses a parachute 51. When a predetermined abnormality occurs in the drone 1, the ejection device 5 ejects the parachute 51 (see Fig. 2). The ejection device 5 detects the fall of the drone 1 and instantaneously deploys the parachute by activating a gas generator built into the ejection device 5. As the gas generator, a gunpowder-type gas generator (pyrotechnics) may be used, or a non-gunpowder-type gas generator such as a cylinder type may be used.

[0022] In this example, the support member 18 extends upward from the connection point between the arm 3 and the main body 2. The support member 18 is a hollow pipe. Wires for the communication unit 6 pass through the inside of the support member 18. In this example, the communication unit 6 is supported by the support member 18 so as to be located above the main body 2.

[0023] Although an example of a drone 1 having four arms 3 and four propulsion mechanisms 4 is given, the number of arms and the number of propulsion mechanisms are not limited to this.

[0024] <B. Hardware Configuration and Processes Executed> Fig. 3 is a block diagram for explaining the hardware configuration of the drone 1. As shown in Fig. 3, the drone 1 can communicate with a ground device 900. The ground device 900 includes a remote controller 901 and a ground control station 902. In Fig. 3, the main power path is represented by a solid line, and the main signal path is represented by a dashed line.

[0025] In addition to the aforementioned propulsion mechanisms 4A, 4B, 4C, 4D, launching device 5, and communication unit 6, Drone 1 is equipped with drive units (ESC: Electronic Speed ​​Controller) 7A, 7B, 7C, 7D, flight controller (Autopilot) 8, battery 9, power module 10, cutoff device (FTS: Flight Termination System) 11, distributor 12, battery 13, trigger device (ATS: Auto Trigger System) 14, and sensor 15. For the sake of explanation, in the following, any one of the drive units 7A, 7B, 7C, and 7D will also be referred to as "drive unit 7".

[0026] As described above, the propulsion mechanism 4 includes a propeller 41 and a motor 42. The motor 42 has a magnet 421 and a coil 422. The type of motor 42 is not particularly limited. For example, a brushless DC (Direct Current) motor, a brushed DC motor, or an AC (Alternating Current) motor can be used as the motor 42. The drive unit 7 includes an MCU (Micro Controller Unit) 71 and a current driver 72.

[0027] The flight controller 8 includes an MCU 81, an inertial measuring unit (IMU) 82, and a barometric altimeter 83. The MCU 81 has an attitude estimation unit 811 and a determination unit 812 as functional blocks. The MCU 81 is communicatively connected to the inertial measuring unit 82 and the barometric altimeter 83.

[0028] The cutoff device 11 includes a current switch 111. The trigger device 14 includes an MCU 141 and a sensor 142. The sensor 142 detects the acceleration, angular velocity, attitude angle, and altitude changes of the drone 1.

[0029] Specifically, MCU71,81,141 include a CPU (Central Processing Unit), memory such as ROM (Read Only Memory) and RAM (Random Access Memory), and I / O (Input / Output) circuits (not shown). Programs and data are stored in the memory. For example, the memory of MUC81 stores data indicating the flight route of drone 1.

[0030] The communication unit 6 includes a GNSS (Global Navigation Satellite System) receiver 61, a wireless module 62, and an LTE (Long Term Evolution) module 63.

[0031] Battery 9 is a rechargeable battery (secondary battery). Battery 9 is connected to the power module 10.

[0032] The power module 10 supplies power from the battery 9 to the flight controller 8 and the communication unit 6 via power path R1. In this example, the communication unit 6 is powered via the flight controller 8. The power module 10 also supplies power from the battery 9 to the distributor 12 via power path R2. More specifically, the power module 10 supplies power from the battery 9 to the distributor 12 via the circuit breaker 11. In this way, the power module 10 branches the power path from the battery 9 into two power paths R1 and R2.

[0033] In the power path R2, the connector terminals of the power module 10 and the connector terminals of the distributor 12 are connected via wiring. To reduce heat generation due to contact resistance caused by the wiring, it is preferable that the connector terminals of the power module 10 and the connector terminals of the distributor 12 are gold-plated.

[0034] The distributor 12 distributes the supplied power to each of the four drive units 7. The distributor 12 supplies the power supplied by the power path R2 to each of the four drive units 7. More specifically, the distributor 12 supplies power to the current driver 72 of each of the four drive units 7. Although not shown by solid lines, power is also supplied to each MCU 71. The current driver 72 and the coil 422 of the motor 42 are connected by wiring.

[0035] The drive unit 7 is connected to the flight controller 8 in a communicative manner. Based on commands from the flight controller 8, the drive unit 7 drives the corresponding propulsion mechanism 4. More specifically, the drive unit 7 adjusts the thrust of the corresponding propulsion mechanism 4 based on commands from the flight controller 8. Specifically, the drive unit 7A adjusts the thrust of the corresponding propulsion mechanism 4A. Similarly, the drive units 7B, 7C, and 7D adjust the thrust of the propulsion mechanisms 4B, 4C, and 4D, respectively. In this way, the drive unit 7 functions as a control device for the propulsion mechanism 4.

[0036] More specifically, the MUC71 receives commands from the MUC81 of the flight controller 8. Based on these commands, the MCU71 controls the current that the current driver 72 supplies to the coil 422 of the motor 42. By controlling the current supplied to the coil 422 in this way, the rotational speed of the motor 42 is controlled. This allows the rotational speed of the propeller 41 to be controlled.

[0037] The GNSS receiver 61, the wireless module 62, and the LTE module 63 are communicated with the MCU 81 of the flight controller 8. The GNSS receiver 61, the wireless module 62, and the LTE module 63 receive power from the flight controller 8. The GNSS receiver 61, the wireless module 62, and the LTE module 63 operate on power from the battery 9.

[0038] The GNSS receiver 61 receives radio waves transmitted from multiple positioning satellites (not shown) and obtains the current position of the drone 1 based on the received radio waves. The GNSS receiver 61 periodically sends information indicating the current position to the flight controller 8. More specifically, the GNSS receiver 61 periodically sends the latitude and longitude information of the drone 1 as position information to the MCU 81.

[0039] The wireless module 62 is a communication module for communicating with the remote controller 901. Communication between the wireless module 62 and the remote controller 901 is used when manually controlling the drone 1 within the operator's line of sight. Therefore, this communication is real-time. Commands from the remote controller 901 are input to the MCU 81 via the wireless module 62.

[0040] The LTE module 63 is a communication module for communicating with the ground control station 902 via a base station (not shown). Communication between the LTE module 63 and the ground control station 902 is used when flying the drone 1 over several kilometers using automatic piloting. In this example, the MUC 81 transmits the location information of the drone 1 to the ground control station 902 via the LTE module 63. The timing of the transmission of this location information will be described later.

[0041] The inertial measurement device 82 periodically measures the angular velocity and acceleration of the drone 1 in three-dimensional space. The barometric altimeter 83 periodically measures the altitude from the ground surface and sea surface.

[0042] The flight controller 8 controls the flight of the drone 1. The flight controller 8 enables both automatic piloting and manual piloting via remote control operation by the operator.

[0043] In autonomous flight mode, the flight controller 8 controls the flight of the drone 1 based on a predetermined flight route. More specifically, the MCU 81 of the flight controller 8 achieves autonomous flight of the drone 1 based on the current position acquired by the GNSS receiver 61, the detection results from the inertial measurement device 82, and the detection results (altitude) from the barometric altimeter 83. As described above, the flight controller 8 can transmit information about the current position of the drone 1 using the LTE module 63, which is a communication device.

[0044] More specifically, the attitude estimation unit 811 of the MCU81 estimates the attitude of the drone 1 based on the detection results from the inertial measurement device 82. The determination unit 812 of the MCU81 determines whether the estimated attitude is abnormal or not based on predetermined criteria. If the MCU81 determines that the estimated attitude is abnormal, it transmits a predetermined signal to the trigger device 14.

[0045] Based on the occurrence of a predetermined abnormality in the drone 1, the flight controller 8 transmits information about the current location of the drone 1 to the ground control station 902 using the LTE module 63.

[0046] The flight controller 8 may transmit information about the current position of the drone 1 to the ground control station 902, provided that the drone has landed using the parachute 51. The drone 1 can determine that it has landed if its current position does not change for a certain period of time or longer. Alternatively, the drone 1 can determine that it has landed based on the detection results of the barometric altimeter 83. The drone 1 can also determine that it has landed based on the detection results of the inertial measurement device 82.

[0047] The launch device 5 includes a parachute. The launch device 5 launches the parachute 51 when the above-described predetermined abnormality occurs in the drone 1. In this example, the launch device 5 launches the parachute 51 regardless of whether the drone is under automatic or manual control.

[0048] The circuit breaker 11 cuts off the power supply from the power module 10 to the distributor 12 via the power path R2 if the above-described predetermined abnormality occurs. Specifically, the circuit breaker 11 cuts off the power supply to the distributor 12 by the operation of the current switch 111. In this example, the circuit breaker 11 cuts off the power supply to the distributor 12 regardless of whether the system is in automatic or manual operation mode.

[0049] The trigger device 14 is powered by the battery 13. The trigger device 14 activates the shut-off device 11 and the ejection device 5 based on the occurrence of a predetermined abnormality in the drone 1. Specifically, the MCU 141 sends a predetermined signal (command) to the ejection device 5, which then ejects the parachute 51 to the outside. The MCU 141 sends a predetermined signal (hereinafter also referred to as the "current shut-off command signal") to the shut-off device 11, which activates the current switch 111 of the shut-off device 11. This action cuts off the power supply from the power module 10 to the distributor 12 via the power path R2. As a result, the drone 1 is forced to stop autonomous flight.

[0050] The current cutoff command signal described above should preferably be robust against voltage fluctuations caused by electromagnetic noise. For example, the current cutoff command signal is preferably a signal whose variable is the holding time of a high level voltage.

[0051] Examples of predetermined abnormalities include when the estimated attitude is abnormal or when the drone deviates from the planned flight path. If the flight controller 8's MCU 81 determines that the drone 1's attitude is abnormal, or if the MCU 81 determines that the drone has deviated from its flight path, the trigger device 14's MCU 141 activates the shut-off device 11 and the ejection device 5.

[0052] The trigger device 14 may also determine whether a predetermined abnormality has occurred based on the detection result of the sensor 142. The type of abnormality is not particularly limited, as long as it is one of the pre-set types.

[0053] In this example, the trigger device 14 causes the cutoff device 11 to cut off the power supply to the distributor 12 via the power path R2, and then, when a predetermined condition is met, causes the injection device 5 to eject the parachute 51. Specifically, the trigger device 14 causes the cutoff device 11 to cut off the power supply to the distributor 12 via the power path R2, and then, after a predetermined time (for example, 1 second) has elapsed, causes the injection device 5 to eject the parachute 51.

[0054] The predetermined time is preferably 1.5 seconds or less. It is preferable that the predetermined time be set to be longer than the time it takes for the propeller 41 to stop rotating.

[0055] Sensor 15 detects whether or not the ejection device 5 is operating. Sensor 15 is connected to the flight controller 8 for communication. If the above-described predetermined abnormality occurs, the flight controller 8 uses the LTE module 63 to transmit to the ground control station 902 that the flight has been forcibly stopped and the result detected by sensor 15. The flight controller 8 may also transmit information indicating the type of abnormality to the ground control station 902.

[0056] Figure 4 is a diagram illustrating a specific example of the interruption device 11. As shown in Figure 4, the interruption device 11 includes a transistor 111A that functions as a current switch 111.

[0057] Transistor 111A is installed between the power module 10 and the distributor 12, and when it is ON, it supplies current from the power module 10 to the distributor 12 via the power path R2. In this example, transistor 111A is a bipolar transistor. More specifically, transistor 111A is an npn type transistor.

[0058] The circuit breaker 11 turns off transistor 111A when the aforementioned predetermined abnormality occurs. By switching the state of transistor 111A from the ON state to the OFF state, the circuit breaker 11 cuts off the power supply from the power module 10 to the distributor 12 via the power path R2.

[0059] Note that the transistor 111A is not limited to an npn bipolar transistor. The transistor 111A may be a pnp bipolar transistor. Also, the transistor 111A may be a field effect transistor (unipolar transistor). In this case, the transistor 111A may be a junction field effect transistor (FET) or a MOS field effect transistor. Further, the transistor 111A may be an insulated gate bipolar transistor (IGBT).

[0060] The transistor 111A generates heat when energized. Therefore, in order to prevent the temperature of the transistor 111A from exceeding the rated temperature, the cutoff device 11 preferably has a heat sink member that dissipates the heat of the transistor 111A. The cutoff device 11 may have a heat dissipation aluminum substrate or an electric cooling fan instead of or together with the heat sink member.

[0061] When the transistor 111A is switched from the on state to the off state, a surge voltage is generated. In order to prevent the transistor 111A from being destroyed by the surge voltage, the cutoff device 11 preferably has a snubber circuit. The snubber circuit includes at least one of a resistor and a capacitor.

[0062] <C. Control Structure> Figure 5 is a flowchart for explaining the flow of processing executed by drone 1. As shown in Figure 5, in step S1, drone 1 starts flying. In step S2, drone 1 determines whether any of the predetermined abnormalities described above have occurred in drone 1. If drone 1 determines that no abnormality has occurred (NO in step S2), the process proceeds to step S3. In step S3, drone 1 determines whether it has reached the destination. If it is determined that it has reached the destination (YES in step S3), drone 1 ends the series of processes. If it is determined that it has not reached the destination (NO in step S3), drone 1 returns the process to step S2.

[0063] If it is determined that an abnormality has occurred (YES in step S2), in step S4, drone 1 operates the blocking device 11. In step S5, drone 1 determines whether a predetermined time (for example, 1 second) has elapsed since operating the blocking device 11.

[0064] If it is determined that the predetermined time has elapsed (YES in step S5), in step S6, drone 1 operates the ejection device 5. That is, drone 1 ejects the parachute 51. If it is determined that the predetermined time has not elapsed (NO in step S5), drone 1 returns the process to step S5.

[0065] In step S7, drone 1 periodically transmits position information indicating its current position to the ground device 900. Specifically, by a base station device (not shown) installed around drone 1 receiving the position information of drone 1, the ground control station 902 can acquire the position information.

[0066] <D. Parentheses> (1) Referring to Figures 2 and 3, the drone 1, which is an unmanned aerial vehicle, comprises, as described above, (a) a battery 9, (b) multiple propulsion mechanisms 4 (4A~4B), (c) an LTE module (communication device) 62 for wireless communication with an external device, the ground equipment 900 (more specifically, the ground control station 902), (d) a GNSS receiver 61 that acquires the current position of the drone 1 by receiving radio waves transmitted from multiple positioning satellites, (e) a flight controller 8 that controls the flight of the drone 1 and can transmit current position information using the LTE module 62, and (f) each of the flight controllers The drone 1 comprises (g) a plurality of drive units 7 (7A~7D) that are communicably connected to the R8 and each drive a different propulsion mechanism 4 from a plurality of propulsion mechanisms 4, (h) a power module 10 that supplies power from the battery 9 to the LTE module 62, the GNN receiver 61, and the flight controller 8 via the power path R1, and also supplies power to the power module 12 via the power path R2, and (i) a shut-off device 11 that cuts off the power supply from the power module 10 to the power module 12 via the power path R2 if a predetermined abnormality occurs in the drone 1.

[0067] According to the above configuration, if a predetermined abnormality occurs, the power path R2 is shut off. Therefore, the power supply from the battery 9 to all drive units 7 via the distributor 12 is cut off. Furthermore, the shutdown of the power supply to the drive units 7 stops the operation of all propulsion mechanisms 4. In this way, it is possible to shut down all propulsion mechanisms 4 by shutting off a single power path R2.

[0068] Furthermore, even if power path R2 is interrupted, power supply to the LTE module 62, GNN receiver 61, and flight controller 8 via power path R1 continues. Therefore, according to the drone 1, even after power path R2 is interrupted, it is possible to transmit current location information to the ground device 900.

[0069] Furthermore, the drone 1 includes a parachute 51 (Figure 2) and is further equipped with a launching device 5 that launches the parachute 51 in the event of the predetermined abnormality described above. Therefore, even if all propulsion mechanisms 4 are shut down due to the interruption of the power path R2 based on the occurrence of the predetermined abnormality, the above configuration can prevent the drone 1 from crashing.

[0070] Furthermore, the advantages of Drone 1 will be explained below by providing four comparative examples. As a first comparative example, let's consider a scenario where the above-mentioned anomaly causes the battery power supply to the entire drone to stop. In this case, at least the flight controller, GNSS receiver, and communication equipment for communicating with ground facilities will not function. Therefore, in such a case, the ground operator cannot obtain the drone's latitude and longitude. Consequently, the operator cannot determine the drone's landing position. Therefore, the operator cannot recover the drone.

[0071] In contrast, with the drone 1 according to this embodiment, even if the above-mentioned abnormality occurs, the flight controller 8, the GNSS receiver 61, and the LTE module 62 can continue to operate, so the operator can accurately know the landing position of the drone 1. Therefore, the recovery of the drone becomes easier.

[0072] As a second comparative example, let's consider a scenario where the flight controller executes its propulsion system shutdown function when an anomaly occurs. In this case, if the flight controller itself malfunctions (an anomaly occurs), it cannot shut down multiple propulsion systems. Therefore, multiple propulsion systems will continue to operate while the parachute is deployed. In this case, there is a risk of interference between the propulsion systems and the parachute. For example, the parachute cords (lines) may become entangled with the propellers. Consequently, the drone may crash. Furthermore, even if there is no interference between the propulsion systems and the parachute, the drone will continue to fly using the propulsion systems.

[0073] In contrast, with the drone 1 according to this embodiment, if the above-mentioned abnormality occurs, the multiple propulsion mechanisms 4 can be stopped. Therefore, the drone 1 can descend slowly by the parachute 51. Furthermore, the flight of the drone 1 using the multiple propulsion mechanisms 4 can be stopped.

[0074] As a third comparative example, let's consider a case where, in the event of an anomaly, the signal path sent from the flight controller to the propulsion system's drive unit is interrupted. In this case, if the drive unit malfunctions (an anomaly occurs), the propulsion system cannot be stopped.

[0075] On the other hand, according to the drone 1 of this embodiment, even if the drive unit 7 malfunctions, the power supply to all drive units 7 is stopped by interrupting the power path R2, thus stopping the operation of all drive units 7. Therefore, according to the drone 1, all propulsion mechanisms 4 can be stopped.

[0076] As a fourth comparative example, we will describe a configuration in which the power circuit between the drive unit and the propulsion mechanism is shut off when an abnormality occurs. In this case, in order to stop all propulsion mechanisms, one shut-off device is required for each propulsion mechanism (i.e., the number of drive units). Furthermore, if all the shut-off devices fail to operate, at least one propulsion mechanism will continue to operate.

[0077] On the other hand, according to the drone 1 of this embodiment, only one power path R2 needs to be interrupted, so only one interruption device 11 is required. For this reason, the cost can be reduced compared to the fourth comparative example. Furthermore, if we compare the probability of one interruption device 11 in this embodiment failing over a certain period with the probability of any one of the multiple interruption devices shown in the fourth comparative example failing, the latter is higher because there are more interruption devices. Therefore, according to the drone 1, the probability of a situation occurring where one of the propulsion mechanisms continues to operate in the event of an abnormality can be reduced compared to the fourth comparative example which requires multiple interruption devices.

[0078] (2) The drone 1 is equipped with a trigger device 14 that activates the shut-off device 11 and the ejection device 5 when the above-predetermined abnormality occurs. The trigger device 14 causes the shut-off device 11 to cut off the power supply to the distributor 12 via the power path R2, and then, when predetermined conditions are met, causes the ejection device 5 to eject the parachute 51.

[0079] With this configuration, the power supply to all drive units 7 can be stopped before the parachute 51 is launched from the launch device 5. Therefore, the operation of all propulsion mechanisms 4 can be stopped before the parachute 51 is launched from the launch device 5. Consequently, with the drone 1, the probability of the parachute 51 becoming entangled in the propulsion mechanism 4 can be reduced compared to a configuration in which the parachute 51 is deployed while the propulsion mechanism 4 is operating.

[0080] (3) Based on the occurrence of the predetermined abnormality described above, the flight controller 8 transmits information about the current location of the drone 1 to the ground device 900 using the LTE module 62. With this configuration, if an abnormality occurs in the drone 1, the ground device 900 can find out the current location of the drone 1.

[0081] (4) The drone 1 is equipped with a sensor 15 that detects whether or not the launch device 5 is operating. When the above-described predetermined abnormality occurs, the flight controller 8 uses the LTE module 62 to notify the ground device 900 of the result detected by the sensor 15. With this configuration, when an abnormality occurs in the drone 1, the ground device 900 can find out whether or not the drone 1 has opened the parachute 51.

[0082] (5) The cutoff device 11 is installed between the power module 10 and the distributor 12, and includes a transistor 111A (Fig. 4) that allows current to flow from the power module 10 to the distributor 12 through the power path R2 when in the on state. When the above-mentioned predetermined abnormality occurs in the drone 1, the transistor 111A is turned off. According to such a configuration, the power supply from the power module 10 to the distributor 12 can be stopped. Therefore, the driving of all the propulsion mechanisms 4 can be stopped.

[0083] (6) Each propulsion mechanism 4 includes a propeller 四十ー and a motor 42 that rotates the propeller 41. Each driving device 7 drives the motor 42.

[0084] <E. Modified Example> (1) A first modified example of the cutoff device 11 will be described. Fig. 6 is a diagram showing the state of the power path R2 before cutoff in the first modified example of the cutoff device. Fig. 7 is a diagram showing the state of the power path R2 after cutoff in the first modified example of the cutoff device.

[0085] As shown in Fig. 6, the drone 1 includes a cutoff device 11A instead of the cutoff device 11. The cutoff device 11A includes an igniter 150, a cutting chamber 160 having an internal space, and a rupture plate 163 that is damaged and cracked by the heat and pressure generated by the operation of the igniter 150 and cuts the power path R2. When the above-mentioned abnormality occurs in the drone 1, the trigger device 14 transmits a predetermined signal (command) to the cutoff device 11A, thereby driving the igniter 150.

[0086] The igniter 150 generates a flame and includes an ignition part 151 that contains an ignition charge (not shown) that ignites and burns during operation to generate a flame and a resistor (not shown) for igniting the ignition charge, and a pair of terminal pins 152 connected to the ignition part 151.

[0087] When an abnormality is detected in drone 1, a command is received from the trigger device 14, and a predetermined amount of current flows through the resistor via a pair of terminal pins 152. The flow of current through the resistor generates Joule heat, causing the igniter to start burning. The high-temperature flame produced by the combustion causes the squib cup (not shown) containing the igniter to burst.

[0088] Through-holes 161 are provided in the peripheral wall of the cutting chamber 160, and through-holes 162 are provided in other parts of the peripheral wall. The power path R2 is bridged through these through-holes 161 and 162. The power path R2 is a busbar. The power path R2 is made of, for example, a metal plate or metal wire. One end of the power path R2 is connected to the power module 10, and the other end is connected to the distributor 12.

[0089] When an abnormality is detected in drone 1, a command from the trigger device 14 supplies a predetermined amount of current to the pair of terminal pins 152 of the igniter 150. As shown in Figure 7, the heat and pressure generated by the operation of the ignition unit 151 damage the rupture disc 163. In this case, the rupture disc 163 is damaged such that its central portion splits open and bends toward the power path R2. The power path R2 (more specifically, the busbar) is severed by the damaged rupture disc 163.

[0090] This process allows the power supply from the battery 9 to all drive units 7 via the distributor 12 to be stopped. Therefore, the operation of all propulsion mechanisms 4 can be stopped.

[0091] Instead of cutting the busbar with the rupture disc 163 as described above, the busbar may be cut by an actuator. For example, the busbar may be cut by moving a piston with gas pressure. Alternatively, instead of such cutting, a fuse may be installed on the electrical circuit and blown by passing a current greater than the rated current through the fuse. Even with such a configuration, the drive of all propulsion mechanisms 4 can be stopped in the same manner as described above.

[0092] (2) Figure 8 is a diagram illustrating a second modification of the circuit breaker 11. As shown in Figure 8, the drone 1 is equipped with a circuit breaker 11B instead of the circuit breaker 11. The circuit breaker 11B is equipped with a relay switch 111B. The relay switch 111B includes a coil 171, a movable contact 172, and a fixed contact 173.

[0093] In the relay switch 111B, when current is passed through the coil 171, the movable contact 172 makes contact with the fixed contact 173. That is, the relay switch 111B is turned ON. When the current is stopped from flowing through the coil 171, the movable contact 172 separates from the fixed contact 173, and the relay switch 111B is turned OFF.

[0094] In this configuration, current is supplied to coil 171 when the above-mentioned abnormality does not occur. If an abnormality occurs, the current to coil 171 is stopped. By performing this control, the same effect as when transistor 111A is used can be obtained. Note that a contactor (electromagnetic contactor) may be used instead of relay switch 111B.

[0095] (3) It is preferable that the battery 9 is removable. If the battery 9 is low in charge, the drone 1 can be flown without waiting for charging by removing the battery 9 and installing a fully charged battery. This makes it possible to operate the drone 1 efficiently.

[0096] (4) In the above description, a configuration in which the communication unit 6 receives power from the battery 9 via the power path R1 was used as an example. However, the configuration is not limited to this.

[0097] Figure 9 is a block diagram illustrating the hardware configuration of Drone 1A, a modified version of Drone 1. As shown in Figure 9, in this modified version, the communication unit 6 receives power from the power module 10 via the power path R3, rather than from the flight controller 8 via the battery 9.

[0098] Thus, in this modified example, the power module 10 supplies power from the battery 9 to the flight controller 8 via power path R1, to the distributor 12 via power path R2, and to the GNSS receiver 61, wireless module 62, and LTE module 63 via power path R3. Even with this configuration, the same effect as the drone 1 can be obtained by the shut-off device 11 cutting off the power supply from the power module 10 to the distributor 12 via power path R2 when a predetermined abnormality occurs.

[0099] (5) In the above description, a configuration in which power is supplied from battery 9 to the communication unit 6 was used as an example, but the explanation is not limited to this. Drone 1 and Drone 1A may also be further equipped with other batteries (not shown) and configured to supply power to the communication unit 6 (specifically, the GNSS receiver 61, wireless module 62, and LTE module 63) from these other batteries.

[0100] [Note] The battery includes a first battery (corresponding to battery 9) and a second battery (corresponding to the other batteries mentioned above), and the power module 10 supplies power from the first battery to the flight controller via a first power path and to the distributor via a second power path, and supplies power from the second battery to the communication device and the receiver via a third power path, in the aircraft.

[0101] The embodiments disclosed herein are illustrative and not limited to those described herein. The scope of the present invention is indicated by the claims, and all modifications within the meaning and scope of the claims are intended to be included. [Explanation of Symbols]

[0102] 1,1A Drone, 2 Main body, 3 Arm, 3A,3B,3C,3D Arm, 4A,4B,4C,4D Propulsion mechanism, 5 Launching device, 6 Communication unit, 7A,7B,7C,7D Drive unit, 8 Flight controller, 9,13 Battery, 10 Power module, 11,11A,11B Cut-off device, 12 Distributor, 14 Trigger device, 15,142 Sensor, 18 Support member, 41 Propeller, 42 Motor, 51 Parachute, 61 GNSS receiver, 62 Wireless module, 63 LTE module, 71,81,141 MCU, 72 Current driver, 82 Inertial measurement device, 83 Barometric altimeter, 111 Current switch, 111A Transistor, 111B Relay switch, 150 Ignition device, 151 Ignition unit, 152 Terminal pin, 160 Cutting chamber, 161, 162 through hole, 163 rupture disc, 171, 422 coil, 172 movable contact, 173 fixed contact, 421 magnet, 811 attitude estimation unit, 812 determination unit, 900 ground equipment, 901 remote controller, 902 ground control station, R1, R2 power path.

Claims

1. It is an flying object, Battery and Multiple propulsion mechanisms, A communication device for wireless communication with external devices, A receiver that obtains the current position of the aircraft by receiving radio waves transmitted from multiple positioning satellites, A flight controller that controls the flight of the aircraft and can transmit information about its current position using the communication device, Each of the multiple drive units is connected to the flight controller in a communication manner, and each of the multiple drive units drives different propulsion mechanisms from the multiple propulsion mechanisms, A power distributor is provided to each of the aforementioned multiple drive devices, A power supply module that supplies power from the battery to the communication device, the receiver, and the flight controller via a first power path, and to the distributor via a second power path, An aircraft comprising a shut-off device that, in the event of a predetermined abnormality occurring in the aircraft, shuts off the supply of power from the power module to the distributor via the second power path.

2. The flying object according to claim 1, further comprising a parachute and an ejection device for ejecting the parachute in the event of the predetermined abnormality.

3. The system further includes a trigger device that activates the shut-off device and the injection device when the aforementioned predetermined abnormality occurs. The flying body according to claim 2, wherein the trigger device causes the cutoff device to cut off the supply of power to the distributor via the second power path, and then, when a predetermined condition is met, causes the launching device to launch the parachute.

4. The aircraft according to any one of claims 1 to 3, wherein the flight controller transmits information of the current position to the external device using the communication device based on the occurrence of the predetermined abnormality.

5. The system further includes a sensor for detecting whether or not the injection device is operating, The aircraft according to claim 2 or 3, wherein the flight controller, when the predetermined abnormality occurs, uses the communication device to notify the external device of the result detected by the sensor.

6. The aforementioned circuit breaker device is It includes a transistor installed between the power supply module and the distributor, and which, when in the ON state, supplies current from the power supply module to the distributor via the second power path. The flying body according to any one of claims 1 to 3, wherein the transistor is turned off when the aforementioned predetermined abnormality occurs.

7. The aforementioned aircraft is an unmanned aerial vehicle, Each of the propulsion mechanisms includes a propeller and a motor that rotates the propeller. Each of the aforementioned drive devices drives the motor, the aircraft according to any one of claims 1 to 3.

8. A method for controlling an aircraft, The aircraft supplies power from its built-in battery to a flight controller that controls the aircraft's flight, a communication device for wireless communication with external devices, and a receiver that calculates the aircraft's current position via a first power path, and also supplies power to a distributor that distributes power to each of the multiple drive units via a second power path, and each of the drive units drives different propulsion mechanisms from among the multiple propulsion mechanisms based on commands from the flight controller. If a predetermined abnormality occurs in the aircraft, the step of interrupting the supply of power to the distributor via the second power path, A method for controlling an aircraft, comprising the step of transmitting information of the current position to an external device using the communication device when the aforementioned predetermined abnormality occurs.

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