Unmanned aerial vehicle

Abstract

An unmanned aerial vehicle (100) includes a microphone (103) having a plurality of elements (131), and a processor (101) that processes signals output from the plurality of elements (131). The processor (101) performs detection processing for detecting a target sound signal of a target sound from the output signals, and changes the element that is the target of the processed signals among the plurality of elements (131) in accordance with the result of the detection processing.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an unmanned aerial vehicle. BACKGROUND

[0002] Patent Literature 1 discloses an unmanned aerial vehicle that performs a process of removing background noise from sound data collected by a background microphone.

[0003] (Prior Art Documents)

[0004] (Patent Literature)

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2017-502568 SUMMARY

[0006] Problems to be Solved by the Invention

[0007] Such an unmanned aerial vehicle has difficulty in mounting a large-capacity battery, and thus needs to reduce the amount of electric power required for processing of the unmanned aerial vehicle.

[0008] Therefore, the present disclosure provides an unmanned aerial vehicle capable of simultaneously achieving reduction in electric power consumption of the unmanned aerial vehicle and detection of a target sound.

[0009] Means for Solving the Problems

[0010] The unmanned aerial vehicle according to the present disclosure includes a microphone having a plurality of elements, and a processor that processes a signal output from a target element among the plurality of elements, and performs a detection process of detecting a target sound signal of a target sound from the signal output from the target element among the plurality of elements, and changes the target element among the plurality of elements that outputs the signal to be processed, according to a result of the detection process.

[0011] Another aspect of the present disclosure relates to an unmanned aerial vehicle including a microphone having a plurality of elements, and a processor that processes a signal output from a target element among the plurality of elements, and obtains a flight state of the unmanned aerial vehicle, and changes the target element among the plurality of elements that outputs the signal to be processed, according to the flight state.

[0012] Furthermore, the above-described aspects and specific examples thereof can also be realized by a system, a method, an integrated circuit, a computer program, or a recording medium such as a CD-ROM, and any combination of the system, the method, the integrated circuit, the computer program, and the recording medium.

[0013] Effects of the Invention

[0014] The unmanned aerial vehicle according to the present disclosure can simultaneously achieve reduction in electric power consumption of the unmanned aerial vehicle and detection of a target sound. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram showing the appearance of the unmanned aerial vehicle and the controller according to the first embodiment.

[0016] Figure 2 This is a top view of the unmanned aerial vehicle involved in embodiment 1.

[0017] Figure 3 This is a block diagram showing the structure of the unmanned aerial vehicle according to the first embodiment.

[0018] Figure 4 This is a diagram for explaining an example of a process of changing an element that processes a plurality of signals.

[0019] Figure 5 It is a diagram showing the positional relationship between the unmanned aerial vehicle and the sound source in the first scene when viewed from the horizontal direction.

[0020] Figure 6 This is a diagram showing an example of the element selected as the target element in the first scene.

[0021] Figure 7 It is a diagram showing the positional relationship between the unmanned aerial vehicle and the sound source in the second scene when viewed from the horizontal direction.

[0022] Figure 8 This is a diagram showing an example of the element selected as the target element in the second scene.

[0023] Figure 9 This is a diagram showing another example of the element selected as the target element in the second scene.

[0024] Figure 10 This is a diagram showing an example of the element selected as the target element in the third scene.

[0025] Figure 11 This figure shows an example of elements selected as targets when detecting a target sound in the low power mode.

[0026] Figure 12 This is a flowchart showing an example of the operation of collecting sound of an unmanned aerial vehicle.

[0027] Figure 13 This is a diagram for explaining a first example of processing of a component to be changed according to the remaining battery level.

[0028] Figure 14 This is a diagram for explaining a second example of processing of a component to be changed according to the remaining battery level.

[0029] Figure 15is a diagram for explaining a third example of a process of changing elements that are the objects according to the battery remaining amount.

[0030] Figure 16 is a flowchart showing a first example of the operation of sound pickup of the unmanned flight body according to Embodiment 2.

[0031] Figure 17 is a flowchart showing a second example of the operation of sound pickup of the unmanned flight body according to Embodiment 2.

[0032] Figure 18 is a flowchart showing a third example of the operation of sound pickup of the unmanned flight body according to Embodiment 2.

[0033] Figure 19 is a graph showing the relationship between the noise level of the unmanned flight body and the number of instructions of the number of rotations of the rotating wing.

[0034] Figure 20 is a graph showing one example of the relationship between the number of instructions of the number of rotations of the rotating wing of the unmanned flight body and the number of elements of the object.

[0035] Figure 21 is a flowchart showing one example of the operation of sound pickup of the unmanned flight body according to Embodiment 3.

[0036] Figure 22 is a flowchart showing one example of the change process according to the modification example. DETAILED DESCRIPTION

[0037] (Knowledge on which the present disclosure is based)

[0038] The unmanned aerial vehicle described in Patent Literature 1, as described above, performs signal processing of removing background noise generated from a propulsion unit such as a rotating wing possessed by the unmanned aerial vehicle from collected sound data. However, there is no consideration of selecting elements that become the objects of signal processing from a plurality of elements of a plurality of microphones possessed by the unmanned aerial vehicle. Therefore, according to the unmanned aerial vehicle of Patent Literature 1, there is a possibility that the amount of power required for detection processing of signals output from a plurality of elements cannot be sufficiently reduced.

[0039] An unmanned aerial vehicle has a battery, and drives a plurality of rotary wings using electric power of the battery to obtain a flight thrust. Therefore, a flight time (or a flight distance) of the unmanned aerial vehicle is limited by a time (or a distance) corresponding to an electric storage capacity of the battery. Also, the unmanned aerial vehicle performs the above-described signal processing using the electric power of the battery, and therefore, if electric power is consumed in the signal processing, electric power that can be used for flight of the unmanned aerial vehicle also decreases. Therefore, a flight time of the unmanned aerial vehicle thereafter becomes shorter. Then, it can be considered that the signal processing is stopped in order to suppress a decrease in the flight time, thereby reducing electric power consumption. However, during a period in which the signal processing is stopped, detection of a target sound by a microphone cannot be performed.

[0040] Thus, in the conventional unmanned flight body, it is difficult to simultaneously achieve reduction in electric power consumption of the unmanned flight body and detection of a target sound.

[0041] To solve such a problem, one aspect of the present disclosure relates to an unmanned flight body including a microphone having a plurality of elements, and a processor that processes a signal output from a target element among the plurality of elements, the processor performing a detection process of a target sound signal that detects a target sound from the signal output from the target element among the plurality of elements, and changing the target element among the plurality of elements that outputs the signal to be processed in accordance with a result of the detection process.

[0042] Accordingly, the element to be processed is changed in accordance with a detection result of the target sound signal, and therefore, at least one of before and after the change, the detection process of the signal output from a part of the elements is not performed. Therefore, it is possible to reduce a processing load required for the detection process of at least one of before and after the change, and it is possible to reduce an amount of electric power required for the detection process. Therefore, it is possible to simultaneously achieve reduction in electric power consumption of the unmanned flight body and detection of a target sound.

[0043] Also, the processor can increase the number of the target elements that process the signal in a case where the target sound signal is detected from the signal by the detection process.

[0044] Therefore, it is possible to make the number of the elements to be targeted until the target sound signal is detected smaller than the number of the elements to be targeted after the target sound signal is detected. Therefore, it is possible to continue the detection of the target sound while reducing an amount of electric power required for the signal processing of the signal output from the microphone. Also, after the target sound signal is detected, the number of the elements to be targeted is increased, and therefore, it is possible to improve a quality of a processing result of the signal output from the microphone.

[0045] Another aspect of the present disclosure relates to an unmanned aerial vehicle including a microphone having a plurality of elements, and a processor that processes a signal output from a target element of the plurality of elements, the processor obtaining a flight state of the unmanned aerial vehicle, and changing the target element of the plurality of elements that outputs the signal to be processed in accordance with the flight state.

[0046] Accordingly, the element to be processed is changed in accordance with the flight state of the unmanned aerial vehicle, and thus, detection processing of a signal output from a part of the elements is not performed at least one of before and after the change. Accordingly, it is possible to reduce a processing load required for the detection processing at least one of before and after the change, and it is possible to reduce an amount of power required for the detection.

[0047] Also, the unmanned aerial vehicle can further include a rotary wing for flight, and the flight state can be a number of rotations per unit time of the rotary wing.

[0048] Accordingly, it is possible to select an element suitable for the number of rotations per unit time of the rotary wing as the element to be processed in accordance with the number of rotations per unit time of the rotary wing. Accordingly, it is possible to improve a quality of a processing result of a signal output from the microphone.

[0049] Also, the processor can increase the number of the target elements in the change, and the target elements that output the signal to be processed before the change can include a first element corresponding to a specific direction of the microphone.

[0050] Accordingly, detection processing of a signal output from the first element corresponding to the specific direction of the microphone is performed before the number of the target elements is increased, that is, without detection processing of a signal output from a part of the elements. Accordingly, it is possible to improve a pickup quality of a sound from the specific direction.

[0051] Also, the specific direction can be a direction in which a sound source of a target sound is predicted to exist.

[0052] Accordingly, it is possible to improve a pickup quality of a sound from the sound source.

[0053] Also, the target elements that output the signal to be processed before the change can further include a second element that is closer to a sound source of noise generated by the unmanned aerial vehicle than the first element.

[0054] Accordingly, the first element and the second element are respectively arranged at positions different in distance from a sound source of the noise generated by the unmanned flight body, and thus a time difference in which each element collects the noise is easily generated. Therefore, in the detection processing, the noise generated by the unmanned flight body can be effectively suppressed, and a decrease in pickup quality of the target sound caused by the noise generated by the unmanned flight body can be suppressed. Thus, the pickup quality of the target sound can be improved.

[0055] Also, the object element outputting the signal to be processed before the change can further include a third element located between the first element and the second element.

[0056] Accordingly, the first element, the second element, and the third element are respectively arranged at positions different in distance from a sound source of the noise generated by the unmanned flight body, and thus a time difference in which each element collects the noise is easily generated. Therefore, in the detection processing, the noise generated by the unmanned flight body can be effectively suppressed, and a decrease in pickup quality of the target sound caused by the noise generated by the unmanned flight body can be suppressed. Thus, the pickup quality of the target sound can be improved.

[0057] Also, the processor can further change the object element outputting the signal to be processed among the plurality of elements in the change in accordance with a battery remaining amount of a battery possessed by the unmanned flight body.

[0058] Accordingly, for example, in a case where the battery remaining amount is less than a prescribed threshold value due to flight, detection processing of a signal, or the like, the number of object elements is decreased, and thus the amount of power required for signal processing can be decreased. Therefore, the decrease rate of the battery remaining amount can be decreased, and the flight time of the unmanned flight body can be increased.

[0059] Also, for example, in a case where the battery remaining amount is increased than the prescribed threshold value due to charging or the like, the number of object elements is increased, and thus the pickup quality can be improved.

[0060] Also, the processor can further obtain a flight path of the unmanned flight body, and estimate the battery remaining amount at a position where the unmanned flight body is scheduled to arrive in the flight path.

[0061] Accordingly, the object element can be changed in accordance with the battery remaining amount estimated from the flight path. Thus, for example, in a case where the battery remaining amount is less than a scheduled power consumption amount scheduled to be consumed until the end of flight performed on the flight path, the number of object elements is decreased, and thus the decrease rate of the battery remaining amount can be decreased, and the flight time of the unmanned flight body can be increased. Also, for example, in a case where the battery remaining amount is more than the predicted power consumption amount, the number of object elements is increased compared to a case where the battery remaining amount is less than the predicted power consumption amount, and thus the pickup quality can be improved.

[0062] Also, the processor can estimate a quality of a target sound signal detected using a signal output from the changed object element, and change the flight path in a manner that the quality becomes equal to or greater than a threshold value when the quality is less than the threshold value.

[0063] Accordingly, when the estimated quality of the target sound signal is less than the threshold value, the flight path can be changed in a manner that reduces the flight distance, and the power required for the flight can be used for signal processing. Thus, the number of elements that become targets can be increased, and the quality of the target sound signal can be improved.

[0064] Also, the processor can estimate a quality of a target sound signal detected using a signal output from the changed object element, and increase the number of the object elements in a manner that the quality becomes equal to or greater than a threshold value when the quality is less than the threshold value.

[0065] Accordingly, when the estimated quality of the target sound signal is less than the threshold value, the number of elements that become targets can be increased, and the quality of the target sound signal can be improved.

[0066] Furthermore, the general or specific aspects thereof can be realized by a system, a method, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM, or any combination of the system, the method, the integrated circuit, the computer program, or the recording medium.

[0067] Hereinafter, an unmanned flight body according to one aspect of the present application will be described in detail with reference to the accompanying drawings.

[0068] Furthermore, the embodiments described below each show one specific example of the present application. The numerical values, shapes, materials, component configurations, arrangement positions of components, connection modes, steps, orders of steps, and the like shown in the following embodiments are one example, and are not intended to limit the gist of the present application. Furthermore, components not described in the embodiment showing the most general concept among the components of the following embodiments are described as arbitrary components.

[0069] (Embodiment 1)

[0070] Hereinafter, Embodiment 1 will be described with reference to Figures 1 to 12

[0071] [Structure]

[0072] Figure 1 is a diagram showing the appearance of the unmanned flight body and the controller according to Embodiment 1. Figure 2 is a top view of the unmanned flight body according to Embodiment 1.

[0073] As​Figure 1 and Figure 2 As shown, the unmanned aerial vehicle 100 receives an operation signal corresponding to an operation input (hereinafter, also referred to as "operation") of a user of the controller 200 from the controller 200, and flies in accordance with the received operation signal. Also, the unmanned aerial vehicle 100, in a state of flying, can also perform photographing by the camera 114 provided to the unmanned aerial vehicle 100 in accordance with the received operation signal. The photographed image by the camera 114 can also be transmitted to the controller 200, and can also be transmitted to a portable terminal such as a smartphone.

[0074] The controller 200 receives an operation from a user, and transmits an operation signal corresponding to the received operation to the unmanned aerial vehicle 100. The controller 200 is provided with a display 300. The display 300, for example, displays a photographed image received from the unmanned aerial vehicle 100. Also, the controller 200 can also be connected to a portable terminal such as a smartphone, and thereby use a display of the portable terminal as the display 300.

[0075] Accordingly, the user, while confirming a photographed image photographed by the camera 114 of the unmanned aerial vehicle 100 in real time by the display 300 of the controller 200, operates the controller 200, and thereby can change at least one of a position and a posture of the unmanned aerial vehicle 100 in flight, that is, a flight state. Therefore, the user can freely change a photographing range by the camera 114 of the unmanned aerial vehicle 100.

[0076] The unmanned aerial vehicle 100 is provided with four generators 110, a body 120, and four arms 121.

[0077] Each of the four generators 110 generates a force to make the unmanned aerial vehicle 100 fly. Each of the four generators 110, specifically, generates an airflow, and thereby generates the force to make the unmanned aerial vehicle 100 fly. Each of the four generators 110 has a rotating wing 111 that rotates to generate the airflow, and an actuator 112 that rotates the rotating wing 111. The rotating wing 111 and the actuator 112 have a rotating shaft that is substantially parallel to a vertical direction, and rotate about the rotating shaft to generate an airflow that flows from an upper side of the rotating wing 111 to a lower side. Accordingly, the four generators 110 generate a thrust to make the unmanned aerial vehicle 100 ascend upward, and generate the force to make the unmanned aerial vehicle 100 fly. The actuator 112 is, for example, an electric motor that rotates about the rotating shaft of the rotating wing 111.

[0078] The four generators 110 are respectively arranged at an angle interval of 90 degrees around the body 120 with the center of gravity of the body 120 as a center in a case where the unmanned aerial vehicle 100 is viewed from above. That is, the four generators 110 are arranged in a ring shape around the body 120.

[0079] Moreover, the example in which the four generators 110 each have a rotating wing 111 composed of one propeller is illustrated in the drawing, but the present application is not limited to this, and the rotating wing 111 can also be composed of two propellers that are counter-rotating with respect to each other on the same rotation axis. Furthermore, the number of generators 110 can be less than four, or more than five, as long as the unmanned aerial vehicle 100 can obtain the thrust with which it can fly.

[0080] The body 120 is, for example, a box-shaped member in a substantially cylindrical shape, that is, a housing in which electrical devices such as a processor, a memory, a battery, various sensors, and the like are arranged inside. Moreover, the shape of the body 120 is not limited to a cylindrical shape, and can be another shape such as a quadrangular column.

[0081] Moreover, the camera 114 and the microphone 103 are arranged outside the body 120. The microphone 103 is, for example, a directional microphone having a plurality of elements 131 that pick up sound. The microphone 103 is fixed to the front end of the arm portion 122 that extends in a direction between two generators 110 that are adjacent to each other among the four generators 110 arranged in a ring shape around the body 120, when the unmanned aerial vehicle 100 is viewed from above. That is, the microphone 103 is arranged, for example, to face a direction that deviates by 45° from a direction that faces one of the four generators 110, with the body 120 as the center. The arm portion 122 extends, for example, toward the front of the unmanned aerial vehicle 100. Therefore, the microphone 103 is fixed to the body 120 so as to face the front of the unmanned aerial vehicle 100.

[0082] Moreover, the four arm portions 121 are members that extend from the body 120 toward the four generators 110, and the four generators 110 are fixed to the front ends of the four arm portions 121. That is, one end of each of the four arm portions 121 is fixed to the body 120, and the other end of each of the four arm portions 121 is fixed to one of the four generators 110.

[0083] Figure 3 is a block diagram illustrating the structure of the unmanned aerial vehicle according to Embodiment 1. Specifically, Figure 3 is a block diagram for explaining the hardware structure of the unmanned aerial vehicle 100 and the functions of the processor 101.

[0084] The unmanned aerial vehicle 100 includes a processor 101, a memory 102, a microphone 103, a geomagnetic sensor 104, an acceleration sensor 105, a gyro sensor 106, a GPS (Global Positioning System) receiver 107, a battery 108, a battery monitor 109, a generator 110, a communication IF (Interface) 113, a camera 114, and a gimbal 115.

[0085] The processor 101 obtains detection results detected by various sensors including a microphone 103, a geomagnetic sensor 104, an acceleration sensor 105, a gyro sensor 106, a GPS receiver 107, an image sensor possessed by a camera 114, and the like, a reception result by the communication IF 113, and the like, and executes various processes on the obtained detection results or reception result by executing a prescribed program stored in the memory 102 or a memory not shown in the figure. The processor 101, for example, executes a detection process for detecting a target sound signal of a target sound from signals output from a plurality of elements 131 of the microphone 103. According to this, the processor 101 controls at least one of the four generators 110, the microphone 103, the camera 114, and the communication IF 113.

[0086] The memory 102 stores a coefficient for executing a suppression process for suppressing noise from signals output from the plurality of elements 131 of the microphone 103, that is, a coefficient corresponding to a combination of elements that become an object of the execution of the suppression process, and the like. The memory 102 can also store all of the signals output from the plurality of elements 131 of the microphone 103. The memory 102 can also store a program executed by the processor 101. The memory 102, for example, is realized by a nonvolatile memory.

[0087] The microphone 103 is constituted by a microphone array having a plurality of elements 131 that respectively perform sound pickup. The shape of the microphone 103 is, for example, spherical, and the plurality of elements 131 are arranged at a prescribed interval substantially uniformly on the surface of the spherical microphone 103. According to this, the microphone 103 is able to collect sound from a plurality of directions in a radial direction with respect to the center of the microphone 103. In other words, the microphone 103 is able to collect sound from different plurality of directions around the microphone 103. Moreover, the shape of the microphone 103 is not limited to spherical, and can also be disc-shaped, and the plurality of elements 131 can also be arranged at a prescribed interval on the surface of the disc-shaped microphone 103. The number of the plurality of elements 131 can be, for example, four, eight, 16, or a number other than these.

[0088] The geomagnetic sensor 104 is a sensor that detects a direction of a direction orientation that becomes a reference of the unmanned flight body 100. The direction that becomes the reference can be, for example, the front of the unmanned flight body 100. The geomagnetic sensor 104 is one example of a posture sensor that detects the posture of the unmanned flight body 100.

[0089] The acceleration sensor 105 is a sensor that detects acceleration applied to each of different three directions of the unmanned flight body 100. The acceleration sensor 105 is one example of a position sensor that detects a position of the unmanned flight body 100. Also, the different three directions can be directions that are orthogonal to each other.

[0090] The gyro sensor 106 is a sensor that detects an angular velocity of rotation around each of three axes that are axes of the different three directions of the unmanned flight body 100. The gyro sensor 106 is one example of a posture sensor that detects a posture of the unmanned flight body 100.

[0091] The GPS receiver 107 receives information indicating a position of the GPS receiver from an artificial satellite including a GPS satellite. That is, the GPS receiver 107 detects a current position of the unmanned flight body 100. Also, the artificial satellite that transmits the information received by the GPS receiver 107 is a satellite corresponding to a GNSS (Global Navigation Satellite System), and is not limited to a GPS satellite. The GPS receiver 107 is one example of a position sensor that detects a position of the unmanned flight body 100.

[0092] The battery 108 supplies power necessary for operation of the electric devices possessed by the unmanned flight body 100, such as the processor 101, the memory 102, the microphone 103, the geomagnetic sensor 104, the acceleration sensor 105, the gyro sensor 106, the GPS receiver 107, the battery monitoring section 109, the generators 110, the communication IF 113, the camera 114, and the gimbal 115, to the electric devices. The battery 108 is, for example, a secondary battery that can perform charging and discharging. The battery 108 can also be detachable with respect to the body 120. The battery 108 is not limited to a secondary battery, and can also be a primary battery that can be exchanged (detached).

[0093] The battery monitoring section 109 is a control circuit that monitors an operating state of the battery 108. The battery monitoring section 109 is, for example, a control circuit that performs control of output control that outputs power accumulated in the battery 108 to the electric devices possessed by the unmanned flight body 100, charging control that receives supply of power from an external power source to charge the battery 108, and the like.

[0094] The four generators 110 have been described above, and thus detailed description is omitted.

[0095] The communication IF 113 is a communication interface that communicates with the controller 200 or a communication terminal. The communication IF 113 includes, for example, a communication interface for receiving a transmission signal from the controller 200. Also, the communication IF 113 may, for example, be a wireless LAN (Local Area Network) interface that conforms to the IEEE 802.11a, b, g, n, ac, ax standards, or a Bluetooth (registered trademark) standard-compliant interface. Also, the communication IF 113 can be a communication interface that communicates with the camera 114. The communication IF 113 at this time can be, for example, a wired communication interface using a USB (Universal Serial Bus) or the like.

[0096] The camera 114 is a device that has an optical system such as a lens and an image sensor. The camera 114 is supported by a gimbal 115 that functions to maintain the posture of the camera 114 around three axial directions constant. The gimbal 115 is a device that functions to maintain the posture of the camera 114, for example, a desired posture with respect to a terrestrial coordinate system, even if the posture of the unmanned aerial vehicle 100 changes. Here, the desired posture can be a posture that depends on the photographing direction of the camera 114 included in the operation signal received from the controller 200. Also, the camera 114 can not be supported by the gimbal 115 and can not be fixed in the relative orientation with respect to the body 120.

[0097] The processor 101 has, as functional structures, a flight control section 101a, a prediction section 101b, and a microphone control section 101c. That is, each of the functions of the flight control section 101a, the prediction section 101b, and the microphone control section 101c is implemented by the processor 101 executing a program stored in the memory 102.

[0098] The flight control section 101a controls the number of rotations (i.e., the rotation speed) of the actuators 112 of the generator 110 per unit time in accordance with the current position, the flight speed, and the flight posture of the unmanned aerial vehicle 100 detected by the geomagnetic sensor 104, the acceleration sensor 105, the gyro sensor 106, the GPS receiver 107, and the like, and the operation signal from the controller 200 received by the communication IF 113. Accordingly, the flight control section 101a controls the flight state of the unmanned aerial vehicle 100. That is, the flight control section 101a controls the flight state of the unmanned aerial vehicle 100 in correspondence with the operation signal output from the controller 200 in accordance with the operation of the controller 200 by the user.

[0099] The prediction unit 101b obtains power storage information indicating the battery remaining capacity of the battery 108 from the battery monitoring unit 109, and predicts the remaining flight time in which the UAV 100 can fly, based on the battery remaining capacity indicated by the power storage information. The prediction unit 101b, for example, predicts the flight time in accordance with the battery remaining capacity, the power consumption amount of the generator 110 of the UAV 100, and the power consumption amount of the processor 101. The prediction unit 101b can also measure the power consumption amount of the generator 110 and the power consumption amount of the processor 101 in advance, and predict the flight time using the measurement results.

[0100] The microphone control unit 101c obtains, from each of the plurality of elements 131 of the microphone 103, a signal output by each of the plurality of elements 131 detecting a sound. The microphone control unit 101c obtains a plurality of signals corresponding to the plurality of elements 131, respectively, from the plurality of elements 131. Further, the microphone control unit 101c performs a detection process for detecting a target sound signal of a target sound from the plurality of obtained signals. The microphone control unit 101c changes the element of the plurality of elements 131, which is a target of processing the plurality of signals, in accordance with the result of the detection process. The microphone control unit 101c can also perform, in the detection process, for example, signal conversion for converting a digital signal of the plurality of signals into an analog signal.

[0101] Figure 4 is a diagram for illustrating one example of a process of changing the element of which the plurality of signals are processed.

[0102] As illustrated in the diagram, the microphone control unit 101c switches between a low-power mode and a full processing mode to perform the detection process. In the low-power mode, the microphone control unit 101c sets a part of the plurality of elements 131 of the microphone 103 as a target of the detection process, sets the other part of the elements as a non-target of the detection process, and performs the detection process. In this way, in the low-power mode, the signal output by the part of the plurality of elements 131 of the microphone 103 is used for the detection process, and the signal output by the other part of the elements is not used for the detection process. In the full processing mode, the microphone control unit 101c uses the plurality of signals output by all of the plurality of elements 131 of the microphone 103 for the detection process.

[0103] That is, in the low-power mode, the signal output by the other part of the elements is not used for the detection process, and thus the processing load required for the detection process is reduced compared to the full processing mode. Therefore, in the low-power mode, the power consumption amount can be reduced compared to the full processing mode. On the other hand, in the full processing mode, the signal output by all of the plurality of elements 131 is used for the detection process, and thus the quality of the detected target sound can be improved compared to the low-power mode.

[0104] The microphone control section 101c can also switch from the low-power mode to the full processing mode to increase the number of elements that are the targets of the processing of the signals, for example, in a case where the target sound signal is detected by the detection processing. The microphone control section 101c can also determine that the target sound signal is detected in a case where a sound in a prescribed frequency band is detected by the detection processing. The sound in the prescribed frequency band is, for example, a sound in a range of 300 to 11000 Hz of a frequency band of a human voice, that is, a voice. Accordingly, the microphone control section 101c performs the detection processing in the low-power mode during a period in which the target sound signal is not detected, and thus can reduce the amount of power consumption during the period in which the target sound signal is not detected. Also, the microphone control section 101c switches from the low-power mode to the full processing mode in a case where the target sound signal is detected, and thus can improve the quality of the target sound obtained by the detection processing.

[0105] Also, on the contrary, the microphone control section 101c can also switch from the full processing mode to the low-power mode to reduce the number of elements that are the targets of the processing of the signals, for example, in a case where the target sound signal is detected by the detection processing. Accordingly, the microphone control section 101c can perform the detection of the target sound with high sensitivity, and thus can reduce the time required for the detection of the target sound. Thus, the microphone control section 101c can reduce the amount of power consumption required for the detection processing of the target sound. Also, the detection processing is performed using signals of all the elements, and thus the microphone control section 101c can estimate the position of the sound source of the target sound with high accuracy. Thus, the microphone control section 101c can select the elements that are the targets of the elements in accordance with the estimated position of the sound source of the target sound. Thus, even in the low-power mode, the microphone control section 101c can effectively improve the quality of the target sound obtained.

[0106] Figure 5 and Figure 6 is a diagram illustrating one example of the elements that are the targets of the elements in the first scene in the low-power mode. Figure 5 is a diagram illustrating the positional relationship between the unmanned aerial vehicle and the sound source in the first scene when viewed from the horizontal direction. Figure 6 is a diagram illustrating one example of the elements that are the targets of the elements in the first scene.

[0107] The microphone control section 101c selects, as the elements that are the targets of the detection processing, the first elements that correspond to a specific direction from among the microphones 103. Specifically, the microphone control section 101c can estimate the direction in which the sound pressure of the target sound is large as the specific direction by performing processing on a plurality of signals output from the plurality of elements 131 by a direction estimation algorithm.

[0108] Furthermore, instead of estimating a specific direction based on the detection results of microphone 103, microphone control unit 101c may also estimate the direction based on an image captured by the image sensor of camera 114. In this case, microphone control unit 101c identifies the color, shape, type, etc. of a predetermined sound source through image processing of the captured image, thereby determining the location of the sound source within the image. Furthermore, microphone control unit 101c estimates the direction of the sound source relative to UAV 100 as a specific direction based on the position and posture of camera 114 relative to UAV 100 at the time the image was captured, as well as the location of the sound source within the image.

[0109] Furthermore, the microphone control unit 101c may specify a specific direction based on an operation signal received from the controller 200 via the communication IF 113. In this case, the operation signal includes information indicating the specific direction.

[0110] Furthermore, the sound source may be, for example, a person, an animal, a speaker, or a vehicle.

[0111] The first scene is, Figure 5 The figure shows a scene in which the unmanned aerial vehicle 100 is located above the head of a person serving as the sound source 10. In the first scene, the microphone control unit 101c selects the element 131a located in the direction D1 diagonally downward outward from the unmanned aerial vehicle 100, i.e., in the position on the surface of the microphone 103, on the side of the direction D1 where the sound source 10 is expected to be located, as the first element.

[0112] Furthermore, microphone control unit 101c selects a second element closer to the source of the noise generated by the UAV 100 than element 131a as the element to be detected. For example, microphone control unit 101c selects element 131b, which is closer to generator 110, the source of the noise generated by the UAV 100, as the second element. Furthermore, microphone control unit 101c may select elements 131c and 131d located between elements 131a and 131b as the third element.

[0113] In the first scene, the microphone control section 101c performs the detection processing on the signal output from the element 131a corresponding to the specific direction Dl of the microphone 103. Therefore, it is possible to improve the pickup quality of the sound from the specific direction Dl. Also, in the first scene, the elements 131a, 131b, 131c, 131d of the plurality of elements 131 of the microphone 103 are respectively arranged at positions different in distance from the sound source of the noise generated by the unmanned flight body 100, that is, the generator 110. Therefore, a time difference in which the noise generated by the generator 110 is easily collected occurs in each of the elements 131a, 131b, 131c, 131d. Therefore, in the detection processing, it is possible to effectively suppress the noise generated by the unmanned flight body 100 and to suppress the reduction in the pickup quality of the target sound caused by the noise generated by the unmanned flight body 100. Therefore, it is possible to improve the pickup quality of the target sound.

[0114] Figure 7 and Figure 8 is a diagram showing one example of the element of the element selected as the target in the second scene. Figure 7 is a diagram showing the positional relationship between the unmanned flight body and the sound source in the second scene when viewed from the horizontal direction. Figure 8 is a diagram showing one example of the element of the element selected as the target in the second scene.

[0115] The second scene is, for example, Figure 7 shows a scene in which the unmanned flight body 100 is located at the same height as the sound source 10. The microphone control section 101c selects, in the second scene, the element 131e located in the position of the surface of the microphone 103 in the direction D2 on the side of the position in which the sound source 10 is predicted to exist from the outside of the horizontal direction of the unmanned flight body 100 as the first element.

[0116] Also, the microphone control section 101c selects, as the element to be the target of the detection processing, a second element closer to the sound source of the noise generated by the unmanned flight body 100 than the element 131e. The microphone control section 101c, for example, selects the element 131b closer to the generator 110, which is the sound source of the noise generated by the unmanned flight body 100, as the second element. Also, the microphone control section 101c can select the elements 131f, 131g located between the element 131e and the element 131b as third elements.

[0117] In the second scene, the microphone control section 101c performs the detection processing on the signal output from the element 131e corresponding to the specific direction D2 of the microphone 103. Therefore, it is possible to improve the pickup quality of the sound from the specific direction D2. Also, in the second scene, the elements 131b, 131e, 131f, 131g of the plurality of elements 131 of the microphone 103 are respectively arranged at positions different in distance from the sound source of the noise generated by the unmanned flight body 100, that is, the generator 110. Therefore, in each of the elements 131b, 131e, 131f, 131g, it is easy to generate a time difference in collecting the noise generated by the generator 110. Therefore, in the detection processing, it is possible to effectively suppress the noise generated by the unmanned flight body 100 and to suppress the reduction in the pickup quality of the target sound caused by the noise generated by the unmanned flight body 100. Therefore, it is possible to improve the pickup quality of the target sound.

[0118] Also, the low power mode is not limited to Figures 5 to 8 the example described above, but can also select Figures 9 to 11 the element shown in FIG. 9.

[0119] Figure 9 is a diagram showing another example of the element selected as the object in the second scene. In this case, the microphone control section 101c can select, unlike the case of FIG. 8, the elements 131c, 131h arranged at positions close to a straight line extending in the direction D2 passing through the element 131e, among the other elements than the element 131e as the first element and the element 131b as the second element. Figure 8

[0120] Figure 10 is a diagram showing an example of the element selected as the object in the third scene. The third scene is a scene in which the microphone 103 of the unmanned flight body 100 is located directly above the sound source 10. In this case, the microphone control section 101c selects the element 131g located at a position on the surface of the microphone 103 on the side of the direction D3 in which the sound source 10 is predicted to exist as the first element.

[0121] Also, the microphone control section 101c can select the element 131b closer to the sound source of the noise generated by the unmanned flight body 100 than the element 131g as the second element. Also, the microphone control section 101c can select, among the other elements than the element 131g as the first element and the element 131b as the second element, the elements 131c, 131d arranged at positions close to a straight line extending in the direction D3 passing through the element 131g.

[0122] Figure 11 ​is a diagram showing one example of elements selected as the elements targeted for detection of the sound of interest in the low-power mode. The microphone control section 101c can also select, in the low-power mode at the time of switching from the low-power mode to the full processing mode upon detection of the sound signal of interest by the detection processing, elements located in different directions from each other, for example, as the elements targeted for detection. Figure 11 The selection of elements as the elements targeted for detection is shown. Specifically, the microphone control section 101c can also select elements located at dispersed positions as the elements targeted for detection in such a manner that the elements targeted for detection include elements other than the elements targeted for detection, that is, in such a manner that the elements targeted for detection do not adjoin each other. According to this, even in the case where a small number of elements are set as the elements targeted for detection, the sound of interest can be detected efficiently.

[0123] [Operation]

[0124] Next, the operation of the unmanned aerial vehicle 100 will be described.

[0125] Figure 12 is a flowchart showing one example of the operation of the sound pickup by the unmanned aerial vehicle 100.

[0126] The unmanned aerial vehicle 100 performs sound pickup by the microphone 103 (S11).

[0127] Next, the processor 101 determines whether the processing mode of the present sound pickup is the low-power mode (S12). The processor 101 specifically refers to the mode information showing the processing mode of the present sound pickup stored in the storage 102, and thereby determines whether the processing mode of the sound pickup stored in the storage 102 is the low-power mode.

[0128] The processor 101, in the case where it is determined that the processing mode of the present sound pickup is the low-power mode (YES in S12), performs predetermined processing on the signals output from the elements selected in the low-power mode among all the elements 131 of the microphone 103 (S13). The processor 101, as the predetermined processing, for example, performs processing for suppressing the noise generated from the generator 110 of the unmanned aerial vehicle 100 by using a plurality of signals output from a plurality of elements selected as the elements targeted for detection processing. The number of elements selected as the elements targeted for detection processing in the low-power mode is not limited to a plurality, but can also be one.

[0129] Next, the processor 101 detects the sound of interest by using the processing result of the predetermined processing of step S13 (S14). The processor 101, for example, detects the sound signal of interest showing the sound of interest in a predetermined frequency band from the processed signal obtained by the noise suppression processing.

[0130] Next, the processor 101 determines whether or not the sound pickup event is detected (S15). The processor 101 can determine that the sound pickup event is detected, for example, in a case where the sound pressure level of the target sound signal detected in step S14 is equal to or higher than a predetermined sound pressure level. Also, the processor 101 can determine that the sound pickup event is detected, for example, in a case where the sound pressure level of a specific frequency domain of the target sound signal detected in step S14 is equal to or higher than a predetermined sound pressure level. Also, the processor 101 can determine that the sound pickup event is detected, for example, in a case where the sound recognition of the target sound signal is performed and a predetermined instruction is included in the sound recognition result.

[0131] The processor 101 determines whether or not the object event is detected (S16) in a case where it is determined that the sound pickup event is not detected (NO in S15). The processor 101 can determine that the object event is detected, for example, in a case where the GPS receiver 107 of the unmanned aerial vehicle 100 detects that the unmanned aerial vehicle 100 is located at a position within a predetermined area. Also, the processor 101 can determine that the object event is detected, for example, in a case where the operation signal received by the communication IF 113 from the controller 200 includes information indicating the start of the object event. Also, the processor 101 can determine that the object event is detected, for example, in a case where the image captured by the camera 114 is subjected to image processing and a person is detected in the image.

[0132] The processor 101 switches the processing mode of the sound pickup to the full processing mode (S17) in a case where it is determined that the sound pickup event is detected (YES in S15) or in a case where it is determined that the object event is detected (YES in S16). The processor 101, for example, updates the mode information stored in the memory 102 to information indicating that the processing mode of the sound pickup at present is the full processing mode in a case where the full processing mode is switched.

[0133] Also, in the description, the determination of step S15 and the determination of step S16 are separately performed, but can be performed with the same determination. The processor 101, for example, determines whether or not an event is detected in a case where the same determination is performed. Here, the detection of the event includes the detection of the sound pickup event and the detection of the object event.

[0134] Next, the processor 101 performs a predetermined process on the signals output from all the elements 131 of the microphone 103 (S18). The processor 101, as the predetermined process, for example, performs a process of suppressing the noise generated from the generator 110 of the unmanned aerial vehicle 100 using a plurality of signals output from all the elements 131. Also, the processor 101 performs step S18 also in a case where the processing mode of the sound pickup at present is determined to be the full processing mode in step S12 (NO in S12).

[0135] Next, the processor 101 detects the target sound (S19) using the processing result of the prescribed processing of step S18. The processor 101, for example, detects a target sound signal that shows the target sound in the prescribed frequency band from the processed signal obtained by the processing of suppressing the noise.

[0136] Next, the processor 101 determines whether the full processing mode is completed (S20). The processor 101, for example, determines that the full processing mode is completed in a case where the operation signal received by the communication IF 113 from the controller 200 shows the completion of the full processing mode. Also, the processor 101, for example, determines that the full processing mode is completed in a case where a prescribed time elapses after the target sound is not detected. Also, the processor 101, for example, determines that the full processing mode is completed in a case where the GPS receiver 107 detects that the unmanned aerial vehicle 100 is located at a position outside the prescribed area.

[0137] The processor 101 switches the processing mode of the sound pickup to the low-power mode in a case where it is determined that the full processing mode is completed (YES in S20). The processor 101, for example, updates the mode information stored in the memory 102 to information showing that the processing mode of the sound pickup at present is the low-power mode in a case where it is switched to the low-power mode.

[0138] The processor 101 returns to step S11 in a case where it is determined that the object event is not detected in step S16 (NO in S16), in a case where it is determined that the full processing mode is not completed in step S20 (NO in S20), or in a case where the switching to the low-power mode is completed in step S21, and executes step S11.

[0139] Also, the processor 101 can stop the operation of the sound pickup of the unmanned aerial vehicle 100 in a case where the operation signal received by the communication IF 113 from the controller 200 shows the operation stop.

[0140] [Effects and the like]

[0141] According to the unmanned aerial vehicle 100 related to the present embodiment, the processor 101 executes the detection processing for detecting the target sound signal from the signals output from the plurality of elements 131 of the microphone 103, and changes the element that is the object of the processing signal among the plurality of elements 131 according to the result of the detection processing. That is, the processor 101 changes the element that is the object of the processing according to the detection result of the target sound signal, and thus does not perform the detection processing on the signal output from a part of the elements at least on one of before and after the change. Therefore, it is possible to reduce the processing load required for the detection processing at least on one of before and after the change, and it is possible to reduce the amount of power required for the detection processing.

[0142] (Embodiment 2)

[0143] Embodiment 2 is explained.

[0144] In the unmanned aerial vehicle 100 related to Embodiment 1, the processor 101 changes the element of the plurality of elements 131 of the microphone 103 to which the processing signal is applied, according to the result of the detection processing, but is not limited thereto. In the unmanned aerial vehicle 100 related to Embodiment 2, the processor 101 obtains the battery remaining amount of the battery 108 provided in the unmanned aerial vehicle 100, and changes the element of the plurality of elements 131 of the microphone 103 to which the processing signal is applied, according to the battery remaining amount.

[0145] In this case, the communication IF 113 of the unmanned aerial vehicle 100 obtains the flight path of the unmanned aerial vehicle 100, for example, from the controller 200 or another device. The flight control section 101a estimates the battery remaining amount at the position of the unmanned aerial vehicle 100 predicted to arrive in the flight path, based on the flight path obtained by the communication IF 113 and the battery remaining amount obtained by the prediction section 101b.

[0146] Hereinafter, the processing of changing the element of the plurality of elements 131 of the microphone 103 to which the processing signal is applied according to the battery remaining amount is explained. Figures 13 to 15

[0147] Figure 13 is a diagram for explaining a first example of the processing of changing the element to be applied according to the battery remaining amount. Figure 14 is a diagram for explaining a second example of the processing of changing the element to be applied according to the battery remaining amount. Figure 15 is a diagram for explaining a third example of the processing of changing the element to be applied according to the battery remaining amount.

[0148] As Figures 13 to 15 is shown, the flight path of the unmanned aerial vehicle 100 is, for example, a flight path that departs from the position of the starting point H1, passes through the waypoints P1, P2, P3, and P4 in this order, and returns to the starting point H1.

[0149] As Figure 13 is shown, the first example is an example in which the unmanned aerial vehicle 100 performs the processing of picking up sound in the full processing mode in the entire flight path. In the unmanned aerial vehicle 100, the flight control section 101a predicts the battery consumption amount, the battery remaining amount, the battery remaining amount prediction at the time of arrival at the starting point H1, the sound pickup processing mode, and the battery remaining amount until the starting point H1 for each of the waypoints P1 to P4 of the flight path.

[0150] ​The battery consumption amount shows the amount of power consumed from the starting point H1 to each of the waypoints P1 to P4. For example, the battery consumption amount is the proportion of the amount of power consumed from the starting point H1 to each of the waypoints P1 to P4, with respect to the battery capacity. The power consumption amount is, for example, able to be obtained by time-integrating the change in the time series of the output current of the battery 108 over the operation period of the unmanned flight body 100, multiplying the value obtained by the time integration by the rated voltage of the battery 108. The change in the time series of the output current is able to be obtained by sequentially measuring the output current from the battery 108.

[0151] The battery remaining amount shows the remaining amount of the battery 108 from the starting point H1 to each of the waypoints P1 to P4. For example, the battery remaining amount is the value obtained by subtracting the battery consumption amount from 100%.

[0152] The battery remaining amount prediction at the arrival at the starting point H1 is the prediction of the battery remaining amount remaining when the unmanned flight body 100 flies while picking up sound from each of the waypoints P1 to P4 to the starting point H1. The battery remaining amount prediction is the value obtained by subtracting, from the battery remaining amount of each of the waypoints P1 to P4, the proportion of the amount of power consumed until the arrival at the starting point H1 with respect to the battery capacity. The amount of power predicted to be consumed is, for example, able to be obtained by obtaining past flight data including the change in the flight state, the flight distance, and the power consumption amount corresponding to the change in the flight state and the flight distance from each of the waypoints P1 to P4 to the starting point H1, and calculating the average power consumption amount from the obtained past flight data. Also, the change in the flight state is, for example, the change in the flight speed, the change in the forward flight, the rotary flight, or the change in the rotation speed of the rotary wing 111 of each of the generators 110.

[0153] The sound pickup processing mode is the same as the processing mode explained in Embodiment 1.

[0154] The battery remaining amount to the starting point H1 is information showing the prediction of whether there is a battery remaining amount at the arrival at the starting point H1. The battery remaining amount to the starting point H1 becomes "yes" when the battery remaining amount prediction is a positive number, and becomes "no" when the battery remaining amount prediction is a negative number.

[0155] In the first example, the battery remaining amount of all of the waypoints P1 to P4 becomes "yes", and therefore, the unmanned flight body 100 is able to fly while picking up sound over the entire flight path even in a state where the full processing mode is maintained without becoming the low-power mode.

[0156] As Figure 14The second example is shown as an example in which the unmanned aerial vehicle 100 flies while picking up sound on the flight path as in the first example, but in which the power of the battery 108 consumed in the middle of the flight is more than in the first example due to the influence of unexpected wind or flight to confirm the source of a suspicious sound detected. Also, the second example is an example in which sound is picked up in the entire flight path in the full processing mode as in the first example.

[0157] In the second example, the power of the battery 108 consumed up to the waypoint P2 is more than in the first example, and therefore, the battery remaining amount at the time of reaching the starting point H1 at the waypoint P2 is predicted to be negative. That is, the battery consumption amount up to the starting point H1 is larger than the battery remaining amount in the state of maintaining the full processing mode, and therefore, it is predicted that the unmanned aerial vehicle 100 cannot reach the starting point H1.

[0158] Therefore, it is possible to switch the processing mode of picking up sound from the full processing mode to the low-power mode, and thereby increase the flight time of the unmanned aerial vehicle 100.

[0159] As Figure 15 The third example is shown as an example in which the power of the battery 108 consumed in the middle of the flight is more than in the first example due to the influence of unexpected wind or flight to confirm the source of a suspicious sound detected as in the second example. Also, the third example is an example in which the processing of picking up sound is performed by switching from the full processing mode to the low-power mode, unlike the first example and the second example.

[0160] In the third example, as in the second example, the power of the battery 108 consumed up to the waypoint P2 is more than in the first example, and therefore, the battery remaining amount at the time of reaching the starting point H1 at the waypoint P2 is predicted to be negative, and it is predicted that the unmanned aerial vehicle 100 cannot reach the starting point H1 in the state of maintaining the full processing mode. Then, the unmanned aerial vehicle 100 switches the processing mode of picking up sound from the full processing mode to the low-power mode. Accordingly, the battery remaining amount at the time of reaching the starting point H1 after the waypoint P3 is predicted to be positive, and it is predicted that the unmanned aerial vehicle 100 can fly while picking up sound up to the starting point H1.

[0161] Figure 16 is a flowchart showing a first example of the operation of picking up sound by the unmanned aerial vehicle 100 according to Embodiment 2.

[0162] The unmanned aerial vehicle 100 picks up sound using the microphone 103 (S31).

[0163] Next, the processor 101 predicts the power consumption amount for flying along the flight path (S32). The processor 101, for example, multiplies the flight time required for flying from the current position to the starting point H1 via the respective waypoints P1 to P4 of the flight path by the average of the power consumption amount per unit time of the processing mode of the sound pickup at present, thereby calculating the power consumption amount required for the sound pickup during the return to the starting point H1. Also, the processor 101, for example, calculates the power consumption amount required for flying from the current position to the starting point H1 via the respective waypoints P1 to P4 of the flight path. The processor 101 adds the power consumption amount required for the sound pickup during the return to the starting point H1 to the power consumption amount required for the sound pickup during the return to the starting point H1, thereby calculating the predicted power consumption amount predicted to be consumed until the flight along the flight path ends. The processor 101 calculates the battery consumption amount until the starting point H1 using the calculated power consumption amount.

[0164] Next, the processor 101 determines whether there is power consumed in the processing mode at present in the battery 108 (S33). The processor 101, for example, determines whether the battery consumption amount for flying along the flight path calculated in step S32 is smaller than the battery remaining amount of the battery 108. The processor 101 determines that there is power consumed in the processing mode at present in the battery 108 in the case where the battery consumption amount is smaller than the battery remaining amount, and otherwise determines that there is no power consumed in the processing mode at present in the battery 108.

[0165] The processor 101, in the case where it is determined that there is no power consumed in the processing mode at present in the battery 108 (NO in S33), reduces the number of elements that are the objects of the sound pickup processing in the plurality of elements 131 of the microphone 103, and performs the sound pickup processing (S34). The processor 101, for example, switches from the full processing mode to the low-power mode, thereby reducing the number of elements that are the objects.

[0166] Also, the processor 101, after reducing the number of elements that are the objects of the sound pickup processing, again determines whether there is power consumed in the processing mode at present in the battery 108 (S35).

[0167] The processor 101, in the case where it is determined that there is no power consumed in the processing mode at present in the battery 108 (NO in S35), returns to step S34 in order to further reduce the number of elements that are the objects of the sound pickup processing in the plurality of elements 131 of the microphone 103.

[0168] The processor 101, in the case where it is determined that there is power consumed in the processing mode at present in the battery 108 in step S33 or step S35 (YES in S33 or S35), returns to step S31.

[0169] Also, the unmanned flight body 100 according to Embodiment 2 can perform, Figure 17 the work of sound pickup.

[0170] Figure 17 is a flowchart showing a second example of the work of sound pickup of the unmanned flight body 100 according to Embodiment 2.

[0171] The unmanned flight body 100 performs sound pickup using the microphone 103 (S41).

[0172] Next, the processor 101 estimates the power consumption for flight along the flight path (S42). Specifically, the processor 101 performs the same processing as in step S32.

[0173] Next, the processor 101 determines whether or not there is power consumed in the present processing mode in the battery 108 (S43). Specifically, the processor 101 performs the same processing as in step S33.

[0174] The processor 101, in a case where it is determined that there is no power consumed in the present processing mode in the battery 108 (NO in S43), reduces the number of elements that are the objects of sound pickup processing among the plurality of elements 131 of the microphone 103, and performs sound pickup processing (S44). The processor 101, for example, switches from the full processing mode to the low-power mode, thereby reducing the number of objects.

[0175] Next, the processor 101 estimates the SNR (Signal-Noise Ratio) of the target sound obtained as a result of the sound pickup processing, and determines whether or not the estimated SNR is greater than a threshold value (S45). Also, the SNR of the target sound is one example of an index that shows the quality of the target sound. The SNR of the target sound is, for example, the difference between the sound pressure level of the signal obtained by the microphone 103 collecting the sound generated by the flight of the unmanned flight body 100 before the noise suppression processing and the sound pressure level of the target sound obtained by the microphone 103 collecting the target sound after the noise suppression processing.

[0176] The processor 101, in a case where it is determined that the SNR of the target sound obtained as a result of the sound pickup processing is equal to or less than the threshold value (NO in S45), restores the number of objects to the original number, and performs sound pickup processing (S46).

[0177] Next, the processor 101 adjusts the flight path of the unmanned flight body 100 (S47). The processor 101, for example, changes the distance of the flight path to be short.

[0178] The processor 101, in a case where it is determined that the SNR of the target sound obtained as a result of the sound pickup processing is greater than the threshold value ("Yes" in S45), determines whether or not there is power consumed in the current processing mode in the battery 108 (S48). Specifically, the processor 101 performs the same processing as in step S43.

[0179] The processor 101, in a case where it is determined that there is no power consumed in the current processing mode in the battery 108 ("No" in S48), adjusts the flight path of the unmanned aerial vehicle 100 (S49). The processor 101, for example, changes the distance of the flight path to be short.

[0180] The processor 101, in a case where it is determined that there is power consumed in the current processing mode in the battery 108 ("Yes" in S43 or S48), returns to step S41 after step S47 or after step S49.

[0181] Also, the unmanned aerial vehicle 100 according to Embodiment 2 can perform Figure 18 the sound pickup operation.

[0182] Figure 18 is a flowchart illustrating a third example of the sound pickup operation of the unmanned aerial vehicle 100 according to Embodiment 2.

[0183] The unmanned aerial vehicle 100 performs sound pickup using the microphone 103 (S51).

[0184] Next, the processor 101 predicts the amount of power consumption for flying along the flight path (S52). Specifically, the processor 101 performs the same processing as in step S32.

[0185] Next, the processor 101 determines whether or not there is power consumed in the current processing mode in the battery 108 (S53). Specifically, the processor 101 performs the same processing as in step S33.

[0186] The processor 101, in a case where it is determined that there is no power consumed in the current processing mode in the battery 108 ("No" in S53), reduces the number of elements that are the targets of the sound pickup processing in the plurality of elements 131 of the microphone 103, and performs the sound pickup processing (S54). The processor 101, for example, switches from the full processing mode to the low-power mode, thereby reducing the number of target elements.

[0187] Next, the processor 101 determines whether or not the SNR of the target sound obtained as a result of the sound pickup processing is greater than the threshold value (S55).

[0188] The processor 101, in a case where it is determined that the SNR of the target sound obtained as a result of the sound pickup processing is below the threshold value (NO in S55), adjusts the flight path of the unmanned flight body 100 (S56). The processor 101, for example, changes the distance of the flight path to be short.

[0189] The processor 101, in a case where it is determined that there is consumed power in the battery 108 in the current processing mode (YES in S53), determines whether there is consumed power in the battery 108 even if the element that is the object of the sound pickup processing is increased (S57).

[0190] The processor 101, in a case where it is determined that there is consumed power in the battery 108 even if the element that is the object of the sound pickup processing is increased (YES in S57), increases the number of elements that are the object of the sound pickup processing in the plurality of elements 131 of the microphone 103, and performs the sound pickup processing (S58). The processor 101, for example, switches from the low-power mode to the full processing mode, thereby increasing the number of the object elements.

[0191] The processor 101, in a case where it is determined that the SNR of the target sound obtained as a result of the sound pickup processing is larger than the threshold value (YES in S55), determines whether there is consumed power in the battery 108 in the current processing mode (S59). Specifically, the processor 101 performs the same processing as in step S53.

[0192] The processor 101, in a case where it is determined that there is no consumed power in the battery 108 in the current processing mode (NO in S59), adjusts the flight path of the unmanned flight body 100 (S60). The processor 101, for example, changes the distance of the flight path to be short.

[0193] The processor 101, after step S56, after step S58, after step S60, in a case where it is determined in step S57 that there is no consumed power in the battery 108 even if the element that is the object of the sound pickup processing is increased (NO in S57), or in a case where it is determined in step S59 that there is consumed power in the battery 108 in the current processing mode (YES in S59), returns to step S51.

[0194] [Effects and the like]

[0195] According to the unmanned flight body 100 and the like according to the present embodiment, the processor 101 reduces the number of elements that are the targets in a case where it is determined that there is no power consumed in the present processing mode in the battery 108, and thus, it is possible to reduce the amount of power required for signal processing. Therefore, it is possible to reduce the reduction speed of the battery level, and it is possible to increase the flight time of the unmanned flight body. Also, for example, in a case where the battery level is increased more than a prescribed threshold value by charging or the like, the number of elements that are the targets is increased, and thus, it is possible to improve the pickup quality.

[0196] Also, according to the unmanned flight body 100 according to the present embodiment, the processor 101 further estimates the battery level at positions where the unmanned flight body 100 is scheduled to arrive in the flight path, that is, the respective waypoints P1 to P4.

[0197] Therefore, the processor 101 can change the elements that are the targets in accordance with the battery level estimated from the flight path. For example, the processor 101 reduces the number of elements that are the targets in a case where the battery level is greater than a predicted power consumption amount predicted to be consumed until the flight along the flight path ends in the present processing mode, and thus, it is possible to reduce the reduction speed of the battery level, and it is possible to increase the flight time of the unmanned flight body 100. Also, for example, in a case where the battery level is greater than the predicted power consumption amount, the number of elements that are the targets is made greater than in a case where the battery level is less than the predicted power consumption amount, and thus, it is possible to improve the pickup quality.

[0198] Also, according to the unmanned flight body 100 according to the present embodiment, in a case where the estimated SNR of the target sound signal is less than a threshold value, it is possible to use, for signal processing, power required for flight that is reduced by changing the flight path in such a way that the flight distance is shortened. Therefore, it is possible to increase the number of elements that are the targets, and thus, it is possible to improve the quality of the target sound signal.

[0199] Furthermore, according to the UAV 100 of this embodiment, the processor 101 estimates the SNR of the target sound signal detected using the signal output from the target element after the target element has been modified. If the estimated SNR is less than a threshold, the number of target elements is increased so that the SNR exceeds the threshold. For example, if the determination in step S45 is "No," the number of target elements is restored to the original number in step S46, thereby increasing the number of target elements. This can improve the SNR. Furthermore, if the determination in step S55 is "No," the flight path is shortened, reducing the predicted power consumption calculated the next time step S52 is performed, making it easier to determine "Yes" in step S53. Furthermore, if the determination in step S53 is "Yes," the number of target elements is increased in step S58 for sound collection processing if the determination in step S57 is "Yes," thereby improving the SNR. In this way, increasing the number of target elements when the estimated SNR of the target sound signal is less than the threshold can improve the quality of the target sound signal.

[0200] (Implementation 3)

[0201] Implementation method 3 will be described.

[0202] In the UAV 100 according to Embodiment 3, the processor 101 obtains the flight state of the UAV 100 and changes the element whose signal is processed among the plurality of elements 131 of the microphone 103 according to the flight state. The flight state is, for example, the number of rotations per unit time of the rotor 111 of the generator 110 of the UAV 100.

[0203] Figure 19 This is a graph showing the relationship between the noise level of an unmanned aerial vehicle and the rotation speed command of the rotor blades.

[0204] As shown in the figure, the greater the rotation speed command for rotor blade 111 and the greater the number of rotations per unit time of rotor blade 111, the higher the noise level generated by UAV 100. This is because the noise generated by UAV 100 is primarily generated by the rotation of rotor blade 111. Therefore, processor 101 may increase the number of elements 131 of microphone 103 that are subject to sound collection processing as the noise level generated by UAV 100 increases, thereby improving the quality of the target sound obtained through sound collection processing.

[0205] Figure 20 This is a diagram showing an example of the relationship between a rotation speed command of a rotor blade of an unmanned aerial vehicle and the number of target elements.

[0206] Processor 101 can also refer to Figure 20The illustrated relationship changes the object element in accordance with the number-of-rotations instruction of the rotating wing 111 of the flight of the unmanned flight body 100. The processor 101 changes the object element in a manner that the number of the object element increases as the number-of-rotations instruction increases. Also, the number-of-rotations instruction is illustrated, for example, by a ratio of the number of rotations of the rotating wing 111 per unit time that is required for obtaining the thrust of the flight, with respect to the maximum number of rotations of the rotating wing 111 per unit time.

[0207] Figure 21 is a flowchart illustrating one example of the operation of the sound pickup of the unmanned flight body 100 according to Embodiment 3.

[0208] In the unmanned flight body 100, sound is picked up using the microphone 103 (S71).

[0209] Next, the processor 101 obtains the number-of-rotations instruction (S72). The processor 101 specifically determines the number of rotations of the rotating wing 111 per unit time as the number of rotations for causing the generator 110 to generate the thrust of the flight indicated by the operation of the controller 200 or the flight of the flight path. The processor 101 outputs the number-of-rotations instruction for driving the rotating wing 111 at the determined number of rotations per unit time to the generator 110.

[0210] The processor 101 selects the output number-of-rotations instruction so that the number of rotations of the rotating wing 111 per unit time is Figure 20 The illustrated relationship corresponds to the combination of the object elements (S73). The processor 101 selects the object element of Set B, for example, in the case where the number-of-rotations instruction is 55%.

[0211] The processor 101 performs the noise suppression process using the selected combination of the object elements (S74).

[0212] [Effects and the like]

[0213] According to the unmanned flight body 100 according to the present embodiment, the object element of the process is changed in accordance with the flight state of the unmanned flight body 100, such as the number of rotations of the rotating wing per unit time, and thus the detection process on the signal output from a part of the elements is not performed at least one of before and after the change. Therefore, it is possible to reduce the processing load required for the detection process at least one of before and after the change, and it is possible to reduce the amount of power required for the detection process. Also, it is possible to select the element suitable for the number of rotations of the rotating wing per unit time as the object element of the process in accordance with the number of rotations of the rotating wing per unit time. Therefore, it is possible to improve the quality of the processing result of the signal output from the microphone.

[0214] (Modified example)

[0215] The change process of the changed object element of the described embodiment can also Figure 22The flowchart illustrates the processing of the change. The change processing can be applied to, for example, the processing illustrated in steps S21, S34, S44, S46, S54, S58, S73, and the like.

[0216] Figure 22 The flowchart illustrates one example of the change processing involved in the modification example.

[0217] The processor 101, if the change processing is started, judges whether or not the processing coefficient of the combination of the elements of the object is stored by the memory 102 (S81). The processing coefficient is a coefficient corresponding to each element of the combination of the plurality of elements of the object used for the noise suppression processing. The processing coefficient takes a different value depending on the combination of the elements of the object.

[0218] The processor 101, in the case where it is judged that the processing coefficient of the combination of the elements of the object is stored by the memory 102 (YES in S81), obtains the processing coefficient corresponding to the combination of the elements of the object from the memory 102 (S82).

[0219] Next, the processor 101 applies the processing coefficient corresponding to the obtained combination of the elements of the object to the pickup processing, thereby executing the pickup processing (S83). The processor 101, for example, applies the coefficient corresponding to each of the plurality of signals output from the elements of the object in the processing coefficient, thereby executing the pickup processing.

[0220] The processor 101, in the case where it is judged that the processing coefficient of the combination of the elements of the object is not stored by the memory 102 (NO in S81), judges whether or not the sound data for calibration of the entire elements of the microphone 103 is stored by the memory 102 (S84). The sound data for calibration is, for example, data in which white noise is collected.

[0221] The processor 101, in the case where it is judged that the sound data for calibration of the entire elements of the microphone 103 is stored by the memory 102 (YES in S84), generates the processing coefficient corresponding to the combination of the elements of the object using the sound data (S85).

[0222] The processor 101, in the case where it is judged that the sound data for calibration of the entire elements of the microphone 103 is not stored by the memory 102 (NO in S84), selects the combination of the elements of the object from among the plurality of combinations of the elements corresponding to the plurality of processing coefficients stored by the memory 102 (S86).

[0223] Also, in the embodiment, the processor 101 changes the element of the plurality of elements 131 of the microphone 103 that becomes the object of the pickup processing, but is not limited thereto, and the power supply of the plurality of elements 131 of the microphone 103 can be turned on or off to change the element that becomes the object of the pickup processing.

[0224] Also, in the embodiment, the processor 101 can perform signal processing on the signal output from the plurality of elements 131 of the microphone 103 in real time, and can store the output signal to the memory 102 to perform signal processing using the plurality of signals stored in the memory 102 later. In this case, information showing whether the processing mode of the sound pickup of the plurality of signals stored in the memory 102 is the full processing mode or the low power mode can be stored in the memory 102 together with the signals.

[0225] Also, in the embodiment, the processor 101 changes the element of which processing is the object among the plurality of elements 131 of the microphone 103, but is not limited thereto, and can also adjust the frequency band extracted from the obtained signal. The extracted frequency band can be the frequency band of a human voice, and can be the frequency band of a specific sound such as a flute sound. The processor 101 can reduce the processing load and the amount of power consumption by performing processing of sound pickup after extracting a signal of a frequency band narrower than the output signal.

[0226] Also, in the embodiment, in the case where the number of elements of which adjustment is the object is adjusted, for example, adjustment can be continuously performed in units of one element, or adjustment can be performed in stages in units of a group including a plurality of elements. For example, the number of elements of which adjustment is the object can be adjusted in n stages. That is, the number of elements of which adjustment is the object can be increased or decreased in units of one element, or can be increased or decreased in stages in units of a group including a plurality of elements.

[0227] Also, in each of the embodiments, each of the constituent elements can be constituted by a dedicated hardware, or can be realized by executing a software program suitable for each of the constituent elements. Each of the constituent elements can be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded by a recording medium such as a hard disk or a semiconductor memory.

[0228] The unmanned aerial vehicle according to one or more aspects of the present application has been described above according to the embodiment, but the present application is not limited to the embodiment. As long as the present application is not deviated from the scope thereof, various modified aspects or aspects constituted by combining the constituent elements of different embodiments that a person skilled in the art can think of with respect to the present embodiment can also be included in the scope of one or more aspects of the present application.

[0229] Moreover, the processing by the processor 101 and the image recognition processing and the sound recognition processing can also utilize machine learning. For the machine learning, for example, there can be cited supervised learning that learns the relationship of input and output using teacher data to which a label (output information) is given to input information, unsupervised learning that constructs the structure of data only from input without a label, semi-supervised learning that handles both with and without a label, reinforcement learning that learns a continuous action so that the most reward can be obtained against feedback (reward) of an action selected in accordance with the observation result of the state, and the like. Moreover, as a specific method of the machine learning, there are a neural network (including deep learning using a multi-layered neural network), genetic programming, a decision tree, a Bayesian network, a support vector machine (SVM), and the like. In the present disclosure, any one of the above cited specific examples can be utilized.

[0230] Industrial applicability

[0231] The present disclosure is useful for an unmanned flight body or the like capable of simultaneously achieving reduction of power consumption and detection of a target sound.

[0232] List of symbols

[0233] 10 sound source

[0234] 100 unmanned flight body

[0235] 101 processor

[0236] 101a flight control section

[0237] 101b prediction section

[0238] 101c microphone control section

[0239] 102 memory

[0240] 103 microphone

[0241] 104 geomagnetic sensor

[0242] 105 acceleration sensor

[0243] 106 gyro sensor

[0244] 107 GPS receiver

[0245] 108 battery

[0246] 109 battery monitoring section

[0247] 110 generator

[0248] 111 rotary wing

[0249] 112 actuator

[0250] 113 communication IF

[0251] 114 camera

[0252] 115 gimbal

[0253] 120 body

[0254] 121 arm

[0255] 122 arm portion

[0256] 131 element

[0257] 200 controller

[0258] 300 display

Claims

1. An unmanned aerial vehicle, comprising: a microphone having a plurality of elements, each of the plurality of elements being an element for picking up sound; and a processor for processing a signal output from a target element among the plurality of elements, the processor performing a detection process for detecting a target sound signal from the signal output from the target element among the plurality of elements, and changing the number of the target elements among the plurality of elements that output the signal to be processed according to a result of the detection process, wherein the plurality of elements of the microphone include a first element and a second element, the second element being closer to a sound source of the noise than the first element, and before the change, the target elements that output the signal to be processed include the second element.

2. The unmanned aerial vehicle according to claim 1, wherein the processor increases the number of the target elements that output the signal to be processed when the target sound signal is detected from the signal through the detection processing.

3. The unmanned aerial vehicle according to claim 1 or 2, wherein the processor increases the number of the target elements during the change, and before the change, the target elements that output the signal to be processed also include the first element corresponding to the specific direction of the microphone. 4 . The unmanned aerial vehicle according to claim 3 , wherein the specific direction is a direction in which a sound source of the target sound is predicted to exist. 5 . The unmanned aerial vehicle according to claim 3 , wherein, before the change, the target element that outputs the signal to be processed further includes a third element located between the first element and the second element.

6. The unmanned aerial vehicle according to claim 1 or 2, wherein the processor, in the changing, further changes the number of the target elements that output the signal to be processed among the plurality of elements according to the remaining battery level of a battery included in the unmanned aerial vehicle.

7. The UAV according to claim 6, wherein the processor is further configured to obtain a flight path of the UAV and estimate the remaining battery level at a location within the flight path where the UAV is scheduled to arrive.

8. The unmanned aerial vehicle according to claim 7, wherein the processor estimates the quality of the target sound signal detected using the signal output from the target element after the change, and changes the flight path when the quality is less than a threshold value.

9. The unmanned aerial vehicle according to claim 1 or 2, wherein the processor estimates the quality of the target sound signal detected using the signal output from the changed target element, and when the quality is less than a threshold, increases the number of the target elements in such a manner that the quality becomes greater than the threshold.

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