Unmanned aerial machine system

Abstract

To provide an unmanned aerial machine system which has a simplified wireless power supply mechanism.SOLUTION: A system of an unmanned aerial machine comprises: a light source point including a light source for emitting light from the ground surface, in a state where the light source point is fixed so as to emit the light in a right above direction; and an unmanned aerial machine which has, a light reception part for receiving the light and converting the light into power, a power storage part for storing the power transmitted from the light reception part, a drive part for rotating rotary blades by the power stored in the power storage part, and a control part for controlling the drive part. The control part controls the drive part on the basis of a distribution of the light radiated to the light reception part.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to unmanned aerial systems. [Background technology]

[0002] Unmanned aerial vehicles such as drones are used in a variety of fields. Unmanned aerial vehicles have the advantage of being lightweight and capable of flying for long periods of time with only a small amount of electrical energy.

[0003] One way to extend the flight time of an unmanned aerial vehicle is to increase the capacity of the power storage unit installed in the unmanned aerial vehicle. However, increasing the capacity of the power storage unit increases the weight of the unmanned aerial vehicle, which does not necessarily lead to an extension of the flight time.

[0004] Therefore, a wireless power supply method is known in which electrical energy is converted into light energy from the ground and sent to an unmanned aerial vehicle in flight. Patent Document 1 describes a method of irradiating an unmanned aerial vehicle in flight with infrared light. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-013063 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, there is a need to fly an unmanned aerial vehicle so that it stays in one place at any altitude. The purpose is, for example, to monitor the ground by mounting a surveillance camera on the unmanned aerial vehicle. Normally, the surveillance camera is mounted on a tall structure such as a building to monitor the ground from a high place. However, construction costs and rental costs for the structure are incurred. Also, due to various legal regulations, there are many cases where it is not possible to build a structure to mount a surveillance camera or to rent a structure. However, if a surveillance camera is mounted on an unmanned aerial vehicle, construction costs and rental costs for the structure are not incurred, and there is no need to comply with legal regulations regarding the construction and rental of structures.

[0007] On the other hand, if a surveillance camera is mounted on an unmanned aerial vehicle and surveillance is continued, the flight time will be long. Since the capacity of the power storage unit is limited, the surveillance time is likely to be restricted by the flight time of the unmanned aerial vehicle. If a wireless power supply method such as that described in Patent Document 1 is introduced, such restrictions will be reduced. However, the wireless power supply method of Patent Document 1 requires a complex system that tracks the unmanned aerial vehicle from the ground and emits light toward the unmanned aerial vehicle moving in the air while adjusting the emission direction of the light source. The problem to be solved by the present invention is to provide an unmanned aerial vehicle system with a simplified wireless power supply mechanism. [Means for solving the problem]

[0008] In order to address such problems, the present inventor has devised the following unmanned aerial vehicle system. The present invention relates to an unmanned aerial vehicle system, comprising: a light source point including a light source for emitting light from the ground in a fixed state so as to emit the light in a vertically upward direction; the unmanned aerial vehicle having a light receiving unit that receives the light and converts it into electricity, a power storage unit that stores the electricity sent from the light receiving unit, a drive unit that rotates rotors using the electricity stored in the power storage unit, and a control unit that controls the drive unit; The control unit autonomously controls the drive unit based on a distribution of light irradiated to the light receiving unit.

[0009] In this specification, an unmanned aerial vehicle refers to an aircraft that cannot accommodate a human. An unmanned aerial vehicle flies by remote control using a remote control device, or flies autonomously. An unmanned aerial vehicle can stop in the air (hover). An unmanned aerial vehicle includes a so-called drone. An unmanned aerial vehicle may be a rotorcraft (helicopter or multicopter) that has rotors. A rotorcraft obtains lift and thrust by rotating rotors.

[0010] The unmanned aerial vehicle uses the power stored in the power storage unit to drive a motor and rotate the rotors. The unmanned aerial vehicle receives light emitted from a light source located on the ground at the light receiving unit. The light receiving unit converts the light into electricity and stores the electricity in the power storage unit. In other words, the power storage unit is charged. Since the unmanned aerial vehicle can charge the power storage unit while flying, the number of times the unmanned aerial vehicle takes off and lands can be reduced. The power storage unit is a storage battery or a capacitor.

[0011] As described above, the light source provided at the light source point emits light from the ground in a state where the light is fixed to be emitted directly upward. Here, "a state where the light is fixed to be emitted directly upward" means that the light is emitted almost perpendicular to the horizontal plane. By emitting light almost perpendicular to the horizontal plane, a power supply space whose horizontal position does not change depending on the altitude can be formed in the sky above the light source point. In this specification, "sky" refers to the space vertically above any point and its vicinity.

[0012] When a power supply space whose horizontal position does not change with altitude is formed above the light source point, the unmanned aerial vehicle can ascend without moving laterally while remaining in the power supply space. When an unmanned aerial vehicle takes off, lands, or changes flight altitude, it consumes a large amount of power. In such a situation where power consumption is high, being able to continue receiving power from the light source point without lateral movement makes it easier for the unmanned aerial vehicle to take off, land, or change flight altitude, and makes it possible to reduce the capacity of the storage unit. Reducing the capacity of the storage unit of the unmanned aerial vehicle contributes to making the storage unit lighter and smaller. Furthermore, when light is emitted almost perpendicular to the horizontal plane, the distance between the light source point and the unmanned aerial vehicle can be minimized, and the loss of emitted light in the atmosphere can be minimized.

[0013] During operation of the system, the light source point does not move. Therefore, a power supply space for the unmanned aerial vehicle is fixedly formed in the sky above the light source point. During flight, the unmanned aerial vehicle can enter the fixedly formed power supply space to receive power. Then, the unmanned aerial vehicle can continue to receive power by remaining in the power supply space. Therefore, in the system, a mechanism for the light source to change the direction of light emission and track the unmanned aerial vehicle is not required, and thus the wireless power supply mechanism is simplified.

[0014] The system detects the distribution of light emitted from the light source and irradiated to the light receiving unit. This makes it possible to recognize whether the unmanned aerial vehicle is in a state where it is powered from the power supply space. In addition, the control unit of the unmanned aerial vehicle can obtain relative position information of the unmanned aerial vehicle with respect to the light source location from the distribution of light irradiated to the light receiving unit. The control unit then controls the drive unit based on the calculated relative position. In this way, the unmanned aerial vehicle is controlled autonomously. In this way, since the light receiving unit can be used as one of the positioning mechanisms of the unmanned aerial vehicle, it is possible to omit the installation of other positioning mechanisms or to use the light receiving unit in combination with other positioning mechanisms, thereby achieving cost reduction effects and improving performance. The other positioning mechanisms include, for example, a positioning mechanism using an image sensor, a positioning mechanism using a GPS, a positioning mechanism using an acceleration sensor or an angular velocity sensor, or a compass.

[0015] The control unit may control the driving unit so that the center of the distribution of the light irradiated to the light receiving unit is located at a predetermined position of the light receiving unit. This allows the unmanned aerial vehicle to be positioned in the horizontal direction. Here, the "center of light" may refer to the most luminous point in the luminance distribution of the light projected on a cross section perpendicular to the light traveling direction. Alternatively, the "center of light" may refer to the center of gravity of a figure in a geometric sense when the luminance distribution is viewed as a figure. For example, if the light projected on a cross section perpendicular to the light traveling direction is circular, the "center of light" may be the center of the circle.

[0016] the light is divergent or convergent, The control unit may derive the altitude at which the unmanned aerial vehicle flies from the size of the light irradiated to the light receiving unit, and control the drive unit based on the derived altitude. This allows the unmanned aerial vehicle to be positioned in the vertical direction. Here, the "size of the light" may represent the maximum diameter of the light receiving area on the light receiving unit or the area of ​​the light receiving area. Alternatively, the "size of the light" may be a value determined by the vertical dimension of the light receiving area and the horizontal dimension perpendicular to the vertical dimension.

[0017] the intensity distribution in a cross section perpendicular to the emission direction of the light is non-circular; The control unit may detect the amount of rotation of the light in the light receiving unit and control the yaw angle θz of the unmanned aerial vehicle. When the intensity distribution is noncircular, a feature of the rotation direction can be extracted from the light received by the light receiving unit in a cross section perpendicular to the light traveling direction. Thus, the unmanned aerial vehicle can be positioned in the rotation direction around the Z axis. Light with a noncircular intensity distribution has, for example, a shape in which the vertical dimension of the outer diameter of the intensity distribution of the light projected on a cross section perpendicular to the light traveling direction is different from the horizontal dimension of the outer diameter. Light with a noncircular intensity distribution includes, for example, an ellipse or a square. Also, the intensity distribution may be non-rotationally symmetrical.

[0018] The control unit may detect the amount of change in the shape of the light received by the light receiving unit and control the roll angle θx and pitch angle θy of the unmanned aerial vehicle.

[0019] The light receiving section is divided into a plurality of light receiving regions, Each of the light receiving regions is composed of a plurality of photoelectric conversion elements, The control unit may control the drive unit based on the amount of photoelectromotive force received for each of the light receiving regions.

[0020] the plurality of light receiving regions are composed of four regions, i.e., first to fourth quadrants, which are separated by a first axis and a second axis perpendicular to the first axis; The control unit may control the drive unit so that the center of the light irradiated to the light receiving unit is located at a predetermined position on the light receiving unit at the intersection of the first axis and the second axis.

[0021] The light receiving section may include a plurality of photoelectric conversion elements, and may detect the amount of photoelectromotive force generated by each of the photoelectric conversion elements.

[0022] A beam profile camera may be used to detect a portion of the light passing through the light receiving section, thereby detecting the light receiving state of the light receiving section.

[0023] The unmanned aerial vehicle includes at least one of an angular velocity sensor and an acceleration sensor, The control unit may obtain a signal from the angular velocity sensor or the acceleration sensor.

[0024] The unmanned aerial vehicle may be equipped with an imaging unit for imaging the ground. The control unit of the unmanned aerial vehicle may autonomously control the drive unit based on the image captured by the imaging unit. As described above, the light receiving unit is used as a sensor that acquires relative position information of the unmanned aerial vehicle with respect to the light source point. However, in an abnormal situation such as the light receiving unit losing sight of the light from the light source point, the relative position information of the unmanned aerial vehicle is acquired based on an image captured by an imaging unit that captures the ground, and the unmanned aerial vehicle is moved based on the relative position information. The imaging unit may be shared with an imaging unit used for monitoring purposes.

[0025] The light source point may include an image capture unit. The light source point may send information about the position of the unmanned aerial vehicle obtained from the imaging unit to the unmanned aerial vehicle.

[0026] The light intensity distribution emitted by the light source spot may have a top hat shape.

[0027] The light source point includes a plurality of light sources that emit the light, The light emission shape of each light source may be rectangular or linear. Note that in this specification, the "rectangle" of the light emission shape of each light source (or the entire light source) includes light emission shapes having chamfered corners. Effect of the Invention

[0028] A simplified unmanned aerial vehicle system can be provided. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a conceptual diagram of a monitoring system. [Diagram 2] FIG. 1 is a block diagram of a monitoring system. [Diagram 3] FIG. 1 illustrates an unmanned aerial vehicle in flight. [Figure 4A] 13 is a diagram showing a state in which a part of the light receiving unit does not enter the power supply space. FIG. [Figure 4B] 13 is a diagram showing a state in which the entire light receiving unit is placed in the power supply space. FIG. [Diagram 5] FIG. [Figure 6A] 13 is a diagram showing the amount of photovoltaic power generated when the unmanned aerial vehicle is displaced from its original position. [Figure 6B] 13 is a diagram explaining a method of deriving the direction and amount of movement of an unmanned aerial vehicle from the photovoltaic power in each quadrant. [Figure 7] 13A and 13B are diagrams illustrating modified examples of electrical connections between photoelectric conversion elements and aircraft control units. [Figure 8] FIG. 2 is a diagram showing a state in which light emitted from a light source point is divergent light. [Figure 9A] 13 is a diagram showing the power supply space projected onto the light receiving unit when the unmanned aerial vehicle is at low altitude. FIG. [Figure 9B] 13 is a diagram showing the power supply space projected onto the light receiving unit when the unmanned aerial vehicle is at a high altitude. FIG. [Figure 10] 1 is a diagram showing the unmanned aerial vehicle rotating through a yaw angle θz. [Figure 11A] FIG. 13 is a diagram showing a state where the rotor is rotated by a pitch angle θy. [Figure 11B] 13 is a diagram showing a power supply space projected onto a light receiving unit when rotated by a pitch angle θy. FIG. [Figure 12] 1 is a diagram illustrating a method for measuring the position of an unmanned aerial vehicle using an imaging unit at a light source point. [Figure 13] FIG. 2 is a diagram illustrating an example of an optical system including a light source and light emitted from the light source. [Figure 14] 2 is a diagram showing an emission portion of the light source from which light is emitted, viewed from the emission side toward the light source. FIG. [Figure 15] This is the light intensity distribution of the light emitted from the light source point. [Figure 16] FIG. 13 is a diagram showing a modified example of the unmanned aerial vehicle. [Figure 17] FIG. 4 is a block diagram of an unmanned aircraft system according to a second embodiment. [Figure 18] FIG. 11 is a conceptual diagram of an unmanned aircraft system according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, an embodiment of an unmanned aerial vehicle system will be described with reference to the drawings. Each drawing is a schematic diagram. The dimensional ratio and the number of each component in the drawings do not necessarily correspond to the actual dimensional ratio and the number of each component.

[0031] [Unmanned Aerial Vehicle System Overview] FIG. 1 is a conceptual diagram of an embodiment of an unmanned aircraft system. The unmanned aircraft system of this embodiment is a surveillance system 100 in which an unmanned aircraft 2 is used to monitor the ground. FIG. 1 is a conceptual diagram of the surveillance system 100. FIG. 2 is a block diagram of the surveillance system 100. The surveillance system 100 includes a light source point 1 and an unmanned aircraft 2. The unmanned aircraft 2 can take off from the ground under its own power, and can ascend, descend, move laterally, move diagonally, and stop in the air (hover).

[0032] The unmanned aerial vehicle 2 has an imaging unit 21, a light receiving unit 22, a power storage unit 24, a drive unit 25, an aircraft control unit 26, and a communication unit 27. The imaging unit 21 monitors by capturing images of a monitored area on the ground. The captured images may be sent to the light source point 1 using the communication unit 27, or may be sent to a remote control device 3 of a second embodiment described below. The light source point 1 or the remote control device 3 may analyze the captured images and take some action, such as issuing a warning, as appropriate. The unmanned aerial vehicle 2 itself may analyze the captured images.

[0033] The light receiving unit 22 receives the light energy transmitted from the light source point 1 and converts it into electricity. The electricity is stored in the power storage unit 24. The power from the power storage unit 24 is used to drive the drive unit 25 to rotate the rotor 28 (see FIG. 1). The light receiving unit 22 includes a plurality of photoelectric conversion elements. The communication unit 27 is used to communicate with the light source point 1 or other devices such as the remote control device 3 shown in the second embodiment. A series of operations is controlled by the aircraft control unit 26.

[0034] FIG. 1 illustrates the rotation of the blades of rotor 28, but does not illustrate the shape of the blades of rotor 28. However, the shape and number of blades known for rotorcraft are applied to unmanned aerial vehicle 2. That is, unmanned aerial vehicle 2 has four sets of rotors 28, but the number of sets of rotors 28 is not particularly limited. The number of blades of rotor 28 per set is not particularly limited. Unmanned aerial vehicle 2 remains within power supply space 10 by hovering, and can continue to monitor the ground while charging power storage unit 24.

[0035] The imaging unit 21 has a unique field of view 20 (see FIG. 1). The field of view 20 represents the range that the imaging unit 21 can capture without changing the shooting direction. The higher the flying altitude of the unmanned aerial vehicle 2, the larger the field of view. The imaging unit 21 may be equipped with a zoomable lens so that the imaging unit 21 can capture enlarged images as necessary. Also, by making the orientation of the lens of the imaging unit 21 changeable, the imageable range may be expanded beyond the field of view 20 of the imaging unit 21.

[0036] The imaging unit 21 may be sensitive to at least one of ultraviolet light, visible light, and infrared light. It is desirable that the imaging unit 21 has no sensitivity to the wavelength of light emitted from the light source point 1. The imaging unit 21 may be, for example, a two-dimensional image sensor such as a CCD or CMOS, or a one-dimensional image sensor. The object imaged by the imaging unit 21 may be a video or a still image. The imaging unit 21 may be supported so that the imaging unit 21 maintains its attitude in a fixed direction (for example, horizontally) regardless of the attitude of the unmanned aerial vehicle 2.

[0037] [Light source point] The light source point 1 will be described in detail. The light source point 1 includes a light source 11, a light source control unit 16, a power supply unit 14, a communication unit 17, and an imaging unit 18 (see FIG. 2). The light source control unit 16 controls the turning on and off of the light source 11 and the adjustment of the amount of emitted light.

[0038] As shown in FIG. 1, before the system of the unmanned aerial vehicle 2 is operated, the light source point 1 is fixedly positioned at an arbitrary point. The light emission direction is fixed toward the sky. When each light source 11 is turned on, a fixed light beam is formed from the ground toward the sky. This fixed light beam functions as a power supply space 10 for powering the unmanned aerial vehicle 2. The unmanned aerial vehicle 2 flies so that the mounted light receiving unit 22 enters the power supply space 10, so that the light receiving unit 22 can receive the light emitted from the light source 11. When the light receiving unit 22 receives the light, charging of the power storage unit 24 begins. By keeping the unmanned aerial vehicle 2 within the power supply space 10, charging of the power storage unit 24 can be continued.

[0039] The power supply space 10 refers to a space having a predetermined light intensity or more, centered on the optical axis of the light emitted from the light source 11. The region having a predetermined light intensity or more is, for example, a region through which a light beam having a light intensity of 50% or more of the light intensity of the light beam with the highest light intensity passes among any cross section perpendicular to the emission direction.

[0040] The light source 11 emits light almost perpendicular to the horizontal plane. By emitting light perpendicular to the horizontal plane, a power supply space 10 whose horizontal position does not change depending on the altitude can be formed in the sky above the light source point 1. Then, the unmanned aerial vehicle 2 can rise without moving laterally (horizontally) while remaining in the power supply space 10. In particular, the power consumption when the unmanned aerial vehicle 2 rises is much greater than the power consumption when the unmanned aerial vehicle 2 moves laterally. In such a situation where power consumption is high, being able to continue receiving power supply without moving laterally makes it easier for the unmanned aerial vehicle 2 to take off and change the flight altitude, and also reduces the storage capacity of the power storage unit 24. It is not necessary for the light source 11 to emit light almost perpendicular to the horizontal plane.

[0041] Because the unmanned aerial vehicle 2 can be wirelessly powered, there is no need to previously store the power required from when the unmanned aerial vehicle 2 takes off until it lands in the power storage unit 24. This allows the power storage capacity of the power storage unit 24 of the unmanned aerial vehicle 2 to be reduced, which contributes to making the power storage unit 24 lighter and more compact. Also, because power can be supplied in the air, there is no need for the unmanned aerial vehicle to land for charging. As a result, it can be monitored continuously for a long period of time (for example, one hour or more), reducing the time it is not monitored or eliminating the need to fly a substitute aircraft while it lands and charges.

[0042] The light emitted from the light source 11 includes at least one of infrared light, visible light, and ultraviolet light. The light source 11 is preferably a laser light. Laser light has high directivity and high output, and therefore has excellent power transmission efficiency.

[0043] The light source point 1 may also serve as a takeoff and landing site for the unmanned aerial vehicle 2. The light source point 1 may also have a hangar for the unmanned aerial vehicle 2.

[0044] The power supply unit 14 of the light source point 1 may be connected to a commercial power source, or may be connected to a power generation device or a storage battery. The power generation device may be a power generation device using fossil fuels or the like, or a power generation device using renewable energy such as solar, wind, hydroelectric, geothermal, or biomass.

[0045] [Horizontal position adjustment of unmanned aerial vehicles using a light receiver] Fig. 3 is a diagram showing the unmanned aerial vehicle 2 in flight. Figs. 4A and 4B are diagrams showing the unmanned aerial vehicle 2 as viewed in the +Z direction from the light source point 1 side. However, for the sake of explanation, Figs. 4A and 4B do not show other elements of the unmanned aerial vehicle 2, such as the imaging unit 21, and show the light receiving unit 22 as being located at the center of the unmanned aerial vehicle 2. In Figs. 3, 4A, and 4B, the area 10 hatched with diagonal lines is the area where the power supply space 10 is projected onto the unmanned aerial vehicle 2.

[0046] It is desirable to fly the unmanned aerial vehicle 2 so that the entire light receiving unit 22 is in the power supply space 10. However, the light receiving unit 22 may be displaced from the power supply space 10 or may move away from the power supply space 10 during flight due to the influence of wind or the occurrence of a control response delay time. In FIG. 3 and FIG. 4A, a state in which a part of the light receiving unit 22 is outside the projection area of ​​the power supply space 10 can be seen. This is the result of both the unmanned aerial vehicle 2 shown in FIG. 3 and FIG. 4A being displaced by the D1 vector from the original position. As a result, light is not irradiated to a part of the light receiving unit 22. Note that the original position in this embodiment is a position where the center 10c of the light irradiated to the light receiving unit overlaps with the center 22c of the light receiving unit 22, but depending on the shape of the light receiving unit 22, the center 10c of the light irradiated to the light receiving unit 22 may overlap with a predetermined position other than the center 22c of the light receiving unit 22.

[0047] If light is not irradiated to a portion of light receiving unit 22, the light receiving unit cannot exhibit sufficient power storage capacity. Therefore, as shown in FIG. 4B, it is necessary to move unmanned aerial vehicle 2 so that the entire light receiving unit 22 is within power supply space 10. Based on the distribution of light irradiated to light receiving unit 22, aircraft control unit 26 moves unmanned aerial vehicle 2 so that center 22c of the light receiving unit overlaps center 10c of area 10. The movement of unmanned aerial vehicle 2 is performed by controlling drive unit 25.

[0048] An example of a method for deriving the movement direction and movement amount of the unmanned aerial vehicle 2 to return the unmanned aerial vehicle 2 to its original position based on the distribution of light irradiated to the light receiving unit 22 will be described. FIG. 5 is an enlarged view of only the light receiving unit 22. The light receiving unit 22 includes a plurality of photoelectric conversion elements 41. The plurality of photoelectric conversion elements 41 are each connected to the aircraft control unit 26. A lens 42 is laminated on each of the photoelectric conversion elements 41. Light from the light source point 1 enters the photoelectric conversion element 41 through the lens 42. The photoelectric conversion elements 41 are arranged in alignment in the X direction and the Y direction. If a line X1 passing through the center 22c of the light receiving unit 22 is parallel to the X direction, and a line Y1 passing through the center 22c of the light receiving unit 22 is parallel to the Y direction, the light receiving unit 22 can be divided into four quadrants: a first quadrant Q1, a second quadrant Q2, a third quadrant Q3, and a fourth quadrant Q4. Each photoelectric conversion element 41 belongs to one of the quadrants Q1 to Q4. The light receiving section 22 is designed so that each of the quadrants Q1 to Q4 includes the same number of photoelectric conversion elements 41. In this embodiment, each of the quadrants Q1 to Q4 includes 32 photoelectric conversion elements 41.

[0049] Fig. 6A is a diagram showing the photoelectric conversion state of each photoelectric conversion element 41 when unmanned aerial vehicle 2 is displaced by vector D1 from its original position (position where center 22c of light receiving unit 22 overlaps center 10c of region 10) as in Fig. 4A. In Fig. 6A, photoelectric conversion elements 41 in the hatched region generate a photoelectromotive force exceeding the threshold and contribute sufficiently to charging power storage unit 24. Photoelectric conversion elements 41 in the non-hatched region generate a photoelectromotive force that does not reach the threshold and do not contribute sufficiently to charging power storage unit 24.

[0050] With reference to FIG. 6B, a method of deriving the movement direction and movement amount of the unmanned aerial vehicle 2 from the photovoltaic power of each quadrant will be described. Lines representing the first quadrant Q1 to the fourth quadrant Q4 are extended from the origin, which is the center 22c of the light receiving unit 22. The line representing the first quadrant Q1 is a line on Y=X in the first quadrant Q1. The line representing the second quadrant Q2 is a line on Y=-X in the second quadrant Q2. The line representing the third quadrant Q3 is a line on Y=X in the third quadrant Q3. The line representing the fourth quadrant Q4 is a line on Y=-X in the fourth quadrant Q4. In FIG. 6B, the first quadrant Q1 is shown in the form of Q1(A,B). Here, A represents the number of photoelectric conversion elements 41 whose photovoltaic power amount exceeds the threshold, and B represents the number of photoelectric conversion elements 41 whose photovoltaic power amount does not exceed the threshold. The aircraft control unit 26 counts the number of photoelectric conversion elements 41 whose photovoltaic power amount exceeds the threshold value and the number of photoelectric conversion elements 41 whose photovoltaic power amount does not exceed the threshold value. The same is true for the second quadrant Q2, the third quadrant Q3, and the fourth quadrant Q4.

[0051] A vector quantity is calculated based on the above-mentioned tabulation results regarding the electromotive forces of the photoelectric conversion elements. Vector I (Q1-Q3) is displayed on Y=X based on a vector quantity based on a value obtained by subtracting the number of photoelectric conversion elements 41 that exceed the threshold in the third quadrant Q3 (here, 11) from the number of photoelectric conversion elements 41 that exceed the threshold in the first quadrant Q1 (here, 32). Vector I (Q2-Q4) is displayed based on a vector quantity based on a value obtained by subtracting the number of photoelectric conversion elements 41 that exceed the threshold in the third quadrant Q3 (here, 24) from the number of photoelectric conversion elements 41 that exceed the threshold in the second quadrant Q2 (here, 18). (Q1-Q3) and vector I (Q2-Q4)Vector S is a composite vector of the above. Vector S correlates with the direction and amount of movement required to return the unmanned aerial vehicle 2 to its original position. The correlation coefficient between the vector based on the photoelectric conversion element and the direction and amount of movement of the unmanned aerial vehicle 2 is a specified value that can be calculated in advance. Therefore, the aircraft control unit 26 can derive the direction and amount of movement of the unmanned aerial vehicle 2 from the composite vector S. Then, the aircraft control unit 26 can control each drive unit 25 to achieve the direction and amount of movement of the unmanned aerial vehicle 2.

[0052] The above-mentioned method of deriving the movement direction and movement amount for returning the unmanned aerial vehicle 2 to its original position from the distribution of light irradiated to the light receiving unit 22 is one example, and is not limited to this derivation method. In the above, the light receiving unit 22 is divided into four quadrants, but the light receiving unit 22 may be divided into five or more regions to derive the movement direction and movement amount.

[0053] FIG. 7 shows a modified example of the electrical connection between the photoelectric conversion element 41 and the aircraft control unit 26. In FIG. 7, four photoelectric conversion elements 41 overlapping the same rectangle 43 constitute a group of photoelectric conversion elements. In the group of photoelectric conversion elements, each photoelectric conversion element 41 is electrically connected in series. In this way, the aircraft control unit 26 determines the movement direction and movement amount of the unmanned aerial vehicle 2 for each group of photoelectric conversion elements. Since the aircraft control unit 26 does not need to control each individual photoelectric conversion element 41, the calculation and control of the aircraft control unit 26 are simplified. Here, four photoelectric conversion elements 41 overlapping the same rectangle 43 are grouped as one group, but three or less or five or more photoelectric conversion elements 41 may be grouped as one group. When the light receiving unit 22 is divided into four quadrants, the photoelectric conversion elements 41 included in each quadrant may be grouped as one group of photoelectric conversion elements 41.

[0054] The aircraft control unit 26 repeatedly detects the distribution of light irradiated to the light receiving unit 22, and transmits a signal to and controls the drive of the drive unit 25 of the unmanned aircraft 2 based on the detection result. This allows the unmanned aircraft 2 to fly so that the entire light receiving unit 22 remains in the power supply space 10. The repetition time interval is preferably 1 msec to 1 sec. The shorter the repetition time interval, the more stable it is expected that the state in which the entire light receiving unit 22 remains in the power supply space 10.

[0055] [Characteristics of emitted light] The light emitted from the light source point 1 may be parallel light, divergent light, or convergent light. In the case of parallel light, the light beam emitted from the exit surface of the light source point 1 travels with approximately the same diameter. In the case of divergent light, the diameter of the light beam emitted from the exit surface of the light source point 1 increases as it travels. In the case of convergent light, the diameter of the light beam emitted from the exit surface of the light source point 1 decreases as it travels.

[0056] FIG. 8 shows a case where the light emitted from the light source point 1 is divergent light having a divergence angle θ1. The divergence angle θ1 is the angle θ1 between a straight line parallel to the optical axis of the emitted light and the light beam. Usually, as the altitude of the unmanned aerial vehicle 2 increases and moves away from the light source point 1, it becomes more difficult for the light receiving unit 22 to capture the light emitted from the light source point 1. When the emitted light is divergent light, the power supply space 10 expands in the horizontal direction as the altitude increases. Then, when the emitted light is divergent light, the difficulty of the light receiving unit 22 to capture the light emitted from the light source point 1 is reduced. On the other hand, since the light beam is diffused over a wide range, the light energy density decreases, and the light transmission efficiency to the unmanned aerial vehicle 2 may decrease. When the emitted light is converging light, the advantages and disadvantages of when the emitted light is diverging light are reversed. In other words, when the emitted light is converging light, it becomes more difficult for the light receiving unit 22 to capture the emitted light from the light source point 1, but as the altitude of the unmanned aerial vehicle 2 increases and it moves away from the light source point 1, the light energy density increases, and the decrease in the efficiency of light transmission to the unmanned aerial vehicle 2 is suppressed.

[0057] [UAV altitude adjustment using the light receiver] When the light emitted from the light source point 1 is either divergent light or convergent light, the aircraft control unit 26 can derive the altitude at which the unmanned aerial vehicle flies from the size of the light irradiated to the light receiving unit 22. When the light irradiated to the light receiving unit 22 is rectangular, the altitude may be derived from the vertical and horizontal dimensions of the rectangle. This makes it possible to control the drive unit based on the derived altitude.

[0058] Assume that the light emitted from the light source point 1 is divergent light. FIG. 9A shows the power supply space 10 projected on the light receiving unit 22 in the case of a relatively low altitude. FIG. 9B shows the power supply space 10 projected on the light receiving unit 22 in the case of a relatively high altitude. The power supply space 10 projected on the light receiving unit 22 in FIG. 9B is larger than the power supply space 10 projected on the light receiving unit 22 in FIG. 9A. In this way, when the light emitted from the light source point 1 is divergent light, the power supply space 10 projected on the light receiving unit 22 becomes larger as the altitude increases. Conversely, when the light emitted from the light source point 1 is convergent light, the power supply space 10 projected on the light receiving unit 22 becomes smaller as the altitude increases.

[0059] The relationship between the area of ​​the power supply space 10 projected on the light receiving unit 22 and the altitude of the unmanned aerial vehicle 2 can be clarified by calculation. It is also possible to obtain in advance a data table that associates the altitude measurement results of the unmanned aerial vehicle 2 obtained using other measuring instruments such as surveying equipment with the area of ​​the power supply space 10 projected on the light receiving unit 22. Therefore, the altitude of the unmanned aerial vehicle 2 can be derived from the area of ​​the power supply space 10 projected on the light receiving unit 22 by calculation or by using a data table obtained in advance.

[0060] When the altitude of the unmanned aerial vehicle 2 is derived, the aircraft control unit 26 determines whether the derived altitude matches a pre-set altitude, and if the altitude does not match, the aircraft control unit 26 controls the drive unit 25 so that the altitude becomes the pre-set altitude.

[0061] In this way, the diameter of the power supply space 10 is an important index for controlling the altitude of the unmanned aerial vehicle 2. Therefore, the diameter of the power supply space 10 can be freely set to a desired size. It is preferable to continue to measure and correct the diameter periodically so that the set diameter of the power supply space 10 does not change.

[0062] Specifically, the diameter of the power supply space 10 should be 50 mm or more and 200 mm or less. The range of the light emitted from the light source 11, i.e., the height of the power supply space 10, should be equal to or higher than the maximum flying altitude of the unmanned aerial vehicle 2. For example, if the maximum flying altitude of the unmanned aerial vehicle 2 is set to 150 m, the height of the power supply space 10 should be equal to or higher than 150 m. The preferred altitude for monitoring by the unmanned aerial vehicle 2 is 20 m or more and 150 m or less.

[0063] [Adjusting the rotation direction of an unmanned aerial vehicle using a light receiver] FIG. 10 shows the unmanned aerial vehicle 2 rotated from a reference position by a yaw angle θz in a rotation direction around the Z axis. The unmanned aerial vehicle 2 in flight is in a state in which the light receiving unit 22 has rotated in a rotation direction around the Z axis relative to the power supply space 10 due to the influence of wind or the occurrence of a response delay time of the control. The control unit detects the amount of rotation of the light in the light receiving unit and controls the yaw angle θz of the unmanned aerial vehicle. In FIG. 10, the power supply space 10 projected on the light receiving unit 22 has a rectangular shape (however, the corners have a chamfered shape) with different vertical (Y direction) and horizontal (X direction) dimensions. However, such a shape is not necessarily required. The power supply space 10 projected on the light receiving unit 22 may alternatively be an ellipse shape, or may be a square shape with the same vertical (Y direction) and horizontal (X direction) dimensions. It is preferable that the light intensity distribution in a cross section perpendicular to the light emission direction is noncircular. In addition, even if the light intensity distribution is different rather than the light dimensions, the amount of rotation of the light can be detected.

[0064] FIG. 11A shows a state in which the light receiving unit 22 of the unmanned aerial vehicle 2 has rotated by a pitch angle θy from a reference horizontal position in a rotation direction centered on the Y axis included in the horizontal plane. In FIG. 11A, a square-shaped light is emitted from the light source point 1 in a cross section perpendicular to the emission direction. In FIG. 11A, the unmanned aerial vehicle 2 itself is omitted from the illustration, and only the light receiving unit 22 is shown. During flight, the unmanned aerial vehicle 2 is in a state in which the light receiving unit 22 has rotated in a rotation direction centered on the Y axis relative to the power supply space 10 due to the influence of wind or the occurrence of a response delay time of control. The control unit detects the amount of rotation of the light in the light receiving unit and controls the pitch angle θy of the unmanned aerial vehicle. With respect to the power supply space 10, the light in a cross section perpendicular to the emission direction of the light is a square shape with chamfered corners.

[0065] 11B shows the power supply space 10 projected on the light receiving unit 22 when rotated by a pitch angle θy from a reference horizontal position. Since the unmanned aerial vehicle 2 is tilted by a pitch angle θy with respect to the power supply space 10 formed in the sky from the light source point 1, the power supply space 10 projected on the light receiving unit 22 has a rectangular shape. Since the light in a cross section perpendicular to the light emission direction has a square shape, the pitch angle θy can be obtained from the dimensional change of the power supply space 10 projected on the light receiving unit 22. Similarly, the roll angle θx can also be obtained from the dimensional change of the power supply space 10 projected on the light receiving unit 22.

[0066] [UAV position measurement using the imaging unit] The unmanned aerial vehicle 2 can recognize and position itself by having the imaging unit 21 photograph the light source point 1 and grasp the positions of the light source point 1 and the photographed structures, etc. Furthermore, it can determine whether the current position of the unmanned aerial vehicle 2 is within the power supply space 10, and if the current position is outside the power supply space 10, the unmanned aerial vehicle 2 can be controlled so that the current position is within the power supply space 10.

[0067] When the unmanned aerial vehicle 2 is momentarily moved significantly due to a sudden gust of wind or the like, the movement of the unmanned aerial vehicle 2 cannot be corrected in time, and the light receiving unit 22 may fall out of the power supply space 10. If the light receiving unit 22 falls completely out of the power supply space 10, the position of the unmanned aerial vehicle 2 cannot be detected from the signal obtained by the light receiving unit 22. In that case, the position of the unmanned aerial vehicle 2 must be detected by another method. One of the other methods is the position detection of the unmanned aerial vehicle 2 by the imaging unit 21 of the unmanned aerial vehicle 2. The imaging unit 21 is used to detect the position of the unmanned aerial vehicle 2 by the imaging unit 21 of the unmanned aerial vehicle 2. Then, when the light receiving unit 22 is able to capture the power supply space 10, the position of the unmanned aerial vehicle 2 is detected by the light receiving unit 22. In other words, the rough position detection of the unmanned aerial vehicle 2 is performed by the imaging unit 21, and the precise position detection of the unmanned aerial vehicle 2 is performed by the light receiving unit 22.

[0068] The imaging unit 21 may be sensitive to visible light. It is preferable that the imaging unit 21 has low sensitivity to the wavelength of light emitted by the light source 11. An imaging unit other than the imaging unit 21 for monitoring purposes may be used for detecting the position of the unmanned aerial vehicle 2.

[0069] [UAV position measurement using the imaging unit at the light source] 12, the light source point 1 is equipped with two imaging units 18. The two imaging units 18 each capture an image of the unmanned aerial vehicle 2. This allows the light source point 1 to know the position of the unmanned aerial vehicle 2. In this embodiment, since the unmanned aerial vehicle 2 is captured by two imaging units 18, not only the horizontal position of the unmanned aerial vehicle 2 but also the altitude of the unmanned aerial vehicle 2 can be obtained based on the difference in the field of view of the two imaging units 18.

[0070] If the unmanned aerial vehicle 2 is hit by a sudden gust of wind or the like and moves significantly, the movement of the unmanned aerial vehicle 2 cannot be corrected in time, and the light receiving unit 22 may fall out of the power supply space 10. If the light receiving unit 22 falls out of the power supply space 10, the position of the unmanned aerial vehicle 2 must be adjusted by another method. In such a case, the imaging unit 18 provided at the light source point 1 is effective. Position information such as the horizontal position and altitude of the unmanned aerial vehicle 2 detected by the imaging unit 18 can be transmitted to the unmanned aerial vehicle 2 via the communication unit 17. In other words, position detection using the imaging unit 18 at the light source point can be used as one of the methods for roughly detecting the position of the unmanned aerial vehicle 2.

[0071] When adjusting the position of the unmanned aerial vehicle 2, it is preferable to obtain information regarding the size of the unmanned aerial vehicle 2 in advance in order to control the height of the unmanned aerial vehicle 2.

[0072] The imaging unit 18 may be sensitive to visible light. It is preferable that the imaging unit 18 has low sensitivity to the wavelength of light emitted by the light source 11. In this embodiment, the light source point 1 has two imaging units 18, but the number of imaging units 18 may be one or three or more.

[0073] The unmanned aerial vehicle 2 may be equipped with other position adjustment mechanisms. The unmanned aerial vehicle 2 may be equipped with, for example, an acceleration sensor or an angular velocity sensor, and the attitude of the unmanned aerial vehicle 2 may be controlled by the acceleration sensor or the angular velocity sensor. The unmanned aerial vehicle 2 may be equipped with a magnetic compass.

[0074] The unmanned aerial vehicle 2 may be equipped with a global positioning system (GPS) and may obtain its own position information. The unmanned aerial vehicle 2 may obtain its own position information by communicating with the light source point 1 or a remote control device 3 to learn its relative position with respect to the light source point 1.

[0075] [Details of the optical system of the light source and emitted light] FIG. 13 is an example of an optical system of the light source 11 and the emitted light of the light source 11 at the light source point 1. FIG. 14 is a view of the emission part 11o of the emitted light of the light source 11 from the emission side toward the light source 11. The light source 11 has a plurality of emitters inside. In this embodiment, the emitters are laser light emitting elements. In the emission part 11c of the light source 11, the emitted light 11a from each solid light source is arranged. In this embodiment, there are ten solid light sources, and five emitted light 11a are arranged in the X direction and two emitted light 11a are arranged in the Y direction. The shape of each emitted light 11a in a cross section perpendicular to the emission direction is a rectangle with chamfered corners. The shape of each emitted light 11a in a cross section perpendicular to the emission direction may be linear.

[0076] Light L1 emitted from the emission portion 11c is reflected by a reflecting mirror 51, condensed by a plano-convex lens 52, converted into parallel light by a plano-concave lens 53, and emitted from the light source point 1 via a light-transmitting plate 54. The optical axis of the emitted light L1 is represented by C2. The diameter of the emitted light L1 can be changed by changing the distance between the plano-convex lens 52 and the plano-concave lens 53. This optical system is one example, and other configurations may be used.

[0077] FIG. 15 shows the light intensity distribution of the emitted light at the light source point 1. If the light source emits light from one emitter, the intensity distribution will show a Gaussian distribution curve. However, since the light source 11 of this embodiment is a multimode laser light source in which the emitted light from a substantially rectangular emitter is arranged, the intensity distribution of the emitted light shows a top hat shape as shown in FIG. 15. The top hat light intensity distribution is a shape in which the light intensity distribution is relatively uniform in the power supply space 10, and the light intensity drops sharply from the inside to the outside of the power supply space 10, and the light intensity difference is clearly shown at the boundary between the inside and the outside. Therefore, the light source 11 can obtain high-output light suitable for position adjustment of the unmanned aerial vehicle using the light receiving unit 22.

[0078] When there is a problem with the light source point 1, for example when dust adheres to a part of the optical system of the light source point 1 causing a lack of light intensity distribution of the emitted light, or when the light source 11 itself deteriorates and cannot obtain bright light, the amount of stored power decreases. The unmanned aerial vehicle 2 may be designed to land on the ground by itself when it detects a decrease in the amount of stored power or a decrease in the light output from the light source point 1.

[0079] [Modifications of unmanned aerial vehicles] Fig. 16 shows a modified example of an unmanned aerial vehicle. Like the unmanned aerial vehicle 2 described above, the unmanned aerial vehicle 62 has an imaging unit 21, a light receiving unit 22, a power storage unit 24, a drive unit 25, an aircraft control unit 26, a communication unit 27, and rotors 28. However, Fig. 16 does not show anything other than the light receiving unit 22 and the drive unit 25. The unmanned aerial vehicle 62 has two features that the unmanned aerial vehicle 2 does not have.

[0080] First, a part of the downward air current generated by the rotor 28 is directed toward the light receiving unit 22. The light receiving unit 22 of the unmanned aerial vehicle 62 heats up by receiving light energy. When the light receiving unit 22 heats up to a predetermined temperature or higher, the photoelectric conversion efficiency of the light receiving unit 22 decreases. Therefore, by directing a part of the downward air current generated by the rotor 28 toward the light receiving unit 22, the cooling of the light receiving unit 22 is promoted. In this embodiment, the unmanned aerial vehicle 62 has a guide 45 on the back surface of the light receiving unit 22 for forming a flow against which a part of the downward air current collides.

[0081] Secondly, the beam profile camera 44 is used. In this embodiment, the amount of electromotive force generated by the photoelectric conversion elements is not monitored to detect the position and inclination of the unmanned aerial vehicle 62 (light-receiving unit 22). A portion of the light in the power supply space 10 passes through the gaps between the photoelectric conversion elements of the light-receiving unit 22. The beam profile camera 44 then images the rear surface of the light-receiving unit 22. In other words, the beam profile camera 44 images the light that has passed through the gaps between the photoelectric conversion elements of the light-receiving unit 22. This allows the optical energy received by the light-receiving unit 22 to be converted into electrical energy, while a portion of the light can be used to detect the position and inclination of the unmanned aerial vehicle 62.

[0082] [Second embodiment] A second embodiment of the system will be described with reference to Figs. 17 and 18. The matters described below can be implemented in the same manner as in the above-mentioned embodiment. Fig. 17 is a block diagram of the system of the second embodiment. Fig. 18 is a conceptual diagram of the system of the second embodiment. As shown in Fig. 18, the second system 200 includes a plurality of light source points 1a to 1d and a plurality of unmanned aerial vehicles 2. Furthermore, the second system 200 includes a remote control device 3. In the above-mentioned monitoring system 100, each light source point 1 controls the unmanned aerial vehicles 2, whereas in the second system 200, the remote control device 3 controls the plurality of light source points 1 and the plurality of unmanned aerial vehicles 2 in an integrated manner. Each light source point 1 and each unmanned aerial vehicle 2 may be designed to be controlled by the remote control device 3. For example, the unmanned aerial vehicle 2 may take off or land by remote control from the remote control device 3. Alternatively, while the unmanned aerial vehicle 2 itself flies autonomously, the unmanned aerial vehicle 2 may receive instructions regarding the imaging unit (for example, to start and stop shooting, or to change the lens direction or zoom setting, etc.) from the remote control device 3.

[0083] The remote control device 3 will now be described. The remote control device 3 includes a power supply unit 34, a remote device control unit 36, a communication unit 37, and an input / output unit 38. The power supply unit 34 may be connected to a commercial power source, a power generation device, or a storage battery. The power generation device includes power generation using fossil fuels, etc., and power generation using renewable energy such as solar, wind, hydroelectric, geothermal, or biomass.

[0084] The communication unit 37 of the remote control device 3 communicates with the communication unit 27 of the unmanned aerial vehicle and the communication unit 17 of the light source station 1. The input / output unit 38 includes an input unit through which the operator gives instructions to the remote control device 3, and an output unit through which the operator checks the operational status of the light source station 1 or the unmanned aerial vehicle 2, as well as information sent from the unmanned aerial vehicle 2. The output unit may be a display, a speaker, or a printer. The output unit may output information to another terminal (including a wearable device such as a smartphone) via a network line.

[0085] The control unit 36 ​​of the remote control device 3 has a function of controlling each unmanned aerial vehicle 2 of the second system 200. The control unit 36 ​​instructs each unmanned aerial vehicle 2 to take off and land.

[0086] The remote control device 3 instructs the unmanned aerial vehicle 2 to take pictures, and instructs the unmanned aerial vehicle 2 to send the taken pictures. The remote control device 3 may output the pictures sent from the unmanned aerial vehicle 2 to the input / output unit 38. The remote control device 3 may analyze the pictures sent from the unmanned aerial vehicle 2, and output the analysis results to the input / output unit 38.

[0087] If second system 200 does not have a remote control device, the captured images may be stored in a storage device within unmanned aerial vehicle 2, and the captured images may be analyzed after unmanned aerial vehicle 2 lands. Alternatively, unmanned aerial vehicle 2 may transmit the captured images to a receiving device that is not a remote control device (e.g., a wearable device such as a smartphone).

[0088] The present invention is not limited to the above-described embodiment, and various modifications and improvements can be made to the above-described embodiment without departing from the spirit and scope of the present invention.

[0089] For example, the above-mentioned system of the unmanned aerial vehicle 2 can be used for various monitoring targets. For example, the monitoring targets can be used to detect suspicious individuals or vermin invading farms and orchards. In addition, the growing conditions of fruits can be monitored. The monitoring targets can be factories, production machines, or transport machines. The monitoring targets can be used to detect fires in factories and to check for normal operation. Furthermore, the above-mentioned system can be used to monitor forest fires, landslides, river flooding, tsunamis, and the like. Furthermore, the unmanned aerial vehicle 2 can be used for bird watching, for ground surveying and weather observation, or can be equipped with a warning sound emitter to scare away birds and animals from specific areas (towns and airports), or can be equipped with a relay station or hub for wireless communication (radio or optical communication). [Explanation of symbols]

[0090] 1: Light source point 2,62:Unmanned aerial vehicle 3: Remote control device 10: Power supply space 10c: Center (of power supply space) 11:Light source 14: Power supply unit (at the light source) 16: Light source control section 17: (Light source location) Communications department 18: Imaging section 20: Field of view 21: Imaging unit 22: Light receiving part 22c: Center (of the light receiving part) 24: Power storage unit 25: Drive unit 26: Aircraft Control Unit 27: Communications section (of unmanned aerial vehicles) 28: Rotor 34: Power supply unit (for remote control device) 36: (Remote control device) control section 37: Communication section (of remote control device) 38: Input / output section 41: Photoelectric conversion element 42: Lens 44: Beam profile camera 45: Guide 51:Reflector 52: Plano-convex lens 53: Plano-concave lens 54: Translucent plate 100: Surveillance system 200: Second System Q1 :1st quadrant Q2 :Second quadrant Q3: Third quadrant Q4 :Fourth quadrant S: Composite vector θ1: Divergence angle θx: Roll angle θy: Pitch angle θz: Yaw angle

Claims

1. a light source point including a light source for emitting light from the ground in a state where the light is fixed so as to be emitted directly upward; the unmanned aerial vehicle having a light receiving unit that receives the light and converts it into electricity, a power storage unit that stores the electricity sent from the light receiving unit, a drive unit that rotates rotors using the electricity stored in the power storage unit, and a control unit that controls the drive unit; An unmanned aerial vehicle system, characterized in that the control unit controls the drive unit based on the distribution of light irradiated to the light receiving unit.

2. The system according to claim 1 , wherein the control unit controls the driving unit so that a center of the light irradiated to the light receiving unit is located at a predetermined position on the light receiving unit.

3. the light is divergent or convergent, The system described in claim 1 or 2, characterized in that the control unit derives the altitude at which the unmanned aerial vehicle will fly from the magnitude of the light irradiated to the light receiving unit, and controls the drive unit based on the derived altitude.

4. a light intensity distribution in a cross section perpendicular to the emission direction of the light is non-circular; The system according to claim 1 or 2, characterized in that the control unit detects an amount of rotation of the light in the light receiving unit and controls a yaw angle θz of the unmanned aerial vehicle.

5. The system described in claim 1 or 2, characterized in that the control unit detects the amount of change in the shape of the light received by the light receiving unit and controls the roll angle θx and pitch angle θy of the unmanned aerial vehicle.

6. The light receiving section is divided into a plurality of light receiving regions, Each of the light receiving regions is composed of a plurality of photoelectric conversion elements, The system according to claim 1 , wherein the control unit controls the drive unit based on an amount of photovoltaic power received for each of the light receiving regions.

7. the plurality of light receiving regions are composed of four regions, i.e., first to fourth quadrants, which are separated by a first axis and a second axis perpendicular to the first axis; The system described in claim 6, characterized in that the control unit controls the drive unit so that the center of the light irradiated to the light receiving unit is located at a predetermined position of the light receiving unit at the intersection of the first axis and the second axis.

8. 3. The system according to claim 1, wherein the light receiving section includes a plurality of photoelectric conversion elements and is capable of detecting an amount of photoelectromotive force generated by each of the photoelectric conversion elements.

9. 3. The system according to claim 1, further comprising a beam profile camera for detecting a light receiving state of the light receiving section by detecting a portion of the light passing through the light receiving section.

10. The unmanned aerial vehicle includes at least one of an angular velocity sensor and an acceleration sensor; The system according to claim 1 or 2, wherein the control unit acquires a signal from the angular velocity sensor or the acceleration sensor.

11. The unmanned aerial vehicle includes an imaging unit that images the ground, The system according to claim 1 , wherein the control unit autonomously controls the drive unit based on the image captured by the imaging unit.

12. The light source point includes an imaging unit, The system according to claim 1 or 2, characterized in that the light source point transmits information regarding the position of the unmanned aerial vehicle obtained from the imaging unit to the unmanned aerial vehicle.

13. 3. The system according to claim 1 or 2, characterized in that the intensity distribution of the light emitted by the light source point has a top hat shape.

14. The light source point includes a plurality of light sources that emit the light, 15. The system of claim 14, wherein the light output shape of each light source is rectangular or linear.

Images