JP2023175386A - flight system - Google Patents

Abstract

To provide a flight system capable of guiding an unmanned aircraft to a definite point easily and with high location accuracy.SOLUTION: A flight system comprises an unmanned aircraft and a display device which is identifiable from the sky and transfers a definite point to the unmanned aircraft. A first image element displayed on the display device and for indicating the definite point is a two-dimensional barcode including a hollow region, where a code is not displayed, and has a nest structure in which a second image element similar to the first image element is displayed while being reduced in the hollow region.SELECTED DRAWING: Figure 2

Description

FIELD OF THE INVENTION The present invention relates to flight systems.

In recent years, the range of applications for unmanned aerial vehicles (so-called drones) has expanded dramatically, including delivery systems, monitoring systems, and agricultural support such as pesticide spraying.

In recent years, the use of drones in conjunction with moving objects, such as cars, has been attracting attention. In this flight system including a mobile object and a drone, for example, the roof of a car serves as a takeoff and landing pad, and it is necessary to land a flying drone on this takeoff and landing pad.

This takeoff and landing pad generally has a smaller surface area than a static landing site set up on the ground. Furthermore, the drone that lands on the takeoff and landing pad provided on the mobile body is charged in preparation for re-flight. As this charging method, a non-contact charging system installed on a takeoff and landing pad is generally used. In such a non-contact charging system, the relative position of the coil provided on the drone with respect to the coil provided on the takeoff and landing pad greatly affects charging efficiency. In order to increase this charging efficiency, it is required to land the drone with high positional accuracy.

In response to this demand, a flight system has been proposed in which a takeoff and landing pad installed on a mobile object has a display device that can be identified from the sky, and an image including landing environment information is displayed on the display device (Japanese Patent Application Laid-Open No. 2020-2011-1). (See Publication No. 149640). This flight system improves landing position accuracy by transmitting landing environment information from the takeoff and landing pad through images.

JP2020-149640A

In the above flight system, an index of a certain size is required to visually confirm the landing position of a distant takeoff and landing pad from the drone side using image display. For example, when it is desired to control the position with an accuracy of several centimeters, if the size that can be recognized from a distance is several tens of centimeters, the size of this index itself can become a position error. On the other hand, if the landing environment information is transmitted from the takeoff and landing pad side via wireless communication or the like, a certain delay may occur depending on the communication environment and the like. This delay can lead to errors in position accuracy for fast-moving drones. In this way, it is difficult for drones to obtain highly accurate location information in real time.

The present invention was made based on the above-mentioned circumstances, and aims to provide a flight system that can easily guide an unmanned aircraft to a fixed point with high positional accuracy.

A flight system according to an embodiment of the present invention includes an unmanned aircraft and a display device that is distinguishable from the sky and that transmits a fixed point to the unmanned aircraft, and that is displayed on the display device to indicate the fixed point. The first image element is a two-dimensional barcode including a hollow area in which no code is displayed, and has a nested structure in which a second image element similar to the first image element is displayed in a reduced size in the hollow area.

The flight system of the present invention can easily guide an unmanned aircraft to a fixed point with high positional accuracy.

FIG. 1 is a configuration diagram showing a flight system according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing the automobile of FIG. 1 viewed from above. FIG. 3 is a block diagram showing a configuration example of the unmanned aircraft shown in FIG. 1. FIG. 4 is a block diagram showing an example of the configuration of the automobile shown in FIG. 1. As shown in FIG. FIG. 5 is a schematic diagram showing an example of an image displayed on the display device of FIG. 2. FIG. 6 is a schematic diagram showing the first image element of FIG. FIG. 7 is a schematic diagram showing the second image element of FIG.

[Description of embodiments of the present invention]
First, embodiments of the present invention will be listed and explained.

A flight system according to an embodiment of the present invention includes an unmanned aircraft and a display device that is distinguishable from the sky and that transmits a fixed point to the unmanned aircraft, and that is displayed on the display device to indicate the fixed point. The first image element is a two-dimensional barcode including a hollow area in which no code is displayed, and has a nested structure in which a second image element similar to the first image element is displayed in a reduced size in the hollow area.

In the flight system, the first image element and the second image element show the same code, and the second image element is smaller than the first image element and therefore has a higher resolution. With this configuration, the distance at which the first image element can be recognized is greater than the distance at which the second image element can be recognized, and the positional accuracy of the fixed point indicated by the second image element is higher than the positional accuracy of the fixed point indicated by the first image element. Therefore, the unmanned aircraft can recognize the first image element from a relatively long distance and approach the fixed point indicated by the first image element. Then, when the unmanned aircraft approaches the fixed point and reaches a distance where the second image element can be recognized, the unmanned aircraft can move to the fixed point with high positional accuracy by using the second image element.

It is preferable that the nested structure is repeated multiple times. By repeating the above-mentioned nested structure multiple times in this manner, the positional accuracy can be increased step by step, making it possible to guide the unmanned aircraft from a longer distance or with higher precision.

A marker indicating the fixed point may be displayed at the center of the hollow area. Since neither the first image element nor the second image element has a code in the hollow area, by displaying the marker at the center of this area, the fixed point can be easily recognized from the unmanned aircraft. .

The shape of the hollow region is preferably similar to the outer shape of the first image element, and the outer shape of the second image element and the shape of the hollow region preferably match. By establishing such a relationship among the shapes, the first image element and the second image element having a desired similarity ratio can be displayed in a small display area.

It is preferable that the unmanned aircraft includes a takeoff and landing pad on which the unmanned aircraft can take off and land, the display device is disposed on the takeoff and landing pad, and the fixed point is a landing point of the unmanned aircraft. The flight system is particularly suitably used when landing an unmanned aircraft on a takeoff and landing pad.

Here, "unmanned aircraft" is a general term for aircraft that do not have a human onboard and are operated remotely by radio or autonomously according to a pre-programmed pattern on the onboard computer, and are typically equipped with an autonomous navigation system. Refers to a small multi-rotor helicopter (drone). The term "above the sky" refers to an area where the angle between the zenith and the reference point on the ground is within 45 degrees and the relative altitude from the reference point is within 5 m.

[Details of embodiments of the present invention]
Hereinafter, a flight system according to an embodiment of the present invention will be explained in detail with reference to the drawings as appropriate.

The flight system shown in FIG. 1 includes an unmanned aircraft 1, a car 2 as a moving body, a takeoff and landing pad 3 mounted on the moving body and on which the unmanned aerial vehicle 1 can take off and land, and a takeoff and landing pad 3 as shown in FIG. and a display device 4 that is arranged and can be identified from the sky. The flight system is particularly preferably used when landing the unmanned aircraft 1 on the takeoff and landing pad 3.

In this flight system, an unmanned aircraft 1 is mounted on a takeoff and landing pad 3 of an automobile 2 and transported to a destination. After arriving at the destination, the unmanned aircraft 1 takes off from the takeoff and landing pad 3 and moves to a predetermined position. The unmanned aerial vehicle 1A that has moved to a predetermined position performs predetermined activities such as delivery, monitoring, and spraying of agricultural chemicals. Meanwhile, car 2 is moving. After completing the predetermined activity, the unmanned aircraft 1A moves to the car 2B and lands on the takeoff and landing pad 3. In FIG. 1, the unmanned aircraft 1B is shown in a state where it has landed on the takeoff and landing pad 3.

<Unmanned aircraft>
For example, as shown in FIG. 3, the unmanned aircraft 1 includes a storage section 11, a camera 12, an image recognition section 13, a sensor section 14, a landing control section 15, an aircraft control signal transmission/reception section 16, and a video data processing section. The configuration may include a wireless transmitter/receiver 17 and a communication controller 18 .

(Storage part)
The storage unit 11 stores various information temporarily or permanently. The storage unit 11 includes, for example, a semiconductor memory, a fixed disk, a removable disk, and the like.

Examples of the information stored in the storage unit 11 include ID information of the unmanned aircraft 1 (own aircraft), ID information of the car 2 to be landed, and the like. Further, for example, when the image recognition section 13 performs image processing, the storage section 11 may be used to temporarily store the processed data.

(camera)
As shown in FIG. 1, the camera 12 is installed so that the unmanned aircraft 1 can take an image of the area below when it lands. Although the specific position is not particularly limited, for example, as shown in FIG. 1, the lens is attached to the lower surface of the fuselage of the unmanned aircraft 1 so as to face downward.

As the camera 12, a known camera that can be mounted on the unmanned aircraft 1 can be used. The camera 12 may be used in common, for example, with a camera that takes pictures of landscapes and topography, monitors the surroundings during flight, and the like.

The camera 12 can capture an image 5 displayed on a display device 4 of the takeoff and landing pad 3, which will be described later. The photographed image 5 is stored in the storage unit 11 via the communication control unit 18, which will be described later.

(Image recognition section)
The image recognition unit 13 recognizes the image 5 displayed on the display device 4 using the camera 12 . The image recognition unit 13 can be configured by, for example, an arithmetic processing device such as a CPU (Central Processing Unit). As the arithmetic processing device, a processor dedicated to image processing such as a DSP (Digital Signal Processor) may be used.

Specifically, the image recognition unit 13 reads out images captured by the camera 12 stored in the storage unit 11 via the communication control unit 18, which will be described later, and performs arithmetic processing (so-called image processing) on the images. This will extract the information necessary for landing (landing environment information). The extracted landing environment information will be described later.

(Sensor part)
The sensor unit 14 includes known body sensors such as a gyro sensor, a speed sensor, and a navigation sensor for detecting the position, flight status, etc. of the unmanned aircraft 1.

Further, the sensor unit 14 may include an environment sensor that measures the environment around the unmanned aircraft 1. Examples of the environmental sensor include a sensor that detects the relative movement (position, speed, and direction of travel) of the car 2 as seen from the unmanned aircraft 1, and a sensor that detects obstacles between the unmanned aircraft 1 and the takeoff and landing pad 3. can be mentioned. There is an altitude difference between the unmanned aircraft 1 and the takeoff and landing pad 3 until it lands on the takeoff and landing pad 3. Particularly at a stage where the difference in altitude is large, the wind speed and direction of airflow are different from the takeoff and landing pad 3 on the ground. Since the unmanned aircraft 1 is flying, errors may occur in the flight control for landing due to these wind speeds and air currents, but by providing an environmental sensor that detects the relative movement of the car 2 as the environmental sensor, this error can be eliminated. It becomes easier to correct. Furthermore, by providing a sensor that detects obstacles, etc., it is possible to easily search for a safe landing route.

(Landing control section)
The landing control unit 15 determines the flight path based on information obtained mainly from the image recognition unit 13 and, if necessary, the sensor unit 14 and the aircraft control signal transmitting/receiving unit 16 (described later), and safely flies the unmanned aircraft 1. The attitude, speed, and direction of movement of the unmanned aircraft 1 are controlled so that it can land on the takeoff and landing pad 3.

The landing control unit 15 includes an arithmetic processing unit, such as a CPU, which calculates the flight path and the attitude that the unmanned aircraft 1 should take, and a flight control device for the unmanned aircraft 1. The arithmetic processing device described above may serve as part or all of another arithmetic processing device, such as the arithmetic processing device of the image recognition section 13, or may be provided independently. Since the flight control device of the unmanned aircraft 1 is well known, detailed explanation will be omitted.

(Aircraft control signal transmitter/receiver)
The aircraft control signal transmitting/receiving unit 16 is an antenna for transmitting and receiving aircraft control signals between the automobile 2 and the unmanned aircraft 1.

If the unmanned aircraft 1 is to land, the aircraft control signal may be a known landing signal, such as a landing request signal from the unmanned aircraft 1 to the car 2 or a landing permission signal from the car 2 to the unmanned aircraft 1. Examples include signals necessary for operation.

The aircraft control signal transmitting/receiving unit 16 is also configured to be able to communicate with a GPS (Global Positioning System) satellite for confirming position information of the unmanned aircraft 1.

(Wireless transmitter/receiver for video data)
The video data wireless transmission/reception unit 17 is an antenna for transmitting video data photographed by the camera 12 to the automobile 2 and for receiving video data photographed by the automobile 2.

The video data wireless transmitter/receiver 17 may serve as a single antenna that also serves as the aircraft control signal transmitter/receiver 16, but is preferably provided separately from the viewpoint of improving the efficiency of data transmission and reception.

(Communication control unit)
The communication control unit 18 performs modulation/demodulation, encoding, and decoding for communicating with the automobile 2 using the aircraft control signal transmission/reception unit 16 and the video data wireless transmission/reception unit 17, and also performs modulation/demodulation, encoding, and decoding for communicating with the automobile 2, and also controls the storage unit 11, camera 12, and image recognition. It controls data exchange between the unit 13, the sensor unit 14, the landing control unit 15, the aircraft control signal transmitting/receiving unit 16, and the video data wireless transmitting/receiving unit 17.

This communication control unit 18 can be configured by, for example, an arithmetic processing device such as a CPU. The arithmetic processing device described above may serve as part or all of other arithmetic processing devices, such as the arithmetic processing device of the image recognition section 13 and the landing control section 15, or may be provided independently.

The line through which the communication control unit 18 communicates with the vehicle 2 is not particularly limited, and may be a known line, such as a 3G band or 4G band used for mobile, WiFi (wireless LAN according to IEEE 802.11 standard), or ITS (Intelligent Transport Systems: DSRC (Dedicated Short Range Communications) used in intelligent transportation systems can be used.

<Automobile>
The automobile 2 includes an on-vehicle device 6 for controlling the unmanned aerial vehicle 1, as shown in FIG. The onboard device 6 includes, for example, a display control section 60, a storage section 61, a camera 62, an image recognition section 63, a sensor section 64, a distance/azimuth calculation section 65, a command generation section 66, and a signal transmission/reception unit for aircraft control. 67 , a video data wireless transmitter/receiver 68 , and a communication controller 69 .

(Display control section)
The display control unit 60 displays the image 5 on the display device 4. Specifically, the display control unit 60 creates image information data that constitutes an image 5 to be displayed on the display device 4, which will be described later, and transmits it to the display device 4. This display control section 60 can be configured by, for example, an arithmetic processing device such as a CPU.

(Storage part)
The storage unit 61 stores various information temporarily or permanently. The storage unit 61 can be configured similarly to the storage unit 11 of the unmanned aircraft 1.

A database may be stored in part of the area of the storage unit 61. This database stores various information such as the ID of the unmanned aircraft 1 and sequence procedures for control, voice recognition data necessary for HMI (Human Machine Interface), etc., and is used to realize control of multiple types of unmanned aircraft 1. This makes it possible to recognize voice instructions from passengers.

(camera)
The camera 62 is used to photograph the unmanned aircraft 1 that is in a landing position on the takeoff and landing pad 3 of the automobile 2 from the automobile 2 side.

The type of camera 62 is not particularly limited as long as it can photograph the unmanned aircraft 1. Further, the camera 62 is installed above the automobile 2 so as to be able to take a picture of the unmanned aircraft 1, preferably on the takeoff and landing pad 3 so as to be able to take a picture of the sky.

Images taken by the camera 62 are stored in the storage unit 61 via a communication control unit 69, which will be described later.

(Image recognition section)
The image recognition unit 63 recognizes the unmanned aircraft 1 photographed by the camera 62 as described above. This image recognition unit 63 can be configured in the same manner as the image recognition unit 13 of the unmanned aircraft 1, except that the recognition target is the unmanned aerial vehicle 1.

(Sensor part)
The sensor unit 64 includes a measuring device for acquiring the position, altitude, wind speed, and illuminance of the takeoff and landing pad 3, as well as the speed and traveling direction of the automobile 2.

The position of the takeoff and landing pad 3 can be obtained based on information from GPS satellites. The altitude of the takeoff and landing pad 3 may be based on information from a GPS satellite, but the sensor section 64 may also include an altimeter. The wind speed and illuminance of the takeoff and landing pad 3 can be obtained by providing the sensor section 64 with an anemometer or an illumination meter. The speed of the automobile 2 can be obtained by using a speedometer that the automobile 2 has for self-propulsion. The traveling direction of the automobile 2 may be based on information from a GPS satellite, but the sensor section 64 may also include a compass.

(Distance and direction calculation section)
The distance/azimuth calculation unit 65 calculates the distance and azimuth between the flying unmanned aircraft 1 and the automobile 2, which are in a landing position. The distance/azimuth calculation section 65 can be configured by, for example, a calculation processing device such as a CPU. This arithmetic processing device may serve as part or all of other arithmetic processing devices, such as the arithmetic processing device of the image recognition section 63, or may be provided independently. The same applies to the components configured by the arithmetic processing units below.

Since the unmanned aerial vehicle 1 is relatively small, the reference point for measuring the distance and direction can be represented by, for example, the center of gravity position of the unmanned aerial vehicle 1. On the other hand, since the car 2 is relatively large, it is preferable to set the reference point for measuring the distance and direction to the takeoff and landing pad 3 where the unmanned aircraft 1 actually lands, and the center position when the unmanned aircraft 1 actually lands. It is more preferable to set it at a fixed point (details will be described later). By determining the base point in this way, it is possible to improve the accuracy of the distance and direction required for landing.

The distance and direction between the unmanned aerial vehicle 1 and the automobile 2 can be calculated using the image data of the drone taken by the camera 62 and the shooting direction of the camera 62. Alternatively, image data transmitted from the unmanned aircraft 1 via the video data wireless transmitter/receiver 17 may be used. Furthermore, position information of the unmanned aircraft 1 and the automobile 2 from GPS satellites can also be used. These may be used alone or in combination of two or more. By using them in combination, it is possible to improve the calculation accuracy of distance and direction.

(command generation part)
The command generation unit 66 generates information including landing environment information to be displayed on the display device 4 of the takeoff and landing pad 3, and generates control commands to the unmanned aircraft 1 corresponding to the information. The command generation unit 66 can be configured by, for example, an arithmetic processing device such as a CPU.

Information including the landing environment information is transmitted to the display control section 60 via a communication control section 69, which will be described later, and image information data is created by the display control section 60 and displayed on the display device 4. The command generation unit 66 uses the position, altitude, wind speed, and illuminance of the takeoff and landing pad 3, as well as the speed and traveling direction of the automobile 2, which are information acquired by the sensor unit 64, as the landing environment information. That is, the landing environment information includes at least one of the position, altitude, and illuminance of the takeoff and landing pad 3, and the speed and traveling direction of the automobile 2. By including at least one of these as the landing environment information, information that is likely to change as the automobile 2 moves can be used for landing control of the unmanned aircraft 1, making landing control easier. Moreover, the accuracy of landing position can be further improved.

The command generation unit 66 generates information to be displayed on the display device 4 in real time when the unmanned aircraft 1 lands. Since image information data is created by the display control unit 60 based on information from the command generation unit 66 and displayed on the display device 4, the image information data displayed by the display control unit 60 allows the above-mentioned landing when the unmanned aircraft 1 lands. Environmental information is updated in real time. By updating the landing environment information substantially in real time when the unmanned aircraft 1 lands using the image 5 displayed by the display control unit 60 in this manner, the accuracy of the landing position can be further improved. Note that "real time" includes a case where update work is performed at predetermined intervals, and the predetermined interval is 10 minutes or less, preferably 5 minutes or less.

On the other hand, the control command is transmitted from the aircraft control signal transmitting/receiving section 67 to the unmanned aircraft 1 via the communication control section 69. The control command sent to the unmanned aircraft 1 is received by the aircraft control signal transmitting/receiving unit 16 of the unmanned aircraft 1 and sent to the landing control unit 15. Note that this control command is mainly a command for controlling the aircraft, but may include other commands.

(Aircraft control signal transmitter/receiver)
The aircraft control signal transmitting/receiving unit 67 is an antenna for transmitting and receiving aircraft control signals between the automobile 2 and the unmanned aircraft 1. This aircraft control signal transmitting/receiving unit 67 is configured similarly to the aircraft controlling signal transmitting/receiving unit 16 of the unmanned aircraft 1.

(Wireless transmitter/receiver for video data)
The video data wireless transmission/reception unit 68 is an antenna for transmitting video data photographed by the camera 62 to the unmanned aircraft 1 and for receiving video data photographed by the unmanned aircraft 1. This video data wireless transmitter/receiver 68 is configured similarly to the video data wireless transmitter/receiver 17 of the unmanned aircraft 1.

(Communication control unit)
The communication control unit 69 performs modulation/demodulation, encoding, and decoding for communicating with the unmanned aircraft 1 in the aircraft control signal transmission/reception unit 67 and the video data wireless transmission/reception unit 68, and also performs modulation/demodulation, encoding, and decoding for communicating with the unmanned aircraft 1. , the camera 62, the image recognition section 63, the sensor section 64, the distance/azimuth calculation section 65, the command generation section 66, the aircraft control signal transmission/reception section 67, and the video data wireless transmission/reception section 68. .

This communication control section 69 can be configured by, for example, an arithmetic processing device such as a CPU. Further, as a line for communication, a line corresponding to the communication control unit 18 of the unmanned aircraft 1 is used.

<Takeoff and landing pad>
The installation position of the take-off and landing pad 3 is not particularly limited as long as the unmanned aircraft 1 can land thereon, and may be any suitable position such as the roof of the automobile 2, the loading platform, or the hood, as shown in FIG. Further, the width of the takeoff and landing pad 3 is set to be large enough to allow the unmanned aircraft 1 to land thereon.

<Display device>
The display device 4 communicates the fixed point to the unmanned aerial vehicle 1. The fixed point is a target spot on the flight path of the unmanned aircraft 1, and when taking off and landing as in the flight system, the fixed point can be the landing point of the unmanned aircraft 1. Note that the fixed point does not necessarily have to be a landing point, and may be, for example, one of the corners of the takeoff and landing pad 3. In this case, the unmanned aircraft 1 will determine the landing point as a relative position from the fixed point and will land.

The display device 4 is arranged on the upper surface side of the takeoff and landing pad 3. It is also possible to arrange the display device 4 on the outermost surface of the take-off and landing pad 3 and land the unmanned aircraft 1 on the display device 4 itself, but the take-off and landing pad 3 has a mesh-like surface and the air flowing in from the surface side is It is preferable that the display device 4 is constructed of a hollow plate-like member having air holes that flow out to the side, and that the display device 4 is disposed in the hollow portion of the member at a position that does not prevent air from flowing out to the side. In such a configuration, the unmanned aircraft 1 lands on the mesh portion of the member. When the unmanned aircraft 1 lands, it generates a strong downward airflow, and this downward airflow passes through the mesh and flows out to the side through the air holes. Therefore, the influence of the reflected airflow from the takeoff and landing pad 3, which tends to occur immediately before the unmanned aircraft 1 lands, can be reduced, and the stability of the landing control of the unmanned aircraft 1 can be improved. Further, by disposing the display device 4 in the hollow part of the above-mentioned member, the unmanned aircraft 1 does not land directly, so that the occurrence of failure or damage of the display device 4 can be reduced. Note that in this configuration, the diameter of the mesh is made coarse enough to make the display on the display device 4 recognizable from above.

As the display device 4, a known liquid crystal display or the like can be used, but a flexible display is particularly preferred. By using a flexible display, it can be appropriately placed on the takeoff and landing pad 3 when image display is required, and it can be stored when not needed, thereby reducing the occurrence of failures or damage to the display device 4. Furthermore, since the flexible display is thin, it is unlikely to affect the downward airflow when the unmanned aircraft 1 lands.

The shape of the display device 4 (the shape of the display screen in plan view) can be square or rectangular (also referred to as "square"). By making the display device 4 rectangular in shape, an existing display can be easily used. Furthermore, the shape of the display device 4 may be circular. By making the shape of the display device 4 circular and using its center as the fixed point, the fixed point can be easily recognized from the unmanned aircraft 1.

The lower limit of the length of one side of the display device 4 (when the display device 4 is circular, the length of its diameter) is preferably 30 cm, more preferably 40 cm. On the other hand, the upper limit of the length of one side of the display device 4 is preferably 100 cm, more preferably 60 cm. If the length of one side of the display device 4 is less than the above-mentioned lower limit, the size of the image 5 will be restricted, and the distance that can be recognized from the unmanned aircraft 1 may become short. Conversely, if the length of one side of the display device 4 exceeds the above upper limit, there is a risk that it will be difficult to arrange it on the takeoff and landing pad 3, or that the takeoff and landing pad 3 will become unnecessarily large.

The display device 4 is preferably one that can be dimmed, and preferably one that can display color. Further, the lower limit of the maximum light amount of the display device 4 is preferably 4000 LUX, and more preferably 4500 LUX. If the maximum light amount of the display device 4 is less than the above lower limit, the brightness of the image 5 will be restricted, and the distance that can be recognized from the unmanned aircraft 1 may become short. On the other hand, the upper limit of the maximum light amount of the display device 4 is not particularly limited, but is set to, for example, 10,000 LUX from the viewpoint of power consumption and the like.

<Image>
The image 5 displayed on the display device 4 in the flight system will be explained. The image 5 is composed of a first image element 51, a second image element 52, a third image element 53, and a marker 54, as shown in FIG. Note that in FIG. 5, arrows indicate the direction in which the automobile 2 is traveling.

(first image element)
The first image element 51 is an image element displayed on the display device 4 to indicate the fixed point. The first image element 51, as shown in FIG. 6, is a two-dimensional barcode including a hollow area 51x where no code is displayed.

In the first image element 51 shown in FIG. 6, the two-dimensional barcode is an 8×8 square matrix, and the 4×4 matrix in the center is not used as the hollow area 51x. In other words, the shape of the hollow region 51x is similar to the outer shape of the first image element 51. Note that this configuration is an example and does not preclude other configurations.

The lower limit of the length of one side of a square constituting one square of a two-dimensional barcode is preferably 3 cm, and more preferably 4 cm. On the other hand, the upper limit of the length of one side is preferably 7 cm, more preferably 6 cm. If the length of one side is less than the lower limit, the distance that can be recognized from the unmanned aircraft 1 may become short. Conversely, if the length of one side exceeds the upper limit, there is a risk that the image cannot be displayed on the display device 4, or that the information that can be transmitted to the unmanned aircraft 1 by the first image element 51 becomes insufficient.

For example, codes can be assigned to the two-dimensional barcode as follows. Note that this is just an example, and the code assignment can be determined arbitrarily.

A fixed forward pattern 51a is assigned to the first row from the front. Further, a fixed backward pattern 51b is allocated to the fifth row (last row) from the front. By referring to these two patterns, the traveling direction of the automobile 2 can be known.

A landing environment information pattern 51c is assigned to the second to seventh columns located in the middle. This landing environment information is environmental information obtained on the vehicle 2 side as described above, and is generated by the command generation unit 66 provided in the on-vehicle device 6 of the vehicle 2.

(Second image element)
The second image element 52 shown in FIG. 7 is similar to the first image element 51, and is displayed in a reduced size in the hollow area 51x of the first image element 51 (see FIG. 5). In other words, the first image element 51 and the second image element 52 have a nested structure.

The two-dimensional barcode displayed in the second image element 52 is the same as the two-dimensional barcode displayed in the first image element 51, including the value.

As shown in FIG. 5, it is preferable that the outer shape of the second image element 52 and the shape of the hollow region 51x of the first image element 51 match. By establishing such a relationship among the shapes, the first image element 51 and the second image element 52 having a desired similarity ratio can be displayed in a small display area.

The similarity ratio between the first image element 51 and the second image element 52 is preferably 1.5:1 or more and 3:1 or less. If the above-mentioned similarity ratio is less than the above-mentioned lower limit, it will be necessary to make the hollow region 51x wide, which may limit the amount of information included in each image. Conversely, if the similarity ratio exceeds the upper limit, smooth landing control of the unmanned aircraft 1 may become difficult.

(Third image element)
The third image element 53 is similar to the second image element 52, and is displayed in a reduced size in the hollow area 52x of the second image element 52 (see FIG. 5). In other words, both the second image element 52 and the third image element 53 have a nested structure. Note that the relationship of the third image element 53 to the second image element 52 is the same as the relationship of the second image element 52 to the first image element 51, so a detailed explanation of the third image element 53 will be omitted.

The nested structure may be, for example, only the first image element 51 and the second image element 52 (only once), but it is preferable that it be repeated multiple times (twice in FIG. 5) in this way. By repeating the nested structure a plurality of times, the positional accuracy can be increased step by step, so the unmanned aircraft 1 can be guided from a longer distance or with higher accuracy.

The number of nested structures is preferably 2 or more and 5 or less. If the number of the nested structures is less than the lower limit (ie, 1), the effect of increasing the positional accuracy in stages cannot be obtained. On the other hand, if the number of nested structures exceeds the upper limit, the effect of improving position accuracy by increasing the number of nested structures may be insufficient.

(marker)
Marker 54 indicates the fixed point. In this flight system, the unmanned aircraft 1 lands at this fixed point.

Although the marker 54 can be displayed at any position, it is preferably displayed at the center of the hollow area 51x (52x). Since neither the first image element 51 nor the second image element 52 has a code in the hollow area 51x, displaying the marker 54 in the center of this area makes it easier for the unmanned aircraft 1 to recognize the fixed point. be able to.

The shape of the marker 54 is not particularly limited, but may be annular or circular. Although the size of the marker 54 depends on the required positional accuracy, it can be, for example, 1 cm or more and 3 cm or less in diameter. In this case, control with an error of several centimeters is possible.

<Landing control method>
In explaining the landing control method in the flight system, first, the flight of the unmanned aircraft 1 will be briefly explained. The unmanned aerial vehicle 1 is used for delivery systems, monitoring systems, agricultural support, and the like. For example, when acquiring a landscape image around the car 2 from the car 2 using the unmanned aerial vehicle 1 as a monitoring system, the unmanned aerial vehicle 1 takes off from the car 2, ascends, and then hovers above the car 2. Next, after quickly moving to the destination in horizontal flight, it hovers in the sky near the destination and moves at a relatively low speed to the final shooting point while adjusting the altitude and position. After acquiring a landscape image at the shooting point, the aircraft returns to a level flight altitude and quickly moves to the vicinity of the landing site. After moving near the landing site, descend and land. Note that although the above description is based on the case where images are taken only at the photographing points, it is also possible to acquire images during horizontal flight.

This landing control method is used in the process of returning to an altitude for level flight, quickly moving to the vicinity of the landing site, descending, and landing. The above landing control method is divided into a guidance step and a landing step.

(Induction step)
In the guidance step, the automobile 2 guides the unmanned aircraft 1 to a position where the camera 12 of the unmanned aircraft 1 can recognize the image 5 on the display device 4 of the takeoff and landing pad 3.

Specifically, a control command related to a landing instruction generated by the command generating unit 66 of the on-vehicle device 6 of the automobile 2 is transmitted to the unmanned aircraft 1 via the aircraft control signal transmitting/receiving unit 67. This control command includes, for example, the ID of the automobile 2 (hereinafter referred to as "vehicle ID"), the ID of the unmanned aircraft 1 (hereinafter referred to as "aircraft ID"), the landing point position, the expected arrival time, and the like.

The vehicle ID is a unique ID of the vehicle 2, and the unmanned aircraft 1 can specify the vehicle 2 on which it should land based on this vehicle ID. Further, the aircraft ID is a unique ID of the unmanned aircraft 1, and the unmanned aircraft 1 can recognize whether the control command is for its own aircraft or not based on this aircraft ID.

The landing point position is a location where the unmanned aircraft 1 is scheduled to land, and is also a destination where the automobile 2 moves to accommodate the unmanned aircraft 1. This landing point position may be determined using position information defined by GPS, and is a spot determined in advance between the unmanned aircraft 1 and the car 2 and stored in the storage unit 11 of the unmanned aircraft 1 and the storage unit 61 of the car 2. You may also use the first name. Furthermore, the estimated arrival time is the estimated time when the automobile 2 completes its movement to the landing point position.

In this flight system, the vehicle 2 on which the unmanned aerial vehicle 1 takes off and lands is movable while the unmanned aerial vehicle 1 is working. Therefore, the position where the unmanned aircraft 1 takes off and the position where it lands are not necessarily the same. Further, the automobile 2 is not necessarily at the landing position of the unmanned aircraft 1 at the time this control command is transmitted. Therefore, it is necessary to share information on the landing site location and estimated arrival time with the unmanned aircraft 1.

The unmanned aircraft 1 that receives the control command regarding this landing instruction via the aircraft control signal transmitting/receiving unit 16 checks the vehicle ID and aircraft ID in the communication control unit 18, and confirms that the command is directed to its own aircraft and that it is scheduled to land. Recognize the landing point positions of the vehicle 2 and own aircraft.

The unmanned aircraft 1 adds, for example, its current position and expected landing time acquired from the information of the sensor section 14 to the vehicle ID and the aircraft ID, and transmits them to the automobile 2 via the aircraft control signal transmitting/receiving section 16. For example, the expected landing time can be calculated using the current position of the aircraft, the scheduled landing point, and the scheduled flight speed of the aircraft. Note that it is not essential to transmit this information to the automobile 2, and for example, only a signal indicating that a control command for landing instruction has been received may be transmitted.

After exchanging these control commands, the unmanned aircraft 1 and the automobile 2 head to the scheduled landing site. Information such as the landing point location and estimated time of arrival is information that can change during movement, so it may be updated periodically or whenever a certain change occurs. This information can be updated by performing the guidance step again.

(Landing step)
This step is performed after the vehicle 2 and the unmanned aerial vehicle 1 have moved to the landing site position. Whether or not the unmanned aircraft 1 is moving to the landing site position is determined based on whether the unmanned aircraft 1 can recognize the two-dimensional barcode of the first image element 51. If the recognition is not possible, continue the guidance step and bring the unmanned aircraft 1 closer to the vehicle 2, or if it is determined that the altitude is low, increase the altitude of the unmanned aerial vehicle 1 to improve the visibility of the first image element 51. It may be increased.

When switching from the guidance step to the landing step, the first image element 51 can be recognized, but the second image element 52, the third image element 53, and the marker 54, which are smaller than the first image element 51, cannot be recognized. It can be. However, since the unmanned aircraft 1 can recognize the largest first image element 51, it can continue approaching the fixed point based on the information of the first image element 51. Since the second image element 52 and the following cannot be recognized, the unmanned aircraft 1 and the fixed point are far away at this stage, and the allowable error is large. Therefore, it is possible to continue the approach using only the information of the first image element 51.

After entering the landing step, the unmanned aircraft 1 basically has to approach the fixed point indicated by the first image element 51. For example, when based on the image 5 shown in FIG. 5, it is known that the fixed point is located in the hollow region 51 All you have to do is approach the area 51x.

As mentioned above, the unmanned aircraft 1 can continue its approach using only the information obtained from the camera 12 and sensor unit 14 of the unmanned aircraft 1 itself, but by also using the landing environment information from the car 2 side, it is possible to carry out a detailed flight. control and improve landing position accuracy. This landing information from the automobile 2 side can be obtained by the following procedure via the landing environment information pattern 51c.

First, the automobile 2 acquires the position, altitude, and illuminance of the takeoff and landing pad 3, as well as the speed and traveling direction of the automobile 2, using the sensor unit 64 of the on-vehicle device 6. Further, the distance/azimuth calculating section 65 calculates the distance and the azimuth between the flying unmanned aircraft 1 and the automobile 2 which are in a landing position based on information obtained from the camera 62 and the like.

The position, altitude, wind speed and illuminance of the takeoff and landing pad 3, the speed and direction of travel of the automobile 2, and the distance and direction between the unmanned aircraft 1 and the automobile 2 are displayed on the display device 4 via the display control unit 60 in a landing environment information pattern. 51c. Information other than the above information, such as vehicle ID and aircraft ID, may also be displayed in the landing environment information pattern 51c. Furthermore, it is not necessary to display all of the above information at the same time; for example, only the information that has changed may be displayed, or it may be displayed sequentially in a time-sharing manner.

Then, the unmanned aircraft 1 uses the image recognition unit 13 to recognize the first image element 51 from the video with the camera 12, extracts landing environment information from the landing environment information pattern 51c, and uses it for landing control of the unmanned aircraft 1.

For example, if the extracted landing environment information includes vehicle ID and aircraft ID information, the image recognition unit 13 verifies whether or not the own aircraft is the target for landing based on the vehicle ID and aircraft ID information. . If the comparison cannot be made, the guidance step is re-executed by communicating with the on-vehicle device 6 of the automobile 2, for example, and the vehicle moves to the correct landing place. If the verification is successful, continue extracting the landing environment information.

Although the speed and traveling direction of the automobile 2 can be determined from changes over time in the image of the camera 12 of the unmanned aircraft 1, the speed and traveling direction of the automobile 2 included in the landing environment information pattern 51c transmitted as landing environment information are By using , the accuracy can be improved.

Further, the distance and direction between the unmanned aerial vehicle 1 and the automobile 2 can be calculated using only the image taken by the camera 12 of the unmanned aerial vehicle 1, but errors may occur depending on atmospheric conditions and the like. This error is reduced by referring to the information on the distance and direction between the unmanned aircraft 1 and the car 2 measured from the car 2 side, which is included in the landing environment information pattern 51c transmitted as the landing environment information. Thereby, the landing accuracy of the unmanned aircraft 1 can be improved.

Furthermore, the landing attitude can be slightly modified based on the actual wind speed at the landing site based on the wind speed at the takeoff and landing pad 3 included in the landing environment information pattern 51c transmitted as the landing environment information.

As the approach continues based on the first image element 51, the distance between the unmanned aircraft 1 and the image 5 decreases, and eventually the unmanned aircraft 1 becomes able to recognize the second image element 52. At this time, the unmanned aircraft 1 switches the target for acquiring information from the first image element 51 to the second image element 52. Since the second image element 52 is smaller in size than the first image element 51, control errors can be reduced by approaching a smaller target. Since the information contained in the second image element 52 is the same as the first image element 51, the approach can be continued without intermittent flight control or initialization. Further, since the second image element 52 is displayed in the hollow area 51x of the first image element 51, even if the first image element 51 is switched to the second image element 52, the direction of the camera 12 does not need to be changed. OK, even if you need to make changes, it's only a minor adjustment.

If the approach is further continued based on the second image element 52, the unmanned aircraft 1 will be able to recognize the third image element 53, and will switch the object of information acquisition to this third image element 53. Eventually, the unmanned aerial vehicle 1 can recognize the marker 54 and land on the marker 54, which is a fixed point indicating the landing point of the unmanned aerial vehicle 1.

<Advantages>
In this flight system, the first image element 51 and the second image element 52 show the same code, and the second image element 52 is smaller than the first image element 51, and therefore has a higher resolution. With this configuration, the distance at which the first image element 51 can be recognized is greater than the distance at which the second image element 52 can be recognized, and the positional accuracy of the fixed point indicated by the second image element 52 is the positional accuracy of the fixed point indicated by the first image element 51. higher than Therefore, the unmanned aircraft 1 can recognize the first image element 51 from a relatively long distance and approach the fixed point indicated by the first image element 51. Then, when the unmanned aircraft 1 approaches the fixed point and reaches a distance where the second image element 52 can be recognized, the unmanned aircraft 1 can move to the fixed point with high positional accuracy by using the second image element 52.

[Other embodiments]
The above embodiments do not limit the configuration of the present invention. Therefore, in the above embodiment, it is possible to omit, replace, or add components of each part of the above embodiment based on the description of this specification and common general technical knowledge, and all of these are interpreted as falling within the scope of the present invention. Should.

In the above embodiment, a case has been described in which the moving body is a car, but the moving body is not limited to a car. A mobile object refers to a vehicle that can self-propel on land or water, and includes automobiles, motorcycles, ships, etc.

Further, the takeoff and landing pad is not limited to one mounted on a moving body, but may be one fixed on land or water.

Furthermore, the display device is not limited to one that is mounted on a takeoff and landing pad, but includes one that is placed at a specific point, such as the position of a farm that a drone should observe at a fixed point, for example.

In the above embodiment, a case has been described in which the two-dimensional barcode of the image element includes the landing environment information pattern, but it is not an essential component to include the landing environment information pattern. It may also be a two-dimensional barcode that conveys only the position of a fixed point. In this case, all or part of the functions of acquiring environmental information on the mobile body and displaying it on the display device may be omitted.

In the above embodiments, a case has been described in which an unmanned aircraft and a car have a configuration that allows communication with a GPS satellite, but the present invention is also applicable to a flight system that does not communicate with a GPS satellite. An example of such a flight system is a system in which an unmanned aircraft flies while recognizing the position (direction and distance) of a car by receiving radio waves transmitted from the car.

In the above embodiment, the case where the unmanned aircraft is equipped with a wireless transmission/reception unit for video data has been described, but for example, if there is no video data taken by a car or if it is not used on the unmanned aircraft side, the unmanned aircraft may have only a transmission function. You can. Similarly, the device may have only a receiving function, or may not include a video data wireless transmitter/receiver.

As described above, the flight system of the present invention can easily guide an unmanned aircraft to a fixed point with high positional accuracy.

1, 1A, 1B Unmanned aircraft 11 Storage unit 12 Camera 13 Image recognition unit 14 Sensor unit 15 Landing control unit 16 Aircraft control signal transmission and reception unit 17 Video data wireless transmission and reception unit 18 Communication control unit 2, 2B Car 3 Takeoff and landing pad 4 Display Device 5 Image 51 First image element 51a Forward direction pattern 51b Backward direction pattern 51c Landing environment information pattern 51x Hollow area 52 Second image element 52x Hollow area 53 Third image element 54 Marker 6 Onboard aircraft 60 Display control unit 61 Storage unit 62 Camera 63 Image recognition unit 64 Sensor unit 65 Distance/direction calculation unit 66 Command generation unit 67 Aircraft control signal transmission/reception unit 68 Video data wireless transmission/reception unit 69 Communication control unit

Claims (5)

unmanned aircraft and
and a display device that can be identified from the sky and that transmits a fixed point to the unmanned aircraft,
A first image element displayed on the display device to indicate the fixed point is a two-dimensional barcode including a hollow area in which no code is displayed;
A flight system having a nested structure in which a second image element similar to the first image element is displayed in a reduced size in the hollow area. The flight system according to claim 1, wherein the nested structure is repeated multiple times. 3. The flight system according to claim 1, wherein a marker indicating the fixed point is displayed at the center of the hollow area. The shape of the hollow region is similar to the outer shape of the first image element,
The flight system according to claim 1 or 2, wherein the outer shape of the second image element and the shape of the hollow region match. Equipped with a take-off and landing pad on which the unmanned aircraft can take off and land,
The display device is disposed on the takeoff and landing pad,
The flight system according to claim 1 or 2, wherein the fixed point is a landing point of the unmanned aircraft.

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