Unmanned Aerial Vehicle Control System

Abstract

To provide an unmanned flying body control system that includes two GPS receivers for receiving a radio wave from one artificial satellite.SOLUTION: An unmanned flying body control system includes: an unmanned flying body and an operation terminal 31 for remote-controlling; and a controller for controlling the unmanned flying body and the control terminal 31 with an operation instruction. The unmanned flying body includes: two GPS receivers 51, 52 for receiving a radio wave from one artificial satellite; and positional information acquisition means for acquiring positional information of a prescribed position in the middle of a flight route. The positional information acquisition means acquires positional information of the unmanned flying body on the basis of measurement values of the GPS receivers 51, 52.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an unmanned aerial vehicle control system that takes over remote control of an unmanned aerial vehicle. [Background technology]

[0002] Unmanned aerial vehicles (drones) controlled by a control terminal such as a controller are also used to transport relatively heavy cargo such as construction materials and tools. When the distance from the starting point to the destination is long, for example in mountainous or forested areas where it is difficult to ensure visibility for the entire journey, control is handed over to another person mid-way (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2017-74826 Summary of the Invention [Problem to be solved by the invention]

[0004] According to Patent Document 1, when a flight control signal from one control terminal is no longer received, the unmanned aerial vehicle enters a hovering state, and then, upon receiving a flight control signal from another control terminal, the unmanned aerial vehicle releases the hovering state and enters a flying state, thereby achieving a handover. However, separate communication is required between the operators of the one control terminal and the other control terminal at the time of the handover. However, Patent Document 1 makes no mention of communication regarding the timing of the handover. To ensure a smooth handover, simple and prompt communication between the operators is required. Furthermore, while GPS receivers have traditionally been used to obtain the location information of unmanned aerial vehicles, it has been necessary to receive radio waves from multiple satellites.

[0005] The problem that the present invention aims to solve is to provide an unmanned aerial vehicle control system that makes it possible to obtain position information of an unmanned aerial vehicle using radio waves from a single artificial satellite. [Means for solving the problem]

[0006] In order to solve the above problem, the unmanned aerial vehicle control system of the present invention is an unmanned aerial vehicle control system having an unmanned aerial vehicle, a control terminal for remotely controlling the unmanned aerial vehicle, and a control unit for controlling the unmanned aerial vehicle and the control terminal based on operation instructions, wherein the unmanned aerial vehicle has two GPS receivers for receiving radio waves from one artificial satellite and a position information acquisition means for acquiring position information of a predetermined position along its flight path, and the position information acquisition means acquires the position information of the unmanned aerial vehicle based on the measurement values ​​of the GPS receiver.

[0007] According to this configuration, since there are two GPS receivers that receive radio waves from one artificial satellite, it is possible to use a GPS receiver with a simple structure when obtaining position information of an unmanned aerial vehicle.

[0008] The unmanned aerial vehicle control system of the present invention may be configured to have other GPS receivers that receive radio waves from at least four artificial satellites, and the location information acquisition means may acquire the location information based on the measurement values ​​of the other GPS receivers.

[0009] With this configuration, location information is obtained from the measurement values ​​of other GPS receivers that receive radio waves from four artificial satellites, making it possible to use a GPS receiver with a simple structure and other GPS receivers when obtaining location information.

[0010] In the unmanned aerial vehicle control system according to the present invention, the position information acquisition means acquires the position information based on the measurement values ​​of the other GPS receiver or the measurement values ​​of the two GPS receivers and the measurement values ​​of the sensor mounted on the unmanned aerial vehicle.

[0011] With this configuration, location information can be obtained from measurements by the other GPS receiver that receives radio waves from four satellites, as well as from measurements by two GPS receivers installed at predetermined locations on the unmanned aerial vehicle, each receiving radio waves from one satellite, and from measurements by sensors installed on the unmanned aerial vehicle. The sensors include a barometric sensor and ultrasonic sensor that can measure altitude, as well as an acceleration sensor, angular velocity sensor (gyro sensor), and geomagnetic sensor that can measure the direction of movement, inclination, and orientation of the unmanned aerial vehicle. Utilizing the various sensors installed on the multicopter enables the use of a second GPS receiver with a simple structure to obtain location information. [Effects of the Invention]

[0012] According to the present invention, since two GPS receivers that receive radio waves from one artificial satellite are provided, it is possible to use GPS receivers with a simple structure when acquiring the position information of the unmanned aerial vehicle. When remote control of the unmanned aerial vehicle is taken over mid-flight, notification of the takeover is sent between the control terminals, so this can be done easily without providing a device configuration for the takeover on the unmanned aerial vehicle. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic perspective view of a multicopter, which is an unmanned aerial vehicle according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram of the multicopter shown in FIG. [Figure 3] FIG. 3 is a block diagram of the control terminal according to the embodiment of the present invention. [Figure 4] Figure 4 is a flow diagram showing the procedure for taking over remote control of a multicopter. [Figure 5] FIG. 5 is a schematic diagram illustrating the takeover of remote control of the multicopter shown in FIG. [Figure 6] FIG. 6 is a schematic explanatory diagram of how position information of the multicopter shown in FIG. 1 is acquired. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present invention will be described with reference to the drawings.

[0015] As shown in Figure 1, the unmanned aerial vehicle, a multicopter 11 (drone), has a main body 12 on which equipment such as a power supply and control devices are mounted, four rod-shaped arm sections 13 (13a, 13b, 13c, 13d) (hereinafter referred to as "arm sections 13") protruding in all directions from the main body 12, four drive units 15 (15a, 15b, 15c, 15d) (hereinafter referred to as "drive units 15") provided at the tips of the arm sections 13 (13a, 13b, 13c, 13d), four rotors 17 (17a, 17b, 17c, 17d) (hereinafter referred to as "rotor sections 17") provided at the upper ends of the drive units 15 (15a, 15b, 15c, 15d), and a pair of legs 18a, 18b provided on the bottom surface of the main body 12. Another GPS receiver 28 is provided in the center of the main body 12, and GPS receivers 51 and 52 are provided at both ends of the main body 12 at symmetrical positions.

[0016] The drive units 15 (15a, 15b, 15c, 15d) each include a motor 21 (21a, 21b, 21c, 21d) (simply referred to as "motor 21" as appropriate) that rotates and drives the rotors 17 (17a, 17b, 17c, 17d), and a drive controller 22 (22a, 22c, 22d) (simply referred to as "drive controller 22" as appropriate) that controls the rotation of the motor 21 (see FIG. 2). The rotors 17 are connected to the motor 21 via a rotating shaft (not shown). The motor 21 may be, for example, a servo motor. In this embodiment, the number of rotors 17 is four; however, this is not limited to four, and the number may be six, eight, or the like. However, an even number is required to maintain stable flight. This is because adjacent rotors 17 rotate in opposite directions, thereby canceling out the action and reaction caused by the rotational moment and stabilizing the attitude of the multicopter 11.

[0017] Main body 12, located in the center of multicopter 11, is a cylindrical box, and legs 18a, 18b provided on the bottom surface of main body 12 are made of approximately U-shaped members and serve as attachment points when multicopter 11 transports cargo. Materials used for multicopter 11 include synthetic resin, aluminum, and the like, and when particular strength and rigidity are required, CFRP (Carbon Fiber Reinforced Plastics) is used.

[0018] Next, the configuration of the multicopter 11 will be described with reference to the block diagram of Figure 2. The main body 12 of the multicopter 11 includes a communication unit 25 that transmits and receives signals to and from the control terminal 31 (31a, 31b: see Figure 3), a power source 26 (battery) that supplies power to the motor 21, etc., a camera 27 that captures images of the surroundings of the multicopter 11, another GPS receiver 28 that receives radio waves from artificial satellites to measure position information, GPS receivers 51 and 52, a sensor unit 30 that stores various sensors such as an acceleration sensor, a control unit 33 that controls the communication unit 25, the camera 27, the other GPS receiver 28, the GPS receivers 51 and 52, the sensor unit 30, etc., and a non-volatile memory storage unit 35 (e.g., flash memory, etc.) that stores programs for controlling various functions of the multicopter 11, measured data, etc. The drive control unit 22 included in the drive unit 15 receives instructions from the control unit 33 and controls the motor 21 to increase / decrease the rotation speed, start / stop, etc. The control unit 33 allows each drive control unit 22 (22a, 22b, 22c, 22d) to independently control the drive of each motor 21 (21a, 21b, 21c, 21d), thereby individually driving the rotors 17 (17a, 17b, 17c, 17d) and allowing the multicopter 11 to ascend, descend, turn left and right, hover, etc.

[0019] The control unit 33 is what is called a flight controller and includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), etc., and executes various controls according to various programs stored in the ROM or storage unit 35. The camera 27 may be an ordinary camera, an infrared camera, a stereo camera, etc. Images captured by the camera 27 are transmitted by the control unit 33 via the communication unit 25 to the control terminal 31 (see FIG. 3) and displayed on the display unit 55 (see FIG. 3) of the control terminal 31.

[0020] The other GPS receiver 28, located in the center of the main body 12 of the multicopter 11, receives radio waves from at least four satellites to acquire position information for the multicopter 11 (see FIG. 1). GPS receivers 51 and 52 (see FIG. 1), located at opposite ends of the main body 12, receive radio waves from one satellite and acquire position information for the multicopter 11 using measurements from the barometric pressure sensor, altitude sensor (ultrasonic sensor), acceleration sensor, angular velocity sensor (gyro sensor), and geomagnetic sensor of the sensor unit 30 (described later). For example, after initially acquiring position information using the other GPS receiver 30, use of the other GPS receiver 30 can be stopped, and subsequent position information can be acquired using the information received from the satellites by the GPS receivers 51 and 52 and the measurements acquired from the above-mentioned sensors. The control unit 33 and the other GPS receiver 28 constitute a position information acquisition means, or the control unit 33, the GPS receivers 51 and 52, and the sensor unit 30 constitute a position information acquisition means. The storage unit 35 that stores the program for acquiring location information and the acquired location information corresponds to the storage means.

[0021] As mentioned above, the sensor unit 30 includes a barometric pressure sensor, an altitude sensor (ultrasonic sensor), an acceleration sensor, an angular velocity sensor (gyro sensor), a geomagnetic sensor, and the like. The barometric pressure sensor detects changes in air pressure and can determine the drone's altitude, but since the barometric pressure sensor may not function properly due to weather conditions, an ultrasonic sensor is also used. The ultrasonic sensor detects the distance from the ground by emitting ultrasonic waves and measuring the time it takes for the waves to bounce back. The acceleration sensor detects the distance traveled by detecting acceleration, and the angular velocity sensor (gyro sensor) detects the number of times the aircraft rotates within a certain period of time. The geomagnetic sensor detects direction using magnetic force. The control unit 33 and the various sensors of the sensor unit 30 constitute a leveling means that ensures the unmanned aerial vehicle remains level.

[0022] Next, the device configuration of the control terminal 31 (31a, 31b) will be described with reference to FIG. 3. As shown in FIG. 3, the control terminal 31 includes a communication unit 56 that transmits and receives data to and from the communication unit 25 of the multicopter 11 to remotely control the multicopter 11, an operation unit 57 that controls the multicopter 11 via the communication unit 56, a display unit 55 that displays images captured by the camera 27 of the multicopter 11 and various instructions on a touch panel for operation, a switch unit 58 that issues transmission instructions for transmitting notification signals between the first control terminal 31a and the second control terminal 31b, a speaker 59 and an output circuit 60 that generate a ringtone when a notification signal is received, an indicator light 54 that lights up when a notification signal is received, a control unit 61 that controls these functions, and a memory unit 62 that stores programs for controlling and controlling each device, measurement data, etc. The control terminal 31 also includes a built-in battery (not shown) that serves as a power source.

[0023] The operation of the multicopter 11 using the operation unit 57 is performed, for example, by operating sticks (not shown) arranged on the left and right sides of the surface of the control terminal 31. Tilt the right stick up to "ascend," down to "descend," left to "move left," and right to "move right," while tilting the left stick up to "move forward," down to "move backward," left to "turn left," and right to "turn right." The multicopter 11 can be placed in a hovering state by "ascending" and slowly stopping the ascent, thereby balancing the lift and the gravity of the multicopter 11. Note that the hovering state can also be automatically set by operating the operation touch panel displayed on the display unit 55.

[0024] The screen of the display unit 55 displays not only the image captured by the camera 27 and the operation touch panel, but also the current position information (latitude, longitude, and altitude) of the flying multicopter 11. The displayed current position information can be stored in the memory unit 62 and / or the memory unit 35 of the multicopter 11 by a predetermined operation on the operation touch panel of the display unit 55. The switch unit 58 transmits a notification signal to the other control terminal 31 when operated during a takeover. The control terminal 31b that receives the notification signal generates a reception sound from the speaker 59 and also lights up the indicator light 54. It is possible to set the transmitting control terminal 31a that operates the switch unit 58 to also generate a transmission sound and light up the indicator light. The control unit 61, switch unit 58, and communication unit 56 constitute a notification signal transmitting / receiving means. The control unit 61, output circuit 60, and speaker 59 constitute a reception sound generating means, and the control unit 61 and indicator light 54 constitute a light up display means (reception and display means). Furthermore, the operation touch panel displayed on the display unit 55 and the control unit 61 constitute a predetermined position flight means and a position information acquisition instruction means. Operation (pressing, etc.) of the switch unit 58 gives a transmission instruction.

[0025] Next, the handover of control of the multicopter 11 will be described with reference to FIG. 4. Remote control of the multicopter 11 is initiated by the first control terminal 31a (S1). For example, when flying the multicopter 11 carrying cargo or the like from the base of a mountain to a site at the top, it is difficult for the pilot of the first control terminal to visually check the landing point at the top and the terrain near the top. Although the pilot can check images of the surrounding area captured by the camera 27 of the multicopter 11, stable flight and landing may be difficult if the terrain is complex. In such a case, by handing over control from the pilot at the base of the mountain to another pilot near the top, it is possible to land safely at the target point near the top by visual confirmation.

[0026] When the multicopter 11, which has been moved from the start point by the first control terminal 31a, reaches a predetermined handover point, the first control terminal 31a operates the switch unit 58 as a transmission instruction to notify the second control terminal 31b of the handover, and the control unit 61 transmits a notification signal to the first control terminal 31b (S2: notification signal transmitting / receiving means). In the second control terminal 31b, which receives this notification signal, the control unit 61 generates a ringtone from the speaker 59 via the output circuit 60 (received sound generating means) and also turns on the indicator light 54 (lighting display means). When the switch unit 58 as a transmission instruction is operated, the control unit 61 transmits a notification signal to the first control terminal 31a to confirm receipt (S3: notification signal transmitting / receiving means).

[0027] In the first control terminal 31a that has received the above-described reception confirmation notification signal, the control unit 61 generates a ringtone from the speaker 59 via the output circuit 60 (received sound generating means), turns on the indicator light 54 (lighting display means), and further stops remote control of the multicopter 11 (S4). In the second control terminal 31b that has transmitted the reception confirmation notification signal, remote control is quickly started after transmission (S5). This allows control of the multicopter 11 to be quickly taken over, minimizing flight disruptions and completing the remote control handover (S6). Note that, since a ringtone is generated and an indicator light is turned on when a notification signal is received, the reliability of communication with the receiving side is improved.

[0028] Next, handover using position information of intermediate points on the flight path will be described with reference to Figure 5. Take the example of transporting luggage using multicopter 11 from starting point S at the foot of a mountain to arrival point E at the top of the mountain. The luggage is loaded onto multicopter 11 at starting point S, and the multicopter is caused to ascend toward the top using first control terminal 31. As part of the flight route, relay point A is set in the air above starting point A (higher than the top), and relay point B is set in the air above arrival point E, proceeding horizontally from relay point A.

[0029] The position information (position coordinates) of relay points A and B is acquired by a preliminary flight before the actual cargo transport. The preliminary flight is conducted during the day when natural conditions are favorable, and the position information (position coordinates) of relay points A and B is acquired by appropriately selecting other GPS receivers 28, GPS receivers 51 and 52, various sensors, etc. The aircraft ascends from departure point S, and an arbitrary point slightly higher than the summit is set as relay point A. The control unit 33 acquires the position information (latitude, longitude, altitude) displayed on the display unit 55 through operation of the operation touch panel and stores it in the memory unit 62 (storage means) of the control terminal 31 and / or the memory unit 35 (storage means) of the multicopter 11 (position information acquisition instruction means, position information acquisition means). Similarly, the aircraft flies horizontally from relay point A, and acquires the position information of relay point B, which is located above arrival point E, and stores it in the memory unit 62 and / or the memory unit 35. During actual remote control, the position information of relay points A and B can be input as the flight route, and the control unit 33 enables the multicopter 11 to fly via relay points A and B (predetermined position flight means).

[0030] In this way, the position information of relay points A and B is obtained in advance during a preliminary flight (empty), so remote control can be performed based on the position information of relay points A and B even when the actual cargo transport is performed in bad weather, with poor visibility, or at night. The handover from the first control terminal 31a to the second control terminal 31b can also be performed at either relay point A or B. For example, the first control terminal 31a launches the multicopter 11 from the departure point S. Since the remote control uses the position information of relay points A and B, the multicopter 11 flies via relay points A and B. When the multicopter 11 reaches either relay point A or B, the first control terminal 31a transmits a notification signal for handover to the second control terminal 31b. The first control terminal 31a, upon receiving a confirmation notification signal from the second control terminal 31b that has received the notification signal, stops remote control. The second control terminal 31b, which transmitted the confirmation notification signal, then starts remote control, completing the handover.

[0031] By having the handover take place at either relay point A or B, the reliability of the handover operation is improved, enabling stable cargo transport flights. For example, in cases where visual flight by solo pilot is difficult, such as on mountain tops, at high altitudes, or in forested areas, remote flight using relay point position information makes handover easy even during night flights or flights in bad weather, and improves transport efficiency in cases where round-trip transport is required repeatedly.

[0032] Next, the acquisition of position information (latitude, longitude, altitude) using the GPS receivers 51 and 52 of the multicopter 11 will be described with reference to Fig. 6. As described above, the other GPS receivers 28 receive radio waves from at least four artificial satellites to acquire position information (position coordinates), whereas the GPS receivers 51 and 52 receive radio waves from one artificial satellite 71 and acquire the position information of the multicopter 11 using the measurement values ​​of various sensors mounted on the multicopter 11.

[0033] The GPS receivers 51 and 52 that receive radio waves from the artificial satellite 71 determine the distance between the artificial satellite 71 and the GPS receivers 51 and 52, respectively, from the position information of the artificial satellite 71 and the time difference. Since the distance between the GPS receivers 51 and 52 is known, the triangle formed by the artificial satellite 71 and the GPS receivers 51 and 52 and the altitude H of the multicopter 11 are determined using a barometric pressure sensor and an altitude sensor (ultrasonic sensor), and the position information (latitude, longitude, altitude) of the multicopter 11 is determined. Also, for example, only the position information of the departure point A shown in FIG. 5 is determined using the other GPS receiver 28, and then the position information of intermediate points on the way to the destination point E can be determined using the measurement values ​​of the GPS receiver, the barometric pressure sensor, the altitude sensor (ultrasonic sensor), the acceleration sensor, the angular velocity sensor (gyro sensor), and the geomagnetic sensor. In this way, instead of using other conventional GPS receivers 28, the position information (position coordinates) of the multicopter can be obtained using GPS receivers 51, 52 with simple device configurations and various sensors installed on them.

[0034] The multicopter 11 of this embodiment may need to transport a relatively heavy load to a location with a large elevation difference, and remote control is required that takes into account environments susceptible to natural phenomena such as wind. In addition to the normal flight program, it is necessary to maintain horizontality in the event that a heavy load becomes misaligned during flight. Based on the measured values ​​of the barometric pressure sensor, altitude sensor (ultrasonic sensor), acceleration sensor, angular velocity sensor (gyro sensor), and geomagnetic sensor, the control unit 33 of the multicopter 11 can maintain horizontality by controlling the rotation speed of each of the rotors 17 (17a, 17b, 17c, 17d) using the drive control units 22 (22a, 22b, 22c, 22d) in accordance with a horizontality maintenance program stored in the memory unit 35 (horizontal maintenance means).

[0035] Although the multicopter 11 according to this embodiment has four rotors, the number is not limited to four and may be six, eight, or the like. Furthermore, while the remote control is handed over between the first and second control terminals, the number of control terminals is not limited to two and may be three, four, or the like. Furthermore, the handover may be performed after the multicopter 11 is in a low-speed flight or hovering state. In this embodiment, the control unit 61 provided in each of the first and second control terminals 31a and 31b controls the transmission and reception of notification signals by the notification signal transmission / reception means and the reception and display by the reception and display means. However, the present invention is not limited to this and may also be controlled by, for example, a control unit of the multicopter 11 (unmanned aerial vehicle).

[0036] Although several embodiments and modifications of each part of the present invention have been described above, these embodiments and modifications of each part are presented as examples and are not intended to limit the scope of the invention. These novel embodiments described above can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and modifications are included within the scope and spirit of the invention, and are also included in the invention described in the claims. [Industrial Applicability]

[0037] As explained above, according to the unmanned aerial vehicle control system and unmanned aerial vehicle control method of the present invention, handover notifications are sent between control terminals, which has the advantage that the handover can be easily performed without providing a device configuration for the unmanned aerial vehicle, and therefore the system is useful as a control system and control method for an unmanned aerial vehicle that has an unmanned aerial vehicle and a control terminal that remotely controls the unmanned aerial vehicle. [Explanation of symbols]

[0038] 11 Multicopter (unmanned aerial vehicle) 12 Main body 13(13a, 13b, 13c, 13d) Arm part 15(15a, 15b, 15c, 15d) Drive unit 17(17a, 17b, 17c, 17d) Rotor 18a, 18b Legs 21(21a, 21b, 21c, 21d) Motor 22 (22a, 22b, 22c, 22d) Drive control unit 25 Communications Department 26 Power supply 27 Camera 28 Other GPS 30 Sensor unit 31 Control terminal 31a First control terminal 31b Second Control Terminal 33 Control Unit 35 Storage section 51, 52 GPS 54 Indicator light 55 Display section 56 Communications Department 57 Operation section 58 Switch section 61 Control Unit 62 Storage section 71 Satellite

Claims

[Claim 1] An unmanned aerial vehicle control system having an unmanned aerial vehicle, a control terminal that remotely controls the unmanned aerial vehicle, and a control unit that controls the unmanned aerial vehicle and the control terminal based on operation instructions, The unmanned aerial vehicle has two GPS receivers that receive radio waves from one artificial satellite, a position information acquisition means for acquiring position information of a predetermined position along the flight path; the location information acquisition means acquires location information of the unmanned aerial vehicle based on measurement values ​​of the GPS receiver, Furthermore, the unmanned aerial vehicle has another GPS receiver that receives radio waves from at least four artificial satellites, the location information acquisition means acquires the location information based on measurement values ​​of the other GPS receivers; Furthermore, in this unmanned aerial vehicle control system, after the location information acquisition means first acquires the location information based on the measurement values ​​of the other GPS receiver, it stops using the other GPS receiver and acquires subsequent location information based on the measurement values ​​of the two GPS receivers and the measurement values ​​of the sensor mounted on the unmanned aerial vehicle.

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