JP2019039696A - Unmanned air vehicle and positioning method by unmanned air vehicle - Google Patents

Abstract

To provide an unmanned air vehicle and a positioning method by the unmanned air vehicle capable of efficiently performing electro-magnetic wave positioning from a quasi-zenith satellite.SOLUTION: An unmanned air vehicle 1 comprises electromagnetic wave receiving means for receiving positioning electromagnetic waves from a navigation satellite 202A or the like and a quasi-zenith satellite 204, positioning means for performing positioning using the positioning electromagnetic waves, and electromagnetic wave selection means for performing positioning using positioning electromagnetic waves from the quasi-zenith satellite 204 among navigation satellites when predetermined conditions are satisfied.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an unmanned air vehicle and a positioning method using the unmanned air vehicle.

  Conventionally, the use of a small unmanned air vehicle (also called “drone”) has been proposed. A technique for taking an image using such a drone has been proposed (for example, Patent Document 1).

JP 2006-27331 A

  By the way, when a drone performs a service (mission) such as image shooting, it is necessary to know the position of the drone itself. The drone measures the position of the drone itself using radio waves from a satellite such as GPS (Global Positioning System). If a quasi-zenith satellite is located in the sky in Japan, positioning can be performed with higher accuracy by performing positioning using radio waves from the quasi-zenith satellite. However, since the capacity of the battery (battery) that can be mounted on the drone is limited, there is a problem that if positioning is always performed using radio waves from the quasi-zenith satellite, the battery is consumed quickly.

  The present invention is an attempt to solve such a problem, and an object thereof is to provide an unmanned air vehicle capable of efficiently performing positioning using radio waves from a quasi-zenith satellite and a positioning method using the unmanned air vehicle. To do.

  The first invention is a radio wave receiving means for receiving positioning radio waves from navigation satellites, a positioning means for performing positioning using the positioning radio waves, and when a predetermined condition is satisfied, An unmanned aerial vehicle having radio wave selection means for positioning using the positioning radio wave from the quasi-zenith satellite.

  According to the configuration of the first invention, the unmanned air vehicle can receive the positioning radio wave from the quasi-zenith satellite only when the predetermined condition is satisfied. Positioning can be performed using radio waves.

  According to a second aspect of the present invention, in the configuration of the first aspect of the invention, the predetermined condition is that the unmanned air vehicle is located in a predetermined region.

  A third invention is an unmanned aerial vehicle in the configuration of the second invention, wherein the predetermined area is a city center and / or a mountain area.

  According to a fourth aspect of the present invention, in the configuration of the first aspect of the invention, satellite direction calculation means for calculating a direction of each navigation satellite based on the unmanned air vehicle based on orbit information of the navigation satellite, and each navigation system Obstacle determining means for determining whether or not there is an obstacle that prevents the positioning radio wave from reaching the unmanned air vehicle in the direction of a satellite, and the predetermined condition is the quasi-zenith that can be used for positioning. An unmanned aerial vehicle in which the number of navigation satellites other than satellites is equal to or less than a predetermined number.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the invention, there is provided a predicting unit that predicts whether or not the predetermined condition is satisfied after a predetermined time. It is an unmanned aerial vehicle according to the prediction result of the prediction means.

  A sixth invention is a positioning method by an unmanned air vehicle having radio wave receiving means for receiving positioning radio waves from a navigation satellite and positioning means for performing positioning using the positioning radio waves, and a predetermined method It is a positioning method by an unmanned aerial vehicle having a radio wave selection step of positioning using the positioning radio wave from the quasi-zenith satellite among the navigation satellites when the condition is satisfied.

  According to the present invention, positioning can be performed efficiently using radio waves from a quasi-zenith satellite.

It is the schematic which shows operation | movement of the unmanned air vehicle which concerns on 1st embodiment of this invention. It is the schematic which shows an unmanned air vehicle. It is a figure which shows the functional block of an unmanned air vehicle. It is the schematic which shows an example of topographical data. It is a flowchart which shows operation | movement of an unmanned air vehicle. It is the schematic which shows operation | movement of the unmanned air vehicle of 2nd embodiment. It is the schematic which shows an example of the topography data which the unmanned air vehicle of 2nd embodiment has. It is a flowchart which shows operation | movement of an unmanned air vehicle.

  Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail. In the following description, the same reference numerals are given to the same components, and the description thereof is omitted or simplified. Note that description of configurations that can be appropriately implemented by those skilled in the art will be omitted, and only the basic configuration of the present invention will be described.

<First embodiment>
As shown in FIG. 1, the positioning system of the present embodiment includes an unmanned air vehicle (hereinafter referred to as “unmanned aircraft 1”) and a base station 100 that can communicate with the unmanned aircraft 1. The drone 1 can receive and measure positioning radio waves from a plurality of navigation satellites 202A, 202B, 202C, 202D, 202E, 202F, 202G, and 202H. The navigation satellite 202A or the like is a GPS (Global Positioning System) satellite. Hereinafter, the navigation satellite 202A or the like is referred to as “GPS satellite 202A or the like”. The drone 1 can receive the positioning radio wave from the quasi-zenith satellite 204 and perform positioning in combination with the positioning radio wave received from the GPS satellite 202A or the like. Here, the quasi-zenith satellite is an artificial satellite that takes a quasi-zenith orbit, that is, an orbit that stays above a specific area for a long time. In the present embodiment, the following description will be given on the assumption that one specific area is the territory of Japan and the drone 1 can always receive radio waves from the quasi-zenith satellite 204. The drone 1 is an example of an unmanned air vehicle. The GPS satellite 202A and the like and the quasi-zenith satellite 204 are examples of navigation satellites. The quasi-zenith satellite 204 is an example of a quasi-zenith satellite.

The drone 1 normally receives only positioning radio waves from the GPS satellite 202A or the like, and performs positioning using the positioning radio waves from the quasi-zenith satellite 204 when a predetermined condition is satisfied. It has become. The predetermined condition is, for example, a case where the drone 1 is located in a predetermined area.
The predetermined area is, for example, the city center A1 or the mountain area A2 in FIG. For stable positioning, it is desirable to receive positioning radio waves from eight or more GSP satellites 202A or the like. However, in city center A1 or mountainous area A2, eight or more GSP satellites 202A or the like are received. Since there is a high possibility that positioning radio waves from the satellite cannot be received, positioning radio waves from the quasi-zenith satellite 204 are used together for positioning.

  As shown in FIG. 2, the drone 1 has a housing 2. The casing 2 includes a computer that controls each part of the drone 1, an autonomous flight device, a wireless communication device, a positioning device that uses positioning radio waves from a navigation satellite, an inertial sensor, an atmospheric pressure sensor, a battery, and the like. . Further, the information acquisition unit 10 is disposed in the housing 2 via the fixing device 12. The information acquisition unit 10 includes a camera 10. The fixing device 12 is a three-axis fixing device (so-called gimbal) that can minimize blurring of an image captured by the camera 10 and can control the optical axis of the camera 10 in an arbitrary direction.

  A round bar-like arm 4 is connected to the housing 2. A motor (not shown) is connected to each arm 4, and a propeller 6 is connected to each motor.

  A protective frame 8 is connected to the arm 4 to prevent the propeller 6 from coming into direct contact with an external object. The arm 4 and the protective frame 8 are made of, for example, carbon fiber reinforced plastic, and are lightweight while maintaining strength.

  FIG. 3 is a diagram illustrating a functional configuration of the drone 1. As shown in FIG. 3, the drone 1 includes a CPU (Central Processing Unit) 50, a storage unit 52, a wireless communication unit 54, a satellite positioning unit 56, an inertial sensor unit 58, a drive control unit 60, an image processing unit 62, and And a power supply unit 68.

  The drone 1 can communicate with the base station 100 by the wireless communication unit 54. The drone 1 receives an instruction such as starting from the base station 100 by the wireless communication unit 54.

  The drone 1 can measure the position of the drone 1 itself by the satellite positioning unit 56 and the inertial sensor unit 58. The satellite positioning unit 56 basically receives radio waves from four or more GPS satellites 202A or the like and / or the quasi-zenith satellite 204 and measures the position of the drone 1. The inertial sensor unit 58 measures the position of the drone 1 by accumulating the movement of the drone 1 from the starting point using, for example, an acceleration sensor and a gyro sensor. The position information of the drone 1 itself is used for determining the movement route of the drone 1 and for autonomous movement, and also for linking image data photographed by the image processing unit 62 with coordinates (position). Further, it is used to determine whether or not to perform positioning using positioning radio waves from the quasi-zenith satellite 204.

  The image processing unit 62 allows the drone 1 to operate the camera 10 and acquire an external image.

  By the drive control unit 60, the drone 1 controls the rotation of each motor (not shown) connected to each propeller 6 to control the posture such as vertical movement, air suspension, and tilt. .

  The power supply unit 68 is a replaceable rechargeable battery, for example, and supplies power to each unit of the drone 1.

  The storage unit 52 stores various data and programs necessary for autonomous movement, such as data indicating a movement plan for autonomous movement from the starting point to the target position, and information indicating the topography, shape, and structure position of the planned work area. In addition, the following programs are stored.

  The storage unit 52 stores a flight control program and a radio wave selection program. The CPU 50 and the radio wave selection program are examples of radio wave selection means.

  The drone 1 controls autonomous flight of the drone 1 by a flight control program. Specifically, the drone 1 adjusts the output of each motor (not shown) connected to each propeller 6 to fly in a predetermined route and altitude.

  The drone 1 performs positioning using the positioning radio wave from the quasi-zenith satellite 204 when a predetermined condition is satisfied by the above-described radio wave selection program. The predetermined condition is that the drone 1 is located within a predetermined area. The predetermined area is, for example, a city center or a mountain area (see FIG. 1).

  The radio wave selection program includes terrain information (see FIG. 4). The terrain information is obtained by dividing a certain geographical range by latitude Lo and longitude La, and describing the characteristics of each division. Each section is, for example, 100 m (meters) square. The topographic information is created in advance.

  The drone 1 continuously measures the position of the drone 1 itself by the satellite positioning unit 56 and the inertial sensor unit 58, and the positions thereof are the area A 1 (see FIGS. 1 and 4) and the area A 2 (see FIGS. 1 and 4). 4), the positioning is performed using the positioning radio wave from the quasi-zenith satellite 204. For example, in the area A1, positioning is performed using positioning radio waves from seven satellites among the GPS satellites 202A and the like and positioning radio waves from the quasi-zenith satellite 204.

  Even if the number of GPS satellites 202A and the like that can enter the area A1 and can be used for positioning becomes 7 or less, the position immediately before entering the area A1 has 8 or more GPS satellites 202A and the like, and the reliability is high. For this reason, it is possible to determine whether or not the drone 1 has entered the region A1 by combining the positioning result immediately before entering the region A1 and the output from the inertial sensor unit 58.

  The drone 1 may always receive a positioning radio wave from the quasi-zenith satellite 204 and use it for positioning when a predetermined condition is satisfied. Alternatively, when the predetermined condition is not satisfied, the radio wave from the quasi-zenith satellite 204 is not received, and when the predetermined condition is satisfied, the radio wave from the quasi-zenith satellite 204 is received and used for positioning. May be.

  Hereinafter, the operation of the drone 1 will be outlined with reference to FIG. The drone 1 starts when receiving a start instruction from the base station 100 (step ST1 in FIG. 5). Subsequently, the drone 1 receives a positioning radio wave from the GPS satellite 202A or the like and starts positioning (step ST2). The drone 1 determines whether or not the position of the drone 1 is within a predetermined area (step ST3), and if it is within the predetermined area, performs positioning using the positioning radio wave from the quasi-zenith satellite 204 (step ST4). ). Step ST4 is an example of a radio wave selection step. Subsequently, the drone 1 operates the camera 10 to perform a task such as shooting, and determines whether the task is completed (step ST5). If it is determined that the mission is completed, the drone 1 returns to the base station 100 (step ST6).

<Second Embodiment>
The second embodiment will be described with reference to FIGS. 6 and 7 for differences from the first embodiment. Descriptions common to the first embodiment are omitted.

  The unmanned aerial vehicle 1A of the second embodiment calculates the direction of each GPS satellite 202A and the like based on the orbit information of each GPS satellite 202A and the like. Then, it is determined whether or not there are obstacles that prevent the positioning radio waves from reaching the drone 1A in the directions of the respective GPS satellites 202A, and the number of GPS satellites 202A and the like that are present and can be used for positioning is determined. If the number is less than the predetermined number, positioning is performed using positioning radio waves from the quasi-zenith satellite 204.

  For example, if the position of the GPS satellite 202A calculated based on the orbit information is the position indicated by C1 in FIG. 6 and the drone 1A is positioned at the position B1, there is no obstacle, but the position of the GPS satellite 202A is C2. If the drone 1A is located at the position B2, the obstacle is present. The drone 1A determines whether or not the obstacle exists based on the positions after a predetermined time, not the current positions of the drone 1A and the GPS satellite 202A. The drone 1 estimates the position of the GPS satellite 202A or the like after a predetermined time with reference to the orbit information and time information of the GPS satellite 202A or the like. The drone 1A also estimates the position of the drone 1A itself after a predetermined time from the current flight speed and flight direction of the drone 1A itself, for example. The term “after the predetermined time” means, for example, 5 seconds (s) after the present time. For example, it is assumed that the drone 1A is currently located at the position B1 in FIG. 6 and is located at the position B2 after 5 seconds (s), and the position after 5 seconds (s) of the GPS satellite 202A is C2. Then, there is a disability in 5 seconds (s). For this reason, the drone 1A switches to positioning using the quasi-zenith satellite 204 in 5 seconds (s). The drone 1A continuously predicts the position of the GPS satellite 202A and the like after 5 seconds (s) and the position of the drone 1A itself. If it is predicted that the drone 1 </ b> A is disabled after 5 seconds (s) and the number of GPS satellites 202 </ b> A and the like that can be used for positioning is 7 or less, the quasi-zenith satellite 204 when 5 seconds (s) elapses. Positioning is also performed using radio waves for positioning.

  The storage unit 52 (see FIG. 3) of the drone 1A stores a satellite direction calculation program and an obstacle determination program. The CPU 50 and the satellite direction calculation program are examples of satellite direction calculation means. The CPU 50 and the obstacle determination program are examples of obstacle determination means.

  The drone 1A calculates the direction of each GPS satellite 202A and the like after a predetermined time based on the orbit information of each GPS satellite 202A and the like by a satellite direction calculation program. Here, after a predetermined time is, for example, after 5 seconds (s).

  The drone 1A determines whether there is a obstacle that prevents the positioning radio wave from reaching the drone 1A in the direction of each GPS satellite 202A or the like by the obstacle determination program. The drone 1 </ b> A performs positioning using the positioning radio waves from the quasi-zenith satellite 204 when the number of GPS satellites 202 </ b> A and the like that can be used for positioning is less than a predetermined number by the radio wave selection program. The predetermined number or less is, for example, 7 or less. That is, when the number of GPS satellites 202A and the like that can be used for positioning is seven or less, positioning is performed using radio waves for positioning from the quasi-zenith satellite 204 together.

  FIG. 7 is an example of terrain information included in the obstacle determination program of the drone 1A. As shown in FIG. 7, the terrain information is obtained by dividing a certain geographical range by latitude Lo and longitude La and describing the characteristics of each division. Each section is, for example, 100 m (meters) square. The terrain information includes information indicating the altitude of each section. For example, in the area A1, the altitude of a certain section is H1 (for example, 100 meters), and the altitude of another certain section is H4 (for example, 200 meters). Even in the area A1, since the altitudes are various, the number of the GPS satellites 202A and the like that the unmanned aircraft 1A can use for positioning is different. Topographic information including altitude is created in advance.

  In the area A1, the number of GPS satellites 202A and the like that can be used for positioning may be 7 or more. Conversely, outside the area A1, the number of GPS satellites 202A and the like that can be used for positioning is 7 or less. There can be. In this regard, the drone 1A always confirms the number of GPS satellites 202A and the like that can be used for positioning in the future by the radio wave selection program. Regardless of whether or not the drone 1A is located in the area A1, the GPS satellite 202A or the like that can be used for positioning in order to perform positioning with radio waves from the eight or more GPS satellites 202A or the like and / or the quasi-zenith satellite 204 It is determined whether or not the positioning radio wave from the quasi-zenith satellite 204 is used together.

  Hereinafter, the operation of the drone 1A will be outlined with reference to FIG. The drone 1A starts upon receiving a start instruction from the base station 100 (step ST1 in FIG. 8). Subsequently, the drone 1 receives a positioning radio wave from the GPS satellite 202A or the like and starts positioning (step ST2). The drone 1 determines whether or not a predetermined condition is satisfied after a predetermined time (step ST3A). For example, the time after the predetermined time is 5 seconds (s). The predetermined condition is, for example, a GPS satellite 202A that can be used for positioning because there is an obstacle that prevents the positioning radio wave from reaching the unmanned aircraft 1A between the position of the GPS satellite 202A and the like and the unmanned aircraft 1A after a predetermined time. The number of etc. is 7 or less. If it is determined that the predetermined condition is satisfied after a predetermined time, the drone 1A performs positioning using the positioning radio wave from the quasi-zenith satellite 204 when the predetermined time has elapsed (step ST4A). Step ST4A is an example of a radio wave selection step. Subsequently, the drone 1 operates the camera 10 to perform a task such as shooting, and determines whether the task is completed (step ST5). If it is determined that the mission is completed, the drone 1 returns to the base station 100 (step ST6).

  Note that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within a scope in which the object of the present invention can be achieved are included in the present invention.

1, 1A Unmanned aerial vehicle (Drone)
2 Housing 10 Camera 100 Base station

Claims (6)

Radio wave receiving means for receiving positioning radio waves from navigation satellites;
Positioning means for performing positioning using the positioning radio wave;
A radio wave selection means for performing positioning using the positioning radio wave from a quasi-zenith satellite among the navigation satellites when a predetermined condition is satisfied;
Unmanned aerial vehicle with. The predetermined condition is that the unmanned air vehicle is located within a predetermined region.
The unmanned aerial vehicle according to claim 1. The predetermined area is a city center and / or a mountain area.
The unmanned aerial vehicle according to claim 2. Satellite direction calculation means for calculating the direction of each navigation satellite based on the unmanned air vehicle based on orbit information of the navigation satellite;
Obstacle judging means for judging whether or not there is a obstacle that prevents the positioning radio waves from reaching the unmanned air vehicle in the direction of each navigation satellite;
Have
The predetermined condition is that the number of navigation satellites other than the quasi-zenith satellite that can be used for positioning is equal to or less than a predetermined number.
The unmanned aerial vehicle according to claim 1. Predicting means for predicting whether or not the predetermined condition is satisfied after a predetermined time;
The radio wave selection means follows the prediction result of the prediction means,
The unmanned aerial vehicle according to any one of claims 1 to 4. A positioning method by an unmanned air vehicle having radio wave receiving means for receiving positioning radio waves from a navigation satellite, and positioning means for performing positioning using the positioning radio waves,
A radio wave selection step of performing positioning using the positioning radio wave from a quasi-zenith satellite among the navigation satellites when a predetermined condition is satisfied;
Positioning method by unmanned air vehicle.