Location acquisition system and location acquisition method

Abstract

The system aims to simplify while accurately acquiring the position of the aircraft relative to the target landing site. [Solution] The system includes a first position detection unit that acquires the position of a moving object, a second position detection unit that acquires the position of a target landing point set on the object, a third position detection unit that acquires the position of an aircraft landing at the target landing point, and a control unit that acquires the positional relationship between the object, the target landing point, and the aircraft based on the detection results of the first, second, and third position detection units. The control unit acquires the relative position between the object and the aircraft based on the position of the object detected by the first position detection unit and the position of the aircraft detected by the third position detection unit, and acquires the positional relationship between the object and the target landing point as an offset position based on the position of the object detected by the first position detection unit and the position of the target landing point detected by the second position detection unit.

Description

Technical Field

[0001] The present disclosure relates to a position acquisition system and a position acquisition method.

Background Art

[0002] Conventionally, an automatic landing system for landing a vertical takeoff and landing aircraft on a landing target point provided on a ship has been known (see, for example, Patent Document 1). The automatic landing system for the vertical takeoff and landing aircraft of Patent Document 1 controls the vertical takeoff and landing aircraft so that the relative position between the vertical takeoff and landing aircraft and the landing target point becomes zero.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the automatic landing system for the vertical takeoff and landing aircraft of Patent Document 1, in the approach mode where the vertical takeoff and landing aircraft is away from the landing target point, the relative position is calculated based on the position of the vertical takeoff and landing aircraft acquired by the navigation device and the position of the ship acquired by the navigation device. On the other hand, in the hovering mode where the vertical takeoff and landing aircraft approaches the landing target point in the automatic landing system, the relative position is calculated based on the captured image of the landing target point captured by the camera provided on the vertical takeoff and landing aircraft. For this reason, there is a problem that a plurality of processes for calculating the relative position between the vertical takeoff and landing aircraft and the landing target point are required, and the system becomes complicated. On the other hand, in order to simplify the system, in the hovering mode, it is conceivable to calculate the relative position using the navigation device as in the approach mode. However, in this case, since the detection accuracy of the position decreases, it becomes difficult to land the vertical takeoff and landing aircraft accurately on the landing target point.

[0005] Therefore, the purpose of this disclosure is to provide a position acquisition system and a position acquisition method that can acquire the position of an aircraft and a target landing site with high precision while simplifying the system. [Means for solving the problem]

[0006] The position acquisition system disclosed herein comprises: a first position detection unit for acquiring the position of a moving object; a second position detection unit for acquiring the position of a target landing point set on the moving object; a third position detection unit for acquiring the position of an aircraft landing at the target landing point; and a control unit for acquiring the positional relationship between the moving object, the target landing point, and the aircraft based on the detection results of the first, second, and third position detection units. The control unit acquires the relative position between the moving object and the aircraft based on the position of the moving object detected by the first position detection unit and the position of the aircraft detected by the third position detection unit, and acquires the positional relationship between the moving object and the target landing point as an offset position based on the position of the moving object detected by the first position detection unit and the position of the target landing point detected by the second position detection unit.

[0007] The position acquisition method disclosed herein is a position acquisition method performed by a position acquisition system that acquires the positional relationship between the position of a moving body, the position of a target landing point set on the moving body, and the position of an aircraft landing at the target landing point, wherein the relative position between the moving body and the aircraft is acquired based on the position of the moving body and the position of the aircraft, and the positional relationship between the moving body and the target landing point is acquired as an offset position based on the position of the moving body and the position of the target landing point. [Effects of the Invention]

[0008] According to this disclosure, an aircraft can be suitably detached from a moving object such as a ship. [Brief explanation of the drawing]

[0009] [Figure 1]Figure 1 is a schematic diagram showing an example of a position acquisition system according to this embodiment. [Figure 2] Figure 2 is a flowchart of the position acquisition method according to this embodiment. [Figure 3] Figure 3 is an explanatory diagram relating to position acquisition according to this embodiment. [Figure 4] Figure 4 is a flowchart illustrating another example of the position acquisition method according to this embodiment. [Modes for carrying out the invention]

[0010] Embodiments relating to this disclosure will be described in detail below with reference to the drawings. However, these embodiments do not limit this disclosure. Furthermore, some components in the embodiments described below are substituted or substantially identical to those easily substituted by those skilled in the art. Moreover, the components described below can be combined as appropriate, and if there are multiple embodiments, each embodiment can be combined.

[0011] [This Circumstance] Figure 1 is a schematic diagram showing an example of a position acquisition system according to this embodiment. The position acquisition system 100 is a system that acquires the positional relationship between the aircraft 1 and the ship 5, and also a system that acquires the positional relationship between the ship 5 and the target landing point where the aircraft 1 will land.

[0012] Aircraft 1 is a rotary-wing aircraft (e.g., a helicopter, drone, etc.). In this embodiment, aircraft 1 is an unmanned aerial vehicle (UAV). Aircraft 1 can be any aircraft capable of moving forward, backward, sideways, turning, and hovering, and may be a manned aircraft. Aircraft 1 is equipped with a position acquisition system 100, and its flight is controlled based on the position information acquired by the position acquisition system 100.

[0013] The target landing point is located on the ship 5. Therefore, the aircraft 1 lands on the ship 5, which is a moving object on the water. However, the target landing point is not limited to the ship 5; it may also be located on a vehicle or other moving object on land, or on stationary equipment or the ground.

[0014] The position acquisition system 100 according to this embodiment acquires the positional relationship between the aircraft 1 and the mobile vessel 5, as well as the positional relationship between the vessel 5 and the target landing point on the vessel 5. As shown in Figure 1, the position acquisition system 100 is configured as a system that is installed across the aircraft 1, the vessel 5, and the portable position detection device 120. In this embodiment, the system is applied to the vessel 5 as the mobile object, but it may also be applied to land vehicles such as cars as the mobile object. First, the vessel 5 will be described.

[0015] (ship) As shown in Figure 1, the ship 5 is equipped with a navigation system 60, an RTK positioning processing unit (first position detection unit) 70, a data transmission device 80, and an operation display unit 90.

[0016] The navigation system 60 is, for example, an Inertial Navigation System (INS) (registered trademark) that acquires the attitude angles of the ship 5 in the pitch and roll directions, heading, speed, acceleration, and position coordinates in the Earth coordinate system. In this embodiment, the navigation system 60 is described in relation to an inertial navigation system, but it is not particularly limited, and any navigation system 60 may be used. In this embodiment, the navigation system 60 is an inertial navigation system that includes a GPS (Global Positioning System) in order to improve the accuracy of position measurement. In this embodiment, the navigation system is described in relation to an inertial navigation system that includes a GPS, but it is not particularly limited to a GPS, and any system that can measure position accurately may be used. For example, a quasi-zenith satellite system may be used, or a configuration that omits GPS, etc., is acceptable if the navigation system 60 alone can measure position accurately. In addition, the navigation system 60 may acquire at least some of the various data using sensors.

[0017] The RTK positioning processing unit 70 is included in the position acquisition system 100 described later, and is a positioning method using a satellite positioning system including artificial satellites. The RTK positioning processing unit 70 is RTK (Real Time Kinematic)-GPS. Based on the carrier wave phase data transmitted from the artificial satellites to the ship 5 with the positions of the artificial satellites as reference points, the position coordinates of the ship 5 are measured. RTK-GPS receives signals from a plurality of artificial satellites with receivers at two mobile stations. RTK-GPS exchanges information between the two receivers based on the signals received from the plurality of artificial satellites to correct the deviation and obtain high-precision position information. RTK-GPS can suppress the error within a few centimeters.

[0018] The data transmission device 80 is included in the position acquisition system 100 described later, and exchanges various signals with the data transmission device 40 mounted on the aircraft 1 through wireless communication. The data transmission device 80 transmits the position coordinates of the ship 5 measured by the RTK positioning processing unit 70 to the data transmission device 40.

[0019] The operation display unit 90 is a user interface for the operator on the ship 5 to grasp the control status and input various instructions. The instructions input by the operation display unit 90 are transmitted from the data transmission device 80 to the data transmission device 40. Also, the control status of the aircraft 1 is transmitted from the data transmission device 40 to the data transmission device 80. That is, the data transmission device 40 and the data transmission device 80 can perform two-way communication.

[0020] (Aircraft) Next, the aircraft 1 will be described. As shown in FIG. 1, the aircraft 1 includes a navigation device 20, a control unit 30, a data transmission device 40, and an RTK positioning processing unit (third position detection unit) 50.

[0021] The navigation device 20 is, like the navigation device 60, for example, an inertial navigation device including GPS. Note that the navigation device 20 may also be an inertial navigation device including GPS or the like, or an inertial navigation device omitting GPS or the like, and is not particularly limited. The navigation device 20 including GPS acquires the attitude angles in the pitch direction and roll direction of the aircraft 1, the nose azimuth, the airframe speed, the airframe acceleration, and the position coordinates in the earth coordinate system of the aircraft 1. Note that the navigation device 20 may have an attitude angle sensor that detects the attitude angle of the aircraft 1, a speed detection sensor that detects the airframe speed of the aircraft 1, an acceleration detection sensor that detects the airframe acceleration of the aircraft 1, and a sensor that detects the nose azimuth of the aircraft 1. The navigation device 20 outputs the acquired attitude angle, airframe speed, airframe acceleration, and position coordinates of the aircraft 1 to the control unit 30.

[0022] The control unit 30 includes, for example, an integrated circuit such as a CPU (Central Processing Unit). The control unit 30 has an induction calculation unit 34 and a flight control unit 36.

[0023] The induction calculation unit 34 calculates a control amount of the aircraft 1 for guiding the aircraft 1 to the target landing point. The control amount is a control amount for adjusting the airframe speed, attitude angle, change rate of the attitude angle, etc. of the aircraft 1. The induction calculation unit 34 calculates the relative coordinate position between the aircraft 1 and the target landing point in order to calculate the control amount. Specifically, the induction calculation unit 34 calculates, as the relative coordinate position, the relative position between the aircraft 1 and the target landing point and the relative altitude between the aircraft 1 and the target landing point. The induction calculation unit 34 also calculates the relative speed between the aircraft 1 and the target landing point. The relative position is the distance between the aircraft 1 and the target landing point of the ship 5 in the horizontal direction. When calculating the relative position between the aircraft 1 and the target landing point, the induction calculation unit 34 uses the relative position between the aircraft 1 and the ship 5 acquired by the position acquisition system 100 described later and the offset position between the ship 5 and the target landing point. The relative altitude is the distance between the aircraft 1 and the target landing point of the ship 5 in the vertical direction. The induction calculation unit 34 calculates the relative altitude to the landing target point based on the altitude of the aircraft 1 detected by the altitude sensor 25.

[0024] Furthermore, the guidance calculation unit 34 calculates the relative speed between the aircraft 1 and the target landing point. More specifically, the guidance calculation unit 34 calculates the relative speed between the aircraft 1 and the target landing point based on the relative position and the aircraft speed.

[0025] The guidance calculation unit 34 then calculates the control quantity using feedback control (e.g., PID control) based on the relative position, relative altitude, relative velocity, and aircraft acceleration. Note that the feedback control is not limited to PID control, but may also be P control, PI control, PD control, etc. The guidance calculation unit 34 outputs the calculated control quantity to the flight control unit 36.

[0026] The flight control unit 36 ​​controls each component of the aircraft 1 according to the control values ​​calculated by the guidance calculation unit 34 to make the aircraft 1 fly. The flight control unit 36 ​​controls the blade pitch angle, rotation speed, etc. of each rotor according to the control values ​​and adjusts the aircraft's speed, attitude angle, rate of change of attitude angle, etc. As a result, the aircraft 1 is guided to the target landing point. In this embodiment, the guidance calculation unit 34 is described as a separate functional unit from the flight control unit 36, but the flight control unit 36 ​​and the guidance calculation unit 34 may be an integrated functional unit. That is, the flight control unit 36 ​​may perform the processing of the guidance calculation unit 34.

[0027] The RTK positioning processing unit 50, like the RTK positioning processing unit 70 described above, uses a positioning method that includes a satellite positioning system. The RTK positioning processing unit 50 is RTK (Real Time Kinematic)-GPS, and uses the position of the satellite as a reference point to measure the position coordinates of the aircraft 1 based on carrier phase data transmitted from the satellite to the aircraft 1.

[0028] The data transmission device 40, like the data transmission device 80 mentioned above, is included in the position acquisition system 100 described later, and exchanges various signals with the data transmission device 80 mounted on the ship 5 via wireless communication.

[0029] (Location acquisition system) Next, the position acquisition system 100 will be described. The position acquisition system 100 comprises an RTK positioning processing unit 50 and a data transmission device 40 of the aircraft 1, an RTK positioning processing unit 70 and a data transmission device 80 of the ship 5, and a portable position detection device 120.

[0030] The position detection device 120 is installed at the target landing point on the ship 5. The position detection device 120 includes an operation button 121, an RTK positioning processing unit (second position detection unit) 122, and a data transmission device (communication unit) 123.

[0031] Operation button 121 is a user interface used by operators on board the vessel 5. Operation button 121 is a button that is operated to acquire the position of the position detection device 120.

[0032] The RTK positioning processing unit 122, like the RTK positioning processing units 50 and 70 described above, uses a satellite positioning system including artificial satellites for positioning. The RTK positioning processing unit 122 is RTK (Real Time Kinematic)-GPS, and uses the position of the artificial satellite as a reference point to measure the position coordinates of the position detection device 120, that is, the position coordinates of the target landing point, based on carrier phase data transmitted from the artificial satellite to the position detection device 120.

[0033] The data transmission device 123, like the data transmission devices 40 and 80 described above, exchanges various signals wirelessly with the data transmission devices 40 and 80 mounted on the aircraft 1 and ship 5. The data transmission device 123 transmits the position coordinates of the target landing point measured by the RTK positioning processing unit 122 to the data transmission device 80.

[0034] (Position acquisition method) Next, the position acquisition method performed by the position acquisition system 100 according to this embodiment will be described with reference to Figures 2 and 3. Figure 2 is a flowchart of the position acquisition method according to this embodiment. Figure 3 is an explanatory diagram of the position acquisition according to this embodiment. The position acquisition method is a method for acquiring the offset position between the ship 5 and the target landing point P, which is necessary to calculate the relative position between the aircraft 1 and the target landing point P. In this embodiment, the position acquisition method is performed by the position detection device 120, and therefore the position detection device 120 functions as the control unit of the position acquisition system 100.

[0035] First, in the position acquisition method, a position detection device 120 is installed at the target landing point P. Next, the position detection device 120 determines whether or not the operation button 121 has been operated (step S1). If the position detection device 120 determines that the operation button 121 has not been operated (step S1: No), it repeats step S1 until the operation button 121 is operated. On the other hand, if the position detection device 120 determines in step S1 that the operation button 121 has been operated (step S1: Yes), it acquires the position information (position coordinates) of the target landing point P (step S3).

[0036] After step S3 is executed, the position detection device 120 acquires the position information (position coordinates) of the vessel 5 (step S5). In step S5, the position detection device 120 acquires the position coordinates of the vessel 5, which were acquired by the RTK positioning processing unit 70 of the vessel 5, via the data transmission device 80 and the data transmission device 123. Then, from the acquired position information of the vessel 5 and the acquired position information of the target landing point P, the position detection device 120 acquires the offset position (relative position), which is the distance between the vessel 5 and the target landing point P, as shown in Figure 3 (step S6). After this, the position detection device 120 outputs the acquired offset position toward the aircraft 1 (step S7). In step S7, the position detection device 120 transmits the acquired offset position toward the aircraft 1 via the data transmission device 123 and the data transmission device 40. After step S7 is executed, the position acquisition system 100 terminates the processing related to the position acquisition method.

[0037] As shown in Figure 3, the aircraft 1 acquires the relative position between the aircraft 1 and the target landing point P on the ship 5 by offsetting its position based on the acquired offset position (the relative position between the ship 5 and the target landing point P), and then performs flight control based on this relative position.

[0038] In this embodiment, the offset position is output from the position detection device 120 toward the aircraft 1, but the system is not particularly limited to this configuration. For example, the offset position may be acquired in the ship 5 and output from the ship 5 toward the aircraft 1, or the offset position may be acquired in the aircraft 1. In these cases, the control units 30 provided in the aircraft 1 and the ship 5 function as control units for the position acquisition system 100.

[0039] Here, when aircraft 1 lands at target landing point P on ship 5, communication interference may occur at target landing point P due to structures around target landing point P and the satellites used in RTK-GPS. For this reason, the position detection device 120 may evaluate the communication status with the satellite positioning system, including multiple satellites, at target landing point P. Furthermore, if there are satellites with unstable communication, the position detection device 120 may detect the position of the target landing point without using the positioning information of the unstable satellites. Below, with reference to Figure 4, another example of a position acquisition method performed by the position acquisition system 100 according to this embodiment will be described. Figure 4 is a flowchart relating to another example of a position acquisition method according to this embodiment. In Figure 4, the communication status with the satellite positioning system is evaluated after the execution of step S1. In the following description, parts that are the same as those in Figure 2 will be omitted from the explanation.

[0040] In step S1, the position detection device 120 determines that the operation button 121 has been operated (step S1: Yes) and then determines whether there are any satellites of the satellite positioning system that cause unstable communication (step S2). If the position detection device 120 determines that there are no satellites of the satellite positioning system that cause unstable communication (step S2: Yes), it proceeds to step S3. On the other hand, if the position detection device 120 determines in step S2 that there are satellites of the satellite positioning system that cause unstable communication (step S2: No), it excludes the satellites of the satellite positioning system that cause unstable communication (step S4), and then executes step S3.

[0041] As described above, the position acquisition system 100 and position acquisition method described in this embodiment can be understood, for example, as follows.

[0042] The position acquisition system 100 according to the first embodiment includes a first position detection unit (RTK positioning processing unit 70) for acquiring the position of a moving object, a second position detection unit (RTK positioning processing unit 122) for acquiring the position of a target landing point set for the moving object, a third position detection unit (RTK positioning processing unit 50) for acquiring the position of an aircraft 1 that lands at the target landing point, and a control unit that acquires the positional relationship between the moving object, the target landing point, and the aircraft based on the detection results of the first position detection unit, the second position detection unit, and the third position detection unit. The control unit acquires the relative position between the moving object and the aircraft based on the position of the moving object detected by the first position detection unit and the position of the aircraft 1 detected by the third position detection unit, and acquires the positional relationship between the moving object and the target landing point as an offset position based on the position of the moving object detected by the first position detection unit and the position of the target landing point detected by the second position detection unit.

[0043] This configuration simplifies the system by performing position acquisition using a position detection unit, and by using an offset position, the positions of aircraft 1 and the target landing site can be acquired with high accuracy.

[0044] In a second embodiment, in the position acquisition system 100 according to the first embodiment, the moving body is a ship.

[0045] This configuration allows for highly accurate acquisition of the positions of the target landing point on the moving vessel 5 and the aircraft 1.

[0046] In a third embodiment, in the position acquisition system 100 according to the first or second embodiment, each of the first position detection unit, the second position detection unit, and the third position detection unit includes an RTK-GPS.

[0047] With this configuration, by using a high-precision RTK-GPS, the positions of aircraft 1 and the target landing site can be obtained with greater accuracy.

[0048] In a fourth embodiment, in the position acquisition system 100 according to the third embodiment, the second position detection unit evaluates the communication status with a satellite positioning system including multiple satellites at the target landing site, and if there is a satellite with unstable communication, the position of the target landing site is detected without using the positioning information of the unstable satellite.

[0049] This configuration allows for the detection of the target landing site's position while excluding satellites with unstable communications, thereby suppressing a decrease in the accuracy of position detection at the target landing site.

[0050] In a fifth embodiment, in a position acquisition system 100 according to any one of the first to fourth embodiments, the second position detection unit is provided on a portable position detection device 120, the position detection device 120 includes an operation unit (operation button 121), the second position detection unit which acquires position information based on the operation of the operation unit, and a communication unit (data transmission device 123) which transmits the position information acquired by the second position detection unit to at least one of the moving object and the aircraft 1.

[0051] With this configuration, the position detection device 120 can be easily installed at the target landing site, making it easy to obtain the position of the target landing site.

[0052] A position acquisition method according to the sixth embodiment is a position acquisition method performed by a position acquisition system that acquires the positional relationship between the position of a moving body, the position of a target landing point set on the moving body, and the position of an aircraft landing at the target landing point, wherein the relative position between the moving body and the aircraft is acquired based on the position of the moving body and the position of the aircraft, and the positional relationship between the moving body and the target landing point is acquired as an offset position based on the position of the moving body and the position of the target landing point.

[0053] This configuration simplifies the system by performing position acquisition of both relative and offset positions, and by using the offset position, the position of aircraft 1 relative to the target landing site can be acquired with high accuracy. [Explanation of Symbols]

[0054] 1 aircraft 5 Ships 20 Navigation equipment 30 Control Unit 34 Guidance calculation section 36 Flight Control Unit 40 Data transmission device 50 RTK positioning processing unit 60 Navigation equipment 70 RTK positioning processing unit 80 Data transmission device 90 Operation display section 100 Location Acquisition System 120 Position detection device 121 Operation Buttons 122 RTK positioning processing unit 123 Data transmission device

Claims

1. A first position detection unit that acquires the position of a moving object, A second position detection unit acquires the position of the target landing point set for the moving body, A third position detection unit that acquires the position of the aircraft landing at the aforementioned target landing point, The system includes a control unit that acquires the positional relationship between the moving object, the target landing point, and the aircraft based on the detection results of the first position detection unit, the second position detection unit, and the third position detection unit, The control unit, Based on the position of the moving body detected by the first position detection unit and the position of the aircraft detected by the third position detection unit, the relative position between the moving body and the aircraft is obtained. A position acquisition system that acquires the positional relationship between the moving object and the target landing point as an offset position based on the position of the moving object detected by the first position detection unit and the position of the target landing point detected by the second position detection unit.

2. The position acquisition system according to claim 1, wherein the moving body is a ship.

3. The position acquisition system according to claim 1, wherein each of the first position detection unit, the second position detection unit, and the third position detection unit includes an RTK-GPS.

4. The position acquisition system according to claim 3, wherein the second position detection unit evaluates the communication status with a satellite positioning system including multiple satellites at the target landing site, and if there is a satellite with unstable communication, it detects the position of the target landing site without using the positioning information of the unstable satellite.

5. The second position detection unit is provided in a portable position detection device. The position detection device is, Control panel and The second position detection unit acquires position information based on the operation of the aforementioned operation unit, The position acquisition system according to claim 1, further comprising a communication unit that transmits position information acquired by the second position detection unit to at least one of the moving object and the aircraft.

6. A position acquisition method performed by a position acquisition system that acquires the positional relationship between the position of a moving object, the position of a target landing point set on the moving object, and the position of an aircraft landing at the target landing point, Based on the position of the moving body and the position of the aircraft, the relative position between the moving body and the aircraft is obtained. A position acquisition method that acquires the positional relationship between the moving body and the target landing point as an offset position, based on the position of the moving body and the position of the target landing point.

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