Mooring aircraft movement following device and control method

Abstract

The invention discloses a moored aircraft movement following device which comprises an aircraft measuring unit and a ground measuring unit, the aircraft measuring unit is connected with a flight control mechanism in a moored aircraft to form a moored following aircraft, and the ground measuring unit is connected with a moored ground power supply in a moored system to form a moored ground station. And the mooring aircraft is connected with the mooring ground power supply through a mooring cable. The device is easy to deploy, low in cost and capable of being suitable for most environments and used for a long time, movement following of the mooring aircraft to a mooring ground station is completed, meanwhile, the invention further discloses a control method of the movement following device of the mooring aircraft, and the method is good in practicability, easy to operate and capable of keeping a good following effect in rapid movement.

Description

Technical Field

[0001] The invention relates to a tethered unmanned aerial vehicle technology, in particular to a tethered aircraft mobile following device and a control method. Background Art

[0002] In the disclosed prior art, features such as tethered cables, high-precision positioning and inertial navigation are used to achieve the tethered aircraft following function.

[0003] Regarding the use of the tethered cable feature to achieve tethered aircraft following, according to the Chinese patent publication number CN201610152513, a cross-axis with a gyroscope sensor is installed on the tethered aircraft, and the cross-axis is connected to the tethered ground station through the tethered cable. When the tethered ground station starts to move relative to the tethered aircraft, the tethered cable pulls the cross-axis and causes its angle to change. After the gyroscope sensor on the cross-axis detects the change, the tethered aircraft adjusts its flight state accordingly to achieve the following effect. This technical solution has a large defect in an actual use environment with a certain wind speed. For example, when the tethered aircraft hovers at an altitude of tens of meters, the tethered ground station does not move relative to the tethered aircraft. At this time, a certain wind speed can bend the tethered cable and generate a certain pulling force on the cross-axis, so that the gyroscope sensor on the cross-axis detects the angle change, causing the tethered aircraft to execute wrong flight instructions, making it difficult to achieve the expected following or hovering effect; Regarding high-precision positioning to achieve tethered aircraft following, according to the Chinese patent publication number CN202411198902, RTK high-precision positioning units are installed on the tethered aircraft and the tethered ground station. Through the high-precision three-dimensional positioning information of the two, the flight state of the tethered aircraft is adjusted to enable it to complete the following action of the tethered ground station. This technical solution first requires the construction of a mobile station and a base station for RTK positioning. An additional data transmission channel is also required between the two stations for RTK to perform positioning data fusion, which greatly increases the cost of the entire system, increases the difficulty of maintenance, and complicates deployment; secondly, RTK is highly dependent on the signal coverage and quality of positioning satellites. In actual conditions such as thick clouds, thunderstorms, and complex electromagnetic environments, it often fails to achieve the expected effect. Finally, due to the update frequency of positioning satellite data, it is difficult for a tethered aircraft to follow the tethered platform when it moves rapidly. In addition, there is also a tethered aircraft following system that uses a camera for visual high-precision positioning. This technical solution is very dependent on the use environment. Factors such as ambient light, meteorological conditions, and location distance will have a great impact on the following effect, and the applicable scenarios are very limited; Regarding the use of inertial navigation technology to achieve tethered aircraft following, according to the Chinese patent publication number CN202410310341, nine-axis attitude sensors are installed on the tethered aircraft and the tethered ground station respectively, and the inertial navigation technology is used to calculate the relative motion state of the tethered aircraft and the tethered ground station, and then adjust the flight attitude of the tethered aircraft to enable it to complete the following action of the tethered ground station. Due to the existence of integral errors and sensor errors in the calculation process, the estimation error of the motion state of this technical solution will continue to accumulate as time goes by in the use scenarios of several hours or dozens of hours, and ultimately the relative motion state of the tethered aircraft and the tethered ground station cannot be calculated normally, and it is difficult to ensure the effect of long-term hovering or following.

[0004] To sum up, in the currently disclosed existing technologies, the actual use environment conditions have a great influence on the implementation effect of the tethered following system. In addition, most of the above technical solutions emphasize the following implementation effect of the tethered aircraft and the tethered ground station in the horizontal plane, and almost do not involve the following implementation in the vertical direction. Summary of the invention

[0005] The purpose of the present invention is to provide a tethered aircraft mobile following device and control method to address the deficiencies of the prior art. The device is simple to deploy, low in cost, can be used in most environments and for a long time, and can complete the mobile following of the tethered aircraft to the tethered ground station. The method is practical, simple to operate, and can maintain a good following effect during rapid movement.

[0006] The technical solution for achieving the purpose of the present invention is: A tethered aircraft mobile following device comprises an aircraft measuring unit and a ground measuring unit. The aircraft measuring unit is connected to a flight control mechanism in a tethered aircraft to form a tethered following aircraft. The ground measuring unit is connected to a tethered ground power supply in a tethered system to form a tethered ground station. The tethered aircraft and the tethered ground power supply are connected via a tethered cable. The tethered aircraft mobile following device adopts angle of arrival AOA (Angle-of-Arriva, referred to as AoA) ranging positioning and high-speed communication technology with strong anti-interference ability and centimeter-level accuracy in ultra-wideband UWB (Ultra-WideBand, referred to as UWB) communication to achieve tethered aircraft mobile following. The aircraft measuring unit is used to measure the air pressure value and the direction of the aircraft. At the same time, the distance and direction angle from the tethered ground station to the tethered following aircraft are measured and acquired through the UWB AoA technology. The ground measuring unit is used to measure the air pressure value and the direction of the tethered ground station, send the measurement data to the aircraft measuring unit via UWB, and respond to the UWB ranging and direction data.

[0007] The aircraft measurement unit includes a first microcontroller unit and a first magnetometer unit, a first barometer unit and a UWB AoA communication unit connected to the first microcontroller unit, and is deployed and installed on the tethered following aircraft. The first microcontroller unit is connected to the flight control mechanism of the tethered following aircraft through a data interface, and can perform attitude control on the tethered following aircraft; the first magnetometer unit is used to measure the orientation of the tethered following aircraft; the first barometer unit is used to measure the air pressure value of the tethered following aircraft; the UWB AoA communication unit obtains the measurement data sent by the ground measurement unit, and at the same time performs AoA ranging and direction measurement on the ground station where the ground measurement unit is located. The aircraft measurement unit calculates the next action data of the tethered following aircraft based on the received data and local measurement data, and sends it to the flight control mechanism for execution.

[0008] The ground measurement unit includes a second microcontroller unit and a second magnetometer unit, a second barometer unit and a UWB communication unit connected to the second microcontroller unit, and is deployed and installed on a tethered ground station. The second magnetometer unit is used to measure the orientation of the tethered ground station, and the second barometer unit is used to measure the air pressure value of the tethered ground station. The UWB communication unit sends the measurement data to the aircraft measurement unit and also responds to the UWB AoA ranging and direction data.

[0009] The meteorological conditions, electromagnetic conditions, and implementation time of the actual use environment may have a significant impact on the implementation effect of the tethered following system. The technical principle of the mobile following device of the tethered aircraft in this technical solution to implement the following function is based on the alignment and coincidence of the coordinate systems of the tethered following aircraft and the tethered ground station. The yaw axis, pitch axis, and roll axis of the tethered following aircraft constitute the attitude coordinate system of the tethered following aircraft, which completely coincides with the spatial position coordinate system of the tethered following aircraft. The horizontal x-axis, horizontal y-axis, and vertical z-axis of the tethered ground station constitute the spatial position coordinate system of the tethered ground station, which also serves as the spatial position coordinate system of the entire tethered following system. The tethered following function is to ensure the alignment of the coordinate systems of the two within the specified vertical height range. Alignment and coincidence: before the mobile following device of the tethered aircraft starts working, ensure that the tethered following aircraft and the tethered ground station are at the same origin and in the same direction, that is, the two coordinate systems basically coincide; after the mobile following device of the tethered aircraft starts working, the tethered following aircraft tilts and rotates around the pitch axis, which can make the tethered aircraft move on the horizontal x-axis of the spatial position coordinate system; tilts and rotates around the roll axis, which can make the tethered aircraft move on the horizontal y-axis of the spatial position coordinate system; tilts and rotates around the yaw axis to adjust the direction of the nose, thereby completing the following function of the tethered following aircraft and the tethered ground station.

[0010] A control method for a tethered aircraft movement following device, using the tethered aircraft movement following device, the method comprises the following steps: 1) The aircraft measurement unit is connected to the flight control mechanism of the tethered aircraft to control the movements of the tethered following aircraft, and at the same time obtains the measurement data and ranging and direction finding data of the ground measurement unit through UWB; 2) According to the difference in air pressure between the aircraft measurement unit and the ground measurement unit, the aircraft measurement unit calculates the relative height between the tethered following aircraft and the tethered ground station, and then obtains the vertical adjustment range, controls the flight control mechanism to make vertical adjustments, and completes the vertical z-axis following; 3) According to the difference in the geomagnetic pointing angles between the aircraft measurement unit and the ground measurement unit, the aircraft measurement unit calculates the relative orientation of the tethered following aircraft and the tethered ground station, and then obtains the adjustment amplitude in the yaw direction, controls the flight control to adjust the yaw axis direction, and completes the orientation following of the tethered following aircraft and the tethered ground station, that is, ensures that the roll axis of the tethered following aircraft coincides with or is parallel to the horizontal x-axis of the tethered ground station.

[0011] 4) Based on the changes in the UWB AoA angle and straight-line distance of the aircraft measurement unit and the ground measurement unit, the aircraft measurement unit calculates the horizontal adjustment range required for the tethered following aircraft, controls the flight control to adjust the pitch axis, and completes the horizontal x-axis following; 5) Combining the data from step 1) to step 4), based on the straight-line distance between the tethered following aircraft and the tethered ground station, the aircraft measurement unit controls the flight control to fine-tune the tethered following aircraft to complete the horizontal y-axis following.

[0012] The advantages or beneficial effects of this technical solution are as follows: 1. The relative height is calculated by using the pressure difference between the tethered ground station and the tethered following aircraft. The height of the tethered following aircraft is adjusted according to the relative height to complete the vertical following function. 2. Fast air pressure, geomagnetic, distance data measurement and UWB transmission speed, able to maintain good tracking effect during fast movement; 3. No external satellite data or additional mechanical structure is required, and it does not rely on external conditions such as weather, light, and geomagnetism in the implementation environment. It can adapt to most implementation scenarios, with low deployment cost and high reliability. 4. All measurement data are collected in real time and compensated by difference, without complicated mathematical operations, to avoid long-term integration errors and ensure long-term following effects.

[0013] This device is easy to deploy, low-cost, suitable for most environments and can be used for a long time. It can complete the mobile following of the tethered aircraft to the tethered ground station. This method is practical, easy to operate, and can maintain a good following effect during fast movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of a mobile following device for a tethered aircraft according to an embodiment; Figure 2 is a schematic diagram of the structure of an aircraft measurement unit in an embodiment; Figure 3 is a schematic diagram of the structure of a ground measurement unit in an embodiment; Figure 4 It is a schematic diagram of the mobile following technology principle of the tethered following aircraft in the embodiment; Figure 5 It is a schematic diagram of the pitch axis following of the tethered following aircraft in the embodiment; Figure 6 A schematic diagram of the yaw axis following of a tethered following aircraft in an embodiment; Figure 7 It is a schematic diagram of the roll axis following of the tethered following aircraft in the embodiment. DETAILED DESCRIPTION

[0015] The content of the present invention is further described below in conjunction with the drawings and embodiments, but the present invention is not limited thereto.

[0016] Example:

[0017] Reference Figure 1 A tethered aircraft mobile following device comprises an aircraft measuring unit and a ground measuring unit. The aircraft measuring unit is connected to a flight control mechanism in the tethered aircraft to form a tethered following aircraft. The ground measuring unit is connected to a tethered ground power supply in a tethered system to form a tethered ground station. The tethered aircraft and the tethered ground power supply are connected through a tethered cable. The tethered aircraft mobile following device adopts AOA ranging positioning and high-speed communication technology with strong anti-interference ability and centimeter-level accuracy in ultra-wideband UWB communication to realize the mobile following of the tethered aircraft. The aircraft measuring unit is used to measure the air pressure value and the direction of the aircraft. At the same time, the UWB AoA technology is used to measure and obtain the distance and direction angle from the tethered ground station to the tethered following aircraft. The ground measuring unit is used to measure the air pressure value and the direction of the tethered ground station, and send the measurement data to the aircraft measuring unit through UWB, and respond to the UWB ranging and direction data at the same time.

[0018] like Figure 2As shown, the aircraft measurement unit includes a first microcontroller unit and a first magnetometer unit, a first barometer unit and a UWB AoA communication unit connected to the first microcontroller unit, and is deployed and installed on the tethered following aircraft. The first microcontroller unit is connected to the flight control mechanism of the tethered following aircraft through a data interface, and can perform attitude control on the tethered following aircraft; the first magnetometer unit is used to measure the geomagnetic pointing angle of the tethered following aircraft; the first barometer unit is used to measure the air pressure value of the tethered following aircraft; the UWB AoA communication unit obtains the measurement data sent by the ground measurement unit, and at the same time performs AoA ranging and direction measurement on the tethered ground station where the ground measurement unit is located. The aircraft measurement unit calculates the next action data of the tethered following aircraft based on the received data and local measurement data, and sends it to the flight control mechanism for execution.

[0019] like Figure 3 As shown, the ground measurement unit includes a second microcontroller unit and a second magnetometer unit, a second barometer unit and a UWB communication unit connected to the second microcontroller unit, and is deployed and installed on a tethered ground station. The second magnetometer unit is used to measure the geomagnetic pointing angle of the tethered ground station, and the second barometer unit is used to measure the air pressure value of the tethered ground station. The UWB communication unit sends the measurement data to the aircraft measurement unit and also responds to the UWB AoA ranging and direction finding data.

[0020] like Figure 4 As shown, the meteorological conditions, electromagnetic conditions, and implementation time of the actual use environment may have a significant impact on the implementation effect of the tethered following system. The technical principle of the mobile following device of the tethered aircraft in this technical solution to implement the following function is based on the alignment and coincidence of the coordinate systems of the tethered following aircraft and the tethered ground station. The yaw axis, pitch axis, and roll axis of the tethered following aircraft constitute the attitude coordinate system of the tethered following aircraft, which completely coincides with the spatial position coordinate system of the tethered following aircraft. The horizontal x-axis, horizontal y-axis, and vertical z-axis of the tethered ground station constitute the spatial position coordinate system of the tethered ground station, which also serves as the spatial position coordinate system of the entire tethered following system. The tethered following function is to ensure the alignment of the coordinate systems of the two within the specified vertical height range. Alignment and coincidence: before the mobile following device of the tethered aircraft starts working, ensure that the tethered following aircraft and the tethered ground station are at the same origin and in the same direction, that is, the two coordinate systems basically coincide; after the mobile following device of the tethered aircraft starts working, the tethered following aircraft tilts and rotates around the pitch axis, which can make the tethered aircraft move on the horizontal x-axis of the spatial position coordinate system; tilts and rotates around the roll axis, which can make the tethered aircraft move on the horizontal y-axis of the spatial position coordinate system; tilts and rotates around the yaw axis to adjust the direction of the nose, thereby completing the following function of the tethered following aircraft and the tethered ground station.

[0021] A control method for a tethered aircraft movement following device, using the tethered aircraft movement following device, the method comprises the following steps: 1) The aircraft measurement unit is connected to the flight control mechanism of the tethered aircraft to control the movements of the tethered following aircraft, and at the same time obtains the measurement data and ranging and direction finding data of the ground measurement unit through UWB; 2) According to the difference in air pressure between the aircraft measurement unit and the ground measurement unit, the aircraft measurement unit calculates the relative height between the tethered following aircraft and the tethered ground station, and then obtains the vertical adjustment range, controls the flight control mechanism to make vertical adjustments, and completes the vertical z-axis following; 3) According to the difference in the geomagnetic pointing angles between the aircraft measurement unit and the ground measurement unit, the aircraft measurement unit calculates the relative orientation of the tethered following aircraft and the tethered ground station, and then obtains the adjustment amplitude in the yaw direction, controls the flight control to adjust the yaw axis direction, and completes the orientation following of the tethered following aircraft and the tethered ground station, that is, ensures that the roll axis of the tethered following aircraft coincides with or is parallel to the horizontal x-axis of the tethered ground station; 4) Based on the changes in the UWB AoA angle and straight-line distance of the aircraft measurement unit and the ground measurement unit, the aircraft measurement unit calculates the horizontal adjustment range required for the tethered following aircraft, controls the flight control to adjust the pitch axis, and completes the horizontal x-axis following; 5) Combining the data from step 1) to step 4), based on the straight-line distance between the tethered following aircraft and the tethered ground station, the aircraft measurement unit controls the flight control to fine-tune the tethered following aircraft to complete the horizontal y-axis following.

[0022] In this example, specifically: In this example, the tethered follower aircraft is called S 1 , the tethered ground station is S 2 , the aircraft measurement unit is M 1 , the ground measurement unit is M 2 , S 1 The air pressure value and geomagnetic direction angle are P 1 and D 1 , S 2 The air pressure value and geomagnetic direction angle are P 2 and D 2 , S 1 With S 2 The straight-line distance and direction angle are L and α, S 1 With S 2 After the relative height is determined, the pressure difference is B and the relative height is H; a. Initialization phase: ① Adjust S1 Nose direction and S 2 Same direction, S 2 The orientation can be determined by the installation method of the second magnetometer unit, namely D 2 To determine, and S 1 With S 2 At the same origin, so as to ensure that the spatial position coordinate systems of the two are basically coincident; ②S 1 and S 2 Power on, M 1 Measuring P 1 , D 1 , M 2 Measuring P 2 , D 2 , and establish a UWB communication connection between the two, M 1 Get P 2 and D 2 Value, according to P 1 and D 1 , perform data difference normalization processing to obtain △P and △D, at which time △P and △D approach 0; ③S 1 Ascend to the specified height, M 1 Start UWB AoA direction finding and ranging, obtain L and α, and record the values ​​of B and H; b. Follow-up implementation phase: ①M 1 Get P in real time 1 and P 2 value, and calculate △P, and follow the vertical z-axis direction. If P 2 Decrease, indicating S 2 Moving along the negative direction of the vertical z axis, M 1 Send a command to the flight controller to set S 1 Make vertical downward movement adjustment until △P approaches B; if P 2 Increase, explain S 2 Moving along the positive direction of the vertical z axis, M 1 Send a command to the flight controller to set S 1 Perform vertical upward movement adjustment until △P approaches B; ②M 1 Get the α value in real time and follow the horizontal x-axis direction. The principle is as follows Figure 5 As shown, if α is in the fourth quadrant of the coordinate plane formed by the horizontal x-axis and the vertical z-axis, it means that S 1 Behind S 2 , M 1 Send a command to the flight controller to set S 1 Adjust the pitch axis angle so that S 1Move along the positive direction of the horizontal x-axis until α approaches 0; if α is in the third quadrant of the coordinate plane formed by the horizontal x-axis and the vertical z-axis, it means that S 1 Ahead of S 2 , M 1 Send a command to the flight controller to set S 1 Adjust the pitch axis angle so that S 1 Move along the negative direction of the horizontal x-axis until α approaches 0; ③M 1 Get D in real time 1 and D 2 value, and calculate △D, and perform S 1 For S 2 Following the direction of movement, such as Figure 6 As shown, if △D is in the first quadrant of the coordinate plane formed by the horizontal x-axis and the horizontal y-axis, it means that S 2 The pointing angle is rotating to the right, M 1 Send a command to the flight controller to set S 1 Adjust the yaw axis angle so that S 1 The pointing angle rotates to the right until △D approaches 0; if △D is in the second quadrant of the coordinate plane formed by the horizontal x-axis and the horizontal y-axis, it means that S 2 The pointing angle is rotating to the left, M 1 Send a command to the flight controller to set S 1 Adjust the yaw axis angle so that S 1 The pointing angle rotates to the left until △D approaches 0; ④ M 1 Get the L value in real time and follow the horizontal y-axis direction. The principle is as follows Figure 7 As shown, according to steps ② and ③, S can be estimated 1 At the approximate position of the coordinate plane formed by the horizontal y-axis and the vertical z-axis, M 1 Send a command to the flight controller to set S 1 Adjust the roll axis angle so that S 1 Move along the horizontal y-axis until L approaches H; In the continuous motion state, repeat the above steps to complete S 1 For S 2 The following effect.

Claims

1. A tethered aircraft mobile following device, characterized in that: It includes an aircraft measurement unit and a ground measurement unit. The aircraft measurement unit is connected to the flight control mechanism in the tethered aircraft to form a tethered following aircraft. The ground measurement unit is connected to the tethered ground power supply in the tethered system to form a tethered ground station. The tethered aircraft and the tethered ground power supply are connected through a tethered cable.

2. The tethered aircraft movement following device according to claim 1, characterized in that: The aircraft measurement unit includes a first microcontroller unit and a first magnetometer unit, a first barometer unit and a UWB AoA (Ultra-WideBand, Angle-of-Arrival, referred to as UWB AoA) communication unit connected to the first microcontroller unit, and is deployed and installed on a tethered following aircraft. The first microcontroller unit is connected to the flight control mechanism of the tethered aircraft through a data interface.

3. The tethered aircraft movement following device according to claim 1, characterized in that: The ground measurement unit includes a second microcontroller unit and a second magnetometer unit connected to the second microcontroller unit, a second barometer unit and a UWB communication unit, and is deployed and installed on a tethered ground station.

4. A control method for a tethered aircraft movement following device, using the tethered aircraft movement following device according to claim 1 to claim 3, characterized in that: The method comprises the following steps: 1) The aircraft measurement unit is connected to the flight control mechanism of the tethered aircraft to control the movements of the tethered following aircraft, and at the same time obtains the measurement data and ranging and direction finding data of the ground measurement unit through UWB; 2) According to the difference in air pressure between the aircraft measurement unit and the ground measurement unit, the aircraft measurement unit calculates the relative height between the tethered following aircraft and the tethered ground station, and then obtains the vertical adjustment range, controls the flight control mechanism to make vertical adjustments, and completes the vertical z-axis following; 3) According to the difference in the geomagnetic pointing angles between the aircraft measurement unit and the ground measurement unit, the aircraft measurement unit calculates the relative orientation of the tethered following aircraft and the tethered ground station, and then obtains the adjustment amplitude in the yaw direction, controls the flight control to adjust the yaw axis direction, and completes the orientation following of the tethered following aircraft and the tethered ground station, that is, ensures that the roll axis of the tethered following aircraft coincides with or is parallel to the horizontal x-axis of the tethered ground station; 4) Based on the changes in the UWB AoA angle and straight-line distance of the aircraft measurement unit and the ground measurement unit, the aircraft measurement unit calculates the horizontal adjustment range required for the tethered following aircraft, controls the flight control to adjust the pitch axis, and completes the horizontal x-axis following; 5) Combining the data from step 1) to step 4), based on the straight-line distance between the tethered following aircraft and the tethered ground station, the aircraft measurement unit controls the flight control to fine-tune the tethered following aircraft to complete the horizontal y-axis following.

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