A fixed-wing unmanned aerial vehicle timing arrival target position control method

Abstract

The application discloses a fixed-wing unmanned aerial vehicle timing arrival target position control method. The method can comprise the following steps: determining the time consumption / time point and destination coordinates, and then performing the fastest height control on the unmanned aerial vehicle; calculating the target indicated airspeed and weighted target indicated airspeed of each flight section; and performing real-time control on the unmanned aerial vehicle based on the target indicated airspeed, the weighted target indicated airspeed and a safety adjustment range. The safety adjustment range of the unmanned aerial vehicle is utilized to achieve the purpose of timing arrival at the target position.

Description

Technical Field

[0001] This invention relates to the field of fixed-wing unmanned aerial vehicle (UAV) design and research, and more specifically, to a method for controlling a fixed-wing UAV to arrive at a target location at a set time. Background Technology

[0002] With the rapid development of the drone industry, the expanding application scenarios of drones are driving their continuous progress in terms of intelligence and autonomy. Currently, the ability of drones to deliver supplies over long distances and to reach targets on time during coordinated military strikes mainly relies on pre-mission flight path planning and real-time intervention by drone operators. The final result is heavily influenced by environmental factors and the experience of the operators, leading to unstable mission outcomes.

[0003] Currently, much research focuses on path planning methods that can be dynamically adjusted in real time. However, such methods suffer from flight path uncertainty, increasing the burden on commanders during mission execution and placing excessive demands on air traffic control systems in multi-aircraft scenarios. The application of fixed-wing UAVs in specific scenarios necessitates the ability to fully utilize the UAV's safe adjustment range, wait within designated areas, and provide early warnings when arrival is anticipated.

[0004] Therefore, it is necessary to develop a method for controlling fixed-wing UAVs to arrive at target locations on a timed basis.

[0005] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] This invention proposes a method for controlling a fixed-wing unmanned aerial vehicle (UAV) to arrive at a target location at a specific time, comprising: Determine the arrival time / moment and destination coordinates, and then control the drone to the fastest altitude. Calculate the target indicated airspeed and weighted target indicated airspeed for each flight segment; Real-time control of the UAV is achieved based on the target indicated airspeed, weighted target indicated airspeed, and safe adjustment range.

[0007] Preferably, the maximum speed height control includes: If the current altitude is 20m higher than the destination altitude, then descend to the destination altitude at the maximum indicated airspeed. If the current altitude is 20m lower than the destination altitude, then climb to the destination altitude using the maximum trajectory climb angle.

[0008] Preferably, the target indicated airspeed is:

[0009] in, The total length of all existing flight segments from the origin to the destination. For the total arrival time, For wind speed, For the deflection angle, Atmospheric density at the destination This refers to standard atmospheric density.

[0010] Preferably, the weighted target indicated airspeed is:

[0011] in, The total length of all existing flight segments from the origin to the destination. For the length of each flight segment, The target airspeed is indicated for each flight segment.

[0012] Preferably, real-time control of the UAV based on the target indicated airspeed, the weighted target indicated airspeed, and the safe adjustment range includes: a. Determine whether the target airspeed for each flight segment is within the safe adjustment range without using flaps. If yes, perform normal arrival control; otherwise, proceed to step b. b. Determine whether the target airspeed for each flight segment is within the safe adjustment range for using flaps. If yes, perform normal flap arrival control; otherwise, proceed to step c. c. Determine whether the weighted target airspeed is within the safe adjustment range without using flaps. If yes, calculate the compensated target airspeed and perform advanced arrival control. If no, proceed to step d. d. Determine whether the weighted target airspeed is within the safe adjustment range for using flaps. If yes, calculate the compensated target airspeed and perform advanced flap arrival control. If no, proceed to step e. e. Determine whether the weighted target indicated airspeed is greater than the upper limit of the safe adjustment range. If yes, issue an alarm. If no, automatically fly to a position 2km away from the destination, hover, and proceed to step f. f. Determine if the weighted target airspeed is within the safe adjustment range. If yes, fly to the destination; otherwise, continue circling.

[0013] Preferably, general arrival control includes: Set the drone's longitude command value to the longitude of the current flight segment's endpoint; Set the drone's latitude command value to the latitude of the current flight segment's endpoint; Set the drone's altitude command value to the altitude of the current flight segment's endpoint; Set the UAV's indicated airspeed command value to the target indicated airspeed for the current flight segment.

[0014] Preferably, conventional flap arrival control includes: Set the drone's longitude command value to the longitude of the current flight segment's endpoint; Set the drone's latitude command value to the latitude of the current flight segment's endpoint; Set the drone's altitude command value to the altitude of the current flight segment's endpoint; Set the drone flap command value to the target flap value within the safe adjustment range; Set the UAV's indicated airspeed command value to the target indicated airspeed for the current flight segment.

[0015] Preferably, the compensated target airspeed is:

[0016] in, Indicate the target airspeed for each flight segment. This represents the remaining length of the current flight segment. For the length of each flight segment, For wind speed, For the deflection angle, Atmospheric density at the destination This is the standard atmospheric density.

[0017] Preferably, advanced arrival control includes: Set the drone's longitude command value to the longitude of the current flight segment's endpoint; Set the drone's latitude command value to the latitude of the current flight segment's endpoint; Set the drone's altitude command value to the altitude of the current flight segment's endpoint; Set the drone's indicated airspeed command value to compensate for the target airspeed.

[0018] Preferably, advanced flap arrival control includes: Set the drone's longitude command value to the longitude of the current flight segment's endpoint; Set the drone's latitude command value to the latitude of the current flight segment's endpoint; Set the drone's altitude command value to the altitude of the current flight segment's endpoint; Set the drone flap command value to the target flap value within the safe adjustment range; Set the drone's indicated airspeed command value to compensate for the target airspeed.

[0019] The method of the present invention has other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0020] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same parts.

[0021] Figure 1 A flowchart illustrating the steps of a fixed-wing unmanned aerial vehicle (UAV) timing arrival control method according to an embodiment of the present invention is shown.

[0022] Figure 2 The software interface for a fixed-wing unmanned aerial vehicle (UAV) to arrive at a target location on a timed basis, according to an embodiment of the present invention, is shown.

[0023] Figure 3 A structural diagram of a maximum altitude control system for a fixed-wing unmanned aerial vehicle based on a safety adjustment range, according to an embodiment of the present invention, is shown.

[0024] Figure 4 A diagram illustrating the safety adjustment range of a fixed-wing unmanned aerial vehicle according to an embodiment of the present invention is shown.

[0025] Figure 5 A structural diagram of a fixed-wing unmanned aerial vehicle (UAV) timed arrival control system based on a safety adjustment range according to an embodiment of the present invention is shown.

[0026] Figure 6 An embodiment of the present invention is shown. Bode plot of open-loop transfer function.

[0027] Figure 7 An embodiment of the present invention is shown. Bode plot of closed-loop transfer function.

[0028] Figure 8 A cruise phase indication airspeed step response diagram is shown according to an embodiment of the present invention.

[0029] Figure 9 An alarm diagram is shown when a fixed-wing UAV fails to reach the target location on time, according to an embodiment of the present invention.

[0030] Figure 10The diagram shows a comparison of actual flight conditions of a fixed-wing UAV timing arrival control method according to an embodiment of the present invention. Detailed Implementation

[0031] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0032] To facilitate understanding of the solutions and effects of the embodiments of the present invention, a specific application example is given below. Those skilled in the art should understand that this example is merely for the purpose of understanding the present invention, and any specific details therein are not intended to limit the present invention in any way.

[0033] Example 1

[0034] Figure 1 A flowchart illustrating the steps of a fixed-wing unmanned aerial vehicle (UAV) timing arrival control method according to an embodiment of the present invention is shown.

[0035] like Figure 1 As shown, the control method for the fixed-wing UAV to reach the target position at a time includes: Step 101: Determine the arrival time / moment and destination coordinates, and then control the drone to the fastest altitude. Step 102: Calculate the target indicated airspeed and weighted target indicated airspeed for each flight segment; Step 103: Real-time control of the UAV is performed based on the target indicated airspeed, the weighted target indicated airspeed, and the safe adjustment range.

[0036] In one example, the maximum speed height control includes: If the current altitude is 20m higher than the destination altitude, then descend to the destination altitude at the maximum indicated airspeed. If the current altitude is 20m lower than the destination altitude, then climb to the destination altitude using the maximum trajectory climb angle.

[0037] In one example, the target indicated airspeed is:

[0038] in, The total length of all existing flight segments from the origin to the destination. For the total arrival time, For wind speed, For the deflection angle, Atmospheric density at the destination This is the standard atmospheric density.

[0039] In one example, the weighted target indicated airspeed is:

[0040] in, The total length of all existing flight segments from the origin to the destination. For the length of each flight segment, The target airspeed is indicated for each flight segment.

[0041] In one example, real-time control of a drone based on target indicated airspeed, weighted target indicated airspeed, and a safe adjustment range includes: a. Determine whether the target airspeed for each flight segment is within the safe adjustment range without using flaps. If yes, perform normal arrival control; otherwise, proceed to step b. b. Determine whether the target airspeed for each flight segment is within the safe adjustment range for using flaps. If yes, perform normal flap arrival control; otherwise, proceed to step c. c. Determine whether the weighted target airspeed is within the safe adjustment range without using flaps. If yes, calculate the compensated target airspeed and perform advanced arrival control. If no, proceed to step d. d. Determine whether the weighted target airspeed is within the safe adjustment range for using flaps. If yes, calculate the compensated target airspeed and perform advanced flap arrival control. If no, proceed to step e. e. Determine whether the weighted target indicated airspeed is greater than the upper limit of the safe adjustment range. If yes, issue an alarm. If no, automatically fly to a position 2km away from the destination, hover, and proceed to step f. f. Determine if the weighted target airspeed is within the safe adjustment range. If yes, fly to the destination; otherwise, continue circling.

[0042] In one example, standard arrival control includes: Set the drone's longitude command value to the longitude of the current flight segment's endpoint; Set the drone's latitude command value to the latitude of the current flight segment's endpoint; Set the drone's altitude command value to the altitude of the current flight segment's endpoint; Set the UAV's indicated airspeed command value to the target indicated airspeed for the current flight segment.

[0043] In one example, conventional flap arrival control includes: Set the drone's longitude command value to the longitude of the current flight segment's endpoint; Set the drone's latitude command value to the latitude of the current flight segment's endpoint; Set the drone's altitude command value to the altitude of the current flight segment's endpoint; Set the drone flap command value to the target flap value within the safe adjustment range; Set the UAV's indicated airspeed command value to the target indicated airspeed for the current flight segment.

[0044] In one example, the target airspeed to be compensated is:

[0045] in, Indicate the target airspeed for each flight segment. This represents the remaining length of the current flight segment. For the length of each flight segment, For wind speed, For the deflection angle, Atmospheric density at the destination This refers to standard atmospheric density.

[0046] In one example, advanced arrival control includes: Set the drone's longitude command value to the longitude of the current flight segment's endpoint; Set the drone's latitude command value to the latitude of the current flight segment's endpoint; Set the drone's altitude command value to the altitude of the current flight segment's endpoint; Set the drone's indicated airspeed command value to compensate for the target airspeed.

[0047] In one example, advanced flap arrival control includes: Set the drone's longitude command value to the longitude of the current flight segment's endpoint; Set the drone's latitude command value to the latitude of the current flight segment's endpoint; Set the drone's altitude command value to the altitude of the current flight segment's endpoint; Set the drone flap command value to the target flap value within the safe adjustment range; Set the drone's indicated airspeed command value to compensate for the target airspeed.

[0048] Figure 2 The software interface for a fixed-wing unmanned aerial vehicle (UAV) to arrive at a target location on a timed basis, according to an embodiment of the present invention, is shown.

[0049] Specifically, such as Figure 2 As shown, the arrival time / moment and destination coordinates are input and uploaded through the ground operation software. The destination coordinates include the longitude, latitude, and altitude of the destination.

[0050] Figure 3 A structural diagram of a maximum altitude control system for a fixed-wing unmanned aerial vehicle based on a safety adjustment range, according to an embodiment of the present invention, is shown.

[0051] like Figure 3 As shown, the drone is controlled to reach its maximum altitude. If the current altitude is 20m higher than the destination altitude, the drone will descend to the destination altitude at the maximum indicated airspeed. If the current altitude is 20m lower than the destination altitude, the drone will climb to the destination altitude at the maximum trajectory climb angle.

[0052] The target indicated airspeed for each flight segment is calculated as follows: (1) in, The total length of all existing flight segments from the origin to the destination. For the total arrival time, For wind speed, For the deflection angle, Atmospheric density at the destination This is the standard atmospheric density.

[0053] The weighted target indicated airspeed is calculated as follows: (2) in, For the length of each flight segment, Indicate the target airspeed for each flight segment. This represents the total length of all existing flight segments from the origin to the destination.

[0054] Real-time control of the UAV is achieved based on the target indicated airspeed, weighted target indicated airspeed, and the safe adjustment range. The safe adjustment range refers to the envelope of the indicated airspeed adjustment range, which is the boundary between the minimum indicated airspeed value that ensures safe flight at different altitudes and the maximum indicated airspeed value determined by engine thrust.

[0055] Figure 4 A diagram illustrating the safety adjustment range of a fixed-wing unmanned aerial vehicle according to an embodiment of the present invention is shown.

[0056] like Figure 4 As shown, the addition of flaps can provide a smaller safety adjustment limit for fixed-wing UAVs, which is beneficial for realizing the timed arrival function.

[0057] Figure 5 A structural diagram of a fixed-wing unmanned aerial vehicle (UAV) timed arrival control system based on a safety adjustment range according to an embodiment of the present invention is shown.

[0058] like Figure 5 As shown, based on the target indicated airspeed, weighted target indicated airspeed, and safe adjustment range, real-time control of the UAV includes: a. Determine whether the target indicated airspeed for each flight segment is within the safe adjustment range without using flaps. If yes, proceed with normal arrival control; otherwise, proceed to step b. The normal arrival control process includes: setting the UAV longitude command value to the longitude of the current flight segment's endpoint; setting the UAV latitude command value to the latitude of the current flight segment's endpoint; setting the UAV altitude command value to the altitude of the current flight segment's endpoint; and setting the UAV indicated airspeed command value to the target indicated airspeed for the current flight segment. b. Determine if the target indicated airspeed for each flight segment is within the safe adjustment range for using flaps. If yes, perform normal flap arrival control; otherwise, proceed to step c. The normal flap arrival control process includes: setting the UAV longitude command value to the longitude of the current flight segment's endpoint; setting the UAV latitude command value to the latitude of the current flight segment's endpoint; setting the UAV altitude command value to the altitude of the current flight segment's endpoint; setting the UAV flap command value to the target flap value with sufficient safe adjustment range; and setting the UAV indicated airspeed command value to the target indicated airspeed for the current flight segment. c. Determine whether the weighted target indicated airspeed is within the safe adjustment range without using flaps. If yes, calculate the compensated target airspeed and perform advanced arrival control. If not, proceed to step d. The method for calculating the compensated target airspeed is as follows: (3) in, Indicate the target airspeed for each flight segment. This represents the remaining length of the current flight segment. For the length of each flight segment, For wind speed, For the deflection angle, Atmospheric density at the destination The standard atmospheric density is used. Advanced arrival control procedures include: setting the UAV's longitude command value to the longitude of the current flight segment's endpoint; setting the UAV's latitude command value to the latitude of the current flight segment's endpoint; setting the UAV's altitude command value to the altitude of the current flight segment's endpoint; and setting the UAV's indicated airspeed command value to the compensated target airspeed. d. Determine if the weighted target indicated airspeed is within the safe adjustment range for using flaps. If yes, calculate the compensated target airspeed and perform advanced flap arrival control. If not, proceed to step e. The advanced flap arrival control process includes: setting the UAV longitude command value to the longitude of the current flight segment's endpoint; setting the UAV latitude command value to the latitude of the current flight segment's endpoint; setting the UAV altitude command value to the altitude of the current flight segment's endpoint; setting the UAV flap command value to the target flap value with sufficient safe adjustment range; and setting the UAV indicated airspeed command value to the compensated target airspeed. e. Determine whether the weighted target indicated airspeed is greater than the upper limit of the safe adjustment range. If yes, issue an alarm. If no, automatically fly to a position 2km away from the destination and hover before proceeding to step f. The hovering methods include: re-entering the current flight segment; or performing circular flight with a fixed radius or roll angle centered at a position 2km away from the destination. f. Determine if the weighted target airspeed is within the safe adjustment range. If yes, fly to the destination; otherwise, continue circling.

[0059] To verify the effectiveness and feasibility of this invention, an analysis was first conducted from the perspectives of the time and frequency domains. Secondly, a MATLAB / Simulink simulation experiment was performed. Finally, the method involved was verified by actual flight testing. The specific results are as follows.

[0060] Figure 6 An embodiment of the present invention is shown. Bode plot of open-loop transfer function.

[0061] Figure 7 An embodiment of the present invention is shown. Bode plot of closed-loop transfer function.

[0062] from Figure 6 , Figure 7 As can be seen from the results, the stability analysis of the safety adjustment range controller is stable, with a phase margin of 87°.

[0063] Figure 8 A cruise phase indication airspeed step response diagram is shown according to an embodiment of the present invention.

[0064] like Figure 8 As shown, the indicated airspeed step response rise time during the cruise phase is 7.94s, peak time is 26.7s, settling time is 40.5s, and overshoot is 3.3%.

[0065] Figure 9 An alarm diagram is shown when a fixed-wing UAV fails to reach the target location on time, according to an embodiment of the present invention.

[0066] When the assessment indicates that the target location cannot be reached on time, an alarm will be triggered in the information prompt bar of the ground operation software to inform the operator that the timed arrival requirements need to be adjusted. This alarm will be triggered every 10 seconds and accompanied by a voice announcement. Figure 9 As shown.

[0067] Figure 10 The diagram shows a comparison of actual flight conditions of a fixed-wing UAV timing arrival control method according to an embodiment of the present invention.

[0068] from Figure 10As can be seen from the data, the fixed-wing UAV timed arrival at the target position control method can effectively reduce the impact of human and environmental factors on the timed arrival at the target position. The expanded adjustment range can maximize the control of the flight trajectory on the line connecting the two points. The actual flight results are shown in Table 1.

[0069] Table 1 Comparison of Timing Deviations of Different Methods

[0070] Simulation and flight verification fully demonstrate the feasibility and practicality of this method. The above results show that this method has the following advantages: 1) It makes full use of the safety adjustment range and avoids instability caused by human factors; 2) It makes full use of the available environmental information to introduce the control loop and reduces the uncertainty caused by environmental factors; 3) The lower automatic route adjustment authority facilitates the implementation of mission planning.

[0071] Those skilled in the art should understand that the above description of the embodiments of the present invention is only intended to illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any of the examples given.

[0072] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for controlling a fixed-wing unmanned aerial vehicle to arrive at a target location at a set time, characterized in that, include: Determine the arrival time / moment and destination coordinates, and then control the drone to the fastest altitude. Calculate the target indicated airspeed and weighted target indicated airspeed for each flight segment; Real-time control of the UAV is performed based on the target indicated airspeed, the weighted target indicated airspeed, and the safe adjustment range. Among these, real-time control of UAVs based on target indicated airspeed, weighted target indicated airspeed, and safe adjustment range includes: a. Determine whether the target airspeed for each flight segment is within the safe adjustment range without using flaps. If yes, perform normal arrival control; otherwise, proceed to step b. b. Determine whether the target airspeed for each flight segment is within the safe adjustment range for using flaps. If yes, perform normal flap arrival control; otherwise, proceed to step c. c. Determine whether the weighted target airspeed is within the safe adjustment range without using flaps. If yes, calculate the compensated target airspeed and perform advanced arrival control. If no, proceed to step d. d. Determine whether the weighted target airspeed is within the safe adjustment range for using flaps. If yes, calculate the compensated target airspeed and perform advanced flap arrival control. If no, proceed to step e. e. Determine whether the weighted target indicated airspeed is greater than the upper limit of the safe adjustment range. If yes, issue an alarm. If no, automatically fly to a position 2km away from the destination, hover, and proceed to step f. f. Determine if the weighted target airspeed is within the safe adjustment range. If yes, fly to the destination; otherwise, continue circling.

2. The method for controlling a fixed-wing unmanned aerial vehicle to arrive at a target position at a time according to claim 1, wherein, Maximum altitude control includes: If the current altitude is 20m higher than the destination altitude, then descend to the destination altitude at the maximum indicated airspeed. If the current altitude is 20m lower than the destination altitude, then climb to the destination altitude using the maximum trajectory climb angle.

3. The method for controlling a fixed-wing unmanned aerial vehicle to arrive at a target position at a time according to claim 1, wherein, The target indicated airspeed is: in, The total length of all existing flight segments from the origin to the destination. For the total arrival time, For wind speed, For the deflection angle, Atmospheric density at the destination This is the standard atmospheric density.

4. The method for controlling a fixed-wing unmanned aerial vehicle to arrive at a target position at a time according to claim 1, wherein, The weighted target indicated airspeed is: in, The total length of all existing flight segments from the origin to the destination. For the length of each flight segment, The target airspeed is indicated for each flight segment.

5. The method for controlling a fixed-wing unmanned aerial vehicle to arrive at a target position at a time according to claim 1, wherein, Standard arrival control includes: Set the drone's longitude command value to the longitude of the current flight segment's endpoint; Set the drone's latitude command value to the latitude of the current flight segment's endpoint; Set the drone's altitude command value to the altitude of the current flight segment's endpoint; Set the UAV's indicated airspeed command value to the target indicated airspeed for the current flight segment.

6. The method for controlling a fixed-wing unmanned aerial vehicle to arrive at a target position at a time according to claim 1, wherein, Conventional flap arrival control includes: Set the drone's longitude command value to the longitude of the current flight segment's endpoint; Set the drone's latitude command value to the latitude of the current flight segment's endpoint; Set the drone's altitude command value to the altitude of the current flight segment's endpoint; Set the drone flap command value to the target flap value within the safe adjustment range; Set the UAV's indicated airspeed command value to the target indicated airspeed for the current flight segment.

7. The method for controlling a fixed-wing unmanned aerial vehicle to arrive at a target position at a time according to claim 1, wherein, The target airspeed for compensation is: in, Indicate the target airspeed for each flight segment. This represents the remaining length of the current flight segment. For the length of each flight segment, For wind speed, For the deflection angle, Atmospheric density at the destination This is the standard atmospheric density.

8. The method for controlling a fixed-wing unmanned aerial vehicle to arrive at a target location at a time according to claim 7, wherein, Advanced arrival control includes: Set the drone's longitude command value to the longitude of the current flight segment's endpoint; Set the drone's latitude command value to the latitude of the current flight segment's endpoint; Set the drone's altitude command value to the altitude of the current flight segment's endpoint; Set the drone's indicated airspeed command value to compensate for the target airspeed.

9. The method for controlling a fixed-wing unmanned aerial vehicle to arrive at a target position at a time according to claim 7, wherein, Advanced flap arrival control includes: Set the drone's longitude command value to the longitude of the current flight segment's endpoint; Set the drone's latitude command value to the latitude of the current flight segment's endpoint; Set the drone's altitude command value to the altitude of the current flight segment's endpoint; Set the drone flap command value to the target flap value within the safe adjustment range; Set the drone's indicated airspeed command value to compensate for the target airspeed.

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