Target aircraft sustained high-g avoidance control method
By establishing an altitude control loop and an autopilot control system, and calculating smooth roll angle commands, the problem of altitude dispersion during high overload was solved, achieving stable altitude control and ensuring the success of the flight mission.
Patent Information
- Application Number
- CN202211355698.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-11-01
- Publication Date
- 2026-05-15
- Estimated Expiration
- 2042-11-01
AI Technical Summary
The target drone exhibited significant altitude dispersion during sustained high overload, affecting the assessment of flight test results.
By establishing a height control loop for the target drone, the height overload command is calculated. Combining the longitudinal and lateral overload commands, the control parameters of the autopilot control system are designed to achieve a smooth roll angle command and control the height change of the target drone during a large overload process.
This effectively reduces the altitude dispersion of the target drone during high overload processes, ensuring the successful completion of flight missions and the accuracy of test results.
Smart Images
Figure CN115840456B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of aerospace technology, specifically to a method for preventing target drones from falling off height under continuous high overload. Background Technology
[0002] When the target drone performs sustained high G-forces, it uses Body-to-The-Air (BTT) control to change direction by tilting the fuselage and generating lift. Based on the characteristics of BTT control, pitch and roll commands need to be synthesized from longitudinal and lateral overloads. To ensure safe flight testing and the successful completion of the flight mission during sustained high G-forces, the original altitude command is no longer tracked. To balance gravity, a longitudinal overload command of approximately 1g is typically given during sustained high G-forces to ensure flight safety during maneuvers. Lateral overload changes are minimal during sustained high G-force flight. According to the characteristics of BTT, the roll and longitudinal overload commands do not change significantly. To meet the requirements of sustained high G-force maneuvers, the overload command is tracked during these maneuvers. However, this approach has certain drawbacks. Simulation using a six-degree-of-freedom model revealed a significant dispersion in the target drone's altitude during sustained high G-forces, affecting the evaluation of flight test results. Therefore, taking appropriate measures to prevent excessive height dispersion during the continuous high overload of the target drone has become a key focus in the development of the target drone. Summary of the Invention
[0003] To address the aforementioned shortcomings of existing technologies, this invention provides a control method for preventing significant height dispersion in a target drone during sustained high overload.
[0004] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:
[0005] A method for preventing target drones from dropping height under continuous high overload is provided, which includes the following steps:
[0006] S1: Based on the aerodynamic characteristics of the target drone, the predetermined altitude command and predetermined longitudinal velocity command of the target drone trajectory are designed using a three-degree-of-freedom model.
[0007] S2: Input the predetermined height command and predetermined longitudinal velocity command into the target drone's six-degree-of-freedom model as input commands;
[0008] S3: Establish the target drone's altitude control loop and set the target drone's control gain. and The input command is input into the height control loop, and the required height overload command for height control is calculated. ;
[0009] S4: Based on the high overload command Calculate the longitudinal overload command required during the flight of the target drone. ;
[0010] S5: Based on the high overload command Calculate the roll angle command for the target drone's maneuvering phase. γ c :
[0011]
[0012] in: nzc This is a lateral overload command;
[0013] S6: Utilizing the longitudinal overload command and lateral overload command nzc Calculate pitch channel overload command ;
[0014] S7: Calculate the control parameters of the target drone's autopilot control system. , and Complete the setting of the target drone's autopilot control parameters;
[0015] S8: Roll angle command γ c Longitudinal overload command and lateral overload command The target drone is controlled by the autopilot with the input control parameters set.
[0016] Further, step S7 includes:
[0017] S71: Establish the dynamic model of the target drone:
[0018]
[0019] in: The trajectory inclination angle of the target drone. For the quality of the target machine, V For speed, For thrust, For the angle of attack, It is an axial force. For normal force, For pitch rotation inertia, For pitch rate, For pitching moment, The pitch angle;
[0020] S72: Linearize the dynamic model with small perturbations to obtain the system of differential equations:
[0021]
[0022] in, , , , , ; a 1. a 2. a 3. a 4. a All 5 are dynamic coefficients;
[0023] S73: By performing a Laplace transform on the system of differential equations and neglecting the small dynamic coefficients of the reaction body and control surfaces during the downward motion, the transfer function of the target drone's longitudinal channel can be obtained:
[0024]
[0025] S74: Design the stabilization loop for the autopilot. The open-loop transfer function of the damping loop of the stabilization loop is:
[0026]
[0027] The closed-loop transfer function of the damping circuit is:
[0028]
[0029] The open-loop transfer function of the pseudo-angle-of-attack loop is:
[0030]
[0031] The closed-loop transfer function of the pseudo-angle-of-attack loop is:
[0032]
[0033] in, The feedback gain of the angular rate feedback loop;
[0034] S75: The feedback gain is obtained using the pole placement method. and The characteristic polynomial corresponding to the ideal pole is:
[0035]
[0036] in, and These are the damping ratio and frequency corresponding to the ideal poles, respectively;
[0037] S76: Combining steps S75 and S74, we obtain:
[0038]
[0039] S77: Calculate control parameters and :
[0040]
[0041] S78: Parameters set according to the target drone autopilot control settings This improves the amplitude margin, phase margin, and rise time of the target drone's autopilot. T satisfy:
[0042]
[0043] S79: Control parameters , and The parameters are input into the target drone's autopilot control system to complete the setting of the target drone's autopilot control parameters.
[0044] Further, step S4 includes:
[0045] The target drone's entire flight process is divided into a maneuvering phase and a non-maneuvering phase. Altitude control is performed during the non-maneuvering phase. For high overload commands, the longitudinal overload command for tracking in the maneuver phase is: Therefore, the longitudinal overload commands required throughout the flight can be obtained. :
[0046]
[0047]
[0048]
[0049] in, Altitude control switching command switch, This is a switch for the longitudinal overload switching command.
[0050] Furthermore, in step S6, the pitch channel overload command The calculation method is as follows:
[0051]
[0052] Among them, the longitudinal overload command and lateral overload command nzc .
[0053] The beneficial effects of this invention are: this invention calculates the longitudinal overload command from the high overload command. As a longitudinal overload command of the control system, a relatively smooth dynamic overload command is obtained during the continuous high overload of the target drone, and then the roll angle command is obtained. This method can obtain a dynamically changing roll angle command instead of a fixed value. Simulation verification shows that this measure can keep the height of the target drone within a small dispersion range when it is under continuous high overload. Attached Figure Description
[0054] Figure 1 This is a block diagram illustrating the structural principle of the height control loop.
[0055] Figure 2 This is a block diagram illustrating the longitudinal overload structure principle of the autopilot control system.
[0056] Figure 3 This is a block diagram illustrating the principle of roll angle control in an autopilot control system.
[0057] Figure 4 This is a schematic diagram for calculating the roll angle command.
[0058] Figure 5 To pass the longitudinal overload command The calculated roll angle curve.
[0059] Figure 6 To pass the longitudinal overload command The height curve is calculated.
[0060] Figure 7 To pass the high overload command The calculated roll angle curve.
[0061] Figure 8 To pass the high overload command The height curve is calculated. Detailed Implementation
[0062] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.
[0063] The target drone's continuous high overload anti-drop control method in this scheme includes the following steps:
[0064] S1: Based on the aerodynamic characteristics of the target drone, the predetermined altitude command and predetermined longitudinal velocity command of the target drone trajectory are designed using a three-degree-of-freedom model.
[0065] S2: Input the predetermined height command and predetermined longitudinal velocity command into the target drone's six-degree-of-freedom model as input commands;
[0066] S3: As Figure 1 As shown, a height control loop for the target drone is established, and the control gain of the target drone is set. and The input command is input into the height control loop, and the required height overload command for height control is calculated. ;
[0067] S4: As Figure 2 As shown, according to the high overload command Calculate the longitudinal overload command required during the flight of the target drone. Step S4 includes:
[0068] The target drone's entire flight process is divided into a maneuvering phase and a non-maneuvering phase. Altitude control is performed during the non-maneuvering phase. For high overload commands, the longitudinal overload command for tracking in the maneuver phase is: Therefore, the longitudinal overload commands required throughout the flight can be obtained. :
[0069]
[0070]
[0071]
[0072] in, Altitude control switching command switch, This is a switch for the longitudinal overload switching command.
[0073] S5: Based on the high overload command Calculate the roll angle command for the target drone's maneuvering phase. γ c :
[0074]
[0075] in: nzc This is a lateral overload command;
[0076] S6: As Figure 4 As shown, using the longitudinal overload command and lateral overload command nzc Calculate pitch channel overload command Pitch channel overload command The calculation method is as follows:
[0077]
[0078] Among them, the longitudinal overload command and lateral overload command nzc This embodiment nzc Employing a 6g lateral overload command, It is a smoothly changing longitudinal overload command. The roll angle calculated in this way can keep the height distribution within a small range; then the roll angle command... γ c Input as follows Figure 3 Roll angle control is performed within the roll angle control system shown.
[0079] S7: Calculate the control parameters of the target drone's autopilot control system. , and Step S7 includes setting the control parameters for the target drone's autopilot;
[0080] S71: Establish the dynamic model of the target drone:
[0081]
[0082] in: The trajectory inclination angle of the target drone. For the quality of the target machine, V For speed, For thrust, For the angle of attack, It is an axial force. For normal force, For pitch rotation inertia, For pitch rate, For pitching moment, The pitch angle;
[0083] S72: Linearize the dynamic model with small perturbations to obtain the system of differential equations:
[0084]
[0085] in, , , , , ; a 1. a 2. a 3. a 4. a All 5 are dynamic coefficients;
[0086] S73: By performing a Laplace transform on the system of differential equations and neglecting the small dynamic coefficients of the reaction body and control surfaces during the downward motion, the transfer function of the target drone's longitudinal channel can be obtained:
[0087]
[0088] S74: Design the stabilization loop for the autopilot. The open-loop transfer function of the damping loop of the stabilization loop is:
[0089]
[0090] The closed-loop transfer function of the damping circuit is:
[0091]
[0092] The open-loop transfer function of the pseudo-angle-of-attack loop is:
[0093]
[0094] The closed-loop transfer function of the pseudo-angle-of-attack loop is:
[0095]
[0096] in, The feedback gain of the angular rate feedback loop;
[0097] S75: The feedback gain is obtained using the pole placement method. and The characteristic polynomial corresponding to the ideal pole is:
[0098]
[0099] in, and These are the damping ratio and frequency corresponding to the ideal poles, respectively;
[0100] S76: Combining steps S75 and S74, we obtain:
[0101]
[0102] S77: Calculate control parameters and :
[0103]
[0104] S78: Parameters set according to the target drone autopilot control settings This improves the amplitude margin, phase margin, and rise time of the target drone's autopilot. T satisfy:
[0105]
[0106] S79: Control parameters , and The parameters are input into the target drone's autopilot control system to complete the setting of the target drone's autopilot control parameters.
[0107] S8: Roll angle command γ c Longitudinal overload command and lateral overload command The target drone is controlled by the autopilot with the input control parameters set.
[0108] This embodiment uses The roll angle and height curves, verified through simulation as commands, are as follows: Figure 5 and Figure 6 As shown, with The roll angle and height curves, verified through simulation as longitudinal overload commands, are as follows: Figure 7 and Figure 8 As shown. Simulation verification shows that: root According to the original high The altitude command, through the altitude control loop, can produce a relatively smooth command. , through The roll angle command to be calculated γ c This ensures that the target drone's altitude does not diverge significantly during maneuvering, resulting in good test results and demonstrating the innovation and effectiveness of this approach.
Claims
1. A method for preventing height drop during continuous high overload control of a target drone, characterized in that, Includes the following steps: S1: Based on the aerodynamic characteristics of the target drone, the predetermined altitude command and predetermined longitudinal velocity command of the target drone trajectory are designed using a three-degree-of-freedom model. S2: Input the predetermined height command and predetermined longitudinal velocity command into the target drone's six-degree-of-freedom model as input commands; S3: Establish the target drone's altitude control loop and set the target drone's control gain. and The input command is input into the height control loop, and the required height overload command for height control is calculated. ; S4: Based on the high overload command Calculate the longitudinal overload command required during the flight of the target drone. ; S5: Based on the high overload command Calculate the roll angle command for the target drone's maneuvering phase. γ c : in: nzc This is a lateral overload command; S6: Utilizing the longitudinal overload command and lateral overload command nzc Calculate pitch channel overload command ; S7: Calculate the control parameters of the target drone's autopilot control system. , and Complete the setting of the target drone's autopilot control parameters; S8: Roll angle command γ c Longitudinal overload command and lateral overload command The target drone is controlled by the autopilot with the input control parameters set.
2. The target drone continuous high overload anti-drop control method according to claim 1, characterized in that, Step S7 includes: S71: Establish the dynamic model of the target drone: in: The trajectory angle of the target drone. For the quality of the target machine, V For speed, For thrust, For the angle of attack, It is an axial force. For normal force, For pitch rotation inertia, For pitch rate, For pitching moment, The pitch angle; S72: Linearize the dynamic model with small perturbations to obtain the system of differential equations: in, , , , , ; a 1. a 2. a 3. a 4. a All 5 are kinetic coefficients; S73: By performing a Laplace transform on the system of differential equations and neglecting the small dynamic coefficients of the reaction body and control surfaces during the downward motion, the transfer function of the target drone's longitudinal channel can be obtained: S74: Design the stabilization loop for the autopilot. The open-loop transfer function of the damping loop of the stabilization loop is: The closed-loop transfer function of the damping circuit is: The open-loop transfer function of the pseudo-angle-of-attack loop is: The closed-loop transfer function of the pseudo-angle-of-attack loop is: in, The feedback gain of the angular rate feedback loop; S75: The feedback gain is obtained using the pole placement method. and The characteristic polynomial corresponding to the ideal pole is: in, and These are the damping ratio and frequency corresponding to the ideal poles, respectively; S76: Combining steps S75 and S74, we obtain: S77: Calculate control parameters and : S78: Parameters set according to the target drone autopilot control settings This improves the amplitude margin, phase margin, and rise time of the target drone's autopilot. T satisfy: S79: Control parameters , and The parameters are input into the target drone's autopilot control system to complete the setting of the target drone's autopilot control parameters.
3. The target drone continuous high overload anti-drop control method according to claim 1, characterized in that, Step S4 includes: The target drone's entire flight process is divided into a maneuvering phase and a non-maneuvering phase. Altitude control is performed during the non-maneuvering phase. For high overload commands, the longitudinal overload command for tracking in the maneuver phase is: Therefore, the longitudinal overload commands required throughout the flight can be obtained. : in, Altitude control switching command switch, This is a switch for the longitudinal overload switching command.
4. The target drone continuous high overload anti-drop control method according to claim 1, characterized in that, In step S6, the pitch channel overload command The calculation method is as follows: Among them, the longitudinal overload command and lateral overload command nzc .