A six-degree-of-freedom flight trajectory prediction method and device

Abstract

The present application belongs to the field of flight control technology, and particularly relates to a six-degree-of-freedom flight trajectory prediction method and device. The method includes step S1, obtaining the initial value of the inertial link, the initial value of the high-pass link and the initial value of the second-order link given by the aircraft automatic flight control system and the main flight control system, obtaining the control surface position output by the servo, obtaining the motion parameters output by the aircraft sensor, obtaining the throttle lever position output by the engine, and obtaining the own fuel information output by the aircraft; step S2, using the above parameters as initial values, based on the preset virtual system automatic flight control system model, the six-degree-of-freedom equation model is used for motion solution, the solution result is fed back to the automatic flight control system model, and the process is repeated until the motion trajectory of the aircraft in the set time period is given; step S3, based on the predicted motion trajectory, anti-collision ground evaluation is performed. The present application can realize the real-time prediction of the flight trajectory with high prediction accuracy.

Description

Technical Field

[0001] The present application belongs to the field of flight control technology, and in particular relates to a six-degree-of-freedom flight trajectory prediction method and device. Background Art

[0002] Both civil and military aircraft are important national assets, and the loss of them will bring serious consequences. Therefore, countries around the world are actively conducting research on automatic ground collision avoidance, and trajectory prediction is the basis of automatic ground collision avoidance.

[0003] Trajectory prediction can predict the flight status of an aircraft in the future, which is of great significance for collision avoidance assessment. Traditional three-degree-of-freedom prediction only considers the aircraft's kinematic information, which is not enough to support relatively accurate trajectory prediction. Summary of the invention

[0004] In order to solve the above problems, the present application provides a six-degree-of-freedom flight trajectory prediction method and device, which are applied to flight control systems that have high accuracy requirements for trajectory prediction.

[0005] The first aspect of the present application provides a six-degree-of-freedom flight trajectory prediction method, which mainly includes:

[0006] Step S1, obtaining the initial values ​​of the inertia link, the high-pass link and the second-order link given by the aircraft automatic flight control system and the main flight control system, obtaining the control surface position output by the steering gear, obtaining the motion parameters output by the aircraft sensor, obtaining the throttle lever position output by the engine, and obtaining the own fuel quantity information output by the aircraft;

[0007] Step S2, predicting the motion trajectory of the subsequent set time period based on the preset virtual system, wherein the virtual system includes an automatic flight control system model, a main flight control system model, a steering gear model, a wind aerodynamic model, a six-degree-of-freedom equation model and an engine model, the automatic flight control system model and the main flight control system model are initialized using the initial values ​​of the inertia link, the initial values ​​of the high-pass link and the initial values ​​of the second-order link, the position of the rudder surface is used as the initial value of the steering gear model, the motion parameters and the oil quantity information are used as the initial values ​​of the six-degree-of-freedom equation model, and the throttle lever position is used as the initial value of the engine model. After the initial values ​​are input, the virtual system performs self-circulation calculation. The automatic flight control system model calculates the longitudinal control amount, the lateral control amount and the throttle stick instruction based on the received normal overload instruction, the roll angle instruction and the speed instruction. The main flight control system model calculates the rudder surface instruction based on the longitudinal control amount and the lateral control amount. The servo model outputs the rudder surface deflection according to the rudder surface instruction, and outputs the aerodynamic force based on the wind aerodynamic model. The engine model outputs the control parameters according to the throttle stick instruction. The six-degree-of-freedom equation model performs motion solution based on the control parameters and the aerodynamic force, and feeds back the solution results to the automatic flight control system model and the main flight control system model until the motion trajectory of the aircraft in the set time period is predicted.

[0008] Step S3: perform anti-collision assessment based on the predicted motion trajectory.

[0009] Preferably, in step S1, the motion parameters include three-axis speed, three-axis position, three-axis angular velocity and three attitude angles.

[0010] Preferably, in step S2, the set time period is 10s to 20s.

[0011] The second aspect of the present application provides a six-degree-of-freedom flight trajectory prediction device, which mainly includes:

[0012] The real aircraft parameter acquisition module is used to obtain the initial values ​​of the inertia link, the high-pass link and the second-order link given by the aircraft automatic flight control system and the main flight control system, obtain the control surface position output by the servo, obtain the motion parameters output by the aircraft sensor, obtain the throttle lever position output by the engine, and obtain the aircraft's own fuel information output by the aircraft;

[0013] The motion trajectory prediction module is used to predict the motion trajectory of the subsequent set time period based on the preset virtual system, wherein the virtual system includes an automatic flight control system model, a main flight control system model, a steering gear model, a wind aerodynamic model, a six-degree-of-freedom equation model and an engine model. The automatic flight control system model and the main flight control system model are initialized with the initial values ​​of the inertia link, the initial values ​​of the high-pass link and the initial values ​​of the second-order link, the position of the rudder surface is used as the initial value of the steering gear model, the motion parameters and the oil quantity information are used as the initial values ​​of the six-degree-of-freedom equation model, and the throttle lever position is used as the initial value of the engine model. After the initial values ​​are input, the virtual system performs automatic Cyclic calculation, the automatic flight control system model calculates the longitudinal control amount, lateral control amount and throttle lever instruction based on the received normal overload instruction, roll angle instruction and speed instruction, the main flight control system model calculates the rudder surface instruction based on the longitudinal control amount and the lateral control amount, the servo model outputs the rudder surface deflection according to the rudder surface instruction, and outputs the aerodynamic force based on the wind aerodynamic model, the engine model outputs the control parameter according to the throttle lever instruction, the six-degree-of-freedom equation model performs motion solution based on the control parameter and the aerodynamic force, and feeds the solution result back to the automatic flight control system model and the main flight control system model until the motion trajectory of the aircraft in the set time period is predicted;

[0014] The anti-collision assessment module is used to perform anti-collision assessment based on the predicted motion trajectory.

[0015] Preferably, the motion parameters include three-axis speed, three-axis position, three-axis angular velocity and three attitude angles.

[0016] Preferably, the set time period is 10s to 20s.

[0017] The present application can realize the real-time prediction of the flight trajectory. The prediction result gives the altitude change of the aircraft during the ascent process. The present application has a high prediction accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a data flow diagram of a preferred embodiment of the six-degree-of-freedom flight trajectory prediction method of the present application.

[0019] Figure 2 It is a schematic diagram of trajectory prediction simulation. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0021] The first aspect of the present application provides a six-degree-of-freedom flight trajectory prediction method, such as Figure 1 As shown, it mainly includes:

[0022] Step S1, obtaining the initial values ​​of the inertia link, the high-pass link and the second-order link given by the aircraft automatic flight control system and the main flight control system, obtaining the control surface position output by the steering gear, obtaining the motion parameters output by the aircraft sensor, obtaining the throttle lever position output by the engine, and obtaining the own fuel quantity information output by the aircraft;

[0023] Step S2, predicting the motion trajectory of the subsequent set time period based on the preset virtual system, wherein the virtual system includes an automatic flight control system model, a main flight control system model, a steering gear model, a wind aerodynamic model, a six-degree-of-freedom equation model and an engine model, the automatic flight control system model and the main flight control system model are initialized using the initial values ​​of the inertia link, the initial values ​​of the high-pass link and the initial values ​​of the second-order link, the position of the rudder surface is used as the initial value of the steering gear model, the motion parameters and the oil quantity information are used as the initial values ​​of the six-degree-of-freedom equation model, and the throttle lever position is used as the initial value of the engine model. After the initial values ​​are input, the virtual system performs self-circulation calculation. The automatic flight control system model calculates the longitudinal control amount, the lateral control amount and the throttle stick instruction based on the received normal overload instruction, the roll angle instruction and the speed instruction. The main flight control system model calculates the rudder surface instruction based on the longitudinal control amount and the lateral control amount. The servo model outputs the rudder surface deflection according to the rudder surface instruction, and outputs the aerodynamic force based on the wind aerodynamic model. The engine model outputs the control parameters according to the throttle stick instruction. The six-degree-of-freedom equation model performs motion solution based on the control parameters and the aerodynamic force, and feeds back the solution results to the automatic flight control system model and the main flight control system model until the motion trajectory of the aircraft in the set time period is predicted.

[0024] Step S3: perform anti-collision assessment based on the predicted motion trajectory.

[0025] First reference Figure 1 The dotted box in the upper part is a virtual system, which includes several virtual models. These virtual models are designed according to the airborne system and transfer data between them. Figure 1 The lower part is the real software and hardware structure of the aircraft. The automatic flight control system of the real aircraft sends the longitudinal control amount and the lateral control amount to the main flight control system according to the normal overload command and the roll angle command. The main flight control system outputs the various control surface commands required for flight control. Under the action of real aerodynamic force, the aircraft performs displacement and rotation movements.

[0026] In the real software and hardware structure of the aircraft, in each operation cycle, the automatic flight control system and the main flight control system output the initial values ​​of the inertial link, high-pass link, and second-order link contained therein; the servo outputs its control surface position feedback; the real sensor of the aircraft outputs the motion parameters corresponding to the aircraft movement. In some optional implementations, the motion parameters include three-axis speed, three-axis position, three-axis angular velocity, and three attitude angles; the engine outputs the position of the throttle lever; and the aircraft outputs its own fuel information. Then, in each prediction cycle, the virtual system assigns the above parameters as initial values ​​to each virtual model, and performs multi-shot non-real-time calculations according to the normal overload instructions (assuming 4g~5g) and slope instructions (generally zero) used by the aircraft to pull up. In some optional implementations, the set time period is 10s~20s. Assuming that the prediction is performed for 10 seconds, the motion trajectory of the aircraft in the next 10 seconds can be obtained. The operation trajectory is usually represented by latitude, longitude and altitude. In the next prediction cycle, repeat the above process to continuously predict the flight trajectory. Finally, in step S3, according to the predicted latitude, longitude and altitude, combined with the digital terrain, an anti-collision ground assessment can be performed.

[0027] Figure 2 A simulation example is given. Assume that the aircraft is diving at a dive angle of -20 degrees, the roll angle is zero, and the pull-up overload is 5g. Assume that 800 points are predicted, and the interval between each point is 12.5 milliseconds. From the results, it can be seen that after the aircraft starts to pull up, the aircraft altitude decreases by about 150 meters. The prediction results give the altitude change of the aircraft during the pull-up process.

[0028] In some optional implementations, in step S1, the motion parameters include three-axis speed, three-axis position, three-axis angular velocity and three attitude angles.

[0029] The second aspect of the present application provides a six-degree-of-freedom flight trajectory prediction device corresponding to the above method, mainly comprising:

[0030] The real aircraft parameter acquisition module is used to obtain the initial values ​​of the inertia link, the high-pass link and the second-order link given by the aircraft automatic flight control system and the main flight control system, obtain the control surface position output by the servo, obtain the motion parameters output by the aircraft sensor, obtain the throttle lever position output by the engine, and obtain the aircraft's own fuel information output by the aircraft;

[0031] The motion trajectory prediction module is used to predict the motion trajectory of the subsequent set time period based on the preset virtual system, wherein the virtual system includes an automatic flight control system model, a main flight control system model, a steering gear model, a wind aerodynamic model, a six-degree-of-freedom equation model and an engine model. The automatic flight control system model and the main flight control system model are initialized with the initial values ​​of the inertia link, the initial values ​​of the high-pass link and the initial values ​​of the second-order link, the position of the rudder surface is used as the initial value of the steering gear model, the motion parameters and the oil quantity information are used as the initial values ​​of the six-degree-of-freedom equation model, and the throttle lever position is used as the initial value of the engine model. After the initial values ​​are input, the virtual system performs automatic Cyclic calculation, the automatic flight control system model calculates the longitudinal control amount, lateral control amount and throttle lever instruction based on the received normal overload instruction, roll angle instruction and speed instruction, the main flight control system model calculates the rudder surface instruction based on the longitudinal control amount and the lateral control amount, the servo model outputs the rudder surface deflection according to the rudder surface instruction, and outputs the aerodynamic force based on the wind aerodynamic model, the engine model outputs the control parameter according to the throttle lever instruction, the six-degree-of-freedom equation model performs motion solution based on the control parameter and the aerodynamic force, and feeds the solution result back to the automatic flight control system model and the main flight control system model until the motion trajectory of the aircraft in the set time period is predicted;

[0032] The anti-collision assessment module is used to perform anti-collision assessment based on the predicted motion trajectory.

[0033] In some optional implementations, the motion parameters include three-axis speed, three-axis position, three-axis angular velocity and three attitude angles.

[0034] In some optional implementations, the set time period is 10s to 20s.

[0035] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A six-degree-of-freedom flight trajectory prediction method, characterized in that: include: Step S1, obtaining the initial values ​​of the inertia link, the high-pass link and the second-order link given by the aircraft automatic flight control system and the main flight control system, obtaining the control surface position output by the steering gear, obtaining the motion parameters output by the aircraft sensor, obtaining the throttle lever position output by the engine, and obtaining the own fuel quantity information output by the aircraft; Step S2, predicting the motion trajectory of the subsequent set time period based on the preset virtual system, wherein the virtual system includes an automatic flight control system model, a main flight control system model, a steering gear model, a wind aerodynamic model, a six-degree-of-freedom equation model and an engine model, the automatic flight control system model and the main flight control system model are initialized using the initial values ​​of the inertia link, the initial values ​​of the high-pass link and the initial values ​​of the second-order link, the position of the rudder surface is used as the initial value of the steering gear model, the motion parameters and the oil quantity information are used as the initial values ​​of the six-degree-of-freedom equation model, and the throttle lever position is used as the initial value of the engine model. After the initial values ​​are input, the virtual system performs self-circulation calculation. The automatic flight control system model calculates the longitudinal control amount, the lateral control amount and the throttle stick instruction based on the received normal overload instruction, the roll angle instruction and the speed instruction. The main flight control system model calculates the rudder surface instruction based on the longitudinal control amount and the lateral control amount. The servo model outputs the rudder surface deflection according to the rudder surface instruction, and outputs the aerodynamic force based on the wind aerodynamic model. The engine model outputs the control parameters according to the throttle stick instruction. The six-degree-of-freedom equation model performs motion solution based on the control parameters and the aerodynamic force, and feeds back the solution results to the automatic flight control system model and the main flight control system model until the motion trajectory of the aircraft in the set time period is predicted. Step S3: perform anti-collision assessment based on the predicted motion trajectory.

2. The six-degree-of-freedom flight trajectory prediction method according to claim 1, characterized in that: In step S1, the motion parameters include three-axis speed, three-axis position, three-axis angular velocity and three attitude angles.

3. The six-degree-of-freedom flight trajectory prediction method according to claim 1, characterized in that: In step S2, the set time period is 10s to 20s.

4. A six-degree-of-freedom flight trajectory prediction device, characterized in that: include: The real aircraft parameter acquisition module is used to obtain the initial values ​​of the inertia link, the high-pass link and the second-order link given by the aircraft automatic flight control system and the main flight control system, obtain the control surface position output by the servo, obtain the motion parameters output by the aircraft sensor, obtain the throttle lever position output by the engine, and obtain the aircraft's own fuel information output by the aircraft; The motion trajectory prediction module is used to predict the motion trajectory of the subsequent set time period based on the preset virtual system, wherein the virtual system includes an automatic flight control system model, a main flight control system model, a steering gear model, a wind aerodynamic model, a six-degree-of-freedom equation model and an engine model. The automatic flight control system model and the main flight control system model are initialized with the initial values ​​of the inertia link, the initial values ​​of the high-pass link and the initial values ​​of the second-order link, the position of the rudder surface is used as the initial value of the steering gear model, the motion parameters and the oil quantity information are used as the initial values ​​of the six-degree-of-freedom equation model, and the throttle lever position is used as the initial value of the engine model. After the initial values ​​are input, the virtual system performs automatic Cyclic calculation, the automatic flight control system model calculates the longitudinal control amount, lateral control amount and throttle lever instruction based on the received normal overload instruction, roll angle instruction and speed instruction, the main flight control system model calculates the rudder surface instruction based on the longitudinal control amount and the lateral control amount, the servo model outputs the rudder surface deflection according to the rudder surface instruction, and outputs the aerodynamic force based on the wind aerodynamic model, the engine model outputs the control parameter according to the throttle lever instruction, the six-degree-of-freedom equation model performs motion solution based on the control parameter and the aerodynamic force, and feeds the solution result back to the automatic flight control system model and the main flight control system model until the motion trajectory of the aircraft in the set time period is predicted; The anti-collision assessment module is used to perform anti-collision assessment based on the predicted motion trajectory.

5. The six-degree-of-freedom flight trajectory prediction device according to claim 4, characterized in that: The motion parameters include three-axis speed, three-axis position, three-axis angular speed and three attitude angles.

6. The six-degree-of-freedom flight trajectory prediction device according to claim 4, characterized in that: The set time period is 10s to 20s.

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