Ground rapid trimming method for flight simulator equipment

Abstract

The invention belongs to the technical field of flight simulator ground balancing, particularly relates to a rapid ground balancing method for flight simulator equipment, and aims to solve the problems of overlong ground balancing time and low efficiency of a traditional flight simulator. According to the method, the static landing gear compression amount is determined by obtaining the airport environment, the simulator body and landing gear tire parameters and constructing a spring oil damping model, the initial terrain clearance difference is calculated in combination with coordinate system transformation and a vertical distance formula, the initial balancing height value of the gravity center of the flight simulator is obtained, and based on the dynamic landing gear compression amount, the flight simulator body and the landing gear tire parameters are calculated. Calculating longitudinal, lateral and normal forces of the ground in a sectional manner to obtain a total force and a total moment of the ground borne by the aircraft, and obtaining a total stress and a total moment of an aircraft body shaft; and iteratively solving an aircraft attitude angle by using a gradient descent method, setting the aircraft attitude angle to a flight simulator, and taking total stress and total moment return-to-zero as a convergence condition. According to the method, the ground balancing time is remarkably shortened, and the use efficiency and training response speed of the flight simulator are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of ground trimming of flight simulators, and particularly relates to a method for rapid ground trimming of flight simulator equipment. Background Art

[0002] Ground trimming of a flight simulator is a mechanical trimming method on the ground when the aircraft is repositioned to the aircraft takeoff position, and it is necessary to solve the force balance of thrust, ground force, and gravity, so as to obtain the parameters that the aircraft needs to set: the height of the aircraft from the ground and the attitude angle of the aircraft.

[0003] Currently, the traditional ground trimming method of a simulator is to construct an aircraft ground handling characteristics model and continuously iterate and adjust the aircraft attitude angle and height from the ground, so that the total force and total moment are balanced, thereby achieving ground trimming.

[0004] However, the aircraft ground handling characteristics model involves the interaction between the landing gear, tires and the ground, and the mathematical model is complex. The trimming needs to strictly follow a fixed process: first configure the airport of the visual system, then set the aircraft system parameters, and finally solve the force balance. This makes the traditional iterative trimming method have significant defects in engineering practice: strong dependence between steps, and it is necessary to wait for the previous step to be completed before proceeding; the number of iterations for force balance calculation is large, and the ground trimming takes a long time. In addition, in order to avoid abnormal overflow of parameter calculation, it is necessary to manually set the initial height value in the database, and manually debug according to the height of different airport visuals, with extremely low efficiency, and it is difficult to adapt to the high-efficiency training requirements of the simulator, and technical improvement is urgently needed. Summary of the Invention

[0005] In order to solve the above problems in the prior art, that is, the traditional ground trimming of a flight simulator has a long trimming time and low efficiency due to a complex model, strong step dependence, a large number of iterations, and the need for manual debugging of the initial height, in the first aspect of the present invention, a method for rapid ground trimming of flight simulator equipment is proposed, and the method includes the following steps: Obtain initial parameters related to ground trimming of the flight simulator, where the initial parameters include: airport environment parameters, flight simulator body parameters, and structural characteristic parameters of the landing gear and tires; Calculate the gravity of the flight simulator according to the flight simulator body parameters, construct a spring-oil damping model of the landing gear strut force, and then determine the static landing gear compression amount according to the force balance condition under the ground equilibrium state; Determine the coordinates of the lowest point of the landing gear in the earth coordinate system, and obtain the dynamic landing gear compression amount through transformation; Based on the static landing gear compression amount, combined with the vertical distance of the tire contact point in the body axis coordinate system when the landing gear is fully extended naturally, calculate the initial height difference at the center of gravity of the flight simulator; Add the initial ground clearance difference at the center of gravity of the flight simulator to the ground height to obtain the initial trim height value of the center of gravity of the flight simulator and set it in the flight simulator; based on the dynamic landing gear compression amount, calculate the ground longitudinal force, lateral force, and normal force through segmented calculation to obtain the total ground force and total moment acting on the aircraft, and based on the total ground force and total moment, and other forces acting on the aircraft, obtain the total force and total moment acting on the aircraft body axis; Read the runway information, motion state information, and aircraft force information, and combine the total force and total moment acting on the aircraft body axis to solve for the attitude angle vector of the aircraft and set it in the flight simulator to complete the ground trim of the flight simulator.

[0006] In some preferred embodiments, the static landing gear compression amount is determined according to the force balance condition, and the method is as follows: When the aircraft is in a static ground equilibrium state, the oil damping force is zero, and the landing gear strut force is equal to the gravity and the air spring force. The static landing gear compression amount is: ; ; ; In the formula, is the gravity, is the mass of the aircraft, is the acceleration due to gravity, is the cylinder volume when the strut is not compressed, is the buffer cylinder volume, is the cross-sectional area of the cylinder, is the static landing gear compression amount, is the buffer strut compression amount, is the cylinder pre-charge pressure, is the cylinder pressure, P0V0 = PV = cste, V = V 0− A ⋅ D， ， That is, the spring oil damping model ， is the landing gear strut force, is the air spring force, is the oil damping force 。

[0007] In some preferred embodiments, the method for determining the coordinates of the lowest point of the landing gear in the geodetic coordinate system and obtaining the dynamic landing gear compression amount through transformation is as follows: ; ; In the formula, is the coordinate of the wheel center in the body axis coordinate system when the landing gear is fully extended naturally, is the tire rolling radius, is the coordinate of the aircraft center of gravity in the earth coordinate system, is the dynamic compression of the landing gear, is a sub-item in the direction cosine matrix.

[0008] In some preferred embodiments, the initial height difference from the ground at the center of gravity of the flight simulator is calculated as follows: ; ; ; wherein, is the coordinate of the tire contact point in the body axis coordinate system when the landing gear is fully extended naturally.

[0009] In some preferred embodiments, based on the dynamic compression of the landing gear, the longitudinal, lateral, and normal ground forces are calculated by a segmented method, and the method is as follows: The normal force is calculated based on the dynamic compression of the landing gear through a spring-oil damper model; the normal force includes the tire / landing gear normal strut force ; the includes the air spring force and the landing gear damping force; the landing gear damping force is obtained by multiplying by the damping coefficient; , is the compression rate of the landing gear strut, is the pitch angular velocity of the aircraft, is the roll angular velocity of the aircraft, is the height change rate; The lateral force includes the tire lateral force, and its calculation method is as follows: ; ; ; ; ; In the formula, is the lateral force exerted by the ground on the aircraft tire, is the tire / landing gear normal strut force, is the effective friction coefficient, is the lateral force attenuation coefficient, is, is the side force ratio, is the tire sideslip angle, is the sideslip angle ratio, is, is the sideslip ratio symbol, is the turning gain; The ground longitudinal force is calculated as follows: Under the ground trim condition, based on the condition that the turning angle is zero, according to the constraint conditions that the engine idle thrust is less than or equal to the maximum static friction and the ground longitudinal force is less than or equal to the maximum static friction, calculate the ground longitudinal force: ; In the formula, is obtained by multiplying by the effective friction coefficient.

[0010] In some preferred embodiments, the calculation method of the total ground force and total moment is as follows: Calculate the forces on the landing gear in the body axis coordinate system through coordinate transformation: ; In the formula, is the transformation matrix from the NED coordinate system to the body axis coordinate system, is the transformation matrix from the wheel coordinate system to the NED coordinate system, is the force in the wheel coordinate system; The is calculated through the deflection angle Specifically: ; The component of the moment on the landing gear in the body axis is calculated by the following formula: ; Among them, is the position vector of the single tire contact point in the body axis coordinate system, is the component of the single tire in the body axis; The total force on the aircraft body axis is the sum of the other forces on the aircraft and the total ground force: ; The total moment on the aircraft body axis is the sum of the other moments on the aircraft and the total ground moment: ; In the formula, , both include the engine thrust and the aircraft gravity.

[0011] In some preferred embodiments, if the force in the wheel coordinate system includes the longitudinal force and the lateral force and the normal force , then the forces in the wheel coordinate system are as follows: ; If F is the unit force in the Y-axis direction in the wheel coordinate system, is the installation angle of the landing gear strut, is the front wheel deflection angle, and the components of the ground force F in the body axis are: .

[0012] In some preferred embodiments, the calculation method of the deflection angle is as follows: ; ; In the formula, , is the transformation matrix from the body axis coordinate system to the NED coordinate system, and the components of the ground force F in the NED coordinate system and the body axis coordinate system are respectively and .

[0013] The components of the ground force F in the NED coordinate system and the body axis coordinate system are respectively and : ; In the formula, is the transformation matrix from the body axis coordinate system to the NED coordinate system.

[0014] In some preferred embodiments, the method for obtaining the position vector of the single tire contact point in the body axis coordinate system is as follows: Assume that the wheel center coordinates when the landing gear is in its natural extended state are , the tire rolling radius is , the landing gear compression amount is , is or Then the position vector of the single tire contact point is: .

[0015] In some preferred embodiments, the method for solving the attitude angle vector of the aircraft and setting it to the flight simulator to complete the ground trimming of the flight simulator is as follows: Read the runway information, motion state information, and aircraft force information to obtain the aircraft attitude angle vector , where For height, is the pitch angle, is the roll angle, is the yaw angle, and iteration parameters are set, where the iteration parameters include a weight coefficient vector, a learning rate, and a termination condition parameter; Based on the aircraft attitude angle vector and the weight coefficient vector, calculate the cost function value, , where the weight coefficient vector , the total force vector on the aircraft body axis , the total moment vector on the aircraft body axis ; Based on the aircraft attitude angle vector and the cost function value, perform gradient vector calculation to obtain the gradient value: ; ; ; Based on the current aircraft attitude angle vector , the gradient vector , the learning rate , iterate the state vector according to a preset threshold as the termination condition, ; the preset threshold includes a cost function change threshold, a gradient threshold, and a maximum number of iterations; When the termination condition is met, obtain the optimized aircraft attitude angle vector and set it to the flight simulator, and the total force and total moment on the aircraft body axis are zero, completing the ground trimming of the flight simulator.

[0016] Advantages of the present invention: By obtaining airport environment, simulator body and landing gear tire parameters, constructing a spring oil damper model to determine the static landing gear compression amount, and combining coordinate transformation and vertical distance formula to calculate the initial ground clearance difference, and then obtaining the initial trimming height value of the flight simulator center of gravity. This process gets rid of traditional manual debugging, realizes automatic and accurate calculation of the initial height, and avoids human setting errors; Based on the landing gear compression amount, calculate the ground longitudinal, lateral, and normal forces in a segmented manner, and obtain the stiffness coefficient by combining with a real-time interpolation table, improving the calculation accuracy of the mechanical model. At the same time, through coordinate transformation and moment synthesis algorithm, efficiently calculate the total ground force and total moment on the aircraft, and then obtain the total force and total moment under the aircraft body axis system; Use the gradient descent method to iteratively solve the aircraft attitude angle, with the termination condition as the convergence condition, replacing the traditional step-by-step iteration method. This method has fully automated data processing and parameter solution, greatly reducing the dependence on manual intervention during the trimming process, avoiding waiting delays between steps and mechanical balance iteration redundancy, significantly shortening the ground trimming time compared with the traditional method, and effectively improving the use efficiency and training response speed of the flight simulator. Description of the Drawings

[0017] Other features, objectives, and advantages of the present application will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings: Figure 1 It is a flowchart of the steps of the ground rapid trimming method of the flight simulator device of the present invention. Detailed implementation manners

[0018] The present application will be further described in detail below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related invention and are not intended to limit the invention. Additionally, it should be noted that for the sake of description, only parts related to the relevant invention are shown in the drawings.

[0019] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0020] For a clearer description of the ground rapid trimming method of the flight simulator device of the present invention, the following will be combined with Figure 1 Each step in the embodiments of the present invention will be described in detail.

[0021] The present invention proposes a ground rapid trimming method for a flight simulator device. Referring to Figure 1 , the method includes the following steps: Obtain initial parameters related to the ground trimming of the flight simulator. The initial parameters include: airport environment parameters, flight simulator body parameters, and structural characteristic parameters of the landing gear and tires; In this embodiment, the airport environment parameters include airport runway information, which is obtained by loading the visual system through a database and can read the sea-level pressure altitude of the current airport runway; The flight simulator body parameters include the throttle lever position / aircraft environmental mass, which is obtained through the shared memory of the instructor station software; The structural characteristic parameters of the landing gear and tires include the geometric characteristics of the landing gear / tires (such as dimensions / sizes), the stiffness coefficients and damping coefficients of the landing gear struts / tires, and the friction coefficient, which are obtained by reading and querying the difference data table Calculate the gravity of the flight simulator according to the flight simulator body parameters, construct a spring-oil damping model of the landing gear strut force, and then, under the ground equilibrium state, determine the static landing gear compression amount according to the force balance condition; In this embodiment, the method for determining the static landing gear compression amount according to the force balance condition is as follows: The spring-oil damping model is: ; Wherein, is the landing gear strut force, is the air spring force, is the oil damping force; When the aircraft is in a static equilibrium state on the ground, the oil damping force is zero, and the landing gear strut force is equal to the gravity and the air spring force. The static landing gear compression is: ; ; ; In the formula, is the gravity, is the mass of the aircraft, is the acceleration due to gravity, is the volume of the cylinder when the strut is not compressed, is the volume of the buffer cylinder, is the cross-sectional area of the cylinder, is the static landing gear compression, is the buffer strut compression, is the pre-charge pressure of the cylinder, is the cylinder pressure, P0V0 = PV = cste, V = V 0−A⋅D; The method for determining the coordinates of the lowest point of the landing gear in the earth coordinate system and obtaining the dynamic landing gear compression through transformation is as follows: ; ; In the formula, is the coordinate of the wheel center in the body axis coordinate system when the landing gear is fully extended naturally, is the rolling radius of the tire, is the coordinate of the aircraft center of gravity in the earth coordinate system, is the dynamic landing gear compression, is the sub-item in the direction cosine matrix; Based on the static landing gear compression, combined with the vertical distance of the tire contact point in the body axis coordinate system when the landing gear is fully extended naturally, calculate the initial height difference from the ground at the center of gravity of the flight simulator. The calculation method is as follows: The coordinate of the tire contact point in the body axis coordinate system when the landing gear is fully extended naturally is: : ; The calculation formula for the vertical distance is: ; Substitute the static landing gear compression into the vertical distance formula to obtain the initial height difference from the ground at the center of gravity of the flight simulator: ; It also includes calculating the compression rate of the landing gear strut: ; In the formula: is the compression rate of the landing gear strut, is the pitch angular velocity of the aircraft, is the roll angular velocity of the aircraft, is the rate of change of altitude; Add the initial ground clearance difference at the center of gravity of the flight simulator and the ground altitude, obtain the initial trim altitude value of the center of gravity of the flight simulator and set it to the flight simulator; Based on the dynamic landing gear compression amount, calculate the ground longitudinal force, lateral force, and normal force through segmented calculation to obtain the total ground force and total moment received by the aircraft, and based on the total ground force and total moment, and other forces on the aircraft, obtain the total force and total moment on the aircraft body axis; In this embodiment, the normal force is calculated based on the landing gear compression amount through a spring-oil damper model; the normal force includes the tire / landing gear normal strut force ; the includes the air spring force and the landing gear damping force; the air spring force is obtained by using the calculation method; the landing gear damping force is obtained by multiplying by the damping coefficient; The lateral force includes the tire lateral lateral force, and its calculation method is: ; ; ; ; ; In the formula, is the lateral force exerted by the ground on the aircraft tire, is the tire / landing gear normal strut force, is the effective friction coefficient, and its value is related to the braking force ratio as shown in Table 1, is the side force attenuation coefficient, is, is the side force ratio, is the tire sideslip angle, is the sideslip angle ratio, is, is the sideslip ratio symbol. When >0, =1; when <0, = -1. It is generally considered that when, the tire does not slip; when, the tire slips, is the turning gain; Table 1

[0022] Turning gain is: ; wherein, is the reference friction coefficient, see Table 2, N64 is the R-64 turning power, calculated by the following formula: ; ; wherein, is the turning power coefficient, is the actual tire pressure, is the rated tire pressure, is the tire width; Table 2:

[0023] The ground longitudinal force, its calculation method is: Under the ground trim state, based on the condition that the turning angle is zero, according to the constraint conditions that the engine idle thrust is less than or equal to the maximum static friction force and the ground longitudinal force is less than or equal to the maximum static friction force, calculate the ground longitudinal force: ; In the formula, is obtained by multiplying by the effective friction coefficient; Based on the ground longitudinal force, lateral force, and normal force, calculate the total ground force and total moment of the landing gear about the body axis; In this embodiment, the calculation method of the total ground force and total moment is: Calculate the forces on the landing gear in the body axis coordinate system through coordinate transformation: ; In the formula, is the transformation matrix from the NED coordinate system to the body axis coordinate system, is the transformation matrix from the wheel coordinate system to the NED coordinate system, is the force in the wheel coordinate system; The [[ID=7%]] is calculated through the deflection angle Specifically: ; The components of the ground force F in the NED coordinate system and the body-axis coordinate system are respectively and ; ; wherein, is the transformation matrix from the body-axis coordinate system to the NED coordinate system; then, the yaw angle is calculated by the following formula: ; wherein, is the in the NED coordinate system x and y components.

[0024] If F is the unit force in the Y-axis direction in the wheel coordinate system, is the installation angle of the landing gear strut, is the nose wheel yaw angle, and the components of the ground force F under the body axis are: ; If the forces on the wheel coordinate system include the longitudinal force , the lateral force and the normal force , then the force on the wheel coordinate system is: ; The components of the moment on the landing gear under the body axis are calculated by the following formula: ; wherein, is the position vector of the single tire contact point in the body-axis coordinate system, is the component of the single tire under the body axis, and N can be a common tricycle landing gear, which is 3 at this time; The position vector of the single tire contact point in the body-axis coordinate system is obtained through the difference data table. Specifically: assuming that the wheel center coordinate is when the landing gear is in the natural extension state, the tire rolling radius is , the landing gear compression amount is , is or then the position vector of the single tire contact point is: ; The total force on the aircraft body axis is the sum of the other forces on the aircraft and the total ground force: ; The total moment of the aircraft body axis is the sum of the other moments acting on the aircraft and the total ground moment: ; Wherein, and both include engine thrust and aircraft gravity; The runway information, motion state information, and aircraft force information are read, and the gradient descent method is used for continuous iteration until the total ground force and total moment are zero, at which point the iteration stops, and the attitude angle of the aircraft is solved. The method is as follows: Step 1: Read the runway information (position, direction, size, and the runway information affects the terrain height setting of the ground), motion state information (position, speed, acceleration, and the motion state information affects the total ground force and total moment acting on the aircraft), and aircraft force information (gravity, aerodynamic force, landing gear support force) to obtain the aircraft attitude angle vector , where For is the height, is the pitch angle, is the roll angle, is the yaw angle, and iteration parameters are set, including the weight coefficient vector, learning rate, termination condition parameter, and iteration number k; Step 2: Calculate the cost function value based on the aircraft attitude angle vector and the weight coefficient vector , where the weight coefficient vector , the total force vector of the aircraft body axis , and the total moment vector of the aircraft body axis ; Step 3: Calculate the gradient vector based on the aircraft attitude angle vector and the cost function value to obtain the gradient: ; ; ; Step 4: Based on the current aircraft attitude angle vector , the gradient vector , and the learning rate , iterate the state vector according to the preset threshold as the termination condition ; The preset threshold includes the cost function change threshold ( 1000 )), the gradient threshold (100), and the maximum number of iterations (20000); Component expansion: ; Constraint conditions: ; ; Step 5: When the termination condition is met, obtain the optimized aircraft attitude angle vector and set it to the flight simulator, so that the total force and total moment of the aircraft body axis are zero, and the ground trimming of the flight simulator is completed.

[0025] In the above embodiments, although the steps are described in the above order, those skilled in the art can understand that, in order to achieve the effects of this embodiment, different steps do not have to be executed in such an order. They can be executed simultaneously (in parallel) or in a reversed order, and these simple changes are all within the protection scope of the present invention.

[0026] Those skilled in the art should be able to realize that the modules and method steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of both. The programs corresponding to the software modules and method steps can be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium well-known in the technical field. To clearly illustrate the interchangeability of electronic hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in the form of electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0027] Terms such as "first", "second", etc. are used to distinguish similar objects, rather than to describe or represent a specific order or sequence.

[0028] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, so that a process, method, article, or device / equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent in these processes, methods, articles, or devices / equipment.

[0029] So far, the technical solution of the present invention has been described in combination with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

Claims

1. A ground rapid trimming method for flight simulator equipment, characterized in that The method includes the following steps: Obtain initial parameters related to the ground trim of the flight simulator, where the initial parameters include: airport environment parameters, flight simulator body parameters, and structural characteristic parameters of the landing gear and tires; Calculate the gravity of the flight simulator according to the flight simulator body parameters, construct a spring-oil damping model of the landing gear strut force, and then determine the static landing gear compression amount according to the force balance condition under the ground equilibrium state; Determine the coordinates of the lowest point of the landing gear in the earth coordinate system, and obtain the dynamic landing gear compression amount through transformation; Based on the static landing gear compression amount, combine the vertical distance of the tire contact point in the body axis coordinate system when the landing gear is fully extended naturally, and calculate the initial ground clearance difference at the center of gravity of the flight simulator; Add the initial ground clearance difference at the center of gravity of the flight simulator to the ground height to obtain the initial trim height value of the center of gravity of the flight simulator and set it to the flight simulator; based on the dynamic landing gear compression amount, calculate the ground longitudinal force, lateral force, and normal force through segmented calculation to obtain the total ground force and total moment received by the aircraft, and based on the total ground force and total moment, and other forces on the aircraft, obtain the total force and total moment on the aircraft body axis; Read the runway information, motion state information, and aircraft force information, combine the total force and total moment on the aircraft body axis, solve the attitude angle vector of the aircraft and set it to the flight simulator to complete the ground trim of the flight simulator.

2. The ground rapid trimming method of the flight simulator device according to claim 1, characterized in that, Determine the static landing gear compression amount according to the force balance condition, and the method is: When the aircraft is in a static equilibrium state on the ground, the oil damping force is zero, and the landing gear strut force is equal to the gravity and the air spring force. The static landing gear compression amount is: ； ； ； Wherein, is the gravity, is the mass of the aircraft, is the acceleration due to gravity, is the cylinder volume when the strut is not compressed, is the cylinder volume of the buffer, is the cross-sectional area of the cylinder, is the static compression of the landing gear, is the compression of the buffer strut, is the pre-charge pressure of the cylinder, is the cylinder pressure, P0V0 = PV = cste, V = V 0 − A ⋅ D , , that is, the spring-oil damping model, is the landing gear strut force, is the air spring force, is the oil damping force.

3. The ground rapid trimming method of the flight simulator equipment according to claim 1, characterized in that, The method for determining the coordinates of the lowest point of the landing gear in the earth coordinate system and obtaining the dynamic landing gear compression amount through transformation is: ； ； In the formula, is the coordinate of the wheel center in the body axis coordinate system when the landing gear is fully extended naturally, is the rolling radius of the tire, is the coordinate of the aircraft center of gravity in the earth coordinate system, is the dynamic compression of the landing gear, is the sub-item in the direction cosine matrix.

4. The ground rapid trimming method of the flight simulator device according to claim 3, characterized in that, The calculation method for the initial ground clearance difference at the center of gravity of the flight simulator is: ； ； ； Among them, is the coordinate of the tire contact point in the body axis coordinate system when the landing gear is fully extended naturally.

5. The ground rapid trimming method of the flight simulator device according to claim 3, characterized in that, Based on the dynamic landing gear compression amount, calculate the ground longitudinal force, lateral force, and normal force through segmented calculation, and the method is: The normal force is calculated through a spring-oil damping model based on the dynamic landing gear compression; the normal force includes the tire / landing gear normal strut force ; the includes an air spring force and a landing gear damping force; the landing gear damping force is obtained by multiplying by a damping coefficient; , is the landing gear strut compression rate, is the pitch angular velocity of the aircraft, is the roll angular velocity of the aircraft, is the height change rate; The lateral force includes the tire lateral lateral force, and the calculation method is: ； ； ； ； ； Wherein, is the lateral force exerted by the ground on the aircraft tire, is the normal strut force of the tire / landing gear, is the effective friction coefficient, is the side force attenuation coefficient, is, is the side force ratio, is the tire sideslip angle, is the sideslip angle ratio, is, is the sideslip ratio symbol, is the turning gain; The calculation method for the ground longitudinal force is: Under the ground trim state, based on the condition that the turning angle is zero, calculate the ground longitudinal force according to the constraint conditions that the engine idle thrust is less than or equal to the maximum static friction force and the ground longitudinal force is less than or equal to the maximum static friction force; ； In the formula, is obtained by multiplying with the effective friction coefficient.

6. The ground rapid trim method of the flight simulator device according to claim 1, characterized in that The calculation method for the total ground force and total moment is: Calculate the force on the landing gear in the body axis coordinate system through coordinate transformation: ； In the formula, is the transformation matrix from the NED coordinate system to the body axis coordinate system, is the transformation matrix from the wheel coordinate system to the NED coordinate system, is the force acting in the wheel coordinate system; The said is calculated by the deflection angle specifically as follows: ； The component of the moment on the landing gear in the body axis is calculated by the following formula: ； Among them, is the position vector of a single tire contact point in the body axis coordinate system, is the component of a single tire under the body axis; The total force on the aircraft body axis is the sum of other forces on the aircraft and the total ground force: ； The total moment on the aircraft body axis is the sum of other moments on the aircraft and the total ground moment: ； In the formula, and both include engine thrust and aircraft gravity.

7. The ground rapid trimming method of the flight simulator device according to claim 6, characterized in that, If the forces in the wheel coordinate system include longitudinal force , lateral force and normal force , then the forces in the wheel coordinate system are as follows: ； If F is the unit force in the Y-axis direction in the wheel coordinate system, is the installation angle of the landing gear strut, is the front wheel deflection angle, and the components of the ground force F in the body axis are: 。 8. The ground rapid trimming method of the flight simulator device according to claim 6, characterized in that The deflection angle The calculation method is as follows: ； ； In the formula, , is the transformation matrix from the body-axis coordinate system to the NED coordinate system. The components of the ground force F in the NED coordinate system and the body-axis coordinate system are respectively and .

9. The ground rapid trimming method of the flight simulator device according to claim 6, characterized in that The method for obtaining the position vector of the single tire contact point in the body axis coordinate system is: Let the coordinates of the wheel center when the landing gear extends naturally be , the rolling radius of the tire be , the compression of the landing gear be , be or Then the position vector of the contact point of a single tire is: 。 10. The ground rapid trim method of the flight simulator device according to claim 1, characterized in that The method for solving the attitude angle vector of the aircraft and setting it to the flight simulator to complete the ground trim of the flight simulator is: Read runway information, motion state information, and aircraft force information to obtain the aircraft attitude angle vector , where For altitude, is the pitch angle, is the roll angle, is the yaw angle, and set iteration parameters, which include a weight coefficient vector, a learning rate, and termination condition parameters; Calculate the cost function value based on the aircraft attitude angle vector and the weight coefficient vector, , where the weight coefficient vector , the total force vector of the aircraft body axis , the total moment vector of the aircraft body axis ; Based on the aircraft attitude angle vector and the cost function value, perform gradient vector calculation to obtain the gradient value: ； ； ； Based on the current aircraft attitude angle vector , gradient vector , learning rate , iterate the state vector according to a preset threshold as the termination condition ; the preset threshold includes a cost function change threshold, a gradient threshold, and a maximum number of iterations; When the termination condition is satisfied, the optimized aircraft attitude angle vector is obtained and set to the flight simulator, and the total force and total moment of the aircraft body axis are zero, completing the ground trimming of the flight simulator.

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