Digital method for calculating side slip of a ball

Abstract

The application provides a digital side-slip ball calculation method, and solves the problem of low accuracy of a current side-slip instrument in reflecting the side-slip condition of an aircraft, and comprises the following steps: step one, obtaining flight state information and flight parameter information of the aircraft; step two, obtaining parameter information of the digital side-slip ball; and step three, judging whether the aircraft is in steady flight or dynamic flight according to the flight state information, and selecting different parameter information to calculate corresponding digital side-slip angles in different stages through a dynamic equation of the digital side-slip ball under different flight states. The application establishes the dynamic equation of the digital side-slip ball under different flight states of the aircraft corresponding to the mechanical side-slip ball, calculates the digital side-slip angle corresponding to different flight states of the aircraft, and the calculated digital side-slip angle is basically consistent with the side-slip angle of the aircraft. The digital side-slip ball calculation of the application meets the accuracy requirement of the side-slip condition of the aircraft.

Description

Technical Field

[0001] This invention belongs to the field of strapdown inertial navigation technology, specifically relating to a digital method for calculating the side-slip ball. Background Technology

[0002] The digital cockpit of modern aircraft is a crucial part of the aviation industry's digital transformation, integrating advanced technologies such as human-machine interaction, control systems, and data analytics to provide passengers and crew with a safer, more convenient, and more comfortable aviation experience. Through advanced control systems, crew and passengers can freely adjust the angle, position, and firmness of their seats, as well as temperature and lighting effects, for a more comfortable experience. Furthermore, in emergencies, the digital cockpit of modern aircraft can provide critical information and operational guidance, ensuring the safety of passengers and crew.

[0003] Strapdown inertial navigation systems (SINS) are important airborne navigation devices with advantages such as high navigation accuracy, and are widely used in both military and civilian fields. SINS devices use inertial measurement elements such as gyroscopes and accelerometers, which are directly mounted on the airborne carrier. A computer transforms and calculates the measured signals to obtain navigation parameters such as attitude, velocity, and heading, providing real-time navigation information such as the aircraft's position, velocity, and attitude. They do not rely on external information and do not radiate energy to the outside world, offering advantages such as good concealment and resistance to interference and damage.

[0004] Sideslip detectors, another important airborne navigation device, are used to indicate the degree and direction of an aircraft's sideslip. A sideslip ball, a sensitive element of the detector, remains stationary between two lines in the center of a glass tube when the aircraft (such as an airplane) is flying straight, due to gravity. If the aircraft turns without sideslip, the ball will remain in the center of the tube. However, if an incorrect turn results in sideslip, a lateral force will be generated, causing the ball to roll towards one end of the tube. By observing the distance and direction the ball deviates from the center of the tube, the degree and direction of the aircraft's sideslip can be determined.

[0005] To prevent the sideslip ball from cracking under high stress, patent publication CN216581053U discloses a novel sideslip device. This device includes a curved glass tube and two sets of baffles symmetrically arranged within the tube. Each baffle has a through-hole at its center. The ends of the glass tube are sealed, forming an air chamber between the baffles and the ends of the glass tube. A working chamber is formed between the two sets of baffles and the glass tube. A ball bearing rolls within the working chamber. The glass tube is filled with damping fluid and air. The damping fluid must overflow the through-hole on the baffle to seal the air within the air chamber. The air filling the glass tube utilizes the compressibility of air to eliminate or reduce the pressure exerted on the glass tube by the damping fluid during high-temperature expansion.

[0006] While the aforementioned patent documents effectively prevent the sideslip ball from shattering, there is still a discrepancy between the sideslip condition reflected by the sideslip ball and the actual situation, making it impossible to accurately reflect the aircraft's sideslip status. Therefore, improving the sideslip data of the sideslip meter, and thus providing accurate aircraft sideslip data for modern aircraft digital cockpits, has become extremely necessary. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing sideslip meters in terms of low accuracy in reflecting aircraft sideslip conditions. This invention provides a digital sideslip ball calculation method that establishes digital sideslip ball dynamic equations for different flight states of the aircraft, corresponding to mechanical sideslip balls. It also calculates digital sideslip angles for different flight states, and the calculated digital sideslip angles are essentially consistent with the aircraft's sideslip angles. Therefore, the digital sideslip ball calculation method of this invention meets the accuracy requirements for aircraft sideslip conditions.

[0008] To achieve the above objectives, the technical solution provided by this invention is:

[0009] A digital method for calculating the movement of a side-slipping ball includes the following steps:

[0010] Step 1: Obtain the flight status information and flight parameter information of the aircraft. The flight status information includes steady-state flight and dynamic flight, and the flight parameter information includes the aircraft lift, aircraft mass, and aircraft side force.

[0011] Step 2: Obtain the parameter information of the digital side-sliding ball, wherein the parameter information includes the ball mass, the bending radius of the bend, the ball displacement, and the ball angular velocity;

[0012] Step 3: Based on the flight status information, determine in real time whether the aircraft is in steady-state flight or dynamic flight. Different parameters are selected for different flight states, and the digital sideslip angle corresponding to different stages is calculated using the dynamic equations of the digital sideslip ball. Specifically:

[0013] If the aircraft is in steady-state flight, the digital sideslip angle in the steady-state stage is calculated based on the aircraft lift and side force obtained in real time in step one, as well as the dynamic equation of the digital sideslip ball.

[0014] If the aircraft is in dynamic flight, the digital sideslip angle for the dynamic stage is calculated based on the flight parameter information obtained in real time in step one, the parameter information obtained in real time in step two, and the dynamic equation of the digital sideslip ball.

[0015] As a further limitation of the present invention, in step one:

[0016] The flight status information and flight parameter information of the aircraft are obtained by calculation using an inertial navigation device; the inertial navigation device is installed on the airborne body of the aircraft.

[0017] As a further limitation of the present invention, in step two:

[0018] The ball's displacement includes its x-axis displacement, y-axis displacement, and z-axis displacement. The ball's angular velocity includes its angular velocity ω along the x-axis. x The angular velocity ω of the ball along the y-axis y The angular velocity ω of the ball along the z-axis z ;

[0019] In step two:

[0020] The parameters of the digital sideslip ball are obtained through calculations using an inertial navigation system. Specifically, the inertial navigation system calculates the damping ratio ζ of the sideslip ball under liquid damping within the glass tube, the bending radius R of the sidelip ball's bend, and the magnification X displayed by the sideslip ball. The expression for calculating the damping ratio ζ is as follows:

[0021]

[0022] In the formula, c represents the damping coefficient, and m B The mass of the sliding ball is represented by R, the bending radius of the sliding ball's bend is represented by F. Z Let m represent the lift of the aircraft, m represent the mass of the aircraft, x represent the displacement of the ball along the x-axis, and ω represent the displacement of the ball along the x-axis. x ω represents the angular velocity of the ball along the x-axis. z This represents the angular velocity of the ball along the z-axis. Let represent the second derivative of the displacement of the ball along the z-direction. This represents the first derivative of the displacement of the ball along the y-axis.

[0023] As a further limitation of the present invention, the inertial navigation device also calculates the aircraft sideslip angle β, and the calculation formula is as follows:

[0024]

[0025] In the formula, v x v represents the x-axis airspeed component of the aircraft in the body coordinate system. y v represents the y-axis airspeed component of the aircraft in the body coordinate system. z This represents the z-axis airspeed component of the aircraft in the body coordinate system.

[0026] The aircraft sideslip angle β is verified by the digital sideslip angle described in step three.

[0027] As a further limitation of the present invention, in step three:

[0028] (1) The dynamic equation of the digital sideslip ball during steady-state flight is expressed as:

[0029]

[0030] In the formula, γ B F represents the digital sideslip angle. Y F represents the lateral force of the aircraft. Z Indicates the lift of an aircraft;

[0031] (2) The dynamic equation of the digital sideslip ball during dynamic flight is expressed as:

[0032]

[0033] In the formula, Let m represent the second derivative of the sideslip angle, c represent the damping coefficient, and m represent the second derivative of the sideslip angle. B This indicates the mass of the ball used for the side-sliding motion. Let R represent the first derivative of the sideslip angle, R represent the bending radius of the sideslip ball bend, and m represent the mass of the aircraft. ω represents the second differential of the displacement of the ball along the z-axis. x This represents the angular velocity of the ball along the x-axis. Let represent the first derivative of the displacement of the ball along the y-axis. ω represents the second derivative of the displacement of the ball along the y-axis. y This represents the angular velocity of the ball along the y-axis. This represents the first derivative of the displacement of the ball along the z-direction.

[0034] As a further limitation of the present invention, step three also includes:

[0035] When calculating the digital sideslip angle in the dynamic phase, the x-direction displacement of the ball along the x-axis, the y-direction displacement of the ball along the y-axis, and the z-direction displacement of the ball along the z-axis are all calculated based on the motion state of the aircraft and the installation position of the sideslip ball on the aircraft. In the steady-state flight state, the ball has no relative motion with the aircraft, while in the dynamic flight state, the ball moves relative to the aircraft.

[0036] When calculating the digital sideslip angle during the dynamic phase, the angular velocity ω of the ball along the x-axis is... x The angular velocity ω of the ball along the y-axis y The angular velocity ω of the ball along the z-axis z All were obtained through calculations using inertial navigation equipment;

[0037] When calculating the digital sideslip angle in the dynamic phase, the damping coefficient c is considered in relation to the damping ratio ζ of the sideslipping ball being damped by the liquid within the glass tube, and the mass m of the sideslipping ball is also considered.B The bending radius R of the side-slip ball bend, and the lift F of the aircraft. Z The mass of the aircraft is m, the displacement of the ball along the x-axis is x, and the angular velocity of the ball along the x-axis is ω. x The angular velocity ω of the ball along the z-axis z The displacements of the ball along the y-direction (y) and the displacements along the z-direction (z) are calculated.

[0038] The advantages of this invention are:

[0039] This invention establishes digital sideslip ball dynamic equations for aircraft under different flight states corresponding to mechanical sideslip balls, and calculates digital sideslip angles for different flight states. The calculated digital sideslip angles are basically consistent with the aircraft sideslip angles. The digital sideslip ball calculation of this invention meets the accuracy requirements for aircraft sideslip conditions.

[0040] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0041] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0042] Figure 1 The present invention provides a flowchart of a digital side-slip ball calculation method;

[0043] Figure 2 The diagram illustrating the relationship between the airflow coordinate system and the body coordinate system provided by this invention;

[0044] Figure 3 : Schematic diagram of a steady-state flight sideslip ball provided by this invention;

[0045] Figure 4 : A schematic diagram of a dynamic flying sideslip ball provided by this invention;

[0046] Figure 5 Simulation diagram of the sideslip angle calculated by the digital sideslip ball calculation method provided by this invention. Detailed Implementation

[0047] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0048] Please see Figure 1 This invention discloses a digital method for calculating the sideslip of a ball, comprising the following steps:

[0049] Step 1: Obtain the flight status information and flight parameter information of the aircraft. The flight status information includes steady-state flight and dynamic flight, and the flight parameter information includes the aircraft lift, aircraft mass, and aircraft lateral force.

[0050] Specifically, in step one of the embodiments of the present invention: the flight status information and flight parameter information of the aircraft are obtained by calculation through the inertial navigation device; the inertial navigation device is installed on the airborne body of the aircraft.

[0051] Step 2: Obtain the parameter information of the digital side-sliding ball, including the ball mass, bending radius of the bend, ball displacement, and ball angular velocity.

[0052] Specifically, in step two of this embodiment of the invention: the displacement of the small ball includes the x-direction displacement of the small ball along the x-axis, the y-direction displacement of the small ball along the y-axis, and the z-direction displacement of the small ball along the z-axis; the angular velocity of the small ball includes the angular velocity ω of the small ball along the x-axis. x The angular velocity ω of the ball along the y-axis y The angular velocity ω of the ball along the z-axis z .

[0053] Specifically, in step two of this embodiment of the invention: the parameter information of the digital side-slip ball is obtained by calculation using an inertial navigation device; specifically, the inertial navigation device calculates the damping ratio ζ of the side-slip ball being damped by the liquid inside the glass tube, the bending radius R of the side-slip ball's curved tube, and the magnification X displayed by the side-slip ball; wherein, the expression for calculating the damping ratio ζ is:

[0054]

[0055] In formula (1), c represents the damping coefficient, and m B The mass of the sliding ball is represented by R, the bending radius of the sliding ball's bend is represented by F. Z Let m represent the lift of the aircraft, m represent the mass of the aircraft, x represent the displacement of the ball along the x-axis, and ω represent the displacement of the ball along the x-axis. x ω represents the angular velocity of the ball along the x-axis. z This represents the angular velocity of the ball along the z-axis. Let represent the second derivative of the displacement of the ball along the z-direction. This represents the first derivative of the displacement of the ball along the y-axis.

[0056] Step 3: Based on flight status information, determine in real time whether the aircraft is in steady-state or dynamic flight. Different parameters are selected for different flight states, and the digital sideslip angle corresponding to different stages is calculated using the dynamic equations of the digital sideslip ball. Specifically:

[0057] If the aircraft is in steady-state flight, the digital sideslip angle in the steady-state stage is calculated based on the aircraft lift and side force obtained in real time in step one, as well as the dynamic equation of the digital sideslip ball.

[0058] If the aircraft is in dynamic flight, the digital sideslip angle for the dynamic stage is calculated based on the flight parameter information obtained in real time in step one, the parameter information obtained in real time in step two, and the dynamic equation of the digital sideslip ball.

[0059] Specifically, in step three of the embodiments of the present invention:

[0060] (1) The dynamic equation of the digital sideslip ball during steady-state flight is expressed as:

[0061]

[0062] In formula (2), γ B F represents the digital sideslip angle. Y F represents the lateral force of the aircraft. Z It represents the lift of an aircraft.

[0063] Specifically, the process of obtaining the above formula (2) in this embodiment of the invention is as follows:

[0064] Please see Figure 3 During steady-state flight, the angle γ displayed by the sideslip instrument B It satisfies formula (3), which can be expressed as:

[0065]

[0066] In formula (3), γ B The sideslip angle is represented by a number, m represents the aircraft mass, and a represents the weight of the aircraft. Oy Indicates y b Zero-biased acceleration in the direction, a Oz Indicate z b Zero-biased acceleration in the direction, ω x ω represents the angular velocity of the ball along the x-axis. y ω represents the angular velocity of the ball along the y-axis. z F represents the angular velocity of the ball along the z-axis. Z F represents the lift of an aircraft. Y This indicates the lateral force on the aircraft.

[0067] In this embodiment of the invention, if the sideslip ball is pre-positioned at the center of mass of the aircraft, then x = 0, and formula (3) degenerates into:

[0068]

[0069] In formula (4), γ B F represents the digital sideslip angle.Y F represents the lateral force of the aircraft. Z It represents the lift of an aircraft.

[0070] Due to the digital sideslip angle γ B The angle is usually small, so formula (4) can be further simplified to formula (2).

[0071] (2) The dynamic equation of the digital sideslip ball during dynamic flight is expressed as:

[0072]

[0073] In formula (5), Let m represent the second derivative of the sideslip angle, c represent the damping coefficient, and m represent the second derivative of the sideslip angle. B This indicates the mass of the ball used for the side-sliding motion. Let R represent the first derivative of the sideslip angle, R represent the bending radius of the sideslip ball bend, and m represent the mass of the aircraft. ω represents the second differential of the displacement of the ball along the z-axis. x This represents the angular velocity of the ball along the x-axis. Let represent the first derivative of the displacement of the ball along the y-axis. ω represents the second derivative of the displacement of the ball along the y-axis. y This represents the angular velocity of the ball along the y-axis. This represents the first derivative of the displacement of the ball along the z-direction.

[0074] Specifically, the process of obtaining the above formula (5) in this embodiment of the invention is as follows:

[0075] During dynamic flight, the sideslip ball and the aircraft are in relative motion. The acceleration of the sideslip ball includes entrainment acceleration, relative acceleration, and Coriolis acceleration, expressed as:

[0076]

[0077] In formula (6), This indicates the position of the side-sliding ball at point B in the y-axis. b Directional correction acceleration, a Oy Indicates y b Zero-biased acceleration in the direction, where x represents the displacement of the ball along the x-direction, ω x ω represents the angular velocity of the ball along the x-axis. y This represents the angular velocity of the ball along the y-axis. Let represent the second derivative of the displacement of the ball along the y-axis. This indicates the side-sliding ball at point B in the z-axis. b Directional correction acceleration, Let represent the first derivative of the displacement of the ball along the z-axis. ω represents the first differential of the displacement of the ball along the z-axis.z This represents the angular velocity of the ball along the z-axis. This represents the first derivative of the displacement of the ball along the y-axis.

[0078] Let F be the damping force of the liquid inside the glass tube. c It is obtained through the following formula (7), the expression of which is:

[0079]

[0080] In formula (7), v r The value represents the relative velocity, c represents the damping coefficient, and R represents the bending radius of the mechanically oriented side-slip ball bend. This represents the first derivative of the sideslip angle.

[0081] Please see Figure 4 The sliding ball is subjected to the z-axis lift component, the y-axis lateral force component, and the acceleration and damping force of the sliding ball relative to the glass tube in the direction parallel to the glass tube. The force balance equation of the sliding ball in the glass tube includes the following formula (8):

[0082]

[0083] In formula (8), m B This indicates the mass of the ball used for the side-sliding motion. This indicates the side-sliding ball at point B in the z-axis. b Directional correction acceleration, γ B Indicates the digital sideslip angle. This indicates the position of the side-sliding ball at point B in the y-axis. b The directional correction acceleration, where R represents the bending radius of the mechanically oriented side-slip ball bend. F represents the second derivative of the digital sideslip angle. c This represents the damping force of the liquid inside the glass tube.

[0084] Due to the digital sideslip angle γ B For small angles, and sinγ B ≈γ B cosγ B ≈1, Substituting formula (7) into formula (8), the force equilibrium equation can be transformed into:

[0085]

[0086] In formula (9), m B R represents the mass of the sliding ball, and R represents the bending radius of the mechanical sliding ball bend. Let represent the second derivative of the digital sideslip angle, 'c' represent the damping coefficient, and 'R' represent the bending radius of the mechanical sideslip ball bend. Represent the first derivative of the sideslip angle. This indicates the side-sliding ball at point B in the z-axis. b Directional correction acceleration, γ B Indicates the digital sideslip angle. This indicates the position of the side-sliding ball at point B in the y-axis. b Directional correction acceleration.

[0087] Divide both sides of formula (9) by m. B R, normalizing the coefficients of the quadratic term, yields formula (10), which is expressed as:

[0088]

[0089] In formula (10), Let ζ represent the second derivative of the digital sideslip angle, ζ represent the damping ratio of the sideslipping ball within the glass tube due to liquid damping, and ω0 represent the natural frequency. Let γ be the first derivative of the sideslip angle. B denoted by , and f represents the control quantity output externally.

[0090] In formula (10), the expression for the natural frequency ω0 is:

[0091]

[0092] In formula (11), R represents the bending radius of the side-slip ball bend, and F Z Let m represent the lift of the aircraft, x represent the mass of the aircraft, and ω represent the displacement of the ball along the x-axis. x ω represents the angular velocity of the ball along the x-axis. z This represents the angular velocity of the ball along the z-axis. Let represent the first derivative of the displacement of the ball along the z-axis. This represents the first derivative of the displacement of the ball along the y-axis.

[0093] In formula (10), the expression for the externally output control quantity f is:

[0094]

[0095] In formula (12), R represents the bending radius of the side-slip ball bend, and F Y Let m represent the lateral force on the aircraft, x represent the mass of the aircraft, and ω represent the displacement of the ball along the x-axis. x ω represents the angular velocity of the ball along the x-axis. y This represents the angular velocity of the ball along the y-axis. ω represents the second derivative of the displacement of the ball along the y-axis. y This represents the angular velocity of the ball along the y-axis. This represents the first derivative of the displacement of the ball along the z-direction.

[0096] If the sideslipping ball is pre-positioned at the center of mass of the aircraft, then the ball's displacement along the x-direction is x = 0, and formula (11) degenerates into:

[0097]

[0098] In formula (13), R represents the bending radius of the side-slip ball bend, and F Z This represents the lift of the aircraft, and m represents the mass of the aircraft. ω represents the first differential of the displacement of the ball along the z-axis. x This represents the angular velocity of the ball along the x-axis. This represents the first derivative of the displacement of the ball along the y-axis.

[0099] Formula (1) then degenerates into:

[0100]

[0101] In formula (14), c represents the damping coefficient, m B The mass of the sliding ball is represented by R, the bending radius of the sliding ball's bend is represented by F. Z The value m represents the lift of the aircraft, and m represents the mass of the aircraft. ω represents the second differential of the displacement of the ball along the z-axis. x This represents the angular velocity of the ball along the x-axis. This represents the first derivative of the displacement of the ball along the y-axis.

[0102] Formula (12) then degenerates into:

[0103]

[0104] In formula (15), R represents the bending radius of the side-slip ball bend, and F Y This represents the lateral force on the aircraft, where m represents the aircraft's mass. ω represents the second derivative of the displacement of the ball along the y-axis. y This represents the angular velocity of the ball along the y-axis. This represents the first derivative of the displacement of the ball along the z-direction.

[0105] Substituting equations (13), (14), and (15) into equation (10), the dynamic equation of the digital sideslip ball during dynamic flight is simplified to equation (5).

[0106] Furthermore, in this embodiment of the invention, the inertial navigation device also calculates the aircraft sideslip angle β, and verifies the digital sideslip angle in step three above using the aircraft sideslip angle β.

[0107] The formula for calculating the aircraft sideslip angle β is:

[0108]

[0109] In formula (16), v x v represents the x-axis airspeed component of the aircraft in the body coordinate system. y v represents the y-axis airspeed component of the aircraft in the body coordinate system. z This represents the z-axis airspeed component of the aircraft in the body coordinate system.

[0110] Please see Figure 2 , Figure 2 This is a diagram showing the relationship between the aircraft's airflow coordinate system and its body coordinate system. Figure 2 Ox b y b z b For the body coordinate system, Ox a y a z a Let x be the airflow coordinate system. a For the direction of the flight trajectory, Figure 2 β represents the aircraft's sideslip angle β. Please refer to [link / reference]. Figure 3 Traditional airborne equipment adopts Figure 3 The small ball shown slides left and right inside the glass tube after being damped by liquid, representing the sideslip angle. The motion characteristics of the sideslipping ball are related to the aircraft's sideslip angle, the liquid damping inside the glass tube, and the bending radius R of the glass tube.

[0111] Please continue reading. Figure 2 In this embodiment of the invention, a side-sliding ball is pre-installed at x b Point B on the axis corresponds to the coordinates (x, 0, 0) of the sliding ball in the body coordinate system. In steady state, the sliding ball has no relative motion to the body. b With its direction constrained, the acceleration experienced by the sideslipping ball in steady state includes zero-bias acceleration 'a'. O And the acceleration generated by the rotation of the lever arm x of the machine, in the machine coordinate system y b ,z b The acceleration in the direction is:

[0112]

[0113] In formula (17), a By This indicates the position of the side-sliding ball at point B in the y-axis. b acceleration in the direction, a Oy Indicates y b Zero-biased acceleration in the direction, where x represents the displacement of the ball along the x-direction, ω x ω represents the angular velocity of the ball along the x-axis. y Let a represent the angular velocity of the ball along the y-axis. Bz This indicates the side-sliding ball at point B in the z-axis. bacceleration in the direction, a Oz Indicate z b Zero-biased acceleration in the direction, ω z This represents the angular velocity of the ball along the z-axis.

[0114] Furthermore, step three of the embodiments of the present invention also includes:

[0115] When calculating the digital sideslip angle in the dynamic phase, the x-direction displacement of the ball along the x-axis, the y-direction displacement of the ball along the y-axis, and the z-direction displacement of the ball along the z-axis are all calculated based on the motion state of the aircraft and the installation position of the sideslip ball on the aircraft. In the steady-state flight state, the ball has no relative motion with the aircraft, while in the dynamic flight state, the ball moves relative to the aircraft.

[0116] When calculating the digital sideslip angle during the dynamic phase, the angular velocity ω of the ball along the x-axis is... x The angular velocity ω of the ball along the y-axis y The angular velocity ω of the ball along the z-axis z All were obtained through calculations using inertial navigation equipment;

[0117] When calculating the digital sideslip angle in the dynamic phase, the damping coefficient c is considered in relation to the damping ratio ζ of the sideslipping ball being damped by the liquid within the glass tube, and the mass m of the sideslipping ball is also considered. B The bending radius R of the side-slip ball bend, and the lift F of the aircraft. Z The mass of the aircraft is m, the displacement of the ball along the x-axis is x, and the angular velocity of the ball along the x-axis is ω. x The angular velocity ω of the ball along the z-axis z The displacements of the ball along the y-direction (y) and the displacements along the z-direction (z) are calculated.

[0118] A digital side-slip ball calculation method according to an embodiment of the present invention, through iterative verification, simulation results are as follows: Figure 5 , Figure 5 The red line represents the mechanical sideslip angle, and the blue line represents the digital sideslip angle. The two are essentially consistent, realizing a digital sideslip ball. This embodiment of the invention establishes the dynamic equations of the digital sideslip ball using the inertial parameters in the above formulas. The calculated digital sideslip angle is essentially consistent with the aircraft's sideslip angle, proving that the digital sideslip ball calculation in this embodiment of the invention meets the accuracy requirements for aircraft sideslip conditions.

[0119] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. A digital method for calculating the movement of a side-slipping ball, characterized in that, Includes the following steps: Step 1: Obtain the flight status information and flight parameter information of the aircraft. The flight status information includes steady-state flight and dynamic flight, and the flight parameter information includes the aircraft lift, aircraft mass, and aircraft side force. Step 2: Obtain the parameter information of the digital side-sliding ball, wherein the parameter information includes the ball mass, the bending radius of the bend, the ball displacement, and the ball angular velocity; Step 3: Based on the flight status information, determine in real time whether the aircraft is in steady-state flight or dynamic flight. Different parameters are selected for different flight states, and the digital sideslip angle corresponding to different stages is calculated using the dynamic equations of the digital sideslip ball. Specifically: If the aircraft is in steady-state flight, the digital sideslip angle in the steady-state stage is calculated based on the aircraft lift and side force obtained in real time in step one, as well as the dynamic equation of the digital sideslip ball. If the aircraft is in dynamic flight, the digital sideslip angle for the dynamic phase is calculated based on the flight parameter information obtained in real time in step one, the parameter information obtained in real time in step two, and the dynamic equation of the digital sideslip ball; in step three: (1) The dynamic equation of the digital sideslip ball during steady-state flight is expressed as: In the formula, γ B F represents the digital sideslip angle. Y F represents the lateral force of the aircraft. Z Indicates the lift of an aircraft; (2) The dynamic equation of the digital sideslip ball during dynamic flight is expressed as: In the formula, Let m represent the second derivative of the sideslip angle, c represent the damping coefficient, and m represent the second derivative of the sideslip angle. B This indicates the mass of the ball used for the side-sliding motion. Let R represent the first derivative of the sideslip angle, R represent the bending radius of the sideslip ball bend, and m represent the mass of the aircraft. ω represents the second differential of the displacement of the ball along the z-axis. x This represents the angular velocity of the ball along the x-axis. Let represent the first derivative of the displacement of the ball along the y-axis. ω represents the second derivative of the displacement of the ball along the y-axis. y This represents the angular velocity of the ball along the y-axis. This represents the first derivative of the displacement of the ball along the z-direction.

2. The digital side-slip ball calculation method according to claim 1, characterized in that, In step one: The flight status information and flight parameter information of the aircraft are obtained by calculation using an inertial navigation device; the inertial navigation device is installed on the airborne body of the aircraft.

3. The digital side-slip ball calculation method according to claim 1, characterized in that, In step two: The ball's displacement includes its x-axis displacement, y-axis displacement, and z-axis displacement. The ball's angular velocity includes its angular velocity ω along the x-axis. x The angular velocity ω of the ball along the y-axis y The angular velocity ω of the ball along the z-axis z ; In step two: The parameters of the digital sideslip ball are obtained through calculations using an inertial navigation system; specifically, the inertial navigation system calculates the damping ratio of the sideslip ball under liquid damping within the glass tube. The bending radius R of the side-slip ball bend, and the magnification X displayed by the side-slip ball; where, the damping ratio... The calculation expression is: In the formula, c represents the damping coefficient, and m B The mass of the sliding ball is represented by R, the bending radius of the sliding ball's bend is represented by F. Z Let m represent the lift of the aircraft, m represent the mass of the aircraft, x represent the displacement of the ball along the x-axis, and ω represent the displacement of the ball along the x-axis. x ω represents the angular velocity of the ball along the x-axis. z This represents the angular velocity of the ball along the z-axis. Let represent the second derivative of the displacement of the ball along the z-direction. This represents the first derivative of the displacement of the ball along the y-axis.

4. A digital side-slip ball calculation method according to claim 2 or 3, characterized in that, The inertial navigation equipment also calculates the aircraft's sideslip angle β, using the following formula: In the formula, v x v represents the x-axis airspeed component of the aircraft in the body coordinate system. y v represents the y-axis airspeed component of the aircraft in the body coordinate system. z This represents the z-axis airspeed component of the aircraft in the body coordinate system. The aircraft sideslip angle β is verified by the digital sideslip angle described in step three.

5. The digital side-slip ball calculation method according to claim 1, characterized in that, Step three further includes: when calculating the digital sideslip angle in the dynamic phase, the x-direction displacement of the ball along the a-axis, the y-direction displacement of the ball along the y-axis, and the z-direction displacement of the ball along the z-axis are all calculated based on the motion state of the aircraft and the installation position of the sideslipping ball on the aircraft. Specifically, when the aircraft is in a steady-state flight state, there is no relative motion between the ball and the aircraft; when the aircraft is in a dynamic flight state, there is relative motion between the ball and the aircraft. When calculating the digital sideslip angle in the dynamic phase, the angular velocity ω of the ball along the x-axis... x The angular velocity ω of the ball along the y-axis y The angular velocity ω of the ball along the z-axis z All were obtained through calculations using inertial navigation equipment; When calculating the digital sideslip angle during the dynamic phase, the damping coefficient c is the damping ratio of the sideslip ball being damped by the liquid within the glass tube. The mass m of the side-sliding ball B The bending radius R of the side-slip ball bend, and the lift F of the aircraft. Z The mass of the aircraft is m, the displacement of the ball along the x-axis is x, and the angular velocity of the ball along the x-axis is ω. x The angular velocity ω of the ball along the z-axis z The displacements of the ball along the y-direction (y) and the displacements along the z-direction (z) are calculated.

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