An aircraft control surface limit cycle oscillation suppression method based on real-time inverse gap compensation

Abstract

The present application relates to aerospace control science and engineering technical field, concretely is a kind of aircraft control surface limit ring oscillation suppression method based on real-time inverse gap compensation, comprising the following steps: step S1, data collection and pretreatment;Step S2, gap detector solves real-time equivalent gap;Step S3, build real-time inverse gap module.The present application can directly detect actuator output point displacement, without detailed data of rudder position and real-time position error of rudder;The present application can not interfere with rudder system when no error occurs, thereby the ideal control state of rudder system can be guaranteed;The present application has low cost, and can be quickly promoted and used.

Description

Technical Field

[0001] This invention relates to the field of aerospace control science and engineering technology, specifically to a method for suppressing limit cycle oscillations of aircraft control surfaces based on real-time inverse clearance compensation. Background Technology

[0002] With the development of the aviation industry, the requirements for aircraft safety and the performance of flight control systems are becoming increasingly stringent. During flight, the control of control surfaces is crucial for maintaining aircraft stability and maneuverability. However, due to the complex dynamic characteristics of aircraft and interference from the external environment, aircraft control surfaces may exhibit limit cycle oscillations under specific operating conditions, which can threaten flight safety and passenger comfort.

[0003] Traditional methods for suppressing limit cycle oscillations in aircraft control surfaces caused by gaps mainly include techniques such as filtering, PID control, model reference adaptive control, and traditional inverse backlash compensation. However, these methods have some problems in practical applications. First, filtering methods process the input signal, which can suppress high-frequency oscillations, but introduces delays and reduces the response speed of the control system. Second, PID control methods need to be adjusted according to the real-time control surface position error, but due to the uncertainty of limit cycle oscillations, it is difficult to set the PID parameters to be at the optimal operating point. Model reference adaptive control methods establish a desired ideal model reference and compare the output of the actual system with the reference model. However, model reference adaptive control requires an accurate system model as a reference for error calculation and parameter adjustment. If the system model has errors or is not completely accurate, the controller performance may be affected. Traditional inverse backlash compensation methods have some drawbacks, including difficulty in parameter adjustment, dependence on the system model, high requirements for sensors, high computational resource requirements, and impact on system stability. Among these, traditional inverse backlash compensation has the best suppression effect, but in actual aircraft control surface systems, the gap value at the hole-shaft connection will continuously increase. As the gap value increases and changes, the inverse gap value of the inverse gap element will eventually be smaller than the gap value. At this point, the gap nonlinearity cannot be completely canceled out by the inverse gap element, and the system will exhibit gap nonlinearity again, resulting in limit cycle oscillations. Therefore, traditional methods have certain limitations in suppressing limit cycle oscillations. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a method for suppressing limit loop oscillations of aircraft control surfaces based on real-time inverse clearance compensation.

[0005] The technical problem to be solved by this invention is achieved by the following technical solution:

[0006] A method for suppressing limit cycle oscillations of aircraft control surfaces based on real-time inverse clearance compensation includes the following steps:

[0007] Step S1, Data Collection and Preprocessing:

[0008] The displacement data of the active and driven components at the mechanical connection of the aircraft control surface are collected in real time, and the displacement of the actuator output point and the deflection angle of the control surface are collected in real time. The control surface clearance is pre-processed through the mechanical structure at the connection between the actuator and the control surface.

[0009] Step S2: Solve for the real-time equivalent gap using a gap detector:

[0010] The real-time equivalent clearance is calculated by using the clearance input-output characteristics and the control surface deflection angle through a clearance detector.

[0011] Step S3: Build the real-time backlash module:

[0012] By using the output gap of the gap detector and the output point displacement of the actuator as input signals, a real-time inverse gap module is built and connected in series with the gap element, thereby eliminating gap characteristics and suppressing the limit cycle oscillation of the control surface.

[0013] Preferably, step S1 specifically includes:

[0014] Step S11, Data Collection:

[0015] Step S111: Collect the aircraft control surface deflection angle input voltage command signal, and use the maximum and minimum values ​​of the aircraft control surface deflection angle to fit the linear relationship between the aircraft control surface deflection angle and the input voltage command signal.

[0016] Step S112: Collect the displacement of the output point of the aircraft control surface actuator at the corresponding time, so as to obtain the relationship between the output point displacement and the input voltage command signal;

[0017] Step S113: Collect the voltage values ​​of the aircraft control surface angle-voltage sensor, and then fit the linear relationship of the angle voltage sensor by the maximum and minimum values ​​of the aircraft control surface deflection angle under steady state.

[0018] Step S12, Pre-treatment of rudder surface clearance:

[0019] Preprocessing data under specific conditions refers to measuring the actuator link length L and the height L1 of the attachment point relative to the connection point when the deflection angle is 0 (reaching a stable state).

[0020] Preferably, step S12 specifically includes:

[0021] A two-dimensional model of the control surface mechanical structure is performed: the control surface mounting point is fixed in the x and y directions. In the x-axis direction, assuming the control surface deflection angle is 0, the actuator connection point coordinates are (0,0), then the mounting point coordinates are (L,L1), where L is the actuator link length and L1 is the height of the mounting point relative to the connection point; when the control surface deflection angle is θ, the actuator connection point coordinates are (x...). e ,0), x e Since the output point displacement of the actuator is (L, L1), the coordinates of the attachment point remain (L, L1). Therefore, the geometric relationship along the x-axis is as follows:

[0022] L = x e +Lcosα-L1sinθ

[0023] In the formula, α is the angle between the actuator connecting rod and the x-axis.

[0024] Preferably, step S2 specifically includes:

[0025] Step S21: Use the input-output characteristic curve of the gap link to fit the wear gap at the mechanical connection of the aircraft control surface;

[0026] Step S22: Use the wear clearance obtained in step S21 and the actuator link length L and the height L1 of the attachment point relative to the connection point obtained in step S12 to solve for the real-time equivalent clearance value.

[0027] Preferably, step S21 specifically includes:

[0028] First, we can solve this problem using the gap input-output characteristics: Let d be the wear gap value, which is also the output of the gap detector; y(t) be the displacement of the driven component at the rudder surface connection; and x(t) be the displacement of the driving component at the rudder surface connection. Then we have:

[0029]

[0030] This allows us to obtain the real-time wear clearance.

[0031] Preferably, step S22 specifically includes:

[0032] The equivalent clearance is the component of the wear clearance at the included angle α, i.e., the real-time equivalent clearance d. e for:

[0033] d e =dcosα.

[0034] Preferably, step S3 specifically includes:

[0035] The real-time inverse gap module can be derived from the input-output characteristic equations:

[0036]

[0037] In the formula, d e The equivalent gap value fed back to the real-time inverse gap module by the gap detector, r(t-) is the input signal value of the real-time inverse gap module at the previous moment, and c(t-) is the output value of the real-time inverse gap module at the previous moment.

[0038] The beneficial effects of this invention are:

[0039] This invention can directly detect the displacement of the actuator output point without requiring detailed data on the rudder surface position and the real-time position error of the rudder surface.

[0040] The present invention can ensure that the control surface system will not be disturbed when no error occurs, thereby ensuring the ideal control state of the control surface system;

[0041] This invention has low cost and can be quickly promoted and used. Attached Figure Description

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0043] Figure 1 This is a flowchart from the present invention;

[0044] Figure 2 This is a structural block diagram of the present invention. Detailed Implementation

[0045] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0046] like Figures 1 to 2 As shown, a method for suppressing limit cycle oscillations of aircraft control surfaces based on real-time inverse clearance compensation includes the following steps:

[0047] Step S1, Data Collection and Preprocessing:

[0048] The displacement data of the driving and driven components at the mechanical connection of the aircraft control surface are collected in real time. The displacement data of the actuator output point and the control surface deflection angle are collected in real time. The control surface clearance is pre-processed through the mechanical structure at the actuator-control surface connection.

[0049] Step S1 specifically includes:

[0050] Step S11, Data Collection:

[0051] Step S111: Collect the aircraft control surface deflection angle input voltage command signal, and use the maximum and minimum values ​​of the aircraft control surface deflection angle to fit the linear relationship between the aircraft control surface deflection angle and the input voltage command signal.

[0052] Step S112: Collect the displacement of the output point of the aircraft control surface actuator at the corresponding time, so as to obtain the relationship between the output point displacement and the input voltage command signal;

[0053] Step S113: Collect the voltage values ​​of the aircraft control surface angle-voltage sensor, and then fit the linear relationship of the angle voltage sensor by the maximum and minimum values ​​of the aircraft control surface deflection angle under steady state.

[0054] Step S12, Pre-treatment of rudder surface clearance:

[0055] Data under specific conditions is preprocessed to determine the actuator linkage length L and the height L1 of the attachment point relative to the connection point.

[0056] Step S12 specifically includes:

[0057] To address the variation of equivalent clearance with the rudder surface deflection angle, a mathematical model is established for the mechanical connection of the rudder surface to solve the relationship between equivalent displacement and rudder surface deflection angle. A two-dimensional model of the rudder surface mechanical structure is performed: the rudder surface mounting point is fixed in the x and y directions. In the x-axis direction, when the rudder surface deflection angle is 0, the actuator connection point coordinates are (0,0), then the mounting point coordinates are (L,L1), where L is the actuator linkage length and L1 is the height of the mounting point relative to the connection point; when the rudder surface deflection angle is θ, the actuator connection point coordinates are (x,y). e ,0), x e Since the output point displacement of the actuator is (L, L1), the coordinates of the attachment point remain (L, L1). Therefore, the geometric relationship along the x-axis is as follows:

[0058] L = x e +Lcosα-L1sinθ

[0059] In the formula, α is the angle between the actuator connecting rod and the x-axis.

[0060] Step S2: Solve for the real-time equivalent gap using a gap detector:

[0061] The real-time equivalent clearance is calculated using a clearance detector that takes into account the clearance input-output characteristics and the control surface deflection angle. The clearance detector is primarily responsible for calculating the real-time equivalent clearance, which is often affected by two main factors: the wear clearance increases over time and the equivalent clearance changes with the control surface deflection angle.

[0062] Step S2 specifically includes:

[0063] Step S21: Use the input-output characteristic curve of the gap link to fit the wear gap at the mechanical connection of the aircraft control surface.

[0064] To address the issue of wear clearance increasing over time, we first utilize the clearance input-output characteristics: Let d be the wear clearance value, which is also the output of the clearance detector; y(t) be the displacement of the driven component at the rudder surface connection; and x(t) be the displacement of the driving component at the rudder surface connection. Then we have:

[0065]

[0066] This allows us to obtain the real-time wear clearance.

[0067] Step S22: Use the wear clearance obtained in step S21 and the actuator link length L and the height L1 of the attachment point relative to the connection point obtained in step S12 to solve for the real-time equivalent clearance value.

[0068] Step S22 specifically includes:

[0069] The equivalent clearance is the component of the wear clearance at the included angle α, i.e., the real-time equivalent clearance d. e for:

[0070] d e =dcosα.

[0071] Step S3: Build the real-time backlash module:

[0072] By using the output gap of the gap detector and the output point displacement of the actuator as input signals, a real-time inverse gap module is constructed and connected in series with the gap element to eliminate gap characteristics and suppress the limiting cycle oscillation of the control surface. The real-time inverse gap module has two inputs: an input signal and an equivalent gap value. The main function of the real-time inverse gap module is to ensure that the inverse gap value and the equivalent gap value are equal in real time, thereby eliminating gap characteristics.

[0073] The real-time inverse clearance module can transform a nonlinear element into a linear element based on the input signal and the equivalent clearance value obtained by the clearance detector. Similar to the mathematical concepts of function and inverse function, the clearance element and the real-time inverse clearance module can be compared to a "function" and an "inverse function," respectively. When these two are connected, they will form a linear element, which means that the real-time inverse clearance module can be used to counteract the influence of the clearance element on the aircraft control surface system.

[0074] Step S3 specifically includes:

[0075] The real-time inverse gap module can be derived from the input-output characteristic equations:

[0076]

[0077] In the formula, d eThe equivalent gap value fed back to the real-time inverse gap module by the gap detector, r(t-) is the input signal value of the real-time inverse gap module at the previous moment, and c(t-) is the output value of the real-time inverse gap module at the previous moment.

[0078] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely prisms of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for suppressing limit cycle oscillations of aircraft control surfaces based on real-time inverse clearance compensation, characterized in that: Includes the following steps: Step S1, Data Collection and Preprocessing: The displacement data of the active and driven components at the mechanical connection of the aircraft control surface are collected in real time, and the displacement of the actuator output point and the deflection angle of the control surface are collected in real time. The control surface clearance is pre-processed through the mechanical structure at the connection between the actuator and the control surface. Step S2: Solve for the real-time equivalent gap using a gap detector: The real-time equivalent clearance is calculated by using the clearance input-output characteristics and the control surface deflection angle through a clearance detector. Step S2 specifically includes: Step S21: Use the input-output characteristic curve of the gap link to fit the wear gap at the mechanical connection of the aircraft control surface; Step S21 specifically includes: First, we can solve this problem using the gap input / output characteristics: Let... This is the wear gap value, which is also the output of the gap detector. This refers to the displacement of the driven component at the rudder surface connection. For the displacement of the driving component at the rudder surface connection, we have: ； Thus, the real-time wear clearance can be obtained; Step S22: Utilize the wear clearance and actuator link length obtained in step S21 and the height of the hanging point relative to the connection point To solve for the real-time equivalent gap value; Step S22 specifically includes: The equivalent clearance is the wear clearance at the included angle. The component below, i.e., the real-time equivalent gap for: ； Step S3: Build the real-time backlash module: By using the output gap of the gap detector and the output point displacement of the actuator as input signals, a real-time inverse gap module is built and connected in series with the gap element, thereby eliminating gap characteristics and suppressing the limit cycle oscillation of the control surface.

2. The method for suppressing limit cycle oscillations of aircraft control surfaces based on real-time inverse clearance compensation according to claim 1, characterized in that: Step S1 specifically includes: Step S11, Data Collection: Step S111: Collect the aircraft control surface deflection angle input voltage command signal, and use the maximum and minimum values ​​of the aircraft control surface deflection angle to fit the linear relationship between the aircraft control surface deflection angle and the input voltage command signal. Step S112: Collect the displacement of the output point of the aircraft control surface actuator at the corresponding time, so as to obtain the relationship between the output point displacement and the input voltage command signal; Step S113: Collect the voltage values ​​of the aircraft control surface angle-voltage sensor, and then fit the linear relationship of the angle voltage sensor by the maximum and minimum values ​​of the aircraft control surface deflection angle under steady state. Step S12, Pre-treatment of rudder surface clearance: Preprocess the data under specific conditions to determine the length of the actuator link. and the height of the hanging point relative to the connection point .

3. The method for suppressing limit cycle oscillations of aircraft control surfaces based on real-time inverse clearance compensation according to claim 2, characterized in that: Step S12 specifically includes: Two-dimensional modeling of the control surface mechanical structure: control surface mounting points at... The direction remains fixed, in In the axial direction, let the deflection angle of the rudder surface be... At that time, the coordinates of the actuator connection point are The coordinates of the hanging point are ,in The length of the actuator link. The height of the mounting point relative to the connection point; when the rudder surface deflection angle is... At that time, the coordinates of the actuator connection point are , The displacement of the actuator output point, the coordinates of the hanging point are still [missing information]. ,so, The geometric relationships along the axial direction are as follows: ； In the formula, Actuator linkage and The included angle of the axis.

4. The method for suppressing limit cycle oscillations of aircraft control surfaces based on real-time inverse clearance compensation according to claim 1, characterized in that: Step S3 specifically includes: The real-time inverse gap module can be derived from the input-output characteristic equations: ； In the formula, The equivalent gap value fed back to the real-time inverse gap circuit by the gap detector. This is the input signal value of the real-time inverse gap module at the previous moment. This is the output value of the real-time reverse gap module at the previous moment.

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