A method for airflow angle voting based on analytical margin
By combining the analytical redundancy method with aerodynamic data and acceleration sensors to calculate the analytical airflow angle, and using triple redundancy signal comparison, the problem of signal deviation of airflow angle sensor in aircraft is solved, thereby improving the accuracy of airflow angle measurement and system reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIANGXI HONGDU AVIATION IND GRP
- Filing Date
- 2026-03-17
- Publication Date
- 2026-07-03
AI Technical Summary
In an aircraft, when the output signals of two sets of airflow angle sensors are out of tolerance, it is impossible to determine which set of signals is correct, resulting in the inability to confirm the true value and affecting flight safety.
The analytical redundancy method is adopted, which uses the aircraft's aerodynamic data and airborne acceleration sensor to calculate the analytical airflow angle, and selects the correct airflow angle signal by comparing the three redundancy signals and combining the "three-judgment-two" logic.
This improves the accuracy of airflow angle measurement and the reliability of the system, ensuring flight safety.
Smart Images
Figure CN122330461A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of aircraft control system technology, specifically relating to a flow angle voting method based on analytical redundancy. Background Technology
[0002] In aircraft, airflow angles (including angle of attack and sideslip angle) are key parameters describing the relationship between airflow and the aircraft's direction of motion, playing a decisive role in the aircraft's aerodynamic performance, stability, and handling. Modern aircraft strive for higher speeds, greater fuel efficiency, and enhanced maneuverability, often operating in a longitudinally and directionally statically unstable state. For such high-performance aircraft, effective monitoring of airflow angles is directly related to flight safety.
[0003] To improve the accuracy and safety of airflow angle measurement, and considering the symmetry of the aircraft and the characteristics of the airflow field, high-performance aircraft are generally equipped with two sets of airflow angle sensors. Taking into account the airflow direction of the fuselage, the sensors are distributed on both sides of the fuselage or nose, forming a dual-redundant sensor design. When both sets of sensors are working normally, the correct airflow angle value can be obtained by averaging the values.
[0004] When two sets of sensor output signals exceed the tolerance, it becomes impossible to determine which set of sensor signals is correct. To address this issue, it is necessary to propose an airflow angle voting method based on analytical redundancy. Summary of the Invention
[0005] Purpose of the invention: To address the problem that the true value cannot be confirmed when the dual-redundant airflow angle sensor malfunctions, thus preventing the aircraft from flying, a method is proposed to calculate and analyze the airflow angle using aerodynamic data and acceleration, and to complete the comparison of triple-redundant signals, thereby improving the reliability of the system.
[0006] Technical Solution: To achieve the above-mentioned objectives, this invention proposes a flow angle voting method based on analytical redundancy. The method utilizes existing aerodynamic data of the aircraft, combined with the normal overload and lateral overload output from the airborne acceleration sensor, and calculates the analytical flow angle using analytical redundancy. This is then compared with the flow angle signals output from two sets of flow angle sensors using triple redundancy to obtain a correct flow angle value, thereby improving the reliability of the system.
[0007] Furthermore, the airflow angle is analyzed and combined with the two sets of airflow angle signals measured by the airborne airflow angle sensor to form a triplet airflow angle signal; the voting value of the airflow angle signal is obtained by using the triplet signal "three-to-two" comparison method.
[0008] Furthermore, the resolving airflow angle includes the resolving angle of attack and the resolving sideslip angle; The process of calculating the analytical angle of attack is as follows: using the correspondence between the normal overload increment and the angle of attack increment when the aircraft is flying horizontally, the normal overload data obtained by the airborne acceleration sensor is filtered and combined with the slope of the basic lift line of the aircraft to calculate the angle of attack increment; then, combined with the trim angle of attack of the aircraft at that altitude and speed obtained by offline calculation of the aerodynamic parameters, the analytical angle of attack of the aircraft can be obtained. The analytical calculation process for the sideslip angle is as follows: using the correspondence between lateral overload and sideslip angle during horizontal flight, the lateral overload data obtained by the airborne acceleration sensor is filtered and combined with the slope relationship between the basic lateral force of the aircraft and the sideslip angle to calculate the sideslip angle.
[0009] Furthermore, the analytical angle of attack calculation process is as follows: Step S11: Obtain the relationship curve between the aircraft's lift coefficient and angle of attack; based on the relationship curve, the slope of the lift coefficient curve can be approximately calculated. ; Step S12: Calculate the equivalent overload of the aircraft at that speed during level flight based on the relationship between angle of attack and lift. , Where m is the current weight of the aircraft. Current airspeed The atmospheric density is at the aircraft's current altitude, and S is the wing area. Step S13: When the angle of attack changes, the aircraft generates a corresponding normal overload increment. , The normal overload increment is given by g, where g is the acceleration due to gravity; the angle of attack increment can then be obtained. The current analytical angle of attack of the aircraft is: , The angle of attack for the current flight state point.
[0010] Furthermore, the calculation process for the analytical sideslip angle is as follows: Step S21: Obtain the relationship curve between the aircraft's side force coefficient and sideslip angle. Based on this curve, the slope of the side force coefficient curve can be calculated. ; Step S22: Calculate the equivalent sideslip angle of the aircraft at that speed during level flight based on the relationship between the sideslip angle and the lateral force. , Where m is the current weight of the aircraft. Current airspeed The atmospheric density is at the aircraft's current altitude, and S is the wing area. Step S23: When the aircraft is in level flight, lateral forces generate lateral overload. The analytical sideslip angle can be obtained. .
[0011] Furthermore, the relationship curves between the aircraft's lift coefficient and angle of attack, and between the aircraft's side force coefficient and sideslip angle, can be obtained through CFD calculations or wind tunnel tests.
[0012] Furthermore, the "three-judgment-two" discrimination method adopts the following judgment logic: If the triple redundancy values of the signal differ significantly, and each value deviates from the threshold of the other two, then the angle of attack voting value is... Sideslip angle voting value ; If two of the signal redundancy values are very close to each other and within the threshold, while the others are very close and exceed the threshold, then the voting value of the airflow angle signal is the average of the two values with the smallest difference. If the three values of the signal redundancy are very close and none of them exceed the limit, then the voting value of the airflow angle signal is the average of the three values.
[0013] Technical benefits: 1) The calculation of airflow angle by using the basic aerodynamic parameters of the aircraft improves the accuracy and stability of airflow angle calculation compared to the airflow angle calculation method that combines three-axis velocity and attitude angle. 2) The use of a triple-redundancy "three-judgment-two" method to select a suitable airflow angle signal improves the accuracy of the airflow angle signal and enhances the reliability of the system. Attached Figure Description
[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0015] Figure 1 This is the lift coefficient curve; Figure 2 The curve shows the lateral force coefficient. Figure 3 This is a logic diagram for the "three-judgment-two-judgment" method. Among them, (a) is the decision logic subgraph when all three redundancy values exceed the limit; (b) is the decision logic subgraph when a single value exceeds the limit (the difference between the two values is within the threshold); and (c) is the decision logic subgraph when none of the three redundancy values exceed the limit. Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0017] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.
[0018] Participate in the attached Figures 1-3 In the specific implementation of this invention, a flow angle voting method based on analytical redundancy is proposed. The method utilizes the aircraft's existing aerodynamic data, combined with the normal overload and lateral overload output by the airborne acceleration sensor, to calculate the analytical flow angle using analytical redundancy. This is then compared with the flow angle signals output by two sets of flow angle sensors using triple redundancy to finally obtain a correct flow angle value, thereby improving the reliability of the system.
[0019] For calculating the analytical angle of attack, the relationship curve between the aircraft's lift coefficient and the angle of attack is first obtained through CFD calculations or wind tunnel tests, such as... Figure 1 As shown. Based on the relationship curve between lift coefficient and angle of attack, the slope of the lift coefficient curve can be approximately obtained. Based on the relationship between angle of attack and lift during level flight, the equivalent overload of the aircraft at that speed during level flight is calculated. , Where m is the current weight of the aircraft. Current airspeed Let S be the atmospheric density at the aircraft's current altitude, and S be the wing area. When the angle of attack changes, the aircraft experiences a corresponding increase in normal overload. , Let g be the normal overload increment, and g be the acceleration due to gravity. The angle of attack increment can then be obtained. The aircraft's current analytical angle of attack is... , The angle of attack for the current flight state point.
[0020] For the calculation of analytical sideslip angle, the relationship curve between the aircraft's side force coefficient and sideslip angle is first obtained through CFD calculations or wind tunnel tests, such as... Figure 2 As shown. Based on the relationship curve between the lateral force coefficient and the sideslip angle, the slope of the lateral force coefficient curve can be obtained. The equivalent sideslip angle of the aircraft at that speed during level flight is calculated based on the relationship between the sideslip angle and the lateral force. , Where m is the current weight of the aircraft. Current airspeed Let S be the atmospheric density at the aircraft's current altitude, and S be the wing area. When the aircraft is in level flight, lateral forces generate lateral overload. The analytical sideslip angle can be obtained. .
[0021] In practical implementation, the angle of attack and sideslip angle can be filtered. The filter can generally be selected as follows: .
[0022] The airflow angle is analyzed and combined with the two sets of airflow angle signals measured by the airborne airflow angle sensor to form a triplet airflow angle signal. The signal voting value is obtained by using a "three-judgment-two" method.
[0023] In the specific implementation of this invention, the "three-judgment-two" discrimination method adopts the following determination method: If the redundancy values of the signals differ significantly, such as Figure 3 As shown in (a), each value exceeds the threshold from the other two values, at which point the angle of attack voting value is... Sideslip angle voting value ; If two values in the signal redundancy are very close in value, such as Figure 3 As shown in (b), within the threshold, the other values are all very different and exceed the threshold. At this time, the voting value of the airflow angle signal is the average of the two values with the smallest difference.
[0024] If the three values of the signal redundancy are very small, such as Figure 3 As shown in (c), none of them exceeded the limit, and at this time the voting value of the airflow angle signal is the average of the three values.
[0025] In the specific implementation process, the preset threshold is calibrated according to the aircraft model and flight conditions, and the value range is 0.3°~1.0°; two sets of airflow angle sensors are distributed on both sides of the aircraft fuselage or nose, forming a dual-redundant sensor design; the airborne acceleration sensor is a sensor originally configured on the aircraft, and no additional hardware is required.
[0026] The above specific embodiments or examples are only used to explain the technical solutions of the present invention and are not intended to limit the present application. Parts not described in detail are considered to be conventional technical means or common knowledge in the field. It can be understood by those skilled in the art that, based on the design concept of the present application, the technical solutions described in the foregoing embodiments can be adapted or some or all of the technical features can be equivalently replaced. These modifications, equivalent replacements, and adaptive improvements do not depart from the technical essence of the present invention and should all be covered within the protection scope of the present application.
Claims
1. A flow angle voting method based on analytical redundancy, characterized in that, Includes the following steps: Using existing aerodynamic data of the aircraft, combined with the normal and lateral overload output from the airborne acceleration sensor, the analytical airflow angle is calculated using the analytical redundancy method. The analytical airflow angle is combined with the airflow angle signals output from two sets of airflow angle sensors to form a triple redundancy airflow angle signal. The triple redundancy airflow angle signal is voted on using a "three-judgment-two" comparison method to obtain the correct airflow angle value. The analytical airflow angle includes the analytical angle of attack and the analytical sideslip angle.
2. The analytical redundancy based airflow angle voting method of claim 1, wherein, The process of calculating the analytical angle of attack is as follows: obtain the relationship curve between the aircraft's lift coefficient and angle of attack, and approximate the slope of the lift coefficient curve based on the relationship curve; calculate the equivalent overload of the aircraft at the current speed during level flight based on the relationship between the angle of attack and lift during level flight; obtain the normal overload increment through the airborne acceleration sensor, and calculate the angle of attack increment in combination with the gravitational acceleration; and obtain the analytical angle of attack by combining the trim angle of attack at the current flight state point.
3. The airflow angle voting method based on analytical redundancy as described in claim 2, characterized in that, The analytical angle of attack calculation process is as follows: Step S11, obtaining a lift coefficient versus angle of attack curve of the aircraft; according to the lift coefficient versus angle of attack curve, a lift coefficient curve slope can be approximately obtained ; Step S12, the equivalent overload of the airplane at the speed is calculated according to the relationship between the angle of attack and the lift at the time of the level flight , ; wherein m is the current weight of the airplane, is the current airspeed, is the atmospheric density at the current height of the airplane, and S is the wing area; Step S13: When the angle of attack changes, the aircraft generates a corresponding normal overload increment. , The normal overload increment is given by g, where g is the acceleration due to gravity; the angle of attack increment can then be obtained. The aircraft's current analytical angle of attack is: , The angle of attack for the current flight state point.
4. The analytical redundancy based air flow angle voting method of claim 1, wherein, The analytical calculation process for the sideslip angle is as follows: using the correspondence between lateral overload and sideslip angle during horizontal flight, the lateral overload data obtained by the airborne acceleration sensor is filtered and combined with the slope relationship between the basic lateral force of the aircraft and the sideslip angle to calculate the sideslip angle.
5. The airflow angle voting method based on analytical redundancy as described in claim 4, characterized in that, The analytical calculation process for the sideslip angle is as follows: Step S21: Obtain the relationship curve between the aircraft's side force coefficient and sideslip angle. Based on this curve, the slope of the side force coefficient curve can be calculated. ; Step S22: Calculate the equivalent sideslip angle of the aircraft at that speed during level flight based on the relationship between the sideslip angle and the lateral force. , Where m is the current weight of the aircraft. Current airspeed The atmospheric density is at the aircraft's current altitude, and S is the wing area. Step S23, when the airplane is in level flight, the side force generates a lateral overload, , the side slip angle can be analyzed .
6. A method for resolving the angle of airflow based on the excess margin of the voting table, as claimed in claim 1, wherein, The airflow angle is analyzed and combined with the two sets of airflow angle signals measured by the airborne airflow angle sensor to form a triplet airflow angle signal; the voting value of the airflow angle signal is obtained by using the triplet signal "three-to-two" comparison method.
7. A method for resolving the angle of airflow based on the excess margin of the voting method, as claimed in claim 5, wherein, The relationship curves between the lift coefficient and angle of attack of an aircraft, and between the side force coefficient and sideslip angle of an aircraft, can be obtained through CFD calculations or wind tunnel tests.
8. A method for resolving the angle of airflow based on the excess margin of the voting table, as claimed in claim 1 or 6, wherein, The "three-judgment-two-criteria" method uses the following judgment logic: If the signal three redundancy values are all very different, and each value is more than a threshold from the other two values, then the angle of attack vote value , the sideslip angle vote value ; If two of the signal redundancy values are very close to each other and within the threshold, while the others are very close and exceed the threshold, then the voting value of the airflow angle signal is the average of the two values with the smallest difference. If the three values of the signal redundancy are very close and none of them exceed the limit, then the voting value of the airflow angle signal is the average of the three values.
9. The analytical margin based airflow angle voting method of claim 1, wherein, Two sets of airflow angle sensors are distributed on both sides of the aircraft fuselage or nose, forming a dual-redundant sensor design; the airborne acceleration sensor is a sensor originally configured on the aircraft.