A distributed sideslip angle measurement device and method for large transport aircraft

Abstract

This invention discloses a device and method for distributed measurement of the sideslip angle of a large transport aircraft. The measurement method includes: acquiring pressure data measured by three probes; determining the dimensionless sensitivity coefficients of the three probes based on the pressure data and calculating the absolute value of the differences between them; determining whether a corresponding probe is faulty based on the magnitude of the difference between the absolute values ​​and a predetermined threshold; if a fault is found, excluding the data measured by that probe and calculating atmospheric data based on the pressure values ​​measured by the remaining probes. The measurement method provided by this invention includes acquiring the pressure data of the probes, calculating the dimensionless sensitivity coefficient of the probe, and using the dimensionless sensitivity coefficient to determine whether the probe is faulty, forming a redundant software algorithm design, thereby ensuring the accuracy of the pressure data, improving the measurement precision, and making up for the lack of current sideslip angle measurement schemes for large transport aircraft and the imperfect redundancy design.

Description

Technical Field

[0001] This invention relates to the field of atmospheric data measurement for aircraft, and particularly to a method and apparatus for measuring the sideslip angle of incoming flow in a distributed manner for large transport aircraft. Background Technology

[0002] Accurate atmospheric data measurement is of paramount importance for flight control, navigation, and system analysis of modern aircraft. Currently, mainstream atmospheric data systems primarily consist of traditional wind vane-type mechanical sensors and newly developed embedded atmospheric data systems. Traditional wind vane-type mechanical sensors suffer from low response speed and poor measurement accuracy, making them increasingly unsuitable for modern aircraft. Embedded atmospheric data systems are better suited for aircraft requiring high-speed, high-angle-of-attack, and highly maneuverable flight, but are not suitable for the large transport aircraft commonly found today.

[0003] When measuring incoming atmospheric parameters using commonly used atmospheric data systems, angle of attack has always been a crucial parameter due to dangerous operating conditions such as stall, while sideslip angle has been relatively neglected. Even large transport aircraft currently available are equipped with angle of attack sensors, while sideslip angle measurement has relied on auxiliary methods such as inertial navigation systems. However, in the certification process for large transport aircraft, accurate measurement of the incoming sideslip angle is necessary to meet the requirements of CCAR-25-R4 "Airworthiness Standards for Transport Category Aircraft".

[0004] In practical applications, atmospheric data systems are prone to malfunctions such as pressure line blockages and atmospheric data exceeding the measurement range in harsh flight environments. When atmospheric data measurements are abnormal and the system cannot autonomously diagnose and isolate such erroneous atmospheric data, the incorrect atmospheric data will cause the flight control system to make incorrect judgments, which may seriously lead to flight accidents. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a distributed measurement method and apparatus for large transport aircraft that ensures the accuracy and precision of the incoming flow sideslip angle calculation.

[0006] To achieve the above objectives, in one aspect, the present invention provides a distributed measurement device for the sideslip angle of an aircraft, comprising:

[0007] The acquisition unit uses a five-hole probe as the sideslip angle sensor. Each probe includes five pressure measuring holes arranged in a cross shape to acquire the measured pressure data.

[0008] The first determining unit is used to determine the dimensionless sensitivity coefficients of the three sets of sideslip angle sensors based on the pressure data distribution.

[0009] The first calculation unit is used to calculate the difference between the dimensionless sensitivity coefficients of the three sets of sideslip angle sensors and take the absolute value.

[0010] The second determining unit is used to determine whether the corresponding sideslip angle sensor is faulty based on the magnitude of the difference between the absolute values ​​of each sensor and a predetermined threshold.

[0011] The second calculation unit is used to calculate atmospheric data based on the pressure values ​​measured by the remaining sideslip angle sensors after the faulty sideslip angle sensor has been eliminated.

[0012] Three sets of sideslip angle sensors are arranged in a triangle below the nose of the aircraft; each sideslip angle sensor can calculate the sideslip angle independently, forming a triple redundancy hardware design.

[0013] Considering the aerodynamic interference of the aircraft nose on the sideslip angle sensor, the placement of the sideslip angle sensor is optimized.

[0014] The aircraft's nose amplifies the sideslip angle of the incoming flow directly below; a sideslip angle sensor is placed directly below to improve the accuracy of the incoming flow sideslip angle calculation within a small angle range;

[0015] The aircraft nose has a shift effect on the sideslip angle of the incoming flow from the side and below; two sideslip angle sensors are symmetrically arranged at a predetermined initial deflection angle on the side and below to improve the calculation range of the sideslip angle;

[0016] On the other hand, a distributed measurement method for aircraft sideslip angle is provided, including:

[0017] Acquire pressure data measured by three sets of sideslip angle sensors;

[0018] The dimensionless sensitivity coefficients of the three sets of sideslip angle sensors were determined based on the pressure data.

[0019] Calculate the difference between the dimensionless sensitivity coefficients of the three sets of sideslip angle sensors and take the absolute value;

[0020] The presence of a fault in the corresponding sideslip angle sensor is determined by the magnitude of the difference between the absolute values ​​of each sensor and a predetermined threshold.

[0021] If a fault exists, the data measured by that sideslip angle sensor is excluded, and atmospheric data is calculated based on the pressure values ​​measured by the remaining sideslip angle sensors.

[0022] As a preferred technical solution, determining the dimensionless sensitivity coefficients of the three sets of sideslip angle sensors based on the pressure data distribution further includes:

[0023] Determine the angle of attack sensitivity coefficient according to formula (1).

[0024]

[0025] Determine the sensitivity coefficient of the sideslip angle according to formula (3).

[0026]

[0027] In the formula, K α K is the angle of attack sensitivity coefficient. β P1 is the pressure value of the middle pressure measuring hole; P2 and P4 are the pressure values ​​of the two pressure measuring holes in the vertical direction; P3 and P5 are the pressure values ​​of the two pressure measuring holes in the horizontal direction.

[0028] Based on the above technical solution, preferably, if a fault exists, after excluding the data measured by the sideslip angle sensor, atmospheric data is calculated based on the pressure values ​​measured by the remaining sideslip angle sensors, further including:

[0029] The sideslip angle of the remaining sideslip angle sensor is determined according to formula (4).

[0030] β=C1+C2K β +C3K α +C4K β 2 +C5K β K α +C6K α 2 +C7K β 3 +C8K β 2 K α +C9K β K α 2 +C 10 K α 3 (4)

[0031] In the formula, C k These are the probe calibration coefficients; each formula contains a maximum of 10 correction coefficients, which are related to the sideslip angle sensor calibration results. The accurate calculation of different sideslip angles β by the sideslip angle sensor is influenced by K. β K α The combined effect of the two parameters.

[0032] If the number of remaining sideslip angle sensors is greater than 2, then take the average value of the sideslip angle calculated by all sideslip angle sensors.

[0033] As a preferred technical solution, determining whether a corresponding sideslip angle sensor is faulty based on the magnitude of the difference between the absolute values ​​of each sensor and a predetermined threshold further includes:

[0034] If the absolute value of the difference is less than or equal to the predetermined threshold, it indicates that the two sets of sideslip angle sensors are fault-free.

[0035] If the absolute difference is greater than the predetermined threshold, it indicates that at least one set of sideslip angle sensors is faulty.

[0036] The faulty sideslip angle sensor is determined by the intersection of the differences of the three absolute values ​​and a predetermined threshold size.

[0037] As a preferred technical solution, the preset threshold is the change in the dimensionless sensitivity coefficient of the calculated angle error within a range of 0.5°.

[0038] As a preferred technical solution, the presence or absence of a fault in the corresponding sideslip angle sensor is determined based on the magnitude of the difference between the absolute values ​​of each sensor and a predetermined threshold, followed by:

[0039] Repeat the above steps over a period of time. If the results of multiple measurements are the same, the measurement is correct; otherwise, measure again.

[0040] The advantages of this invention compared to existing technologies are as follows: The sideslip angle sensor device and its arrangement provided by this invention conform to a triple-redundancy design. By utilizing aerodynamic interference from the flight nose, the accuracy of sideslip angle calculation is improved, and the calculation range of sideslip angle is expanded. Simultaneously, the sideslip angle measurement method provided by this invention acquires the pressure data from the sideslip angle sensor, calculates the dimensionless sensitivity coefficient of the sensor, and uses the dimensionless sensitivity coefficient to determine whether the sideslip angle sensor has malfunctioned. This forms a redundant software algorithm design, ensuring the accuracy of sideslip angle calculation. Attached Figure Description

[0041] Figure 1 This is a structural diagram of a device for measuring the sideslip angle of an aircraft according to an embodiment of the present invention.

[0042] Figure 2 This is a diagram showing the distribution of the five-hole probe pressure measuring holes, which serves as a sideslip angle sensor, in one embodiment of the present invention.

[0043] Figure 3 This is a schematic diagram showing the arrangement position of the sideslip angle sensor of the measuring device at the nose of the aircraft in one embodiment of the present invention;

[0044] Figure 4 This is a result of the aerodynamic interference effect of the aircraft nose at the arrangement position in a wind tunnel experiment provided in one embodiment of the present invention;

[0045] Figure 5 This is a flowchart of a method for measuring the sideslip angle of a large transport aircraft according to an embodiment of the present invention;

[0046] Figure 6This is a diagram showing the correspondence between the dimensionless sensitivity coefficients of three sets of sideslip angle sensors provided in one embodiment of the present invention. Detailed Implementation

[0047] 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 a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0048] Reference Figure 1 This embodiment provides a measuring device for the sideslip angle of a large transport aircraft, comprising:

[0049] Acquisition unit 100 is used to acquire pressure data measured by three sets of sideslip angle sensors; wherein each sideslip angle sensor is a five-hole probe, such as... Figure 2 As shown, each probe in this embodiment includes five pressure measuring holes 1-5, arranged in a cross shape, to collect corresponding pressure information P1 to P5 respectively.

[0050] The first determining unit 200 is used to determine the dimensionless sensitivity coefficients of the three sets of sideslip angle sensors based on the pressure data distribution.

[0051] The first calculation unit 300 is used to calculate the difference between the dimensionless sensitivity coefficients of the three sets of sideslip angle sensors and take the absolute value.

[0052] The second determining unit 400 is used to determine whether the corresponding sideslip angle sensor is faulty based on the magnitude of the difference between the absolute values ​​of each sensor and a predetermined threshold.

[0053] The second calculation unit 500 is used to calculate atmospheric data based on the pressure values ​​measured by the remaining sideslip angle sensors after the faulty sideslip angle sensor has been eliminated.

[0054] Reference Figure 3 This embodiment provides the arrangement of a sideslip angle measuring device for a large transport aircraft. The three sets of sideslip angle sensors are distributed in a triangle at the nose of the aircraft. Based on wind tunnel test results, the aerodynamic interference of the aircraft nose to the incoming flow is considered.

[0055] like Figure 4 As shown, the area directly below the nose of the aircraft exhibits an amplification effect on the incoming flow sideslip angle; the area to the side and rear of the nose of the aircraft exhibits an offset effect on the incoming flow sideslip angle.

[0056] A sideslip angle sensor is placed directly below the flow to calculate the incoming sideslip angle within a small angle range with high precision.

[0057] Two sideslip angle sensors are arranged on the lower side, and are installed at a predetermined initial deflection angle to correct for offset. In the example given in this embodiment, the predetermined initial deflection angle is 10°. This ensures the accuracy of the sideslip angle calculation over a large angle range. In the example given in this embodiment, the calculation range of the entire sideslip angle sensor system is ±35°.

[0058] Reference Figure 5 This embodiment also provides a method for measuring the sideslip angle of a large transport aircraft, including the following steps:

[0059] S10: Acquire pressure data measured by three sets of sideslip angle sensors;

[0060] It should be noted that this embodiment is based on the calculation principle of a five-hole probe, and the corresponding incoming flow sideslip angle information is obtained by calculating the pressure difference collected by the five pressure measuring holes at the probe head.

[0061] S20: Determine the dimensionless sensitivity coefficients of the three sets of sideslip angle sensors based on the pressure data;

[0062] In this embodiment, the calculation of the aircraft's sideslip angle data is used as an example for illustration. Specifically, the angle of attack sensitivity coefficients of the three sets of sideslip angle sensors are calculated according to formula (1-1).

[0063]

[0064] Then, calculate the sideslip angle sensitivity coefficients of the three sets of sideslip angle sensors according to formula (1-2).

[0065]

[0066] In the formula, K α K is the angle of attack sensitivity coefficient. β P1 is the pressure value of the middle pressure measuring hole; P2 and P4 are the pressure values ​​of the two pressure measuring holes in the vertical direction; P3 and P5 are the pressure values ​​of the two pressure measuring holes in the horizontal direction.

[0067] S30: Calculate the difference between the dimensionless sensitivity coefficients of the three sets of sideslip angle sensors and take the absolute value;

[0068] Specifically, for the aircraft's sideslip angle, the sensitivity coefficient K of the aircraft's sideslip angle is calculated. β The difference between them is calculated, and the absolute value of the difference is taken to obtain |B1|, |B2|, and |B3|.

[0069] S40: Determine whether the corresponding sideslip angle sensor is faulty based on the magnitude of the difference between the absolute values ​​of each sensor and a predetermined threshold.

[0070] Specifically, for the aircraft's sideslip angle, |B1|, |B2|, and |B3| are compared with a preset threshold Z3. In this embodiment, the selection criteria for the preset threshold are related to the size of the sideslip angle sensor itself, manufacturing errors, and the required measurement accuracy. Generally, a sideslip angle sensitivity coefficient K with a calculated angle error within the range of 0.5° is selected. β The change amount is a predetermined threshold. In the example given in this embodiment, the predetermined threshold Z3 is 1.

[0071] If the values ​​of |B1|, |B2|, and |B3| are all less than the predetermined threshold Z3, it indicates that the calculated sideslip angle results obtained by the three sets of sideslip angle sensors are similar, which means that all three sets of sideslip angle sensors are normal. Figure 6 The table shows the correspondence between the three sets of sideslip angle sensors. Other comparison results and related issues are shown in Table 1.

[0072] Table 1

[0073] <![CDATA[K β Difference Judgment Corresponding question <![CDATA[|B1|、|B2|、|B3|<Z3]]> No fault <![CDATA[|B3|>Z3]]> 2, 3 difference warning <![CDATA[|B2|>Z3]]> 1.3 Difference Early Warning <![CDATA[|B1|>Z3]]> 1.2 Difference Warning <![CDATA[|B2|、|B3|>Z3]]> 3 faults <![CDATA[|B1|、|B3|>Z3]]> 2 Faults <![CDATA[|B1|、|B2|>Z3]]> 1 Fault <![CDATA[|B1|、|B2|、|B3|>Z3]]> Two or more groups have problems

[0074] It should be noted that 1, 2, and 3 in Table 1 correspond to... Figure 3 Sideslip angle sensor 1, sideslip angle sensor 2, and sideslip angle sensor 3 are included.

[0075] In some other embodiments, in order to improve the robustness of the software system, the above steps can be repeated continuously over a period of time. If the results of multiple measurements are the same, it means that the measurement is correct; otherwise, the measurement is repeated.

[0076] S50: If a fault exists, the atmospheric data is calculated based on the pressure values ​​measured by the remaining probes after excluding the data measured by that probe.

[0077] Specifically, after troubleshooting,

[0078] The sideslip angle of the flow can be calculated using formula (2-1).

[0079] β=C1+C2K β +C3K α +C4K β 2 +C5K β K α +C6K α 2 +C7K β 3 +C8K β 2 K α +C9K β K α 2 +C 10 Kα 3 (2-1)

[0080] In the formula, C k This refers to the probe calibration coefficient;

[0081] It should be noted that if the number of remaining sideslip angle sensors is greater than 2, the average value of the sideslip angle calculated by all sideslip angle sensors shall be taken.

[0082] The measurement method provided by this invention acquires pressure data from a sideslip angle sensor, calculates the dimensionless sensitivity coefficient of the sideslip angle sensor, and uses the dimensionless sensitivity coefficient to determine whether the sideslip angle sensor has malfunctioned, thereby ensuring the accuracy of the pressure data and improving the measurement precision.

[0083] In addition, embodiments of the present invention also provide a computer-readable storage medium, wherein the computer-readable storage medium may store a program that, when executed, includes some or all of the steps of any of the aircraft atmospheric data measurement methods described in the above method embodiments.

[0084] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0085] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0086] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, which may include: flash drive, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0087] An exemplary flowchart of a method for measuring atmospheric data of an aircraft according to an embodiment of the present invention has been described above with reference to the accompanying drawings. It should be noted that the numerous details included in the above description are merely illustrative of the invention and not intended to limit it. In other embodiments of the invention, the method may have more, fewer, or different steps, and the order, inclusion, function, and other relationships between the steps may differ from those described and illustrated.

Claims

1. A distributed measurement device for measuring the sideslip angle of incoming flow in a large transport aircraft, characterized in that, include: The acquisition unit uses a five-hole probe as the sideslip angle sensor. Each probe includes five pressure measuring holes arranged in a cross shape to acquire the measured pressure data. The first determining unit is used to determine the dimensionless sensitivity coefficients of the three sideslip angle sensors based on the pressure data. include: Determine the angle of attack sensitivity coefficient according to formula (1). Determine the sensitivity coefficient of the sideslip angle according to formula (2). In the formula, K α K is the angle of attack sensitivity coefficient. β P1 is the pressure value of the intermediate pressure measuring hole, and P2 is the sensitivity coefficient of the side slip angle. P4 represents the pressure values ​​of the two pressure measuring holes in the vertical direction; P3 and P5 represent the pressure values ​​of the two pressure measuring holes in the horizontal direction; among them, the three sideslip angle sensors are distributed in a triangle below the nose of the aircraft; each sideslip angle sensor can calculate the sideslip angle independently, forming a triple redundancy hardware design; one sideslip angle sensor is mounted directly below; the two sideslip angle sensors are mounted on the sides symmetrically. The first calculation unit is used to calculate the difference between the dimensionless sensitivity coefficients of the three sideslip angle sensors and take the absolute value; the second determination unit is used to determine whether the corresponding sideslip angle sensor is faulty based on the magnitude of the difference between the absolute values ​​and a predetermined threshold. The second calculation unit is used to calculate atmospheric data based on the pressure values ​​measured by the remaining sideslip angle sensors after the faulty sideslip angle sensor has been eliminated.

2. The measuring device according to claim 1, characterized in that: The nose of the aircraft amplifies the sideslip angle of the incoming flow directly below. A sideslip angle sensor is placed directly below to improve the accuracy of the incoming flow sideslip angle calculation within a small angle range; The aircraft nose has a shifting effect on the sideslip angle of the incoming flow from below and to the side; Two sideslip angle sensors are symmetrically arranged on the lower side to improve the calculation range of the sideslip angle.

3. A method for measuring the sideslip angle of a large transport aircraft using a distributed measurement system, characterized in that, include: Acquire pressure data measured by three sideslip angle sensors; The dimensionless sensitivity coefficients of the three sideslip angle sensors are determined based on the pressure data, including: Determine the angle of attack sensitivity coefficient according to formula (1). Determine the sensitivity coefficient of the sideslip angle according to formula (2). In the formula, K α K is the angle of attack sensitivity coefficient. β P1 represents the pressure value of the central pressure sensor, P2 and P4 represent the pressure values ​​of the two pressure sensors in the vertical direction, and P3 and P5 represent the pressure values ​​of the two pressure sensors in the horizontal direction. The three sideslip angle sensors are arranged in a triangle below the nose of the aircraft. Each sideslip angle sensor can independently calculate the sideslip angle, forming a triple-redundant hardware design. One sideslip angle sensor is mounted directly below, and the other two are mounted symmetrically on either side. Calculate the difference between the dimensionless sensitivity coefficients of the three sideslip angle sensors and take the absolute value; The presence of a faulty sideslip angle sensor is determined by comparing the difference between the absolute values ​​of each sensor with a predetermined threshold. If a fault is found, the faulty sideslip angle sensor is isolated, and the incoming flow sideslip angle is calculated based on the remaining sideslip angle sensors, thus forming a redundant software algorithm design.

4. The measurement method according to claim 3, characterized in that, If a fault is found, the faulty sideslip angle sensor is eliminated, and atmospheric data is calculated based on the pressure values ​​measured by other sideslip angle sensors. Further steps include: The sideslip angle of each remaining sideslip angle sensor is determined according to formula (3). β=C1+C2K β +C3K α +C4K β 2 +C5K β K α +C6K α 2 +C7K β 3 +C8K β 2 K α +C9K β K α 2 +C 10 K α 3 (3) In the formula, C k These are the probe calibration coefficients; each formula contains a maximum of 10 correction coefficients, which are related to the calibration results of each sideslip angle sensor; the accurate calculation of different sideslip angles β by the sideslip angle sensor is influenced by K. β K α The combined effect of the two parameters; If the number of remaining sideslip angle sensors is greater than 2, then take the average value of the sideslip angle calculated by all sideslip angle sensors.

5. The measurement method according to claim 3, characterized in that, Determining whether a sideslip angle sensor is faulty based on the magnitude of the difference between the absolute values ​​of each sensor and a predetermined threshold further includes: If the absolute difference is less than or equal to the predetermined threshold, it indicates that the two corresponding sideslip angle sensors are not faulty. If the absolute difference is greater than a predetermined threshold, it indicates that at least one of the sideslip angle sensors is faulty. The faulty sideslip angle sensor is determined by the intersection of the differences of the three absolute values ​​and a predetermined threshold size.

6. The measurement method according to claim 5, characterized in that: The predetermined threshold is the change in the dimensionless sensitivity coefficient of the calculated angle error within a range of 0.5°.

7. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of a distributed measurement method for the sideslip angle of a large transport aircraft as described in any one of claims 3 to 6.

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