A dynamic verification method for airborne optical atmospheric data system

Abstract

The application provides a dynamic verification method of an airborne optical atmospheric data system, and belongs to the field of atmospheric data systems. The method comprises the following steps: when the airborne optical atmospheric data system is in a processing excitation mode, sending a flight data uploading command to the airborne optical atmospheric data system and reading flight data; when it is judged that the current flight data is sent, sending flight data frames to the airborne optical atmospheric data system in a fixed cycle according to the frame sequence number of the flight data; pre-processing the received spectral data of each optical lens to obtain the frequency of each optical lens and calculating the optical lens airspeed; obtaining the true airspeed calculation state by calculating the true airspeed and detecting the true airspeed calculation state; calculating the attack angle and detecting the calculated attack angle; calculating the sideslip angle and detecting the calculated sideslip angle. The application solves the problems of low efficiency, lack of dynamic performance evaluation, and large difference between the verification environment and the airborne environment of the existing algorithm verification method.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of air data systems, and particularly relates to a dynamic verification method of an airborne optical air data system. BACKGROUND

[0002] The airborne optical air data system is based on the laser Doppler wind detection principle, uses multi-lens to emit laser, receives scattered laser signals carrying optical axis airspeed information after interaction with the atmosphere, and obtains aircraft true airspeed, attack angle and sideslip angle information through specific algorithm processing of the laser signals and combination of an atmospheric parameter solution model. Compared with the traditional air data measurement method, the airborne optical air data system has the advantages of strong anti-interference ability, high reliability and wide comprehensive detection range, and has a broad application prospect on different types of aircraft.

[0003] The parameter solution accuracy of the airborne optical air data system is closely related to the optical air data processing algorithm, and therefore, verification simulation of the optical air data processing algorithm is crucial. At present, the algorithm verification methods for the airborne optical air data system mainly include static and dynamic verification methods. The static verification method is to emit a frequency-shifted signal to the fixed optical lens of the system through a coherent frequency-shift device, and the optical air data system can solve the airspeed corresponding to the single lens according to the frequency-shifted signal. However, this method needs to focus the optical lens, the operation process is cumbersome, and the attack angle and sideslip angle cannot be solved, and the dynamic performance is not evaluated. The dynamic verification method mainly fixes the optical air data system on a vehicle, compares the consistency of the vehicle speed and the true airspeed output by the optical air data system, and completes the evaluation of the algorithm. However, this method is limited by the vehicle speed, the dynamic verification cannot cover the speed envelope of the aircraft, and can only be verified on the ground, and cannot simulate the influence of high-altitude thin air, airflow disturbance and other factors on the parameter solution of the optical air data system, which has great limitations. SUMMARY

[0004] In view of the above problems in the prior art, the present application provides a dynamic verification method of an airborne optical air data system, which solves the problems of low efficiency, lack of dynamic performance evaluation and large difference between the verification environment and the airborne environment of the existing algorithm verification method, and effectively improves the algorithm verification efficiency and comprehensiveness.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is a dynamic verification method of an airborne optical air data system, comprising the following steps:

[0006] S1, determining whether the airborne optical air data system is in an excitation working mode, if yes, proceeding to S2, otherwise, ending the process;

[0007] S2, the PC end software sends a flight data upload command to the airborne optical atmospheric data system through an Ethernet interface, and the airborne optical atmospheric data system reads flight data from its non-volatile memory and uploads it to the PC end software through the Ethernet interface after receiving the upload command, wherein the flight data is flight data of the aircraft in a real atmospheric environment, which includes flight data frame number, spectrum data of the optical lens, true airspeed , angle of attack , and sideslip angle ; the optical lens includes a first optical lens, a second optical lens and a third optical lens;

[0008] S3, judge whether the current flight data is sent, if yes, go to S4, otherwise, end the process;

[0009] S4, the PC end software sends flight data frames to the airborne optical atmospheric data system in a fixed period T according to the frame number order of the flight data;

[0010] S5, the airborne optical atmospheric data system pre-processes the spectrum data of each optical lens received to obtain the frequency of each optical lens, and calculates the optical lens airspeed according to the frequency of the optical lens;

[0011] S6, calculate the true airspeed according to the airspeed of each optical lens, and detect the state of the calculated true airspeed;

[0012] S7, calculate the angle of attack according to the airspeed of each optical lens, and detect the calculated angle of attack;

[0013] S8, calculate the sideslip angle according to the airspeed of each optical lens, and detect the calculated sideslip angle, complete the dynamic verification of the airborne optical atmospheric data system.

[0014] The beneficial effects of the application are: in the product incentive mode, the PC end software obtains the historical real flight data of the airborne optical atmospheric data system through the Ethernet interface, and sends the flight data to the optical atmospheric data system in a fixed period according to the data frame number order, the airborne optical atmospheric data system calculates the true airspeed, angle of attack and sideslip angle according to the received optical lens spectrum data, and compares the calculation results with the consistency of the received flight data by setting a threshold to complete the dynamic verification and evaluation of the optical atmospheric data algorithm.

[0015] Further, the true airspeed , angle of attack and sideslip angle are the results of solving the spectrum data obtained from the FPGA in the normal working mode of the airborne optical atmospheric data system;

[0016] The expression of the spectrum data of the optical lens is as follows:

[0017] ;

[0018] wherein, denotes the signal-to-noise ratio of the spectrum data of the i-th optical lens, i denotes the frequency of the spectrum data of the i-th optical lens, i i ={1,2,3}, denotes the result obtained after performing fast Fourier transform on the time-domain signal.

[0019] Further, the expression of the air speed of the optical lens in S5 is as follows:

[0020] ;

[0021] wherein, denotes the air speed of the i-th optical lens, in units of m / s, i denotes the frequency of the i-th optical lens, ={1,2,3}, i i Further, the expression of the true air speed in S6 is as follows:

[0022]

[0023] ;

[0024] wherein, denotes the true air speed, in units of m / s, denotes the air speed of the first optical lens, in units of m / s, denotes the air speed of the second optical lens, in units of m / s, denotes the air speed of the third optical lens, in units of m / s.

[0025] Further, the calculated true air speed is detected, and specifically:

[0026] the difference between the calculated true air speed and the true air speed in the received flight data frame :

[0027] ;

[0028] If the difference is greater than a threshold value THRES_VT for 60 consecutive ms, the true air speed calculation state is set to abnormal, otherwise the true air speed calculation state is set to normal, wherein the threshold value THRES_VT = 1 m / s. ​​​​​​​​

[0029] The vacuum velocity is calculated The calculation state is reported to the PC terminal software through the Ethernet interface, and the detection of the calculated vacuum velocity calculation state is completed.

[0030] The beneficial effect of the above further scheme is that the consistency of the vacuum velocity calculation result and the flight data record result is compared, and the iterative optimization effect of the software algorithm is evaluated.

[0031] Further, the expression of the S7 attack angle is as follows:

[0032] ;

[0033] Wherein, represents the attack angle, and the unit is °, represents the airspeed of the third optical lens, and the unit is m / s, represents the airspeed of the first optical lens, and the unit is m / s.

[0034] Further, the calculated attack angle is detected, which is specifically:

[0035] The attack angle is calculated The difference between the received flight data frame and the attack angle :

[0036] ;

[0037] If the difference value is greater than the threshold value THRES_AOA for 60ms continuously, the attack angle is set to abnormal, otherwise the attack angle is set to normal, wherein the threshold value THRES_AOA=0.5°;

[0038] The attack angle calculation state is reported to the PC terminal software through the Ethernet interface, and the detection of the calculated attack angle is completed.

[0039] The beneficial effect of the above further scheme is that the consistency of the attack angle calculation result and the flight data record result is compared, and the iterative optimization effect of the software algorithm is evaluated.

[0040] Further, the expression of the S8 side slip angle is as follows:

[0041] ;

[0042] Wherein, represents the side slip angle, and the unit is °, represents the airspeed of the second optical lens, and the unit is m / s, ​represents the vacuum velocity, and the unit is m / s.

[0043] Further, the calculated sideslip angle is detected, which specifically is:

[0044] Calculate the sideslip angle The difference between the sideslip angle in the received flight data frame :

[0045] ;

[0046] If the difference is greater than the threshold THRES_AOS for 60 consecutive ms, the sideslip angle is set to abnormal calculation state, otherwise the sideslip angle is set to normal calculation state, wherein the threshold THRES_AOS = 0.5°.

[0047] The sideslip angle calculation state is reported to the PC end software through the Ethernet interface.

[0048] The beneficial effects of the above further scheme are: by comparing the consistency of the sideslip angle calculation result and the flight data record result, the iterative optimization effect of the software algorithm can be evaluated. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 is a flow chart of the method of the present application. DETAILED DESCRIPTION

[0050] The specific embodiments of the present application are described below to facilitate the understanding of the present application by those skilled in the art, but it should be clear that the present application is not limited to the scope of the specific embodiments, and for those skilled in the art, it is obvious that various changes are within the spirit and scope of the present application defined and determined by the appended claims, and all the inventions utilizing the concept of the present application are within the scope of protection.

[0051] EMBODIMENT

[0052] Based on the deficiencies in the background art, the present application provides a dynamic verification method of an airborne optical atmospheric data system, which obtains historical real flight data information stored by the optical atmospheric data system through PC terminal software, including flight data frame serial number, spectral data of three optical lenses, true airspeed, attack angle and sideslip angle; then the PC terminal software sends the flight data to the airborne optical atmospheric data system through an Ethernet interface at a fixed period T according to the frame serial number, the airborne optical atmospheric data system replaces the spectral data collected from the FPGA with the received spectral data of the three optical lenses to complete the calculation of the true airspeed, attack angle and sideslip angle, and sets a threshold to compare the calculation results with the flight data for consistency to complete data analysis and algorithm effect evaluation.

[0053] As shown in Figure 1 , the present application provides a dynamic verification method of an airborne optical atmospheric data system, which is implemented as follows:

[0054] S1, judge whether the airborne optical atmospheric data system processes the excitation working mode, if yes, go to S2, otherwise, end the process;

[0055] S2, send a flight data upload command to the airborne optical atmospheric data system by the PC terminal software through an Ethernet interface, the airborne optical atmospheric data system receives the upload command, reads the flight data from its own non-volatile memory and uploads it to the PC terminal software through the Ethernet interface, wherein the flight data is the flight data of the aircraft in the real atmospheric environment, which includes flight data frame serial number, spectral data of optical lenses, true airspeed , attack angle and sideslip angle ; the optical lenses include a first optical lens, a second optical lens and a third optical lens;

[0056] In this embodiment, the true airspeed , attack angle and sideslip angle are the results calculated from the spectral data obtained from the FPGA in the normal working mode of the airborne optical atmospheric data system;

[0057] The expression of the spectral data of the optical lens is as follows:

[0058] ;

[0059] Wherein, represents the signal-to-noise ratio of the i th optical lens spectral data, represents the frequency of the i th optical lens spectral data, i ={1,2,3}, represents the result obtained by performing fast Fourier transform on the time domain signal.

[0060] S3, judge whether the current flight data is sent, if yes, go to S4, otherwise, end the process;

[0061] S4, by PC software to send flight data frame to the airborne optical atmospheric data system according to the frame sequence number of flight data in fixed period T;

[0062] In this embodiment, the flight data frame includes the spectral data of three optical lenses, the true airspeed , attack angle and sideslip angle , wherein the period T=20ms.

[0063] S5, the received spectral data of each optical lens is preprocessed by the airborne optical atmospheric data system to obtain the frequency of each optical lens, and the optical lens airspeed is calculated according to the frequency of the optical lens;

[0064] In this embodiment, the expression of optical lens airspeed is as follows:

[0065] ;

[0066] wherein, represents the airspeed of the i-th optical lens, unit: m / s, i is the frequency of the i-th optical lens, ={1, 2, 3}. i i S6, the true airspeed is calculated according to the airspeed of each optical lens, and the calculation state of the calculated true airspeed is detected;

[0067] In this embodiment, the expression of true airspeed is as follows:

[0068]

[0069] ;

[0070] wherein, represents the true airspeed, unit: m / s, represents the airspeed of the first optical lens, unit: m / s, represents the airspeed of the second optical lens, unit: m / s, represents the airspeed of the third optical lens, unit: m / s.

[0071] In this embodiment, the calculation state of the calculated true airspeed is detected, which is specifically:

[0072] the difference between the calculated true airspeed and the received flight data frame true airspeed is calculated :​​

[0073] ;

[0074] If the difference value of the continuous 60 ms is greater than a threshold THRES_VT, the airspeed Vt calculated state is set as abnormal, otherwise, the airspeed Vt calculated state is set as normal, wherein the threshold THRES_VT = 1 m / s.

[0075] The airspeed Vt calculated state is reported to the PC terminal software through an Ethernet interface, so as to complete the detection of the calculated airspeed Vt calculated state.

[0076] S7, the angle of attack is calculated according to the airspeed of each optical lens, and the calculated angle of attack is detected.

[0077] In this embodiment, the expression of the angle of attack is as follows:

[0078] ;

[0079] Wherein, represents the angle of attack, and the unit is °, represents the airspeed of the third optical lens, and the unit is m / s, represents the airspeed of the first optical lens, and the unit is m / s.

[0080] In this embodiment, the calculated angle of attack is detected, which is specifically:

[0081] The angle of attack is calculated. The difference value between the angle of attack calculated and the angle of attack received in the flight data frame is:

[0082] ;

[0083] If the difference value of the continuous 60 ms is greater than a threshold THRES_AOA, the angle of attack AOA calculated state is set as abnormal, otherwise, the angle of attack AOA calculated state is set as normal, wherein the threshold THRES_AOA = 0.5 °.

[0084] The angle of attack AOA calculated state is reported to the PC terminal software through an Ethernet interface, so as to complete the detection of the calculated angle of attack.

[0085] S8, the sideslip angle is calculated according to the airspeed of each optical lens, and the calculated sideslip angle is detected, so as to complete the dynamic verification of the airborne optical atmospheric data system.

[0086] ​​​​​​​In this embodiment, the expression of the sideslip angle is as follows:

[0087]

[0088] wherein, represents the sideslip angle, in °, represents the true airspeed, in m / s, represents the true airspeed, in m / s.

[0089] In this embodiment, the calculated sideslip angle is detected, which is specifically:

[0090] Calculate the sideslip angle and the difference between the sideslip angle in the received flight data frame :

[0091]

[0092] If the difference is greater than a threshold THRES_AOS for 60 consecutive ms, the sideslip angle is set to abnormal calculation state, otherwise the sideslip angle is set to normal calculation state, wherein the threshold THRES_AOS = 0.5°;

[0093] The sideslip angle calculation state is reported to the PC terminal software through the Ethernet interface.

[0094] In summary, the present scheme solves the problems of low efficiency, lack of dynamic performance evaluation, and large difference between the verification environment and the airborne environment of the existing algorithm verification method, and effectively improves the algorithm verification efficiency and comprehensiveness.​​

Claims

1. A dynamic verification method for an airborne optical atmospheric data system, characterized in that: The following steps are involved: S1, determine whether the airborne optical atmospheric data system processes the excitation working mode, if so, enter S2, otherwise, end the process; S2. The PC software sends a flight data upload command to the airborne optical atmospheric data system through the Ethernet interface. After receiving the upload command, the airborne optical atmospheric data system reads the flight data from its own non-volatile memory and uploads it to the PC software through the Ethernet interface. The flight data is the flight data of the aircraft in the real atmospheric environment, which includes the flight data frame number, the spectrum data of the optical lens, the true airspeed, and the flight data frame number. , angle of attack and sideslip angle ; The optical lens includes a first optical lens, a second optical lens and a third optical lens; S3. Determine whether the current flight data has been sent. If so, proceed to S4. Otherwise, end the process. S4. The PC software sends the flight data frames to the airborne optical air data system in the order of the flight data frame numbers at a fixed period T. S5. The airborne optical atmospheric data system pre-processes the received spectrum data of each optical lens to obtain the frequency of each optical lens, and calculates the optical lens airspeed based on the frequency of the optical lens; S6. Calculate the true airspeed based on the airspeed of each optical lens, and test the calculated true airspeed calculation state; the testing of the calculated true airspeed calculation state is specifically as follows: Calculate true airspeed True airspeed in the received flight data frame The difference : ； If the difference is 60ms If it is greater than the threshold THRES_VT, the true airspeed is set. The calculation status is abnormal, otherwise set the true airspeed The calculation status is normal; True air speed The calculation status is reported to the PC software via the Ethernet interface to complete the detection of the calculated true airspeed calculation status; S7. Calculate the angle of attack based on the airspeed of each optical lens and test the calculated angle of attack. Test the calculated angle of attack, specifically: Calculating angle of attack The angle of attack in the received flight data frame The difference : ； If the difference is 60ms If it is greater than the threshold THRES_AOA, then the angle of attack is set The calculation status is abnormal, otherwise the angle of attack is set The calculation status is normal; angle of attack The calculation status is reported to the PC software via the Ethernet interface to complete the detection of the calculated angle of attack; S8. Calculate a sideslip angle based on the airspeed of each optical lens, and test the calculated sideslip angle to complete the dynamic verification of the airborne optical atmospheric data system. The testing of the calculated sideslip angle is specifically as follows: Calculating the sideslip angle The sideslip angle in the received flight data frame The difference : ； If the difference is 60ms If it is greater than the threshold THRES_AOS, the sideslip angle The calculation status is abnormal, otherwise the sideslip angle is set The calculation status is normal; The sideslip angle The calculation status is reported to the PC software through the Ethernet interface.

2. The dynamic verification method of an airborne optical air data system according to claim 1, characterized in that: True airspeed , angle of attack and sideslip angle This is the result of calculating the spectrum data obtained from the FPGA in the normal working mode of the airborne optical atmosphere data system; The expression of the spectrum data of the optical lens is as follows: ； in, Indicates the i The signal-to-noise ratio of the optical lens spectrum data, Indicates the i Optical lens spectrum data frequency, i ={1, 2, 3}, It represents the result obtained by fast Fourier transforming the time domain signal.

3. The dynamic verification method of an airborne optical air data system according to claim 1, characterized in that: The expression of the optical lens airspeed in S5 is as follows: ； in, Indicates the i The airspeed of an optical lens, in m / s, For the i The frequency of the optical lens, i ={1, 2, 3}.

4. The dynamic verification method of an airborne optical air data system according to claim 1, characterized in that: The expression of true air speed in S6 is as follows: ； in, Indicates true airspeed in m / s. Indicates the airspeed of the first optical lens, in m / s, Indicates the airspeed of the second optical lens, in m / s, Indicates the airspeed of the third optical lens, in m / s.

5. The dynamic verification method of an airborne optical air data system according to claim 4, characterized in that: Threshold THRES_VT = 1m / s.

6. The dynamic verification method of an airborne optical air data system according to claim 1, characterized in that: The expression of the angle of attack in S7 is as follows: ； in, represents the angle of attack in degrees, Indicates the airspeed of the third optical lens, in m / s, Indicates the airspeed of the first optical lens, in m / s.

7. The dynamic verification method of an airborne optical air data system according to claim 6, characterized in that: Threshold THRES_AOA = 0.5°.

8. The dynamic verification method of an airborne optical air data system according to claim 1, characterized in that: The expression of the sideslip angle in S8 is as follows: ； in, Indicates the sideslip angle in degrees. Indicates the airspeed of the second optical lens, in m / s, Indicates true airspeed in m / s.

9. The dynamic verification method of an airborne optical air data system according to claim 8, characterized in that: Threshold THRES_AOS=0.5°.

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