User terminal flight turntable dynamic response correction method and system based on model identification

Abstract

The application provides a user terminal flight turntable dynamic response correction method and system based on model identification, comprising the following steps: S1: selecting a test load for flight turntable response model identification according to the specifications of a test product, compiling a trigonometric function sweep excitation signal, driving the turntable to operate and collecting instruction and feedback data; S2: analyzing the turntable instruction and feedback data, calculating the amplitude error and phase error at each sweep frequency point, giving the order of the turntable response model, and identifying the turntable response model under the test load; S3: designing and optimizing the PID controller parameters according to the turntable response model, and connecting the PID controller to the forward control channel of the turntable to compensate and correct the dynamic response of the turntable. The application can improve the double-10-bandwidth tracking capability of the turntable through the form of turntable control instruction compensation as the test load and maintenance state change.

Description

Technical Field

[0001] This invention relates to the field of hardware-in-the-loop control, specifically to a user-end flight turntable dynamic response correction method and system based on model identification. Background Technology

[0002] The turntable is a core testing device in hardware-in-the-loop (HIL) simulation of aircraft. It is used to simulate pitch, yaw, and roll attitude angles during flight in real time, as well as the target's altitude and azimuth line-of-sight angles relative to the aircraft. Its dynamic tracking performance directly affects the reliability of the simulation test. Generally, the turntable motor servo is meticulously designed by the manufacturer to meet the testing requirements within a certain frequency band. Its servo control parameters are not disclosed to users, and users will specify the turntable specifications and conduct rigorous acceptance tests before purchasing. As the turntable's testing scenarios and maintenance conditions change, its dynamic response characteristics will change. If the turntable's bandwidth capability (amplitude exceeding or attenuating by 10%, phase leading or lagging by 10%) is exceeded, the reliability of the test results will be severely reduced.

[0003] To improve the tracking performance of flight turntables, manufacturers currently primarily optimize the internal servo control, applying different control parameters to different loads. However, as the number of experimental product lines increases, the problem of some operating conditions not being covered inevitably arises. Chen Songlin et al., in their paper "A Self-Calibration Control Method for Simulation Turntables Based on Accurate Identification of Model Parameters," attempted self-calibration control based on the turntable's own servo system. However, for users, the turntable system structure and control parameters are difficult to obtain. With turntable maintenance costs rising annually, and even the inability to continue receiving manufacturer maintenance services due to policy changes, there is an urgent need to design user-facing methods to improve turntable tracking response capabilities.

[0004] Patent document CN107065551B (application number: CN201710271289.4) discloses a self-calibrating control method for a simulation turntable based on accurate identification of model parameters. However, this invention requires explicit definition of the turntable servo system structure and control parameters, primarily targeting turntable design manufacturers. It is difficult to implement at the user end and does not employ an incremental PID calibration method. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for correcting the dynamic response of a user-end flight turntable based on model identification.

[0006] A method for correcting the dynamic response of a user-end flight turntable based on model identification, provided by the present invention, includes:

[0007] Step S1: Select the test load identified by the flight turntable response model according to the specifications of the test product, compile the trigonometric function sweep frequency excitation signal, drive the turntable to run and collect command and feedback data;

[0008] Step S2: Analyze the turntable commands and feedback data, calculate the amplitude error and phase error at each sweep frequency point, give the order of the turntable response model, and identify the turntable response model under the test load.

[0009] Step S3: Design and optimize the parameters of the incremental PID controller based on the turntable response model, and connect the PID controller in series with the turntable forward control channel to compensate and correct the dynamic response of the turntable.

[0010] Preferably, in step S1:

[0011] Step S1.1: The frequency sweep excitation signal uses a cosine function, and the formulas for position Pos, velocity Vel, and acceleration Acc are expressed as follows:

[0012] Pos = Acos(2πf·t)

[0013] Vel = -2πf·Asin(2πf·t)

[0014] Acc = -(2πf) 2 ·Acos(2πf·t)

[0015] Where A is the amplitude, f is the frequency, and t is the time;

[0016] Step S1.2: Design a constant acceleration mode, setting the acceleration amplitude of the cosine sweep frequency signal to the turntable's factory-set maximum acceleration a. max The preset ratio m of the indicator, combined with the maximum angular velocity v max The minimum allowable frequency f is calculated based on the constraints. min :

[0017] f min =ma max / (2πv max )

[0018] Step S1.3: Start sweeping the frequency in steps, rounding up from the minimum allowable frequency, until the frequency exceeds the double-ten bandwidth frequency f. max Then it stops. At each frequency point, the cosine sweep signal runs at a constant speed to the peak position within the first preset time period, waits at the peak position within the second preset time period, starts the excitation after the preset time, and ends after running a preset number of complete cycles.

[0019] Preferably, in step S2:

[0020] Step S2.1: Analyze the collected turntable commands and feedback data. At each scanning frequency point, find the amplitude and time of the command signal peaks Peaks_cp, Locs_cp, and the amplitude and time of the troughs Peaks_cn, Locs_cn; find the amplitude and time of the feedback signal peaks Peaks_op, Locs_op, and the amplitude and time of the troughs Peaks_on, Locs_on.

[0021] Step S2.2: Based on the amplitude and time of the peaks and troughs of the command and feedback signals, calculate the amplitude difference and phase difference at the scanning frequency points. The amplitude difference is calculated as follows:

[0022]

[0023] The phase difference is calculated as follows:

[0024]

[0025] Preferably, by combining the amplitude and phase differences at each scanning frequency, the turntable response transfer function is fitted using the invfreqs function in Matlab:

[0026]

[0027] Where Num represents the coefficients of the numerator polynomial of the fitted transfer function, Den represents the coefficients of the denominator polynomial of the fitted transfer function; n and d represent the orders of the numerator and denominator of the fitted transfer function, respectively; ω represents the angular velocity; and j represents the imaginary number.

[0028] Preferably, in step S3:

[0029] Step S3.1: Based on the identified turntable response transfer function, design a series PID correction controller, and adjust the PID control coefficients in the discrete domain in combination with the turntable control step size until the turntable performance meets the test requirements.

[0030] Step S3.2: When applying the calibration controller, incremental PID mode is used. Based on the position deviation between the command and the turntable feedback within the current three control cycles, the control increment is calculated:

[0031] Δu k =u k -u k-1 =K p (e k -e k-1 )+K i e k T+K d (e k -2e k-1 +e k-2 ) / T,k=1,2,3,…

[0032] Where T is the discrete control period of the turntable, k represents the discrete time, and u k e is the turntable command value at time k. k Let K be the deviation between the turntable command and feedback at time k. p K i and K d These are the proportional coefficient, integral coefficient, and derivative coefficient of the incremental PID controller;

[0033] This yields the corrected turntable control command u. k =u k-1 +Δu k This drives the turntable equipment to operate.

[0034] A user-end flight turntable dynamic response correction system based on model identification, provided by the present invention, includes:

[0035] Module M1: Select the test load identified by the flight turntable response model according to the specifications of the test product, compile the trigonometric function sweep frequency excitation signal, drive the turntable to run and collect commands and feedback data;

[0036] Module M2: Analyzes turntable commands and feedback data, calculates amplitude and phase errors at each sweep frequency point, and identifies the turntable response model under test load given the turntable response model order.

[0037] Module M3: Based on the turntable response model, design and optimize the parameters of the incremental PID controller, and connect the PID controller in series with the turntable forward control channel to compensate and correct the dynamic response of the turntable.

[0038] Preferably, in module M1:

[0039] Module M1.1: The frequency sweep excitation signal uses a cosine function, and the formulas for position Pos, velocity Vel, and acceleration Acc are as follows:

[0040] Pos = Acos(2πf·t)

[0041] Vel = -2πf·Asin(2πf·t)

[0042] Acc = -(2πf) 2 ·Acos(2πf·t)

[0043] Where A is the amplitude, f is the frequency, and t is the time;

[0044] Module M1.2: Design a constant acceleration mode, setting the acceleration amplitude of the cosine sweep frequency signal to the turntable's factory-set maximum acceleration a. max The preset ratio m of the indicator, combined with the maximum angular velocity v maxThe minimum allowable frequency f is calculated based on the constraints. min :

[0045] f min =ma max / (2πv max )

[0046] Module M1.3: Starts a frequency sweep by rounding up from the minimum allowed frequency, continuing until the frequency exceeds the double-ten bandwidth frequency f. max Then it stops. At each frequency point, the cosine sweep signal runs at a constant speed to the peak position within the first preset time period, waits at the peak position within the second preset time period, starts the excitation after the preset time, and ends after running a preset number of complete cycles.

[0047] Preferably, in module M2:

[0048] Module M2.1: Analyzes the acquired turntable commands and feedback data. At each scan frequency point, it finds the amplitude and time of the command signal peaks (Peaks_cp, Locs_cp) and the amplitude and time of the troughs (Peaks_cn, Locs_cn); it also finds the amplitude and time of the feedback signal peaks (Peaks_op, Locs_op) and the amplitude and time of the troughs (Peaks_on, Locs_on).

[0049] Module M2.2: Based on the amplitude and time of the peaks and troughs of the command and feedback signals, calculate the amplitude difference and phase difference at the scanning frequency points. The amplitude difference is calculated as follows:

[0050]

[0051] The phase difference is calculated as follows:

[0052]

[0053] Preferably, by combining the amplitude and phase differences at each scanning frequency, the turntable response transfer function is fitted using the invfreqs function in Matlab:

[0054]

[0055] Where Num represents the coefficients of the numerator polynomial of the fitted transfer function, Den represents the coefficients of the denominator polynomial of the fitted transfer function; n and d represent the orders of the numerator and denominator of the fitted transfer function, respectively; ω represents the angular velocity; and j represents the imaginary number.

[0056] Preferably, in module M3:

[0057] Module M3.1: Based on the identified turntable response transfer function, design a series PID correction controller, and adjust the PID control coefficients in the discrete domain in combination with the turntable control step size until the turntable performance meets the test requirements;

[0058] Module M3.2: When applying the calibration controller, incremental PID mode is used. Based on the position deviation between the command and the turntable feedback within the current three control cycles, the control increment is calculated.

[0059] Δu k =u k -u k-1 =K p (e k -e k-1 )+K i e k T+K d (e k -2e k-1 +e k-2 ) / T,k=1,2,3,…

[0060] Where T is the discrete control period of the turntable, k represents the discrete time, and u k e is the turntable command value at time k. k Let K be the deviation between the turntable command and feedback at time k. p K i and K d These are the proportional coefficient, integral coefficient, and derivative coefficient of the incremental PID controller;

[0061] This yields the corrected turntable control command u. k =u k-1 +Δu k This drives the turntable equipment to operate.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] 1. This invention provides a user-oriented dynamic response correction method for turntable equipment under current testing and usage conditions, without manufacturer intervention. It can improve the dual-ten bandwidth tracking capability through turntable control command compensation as the test load and maintenance status change.

[0064] 2. This invention adopts an incremental PID correction design, and the compensation control quantity is only related to the deviation of the three most recent commands and feedback, and there is no long-term cumulative error, ensuring the smooth start-up and operation of the turntable. Attached Figure Description

[0065] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0066] Figure 1 This is a flowchart of the user-end flight turntable dynamic response correction method based on model identification according to the present invention;

[0067] Figure 2 The example shows the position command curve of the cosine sweep frequency signal in the middle frame of the turntable;

[0068] Figure 3 The example shows the angular acceleration curve of the cosine sweep frequency signal in the middle frame of the turntable.

[0069] Figure 4 This describes the amplitude and timing of the peaks and troughs in the command and feedback data.

[0070] Figure 5 The comparison curves show the frame drive command (black), the fitted transfer function response (green), the actual feedback response before correction (red), and the actual feedback response after correction (pink) in the case study.

[0071] Figure 6 The Bode plots show the frequency response before and after cascaded PID correction. Detailed Implementation

[0072] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0073] Example 1:

[0074] This invention relates to hardware-in-the-loop (HIL) simulation testing technology for aircraft, and discloses a user-end flight turntable dynamic response correction method based on model identification. This method addresses the insufficient tracking capability of turntable equipment. In the absence of manufacturer intervention, it provides a user-end-oriented turntable dynamic response correction method based on the current testing and maintenance conditions of the flight turntable, effectively improving the turntable's bandwidth. Specific steps include: selecting a test load for constant acceleration cosine sweep frequency excitation testing, acquiring commands and feedback data; analyzing the test data, calculating the amplitude and phase differences at each sweep frequency point, and identifying the turntable transfer function model; designing series PID correction control parameters based on the transfer function model, and using incremental PID to compensate for the original turntable control commands to drive the turntable equipment.

[0075] According to the present invention, a user-end flight turntable dynamic response correction method based on model identification is provided, such as... Figures 1-6 As shown, it includes:

[0076] Step S1: Select the test load identified by the flight turntable response model according to the specifications of the test product, compile the trigonometric function sweep frequency excitation signal, drive the turntable to run and collect command and feedback data;

[0077] Specifically, in step S1:

[0078] Step S1.1: The frequency sweep excitation signal uses a cosine function, and the formulas for position Pos, velocity Vel, and acceleration Acc are expressed as follows:

[0079] Pos = Acos(2πf·t)

[0080] Vel = -2πf·Asin(2πf·t)

[0081] Acc = -(2πf) 2 ·Acos(2πf·t)

[0082] Where A is the amplitude, f is the frequency, and t is the time;

[0083] Step S1.2: Design a constant acceleration mode, setting the acceleration amplitude of the cosine sweep frequency signal to the turntable's factory-set maximum acceleration a. max The preset ratio m of the indicator, combined with the maximum angular velocity v max The minimum allowable frequency f is calculated based on the constraints. min :

[0084] f min =ma max / (2πv max )

[0085] Step S1.3: Start sweeping the frequency in steps, rounding up from the minimum allowable frequency, until the frequency exceeds the double-ten bandwidth frequency f. max Then it stops. At each frequency point, the cosine sweep signal runs at a constant speed to the peak position within the first preset time period, waits at the peak position within the second preset time period, starts the excitation after the preset time, and ends after running a preset number of complete cycles.

[0086] Step S2: Analyze the turntable commands and feedback data, calculate the amplitude error and phase error at each sweep frequency point, give the order of the turntable response model, and identify the turntable response model under the test load.

[0087] Specifically, in step S2:

[0088] Step S2.1: Analyze the collected turntable commands and feedback data. At each scanning frequency point, find the amplitude and time of the command signal peaks Peaks_cp, Locs_cp, and the amplitude and time of the troughs Peaks_cn, Locs_cn; find the amplitude and time of the feedback signal peaks Peaks_op, Locs_op, and the amplitude and time of the troughs Peaks_on, Locs_on.

[0089] Step S2.2: Based on the amplitude and time of the peaks and troughs of the command and feedback signals, calculate the amplitude difference and phase difference at the scanning frequency points. The amplitude difference is calculated as follows:

[0090]

[0091] The phase difference is calculated as follows:

[0092]

[0093] Specifically, by combining the amplitude and phase differences at each scanning frequency, the turntable response transfer function is fitted using the invfreqs function in Matlab:

[0094]

[0095] Where Num represents the coefficients of the numerator polynomial of the fitted transfer function, Den represents the coefficients of the denominator polynomial of the fitted transfer function; n and d represent the orders of the numerator and denominator of the fitted transfer function, respectively; ω represents the angular velocity; and j represents the imaginary number.

[0096] Step S3: Design and optimize the parameters of the incremental PID controller based on the turntable response model, and connect the PID controller in series with the turntable forward control channel to compensate and correct the dynamic response of the turntable.

[0097] Specifically, in step S3:

[0098] Step S3.1: Based on the identified turntable response transfer function, design a series PID correction controller, and adjust the PID control coefficients in the discrete domain in combination with the turntable control step size until the turntable performance meets the test requirements.

[0099] Step S3.2: When applying the calibration controller, incremental PID mode is used. Based on the position deviation between the command and the turntable feedback within the current three control cycles, the control increment is calculated:

[0100] Δu k =u k -u k-1 =K p (e k -e k-1 )+K i e k T+K d (e k -2e k-1 +e k-2 ) / T,k=1,2,3,…

[0101] Where T is the discrete control period of the turntable, k represents the discrete time, and u k e is the turntable command value at time k. k Let K be the deviation between the turntable command and feedback at time k. p K i and K dThese are the proportional coefficient, integral coefficient, and derivative coefficient of the incremental PID controller;

[0102] This yields the corrected turntable control command u. k =u k-1 +Δu k This drives the turntable equipment to operate.

[0103] Example 2:

[0104] Example 2 is a preferred embodiment of Example 1, and is used to illustrate the present invention in more detail.

[0105] The present invention also provides a model identification-based user-end flight turntable dynamic response correction system. The model identification-based user-end flight turntable dynamic response correction system can be implemented by executing the process steps of the model identification-based user-end flight turntable dynamic response correction method. That is, those skilled in the art can understand the model identification-based user-end flight turntable dynamic response correction method as a preferred embodiment of the model identification-based user-end flight turntable dynamic response correction system.

[0106] A user-end flight turntable dynamic response correction system based on model identification, provided by the present invention, includes:

[0107] Module M1: Select the test load identified by the flight turntable response model according to the specifications of the test product, compile the trigonometric function sweep frequency excitation signal, drive the turntable to run and collect commands and feedback data;

[0108] Specifically, in module M1:

[0109] Module M1.1: The frequency sweep excitation signal uses a cosine function, and the formulas for position Pos, velocity Vel, and acceleration Acc are as follows:

[0110] Pos = Acos(2πf·t)

[0111] Vel = -2πf·Asin(2πf·t)

[0112] Acc = -(2πf) 2 ·Acos(2πf·t)

[0113] Where A is the amplitude, f is the frequency, and t is the time;

[0114] Module M1.2: Design a constant acceleration mode, setting the acceleration amplitude of the cosine sweep frequency signal to the turntable's factory-set maximum acceleration a. max The preset ratio m of the indicator, combined with the maximum angular velocity v max The minimum allowable frequency f is calculated based on the constraints. min :

[0115] f min =ma max / (2πv max )

[0116] Module M1.3: Starts a frequency sweep by rounding up from the minimum allowed frequency, continuing until the frequency exceeds the double-ten bandwidth frequency f. max Then it stops. At each frequency point, the cosine sweep signal runs at a constant speed to the peak position within the first preset time period, waits at the peak position within the second preset time period, starts the excitation after the preset time, and ends after running a preset number of complete cycles.

[0117] Module M2: Analyzes turntable commands and feedback data, calculates amplitude and phase errors at each sweep frequency point, and identifies the turntable response model under test load given the turntable response model order.

[0118] Specifically, in module M2:

[0119] Module M2.1: Analyzes the acquired turntable commands and feedback data. At each scan frequency point, it finds the amplitude and time of the command signal peaks (Peaks_cp, Locs_cp) and the amplitude and time of the troughs (Peaks_cn, Locs_cn); it also finds the amplitude and time of the feedback signal peaks (Peaks_op, Locs_op) and the amplitude and time of the troughs (Peaks_on, Locs_on).

[0120] Module M2.2: Based on the amplitude and time of the peaks and troughs of the command and feedback signals, calculate the amplitude difference and phase difference at the scanning frequency points. The amplitude difference is calculated as follows:

[0121]

[0122] The phase difference is calculated as follows:

[0123]

[0124] Specifically, by combining the amplitude and phase differences at each scanning frequency, the turntable response transfer function is fitted using the invfreqs function in Matlab:

[0125]

[0126] Where Num represents the coefficients of the numerator polynomial of the fitted transfer function, Den represents the coefficients of the denominator polynomial of the fitted transfer function; n and d represent the orders of the numerator and denominator of the fitted transfer function, respectively; ω represents the angular velocity; and j represents the imaginary number.

[0127] Module M3: Based on the turntable response model, design and optimize the parameters of the incremental PID controller, and connect the PID controller in series with the turntable forward control channel to compensate and correct the dynamic response of the turntable.

[0128] Specifically, in module M3:

[0129] Module M3.1: Based on the identified turntable response transfer function, design a series PID correction controller, and adjust the PID control coefficients in the discrete domain in combination with the turntable control step size until the turntable performance meets the test requirements;

[0130] Module M3.2: When applying the calibration controller, incremental PID mode is used. Based on the position deviation between the command and the turntable feedback within the current three control cycles, the control increment is calculated.

[0131] Δu k =u k -u k-1 =K p (e k -e k-1 )+K i e k T+K d (e k -2e k-1 +e k-2 ) / T,k=1,2,3,…

[0132] Where T is the discrete control period of the turntable, k represents the discrete time, and u k e is the turntable command value at time k. k Let K be the deviation between the turntable command and feedback at time k. p K i and K d These are the proportional coefficient, integral coefficient, and derivative coefficient of the incremental PID controller;

[0133] This yields the corrected turntable control command u. k =u k-1 +Δu k This drives the turntable equipment to operate.

[0134] Example 3:

[0135] Example 3 is a preferred example of Example 1, and is used to illustrate the present invention in more detail.

[0136] This invention provides a model-based dynamic response correction method for user-end flight turntables, specifically designed to improve the turntable's dual-bandwidth capability, addressing current testing and operational conditions of turntable equipment. The model-based dynamic response correction method for user-end flight turntables includes the following steps:

[0137] S1. Select the test load identified by the flight turntable model according to the specifications of the test product, compile the trigonometric function sweep frequency excitation signal, drive the turntable to run and collect commands and feedback data.

[0138] S2. Analyze the turntable commands and feedback data, calculate the amplitude error and phase error at each sweep frequency point, and identify the turntable response model under the test load, given the turntable model order.

[0139] S3. Based on the turntable model, design and optimize the parameters of the incremental PID controller, and connect the PID controller in series with the turntable forward control channel to compensate and correct the dynamic response of the turntable.

[0140] In one specific implementation method, the trigonometric function sweep frequency signal is compiled as follows:

[0141] S11. To ensure stable and continuous speed during the turntable startup process, the frequency sweep excitation signal uses a cosine function, and its position, velocity, and acceleration formulas are expressed as follows:

[0142] Pos = Acos(2πf·t)

[0143] Vel = -2πf·Asin(2πf·t)

[0144] Acc = -(2πf) 2 ·Acos(2πf·t)

[0145] S12. Design a constant acceleration mode, setting the acceleration amplitude of the cosine sweep frequency signal to the turntable's factory-set maximum acceleration a. max 80% of the index, combined with the maximum angular velocity v max The minimum permissible frequency f is calculated based on the constraints. m in, i.e., f min =0.8a max / (2πv max ).

[0146] S13. Start sweeping the frequency in steps, rounding up from the minimum allowable frequency, until the frequency exceeds the double-ten bandwidth frequency f. max Then it stops. At each frequency point, the cosine sweep signal runs at a constant speed to the peak position for the first two seconds, waits at the peak position for the next two seconds, starts the excitation after 4 seconds, and ends after running 6 complete cycles.

[0147] In the case, the maximum angular acceleration of the turntable frame is 8000° / s², the maximum angular velocity is 600° / s, and the dual-ten bandwidth frequency is 8Hz. Then, the angular velocity of the excitation sweep signal is set to be constant at 6400° / s², the minimum allowable frequency is 1.7Hz, and the cosine excitation signal sweeps from 2.0Hz to 8.0Hz in 1.0Hz steps.

[0148] In one specific implementation measure, the turntable response model identification method is as follows:

[0149] S21. Analyze the collected turntable commands and feedback data. At each scanning frequency point, find the amplitude and time of the command signal peaks Peaks_cp, Locs_cp, and the amplitude and time of the troughs Peaks_cn, Locs_cn; find the amplitude and time of the feedback signal peaks Peaks_op, Locs_op, and the amplitude and time of the troughs Peaks_on, Locs_on.

[0150] S22. Based on the amplitude and time of the peaks and troughs of the command and feedback signals, calculate the amplitude difference and phase difference at the scanning frequency points. The amplitude difference is calculated as follows:

[0151]

[0152] 20 is a fixed coefficient. In control systems or signal processing, the amplitude difference is often converted to decibels (dB) using 20*log. For example, if the amplitude decreases to 1 / 10 of its original value, it is described as -20dB; if it decreases to 1 / 100 of its original value, it is described as -40dB.

[0153] The phase difference is calculated as follows:

[0154]

[0155] In this case study, the amplitude and phase differences at various frequency points within the turntable frame are statistically analyzed in the table below.

[0156] Frequency (Hz) 2.000 3.000 4.000 5.000 6.000 7.000 8.000 Amplitude (°) 40.529 18.013 10.132 6.485 4.503 3.308 2.533 Amplitude difference (dB) 0.067 0.168 0.291 0.424 0.619 0.878 1.185 Phase difference (°) -1.800 -2.713 -3.600 -4.500 -7.425 -8.663 -9.900

[0157] S23. Combining the amplitude and phase differences at various scanning frequencies, the turntable response transfer function is fitted using the invfreqs function in Matlab:

[0158]

[0159] In the formula, Num represents the coefficients of the numerator polynomial of the fitted transfer function, and Den represents the coefficients of the denominator polynomial of the fitted transfer function; n and d are the orders of the numerator and denominator of the fitted transfer function, respectively. 57.3 is an approximate conversion relationship between degrees and radians, where 180° corresponds to PI (3.1415926 rad), and 180 divided by 3.1415926 is approximately 57.3.

[0160] In this case study, a second-order circuit is used to simulate the turntable frame, resulting in the following dynamic response transfer function:

[0161]

[0162] The damping ratio of the frame in the fitted turntable is approximately 0.19, and the undamped natural frequency is approximately 131 rad / s. Comparing the fitted output data obtained from the actual commands through the fitted model with the actual collected feedback data shows that the red actual feedback and the green fitted output have good consistency.

[0163] In one specific implementation measure, the turntable compensation and correction method is as follows:

[0164] S31. Based on the identified turntable response transfer function, design a series PID correction controller. Adjust the PID control coefficients in the discrete domain, taking into account the turntable control step size, until the turntable performance meets the experimental requirements.

[0165] In the case study, for the turntable frame model identified by S23, a PID controller with parameters K is designed. p =2.5,K i =280,K d =0.015. The Bode plot of the frequency response of the turntable system before and after correction shows that its double-ten bandwidth has expanded from 6.7Hz to 22.4Hz.

[0166] S32. When applying the correction controller, incremental PID mode is used. The control increment is calculated based on the position deviation between the command and the turntable feedback within the current three control cycles. The formula is described as follows:

[0167] Δu k =u k -u k-1 =K p (e k -e k-1 )+K i e k T+K d (e k -2e k-1 +e k-2 ) / T

[0168] This yields the corrected turntable control command u. k =u k-1 +Δu k This drives the turntable equipment to operate.

[0169] For the same command input signal, comparing the tracking response before and after calibration shows that, compared to the red feedback curve before calibration, the pink response curve after calibration is more consistent with the black command curve, and the turntable tracking response capability is significantly improved.

[0170] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0171] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for correcting the dynamic response of a user-end flight turntable based on model identification, characterized in that, include: Step S1: Select the test load identified by the flight turntable response model according to the specifications of the test product, compile the trigonometric function sweep frequency excitation signal, drive the turntable to run and collect command and feedback data; Step S2: Analyze the turntable commands and feedback data, calculate the amplitude error and phase error at each sweep frequency point, give the order of the turntable response model, and identify the turntable response model under the test load. Step S3: Design and optimize the parameters of the incremental PID controller based on the turntable response model, and connect the PID controller in series with the turntable forward control channel to compensate and correct the dynamic response of the turntable. In step S1: Step S1.1: The frequency sweep excitation signal uses a cosine function, and the position... ,speed and acceleration The formula is expressed as: in, For amplitude, For frequency, For time; Step S1.2: Design a constant acceleration mode, setting the acceleration amplitude of the cosine sweep frequency signal to the turntable's factory-set maximum acceleration. The preset ratio m of the indicator, combined with the maximum angular velocity Limitations are imposed, and the minimum allowable frequency is calculated. : Step S1.3: Start sweeping the frequency in steps, rounding up from the minimum allowable frequency, until the frequency exceeds the double-ten bandwidth frequency. Then it stops. At each frequency point, the cosine sweep signal runs at a constant speed to the peak position within the first preset time period, waits at the peak position within the second preset time period, starts the excitation after the preset time, and ends after running a preset number of complete cycles.

2. The user-end flight turntable dynamic response correction method based on model identification according to claim 1, characterized in that, In step S2: Step S2.1: Analyze the acquired turntable commands and feedback data, and at each scanning frequency point, find the amplitude and time of the command signal peak. , The amplitude and time of the trough , ; Find the amplitude and time of the feedback signal peak. , The amplitude and time of the trough , ; Step S2.2: Based on the amplitude and time of the peaks and troughs of the command and feedback signals, calculate the amplitude difference and phase difference at the scanning frequency points. The amplitude difference is calculated as follows: The phase difference is calculated as follows: 。 3. The user-end flight turntable dynamic response correction method based on model identification according to claim 2, characterized in that: By combining the amplitude and phase differences at various scanning frequencies, the turntable response transfer function is fitted using the invfreqs function in Matlab. in, To fit the coefficients of the numerator polynomial of the transfer function, To fit the coefficients of the denominator polynomial of the transfer function; and These are the orders of the numerator and denominator of the fitted transfer function, respectively. Angular velocity, It is an imaginary number.

4. The user-end flight turntable dynamic response correction method based on model identification according to claim 1, characterized in that, In step S3: Step S3.1: Based on the identified turntable response transfer function, design a series PID correction controller, and adjust the PID control coefficients in the discrete domain in combination with the turntable control step size until the turntable performance meets the test requirements. Step S3.2: When applying the calibration controller, incremental PID mode is used. Based on the position deviation between the command and the turntable feedback within the current three control cycles, the control increment is calculated: in, The discrete control cycle of the turntable. Representing discrete time, for Time-based turntable command value, for Deviation between turntable commands and feedback at any time , and These are the proportional coefficient, integral coefficient, and derivative coefficient of the incremental PID controller; This yields the corrected turntable control command. This drives the turntable equipment to operate.

5. A user-end flight turntable dynamic response correction system based on model identification, characterized in that, include: Module M1: Select the test load identified by the flight turntable response model according to the specifications of the test product, compile the trigonometric function sweep frequency excitation signal, drive the turntable to run and collect commands and feedback data; Module M2: Analyzes turntable commands and feedback data, calculates amplitude and phase errors at each sweep frequency point, and identifies the turntable response model under test load given the turntable response model order. Module M3: Based on the turntable response model, design and optimize the parameters of the incremental PID controller, and connect the PID controller in series with the turntable forward control channel to compensate and correct the dynamic response of the turntable. In module M1: Module M1.1: The sweep frequency excitation signal uses a cosine function, and the position... ,speed and acceleration The formula is expressed as: in, For amplitude, For frequency, For time; Module M1.2: Design a constant acceleration mode, setting the acceleration amplitude of the cosine sweep frequency signal to the turntable's factory-set maximum acceleration. The preset ratio m of the indicator, combined with the maximum angular velocity Limitations are imposed, and the minimum allowable frequency is calculated. : Module M1.3: Starts frequency sweeping by rounding up from the minimum allowed frequency, continuing until it exceeds a frequency with a bandwidth of 20. Then it stops. At each frequency point, the cosine sweep signal runs at a constant speed to the peak position within the first preset time period, waits at the peak position within the second preset time period, starts the excitation after the preset time, and ends after running a preset number of complete cycles.

6. The user-end flight turntable dynamic response correction system based on model identification according to claim 5, characterized in that, In module M2: Module M2.1: Analyzes the acquired turntable commands and feedback data, and at each scanning frequency point, finds the amplitude and time of the command signal peak. , The amplitude and time of the trough , ; Find the amplitude and time of the feedback signal peak. , The amplitude and time of the trough , ; Module M2.2: Based on the amplitude and time of the peaks and troughs of the command and feedback signals, calculate the amplitude difference and phase difference at the scanning frequency points. The amplitude difference is calculated as follows: The phase difference is calculated as follows: 。 7. The user-end flight turntable dynamic response correction system based on model identification according to claim 6, characterized in that: By combining the amplitude and phase differences at various scanning frequencies, the turntable response transfer function is fitted using the invfreqs function in Matlab. in, To fit the coefficients of the numerator polynomial of the transfer function, To fit the coefficients of the denominator polynomial of the transfer function; and These are the orders of the numerator and denominator of the fitted transfer function, respectively. Angular velocity, It is an imaginary number.

8. The user-end flight turntable dynamic response correction system based on model identification according to claim 5, characterized in that, In module M3: Module M3.1: Based on the identified turntable response transfer function, design a series PID correction controller, and adjust the PID control coefficients in the discrete domain in combination with the turntable control step size until the turntable performance meets the test requirements; Module M3.2: When applying the calibration controller, incremental PID mode is used. Based on the position deviation between the command and the turntable feedback within the current three control cycles, the control increment is calculated. in, The discrete control cycle of the turntable. Representing discrete time, for Time-based turntable command value, for Deviation between turntable commands and feedback at any time , and These are the proportional coefficient, integral coefficient, and derivative coefficient of the incremental PID controller; This yields the corrected turntable control command. This drives the turntable equipment to operate.

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