A frequency response identification device and method for a rotary fuel metering device

Abstract

The application provides a rotating fuel metering device frequency response identification device and method. The device comprises a permanent magnet servo motor, an operation control unit, a resolver encoding and decoding module, a rotor position signal conditioning module, a power inverter unit, a motor phase current monitoring module, a coupling, a metering valve, a pressure measurement module, a rotating metering valve frequency response identification module, a rotating metering valve baud chart data statistical module and an upper computer module.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine control, and specifically relates to a frequency response identification device and method for a rotary fuel metering device. Background Technology

[0002] Fuel metering devices are critical components of aero-engine control systems, significantly impacting engine control performance and reliability. A precise control model for rotary fuel metering devices serves as the basis for designing digital electronic controllers (DECs) for aero-engines. While component-level models of fuel metering devices are readily available, the interconnectedness of multiple components after assembly makes a comprehensive model difficult to establish. This leads to the frequent use of trial-and-error methods and empirical parameter methods in DEC design, lacking a forward design basis in the frequency domain. Furthermore, fault location is particularly challenging after a control system failure, largely due to the lack of a control model for the fuel metering device. Summary of the Invention

[0003] This invention proposes a frequency response identification device and method for a rotary fuel metering device, which can solve the problem of difficulty in fault location after a control system failure.

[0004] In a first aspect, this application provides a frequency response identification device for a rotary fuel metering device, comprising: a permanent magnet servo motor, a computational control unit, a rotary transformer encoding / decoding module, a rotor position signal conditioning module, a power inverter unit, a motor phase current monitoring module, a coupling, a metering valve, a pressure measurement module, a rotary metering valve frequency response identification module, a rotary metering valve Bode plot data statistics module, and a host computer module, wherein: The permanent magnet servo motor is connected to the power inverter unit, rotor position signal conditioning module, motor phase current monitoring module, and coupling, respectively. The computing and control unit is connected to the host computer, rotary transformer encoding and decoding module, power inverter unit, motor phase current monitoring module, pressure measurement module, and rotary metering valve frequency response identification module, respectively. The rotary transformer encoding and decoding module is connected to the rotor position signal conditioning module and computing and control unit, respectively. The rotor position signal conditioning module is connected to the permanent magnet servo motor and rotary transformer encoding and decoding module, respectively. The power inverter unit is connected to the computing and control unit and permanent magnet servo motor, respectively. The motor phase current monitoring module is connected to the permanent magnet servo motor and computing and control unit, respectively. The coupling is connected to the permanent magnet servo motor and metering valve, respectively. The metering valve is connected to the coupling and pressure measurement module, respectively. The pressure measurement module is connected to the metering valve and computing and control unit, respectively. The rotary metering valve frequency response identification module is connected to the computing and control unit and rotary metering valve Bode plot data statistics module, respectively. The rotary metering valve Bode plot data statistics module is connected to the rotary metering valve frequency response identification module, respectively. The host computer module is connected to the computing and control unit.

[0005] Furthermore, the computing control unit includes a servo control algorithm module and a vector control module, which outputs a PWM signal, which is converted into a power signal by the power inverter unit and output to the motor windings; the vector control module is used to output a PWM signal based on the motor rotor position and motor phase current, in conjunction with the servo control algorithm module. The servo control algorithm module is used to complete the closed-loop control of the motor rotor position, speed, and current. The frequency response identification module of the rotary metering valve is used to identify the amplitude frequency response and phase frequency response of the fuel metering device through a frequency response identification algorithm, and generate amplitude gain and phase hysteresis data corresponding to each frequency point. The rotary metering valve Bode plot data statistics module is used to collect the amplitude gain and phase lag data generated by the rotary metering valve frequency response identification module, and convert them according to the amplitude and frequency representation units of the Bode plot, so that the frequency response data conforms to the display units of the Bode plot.

[0006] Furthermore, the permanent magnet servo motor is used to drive the rotary metering valve to move through the coupling under control, thereby realizing fuel flow regulation, and at the same time feeding back the motor phase current to the current sensor and the motor rotor position to the signal conditioning module. The rotary transformer encoding / decoding module is used to generate a rotary transformer excitation signal, output it to the rotor position signal conditioning module, receive the feedback signal output by the rotor position signal conditioning module, and calculate the motor rotor position based on the phase relationship between the excitation signal and the feedback signal. The rotor position signal conditioning module is used to receive the excitation signal from the rotary transformer encoding and decoding module, condition the signal and output it to the rotary transformer, and receive the feedback signal from the rotary transformer, condition it and output it to the rotary transformer encoding and decoding module. The power inverter unit is used to convert the control PWM signal output by the computing and control unit into a power PWM signal, thereby driving the permanent magnet servo motor to move. The motor phase current monitoring module is used to monitor the phase current of the three-phase windings of the motor and convert the current signal into a voltage signal suitable for microprocessor sampling. The coupling is used to connect the motor shaft and the metering valve shaft so that the two rotate synchronously; The metering valve is optional and driven by an electric motor to control fuel flow. The pressure measurement module is used to monitor the outlet pressure of the fuel metering device; The host computer module is used to interact with the computing and control unit, send motion commands to the device, and visualize the measurement results of the measuring device.

[0007] Furthermore, the vector control module includes a Clark transform module, a Park transform module, an inverse Park transform module, and an SVPWM vector calculation module, wherein: The Clark transformation module, based on the principle of amplitude equivalence, transforms the three-phase AC current into two-phase currents iα and iβ in a stationary coordinate system. The Park transformation integrates iα, iβ, and the motor rotor position θ to calculate the direct-axis current id and quadrature-axis current iq in the rotating coordinate system. The inverse Park transformation receives the direct-axis voltage Ud, quadrature-axis voltage Uq, and motor rotor position θ output by the servo control algorithm module, and converts the voltages in the two-phase rotating coordinate system into voltages Uα and Uβ in the two-phase stationary coordinate system. The SVPWM vector calculation module performs sector analysis, vector calculation, and correction based on Uα and Uβ, and outputs 6-channel PWM.

[0008] Furthermore, the servo control algorithm module includes: position control algorithm, speed control algorithm, direct-axis current id control algorithm, and quadrature-axis current iq control algorithm, wherein: The position control algorithm receives the position command sent by the host computer, calculates the deviation between the actual measured rotor position and the position command, and implements closed-loop control. The controller is Kp control. The position control algorithm outputs the speed command to the speed control algorithm. The speed control algorithm receives the speed command output by the position loop and the motor rotor position, calculates the actual speed after differentiation, and the deviation between the two calculations is used by the speed controller to implement closed-loop speed control. The speed controller is a PI controller, and the speed loop outputs the quadrature-axis current command iq. The quadrature axis current iq control algorithm receives the quadrature axis current command output by the speed loop and the iq current feedback output by the vector control module. The deviation between the two is calculated and closed-loop control is performed by the iq current controller, which outputs voltage uq to the vector control module. The iq current controller is a PI controller. The direct-axis current id control algorithm calculates the deviation between the id current command (0) and the iq current feedback output from the vector control module. The iq current controller performs closed-loop control and outputs voltage uq to the vector control module. The iq current controller is a PI controller.

[0009] Secondly, this application provides a frequency response identification method for a rotary fuel metering device, the method being applied to the aforementioned rotary fuel metering device frequency response identification device, the method comprising: Step 1: Confirm whether the device frequency response identification conditions are met. If the conditions are met, proceed with the frequency response identification plan. If the conditions are not met, check the identification conditions. Step 2: Determine the method for generating the motor rotor position for frequency response identification, the rotor position change pattern, and the motor rotor and the valve being directly connected with each other and in the same position. Step 3: During the execution of the frequency response identification plan, measure the amplitude of the rotor position at each frequency point, the amplitude of the outlet pressure, the ratio of the outlet pressure to the rotor position amplitude, the zero-phase position of the rotor position at each frequency point, the zero-phase position of the outlet pressure, and the hysteresis phase angle of the outlet pressure to the zero-phase position of the rotor position. Step 4: Calculate the amplitude ratio and phase difference of the outlet pressure to the rotor position at each frequency point to form amplitude-frequency characteristic and phase-frequency characteristic data.

[0010] Furthermore, step 1 includes: Step 11: Deploy the fuel metering device to the test bench. Connect the fuel booster pump to the front end of the metering device and connect the flow meter and fixed nozzle to the rear end of the metering device. Start the fuel booster pump and run it to the rated speed. Step 12: The host computer sends the initial position of the fuel metering device valve. The servo motor drives the valve to the initial position and monitors the regulator outlet pressure and fuel flow. When both pressure and fuel flow are zero, proceed to step 13. If the pressure and flow cannot return to zero, terminate the identification preparation and recheck the test conditions. Step 13: The host computer sends the middle position of the fuel metering device valve. The servo motor drives the valve to the middle position. The regulator outlet pressure and fuel flow are monitored. When the pressure and fuel flow are both within the small range of the middle position, proceed to step 14. If the pressure and flow cannot reach the expected position, the identification preparation is terminated and the test conditions are rechecked. Step 14: The host computer sends the maximum position of the fuel metering device valve. The servo motor drives the valve to the maximum position. The regulator outlet pressure and fuel flow are monitored. When the pressure and fuel flow are both within a small range of the maximum position, the identification preparation ends and the identification preparation completion flag is set, allowing the process to proceed to step 2. If the pressure and flow cannot reach the expected position, the identification preparation is terminated and the test conditions are rechecked.

[0011] Furthermore, step 2 includes: Step 21: The host computer sends the fuel metering device valve to the middle position. The servo motor drives the valve to the middle position. After the valve stabilizes in the middle position, proceed to step 22. Step 22: Using the middle position of the valve as the DC bias, add a starting frequency of 0.1Hz to the valve position command, with a step of 0.1Hz and a termination frequency of 80Hz. The amplitude is a sinusoidal disturbance of 5% of the valve's rated stroke. The device controls the motor to follow this position command, with each step frequency command lasting for 10 cycles.

[0012] Furthermore, step 3 includes: Step 31: Under the sinusoidal disturbance command, the metering valve fluctuates sinusoidally around the middle position, and the outlet pressure of the metering device will fluctuate sinusoidally. Step 32: Statistically calculate the bidirectional zero-crossing points of the motor rotor position and metering device outlet pressure at each frequency, and calculate the phase delay of pressure tracking rotor position accordingly; Statistically calculate the sinusoidal amplitude of valve position and outlet pressure, and calculate the amplitude ratio of metering device outlet pressure tracking rotor position accordingly. Step 33: With a statistical period of 50us, the rotor position statistically recorded in the current sampling period is θ(k), the rotor position in the next statistical period is θ(k+1), and the corresponding intermediate position before the disturbance is θ(0). Let Muti(θ) = (θ(k) - θ(0)) * (θ(k+1) - θ(0)); if Muti(θ) < 0, then the corresponding θ(k) is a zero-crossing point. Step 34: With a statistical period of 50us, let the outlet pressure of the current sampling period be P(k), the rotor position of the next statistical period be P(k+1), and the corresponding intermediate position before the disturbance be P(0). Let Muti(P) = (P(k) - P(0)) * (P(k+1) - P(0)). If Muti(P) < 0, then the corresponding P(k) is a zero crossing point. Step 35: Record the time when the motor rotor position crosses zero as t0. Taking t0 as the starting time, the number of zero-crossing difference cycles N=0. Start searching for the first zero-crossing time of the metering device outlet pressure, denoted as t1. Perform N+1 operations in each sampling cycle. The sampling cycle is 50us. At time t1, t1-t0=N*0.00005s. Let k=N, then the time difference between the zero-crossing point of a single rotor position and the zero-crossing point of the outlet pressure is k*0.00005s. Step 36: Each frequency point lasts for 10 cycles, for a total of 20 zero-crossing points. The time differences of the 20 zero-crossing points are weighted and averaged to obtain the average zero-crossing time difference as kave*0.00005s. Step 37: Let the frequency of the current sinusoidal disturbance be f(k). The phase lag angle corresponding to this frequency point is calculated as follows: θlag(k) = kave * 0.00005 * f(k) * 360. Step 38: Let θ(k) be the zero-crossing point of the valve position. Starting from this zero-crossing point, traverse the point with the maximum amplitude of the valve position within (1 / f(k)) / 0.00005 sampling periods, and denot it as θmax(k). Take the weighted average of θmax(k) over 10 sampling periods to obtain θmaxave(k). Step 39: Let P(k) be the zero point of the outlet pressure of the metering device. Starting from this zero point, within (1 / f(k)) / 0.00005 sampling periods, traverse the point with the maximum amplitude of the outlet pressure of the metering device, and denote it as Pmax(k). Take the weighted average of Pmax(k) of 10 sampling periods to obtain Pmaxave(k). Step 310: Record the sinusoidal amplitude of the metering device outlet pressure corresponding to each traversal frequency point f(k) as Pmaxave(k) and the sinusoidal amplitude of the motor rotor position as θmaxave(k); then the gain K(k) corresponding to this frequency point is Pmaxave(k) / θmaxave(k).

[0013] Furthermore, step 4 includes: Step 41: Record the amplitude ratio K(k) and phase difference θlag(k) corresponding to each frequency point f(k). Compress the frequency coordinates according to the logarithmic representation method of frequency points in the Bode plot and save the data. Step 42: Draw the Bode plot amplitude-frequency response and phase-frequency response diagrams based on the Bode plot data.

[0014] In summary, a frequency response identification device and method for a rotary fuel metering device provides a basis for constructing the transfer function of the metering device by identifying its amplitude-frequency and phase-frequency characteristics; it also provides a basis for the design of metering device control algorithms, fault diagnosis, and health management; and it lays the foundation for the safe and reliable control of aero-engine operation. Attached Figure Description

[0015] Figure 1 A schematic diagram of the structure of a frequency response identification device for a rotary fuel metering device provided in this application; Figure 2 A schematic diagram of a rotary transformer excitation signal conditioner provided in this application; Figure 3 A schematic diagram of a rotary transformer output signal conditioner structure provided in this application; Figure 4 A schematic diagram of a power inverter unit provided in this application; Figure 5 A schematic diagram of a vector control module provided in this application; Figure 6 A schematic diagram of a servo control algorithm module provided in this application; Figure 7 A schematic diagram of a pressure measurement module provided in this application; Figure 8 This is a schematic diagram of a frequency response identification module for a rotary metering valve provided in this application. Detailed Implementation

[0016] Example 1 like Figure 1 As shown, this application provides a frequency response identification device for a rotary fuel metering device. The rotary fuel metering device frequency response identification device includes: a permanent magnet servo motor, a computational control unit, a rotary transformer encoding / decoding module, a rotor position signal conditioning module, a power inverter unit, a motor phase current monitoring module, a coupling, a metering valve, a pressure measurement module, a rotary metering valve frequency response identification module, a rotary metering valve Bode plot data statistics module, and a host computer module, wherein: The permanent magnet servo motor is connected to the power inverter unit, rotor position signal conditioning module, motor phase current monitoring module, and coupling, respectively. The computing and control unit is connected to the host computer, rotary transformer encoding and decoding module, power inverter unit, motor phase current monitoring module, pressure measurement module, and rotary metering valve frequency response identification module, respectively. The rotary transformer encoding and decoding module is connected to the rotor position signal conditioning module and computing and control unit, respectively. The rotor position signal conditioning module is connected to the permanent magnet servo motor and rotary transformer encoding and decoding module, respectively. The power inverter unit is connected to the computing and control unit and permanent magnet servo motor, respectively. The motor phase current monitoring module is connected to the permanent magnet servo motor and computing and control unit, respectively. The coupling is connected to the permanent magnet servo motor and metering valve, respectively. The metering valve is connected to the coupling and pressure measurement module, respectively. The pressure measurement module is connected to the metering valve and computing and control unit, respectively. The rotary metering valve frequency response identification module is connected to the computing and control unit and rotary metering valve Bode plot data statistics module, respectively. The rotary metering valve Bode plot data statistics module is connected to the rotary metering valve frequency response identification module, respectively. The host computer module is connected to the computing and control unit.

[0017] The permanent magnet servo motor is used to drive the rotary metering valve to move through the coupling under control to achieve fuel flow regulation. At the same time, it feeds back the motor phase current to the current sensor and the motor rotor position to the signal conditioning module. The computing and control unit is the core of the device's computing and control, including a servo control algorithm module and a vector control module. It outputs PWM signals, which are converted into power signals by the power inverter unit and output to the motor windings. The rotary transformer encoding / decoding module is used to generate a rotary transformer excitation signal, output it to the rotor position signal conditioning module, receive the feedback signal output by the rotor position signal conditioning module, and calculate the motor rotor position based on the phase relationship between the excitation signal and the feedback signal. The rotor position signal conditioning module is used to receive the excitation signal from the rotary transformer encoding and decoding module, condition the signal and output it to the rotary transformer, and receive the feedback signal from the rotary transformer, condition it and output it to the rotary transformer encoding and decoding module. The power inverter unit is used to convert the control PWM signal output by the computing and control unit into a power PWM signal, thereby driving the permanent magnet servo motor to move. The motor phase current monitoring module is used to monitor the phase current of the three-phase windings of the motor and convert the current signal into a voltage signal suitable for microprocessor sampling. The vector control module is used to output a PWM signal based on the motor rotor position and motor phase current, combined with the servo control algorithm module. The servo control algorithm module is used to complete the closed-loop control of the motor rotor position, speed, and current. The coupling is used to connect the motor shaft and the metering valve shaft so that the two rotate synchronously; The metering valve is optional and driven by an electric motor to control fuel flow. The pressure measurement module is used to monitor the outlet pressure of the fuel metering device; The frequency response identification module of the rotary metering valve is used to identify the amplitude frequency response and phase frequency response of the fuel metering device through a frequency response identification algorithm, and generate amplitude gain and phase hysteresis data corresponding to each frequency point. The rotary metering valve Bode plot data statistics module is used to collect the amplitude gain and phase hysteresis data generated by the rotary metering valve frequency response identification module, and convert them according to the amplitude and frequency representation units of the Bode plot, so that the frequency response data conforms to the display units of the Bode plot. The host computer module is used to interact with the computing and control unit, send motion commands to the device, and visualize the measurement results of the measuring device.

[0018] Specifically, when the test device is in operation, it is deployed on a ground platform, and the system is pressurized by a fuel pump to provide the fuel pressure and hydraulic power required for the rotary fuel metering device to operate.

[0019] Specifically, the permanent magnet servo motor includes three-phase windings A, B, and C, and integrates a rotary transformer for rotor position measurement. The rotor of the rotary transformer is coaxial with the motor rotor, and the zero point of the rotary transformer is aligned with the zero-crossing point of the opposite electromotive force of motor A. It should be noted that the permanent magnet servo motor is installed with fixed fixtures to ensure reliable support of the motor. Furthermore, the motor shaft is concentric with the valve shaft. After the motor and the metering valve are connected by a coupling, the motor is almost unaffected by radial force during operation.

[0020] Specifically, the arithmetic control unit is the core of the arithmetic control of the measuring device, which includes a high-speed AD converter, an arithmetic control unit, a logic unit, a data storage unit, and a program storage unit; The computation control unit monitors the motor rotor position in real time and receives angle servo commands from the host computer. It transmits the angle commands and electronic rotor position to the servo control algorithm module. The servo algorithm module and the vector control module cooperate to realize angle servoing. The vector control module outputs the PWM duty cycle command to the computation control unit, which controls the six-channel complementary duty cycle output.

[0021] Specifically, the rotary transformer encoding / decoding module generates a sinusoidal excitation signal; receives sinusoidal differential and cosine differential signals output by the rotor position signal conditioning module; calculates the rotor position using its internal position calculation algorithm; and outputs the calculation result to the arithmetic control unit via a parallel bus.

[0022] The rotary transformer encoding / decoding module generates a sinusoidal excitation signal with an output frequency of 10kHz, an amplitude of 2V, and a DC bias of 2.5V; the rotor position signal conditioning module outputs sinusoidal differential and cosine differential signals with a DC bias of 2.5V and a peak value of 3.2V.

[0023] Specifically, the rotor position signal conditioning module includes: a rotary transformer excitation signal conditioner and a rotary transformer output signal conditioner; like Figure 2 As shown in the figure below, the structure of the rotary transformer excitation signal conditioner is to amplify the sinusoidal signal output by the rotary transformer encoding and decoding module with high bandwidth power. The rotary transformer excitation signal conditioner consists of an active filter bias circuit and a voltage amplifier circuit connected in series.

[0024] In practical applications, the sinusoidal signal is amplified with high bandwidth power, so that the peak-to-peak value of the output is amplified to 12V.

[0025] The active filter bias circuit superimposes a 2V sinusoidal signal output from the rotary transformer excitation signal generator with a 2.5V DC bias signal, and then performs a second-order active Chebyshev filter on the signal. The filter parameters are adjusted by resistors and capacitors, the filter stopband attenuation is configured to -20dB, and the cutoff frequency is configured to 18KHz.

[0026] like Figure 3 As shown in the figure below, the structure of the resolver output signal conditioner consists of an electrostatic discharge (ESD) protector, an active filter, and a signal amplifier connected in series. The ESD protector is used to prevent damage to the subsequent circuitry caused by static electricity from the human body during the insertion and removal of the resolver's electrical connector. The active filter is a second-order active Chebyshev filter with DC bias function, and its parameter configuration is consistent with that of the excitation signal conditioner. The signal amplifier is used to condition the signal output from the resolver into sinusoidal differential and cosine differential signals.

[0027] The signal amplifier is used to condition the 2.6V peak signal output from the rotary transformer into a 3.2V peak sinusoidal differential and cosine differential signal.

[0028] Specifically, such as Figure 4 As shown, the power inverter unit includes a gate driver and a power inverter unit connected in sequence; The gate driver receives the TTL signal output by the operational control unit and converts it into a signal that requires the voltage, for example 15V, for each MOS transistor in the power inverter unit to operate, and has a strong drive current. The power inverter unit receives the control signal from the gate driver and, under the control of the gate driver, realizes the switching of the MOS transistor; the gate driver and the power inverter unit work together to realize the conversion of TTL signal to power signal.

[0029] Specifically, the motor phase current monitoring module includes: a Hall current sensor, a signal conditioner, and a current measuring device connected in sequence.

[0030] The primary terminal of the Hall current sensor is connected in series in each phase line of the motor. When the motor phase current flows through the Hall sensor, the secondary terminal of the sensor will sense the corresponding voltage, realizing the I / V conversion from current to voltage. The signal conditioner is a voltage follower connected in series with an RC low-pass filter. The voltage signal output by the current sensor is connected to the non-inverting input of the follower, the inverting input of the follower is connected to the output, and the output of the follower is connected to the RC filter. The filter bandwidth is set to 40kHz.

[0031] The current measuring device samples the voltage value after RC filtering, and combines the correspondence between the current and output voltage of the Hall current sensor to calculate the motor phase current in reverse from the voltage value.

[0032] The current measuring device samples periodically at a frequency of 10 kHz.

[0033] Specifically, such as Figure 5 As shown, the vector control module includes a Clark transform module, a Park transform module, an inverse Park transform module, and an SVPWM vector calculation module; The Clark transformation module, based on the principle of amplitude equivalence, transforms the three-phase AC current into two-phase currents iα and iβ in a stationary coordinate system. The Park transformation integrates iα, iβ, and the motor rotor position θ to calculate the direct-axis current id and quadrature-axis current iq in the rotating coordinate system. The inverse Park transformation receives the direct-axis voltage Ud, quadrature-axis voltage Uq, and motor rotor position θ output by the servo control algorithm module, and converts the voltages in the two-phase rotating coordinate system into voltages Uα and Uβ in the two-phase stationary coordinate system. The SVPWM vector calculation module performs sector analysis, vector calculation, and correction based on Uα and Uβ, and outputs 6-channel PWM.

[0034] Specifically, such as Figure 6 As shown, the servo control algorithm module includes: position control algorithm, speed control algorithm, direct axis current id control algorithm, and quadrature axis current iq control algorithm; The position control algorithm receives the position command sent by the host computer, calculates the deviation between the actual measured rotor position and the position command, and implements closed-loop control. The controller is Kp control. The position control algorithm outputs the speed command to the speed control algorithm. The speed control algorithm receives the speed command output by the position loop and the motor rotor position, calculates the actual speed after differentiation, and the deviation between the two calculations is used by the speed controller to implement closed-loop speed control. The speed controller is a PI controller, and the speed loop outputs the quadrature-axis current command iq. The quadrature axis current iq control algorithm receives the quadrature axis current command output by the speed loop and the iq current feedback output by the vector control module. The deviation between the two is calculated and closed-loop control is performed by the iq current controller, which outputs voltage uq to the vector control module. The iq current controller is a PI controller. The direct-axis current id control algorithm calculates the deviation between the id current command (0) and the iq current feedback output by the vector control module. The iq current controller performs closed-loop control and outputs voltage uq to the vector control module. The iq current controller is a PI controller. Specifically, such as Figure 7 As shown, the pressure measurement module includes: sensor excitation signal, piezoresistive pressure sensor, sensor feedback signal conditioning, and pressure monitoring. The signal excitation source generates the current required for the pressure sensor to operate, such as a constant current of 10mA. It consists of a voltage reference module and a voltage-controlled constant current source. The voltage-controlled constant current source receives the voltage input from the voltage reference module and generates a 10mA current. The voltage value corresponding to the 10mA constant current is determined by the characteristics of the voltage-controlled constant current source itself. The voltage reference module is a high-precision reference source with feedback adjustment.

[0035] The pressure sensor receives a 10mA current excitation source and feeds back a 0~75mV voltage signal, corresponding to a fuel pressure of 0~5MPa. The sensor signal conditioning receives 0~75mV from the pressure sensor output, amplifies the signal to 0~3V through an integrating operational amplifier with a magnification factor of 40, and adjusts the integration time constant through capacitor C1. The time constant is determined based on the signal noise level. The pressure monitoring receives a 0~3V voltage signal from the signal conditioning output, performs high-speed AD conversion at a sampling frequency of 100us, and converts the AD conversion result into a physical pressure value by combining the correspondence between voltage and fuel pressure. Specifically, such as Figure 8 As shown, the frequency response identification module of the rotary metering valve includes: frequency response identification preparation, frequency response identification plan, frequency response identification implementation, and frequency response result statistics.

[0036] The frequency response identification preparation method is as follows: deploy the fuel metering device on the test bench, connect the fuel booster pump to the front end of the metering device, connect the flow meter and fixed nozzle to the rear end of the metering device, start the fuel booster pump and run it to the rated speed. The host computer sends the initial position of the fuel metering device valve, and the servo motor drives the valve to the initial position. The regulator outlet pressure and fuel flow are monitored. When both pressure and fuel flow are zero, the next stage begins. If the pressure and flow cannot return to zero, the identification preparation is terminated and the test conditions are rechecked. The host computer sends the fuel metering device valve to the middle position. The servo motor drives the valve to the middle position and monitors the regulator outlet pressure and fuel flow. When the pressure and fuel flow are both within the small range of the middle position, the next stage begins. If the pressure and flow cannot reach the expected position, the identification preparation is terminated and the test conditions are rechecked. The host computer sends the maximum position of the fuel metering device valve. The servo motor drives the valve to the maximum position and monitors the regulator outlet pressure and fuel flow. When both the pressure and fuel flow are within a small range of the maximum position, the identification preparation ends and the identification preparation completion flag is set. If the pressure and flow cannot reach the expected position, the identification preparation is terminated and the test conditions are rechecked. The frequency response identification plan is as follows: the host computer sends the middle position of the fuel metering device valve, the servo motor drives the valve to the middle position, and after the valve stabilizes at the middle position, the frequency response identification program is entered. With the valve's center position as the DC bias, a starting frequency of 0.1Hz is superimposed on the valve position command, with a step of 0.1Hz and a termination frequency of 80Hz. The amplitude is a sinusoidal disturbance of 5% of the valve's rated stroke. The device controls the motor to follow this position command, with each step frequency command lasting for 10 cycles. Under the sinusoidal disturbance command, the metering valve fluctuates sinusoidally around the middle position, and the outlet pressure of the metering device will fluctuate sinusoidally. The phase delay of pressure tracking of rotor position is calculated by statistically analyzing the bidirectional zero-crossing points of motor rotor position and metering device outlet pressure at each frequency. The amplitude ratio of metering device outlet pressure tracking of rotor position is calculated by statistically analyzing valve position sine amplitude and outlet pressure sine amplitude.

[0037] The method for statistically analyzing the bidirectional zero-crossing point of the motor rotor position is as follows: with a statistical period of 50µs, the rotor position statistically analyzed in the current sampling period is θ(k), the rotor position in the next statistical period is θ(k+1), and the corresponding intermediate position before the disturbance is θ(0). Muti(θ) = (θ(k) - θ(0)) * (θ(k+1) - θ(0)); if Muti(θ) < 0, then the corresponding θ(k) is a zero-crossing point. The bidirectional zero-crossing statistical method for the outlet pressure of the metering device is as follows: with a statistical period of 50µs, the outlet pressure statistically recorded in the current sampling period is P(k), the rotor position in the next statistical period is P(k+1), and the corresponding intermediate position before the disturbance is P(0). Muti(P) = (P(k) - P(0)) * (P(k+1) - P(0)); if Muti(P) < 0, then the corresponding P(k) is the zero-crossing point. The method for measuring the phase delay of the outlet pressure in tracking the rotor position is as follows: Let t0 be the moment the motor rotor position crosses zero. Starting from t0, with a zero-crossing difference period of N=0, begin searching for the first zero-crossing moment of the metering device's outlet pressure, denoted as t1. Perform N+1 operations per sampling period, with a sampling period of 50µs. At time t1, t1-t0=N*0.00005s. Let k=N, then the time difference between a single rotor position zero-crossing point and the outlet pressure zero-crossing point is k*0.00005s. Each frequency point lasts for 10 cycles, for a total of 20 zero-crossing points. The time differences of the 20 zero-crossing points are weighted and averaged to obtain the average zero-crossing time difference as kave*0.00005s. Let the frequency of the current sinusoidal disturbance be f(k). Then the phase lag angle corresponding to this frequency point is calculated as follows: θlag(k) = kave * 0.00005 * f(k) * 360. The method for measuring the sinusoidal amplitude of the valve position is as follows: θ(k) is the zero-crossing point of the valve position. Taking this zero-crossing point as the starting time, the maximum amplitude point of the valve position is traversed within (1 / f(k)) / 0.00005 sampling periods and denoted as θmax(k). The weighted average of θmax(k) over 10 sampling periods is obtained as θmaxave(k). The method for measuring the sinusoidal amplitude of the outlet pressure of the metering device is as follows: Let P(k) be the zero point of the outlet pressure of the metering device. Taking this zero point as the starting time, within (1 / f(k)) / 0.00005 sampling periods, traverse the point with the maximum amplitude of the outlet pressure of the metering device, and record it as Pmax(k). The weighted average of Pmax(k) of 10 sampling periods is obtained as Pmaxave(k). The method for calculating the amplitude ratio of the metering device outlet pressure to the rotor position tracking is as follows: Let the sinusoidal amplitude of the metering device outlet pressure corresponding to each traversal frequency point f(k) be Pmaxave(k), and the sinusoidal amplitude of the motor rotor position be θmaxave(k); then the amplitude ratio gain K(k) corresponding to this frequency point = Pmaxave(k) / θmaxave(k); The frequency response results are statistically analyzed as follows: record the amplitude ratio K(k) and phase difference θlag(k) corresponding to each frequency point f(k), compress the frequency coordinates according to the logarithmic representation method of frequency points in the Bode plot, save the data, and facilitate the plotting of Bode plot amplitude-frequency characteristics and phase-frequency characteristics.

[0038] Example 2 This application provides a frequency response identification method for a rotary fuel metering device, implemented using the frequency response identification device for a rotary fuel metering device provided in the above embodiments. The method includes: Step 1: Frequency response identification preparation.

[0039] Specifically, step 1 includes: Step 11: Deploy the fuel metering device to the test bench. Connect the fuel booster pump to the front end of the metering device and connect the flow meter and fixed nozzle to the rear end of the metering device. Start the fuel booster pump and run it to the rated speed. Step 12: The host computer sends the initial position of the fuel metering device valve. The servo motor drives the valve to the initial position and monitors the regulator outlet pressure and fuel flow. When both pressure and fuel flow are zero, proceed to step 13. If the pressure and flow cannot return to zero, terminate the identification preparation and recheck the test conditions. Step 13: The host computer sends the middle position of the fuel metering device valve. The servo motor drives the valve to the middle position. The regulator outlet pressure and fuel flow are monitored. When the pressure and fuel flow are both within the small range of the middle position, proceed to step 14. If the pressure and flow cannot reach the expected position, the identification preparation is terminated and the test conditions are rechecked. Step 14: The host computer sends the maximum position of the fuel metering device valve. The servo motor drives the valve to the maximum position. The regulator outlet pressure and fuel flow are monitored. When the pressure and fuel flow are both within a small range of the maximum position, the identification preparation ends and the identification preparation completion flag is set, allowing the process to proceed to step 2. If the pressure and flow cannot reach the expected position, the identification preparation is terminated and the test conditions are rechecked.

[0040] Step 2: Frequency Response Identification Plan. Specifically, this includes the following steps: Step 21: The host computer sends the fuel metering device valve to the middle position. The servo motor drives the valve to the middle position. After the valve stabilizes in the middle position, proceed to step 22. Step 22: Using the middle position of the valve as the DC bias, add 0.1Hz as the starting frequency to the valve position command, step by 0.1Hz, and 80Hz as the ending frequency. The amplitude is a sinusoidal disturbance of 5% of the valve's rated stroke. The device controls the motor to follow this position command. Each step frequency command lasts for 10 cycles. Step 3: Frequency Response Identification Process. Specifically, this includes the following steps: Step 31: Under the sinusoidal disturbance command, the metering valve fluctuates sinusoidally around the middle position, and the outlet pressure of the metering device will fluctuate sinusoidally. Step 32: Statistically calculate the bidirectional zero-crossing points of the motor rotor position and metering device outlet pressure at each frequency, and calculate the phase delay of pressure tracking rotor position accordingly; Statistically calculate the sinusoidal amplitude of valve position and outlet pressure, and calculate the amplitude ratio of metering device outlet pressure tracking rotor position accordingly.

[0041] Step 33: With a statistical period of 50us, the rotor position statistically recorded in the current sampling period is θ(k), the rotor position in the next statistical period is θ(k+1), and the corresponding intermediate position before the disturbance is θ(0). Let Muti(θ) = (θ(k) - θ(0)) * (θ(k+1) - θ(0)); if Muti(θ) < 0, then the corresponding θ(k) is a zero-crossing point. Step 34: With a statistical period of 50us, let the outlet pressure of the current sampling period be P(k), the rotor position of the next statistical period be P(k+1), and the corresponding intermediate position before the disturbance be P(0). Let Muti(P) = (P(k) - P(0)) * (P(k+1) - P(0)). If Muti(P) < 0, then the corresponding P(k) is a zero crossing point. Step 35: Record the time when the motor rotor position crosses zero as t0. Taking t0 as the starting time, the number of zero-crossing difference cycles N=0. Start searching for the first zero-crossing time of the metering device outlet pressure, denoted as t1. Perform N+1 operations in each sampling cycle. The sampling cycle is 50us. At time t1, t1-t0=N*0.00005s. Let k=N, then the time difference between the zero-crossing point of a single rotor position and the zero-crossing point of the outlet pressure is k*0.00005s. Step 36: Each frequency point lasts for 10 cycles, for a total of 20 zero-crossing points. The time differences of the 20 zero-crossing points are weighted and averaged to obtain the average zero-crossing time difference as kave*0.00005s. Step 37: Let the frequency of the current sinusoidal disturbance be f(k). The phase lag angle corresponding to this frequency point is calculated as follows: θlag(k) = kave * 0.00005 * f(k) * 360. Step 38: Let θ(k) be the zero-crossing point of the valve position. Starting from this zero-crossing point, traverse the point with the maximum amplitude of the valve position within (1 / f(k)) / 0.00005 sampling periods, and denot it as θmax(k). Take the weighted average of θmax(k) over 10 sampling periods to obtain θmaxave(k). Step 39: Let P(k) be the zero point of the outlet pressure of the metering device. Starting from this zero point, within (1 / f(k)) / 0.00005 sampling periods, traverse the point with the maximum amplitude of the outlet pressure of the metering device, and denote it as Pmax(k). Take the weighted average of Pmax(k) of 10 sampling periods to obtain Pmaxave(k). Step 310: Record the sinusoidal amplitude of the metering device outlet pressure corresponding to each traversal frequency point f(k) as Pmaxave(k) and the sinusoidal amplitude of the motor rotor position as θmaxave(k); then the gain K(k) corresponding to this frequency point is Pmaxave(k) / θmaxave(k); Step 4: Frequency response results statistics. Specifically, this includes the following steps: Step 41: Record the amplitude ratio K(k) and phase difference θlag(k) corresponding to each frequency point f(k). Compress the frequency coordinates according to the logarithmic representation method of frequency points in the Bode plot and save the data. Step 42: Draw the Bode plot amplitude-frequency response and phase-frequency response diagrams based on the Bode plot data.

[0042] In summary, in view of the defects and deficiencies in the above-mentioned background technology, the purpose of this invention is to propose a frequency response identification device for a rotary fuel metering device. By identifying the amplitude-frequency characteristics and phase-frequency characteristics, the overall transfer function of the metering device can be further constructed, which serves as the basis for the design of the electronic controller, as well as the basis for fault diagnosis, health management and design optimization of the fuel metering device, thus laying the foundation for improving the control performance and operational safety of aero-engines.

[0043] This invention is primarily used in aero-engine control systems. Its main function is to address the lack of a control model for rotary fuel metering devices by designing a frequency response identification device for these devices. This provides a reference for the design and analysis of fuel metering device control algorithms, facilitating algorithm optimization; it also serves as a basis for fault diagnosis and health management of the metering device; and it lays the foundation for improving the control performance and operational safety of aero-engines.

Claims

1. A frequency response identification device for a rotary fuel metering device, characterized in that, include: The system includes a permanent magnet servo motor, a computation and control unit, a rotary transformer encoding / decoding module, a rotor position signal conditioning module, a power inverter unit, a motor phase current monitoring module, a coupling, a metering valve, a pressure measurement module, a rotary metering valve frequency response identification module, a rotary metering valve Bode plot data statistics module, and a host computer module. The permanent magnet servo motor is connected to the power inverter unit, rotor position signal conditioning module, motor phase current monitoring module, and coupling, respectively. The computing and control unit is connected to the host computer, rotary transformer encoding and decoding module, power inverter unit, motor phase current monitoring module, pressure measurement module, and rotary metering valve frequency response identification module, respectively. The rotary transformer encoding and decoding module is connected to the rotor position signal conditioning module and computing and control unit, respectively. The rotor position signal conditioning module is connected to the permanent magnet servo motor and rotary transformer encoding and decoding module, respectively. The power inverter unit is connected to the computing and control unit and permanent magnet servo motor, respectively. The motor phase current monitoring module is connected to the permanent magnet servo motor and computing and control unit, respectively. The coupling is connected to the permanent magnet servo motor and metering valve, respectively. The metering valve is connected to the coupling and pressure measurement module, respectively. The pressure measurement module is connected to the metering valve and computing and control unit, respectively. The rotary metering valve frequency response identification module is connected to the computing and control unit and the rotary metering valve Bode plot data statistics module, respectively. The rotary metering valve Bode plot data statistics module is connected to the rotary metering valve frequency response identification module, respectively. The host computer module is connected to the computing and control unit.

2. The apparatus according to claim 1, characterized in that, The computing and control unit includes a servo control algorithm module and a vector control module. It outputs a PWM signal, which is converted into a power signal by the power inverter unit and output to the motor winding. The vector control module is used to output a PWM signal based on the motor rotor position and motor phase current, in conjunction with the servo control algorithm module. The servo control algorithm module is used to complete the closed-loop control of the motor rotor position, speed, and current. The frequency response identification module of the rotary metering valve is used to identify the amplitude frequency response and phase frequency response of the fuel metering device through a frequency response identification algorithm, and generate amplitude gain and phase hysteresis data corresponding to each frequency point. The rotary metering valve Bode plot data statistics module is used to collect the amplitude gain and phase lag data generated by the rotary metering valve frequency response identification module, and convert them according to the amplitude and frequency representation units of the Bode plot, so that the frequency response data conforms to the display units of the Bode plot.

3. The apparatus according to claim 1, characterized in that, The permanent magnet servo motor is used to drive the rotary metering valve to move through the coupling under control to achieve fuel flow regulation. At the same time, it feeds back the motor phase current to the current sensor and the motor rotor position to the signal conditioning module. The rotary transformer encoding / decoding module is used to generate a rotary transformer excitation signal, output it to the rotor position signal conditioning module, receive the feedback signal output by the rotor position signal conditioning module, and calculate the motor rotor position based on the phase relationship between the excitation signal and the feedback signal. The rotor position signal conditioning module is used to receive the excitation signal from the rotary transformer encoding and decoding module, condition the signal and output it to the rotary transformer, and receive the feedback signal from the rotary transformer, condition it and output it to the rotary transformer encoding and decoding module. The power inverter unit is used to convert the control PWM signal output by the computing and control unit into a power PWM signal, thereby driving the permanent magnet servo motor to move. The motor phase current monitoring module is used to monitor the phase current of the three-phase windings of the motor and convert the current signal into a voltage signal suitable for microprocessor sampling. The coupling is used to connect the motor shaft and the metering valve shaft so that the two rotate synchronously; The metering valve is optional and driven by an electric motor to control fuel flow. The pressure measurement module is used to monitor the outlet pressure of the fuel metering device; The host computer module is used to interact with the computing and control unit, send motion commands to the device, and visualize the measurement results of the measuring device.

4. The apparatus according to claim 2, characterized in that, The vector control module includes a Clark transform module, a Park transform module, an inverse Park transform module, and an SVPWM vector calculation module, among which: The Clark transformation module, based on the principle of amplitude equivalence, transforms the three-phase AC current into two-phase currents iα and iβ in a stationary coordinate system. The Park transformation integrates iα, iβ, and the motor rotor position θ to calculate the direct-axis current id and quadrature-axis current iq in the rotating coordinate system. The inverse Park transformation receives the direct-axis voltage Ud, quadrature-axis voltage Uq, and motor rotor position θ output by the servo control algorithm module, and converts the voltages in the two-phase rotating coordinate system into voltages Uα and Uβ in the two-phase stationary coordinate system. The SVPWM vector calculation module performs sector analysis, vector calculation, and correction based on Uα and Uβ, and outputs 6-channel PWM.

5. The apparatus according to claim 2, characterized in that, The servo control algorithm module includes: position control algorithm, speed control algorithm, direct-axis current (id) control algorithm, and quadrature-axis current (iq) control algorithm, among which: The position control algorithm receives the position command sent by the host computer, calculates the deviation between the actual measured rotor position and the position command, and implements closed-loop control. The controller is Kp control. The position control algorithm outputs the speed command to the speed control algorithm. The speed control algorithm receives the speed command output by the position loop and the motor rotor position, calculates the actual speed after differentiation, and the deviation between the two calculations is used by the speed controller to implement closed-loop speed control. The speed controller is a PI controller, and the speed loop outputs the quadrature-axis current command iq. The quadrature axis current iq control algorithm receives the quadrature axis current command output by the speed loop and the iq current feedback output by the vector control module. The deviation between the two is calculated and closed-loop control is performed by the iq current controller, which outputs voltage uq to the vector control module. The iq current controller is a PI controller. The direct-axis current id control algorithm calculates the deviation between the id current command (0) and the iq current feedback output from the vector control module. The iq current controller performs closed-loop control and outputs voltage uq to the vector control module. The iq current controller is a PI controller.

6. A method for frequency response identification of a rotary fuel metering device, characterized in that, The method is applied to the frequency response identification device of the rotary fuel metering device according to claims 1-5, and the method includes: Step 1: Confirm whether the device frequency response identification conditions are met. If the conditions are met, proceed with the frequency response identification plan. If the conditions are not met, check the identification conditions. Step 2: Determine the method for generating the motor rotor position for frequency response identification, the rotor position change pattern, and the motor rotor and the valve being directly connected with each other and in the same position. Step 3: During the execution of the frequency response identification plan, measure the amplitude of the rotor position at each frequency point, the amplitude of the outlet pressure, the ratio of the outlet pressure to the rotor position amplitude, the zero-phase position of the rotor position at each frequency point, the zero-phase position of the outlet pressure, and the hysteresis phase angle of the outlet pressure to the zero-phase position of the rotor position. Step 4: Calculate the amplitude ratio and phase difference of the outlet pressure to the rotor position at each frequency point to form amplitude-frequency characteristic and phase-frequency characteristic data.

7. The method according to claim 6, characterized in that, Step 1 includes: Step 11: Deploy the fuel metering device to the test bench. Connect the fuel booster pump to the front end of the metering device and connect the flow meter and fixed nozzle to the rear end of the metering device. Start the fuel booster pump and run it to the rated speed. Step 12: The host computer sends the initial position of the fuel metering device valve. The servo motor drives the valve to the initial position and monitors the regulator outlet pressure and fuel flow. When both pressure and fuel flow are zero, proceed to step 13. If the pressure and flow cannot return to zero, terminate the identification preparation and recheck the test conditions. Step 13: The host computer sends the middle position of the fuel metering device valve. The servo motor drives the valve to the middle position. The regulator outlet pressure and fuel flow are monitored. When the pressure and fuel flow are both within the small range of the middle position, proceed to step 14. If the pressure and flow cannot reach the expected position, the identification preparation is terminated and the test conditions are rechecked. Step 14: The host computer sends the maximum position of the fuel metering device valve. The servo motor drives the valve to the maximum position. The regulator outlet pressure and fuel flow are monitored. When the pressure and fuel flow are both within a small range of the maximum position, the identification preparation ends and the identification preparation completion flag is set, allowing the process to proceed to step 2. If the pressure and flow cannot reach the expected position, the identification preparation is terminated and the test conditions are rechecked.

8. The method according to claim 6, characterized in that, Step 2 includes: Step 21: The host computer sends the fuel metering device valve to the middle position. The servo motor drives the valve to the middle position. After the valve stabilizes in the middle position, proceed to step 22. Step 22: Using the middle position of the valve as the DC bias, add a starting frequency of 0.1Hz to the valve position command, with a step of 0.1Hz and a termination frequency of 80Hz. The amplitude is a sinusoidal disturbance of 5% of the valve's rated stroke. The device controls the motor to follow this position command, with each step frequency command lasting for 10 cycles.

9. The method according to claim 6, characterized in that, Step 3 includes: Step 31: Under the sinusoidal disturbance command, the metering valve fluctuates sinusoidally around the middle position, and the outlet pressure of the metering device will fluctuate sinusoidally. Step 32: Statistically calculate the bidirectional zero-crossing points of the motor rotor position and metering device outlet pressure at each frequency, and calculate the phase delay of pressure tracking rotor position accordingly; Statistically calculate the sinusoidal amplitude of valve position and outlet pressure, and calculate the amplitude ratio of metering device outlet pressure tracking rotor position accordingly. Step 33: With a statistical period of 50us, the rotor position statistically recorded in the current sampling period is θ(k), the rotor position in the next statistical period is θ(k+1), and the corresponding intermediate position before the disturbance is θ(0). Let Muti(θ) = (θ(k) - θ(0)) * (θ(k+1) - θ(0)); if Muti(θ) < 0, then the corresponding θ(k) is a zero-crossing point. Step 34: With a statistical period of 50us, let the outlet pressure of the current sampling period be P(k), the rotor position of the next statistical period be P(k+1), and the corresponding intermediate position before the disturbance be P(0). Let Muti(P) = (P(k) - P(0)) * (P(k+1) - P(0)). If Muti(P) < 0, then the corresponding P(k) is a zero crossing point. Step 35: Record the time when the motor rotor position crosses zero as t0. Taking t0 as the starting time, the number of zero-crossing difference cycles N=0. Start searching for the first zero-crossing time of the metering device outlet pressure, denoted as t1. Perform N+1 operations in each sampling cycle. The sampling cycle is 50us. At time t1, t1-t0=N*0.00005s. Let k=N, then the time difference between the zero-crossing point of a single rotor position and the zero-crossing point of the outlet pressure is k*0.00005s. Step 36: Each frequency point lasts for 10 cycles, for a total of 20 zero-crossing points. The time differences of the 20 zero-crossing points are weighted and averaged to obtain the average zero-crossing time difference as kave*0.00005s. Step 37: Let the frequency of the current sinusoidal disturbance be f(k). The phase lag angle corresponding to this frequency point is calculated as follows: θlag(k) = kave * 0.00005 * f(k) * 360. Step 38: Let θ(k) be the zero-crossing point of the valve position. Starting from this zero-crossing point, traverse the point with the maximum amplitude of the valve position within (1 / f(k)) / 0.00005 sampling periods, and denot it as θmax(k). Take the weighted average of θmax(k) over 10 sampling periods to obtain θmaxave(k). Step 39: Let P(k) be the zero point of the outlet pressure of the metering device. Starting from this zero point, within (1 / f(k)) / 0.00005 sampling periods, traverse the point with the maximum amplitude of the outlet pressure of the metering device, and denote it as Pmax(k). Take the weighted average of Pmax(k) of 10 sampling periods to obtain Pmaxave(k). Step 310: Record the sinusoidal amplitude of the metering device outlet pressure corresponding to each traversal frequency point f(k) as Pmaxave(k) and the sinusoidal amplitude of the motor rotor position as θmaxave(k); then the gain K(k) corresponding to this frequency point is Pmaxave(k) / θmaxave(k).

10. The method according to claim 6, characterized in that, Step 4 includes: Step 41: Record the amplitude ratio K(k) and phase difference θlag(k) corresponding to each frequency point f(k). Compress the frequency coordinates according to the logarithmic representation method of frequency points in the Bode plot and save the data. Step 42: Draw the Bode plot amplitude-frequency response and phase-frequency response diagrams based on the Bode plot data.

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