A continuous measurement system and measurement method of a DC transient transonic wind tunnel

Abstract

A continuous measurement system and method for a DC transient transonic wind tunnel belongs to the field of wind tunnel testing technology. Existing equipment suffers from minor timing differences in signals. This system's continuous angle-of-attack measurement device includes an angle-of-attack potentiometer and an angle-of-attack encoder. The outputs of the pressure sensor, strain gauge, and angle-of-attack potentiometer are connected to the input of an HBM data acquisition device. The HBM data acquisition device is bidirectionally connected to a data acquisition computer. The output of the angle-of-attack encoder is connected to the input of an IK220 board. The output of the IK220 board is connected to the input of the data acquisition computer. The data acquisition computer is bidirectionally connected to an Ethernet network. The Ethernet switch is bidirectionally connected to the data processing computer via Ethernet. This effectively solves the problem of timing differences in the acquired data caused by sequential acquisition from various channels. This method accurately obtains the aerodynamic characteristics within the sensitive angle-of-attack range and improves efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of wind tunnel testing, and in particular relates to a continuous measurement system and a measurement method of a direct current transient transonic wind tunnel. Background Art

[0002] The continuous measurement force test technology can realize the continuous measurement of the aerodynamic quantities of the aircraft model in the entire test angle of attack range, and can completely obtain the aerodynamic characteristics (static) of the model at all angles of attack. Compared with the step-variable angle of attack test method, it can obtain more test information and can more accurately obtain the aerodynamic characteristics of all angles of attack, especially the sensitive angle of attack range, providing reliable test data for aircraft model tests, and to a certain extent improve test efficiency and reduce test costs.

[0003] During the force measurement test, the model attitude angle is usually measured by an angle sensor, while the aerodynamic force and torque are measured by a balance. Due to the different response characteristics of the angle sensor and the balance, there is a small amount of timing difference between the signals. For step force measurement, the step stabilization time is much longer than this timing difference, so it has no effect on the test data. However, the continuous variable angle of attack test with a fast angle of attack speed makes the influence of the timing difference between the signals prominent, resulting in the angle of attack translation phenomenon of the continuous variable angle of attack force measurement test data. Summary of the invention

[0004] The present invention overcomes the deficiencies of the above-mentioned prior art and provides a continuous measurement system and a measurement method for a DC transient transonic wind tunnel. The system adopts an angle potentiometer whose output signal is an analog quantity combined with an angle encoder of a digital quantity, and selects an HBM data acquisition system with a parallel acquisition function, so that the angle of attack value of the model and the six-element output signal of the balance are acquired by the same data acquisition device; the problem of time sequence difference in the acquired data caused by the sequential acquisition method of each channel is effectively solved; the method accurately obtains the aerodynamic characteristics of the sensitive angle of attack range and improves the efficiency.

[0005] The technical solution of the present invention:

[0006] Technical Solution 1

[0007] A continuous measurement system for a direct current transient transonic wind tunnel comprises a pressure sensor, a strain balance, an angle of attack continuous measurement device, an HBM data acquisition device, a data acquisition computer, an IK220 board, an Ethernet switch and a data processing computer; the angle of attack continuous measurement device comprises an angle of attack potentiometer and an angle of attack encoder, the output end of the pressure sensor, the output end of the strain balance and the output end of the angle of attack potentiometer are respectively connected to the input end of the HBM data acquisition device, the HBM data acquisition device is bidirectionally connected to the data acquisition computer, the output end of the angle of attack encoder is connected to the input end of the IK220 board, the output end of the IK220 board is connected to the input end of the data acquisition computer, the data acquisition computer is interactively bidirectionally connected to the Ethernet, and the Ethernet switch is bidirectionally connected to the data processing computer via the Ethernet.

[0008] Furthermore, the angle of attack continuous measurement device also includes a support plate joint, a fairing, a south end cover, a potentiometer mounting seat, a bushing, a shaft, a cylindrical roller bearing, an encoder mounting seat, an encoder locking sleeve and a north end cover; a bushing is installed on the outside of the shaft, and cylindrical roller bearings are installed on both ends of the shaft, the cylindrical roller bearing on one side is connected to the potentiometer mounting seat, an angle of attack potentiometer is installed in the potentiometer mounting seat, the angle of attack potentiometer and the potentiometer mounting seat are installed with the south end cover on the outside, the cylindrical roller bearing on the other side is connected to the encoder mounting seat, an angle of attack encoder is installed in the encoder mounting seat, an encoder locking sleeve is covered on the outside of the angle of attack encoder, and the encoder mounting seat, the angle of attack encoder and the encoder locking sleeve are covered with the north end cover on the outside.

[0009] Furthermore, the angle of attack continuous measurement device also includes a hexagon socket head screw.

[0010] Technical Solution 2

[0011] A measurement method implemented by a continuous measurement system of a DC transient transonic wind tunnel according to technical solution 1 comprises the following steps:

[0012] Step a, determining the flow field fast follow-up adjustment;

[0013] Step b, determining the angle of attack running rate to be 1° / s;

[0014] Step c, determining the data sampling rate to be 2400 Hz;

[0015] Step d, determining the cut-off frequency to be 1.25 Hz;

[0016] Step e, synchronously collect measurement data; the signals of the pressure sensor, strain balance and the angle of attack potentiometer with analog output signals are transmitted to the data acquisition computer through the HBM data acquisition device, and the signal of the digital angle of attack encoder is also collected to the data acquisition computer through the IK220 board, and continuous measurement is performed;

[0017] Step f: Transmit the collected data to a data processing computer via the test site industrial Ethernet for filtering and signal synchronization correction processing.

[0018] Furthermore, the continuous measurement method comprises the following steps:

[0019] Step e1, in the stage of continuous acquisition of initial self-weight readings, the initial position of the model is zero position. After receiving the "start angle of attack" command from the central control system, the angle of attack system moves to the given initial position and sends an in-position signal to the central control system;

[0020] Step e2, the central control system sends a "start initial reading continuous acquisition" command to the data acquisition system to start continuous data acquisition;

[0021] Step e3: After the angle of attack system reaches the end position at a uniform speed, it sends an angle of attack command to the central control system;

[0022] Step e4, the central control system sends a message "end initial reading continuous acquisition" to the data acquisition system to end continuous acquisition and return the angle of attack system to zero;

[0023] Step e5, the angle of attack system returns to zero;

[0024] Step e6: During the blowing process, the central control system first commands the flow field control system to adjust the flow field, and starts the angle of attack after the flow field is stable. The angle of attack system moves to a given initial position and sends an in-position signal to the central control system;

[0025] Step e7, the central control system sends a "start reading and continuous acquisition" command to the data acquisition system to start continuous data acquisition;

[0026] Step e8: After the angle of attack system reaches the end position at a uniform speed, it sends an angle of attack command to the central control system;

[0027] Step e9, the central control system sends a "stop continuous reading" message to the data acquisition system to end the continuous acquisition and return the angle of attack system to zero;

[0028] Step e10: After the angle of attack returns to zero, the central control system instructs the flow field control system to close the pressure regulating valve, and the test ends.

[0029] Furthermore, the method for the data processing computer to perform signal synchronization correction processing includes the following steps:

[0030] Step f1, preprocessing the data by angle of attack smoothing;

[0031] Step f2, performing boundary processing to intercept the test data within the extended range of the angle of attack;

[0032] Step f3, performing signal synchronization correction on the data of the initial reading and the data of the blowing reading, and then interpolating the data of the initial reading based on the angle of attack sequence of the blowing reading;

[0033] Step f4, calculating the balance force and the correlation coefficient according to the data processing method of the conventional force measurement test;

[0034] Step f5: interpolate according to the required angle of attack sequence.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention provides a continuous measurement system and a measurement method for a direct current transient transonic wind tunnel. The system adopts an angle potentiometer whose output signal is an analog quantity and an angle encoder whose output signal is a digital quantity, so that the angle of attack value of the model and the six-element output signal of the balance are collected by the same data collection device; when realizing the synchronous collection of the balance aerodynamic load, flow field parameters and model posture, the HBM data collection system with a parallel collection function is selected, which fundamentally solves the problem that the VXI collection system has a time sequence difference in the collected data due to its serial collection mode of each channel, that is, the sequential collection mode of each channel;

[0037] The data sampling rate of this method is 2400Hz, and when the cutoff frequency is set to 1.25Hz, the clutter can be basically filtered out; the angle of attack speed is 1° / s during the continuous measurement test, and the angle of attack running rate of 1° / s is used to ensure the full development of the model flow, and the aerodynamic data obtained truly reflects the static aerodynamic force of the model under the corresponding incoming flow conditions; on the one hand, the continuous measurement obtains more information near the inflection point of the model lift characteristics and pitch moment characteristics, and accurately obtains the aerodynamic characteristics of the sensitive angle of attack range; on the other hand, compared with the conventional M number control method, the efficiency of the step measurement using the M number precise control method is improved, and energy saving is about 25% to 40% when M=1.0-1.2; the continuous measurement can be completed in 30s of blowing at an angle of attack speed of 1° / s, and the efficiency is significantly improved. Compared with the conventional M number control step measurement, energy saving is about 40% to 60%. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a system architecture diagram of the present invention;

[0039] Figure 2 It is a side view of the angle of attack continuous measuring device;

[0040] Figure 3 This is the front view of the angle of attack continuous measuring device;

[0041] Figure 4 It is the control flow chart of continuous measurement test;

[0042] Figure 5It is a flow chart of continuous measurement test data processing;

[0043] Figure 6 This is the installation position diagram of the continuous measuring device support plate joint and fairing.

[0044] In the figure: 1 support plate joint, 2 hexagon socket head screw, 3 fairing, 6 south end cover, 7 angle of attack potentiometer, 8 potentiometer mounting seat, 10 bushing, 11 shaft, 12 cylindrical roller bearing, 13 encoder mounting seat, 14 angle of attack encoder, 15 encoder locking sleeve, 16 north end cover. DETAILED DESCRIPTION

[0045] The present invention will be described in detail below with reference to the accompanying drawings. Specific implementation method 1

[0047] A continuous measurement system for a DC transient transonic wind tunnel, such as Figure 1 As shown, it includes a pressure sensor, a strain balance, an angle of attack continuous measurement device, an HBM data acquisition device, a data acquisition computer, an IK220 board, an Ethernet switch and a data processing computer; the angle of attack continuous measurement device includes an angle of attack potentiometer 7 and an angle of attack encoder 14, the output end of the pressure sensor, the output end of the strain balance, and the output end of the angle of attack potentiometer 7 are respectively connected to the input end of the HBM data acquisition device, the HBM data acquisition device is bidirectionally connected to the data acquisition computer, the output end of the angle of attack encoder 14 is connected to the input end of the IK220 board, the output end of the IK220 board is connected to the input end of the data acquisition computer, the data acquisition computer is interactively bidirectionally connected to the Ethernet, and the Ethernet switch is bidirectionally connected to the data processing computer via the Ethernet.

[0048] Working principle: The signals of the pressure sensor, balance strain force and angle of attack potentiometer 7 are transmitted to the data acquisition computer through the HBM data acquisition equipment. The signal of the digital angle of attack encoder 14 is also collected to the data acquisition computer through the IK220 board card, and then transmitted to the data processing computer through the test site industrial Ethernet for data processing.

[0049] By combining an angle potentiometer with analog output signals with an angle encoder with digital output signals, the model's angle of attack value and the six-element output signal of the balance can be collected by the same data acquisition device; when realizing the synchronous collection of the balance's aerodynamic load, flow field parameters and model posture, the HBM data acquisition system with parallel acquisition function was selected, which fundamentally solved the problem of timing difference in the collected data caused by the serial acquisition method of each channel of the VXI acquisition system, that is, the sequential acquisition method of each channel.

[0050] One of the key technologies of continuous measurement is to solve the problem of synchronous acquisition of model attitude angle and aerodynamic force during data acquisition. Because the measured signal has undergone essential changes from the step-by-step measurement method to the continuous scanning measurement method, it is necessary to solve the problem of real-time measurement of model attitude angle in the data measurement process to realize the synchronous acquisition of balance aerodynamic load, flow field parameters and model attitude. The invented continuous measurement device can realize the synchronous acquisition of model attitude angle and aerodynamic force.

[0051] Specifically, Figure 2 and Figure 3 As shown, the angle of attack continuous measurement device also includes a support plate joint 1, a fairing 3, a south end cover 6, a potentiometer mounting seat 8, a bushing 10, a shaft 11, a cylindrical roller bearing 12, an encoder mounting seat 13, an encoder locking sleeve 15 and a north end cover 16; the shaft 11 is externally mounted with a bushing 10, and cylindrical roller bearings 12 are mounted at both ends of the shaft 11, the cylindrical roller bearing 12 on one side is connected to the potentiometer mounting seat 8, an angle of attack potentiometer 7 is mounted in the potentiometer mounting seat 8, the angle of attack potentiometer 7 and the potentiometer mounting seat 8 are externally mounted with the south end cover 6, the cylindrical roller bearing 12 on the other side is connected to the encoder mounting seat 13, an angle of attack encoder 14 is mounted in the encoder mounting seat 13, an encoder locking sleeve 15 is externally sleeved on the angle of attack encoder 14, and the encoder mounting seat 13, the angle of attack encoder 14 and the encoder locking sleeve 15 are externally sleeved with the north end cover.

[0052] Specifically, the angle of attack continuous measuring device further includes a hexagon socket head screw 2 .

[0053] Specifically, a fairing 3 is installed on the support plate joint 1, and the angle of attack continuous measuring device is fixed on the support plate 17 through the support plate joint 1. Figure 6 As shown, the middle dotted line is the wind tunnel axis. Specific implementation method 2

[0055] A measurement method implemented by a continuous measurement system of a DC transient transonic wind tunnel according to the first embodiment comprises the following steps:

[0056] Step a, determining the flow field fast follow-up adjustment;

[0057] During the continuous measurement test, the model always moves at a certain speed, that is, the blockage of the model is constantly changing. This requires the control system of the DC transient transonic wind tunnel to constantly adjust the test flow field, so as to ensure that the Mach number of the model is always within the control accuracy requirements during the uniform motion of the angle of attack. The ability to quickly follow the flow field is the primary condition for the DC transient transonic wind tunnel to achieve continuous measurement.

[0058] Step b, determining the angle of attack running rate to be 1° / s;

[0059] The selection of the model angle of attack operating rate should not only consider the impact on the wind tunnel flow field, the effective frequency band of the measurement signal and the quality of the test data, but also take into account the economic requirements of the wind tunnel operation. Therefore, the selection of the model angle of attack operating rate is the core issue of the continuous variable angle of attack test in a transient high-speed wind tunnel. If the angle of attack operating rate is too fast, it is not only difficult to ensure the full development of the model flow, resulting in the hysteresis effect of the aerodynamic characteristics in the continuous measurement test technology, affecting the data quality, but also increasing the difficulty of flow field follow-up adjustment and signal measurement, and it is possible to increase the pulsation of the flow field in the test section, affecting the test data quality. However, if the model angle of attack operating rate is too low, the economy is difficult to meet the requirements of engineering applications. Therefore, the test results of different angle of attack operating rates must be compared and analyzed with the step measurement test results, and the optimal angle of attack operating rate during continuous measurement must be selected to ensure that no aerodynamic characteristic hysteresis occurs at this angle of attack rate.

[0060] Taking into account both data quality and operational economy, the angle of attack speed can be 1° / s during continuous measurement tests. The use of an angle of attack speed of 1° / s can ensure the full development of the flow around the model, and the aerodynamic data obtained truly reflects the static aerodynamic force of the model under the corresponding incoming flow conditions.

[0061] Step c, determining the data sampling rate to be 2400 Hz;

[0062] When selecting the data sampling rate, considering the frequency response of the balance itself of 200Hz to 300Hz, the sampling rate can be greater than 4 times, that is, greater than 1200Hz. However, in order to have enough data samples for data analysis and subsequent data processing, the sampling rate is selected as 2400Hz.

[0063] Step d, determining the cut-off frequency to be 1.25 Hz;

[0064] A fundamental difference between the continuous measurement of the continuously variable angle of attack signal and the step measurement of the step variable angle of attack signal is that the measured signal is transformed from a constant static DC signal to a changing dynamic signal composed of different frequency components. From the frequency domain distribution, the main energy distribution of the aerodynamic signal is concentrated in the low frequency range of 0-5Hz. As the frequency increases, the power spectrum density drops sharply. Ideally, in the signal conditioning process, the cutoff frequency of the low-pass filter should ensure that the effective signal frequency components pass, that is, the low-pass filter cutoff frequency fc should take a higher value as possible. If the value of fc is too low, the effective components of the actual signal will be filtered out together with the interference signal, and the delay of the measurement signal will also increase, resulting in measurement distortion. However, in the actual measurement process, due to the existence of various interference signals, the low-pass filter must suppress the interference signal while ensuring that the effective signal components are not missed. In order to effectively suppress the interference signal, the value of fc should be a lower value. Therefore, in the process of the continuous variable angle of attack force measurement test, ensuring that the effective frequency components of the measurement signal are not missed and suppressing various interferences through filtering are contradictory. The reasonable selection of the filter cutoff frequency is one of the keys to the success of this test.

[0065] When digital filtering, that is, when the cutoff frequency is selected, when the measured signal is large, the data with cutoff frequencies of 1.25Hz and 2.5Hz have good consistency, but when the measured signal is small, the data interference signal with a cutoff frequency of 2.5Hz is still large, and the data fluctuation is large. The cutoff frequency of 1.25Hz basically filters out the excess interference signal, so the cutoff frequency is 1.25Hz.

[0066] Step e, synchronously collect measurement data; the signals of the pressure sensor, strain balance and the angle of attack potentiometer 7 with analog output signals are transmitted to the data acquisition computer through the HBM data acquisition device, and the signal of the digital angle of attack encoder 14 is also collected to the data acquisition computer through the IK220 board, and continuous measurement is performed;

[0067] During the force measurement test, the model attitude angle is usually measured by an angle sensor, while the aerodynamic force and torque are measured by a balance. Due to the different response characteristics of the angle sensor and the balance, there is a small amount of timing difference between the signals. The continuous variable angle of attack test with a fast angle of attack speed makes the influence of the timing difference between the signals prominent, causing the angle of attack translation phenomenon of the continuous variable angle of attack force measurement test data. Therefore, it is necessary to calculate the timing difference between the signals in the wind tunnel test, and synchronize the data accordingly to ensure the accuracy of the continuous variable angle of attack force measurement test data.

[0068] When measuring the model attitude angle, an angle potentiometer with analog output signal is combined with a digital angle encoder, so that the model's angle of attack value and the six-element output signal of the balance can be collected by the same data acquisition device. When realizing the synchronous acquisition of the balance aerodynamic load, flow field parameters and model attitude, the HBM data acquisition system with parallel acquisition function is selected, which fundamentally solves the problem of timing difference in the collected data caused by the serial acquisition method of each channel of the VXI acquisition system, that is, the sequential acquisition method of each channel.

[0069] Step f: Transmit the collected data to a data processing computer through the test site industrial Ethernet for data processing. The data processing method includes filtering processing and signal synchronization correction processing.

[0070] During the continuous acquisition process, useful balance signals may be distributed in the high-frequency band. Therefore, during the acquisition process, the cutoff frequency of the hardware filter will be much higher than the filter cutoff frequency of the step acquisition test. This will cause the low-frequency part to contain a large amount of interference signals that are not filtered out, so further filtering processing is required.

[0071] Since continuous scanning is collected during the movement of the model, interference cannot be eliminated by averaging. In view of the excellent performance of wavelet transform in signal noise reduction processing, such as low entropy, multi-resolution, decorrelation and strong adaptability, wavelet denoising is used for filtering processing to retain the peaks and mutations in the useful signal.

[0072] During the force measurement test, the model attitude angle is measured by the angle potentiometer, while the aerodynamic force and torque are measured by the balance. Due to the different response characteristics of the potentiometer and the balance, there is a small time difference of about 0-0.05s between the signals. The continuous variable angle of attack test with a fast angle of attack speed makes the influence of the time difference between the signals prominent, thus causing the angle of attack translation phenomenon in the continuous variable angle of attack force measurement test data.

[0073] In order to accurately calculate the timing difference between the signals, it is necessary to use the cross-correlation function. The principle is: assuming that the time history of two stationary random signals is x(t) and y(t), the cross-correlation function R of the two signals is xy (τ) is formula (1):

[0074]

[0075] According to the properties of the cross-correlation function, assuming that the angle of attack signal x(t) is the input signal of the system, and the balance signal y(t) is the output signal of the system, then the cross-correlation function R xy (τ) The τ at the highest peak is the delay time difference between the balance element and the angle potentiometer. Experimental data processing method.

[0076] By applying the cross-correlation function, the timing difference between each signal and the angle potentiometer in the wind tunnel test can be accurately calculated. Taking the timing of the angle potentiometer signal as the standard timing, the original data is aligned and corrected to obtain completely synchronized original data, thereby ensuring the accuracy of the test data.

[0077] Specifically, Figure 4 As shown, the continuous measurement is divided into two stages, the continuous collection stage of the initial self-weight reading and the continuous collection stage of the blowing data. The continuous measurement method includes the following steps:

[0078] Step e1, in the stage of continuous acquisition of initial self-weight readings, the initial position of the model is zero position. After receiving the "start angle of attack" command from the central control system, the angle of attack system moves to the given initial position and sends an in-position signal to the central control system;

[0079] Step e2, the central control system sends a "start initial reading continuous acquisition" command to the data acquisition system to start continuous data acquisition;

[0080] Step e3: After the angle of attack system reaches the end position at a uniform speed, it sends an angle of attack command to the central control system;

[0081] Step e4, the central control system sends a message "end initial reading continuous acquisition" to the data acquisition system to end continuous acquisition and return the angle of attack system to zero;

[0082] Step e5, the angle of attack system returns to zero;

[0083] Step e6: During the blowing process, the central control system first commands the flow field control system to adjust the flow field, and starts the angle of attack after the flow field is stable. The angle of attack system moves to a given initial position and sends an in-position signal to the central control system;

[0084] Step e7, the central control system sends a "start reading and continuous acquisition" command to the data acquisition system to start continuous data acquisition;

[0085] Step e8: After the angle of attack system reaches the end position at a uniform speed, it sends an angle of attack command to the central control system;

[0086] Step e9, the central control system sends a "stop continuous reading" message to the data acquisition system to end the continuous acquisition and return the angle of attack system to zero;

[0087] Step e10: After the angle of attack returns to zero, the central control system instructs the flow field control system to close the pressure regulating valve, and the test ends.

[0088] Specifically, Figure 5 As shown, the method for performing signal synchronization correction processing by the data processing computer includes the following steps:

[0089] Step f1, preprocessing the data by angle of attack smoothing;

[0090] Step f2, performing boundary processing to intercept the test data within the extended range of the angle of attack;

[0091] Step f3, performing signal synchronization correction on the data of the initial reading and the data of the blowing reading, and then interpolating the data of the initial reading based on the angle of attack sequence of the blowing reading;

[0092] Step f4, calculating the balance force and the correlation coefficient according to the data processing method of the conventional force measurement test;

[0093] Step f5: interpolate according to the required angle of attack sequence.

[0094] During data processing, the data is first preprocessed to intercept the test data within the extended range of the angle of attack. Then, the data of the initial readings and the data of the blowing readings are corrected for signal synchronization. The initial readings are interpolated based on the angle of attack sequence of the blowing readings. Finally, the balance force and the correlation coefficient are calculated according to the data processing method of the conventional force measurement test. Finally, the required angle of attack sequence is interpolated, which effectively improves the efficiency of wind tunnel tests, saves energy, and obtains test data that changes continuously with speed and angle of attack. In particular, key technologies such as real-time acquisition, noise reduction and data post-processing of continuously measured test data in DC transient transonic wind tunnels are fundamentally solved.

Claims

1. A continuous measurement method for a DC transient transonic wind tunnel, characterized in that: A continuous measurement system for a direct current transient transonic wind tunnel based on a continuous measurement method comprises a pressure sensor, a strain balance, an angle of attack continuous measurement device, an HBM data acquisition device, a data acquisition computer, an IK220 board, an Ethernet switch and a data processing computer; the angle of attack continuous measurement device comprises an angle of attack potentiometer (7) and an angle of attack encoder (14); the output end of the pressure sensor, the output end of the strain balance and the output end of the angle of attack potentiometer (7) are respectively connected to the input end of the HBM data acquisition device, the HBM data acquisition device is bidirectionally connected to the data acquisition computer, the output end of the angle of attack encoder (14) is connected to the input end of the IK220 board, the output end of the IK220 board is connected to the input end of the data acquisition computer, the data acquisition computer is bidirectionally connected to the Ethernet, and the Ethernet switch is bidirectionally connected to the data processing computer via the Ethernet; The continuous measurement method includes the following steps: Step a, determining the flow field fast follow-up adjustment; Step b, determining the angle of attack running rate to be 1° / s; Step c, determining the data sampling rate to be 2400 Hz; Step d, determining the cut-off frequency to be 1.25 Hz; Step e, synchronously collect measurement data; the signals of the pressure sensor, the strain balance and the angle of attack potentiometer (7) with analog output signals are transmitted to the data acquisition computer through the HBM data acquisition device, and the signal of the digital angle of attack encoder (14) is also collected to the data acquisition computer through the IK220 board, and continuous measurement is performed; specifically: Step e1, in the initial reading continuous acquisition stage, the initial position of the model is the zero position. After receiving the "start angle of attack" command from the central control system, the angle of attack system moves to the given initial position and sends an in-position signal to the central control system; Step e2, the central control system sends a "start initial reading continuous acquisition" command to the data acquisition system to start continuous data acquisition; Step e3: After the angle of attack system reaches the end position at a uniform speed, it sends an angle of attack command to the central control system; Step e4, the central control system sends "end initial reading continuous acquisition" to the data acquisition system to end continuous acquisition and return the angle of attack system to zero; Step e5, the angle of attack system returns to zero; Step e6: During the blowing process, the central control system first commands the flow field control system to adjust the flow field, and starts the angle of attack after the flow field is stable. The angle of attack system moves to a given initial position and sends an in-position signal to the central control system; Step e7, the central control system sends a "start reading and continuous acquisition" command to the data acquisition system to start continuous data acquisition; Step e8: After the angle of attack system reaches the end position at a uniform speed, it sends an angle of attack command to the central control system; Step e9, the central control system sends "end continuous reading" to the data acquisition system to end continuous acquisition, and returns the angle of attack system to zero; Step e10, after the angle of attack returns to zero, the central control system instructs the flow field control system to close the pressure regulating valve, and the test ends; Step f, transmitting the collected data to a data processing computer through the test site industrial Ethernet for filtering and signal synchronization correction processing, wherein the method for the data processing computer to perform signal synchronization correction processing includes the following steps: Step f1, preprocessing the data by angle of attack smoothing; Step f2, performing boundary processing to intercept the test data within the extended range of the angle of attack; Step f3, performing signal synchronization correction on the data of the initial reading and the data of the blowing reading, and then interpolating the data of the initial reading based on the angle of attack sequence of the blowing reading; Step f4, calculating the balance force and the correlation coefficient according to the data processing method of the conventional force measurement test; Step f5: interpolate according to the required angle of attack sequence.

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