CN112014062A - Pose measurement system and measurement method for wind tunnel free flight test model - Google Patents

Abstract

The invention discloses a wind tunnel free flight test model pose measuring system which comprises a field pose capturing subsystem, a remote pose resolving subsystem and a model recycling subsystem. The field attitude capturing subsystem measures the angular velocity and the acceleration of the wind tunnel free flight test model by using an inertial sensor; the remote pose resolving subsystem is used for resolving the angular velocity and acceleration data of the wind tunnel free flight test model measured by the field pose capturing subsystem in real time or off-line to obtain pose information of the wind tunnel free flight test model; and the model recovery subsystem is used for recovering the wind tunnel free flight test model and the field attitude capture subsystem when the test is finished. The invention also discloses a measuring method of the measuring system. The method can solve the problems of less pose information acquisition freedom and short effective data length of the traditional high-speed photographing method for the wind tunnel free flight test, and is low in cost and reusable.

Description

A kind of wind tunnel free flight test model pose measurement system and measurement method

technical field

The invention belongs to the field of wind tunnel flight test, and relates to a position and attitude measurement system and a measurement method of a wind tunnel free flight test model.

Background technique

As an important branch in the field of wind tunnel testing, the wind tunnel free flight test technology is an important method for the study of the dynamic characteristics of the aircraft. The test principle is to capture the position and attitude of the test model under the condition that the dynamics of the wind tunnel test and the flight state are similar, and then obtain the static and dynamic stability derivative coefficients and other related aerodynamic coefficients of the aircraft.

At present, the pose capture of wind tunnel free-flight test models is based on high-speed photography methods. Its advantages are high pose capture accuracy, good anti-interference, and its application is now mature. However, limited by the wind tunnel test conditions, it currently has the following disadvantages: 1. It can only image in a two-dimensional plane, so it can only capture the pose information of three degrees of freedom. For lateral displacement, sideslip angle and roll angle displacement It cannot be obtained, which undoubtedly limits the application scope of free flight in the wind tunnel test; 2. Due to the limitation of the size range of the observation window in the wind tunnel test section and the scale of the model size, the flight time of the model within the scope of the observation window is short. This results in the inability to obtain a long enough effective recording time, which in turn affects the accurate analysis of the test results. Among them, Jiang Zenghui et al. in the patent "The acquisition method of shooting and recording time in the free flight test of the launch-type wind tunnel (CN 105258906B)" and the patent "A method of estimating the flight trajectory of a wind tunnel free flight test model (CN 104458202B)" respectively A flight trajectory estimation method and a launch-type wind tunnel free-flight test method are proposed to solve the problem of insufficient data volume due to the short shooting time of the model, but the amount of data obtained is still limited.

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is to overcome the deficiencies of the prior art, and provide a model pose measurement system and measurement method for a wind tunnel free flight test. Pose capture provides a new approach.

The technical solution of the present invention is:

A wind tunnel free flight test model pose measurement system, including an on-site pose capture subsystem, a remote pose calculation subsystem and a model recovery subsystem;

The on-site attitude capture subsystem uses inertial sensors to measure the angular velocity and acceleration of the wind tunnel free flight test model;

The remote position and attitude calculation subsystem performs real-time or offline calculation on the angular velocity and acceleration data of the wind tunnel free flight test model measured by the on-site attitude capture subsystem, and obtains the position and attitude information of the wind tunnel free flight test model;

Model recovery subsystem for recovering the wind tunnel free flight test model and field attitude capture subsystem at the end of the test.

The on-site attitude capture subsystem includes a power module, a CPU module, a bus module, an inertial sensor, a data storage module and a Bluetooth module;

Power supply module: supply power to each module of the on-site attitude capture subsystem;

CPU module: During the test, it sends data measurement instructions to the inertial sensor module, and controls the information transmission mechanism of the bus module;

Bus module: PCI bus is used, which is the public communication trunk for transmitting information between other modules;

Inertial sensor: used to measure and obtain the triaxial angular velocity and triaxial acceleration data of the wind tunnel free flight test model, and transmit it to the data storage module and the Bluetooth module through the bus module; among them, the inertial sensor adopts MEMS inertial sensor, embedded gyroscope and Accelerometer;

Data storage module: use a micro data storage card to store the data measured by the inertial sensor module;

Bluetooth module: Receive the data measured by the inertial sensor and send it out in real time.

The power supply module, CPU module, bus module, inertial sensor, data storage module and Bluetooth module of the field attitude capture subsystem are all integrated and packaged on a printed circuit board, which is installed on the wind tunnel free flight test model during operation The inner cavity, and the MEMS inertial sensor needs to be arranged on the rolling axis of the wind tunnel free flight test model, close to the center of mass of the model, and the MEMS inertial sensor x-axis is in the vertical plane of the wind tunnel free flight test model and points to the front of the model.

The installation position of the MEMS inertial sensor is within 30mm from the center of mass of the model.

The remote pose solving subsystem uses any of the following methods to solve the model pose:

1) Offline solution method: After the test, the inertial sensor data stored in the data storage module of the on-site attitude capture subsystem is read and the pose is calculated to obtain the pose of the wind tunnel free flight test model during the entire test process. information;

2) Online calculation method: by receiving the inertial sensor data sent by the Bluetooth module of the on-site attitude capture subsystem in real time, the online real-time calculation of the position and attitude information of the wind tunnel free flight test model is carried out.

The remote pose calculation subsystem is composed of an industrial computer with bluetooth.

The model recovery subsystem is placed after the diffuser section of the wind tunnel.

The measurement method of the pose measurement system of the wind tunnel free flight test model includes the following steps:

Step 1: Before the test, calibrate the inertial sensor of the on-site attitude capture subsystem, and obtain the coefficient matrix of the gyroscope and accelerometer;

Step 2: Prepare for the test

Place the on-site attitude capture subsystem in the inner cavity of the wind tunnel free flight test model, and power on the on-site attitude capture subsystem. The on-site attitude capture subsystem starts to work and collect data. At this time, the test preparation is completed and the wind tunnel test is ready. ;

Step 3: Conduct the Wind Tunnel Test

Open the wind tunnel, and the inertial sensor in the on-site attitude capture subsystem starts to collect the angular velocity and acceleration data of the effective wind tunnel free-flight test model; if the user needs to perform online calculation, the remote position and attitude calculation subsystem calculates in real time , to obtain the pose information of the wind tunnel free flight test model;

Step 4: After the test, the model recovery subsystem recovers the test model and the on-site attitude capture subsystem;

Step 5: The remote position and attitude calculation subsystem extracts the inertial sensor measurement data from the data storage module of the on-site attitude capture subsystem, and organizes it, intercepts the valid data of the test, and performs positioning based on the coefficient matrix of the gyroscope and accelerometer obtained in step 1. Attitude calculation, to obtain the position and attitude information of the wind tunnel free flight test model during the test; among which, the difference between the initial attitude and the nominal attitude is used as the attitude installation error;

Step 6: Repeat steps 2 to 5 to conduct wind tunnel tests in different states and calculate the pose information of the wind tunnel free flight test model until all test states are completed and the test ends.

The design of the cavity of the wind tunnel free flight test model should consider the installation of the on-site attitude capture subsystem. The installation error between the cavity of the wind tunnel free flight test model and the on-site attitude capture system should be less than 0.02mm.

The present invention has the following beneficial effects:

(1) Compared with the traditional wind tunnel free flight test using high-speed photography to capture the pose of the model, the present invention uses the inertial sensor to capture the pose, and can obtain the information of all 6 degrees of freedom of the three-axis position and attitude. The camera can obtain additional 3 degrees of freedom (yaw, roll and side shift) for high-speed photography. The invention greatly expands the application scope of the free flight test and can obtain more abundant and effective aerodynamic data.

(2) The present invention adopts MEMS inertial sensor to realize pose capture, which is low in price, small in occupied space, convenient in integration, can be directly placed inside the model and reused, and can obtain the data of the whole process of the test, which is not affected by the size range of the observation window and the size of the observation window. The limitation of the model size reduction ratio lays the foundation for the accurate analysis of the test results.

Description of drawings

Figure 1 is a schematic diagram of the pose measurement system of the wind tunnel free flight test model.

Figure 2 is the structural layout (top view) of the field attitude capture subsystem in the pose measurement system of the wind tunnel free flight test model, wherein 1 is the power module, 2 is the CPU module, 3 is the bus module, and 4 is the inertial sensor module, 5 is the data storage module, 6 is the Bluetooth module, 7 indicates the three-axis direction of the inertial sensor, and 8 is the rolling axis of the wind tunnel free flight test model;

Figure 3 is a flow chart of the measurement method of the pose measurement system of the wind tunnel free flight test model.

Detailed ways

The composition and use method of the present invention will be further described below in conjunction with the accompanying drawings.

The invention introduces inertial sensors into the pose measurement of the wind tunnel free flight test model for the first time. First, the inertial sensor can independently solve the six degrees of freedom information of position and attitude; secondly, the inertial sensor can greatly extend the effective data time, completely capture all attitude information from the model entering the flow field to the flying flow field, and obtain a rich amount of data. The disadvantages of the high-speed photography-based method in the prior art can be effectively solved.

The wind tunnel free flight test model pose measurement system of the present invention includes three subsystems, an on-site attitude capture subsystem, a remote attitude and attitude calculation subsystem, and a model recovery subsystem, as shown in Figure 1, and the details are as follows:

1. The on-site attitude capture subsystem is the core subsystem of the wind tunnel free flight test model pose measurement system. It uses inertial sensors to measure the angular velocity and acceleration data of the wind tunnel free flight test model.

The on-site attitude capture subsystem includes the following modules: power supply module, CPU module, bus module, inertial sensor, data storage module, and Bluetooth module. Its layout structure is shown in Figure 2. In Figure 2, 1 is a power supply module, 2 is a CPU module, 3 is a bus module, 4 is an inertial sensor module, 5 is a data storage module, 6 is a Bluetooth module, 7 indicates the three-axis direction of the inertial sensor, and 8 is a wind tunnel Free flight test model roll axis. It should be pointed out that, in order to make the presentation clearer, the size of each module in FIG. 2 is not scaled according to the actual module size. The above modules are integrated on a printed circuit board, packaged and installed inside the wind tunnel free flight test model.

The components and functions of each module are as follows:

a. Power supply module: its function is to provide power for each module of the on-site attitude capture subsystem, which is composed of a battery, a voltage divider circuit and related alarm devices.

b. CPU module: the control center of the on-site attitude capture subsystem. At the beginning of the test, it sends data measurement instructions to the inertial sensor module, and controls the information transmission mechanism of the bus module. The CPU module uses an embedded processor chip based on an ARM core with a simple instruction set and low cost as a CPU chip. Among them, the on-chip main program implanted in the CPU module runs in a self-starting mode after power-on.

c. Bus module: PCI bus is adopted, which is the public communication trunk for transmitting information between other modules.

d. Inertial sensor: used to measure the triaxial angular velocity and triaxial acceleration of the wind tunnel free flight test model, and transmit it to the data storage module and the Bluetooth module through the bus module. Among them, the inertial sensor adopts MEMS inertial sensor, embedded gyroscope and accelerometer. The layout position of the inertial sensor is very important for the accuracy of the model pose measurement. The requirements are as follows: it needs to be arranged on the rolling axis of the test model and is close to the center of mass of the model; the x-axis of the inertial sensor is in the vertical plane of the model and points to the model front.

e. Data storage module: used to save the data generated by the inertial sensor module. Data storage using a micro data memory card.

f. Bluetooth module: Receive the data measured by the inertial sensor and send it out in real time.

2. Remote position and attitude calculation subsystem: Based on the data measured by the inertial sensor of the on-site attitude capture subsystem, the position and attitude information of the test model is calculated. The position and attitude calculation subsystem consists of an industrial computer with bluetooth.

There are two calculation methods: a. Offline calculation method: by calculating the inertial sensor data saved in the data storage module of the on-site attitude capture subsystem, the model pose during the whole test process is obtained; b. Online calculation method : By receiving the inertial sensor data sent in real time by the on-site attitude capture subsystem tooth module, the model pose is calculated in real time online.

3. The model recovery subsystem is used to recover the wind tunnel free flight test model and the field attitude capture subsystem at the end of the test, so that the wind tunnel free flight test model and the field attitude capture subsystem can be reused and the test cost is reduced. Among them, in order not to affect the wind tunnel flow field, the model recovery subsystem is placed behind the wind tunnel diffusion section.

As shown in Figure 3, the measurement method of the wind tunnel free flight test model pose measurement system includes the following steps:

Step 1: Before the test, calibrate the inertial sensor of the on-site attitude capture subsystem, and obtain the coefficient matrix of the gyroscope and accelerometer. Among them, the gyroscope is calibrated by the turntable method, and the accelerometer is calibrated by the six-sided method.

Step 2: Prepare for the test

The on-site attitude capture subsystem is placed in the cavity of the wind tunnel free flight test model, and the installation error between the model cavity and the on-site attitude capture system should be less than 0.02mm. The on-site attitude capture subsystem is powered on, and the on-site attitude capture subsystem starts to work and collect data. At this point, the test preparation is complete, and the wind tunnel test is ready.

Step 3: Conduct the Wind Tunnel Test

Turn on the wind tunnel, and the inertial sensor in the on-site attitude capture subsystem starts to collect the angular velocity and acceleration data of the valid wind tunnel free flight test model; among them, the user can choose to use the online solution method or the offline solution method to solve the test. Model pose information. If the user needs to perform online calculation, the remote position and attitude calculation subsystem performs real-time calculation of the position and attitude based on the angular velocity and acceleration data and the coefficient matrix of the gyroscope and accelerometer obtained in step 1, and obtains the position and attitude of the wind tunnel free flight test model. information

Step 3: Conduct the Wind Tunnel Test

The inertial sensor in the field attitude capture subsystem measures the angular velocity and acceleration data of the wind tunnel free flight test model;

Step 4: After the test, the model recovery subsystem recovers the test model and the on-site attitude capture subsystem;

Step 5: The remote position and attitude calculation subsystem extracts the inertial sensor measurement data from the data storage module of the on-site attitude capture subsystem, organizes it, intercepts the valid data of the test, and conducts positioning based on the coefficient matrix of the gyroscope and accelerometer obtained in step 1. The attitude calculation is used to obtain the attitude and attitude information of the wind tunnel free flight test model during the test; the difference between the initial attitude and the nominal attitude is used as the attitude installation error;

Step 6: Repeat steps 2 to 5 to conduct wind tunnel tests in different states and calculate the pose information of the wind tunnel free flight test model until all test states are completed and the test ends.

The present invention measures the pose of the model based on the MEMS inertial sensor, provides a new way for capturing the pose of the model in the free flight test of the wind tunnel, and can overcome the problems of less freedom of obtaining pose information, short effective data length, and low cost in the traditional high-speed photography method. reusable.

Contents that are not described in detail in the specification of the present invention belong to the well-known technology of those skilled in the art.

Claims (9)

1. The utility model provides a wind-tunnel free flight test model position appearance measurement system which characterized in that: the system comprises a field attitude capturing subsystem, a remote pose resolving subsystem and a model recovery subsystem;

the field attitude capturing subsystem measures the angular velocity and the acceleration of the wind tunnel free flight test model by using an inertial sensor;

the remote pose resolving subsystem is used for resolving the angular velocity and acceleration data of the wind tunnel free flight test model measured by the field pose capturing subsystem in real time or off-line to obtain pose information of the wind tunnel free flight test model;

and the model recovery subsystem is used for recovering the wind tunnel free flight test model and the field attitude capture subsystem when the test is finished.

2. The wind tunnel free flight test model pose measurement system according to claim 1, characterized in that: the field attitude capturing subsystem comprises a power module, a CPU module, a bus module, an inertial sensor, a data storage module and a Bluetooth module;

a power supply module: supplying power to each module of the on-site attitude capture subsystem;

a CPU module: in the test process, a data measurement instruction is sent to the inertial sensor module, and an information transmission mechanism of the bus module is controlled;

a bus module: a PCI bus is adopted and is a public communication trunk line for transmitting information among other modules;

an inertial sensor: the device is used for measuring and acquiring triaxial angular velocity and triaxial acceleration data of the wind tunnel free flight test model, and transmitting the triaxial angular velocity and triaxial acceleration data to the data storage module and the Bluetooth module through the bus module; the inertial sensor adopts an MEMS inertial sensor, and a gyroscope and an accelerometer are embedded in the inertial sensor;

a data storage module: the data measured by the inertial sensor module is stored by adopting a micro data storage card;

a Bluetooth module: and receiving data measured by the inertial sensor and sending the data to the outside in real time.

3. The wind tunnel free flight test model pose measurement system according to claim 2, characterized in that: the power module, the CPU module, the bus module, the inertial sensor, the data storage module and the Bluetooth module of the on-site attitude capturing subsystem are integrated and packaged on a printed circuit board, the printed circuit board is mounted in an inner cavity of the wind tunnel free flight test model during working, the MEMS inertial sensor needs to be arranged on a rolling shaft of the wind tunnel free flight test model and is close to the mass center position of the model, and an x axis of the MEMS inertial sensor is in a vertical plane of the wind tunnel free flight test model and points to the front of the model.

4. The wind tunnel free flight test model pose measurement system according to claim 3, characterized in that: the installation position of the MEMS inertial sensor is within 30mm from the center of mass of the model.

5. The wind tunnel free flight test model pose measurement system according to claim 2, characterized in that: the remote pose resolving subsystem resolves the model pose by adopting any one of the following modes:

1) and an off-line calculating mode: after the test is finished, reading inertial sensor data stored in a data storage module of the on-site attitude capture subsystem and calculating the pose to obtain the pose information of the wind tunnel free flight test model in the whole test process;

2) and an online calculation mode: and the pose information of the wind tunnel free flight test model is resolved on line in real time by receiving the inertial sensor data sent by the field attitude capture subsystem Bluetooth module in real time.

6. The wind tunnel free flight test model pose measurement system according to claim 5, characterized in that: the remote pose resolving subsystem is composed of an industrial personal computer with Bluetooth.

7. The wind tunnel free flight test model pose measurement system according to claim 1, characterized in that: the model recovery subsystem is arranged behind the wind tunnel diffusion section.

8. The measurement method of the wind tunnel free flight test model pose measurement system according to any one of claims 1 to 7, characterized by comprising the following steps:

step 1: before testing, calibrating an inertial sensor of a field attitude capturing subsystem to obtain a coefficient matrix of a gyroscope and an accelerometer;

step 2: preparation for carrying out the test

Placing the field attitude capture subsystem in an inner cavity of a wind tunnel free flight test model, electrifying the field attitude capture subsystem, starting the field attitude capture subsystem to work and collect data, completing test preparation at the moment, and preparing to perform a wind tunnel test;

and step 3: performing a wind tunnel test

Starting the wind tunnel, and starting an inertial sensor in the on-site attitude capture subsystem to acquire effective angular velocity and acceleration data of the wind tunnel free flight test model; if the user needs to carry out online resolving, the remote pose resolving subsystem carries out real-time resolving to obtain pose information of the wind tunnel free flight test model;

and 4, step 4: after the test is finished, the model recovery subsystem recovers the test model and the field attitude capture subsystem;

and 5: the remote pose resolving subsystem extracts the measurement data of the inertial sensor from the data storage module of the field pose capturing subsystem, sorts the measurement data, intercepts effective test data, resolves the pose based on the coefficient matrix of the gyroscope and the accelerometer obtained in the step 1, and obtains pose information of the wind tunnel free flight test model in the test process; taking the difference value of the initial attitude and the nominal attitude as an attitude installation error;

and 6, repeating the steps 2 to 5, performing wind tunnel tests in different states, and resolving pose information of the wind tunnel free flight test model until all test states are finished, and finishing the test.

9. The measurement method according to claim 8, wherein the design of the inner cavity of the wind tunnel free flight test model considers the installation of the on-site attitude capture subsystem, and the matching installation error of the inner cavity of the wind tunnel free flight test model and the on-site attitude capture subsystem is less than 0.02 mm.

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