CN114923660A - Wind tunnel free flight test flight control system based on embedded controller - Google Patents

Abstract

The invention discloses a flight control system for a wind tunnel model free flight test based on an embedded controller, and belongs to the field of wind tunnel free flight tests. The aircraft model is respectively provided with a flight control computer, an airborne sensor, a steering engine control surface and a power system. In the test process, the main control computer sends an operating instruction to the flight control computer, the flight control computer collects data of each airborne sensor, runs a flight control law algorithm, controls a control plane and a power system of the steering engine, completes control over the attitude and the spatial position of the aircraft model, transmits the flight state to the main control computer in real time, and the flight control computer is realized by adopting an embedded controller. The invention can meet the test requirements of different types of machines, and can meet the different test requirements by adopting a modular programming mode. The invention can obtain high-quality test data and reduce test cost and risk.

Description

Flight control system for free flight test in wind tunnel based on embedded controller

technical field

The invention belongs to the field of wind tunnel tests, and in particular relates to a free flight test flight control system of a wind tunnel model based on an embedded controller.

Background technique

The wind tunnel free-flight test is based on similar criteria, and the six-degree-of-freedom motion is not restricted. It can simulate the flight characteristics of the aircraft itself and the closed-loop control flight process. In the early stage of aircraft development, the overall design and flight control verification can be effectively carried out to realize the aerodynamic/ An important means of flight/control integration research. Compared with the atmospheric model flight test, the wind tunnel free flight test can reduce the test risk, improve the test efficiency and test data accuracy, the test environment is controllable, repeatable and can reduce the test cost. However, the wind tunnel environment cannot receive GNSS and geomagnetic signals, and cannot measure the heading angle and spatial position. Therefore, a free flight test flight control system of the wind tunnel model based on an embedded controller is required.

SUMMARY OF THE INVENTION

Based on the above shortcomings, the purpose of the present invention is to provide a free flight test flight control system for a wind tunnel model based on an embedded controller, which controls the attitude and spatial position of the aircraft model, collects and stores test data, and satisfies the requirements of different aircraft types. Require.

The technical scheme adopted by the present invention is as follows: a wind tunnel model free flight test flight control system based on an embedded controller, including a main control computer and a flight control computer, the flight control computer and the main control computer communicate with each other through wireless network for data and Command interaction, the aircraft model is equipped with flight control computer, airborne sensors, steering gear rudder surface and power system, respectively, hoists are installed on the upper and lower walls of the wind tunnel support frame, and the aircraft model is hoisted by a safety rope to keep it in the wind tunnel In the central area of the test section, the nose is facing the incoming flow and is kept in a horizontal state. The airborne sensors include inertial sensors, weather vane sensors, pressure sensors, spatial position sensors and non-contact Hall effect sensors.

The flight control computer adopts an embedded controller to run the flight control computer software. The flight control computer software includes a network communication module, a configuration file module, a data acquisition module, a position and attitude control module, a hardware drive module and a data storage module. The computer sends manipulation instructions to the flight control computer, and the flight control computer software collects the data of each airborne sensor, runs the flight control law algorithm, controls the rudder surface and power system of the steering gear, completes the control of the attitude and spatial position of the aircraft model, and adjusts the flight status. Real-time transmission to the host computer.

The main control computer runs the main control computer software. The main control computer software includes a parameter configuration module, an equipment calibration module, a control instruction module and a data display module. The main control computer software communicates with the basic parameter configuration information, equipment calibration data and control instructions through wireless network communication. Send to the flight control computer software, and the flight control calculation software sends the test data to the main control computer software through wireless network communication.

The rudder surface of the aircraft model is equipped with a non-contact Hall effect sensor, and the feedback signal of the rudder surface angle is uploaded to the flight control computer.

Inertial sensors are installed in the aircraft model to measure the pitch angle, roll angle, pitch angular velocity, roll angular velocity, yaw angular velocity, X, Y, and Z axis acceleration of the aircraft model.

The wind vane sensor is installed on the head of the aircraft, the wind vane drives the encoder, and the flight control computer collects the A, B, and Z phase signals of the incremental encoder, and calculates the angle of attack and sideslip angle of the aircraft; the pressure measurement is embedded in the head of the aircraft In the wind tunnel, measure the pressure hole pressure at each angle of attack and sideslip angle in advance, and store it in the memory of the flight control computer. During the flight test, the flight control computer collects the voltage signal of the pressure sensor, and solves it through the pressure interpolation of each pressure hole. Calculate the angle of attack and sideslip angle of the aircraft, and finally obtain accurate data by combining the two measurement methods through the Kalman filter algorithm.

The master and slave sensors of the spatial position sensor are respectively installed around the wind tunnel support device, and the ultra-wideband wireless carrier communication technology is used to measure the space position of the aircraft model. The label sensor is installed inside the model, and the ultra-wideband wireless carrier signal sent by the label sensor will It is received from the sensor, decodes the angle and time difference information of the ultra-wideband wireless carrier signal from the sensor, and then transmits these data to the main sensor, and solves the spatial position through the arrival angle positioning algorithm and the arrival time difference positioning algorithm. The flight control computer uses TCP/IP The data collected by the main sensor is obtained, and the X, Y, and Z axis spatial positions of the aircraft are calculated.

Further, the functions of the parameter configuration module include: storage path and frequency configuration, the transmission rate configuration of the main control computer and the flight control computer, the parameter configuration of the flight control law and the selection of sensor types; the functions of the equipment calibration module include: each sensor System reset and rudder surface angle linearization calibration; the control command module includes: attitude and space position open-loop control and closed-loop control switching operations, curve excitation control and program and remote control switching operations; the data display module Functions include: aircraft model attitude angle, spatial position, rudder surface angle and engine thrust display.

Further, the flight control computer software includes a network communication module, a configuration file module, a data acquisition module, a position and attitude control module, a hardware drive module, a data storage module, and the like. Among them, the functions of the network communication module include: command/data communication between the main control computer and the flight control computer; the functions of the configuration file module include: storage path and frequency configuration files, transmission rate configuration files of the main control computer and flight control computer, and flight control law parameter configuration The functions of the data acquisition module include: data acquisition of wind vane sensors, pressure sensors, non-contact Hall effect sensors, etc.; Steering gear rudder surface actuation command, engine actuation command and thrust vectoring device actuation command, etc.; the functions of the hardware drive module include: according to the position and attitude control module command, generate the data of the steering gear rudder surface and the engine analysis and execution; the function of the data storage module Including: storage of test data during flight test.

Further, the flight control computer collects airborne sensor data, including: angle of attack, sideslip angle, pitch angle, roll angle, pitch angular velocity, roll angular velocity, yaw angular velocity and X, Y, Z axis acceleration data In order to control the attitude control of the aircraft, the spatial position data of the X, Y, and Z axes are used to control the position of the aircraft. The flight control law algorithm calculates the control amount of the rudder surface of the steering gear and the control amount of the power system according to the airborne sensor data. The quantity needs to be converted into a PWM signal by the flight control computer, and finally the steering gear rudder surface and the power system are controlled by the PWM signal, and the power system transmits the speed signal to the flight control computer through the PWM signal.

Beneficial effects and advantages of the present invention: the present invention can obtain all accurate test data during flight, and overcomes the influence that GNSS and geomagnetic signals cannot be received inside the wind tunnel environment. The present invention adopts the modular programming mode, which can fulfill different test requirements. The test system has the ability to support the integrated test and research capabilities of advanced fighter aerodynamics/flight/control.

Description of drawings

Figure 1 is the software schematic diagram of the wind tunnel free flight control system based on the embedded controller.

Figure 2 is the experimental schematic diagram of the wind tunnel free flight control system based on the embedded controller.

Fig. 3 is a flow chart of a free flight test in a wind tunnel based on the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings:

Example 1

A wind tunnel model free flight test flight control system based on an embedded controller, comprising a main control computer, a flight control computer and an aircraft model, the flight control computer and the main control computer communicate data and instructions through wireless network communication, and the aircraft model separately The flight control computer, airborne sensor, steering gear rudder surface and power system are installed, and winches are installed on the upper and lower walls of the wind tunnel support frame respectively. The head is facing the incoming flow and maintains a horizontal state, and it is characterized in that the on-board sensors include inertial sensors, weather vane sensors, pressure sensors, spatial position sensors and non-contact Hall effect sensors,

As shown in Figure 1, the main control computer sends manipulation instructions to the flight control computer, and the flight control computer software collects the data of each airborne sensor, runs the flight control law algorithm, controls the steering gear rudder surface and the power system, and completes the aircraft model attitude and space. Position control, and transmit the flight status to the main control computer in real time; the flight control computer in this embodiment is implemented by an embedded controller, which is based on ZYNQ-7000, adopts ARM+FPGA architecture, runs an embedded real-time operating system, and has Analog input and output, digital input and output, Gigabit Ethernet, CAN, USB, serial (RS232/422/485) and SDHC ports, and other interfaces can be expanded through programmable FPGA. The flight control software adopts a modular programming method, and different test requirements can be completed with simple changes.

As shown in Figure 2, the flight control computer runs the flight control computer software. The flight control computer software includes a network communication module, a configuration file module, a data acquisition module, a position and attitude control module, a hardware drive module and a data storage module. The flight control computer software functions Including network communication module, configuration file module, data acquisition module, position and attitude control module, hardware drive module, data storage module, etc. Among them, the functions of the network communication module include: command/data communication between the main control computer and the flight control computer; the functions of the configuration file module include: storage path and frequency configuration files, transmission rate configuration files of the main control computer and flight control computer, and flight control law parameter configuration The functions of the data acquisition module include: data acquisition of wind vane sensors, pressure sensors, non-contact Hall effect sensors, etc.; Steering gear rudder surface actuation command, engine actuation command and thrust vectoring device actuation command, etc.; the functions of the hardware drive module include: according to the position and attitude control module command, generate the data of the steering gear rudder surface and the engine analysis and execution; the function of the data storage module Including: storage of test data during flight test.

The main control computer runs the main control computer software. The main control computer software includes a parameter configuration module, an equipment calibration module, a control instruction module and a data display module. The main control computer software communicates with the basic parameter configuration information, equipment calibration data and control instructions through wireless network communication. Send to the flight control computer software, the flight control calculation software sends the test data to the main control computer software through wireless network communication, the parameter configuration information is stored in the configuration file module, the data acquisition module collects the data of each sensor system, and the position and attitude control module runs the filter Control law algorithm, control hardware driver module. The data storage module stores test data for analysis and research.

Parameter configuration module functions include: storage path and frequency configuration, main control computer and flight control computer transmission rate configuration, flight control law parameter configuration, sensor type selection, etc.; equipment calibration module functions include: reset each sensor system, rudder surface angle linear The control command module includes: open-loop control and closed-loop control switching operation of attitude and spatial position, curve excitation control (step, square wave, even shock wave, sine wave, 3211, frequency sweep, etc.), program and remote control Control switching operations, etc.; the functions of the data display module include: display of aircraft model attitude angle, spatial position, rudder surface angle, engine thrust, etc.

The rudder surface of the aircraft model is equipped with a non-contact Hall effect sensor, and the feedback signal of the rudder surface angle is uploaded to the flight control computer.

Inertial sensors are installed in the aircraft model to measure the pitch angle, roll angle, pitch angular velocity, roll angular velocity, yaw angular velocity, X, Y, and Z axis acceleration of the aircraft model.

Due to the shielding inside the wind tunnel environment, GNSS and geomagnetic signals cannot be received, that is, the heading angle and spatial position cannot be measured. The invention obtains the angle of attack and the sideslip angle by means of fusion of the vane sensor and the pressure sensor, instead of the heading angle. The wind vane sensor is installed on the head of the aircraft, the wind vane drives the encoder, and the flight control computer collects the A, B, and Z phase signals of the incremental encoder, and calculates the angle of attack and sideslip angle of the aircraft; the pressure measurement is embedded in the head of the aircraft In the wind tunnel, measure the pressure hole pressure at each angle of attack and sideslip angle in advance, and store it in the memory of the flight control computer. During the flight test, the flight control computer collects the voltage signal of the pressure sensor, and solves it through the pressure interpolation of each pressure hole. Calculate the angle of attack and sideslip angle of the aircraft, and finally obtain accurate data by combining the two measurement methods through the Kalman filter algorithm.

The master and slave sensors of the spatial position sensor are respectively installed around the wind tunnel support device, and the ultra-wideband wireless carrier communication technology is used to measure the space position of the aircraft model. The label sensor is installed inside the model, and the ultra-wideband wireless carrier signal sent by the label sensor will It is received from the sensor, decodes the angle and time difference information of the ultra-wideband wireless carrier signal from the sensor, and then transmits these data to the main sensor, and solves the spatial position through the arrival angle positioning algorithm and the arrival time difference positioning algorithm. The flight control computer uses TCP/IP The data collected by the main sensor is obtained, and the X, Y, and Z axis spatial positions of the aircraft are calculated.

The flight control computer collects the airborne sensor data, among which the angle of attack, sideslip angle, pitch angle, roll angle, pitch angular velocity, roll angular velocity, yaw angular velocity, X, Y, Z axis acceleration are used to control the attitude control of the aircraft, X, The spatial positions of the Y and Z axes are used to control the position of the aircraft. The flight control law algorithm calculates the control quantities of the steering gear rudder surface and the power system according to the airborne sensor data. The calculated control quantities need to be converted into PWM by the flight control computer. signal, and finally control the rudder surface of the steering gear and the power system (the power system includes the electronic governor and the ducted fan) through the PWM signal. The steering gear is controlled to drive the connecting rod to rotate the rudder surface, and the angle feedback of the rudder surface is realized by a non-contact Hall effect sensor. The deflection of the metal rotating shaft of the rudder surface forms a declination angle with the Hall effect sensor, resulting in a magnetic field change, and the angle of the rudder surface is changed by the SPI signal. The signal is transmitted to the flight control computer. The sensor is small in size, high in precision and strong in anti-interference ability. Control the electronic governor to drive the ducted fan to provide thrust. The electronic governor can provide a maximum voltage of 12S (12×4.2V=50.4V) and a maximum current of 200A, which can meet the power requirements of various types of ducted fans. It can provide a maximum thrust of 15kg, which can meet the thrust requirements of various aircraft models. The speed feedback of the ducted fan is realized by the non-contact alternating current method. By collecting two phases of the three-phase alternating current of the engine, the engine speed is obtained by the two-phase commutation frequency, and the speed signal is transmitted to the flight control computer through the PWM signal. The method does not require direct contact with the engine and does not affect the thrust of the ducted fan.

This embodiment also relates to a safety protection system to ensure the safety of test personnel and aircraft models. The hoist is installed on the upper and lower walls of the support frame, the Dyneema rope is used to hoist the aircraft model, and the lift is independently controlled by the remote control. This way of protecting the model up and down is convenient and fast, which ensures that the aircraft model moves in a safe area, and is convenient for test personnel to operate.

Example 2

This embodiment is based on the control system of Embodiment 1, and the free flight test process of the wind tunnel is carried out, as shown in Figure 3, and the specific steps are as follows:

Step 1. When there is no wind in the wind tunnel, tie the upper and lower safety ropes to the suspension point at the center of gravity of the model, and adjust the upper and lower winches so that the aircraft model is in the center area of the wind tunnel test section, the nose is facing the incoming flow, and it is basically horizontal;

Step 2. Start with a wind speed of 10m/s. After the wind tunnel flow field becomes stable, turn on the closed-loop control of the flight control system;

Step 3. Increase the wind speed to the test wind speed. When the wind speed slowly rises, the safety rope is continuously loosened through the upper and lower winches, and the throttle is gradually increased to the trim thrust;

Step 4. After reaching the target wind speed, through the operation of the operator, make the aircraft model maintain 1g level flight in the center area of the wind tunnel flow field;

Step 5. Carry out flight test verification;

Step 6. After completing the test, stop the wind, gradually reduce the throttle, tighten the safety rope through the upper and lower winches, and finally close the flight control system;

Step 7, the test is over, and the motion parameters during the test are analyzed.

Claims (4)

1. A wind tunnel model free flight test flight control system based on an embedded controller, including a main control computer and a flight control computer, the flight control computer and the main control computer communicate data and instructions through wireless network communication, and the aircraft model is installed separately. There are flight control computer, on-board sensors, steering gear rudder surface and power system. Windlasses are installed on the upper and lower walls of the wind tunnel support frame, and the aircraft model is hoisted through safety ropes so that it is in the center area of the wind tunnel test section. Facing the incoming flow and maintaining a horizontal state, the airborne sensor includes an inertial sensor, a weather vane sensor, a pressure sensor, a spatial position sensor and a non-contact Hall effect sensor; The flight control computer adopts an embedded controller to run the flight control computer software. The flight control computer software includes a network communication module, a configuration file module, a data acquisition module, a position and attitude control module, a hardware drive module and a data storage module. The computer sends manipulation instructions to the flight control computer, and the flight control computer software collects the data of each airborne sensor, runs the flight control law algorithm, controls the rudder surface and power system of the steering gear, completes the control of the attitude and spatial position of the aircraft model, and adjusts the flight status. Real-time transmission to the main control computer; The main control computer runs the main control computer software. The main control computer software includes a parameter configuration module, an equipment calibration module, a control instruction module and a data display module. The main control computer software communicates with the basic parameter configuration information, equipment calibration data and control instructions through wireless network communication. Send to the flight control computer software, the flight control calculation software sends the test data to the main control computer software through wireless network communication, The rudder surface of the aircraft model is equipped with a non-contact Hall effect sensor, and the feedback signal of the rudder surface angle is uploaded to the flight control computer; An inertial sensor is installed in the aircraft model to measure the pitch angle, roll angle, pitch angular velocity, roll angular velocity, yaw angular velocity, X, Y, and Z axis acceleration of the aircraft model; The wind vane sensor is installed on the head of the aircraft, the wind vane drives the encoder, and the flight control computer collects the A, B, and Z phase signals of the incremental encoder, and calculates the angle of attack and sideslip angle of the aircraft; the pressure measurement is embedded in the head of the aircraft In the wind tunnel, measure the pressure hole pressure at each angle of attack and sideslip angle in advance, and store it in the memory of the flight control computer. During the flight test, the flight control computer collects the voltage signal of the pressure sensor, and solves it through the pressure interpolation of each pressure hole. Calculate the angle of attack and sideslip angle of the aircraft, and finally obtain accurate data by combining the two measurement methods through the Kalman filter algorithm; The master and slave sensors of the spatial position sensor are respectively installed around the wind tunnel support device, and the ultra-wideband wireless carrier communication technology is used to measure the space position of the aircraft model. The label sensor is installed inside the model, and the ultra-wideband wireless carrier signal sent by the label sensor will It is received from the sensor, decodes the angle and time difference information of the ultra-wideband wireless carrier signal from the sensor, and then transmits these data to the main sensor, and solves the spatial position through the arrival angle positioning algorithm and the arrival time difference positioning algorithm. The flight control computer uses TCP/IP The data collected by the main sensor is obtained, and the X, Y, and Z axis spatial positions of the aircraft are calculated. 2. a kind of wind tunnel model free flight test flight control system based on embedded controller according to claim 1, is characterized in that: described parameter configuration module function comprises: storage path and frequency configuration, main control computer and Flight control computer transmission rate configuration, flight control law parameter configuration and sensor type selection; the functions of the equipment calibration module include: reset of each sensor system and linear calibration of the rudder surface angle; the control command module includes: attitude and space Position open-loop control and closed-loop control switching operations, curve excitation control and program and remote control switching operations; the data display module functions include: aircraft model attitude angle, spatial position, rudder surface angle and engine thrust display. 3. a kind of wind tunnel model free flight test flight control system based on embedded controller according to claim 1, is characterized in that: flight control computer software comprises network communication module, configuration file module, data acquisition module, position and attitude Control module, hardware drive module, and data storage module, wherein the functions of the network communication module include: main control computer and flight control computer command/data communication; the functions of the configuration file module include: storage path and frequency configuration file, main control computer and flight control Computer transmission rate configuration file, flight control law parameter configuration file, etc.; data acquisition module functions include: data acquisition of wind vane sensors, pressure sensors, non-contact Hall effect sensors, etc.; position and attitude control module functions include: data acquisition module acquisition Data, perform data filtering, and calculate the steering gear rudder surface actuation command, engine actuation command, and thrust vector device actuation command through the control law. And the data of engine analysis and execution; the functions of the data storage module include: storage of test data during the flight test. 4. a kind of wind tunnel model free flight test flight control system based on embedded controller according to claim 1, is characterized in that: described flight control computer collects airborne sensor data, including: angle of attack, sideslip Angle, pitch angle, roll angle, pitch angular velocity, roll angular velocity, yaw angular velocity and X, Y, Z axis acceleration data are used to control the aircraft attitude control, X, Y, Z axis spatial position data are used to control the aircraft position control, The flight control law algorithm calculates the control variables of the steering gear rudder surface and the power system according to the airborne sensor data. The calculated control variables need to be converted into PWM signals by the flight control computer, and finally the steering gear rudder surface and power are controlled by the PWM signals. system, power system and transmit the speed signal to the flight control computer through PWM signal.

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