Flight control system stability reserve test system and method

Abstract

The invention provides a flight control system stability reserve test system and method, and belongs to the field of flight control systems, and the test system comprises an iron bird test bench which is provided with a servo actuation system for controlling the motion of a control surface; the power supply system is used for supplying power to the flight control system; the ground oil source is used for providing a hydraulic source for the servo actuation system; the flight control computer is connected with the servo actuation system and is used for performing control surface control on the aircraft in a given flight state; the tester is connected with the flight control computer and the servo actuation system and is used for measuring, cutting off or injecting various signals transmitted by the flight control computer to the servo actuation system; the flight simulation system is connected to the tester, and the flight simulation system is used for carrying out aircraft dynamics simulation and generating a disturbance equation; and the frequency response analyzer is connected to the tester and is used for generating a frequency sweeping signal and performing frequency response analysis.

Description

Technical Field

[0001] The present application belongs to the field of flight control technology, and in particular relates to a flight control system stability reserve test system and method. Background Art

[0002] The flight control system stability reserve determines the stability of the flight control system. The stability reserve test is used to test the open-loop frequency domain characteristics of the flight control system (referred to as the flight control system), calculate the amplitude stability reserve and phase stability reserve, and evaluate the stability of the flight control system. The existing flight control system stability reserve test has problems such as cumbersome measurement process and poor measurement results. Summary of the invention

[0003] The purpose of the present application is to provide a flight control system stability reserve test system and method to solve or alleviate at least one problem in the background technology.

[0004] On the one hand, the technical solution of the present application is: a flight control system stability reserve test system, comprising:

[0005] An iron bird test bench, wherein the iron bird test bench is equipped with a servo actuation system for controlling the movement of the rudder surface;

[0006] Power supply system, used to provide power to the flight control system;

[0007] A ground oil source is used to provide a hydraulic source for the servo actuator system;

[0008] A flight control computer, the flight control computer is connected to the servo actuator system and is used to control the control surfaces of the aircraft under a given flight state;

[0009] A tester, the tester is connected to the flight control computer and the servo actuator system, and is used to measure, intercept or inject various signals transmitted by the flight control computer to the servo actuator system;

[0010] A flight simulation system, the flight simulation system is connected to the tester, and the flight simulation system is used to simulate aircraft dynamics and generate disturbance equations;

[0011] A frequency response analyzer is connected to the tester and is used to generate a frequency sweep signal and perform frequency response analysis.

[0012] Preferably, the flight simulation system is connected to the tester via an interface system, and the interface system is used to realize signal generation, signal conversion, signal acquisition and signal control.

[0013] Preferably, it also includes a flight test interface device, which is connected to the flight control computer and is used to monitor the status of the flight control system.

[0014] On the other hand, the present application provides a method for performing a flight control system stability reserve test using any of the flight control system stability reserve test systems described above, comprising:

[0015] Divide the test state according to the flight state, control law working mode, flight control system sensor state and longitudinal and lateral heading channels to determine the content of the stability reserve test;

[0016] Selecting corresponding disturbance equations according to different test contents, transmitting the disturbance equations to the aircraft through the flight simulation system, and setting the flight control system state according to the test contents;

[0017] A sine sweep signal is input into the flight simulation system through a frequency response analyzer, and the frequency response of the aircraft control surface output and the flight simulation system input is measured to obtain the amplitude stability reserve and phase stability reserve.

[0018] Preferably, the sinusoidal swept frequency signal is A·sin(2πft), wherein the amplitude A is set to multiple amplitudes for testing, and the optimal amplitude is selected from the multiple amplitudes A in order to maximize the flight control system's proximity to a linear system, so as to find the intersection of the amplitude-frequency curve and the 0dB line and the phase-frequency curve reaching -180° to determine the optimal frequency range.

[0019] Preferably, when performing the longitudinal stability reserve test, a sinusoidal swept frequency horizontal tail rudder surface translation signal is input into the flight simulation system through a frequency response analyzer, and the frequency response of the horizontal tail rudder surface translation output and the flight simulation system input is measured;

[0020] When conducting the lateral stability reserve test, the frequency response analyzer is used to input a sine swept horizontal tail rudder differential signal into the flight simulation system, and the frequency response of the horizontal tail rudder differential output and the flight simulation system input is measured;

[0021] When conducting a heading stability reserve test, a sinusoidal swept frequency rudder surface signal is input into the flight simulation system through a frequency response analyzer to measure the frequency response of the rudder surface output and the flight simulation system input.

[0022] The flight control system stability reserve test system and method provided in the present application can simulate the actual motion state of the aircraft on the ground, obtain the open-loop frequency domain characteristics of the flight control system through a closed-loop method, measure the amplitude stability reserve and phase stability reserve, and make a quantitative judgment on the stability of the flight control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solution provided by the present application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0024] Figure 1This is a schematic diagram of the flight control system stability reserve test principle in this application.

[0025] Figure 2 This is a schematic diagram of the flight control system stability reserve test system of this application.

[0026] Figure 3 This is a schematic diagram of the flight control system stability reserve test method of the present application.

[0027] Figure 4 It is a schematic diagram of the stable reserve test results according to an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0029] like Figure 1 The figure shows the principle diagram of the stability reserve test of the flight control system (referred to as the flight control system) to be implemented in this application. It is assumed that the flight control system is a linear control system with an inner loop and an outer loop (the aircraft equation used in the test is a small disturbance equation, and under low frequency conditions (0.1Hz~4Hz), the rudder loop, sensor, etc. can be approximately considered as a linear system). Figure 1 It can be seen that its open-loop transfer function G k for:

[0030] G k =[G 3 (S)*H 2 (S)*H 1 (S)+G 3 (S)*H 1 (S)]*G 2 (S)

[0031] In the formula, G 1 (S) is the outer loop control law, G 2 (S) is the inner loop control law, G 3 (S) is the controlled object, H 1 (S) is the inner ring sensor signal, H 2 (S) is the outer ring sensor signal;

[0032] When the flight control system is in a stable state, adding an excitation signal, we can get:

[0033] Y=[X*G 3 (S)*H 2 (S)*G 1 (S)+X*G 3 (S)*H 1 (S)]*G2 (S)

[0034] Where, Y is the displacement signal of the rudder surface before the excitation signal of the frequency response analyzer is superimposed, and X is the displacement signal of the rudder surface after the excitation signal of the frequency response analyzer is superimposed;

[0035] Right now:

[0036] Therefore, the open-loop transfer function of the flight control system is obtained by using a closed-loop method:

[0037] To this end, the present application provides a flight control system stability reserve test system and method to implement the above stability reserve test. As shown in Figure 2, the flight control system stability reserve test system provided by the present application includes:

[0038] An iron bird test bench 101, wherein the iron bird test bench 101 is equipped with a servo actuation system 104 for controlling the movement of the rudder surface, hydraulic pipes and accessories, etc.;

[0039] A power supply system 102, used to provide power to the flight control system;

[0040] A ground oil source 103 is used to provide a hydraulic source for the servo actuator system 104;

[0041] A flight control computer 103, which is connected to a servo actuator system 104 and is used to control the control surfaces of the aircraft on the iron bird test bench 101 under a given flight state;

[0042] A tester 105, which is connected to the flight control computer (FCC) 103 and the servo actuator system 104 through a test cable, and can measure, intercept or inject various signals transmitted from the flight control computer 103 to the servo actuator system 104;

[0043] A flight simulation system 108, which is connected to the tester 105 via an interface system 107, the flight simulation system 108 is used to simulate aircraft dynamics and generate small disturbance equations for controlling the aircraft, and the interface system 107 is used to realize functions such as signal generation, signal conversion, signal acquisition and signal control;

[0044] A frequency response analyzer 106, which is connected to the tester 105 and is used to generate a frequency sweep signal and perform frequency response analysis;

[0045] The flight test interface device (FTI) 109 is connected to the flight control computer 103 and is used to monitor the status of the flight control system.

[0046] like Figure 3 As shown, the present application provides a method for performing a stability reserve test based on the above-mentioned flight control system, the method comprising the following steps:

[0047] Step 1: Divide the test state according to the flight state, control law working mode, flight control system sensor state, and longitudinal / lateral / heading channels, and determine the content of the stability reserve test.

[0048] Tables 1 to 3 show the test conditions and test contents divided in this application.

[0049] Table 1 Longitudinal channel stability reserve test status

[0050]

[0051] Table 2 Transverse channel stability reserve test status

[0052]

[0053]

[0054] Table 3 Heading channel stability reserve test status

[0055]

[0056]

[0057] Step 2: Select the corresponding small disturbance equation according to different test contents, transmit the small disturbance equation to the aircraft through the flight simulation system 108, and set the flight control system state according to the test contents;

[0058] Step three, under a given flight state, a sine frequency sweep signal is input to the flight simulation system 108 through the frequency response analyzer 106, and the frequency response of the control surface output and the flight simulation system input is measured to obtain the amplitude stability reserve and the phase stability reserve, that is, the open-loop frequency characteristic, so as to determine whether the stability reserve of the flight control system meets the design requirements.

[0059] In the present application, the sinusoidal swept frequency signal is A·sin(2πft), wherein the amplitude A can be set to multiple amplitudes for testing, and the optimal amplitude is selected from the multiple amplitudes A in order to maximize the flight control system's proximity to a linear system, so as to find the intersection of the amplitude-frequency curve and the 0dB line and the phase-frequency curve reaching -180° to determine the optimal frequency range.

[0060] The specific contents of the method for performing stability reserve test of the flight control system of this application are as follows:

[0061] S1, select the small disturbance equation according to the longitudinal / lateral / heading channel, and set the frequency response analyzer excitation and acquisition position:

[0062] In the present application, the longitudinal small disturbance equation is selected for the longitudinal stability reserve test, and a sine swept horizontal tail rudder surface translation signal is input into the flight simulation system 108 through the frequency response analyzer 106 to measure the frequency response of the horizontal tail rudder surface translation output and the input of the flight simulation system 108; the lateral stability reserve test selects the lateral heading small disturbance equation, and a sine swept horizontal tail rudder surface differential signal is input into the flight simulation system 108 through the frequency response analyzer 106 to measure the frequency response of the horizontal tail rudder surface differential output and the input of the flight simulation system 108; the heading stability reserve test selects the lateral heading small disturbance equation, and a sine swept rudder surface signal is input into the flight simulation system 108 through the frequency response analyzer 106 to measure the frequency response of the rudder surface output and the input of the flight simulation system 108.

[0063] S2, power on the flight control system through the power supply system 102, and supply pressure through the ground oil source 103.

[0064] S3, the flight status, control law working mode, flight control system sensor failure / working status, etc. set by the flight simulation system 108 are injected into the flight control computer 103 through the tester 105 via the interface system 107.

[0065] S4, load the stability reserve small perturbation equation and run the flight simulation.

[0066] S5, monitoring the flight control system status through the flight test interface device 109 is correct.

[0067] S6, connecting the frequency response analyzer 106 to the tester 105, selecting a stable reserve template, setting the sweep amplitude and frequency, and starting the sweep.

[0068] S7, after the frequency sweep is completed, the frequency characteristic curve is obtained, and the data is tested, analyzed, recorded and saved.

[0069] S8, test the remaining test states.

[0070] like Figure 4 The figure shows a stability reserve test result in an embodiment of the present application. The amplitude-frequency characteristic curve and the phase-frequency characteristic curve measured by the stability reserve test are solid lines, and the amplitude-frequency characteristic curve and the phase-frequency characteristic curve obtained by simulation are dotted lines. The amplitude reserve measured in the test is 10.7353dB, and the phase reserve is 58.9625°, which meets the requirements of not less than 6dB and 45°.

[0071] The flight control system stability reserve test system and method provided in the present application can simulate the actual motion state of the aircraft in the ground state, obtain the open-loop frequency domain characteristics of the flight control system through a closed-loop method, measure the amplitude stability reserve and phase stability reserve, and make a quantitative judgment on the stability of the flight control system.

[0072] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A flight control system stability reserve test system, characterized in that: include: An iron bird test bench, wherein the iron bird test bench is equipped with a servo actuation system for controlling the movement of the rudder surface; Power supply system, used to provide power to the flight control system; A ground oil source is used to provide a hydraulic source for the servo actuator system; A flight control computer, the flight control computer is connected to the servo actuator system and is used to control the control surfaces of the aircraft under a given flight state; A tester, the tester is connected to the flight control computer and the servo actuator system, and is used to measure, intercept or inject various signals transmitted by the flight control computer to the servo actuator system; A flight simulation system, the flight simulation system is connected to the tester, and the flight simulation system is used to simulate aircraft dynamics and generate disturbance equations; A frequency response analyzer is connected to the tester and is used to generate a frequency sweep signal and perform frequency response analysis.

2. The flight control system stability reserve test system according to claim 1, characterized in that: The flight simulation system is connected to the tester via an interface system, and the interface system is used to realize signal generation, signal conversion, signal acquisition and signal control.

3. The flight control system stability reserve test system according to claim 1, characterized in that: It also includes a flight test interface device, which is connected to the flight control computer and is used to monitor the status of the flight control system.

4. A method for performing a flight control system stability reserve test using the flight control system stability reserve test system as claimed in any one of claims 1 to 3, characterized in that: include: Divide the test state according to the flight state, control law working mode, flight control system sensor state and longitudinal and lateral heading channels to determine the content of the stability reserve test; Selecting corresponding disturbance equations according to different test contents, transmitting the disturbance equations to the aircraft through the flight simulation system, and setting the flight control system state according to the test contents; A sine sweep signal is input into the flight simulation system through a frequency response analyzer, and the frequency response of the aircraft control surface output and the flight simulation system input is measured to obtain the amplitude stability reserve and phase stability reserve.

5. The method according to claim 4, characterized in that The sinusoidal swept frequency signal is A·sin(2πft), wherein the amplitude A is set to multiple amplitudes for testing, and the optimal amplitude is selected from the multiple amplitudes A in order to maximize the flight control system's proximity to a linear system, so as to find the intersection of the amplitude-frequency curve and the 0dB line and the phase-frequency curve reaching -180° to determine the optimal frequency range.

6. The method according to claim 4 or 5, characterized in that When conducting the longitudinal stability reserve test, the frequency response analyzer is used to input a sine swept horizontal tail rudder translation signal to the flight simulation system, and the frequency response of the horizontal tail rudder translation output and the flight simulation system input is measured; When conducting the lateral stability reserve test, the frequency response analyzer is used to input a sine swept horizontal tail rudder differential signal into the flight simulation system, and the frequency response of the horizontal tail rudder differential output and the flight simulation system input is measured; When conducting a heading stability reserve test, a sinusoidal swept frequency rudder surface signal is input into the flight simulation system through a frequency response analyzer to measure the frequency response of the rudder surface output and the flight simulation system input.

Images