Fast mirror-based airborne platform vibration simulation system and method

Abstract

The application provides a kind of airborne platform vibration simulation system and method based on fast mirror, belongs to optical testing and environmental simulation technical field.System includes laser source, beam shaping and beam expanding unit, vibration simulation unit, focusing lens, target surface and diagnostic equipment arranged in turn along optical path;Vibration simulation unit includes fast mirror and vibration control subsystem, fast mirror is used to receive jitter instruction and simulate light beam pointing jitter through high-frequency micro-amplitude deflection, vibration control subsystem pre-stores a variety of typical vibration spectrum, and can generate disturbance control signal with specified frequency, amplitude, harmonic and random characteristics.Through diagnostic equipment, record and compare with ideal steady state for analysis.The application uses fast mirror to replace traditional mechanical vibration table, realizes lightweight, high-precision, programmable vibration simulation, and is suitable for performance evaluation and optimization of airborne platform optical system.

Description

Technical Field

[0001] This invention relates to the fields of optical testing, precision optoelectronic control and environmental simulation technology, and more specifically, to an airborne platform vibration simulation system and method based on a fast-reflecting mirror. Background Technology

[0002] In airborne applications such as high-energy laser weapons, photoelectric detection and tracking, and free-space optical communication, the aircraft platform is affected by various factors such as engine vibration, aerodynamic turbulence, and maneuvering overload during flight. This causes problems such as beam pointing jitter, beam dispersion, and energy attenuation in the onboard optical system, which seriously affects the system's aiming accuracy and strike effectiveness.

[0003] Traditional vibration simulation methods primarily employ mechanical vibration tables, which physically excite the entire optical system by mounting it on the table. However, this method has several drawbacks: First, large optical systems are bulky and heavy, making them difficult to install and operate stably on vibration tables; second, mechanical vibration tables have a limited frequency response range, making it difficult to accurately reproduce complex high-frequency, small-amplitude vibration spectra; and third, the vibration table itself introduces additional inertial interference, affecting the realism of the simulation.

[0004] Therefore, there is an urgent need for a system and method that can accurately, flexibly, and cost-effectively simulate the vibration characteristics of airborne platforms in a laboratory environment, so as to effectively evaluate and optimize the performance of optical systems under different vibration conditions. Summary of the Invention

[0005] (a) Technical problems to be solved The technical problem this invention aims to solve is that existing mechanical vibration table simulation methods cannot accurately reproduce the vibration of airborne platforms with high frequency, small amplitude, and complex spectral characteristics, and are difficult to adapt to the ground testing requirements of large optical systems. There is a lack of a lightweight, high-precision, and programmable vibration simulation method.

[0006] (II) Technical Solution To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides an airborne platform vibration simulation system based on a fast-reflecting mirror, comprising a laser source, a beam shaping and expanding unit, a vibration simulation unit, a focusing lens, a target surface, and a diagnostic device arranged sequentially along the optical path; the vibration simulation unit includes a fast-reflecting mirror and a vibration control subsystem; the fast-reflecting mirror is disposed in the optical path and is used to receive jitter commands from the vibration control subsystem, and to simulate beam pointing jitter caused by external vibration and platform disturbance through high-frequency, micro-amplitude deflection; the vibration control subsystem is electrically connected to the fast-reflecting mirror and includes a control computer and a drive module; the vibration control subsystem has multiple typical vibration spectra pre-stored and generates disturbance control signals with specified frequencies, amplitudes, harmonics, and random characteristics according to requirements to drive the fast-reflecting mirror to reproduce the target vibration characteristics; the diagnostic device is used to record the beam pointing, beam distribution, energy changes, and dynamic characteristics of the light spot on the target surface.

[0007] In the above technical solution, a fast-reflecting mirror replaces the traditional mechanical vibration table, avoiding the problem of large optical systems being difficult to install on the vibration table. The high-frequency response and micro-radian-level angular resolution of the fast-reflecting mirror can accurately simulate the high-frequency, small-amplitude vibrations of the airborne platform, compensating for the low frequency response of the mechanical vibration table. The vibration control subsystem pre-stores multiple typical vibration spectra, which can be quickly switched according to different aircraft models and flight states, simulating various vibration environments without changing hardware, significantly improving testing efficiency. The diagnostic equipment, in conjunction with the target surface, can record dynamic characteristics such as beam pointing, spot distribution, and energy changes in real time, providing a data foundation for subsequent beam control algorithm verification and system performance optimization.

[0008] Preferably, the fast-reflecting mirror is a biaxial piezoelectric ceramic driven fast-reflecting mirror. The biaxial design allows the fast-reflecting mirror to deflect independently in two orthogonal directions, X and Y, enabling a more realistic simulation of the complex vibrations of an airborne platform, rather than single-dimensional jitter. The piezoelectric ceramic drive features millisecond-level response time, nanometer-level displacement resolution, and no mechanical friction, making it particularly suitable for reproducing high-frequency, small-amplitude vibrations and ensuring the fidelity of the analog signal.

[0009] Preferably, the vibration control subsystem applies the disturbance control signal to the fast reflector in an open-loop manner. Open-loop control does not rely on feedback sensors, eliminating phase lag caused by sampling, calculation, and output in a closed-loop system. This allows the fast reflector to instantly follow the preset disturbance signal, making it particularly suitable for simulation tests requiring precisely known disturbances. It eliminates the need for additional position detection sensors and closed-loop controllers, reducing hardware costs and debugging difficulty, while simultaneously improving system reliability.

[0010] Preferably, the diagnostic device includes a high-speed camera and / or an infrared thermal imager. The high-speed camera records the positional trajectory of the light spot on a sub-millisecond scale for analyzing the beam jitter spectrum; the infrared thermal imager measures the energy concentration and temperature distribution of the light spot to assess the energy dispersion effect caused by vibration. Both devices cover the visible and infrared bands respectively, providing dual data on the light spot morphology and thermal characteristics, making the assessment of the impact of vibration on system performance more comprehensive.

[0011] Secondly, the present invention also provides a method for conducting vibration simulation tests using the aforementioned airborne platform vibration simulation system based on a fast-reflecting mirror, comprising the following steps: S1. Set the simulation conditions and input the vibration spectrum characteristic parameters of the target vibration, including frequency, amplitude, harmonic components and random disturbances. S2. The vibration control subsystem generates a dynamic disturbance control signal that matches the target vibration based on the set simulated working conditions. S3. Apply the dynamic disturbance control signal to the fast-reflecting mirror; S4. Turn on the laser source. After the laser beam passes through beam shaping and beam expansion in sequence, it is reflected by the fast-reflecting mirror and introduced into pointing jitter, forming a laser beam carrying a platform vibration effect. S5. The laser beam carrying the platform vibration effect, after passing through the focusing lens, forms a rapidly moving, randomly moving, dynamic jittering spot on the target surface, simulating platform vibration. S6. Record the beam direction, spot distribution, energy change and dynamic characteristics through diagnostic equipment, and compare and analyze them with the ideal steady-state beam to complete the vibration environment simulation and system performance evaluation.

[0012] In the above technical solution, the method forms a complete chain from setting the operating conditions to analyzing the results. It can reproduce any specified vibration spectrum under laboratory conditions, enabling standardized and repeatable quantitative evaluation of the performance of optical systems in simulated vibration environments. Through preset vibration spectra and automated control, a large amount of dynamic data can be obtained in a single test, significantly shortening the research and development cycle.

[0013] Preferably, in step S2, the vibration control subsystem retrieves the corresponding vibration spectrum from its internally stored vibration spectrum library to generate the dynamic disturbance control signal.

[0014] Preferably, the fast-reflecting mirror deflects in an open-loop manner under the drive of the dynamic disturbance control signal to actively apply a controllable disturbance.

[0015] (III) Beneficial Effects The above-described technical solution of the present invention has at least the following advantages: 1. This invention uses a fast-reflecting mirror as the core actuator. Its high-frequency response and micro-radian angular resolution enable precise simulation of high-frequency, small-amplitude vibrations of airborne platforms, overcoming the shortcomings of traditional mechanical vibration tables, such as low frequency response and large size. It can be used for environmental adaptability testing in various fields, including optical imaging, beam transmission, and laser damage effect monitoring, and possesses significant engineering application value.

[0016] 2. In this invention, the vibration control subsystem has a built-in library of various typical vibration spectra, which can be quickly switched according to different aircraft models, flight states, weather conditions and other operating conditions. It can simulate various vibration environments without changing hardware, which greatly improves the flexibility and efficiency of testing. The system provided by this invention has a compact structure and is easy to integrate. It can be directly connected to the existing optical test optical path without major modification to the entire optical system, saving testing costs and R&D cycle. It can be used independently or expanded into a multi-environmental effect composite simulation system.

[0017] 3. In this invention, the fast-reflecting mirror adopts an open-loop control method, which avoids the phase delay and stability problems caused by closed-loop feedback. This enables the fast-reflecting mirror to quickly and accurately follow the preset disturbance signal. It is particularly suitable for simulation test scenarios that require the active application of known disturbances. It is different from the traditional fast-reflecting mirror for correction and image stabilization purposes. The technical path is clear and the versatility is strong.

[0018] 4. The system provided by this invention, in conjunction with high-precision diagnostic equipment such as high-speed cameras and infrared thermal imagers, can capture the dynamic behavior of light spots in real time, accurately map the impact of vibration on beam direction, light spot distribution and system performance, and quantify vibration interference effects separately under controllable conditions, providing refined data support for the design of optical system image stabilization, aiming stabilization and anti-interference. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the airborne platform vibration simulation system based on a fast-reflecting mirror provided in an embodiment of the present invention.

[0021] Figure 2 This is a comparison diagram of the spot effects of an ideal beam and a vibration-simulated beam provided in an embodiment of the present invention.

[0022] The labels for the attached figures are as follows: 1. Laser source; 2. Beam shaping and expanding unit; 3. Fast reflection mirror; 4. Vibration control subsystem; 5. Focusing lens; 6. Target surface; 7. Diagnostic equipment. Detailed Implementation

[0023] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0024] The specific implementation of the present invention will be described in more detail below with reference to specific embodiments: Reference Figure 1 This embodiment provides an airborne platform vibration simulation system based on a fast-reflecting mirror, including a laser source 1, a beam shaping and expanding unit 2, a vibration simulation unit, a focusing lens 5, a target surface 6, and a diagnostic device 7 arranged sequentially along the optical path.

[0025] The laser source 1 is used to generate a high-energy laser beam. In this embodiment, a continuous / pulsed fiber laser with a wavelength of 1 μm and adjustable power is used. The beam shaping and expanding unit 2 consists of a set of lenses, used to expand the diameter of the laser beam to the required size and improve the beam quality, making it close to a plane wavefront.

[0026] The vibration simulation unit is the core component of this invention, comprising a fast-reflecting mirror 3 and a vibration control subsystem 4. The fast-reflecting mirror 3 is a biaxial piezoelectric ceramic driven fast-reflecting mirror with a deflection range of ±8 mrad and a bandwidth greater than 500 Hz. The vibration control subsystem 4 includes an industrial control computer and a matching piezoelectric ceramic drive module. The control computer is pre-installed with a vibration spectrum database covering various measured vibration data and various random vibration spectra.

[0027] The vibration control subsystem 4 adopts an open-loop working mode: the control computer retrieves the corresponding vibration spectrum from the database according to the simulated operating parameters (such as flight altitude, Mach number, wingtip position, etc.) input by the user, generates a digital disturbance signal, and then outputs it to the piezoelectric ceramic driver of the fast reflector 3 through D / A conversion and high voltage amplifier, so that the fast reflector 3 deflects according to the preset frequency, amplitude and waveform.

[0028] Focusing lens 5 is used to focus the jittered laser beam onto target surface 6. Target surface 6 is an aluminum alloy plate used to display the laser spot. Diagnostic device 7 includes a high-speed camera and an infrared thermal imager, used to record the dynamic characteristics of the laser spot in the visible light band and the energy distribution in the infrared band, respectively.

[0029] During operation, the laser emitted from laser source 1 is collimated into a beam after passing through beam shaping and expanding unit 2, and then incident on the surface of fast reflector 3. Driven by vibration control subsystem 4, fast reflector 3 performs high-frequency, micro-amplitude oscillations, causing periodic changes in the direction of the reflected beam, thereby simulating beam pointing jitter caused by airborne platform vibration. The laser beam carrying jitter information is converged by focusing lens 5, forming a rapidly moving dynamic spot on target surface 6. High-speed camera and infrared thermal imager simultaneously acquire information such as the position, shape, size, and brightness of the spot, and transmit the data to the host computer for analysis and processing. The data is compared with the static spot under ideal vibration-free conditions to assess the degree of impact of vibration on system performance.

[0030] Example 2 Reference Figure 2 This embodiment provides a method for conducting vibration simulation tests using the above system, including the following steps: Step S1: The operator sets the simulated operating conditions through the host computer software. For example, the simulated operating conditions are a hovering attack by a drone at an altitude of 150m with moderate intensity body vibration (main frequency 30Hz, with 50Hz and 80Hz harmonics).

[0031] Step S2: The vibration control subsystem 4, based on the set operating conditions, matches the closest vibration spectrum data from its internally stored vibration spectrum library and performs interpolation calculations to generate a dynamic disturbance control signal sequence. Specifically, the control software built into the vibration control subsystem 4 retrieves the corresponding random vibration spectrum from the vibration spectrum library and discretizes the vibration spectrum into several sinusoidal components according to frequency. The data sources in this vibration spectrum library include actual environmental test measurements and numerical reconstruction based on known power spectral density; among them, the numerical reconstruction method uses the power spectral density function obtained from actual measurement or theoretical analysis as input conditions, and adopts a spectrum reconstruction algorithm based on inverse fast Fourier transform (IFFT) to directly generate a random time-domain vibration signal that conforms to the target spectral characteristics. Let the frequency of the i-th frequency component be f. i The corresponding power spectral density value is S(f i If the frequency interval is Δf, then the amplitude A of this component is... i From the formula Determined, phase φ i Randomly generated within the range of 0 to 2π. All components are synthesized into a time-domain voltage signal. Where N is the number of discrete frequency points and t is time, the signal is converted from digital to analog and then applied to the two-axis piezoelectric ceramic actuator of the fast reflector 3, thereby driving the fast reflector 3, causing the fast reflector 3 to generate a high-frequency micro-amplitude deflection based on the signal, so as to simulate the beam pointing jitter caused by the vibration of the motor platform.

[0032] Step S3: The control signal sequence is converted into an analog voltage by a D / A converter, amplified by a high-voltage amplifier, and applied to the biaxial piezoelectric ceramic of the fast reflector 3.

[0033] Step S4: Turn on the laser source 1. After passing through the beam shaping and expanding unit 2, the laser beam illuminates the fast reflector 3. The fast reflector 3 deflects according to the control signal, causing the reflected beam to produce directional jitter consistent with the preset vibration spectrum.

[0034] Step S5: After passing through the focusing lens 5, the jittery beam forms a dynamic spot with a diameter of approximately 2 mm on the target surface 6. Because the deflection frequency of the fast-reflecting mirror 3 is as high as several hundred hertz, the spot moves rapidly and randomly on the target surface, appearing to the naked eye as a blurry bright area (e.g., as shown in the image). Figure 2 (As shown in b).

[0035] Step S6: A high-speed camera continuously captures images of the light spot, while an infrared thermal imager simultaneously records the temperature distribution of the light spot. After the acquired image data is transmitted to the host computer, image processing algorithms extract parameters such as the centroid coordinates, spot radius, and energy concentration of the light spot in each frame, and statistically analyze their changes over time. These parameters are then compared with theoretically calculated ideal steady-state light spots (e.g., such as...). Figure 2 By comparing the laser beam jitter amplitude, frequency response curve, and percentage of energy loss (as shown in Figure a), key indicators such as beam jitter amplitude, frequency response curve, and percentage of energy loss are obtained, thereby quantitatively evaluating the performance of the laser system under simulated vibration environment.

[0036] Figure 2 The diagrams show a comparison of the laser spot effects of the ideal beam and the vibration-simulated beam. As shown in part a, when the vibration simulation unit is turned off, the laser forms a stable and regular Gaussian spot, quickly melting through the regular small hole. As shown in part b, when the vibration simulation unit is turned on, the laser spot moves rapidly and randomly, the energy cannot be stably concentrated, a large area of ​​uneven temperature rise forms on the target surface, the center temperature decreases, the melting time is significantly prolonged, and the damaged area expands and becomes irregular.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A vibration simulation system for an airborne platform based on a fast-reflecting mirror, characterized in that, It includes a laser source, a beam shaping and expanding unit, a vibration simulation unit, a focusing lens, a target surface, and diagnostic equipment arranged sequentially along the optical path; the vibration simulation unit includes a fast-reflecting mirror and a vibration control subsystem. A fast-reflecting mirror is positioned in the optical path to receive jitter commands from the vibration control subsystem and simulate beam pointing jitter caused by external vibrations and platform disturbances through high-frequency, micro-amplitude deflection. The vibration control subsystem is electrically connected to the fast-reflecting mirror and includes a control computer and a drive module. The vibration control subsystem has multiple typical vibration spectra pre-stored and generates disturbance control signals with specified frequencies, amplitudes, harmonics, and random characteristics as needed to drive the fast-reflecting mirror to reproduce the target vibration characteristics. The diagnostic device is used to record the beam pointing, beam distribution, energy changes, and dynamic characteristics of the beam on the target surface.

2. The airborne platform vibration simulation system based on a fast-reflecting mirror as described in claim 1, characterized in that, The fast-reflecting mirror is a biaxial piezoelectric ceramic driven fast-reflecting mirror.

3. The airborne platform vibration simulation system based on a fast-reflecting mirror as described in claim 1, characterized in that, The vibration control subsystem applies disturbance control signals to the fast-reflecting mirror in an open-loop manner.

4. The airborne platform vibration simulation system based on a fast-reflecting mirror as described in claim 1, characterized in that, The diagnostic equipment includes a high-speed camera and / or an infrared thermal imager.

5. A method for conducting vibration simulation tests using an airborne platform vibration simulation system based on a fast-reflecting mirror as described in any one of claims 1 to 4, characterized in that, Includes the following steps: S1. Set the simulation conditions and input the vibration spectrum characteristic parameters of the target vibration, including frequency, amplitude, harmonic components and random disturbances. S2. The vibration control subsystem generates a dynamic disturbance control signal that matches the target vibration based on the set simulated working conditions. S3. Apply the dynamic disturbance control signal to the fast-reflecting mirror; S4. Turn on the laser source. After the laser beam passes through beam shaping and beam expansion in sequence, it is reflected by the fast-reflecting mirror and introduced into pointing jitter, forming a laser beam carrying a platform vibration effect. S5. The laser beam carrying the platform vibration effect, after passing through the focusing lens, forms a rapidly moving, randomly moving, dynamic jittering spot on the target surface, simulating platform vibration. S6. Record the beam direction, spot distribution, energy change and dynamic characteristics through diagnostic equipment, and compare and analyze them with the ideal steady-state beam to complete the vibration environment simulation and system performance evaluation.

6. The method as described in claim 5, characterized in that, In step S2, the vibration control subsystem retrieves the corresponding vibration spectrum from its internally stored vibration spectrum library to generate the dynamic disturbance control signal.

7. The method as described in claim 5, characterized in that, The fast-reflecting mirror deflects in an open-loop manner under the drive of the dynamic disturbance control signal to actively apply a controllable disturbance.

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