光电吊舱隔振系统设计及试验研究

发布时间：2018-12-07 20:02

【摘要】：随着民用无人机技术的发展,工业级无人机广泛的应用于地图测绘、灾害搜救、电力巡线等领域,光电吊舱作为无人机上的主要有效载荷得到越来越多的关注。光电吊舱工作时不可避免的受到发动机、无人机速度及姿态变化产生的振动和滑起滑降、弹射伞降的起飞着陆冲击等一系列复杂的振动影响。为提高光电吊舱的成像质量,必须对振动加以控制。振动控制可分为主动控制和被动控制,在小型无人机上搭载光电吊舱要求隔振系统总体质量低、结构简单、可实现性强且经济适用,因此本课题针对机载光电吊舱的实际使用工况,研制一套适用于工业级无人机光电吊舱的被动隔振系统。首先进行了无人机飞行振动环境试验,获得光电吊舱实际工作阶段:无人机在一定的飞行高度和发动机转速条件下的振动信号,通过数据处理获得光电吊舱隔振器安装位置处三个方向的时域特征和频域特征,为隔振系统设计提供依据。然后建立了光电吊舱隔振系统多自由度模型,根据数学模型和隔振理论指导隔振器的空间布局及相对位置、隔振器的三向刚度及阻尼值和隔振系统框架结构的设计,以合理配置光电吊舱隔振系统的六个自由度固有频率。最终应用了一种小型干摩擦高阻尼金属隔振器。在此基础上建立了光电吊舱隔振系统动力学模型和隔振系统有限元模型,利用Adams/Vibration模块获得光电吊舱隔振系统的模态信息、耦合率、频率响应曲线和随机振动响应曲线,结果显示理论计算和仿真分析计算的固有频率最大误差为1.27%;利用Workbench软件进行了隔振系统框架的模态分析、强度分析和安装骨架的动刚度分析,检验隔振系统结构的适应性和可靠性。最后进行了光电吊舱隔振系统振动台试验包括正弦扫频试验和随机振动试验,获得隔振系统的固有频率、共振点放大倍数和振动衰减的情况,结果显示在激振力频率92.5Hz处的传递率竖直方向为0.2,水平方向为0.3;理论计算和振动试验的固有频率误差竖直方向为2.81%,水平方向为10.5%;隔振系统在0-250Hz频率范围内的隔振效率竖直方向为63.8%,水平方向为55.5%;无人机飞行实测获得的高质量图像也验证了隔振系统的隔振性能良好。本文研究工作具有实际工程意义同样可供机载被动隔振系统设计参考。
[Abstract]:With the development of civilian UAV technology, industrial UAV is widely used in map mapping, disaster search and rescue, power survey and other fields. As the main payload of UAV, photoelectric pods have been paid more and more attention. The photoelectric pods are inevitably affected by a series of complex vibration, such as the engine, the vibration caused by the change of the UAV's speed and attitude, the sliding and sliding, the take-off and landing impact of the ejection parachute, and so on. In order to improve the imaging quality of photoelectric pods, vibration must be controlled. Vibration control can be divided into active control and passive control. Carrying photoelectric pods on a small UAV requires low overall quality, simple structure, strong realizability and economic applicability. Therefore, a passive vibration isolation system suitable for the photoelectric pods of industrial UAV is developed in accordance with the actual operating conditions of the airborne optoelectronic pods. Firstly, the vibration environment test of UAV flight is carried out, and the actual working stage of photoelectric pods is obtained: the vibration signals of UAV under certain flight altitude and engine speed are obtained. Through the data processing, the time domain and frequency domain characteristics of the three directions of the installation position of the photoelectric pod isolator are obtained, which provides the basis for the design of the vibration isolation system. Then the multi-degree-of-freedom model of the photoelectric pod vibration isolation system is established. According to the mathematical model and vibration isolation theory, the spatial layout and relative position of the isolator, the three-dimensional stiffness and damping value of the isolator and the design of the frame structure of the isolation system are guided. The natural frequencies of six degrees of freedom of the optoelectronic pod vibration isolation system are reasonably configured. Finally, a small dry friction high damping metal vibration isolator is applied. On this basis, the dynamic model and the finite element model of the photoelectric pod vibration isolation system are established. The modal information, coupling rate, frequency response curve and random vibration response curve of the photoelectric pod vibration isolation system are obtained by using the Adams/Vibration module. The results show that the maximum error of natural frequency between theoretical calculation and simulation analysis is 1.27. The modal analysis, strength analysis and dynamic stiffness analysis of the frame of vibration isolation system are carried out by using Workbench software to verify the adaptability and reliability of the structure of the isolation system. Finally, the vibration table test of the photoelectric pod vibration isolation system including sinusoidal sweep frequency test and random vibration test is carried out. The natural frequency of the isolation system, the magnification of the common vibration point and the vibration attenuation are obtained. The results show that the vertical direction is 0.2 and the horizontal direction is 0.3 at the excitation frequency 92.5Hz. The vertical direction of natural frequency error in theoretical calculation and vibration test is 2.81, the horizontal direction is 10.5, the vertical direction of isolation efficiency in 0-250Hz frequency range is 63.8 and the horizontal direction is 55.5. The high-quality images obtained from UAV flight test also verify the good isolation performance of the vibration isolation system. The research work in this paper is of practical engineering significance and can be used as a reference for the design of airborne passive vibration isolation system.
【学位授予单位】：中国科学院长春光学精密机械与物理研究所
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB535.1

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