航空光电稳定平台扰动抑制技术的研究

	航空光电稳定平台扰动抑制技术的研究
	李贤涛
学位类型	博士
导师	张葆
	2014-07
学位授予单位	中国科学院大学
学位专业	光学工程
摘要	航空光电稳定平台广泛应用于敌情侦察、目标定位、打击校射和效果评估等领域。其中，视轴的稳定精度是衡量其性能的一项关键指标，稳定精度越高，航空光电稳定平台成像越清晰，信息获取越准确。然而在实际工作过程中，飞机飞行姿态的不断变化，发动机的振动、气流扰动等因素均会导致驱动电机的输出力矩不能够完全准确地驱动框架，如此一来，便使得视轴不能按照期望的方式稳定在目标位置。由此可见，如何提高系统的扰动抑制能力，是提高航空光电稳定平台视轴稳定精度的关键技术之一。本文对两轴四框架航空光电稳定平台中的扰动作用原理进行深入研究，并提出了“主动抗扰”与“被动抗扰”相结合的“引导型”自抗扰控制策略对系统中的扰动进行抑制。本文研究的主要内容如下：1. 本文首先根据两轴四框架光电稳定平台的结构，从系统运动学—动力学耦合方程出发，提出了减小框架间耦合的具体方法。从机械结构优化设计的角度，对两轴四框架光电稳定平台的控制系统提出了设计要求。2. 对平台中每一框架均进行了电流环设计，以保证电机的输出力矩恒定。并结合航空光电稳定平台的工作特点，对系统中的各种干扰进行综合分析，并按照其作用位置将其分为模型干扰、电机干扰、力矩干扰等三类，以此为依据，采用“等效扰动电压”的方式建立了系统的被控模型，如此一来，不仅避免了各种扰动力矩复杂的建模过程，同时为“主动抗扰”策略的应用奠定了基础。3.在速度稳定回路中，分别采用平方滞后控制器和平方PI控制器，显著地提高了低频段的开环增益，取得了令人满意的“被动抗扰”效果。详细论述了采用传统控制策略时，系统扰动隔离度受机械谐振频率严格限制的原因，进而引入快速反射镜，从结构设计的角度进一步发挥了传统控制策略对扰动的抑制能力。同时，在不改变机械结构单纯依靠控制策略的角度，提出了二级“引导型”自抗扰控制器，以“主动”与“被动”相结合的方式进一步对系统中的扰动进行抑制，极大程度的提高了系统的扰动隔离度。4. 在飞行模拟转台中测试二级“引导型”自抗扰控制器对2.5Hz以内任意频率扰动的抑制能力，并与目前航空光电稳定平台中常用的平方滞后超前校正方法进行对比。实验结果表明：相比于传统的平方滞后控制器，采用“引导型”自抗扰控制器，系统的扰动隔离度至少提高8.52dB，且随着扰动频率大于0.5Hz，该控制器的扰动抑制能力更为明显，扰动隔离度最多提高了13.06dB；同时，“引导型”自抗扰控制器具有很强的鲁棒性，允许被控对象参数在15%的范围内任意变化；除此之外，在高低温和振动冲击等可靠性实验中，“引导型”自抗扰控制器也表现出至少优于传统平方滞后控制器1倍以上的性能，充分体现了“引导型”自抗扰控制器的优越性，对提高航空光电稳定平台控制系统的抗扰动性能具有较高的实用价值。
其他摘要	Aerial photoelectrical stabilized platform is widely used in the zone of enemy investigation, target location, attack collation and effect evaluation. Optic axis stability is an important metric for charactering the stable plan. With higher optic axis stability, the accuracy and image quality of the plan will consequently raise. Nevertheless, limited by the rigid body motion of the plane, engine vibration and turbulence of the airflow, the output moment of the electric-motor cannot be totally transferred to the frame and this leads to the deviation from the perfect location of pointing model.so we place significance on the robust of the plan system.In this article, after processing the specification of the turbulence in theory, we degrade the restrain strategy into two individual parts: the active restrain and the passive one and this paper will be organized as follows.To begin with, according to the mechanical structure of the stable plan, we develop a method from the motion and dynamic equations to restrain the coupling among the frames. Thus, the optimize design of the plan provides a requirement for the control system of the plan. In the second place, we design the current loop separately for every frame, in order to provide a smooth moment output.The analytical determination that how the sensitivity for the various kinds of turbulence moment influences the plan pointing accuracy will be received.Based on the current loop, we investigate the control current which specifies both the turbulence moment and model error. Modeling in this way, for one thing, we can understand the error model more easily.For another, the construction of active control strategy will benefits from it.In speed stability loop, the traditional square lag-lead compensation method and square PI controller can provide adequate passive restraint and improve the performance of the controller in the low part of the frequency domain. The two-stage ADRC whose estimated value of disturbance is oriented by target value, combines the active and passive strategy,is involved for contribution to the iso-vibration of the system and optic axis stability.Lastly, an experiment was performed to test the disturbance rejection performance of the ADRC based on current loop when the speed disturbance is from 0.1Hz to 2.5Hz as compared with the traditional square lag-lead compensation method. Experiment results show that ADRC can reduce the disturbance error 8.52dB at least. And the isolation degree of disturbance is improved obviously when the perturbation frequency is more than 0.5Hz, the best isolation degree of disturbance is increased 13.06dB. And the ADRC have strong robustness, allowing the range of system parameters to change in 15%. In addition, the disturbance rejection performance of the ADRC whose estimated value of disturbance is oriented is improved more than one time in the temperature test and vibration experiment.In conclusion, the ADRC whose estimated value of disturbance is oriented satisfies the performance requirements of aerial photoelectrical stabilized platform and have higher practical value.
语种	中文
文献类型	学位论文
条目标识符	http://ir.ciomp.ac.cn/handle/181722/41430
专题	中科院长春光机所知识产出
推荐引用方式 GB/T 7714	李贤涛. 航空光电稳定平台扰动抑制技术的研究[D]. 中国科学院大学,2014.

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