航空光电稳定平台扰动抑制技术的研究

发布时间：2018-08-08 15:05

【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。
[Abstract]:Aerial photoelectricity stabilization platform is widely used in enemy reconnaissance, target positioning, attack and effect evaluation. The stability accuracy of the view axis is a key index to measure its performance. The higher the stability accuracy is, the clearer the aerial photostable platform imaging is, the more accurate the information is obtained. However, in the actual working process, the flight posture of the aircraft. The constant change of the state, the vibration of the engine, the turbulence of the airflow and other factors will cause the driving motor's output torque not to be able to drive the frame completely and accurately, so that the view axis can not be stabilized in the desired position in the desired way. Thus, how to improve the disturbance rejection ability of the system is to improve the aircraft photoelectric stabilization platform. One of the key techniques for the stability of the axis of view.
In this paper, the principle of disturbance in the two axis four frame aerial photoelectricity stabilized platform is studied, and the guided self disturbance rejection control strategy of active and passive anti-interference is proposed to suppress the disturbance in the system. The main contents of this paper are as follows:
1. firstly, based on the structure of the two axis and four frame photoelectric stable platform, the concrete method of reducing the coupling between the frames is proposed from the coupling equation of the system kinematics and dynamics, and the design requirements for the control system of the two axis and four frame photoelectric stable platform are put forward from the angle of the optimization design of the mechanical structure.
2. for each frame in the platform, the current loop is designed to ensure that the output torque of the motor is constant. Combined with the working characteristics of the aviation photoelectric stable platform, the various interference in the system is analyzed synthetically, and it is divided into three kinds, such as model interference, motor interference and moment interference according to its position, based on the "wait". The control model of the system is established in the way of disturbing voltage, which not only avoids the complex modeling process of disturbance torque, but also lays the foundation for the application of active disturbance rejection strategy.
3. in the speed stabilization loop, the square lag controller and the square PI controller are adopted respectively. The open loop gain of the low frequency section is greatly improved and the passive interference effect is satisfactory. The reason that the system disturbance isolation is strictly limited by the mechanical resonance frequency is discussed in detail when the traditional control strategy is adopted, and the fast reflection is introduced. The mirror, from the angle of structure design, further exerts the restraining ability of the traditional control strategy to the disturbance. At the same time, the two stage guided self disturbance rejection controller is put forward without changing the mechanical structure simply depending on the control strategy. It can further suppress the disturbance in the system with the combination of active and passive. The disturbance isolation of the system.
4. test the suppression ability of the two stage guided self disturbance rejection controller to the arbitrary frequency disturbance within 2.5Hz in the flight simulation turntable and compare with the usual square lag correction method in the current aerial photostabilization platform. The experimental results show that the guided self disturbance rejection controller is used compared to the traditional square hysteresis controller. The disturbance isolation of the system increases at least 8.52dB, and with the disturbance frequency greater than 0.5Hz, the disturbance rejection capability of the controller is more obvious, and the disturbance isolation degree is up to 13.06dB, and the guided auto disturbance rejection controller has strong robustness, allowing the parameters of the controlled object to change arbitrarily within the range of 15%; in addition, it is high. In the reliability experiments of low temperature and vibration shock, the "guided" self disturbance rejection controller shows the performance of at least 1 times more than the traditional square lag controller. It fully embodies the superiority of the "guided" self disturbance rejection controller and has a high practical value for improving the anti disturbance performance of the aero photoelectric stabilization platform control system.
【学位授予单位】：中国科学院研究生院(长春光学精密机械与物理研究所)
【学位级别】：博士
【学位授予年份】：2014
【分类号】：V241;TB535

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