【作者】 朱华征；

【导师】 范大鹏；

【作者基本信息】 国防科学技术大学 ， 机械工程， 2012， 博士

【摘要】 导引头伺服机构是精确制导武器的核心部件，其性能直接决定了精确制导武器的性能。精确制导武器不断提高的制导精度对导引头伺服机构的静动态性能提出了更高的要求。特性指标是导引头伺服机构静动态性能的衡量标准，如何提出合理的特性指标要求是导引头伺服机构研制的基础。研究影响导引头伺服机构性能的内在机械、传感、控制等因素，并有针对性的提出相应的解决方案是提高导引头伺服机构性能的基本途径。本文首先研究了成像导引头特性指标的设计问题；然后研究了两轴两框架导引头伺服机构的动力学耦合问题，分析了质量不平衡力矩和摩擦力矩因素对导引头伺服机构性能的影响；在此基础上，从工程应用的角度研究了几种适用于导引头伺服机构的补偿控制方法。本文的主要研究工作为：1.研究载体运动对光电成像系统成像质量的影响是合理确定稳定精度指标的基础。首先分析了动载体光电成像系统视轴抖动的来源；然后从几何光学的角度分析了载体运动与光电成像系统焦平面上图像运动的关系；最后从光电成像系统的调制传递函数、分辨率以及NIIRS三个方面分别研究了载体运动对光电成像系统成像质量的影响。从满足光电成像系统探测性能的角度出发，提出了稳定精度指标设计的理论依据。2.针对成像导引头搜索、跟踪和稳定等特性指标的设计问题，首先分析了导引头的主要工作原理，提出了导引头伺服系统应具有的技术指标；然后研究了搜索盲区与搜索速度的关系，结合像移对探测器探测性能的影响，给出了搜索速度指标应该满足的关系式；分析了目标最大视线角速度和目标跟踪算法的实时性对导引头最大跟踪速度的要求，提出了导引头最大跟踪速度指标的确定方法；提出了跟踪精度的确定方法，分析了影响跟踪精度的主要误差因素；结合载体运动对光电成像系统成像质量的影响与系统的具体功能需求，提出了稳定精度指标的设计方法。3.针对动力学耦合以及质量不平衡力矩对导引头伺服机构性能的影响问题，建立了直驱型两轴两框架导引头伺服机构的运动学模型，并采用基于动点的动量矩定理建立了其包含质量不平衡力矩的动力学模型；研究了弹体与导引头伺服机构以及导引头内外框架之间的动力学耦合问题，推导了实现结构优化设计的条件；最后通过运动学和动力学仿真分析，阐明了各种耦合力矩和质量不平衡力矩对导引头伺服机构特性的影响，为开展导引头伺服机构优化设计和扰动力矩控制方法研究奠定了基础。4.针对摩擦力矩对导引头伺服机构的影响问题，采用描述函数方法研究了摩擦力矩产生的运动耦合特性和摩擦力矩对系统频率特性的影响特点，分析了稳定回路对线性扰动和摩擦非线性扰动的抑制特性，并进行了仿真验证。结果表明：（1）弹体运动的加速度越大，弹体运动的摩擦耦合率越小。（2）摩擦力矩使系统频率特性测试结果出现误差，主要表现在幅值降低和相位超前，而且摩擦力矩越大误差越大，激励信号的幅值越小误差越大。在驱动器和电机不饱和的前提下，应采用较大幅值的激励信号。（3）稳定回路开环增益能直接反映其对线性扰动的抑制特征，但不能有效反映对弹体运动的摩擦耦合的抑制特征。提高开环增益和进行摩擦补偿是改善稳定回路隔离度的基本途径。5.针对扰动力矩补偿控制方法的工程应用问题，提出了质量不平衡力矩和摩擦力矩的测试方法；针对现有文献对双速度回路串级控制理论分析的局限性，采用描述函数法分析了双速度回路串级控制的有效性和适用性；研究了摩擦模型参数对补偿控制效果的影响，为基于摩擦模型的补偿控制的工程应用提供了理论依据；研究了基于摩擦模型的补偿和扰动观测器在导引头伺服机构中的综合应用方法，并对扰动观测器的结构进行了改进，所提出的摩擦模型+低通滤波器与扰动观测器相结合的补偿控制方法取得了较好的补偿效果。6.介绍了所研制的两轴两框架红外成像导引头伺服机构的机械结构、系统组成以及基于双DSP的伺服控制板的组成与基本工作原理；提出了系统各控制回路应该注意的问题以及解决方法；介绍了系统软件的基本设计思路，给出了伺服DSP定时中断程序的基本流程。提出了基于dSPACE的隔离度回路等效测试方法，给出了系统稳定回路的隔离度测试结果。更多还原

【Abstract】 Seeker servo mechanism is a key part of precise guiding weapons, the performanceof which directly affects the precision of the weapons. With the development of preciseguiding weapons, the dynamic performance of seeker servo mechanism is demandedhigher and higher. Characteristic indexes are corresponding standards of dynamicperformance of seeker servo mechanism, and how to get the reasonable characteristicindexes is the basis of the research work on seeker servo mechanism. Researching onthe main factors influencing performance of the mechanism and putting forward theeffective methods are the radical approaches to improve the performance of seekerservo mechanism. In this paper, the issue on designing characteristic indexes of imagingseekers is studied firstly. Then the coupled dynamics of seeker servo mechanism withtwo-axes gimbal are studied deeply, and the effect of mass imbalance torque andfriction torque on the control precision of seeker servo mechanism is also analyzed indetail. On the basis of the above works, several effective compensatation controlalgorithms are researched to improve the precision of the seeker servo mechanism fromthe aspect of the engineering application. The main works of this paper are as follows:1. On account of the carrier’s movement is the main factor to influence the imagingperformance of electric-optic (E-O) systems, it is important for the reasonable planningthe stabilization precision index of servo system to study on the influence mechanism ofcarrier’s movement. Firstly, the sources causing dithering of LOS by carrier’smovement are analyzed; then, with means of the geometric optics, the relationshipbetween the carrier’s moving and image’s moving on the focal plane is studied; finally,from the aspects of modulation transfer function, spatial resolution, and NIIRS, theinfluence of the carrier’s movement on imaging performance of E-O system is studied.From the point to satisfying the detecting capability of E-O system, the theoretic basisto confirm the stabilization precision index is put forward.2. As to the issue design the indexes of imaging seeker’s control system forsearching, tracking and stabilizing, the main working principle of the seeker isintroduced, and the integrant techniques of seeker servo system are put forward; therelationship between the searching blind regions with the searching velocity is studied.According to the influence of image moving on the performance of detector, the methodof conforming searching velocity is given. From the aspects of the maximal velocity ofLOS and the real time requirement of the image tracking algorithm, the limit of seeker’stracking velocity is presented. The main factors influencing tracking precision of thesystem are analyzed, and the method of conforming tracking precision indexes isdeduced. Taking account of the requirements of the actual system and the effect of thecarrier’ s movement on the performance of E-O system, a kind of design method of seeker’s stabilization precision index is put forward on the basis of the research work.3. On account of better researching on the influence of mass imbalanced torque oncontrol precision of the seeker servo mechanism, the kinematics model of seeker servomechanism are established; furthermore the dynamics model with mass imbalancedtorque are also constituted based on the theorem of angular momentum. The coupleddynamics among missile’s body, seeker servo mechanism are also researched, whichlead to the direction of structure’s design of seeker’s servo mechanism. Finally thesimulation experiments are taken to validate the established models, the results of whichshow the effect of the external disturbance torque on control precision of the seekerservo mechanism and provide foundations for subsequent research works such asstructure optimizing and disturbance compensatation and so on.4. In order to attenuating the effect of friction torque on the control precision of theseeker servo mechanism, the characteristics of friction torque on coupled movement andfrequency trait of the system are researched, as well as the effects of stabilizationcontrol loop on linear disturbance and nonlinear disturbance such as friction areanalyzed, and the simulation experiments are taken to validate the research work, theresults show:(1) The coupled friction torque ratio has the same change trend with thatof missile’s body acceleration.(2) Friction torque can cause error in systemidentification process, which exhibit decreasing amplitude and leading phase.(3) Theopen control gain of stabilization loop can manifests its attenuating performance onouter linear disturbance, but can’t exhibit the impaction on nonlinear disturbancecoupled with friction torque. Increasing the open control gain and compensating frictiontorque are the basic design rules for stabilization control loop.5. Before the research works of compensating the disturbance torque, a kind ofmethod to test mass imbalance torque and friction torque is presented in this paper. Inorder to eliminating the defects of the threory of the present control algorithm based ondouble velocity loop in series, the describing function method is used to analyzed thevalidity of the double velocity control method. The effect of friction model’s parameterson control precision of the system is studied, which is the foundation of compensatationcontrol algorithm based on friction model in practice. The cooperated use of frictionmodel and disturbance observer is studied deeply, and a kind of modified disturbanceobserver structure is put forward. The experimental results show that the presentedcontrol method with friction compensating model and low pass filter can achieve goodperformance, and can be realized easily in practice.6. The structure of the researched seeker servo mechanism is introduced as well asits constitution, working modes and the servo control circuit with double DSPs. Theissues to design different control loops are brought forward as well as the resolvingmethod. The basic ideas for software programming of the control system are given along with the working flow of DSP’s interrupt programs. Based on dSPACE，a kind ofmethod to testing disturbance attenuation is presented, and the test results of thesystem are also given.更多还原