【作者】 周擎坤；

【导师】 范大鹏；

【作者基本信息】 国防科学技术大学 ， 机械工程， 2011， 博士

【摘要】 本文围绕自动武器站系统的轻量化、小型化这一重要问题,以高精度、高动态性能、高缓冲效能的新型集成式柔顺缓冲机构为研究目标,针对柔顺直线导向与缓冲机构的设计问题进行深入研究,论文的主要研究工作如下:(1)自动武器站运动学模型和误差分析是论文的研究基础,分析了自动武器站系统工作原理、系统组成及其各部分的基本功用,运用齐次坐标变换原理,建立了光电搜跟单元与武器随动单元的运动学关系模型,分析了自动武器站指向误差成因机理,借助旋转矩阵理论建立了垂直度误差与武器站火力线指向精度的关系模型,提出了武器站机械结构的优化设计、制造与装配的精度要求,为柔顺缓冲机构设计奠定了基础。(2)针对缓冲系统参数优化目标的理论问题,分析了缓冲器在速度阶跃激励下的冲击响应和最大储能能力变化规律,提出了自动武器站摇架缓冲系统响应特性要求:最大后坐力、最大后坐位移和快速复位能力,推导出相应的加速度峰值、位移峰值、稳态振幅等特性的数学表达式,分析了不同约束条件下和不同阻尼比范围内的单自由度缓冲系统冲击响应的特性,建立了缓冲系统参数优化设计目标的数学模型,利用该模型获得了同时满足三个性能指标的最佳刚度、阻尼参数,为柔顺缓冲机构提供优化设计目标。(3)为解决柔顺直线导向与缓冲机构的构型设计问题,分析了各种柔顺梁单元的运动学特性,采用模块化方法构建了各种柔顺梁和柔顺直线导向机构的拓扑结构型式,提出了大位移柔顺缓冲机构的设计约束和设计原则,设计了具有导向功能和缓冲功能的改进型Roberts柔顺缓冲机构和多折叠柔顺梁缓冲机构,具有结构对称、工作行程大、导向精度高的特点,该方法为柔顺缓冲机构设计提供快速有效的设计手段,解决了柔顺机构设计过程中依赖于设计者的经验和灵感的问题。(4)针对导向刚度与缓冲刚度的理论计算问题,提出了对称简化方法,根据结构的对称性,利用半结构模型建立了柔顺直线导向与缓冲机构的导向刚度、缓冲刚度力学模型,分析了侧边直梁弹性变形和剪切内力对导向刚度、缓冲刚度的影响,建立了基于能量法的直梁、柔曲梁柔顺单元的力-位移特性分析方法,基于位移叠加原理推导了精确的导向刚度和缓冲刚度系数理论计算公式;选用性能优越的金属橡胶作为特定阻尼器,分析了金属橡胶的非线性缓冲刚度特性,建立了柔顺缓冲机构与金属橡胶阻尼的组合力学模型,为综合动力学特性与缓冲效能分析提供理论基础。(5)为了提高动力学建模与参数计算准确度,将柔顺梁分布质量的动能计入系统的总动能,采用瑞利能量法求解了柔顺悬臂梁单元、固定导向柔顺梁单元、圆弧柔顺梁单元、侧边直梁单元的集中质量参数计算公式。建立了以柔顺梁单元为主要特征的柔顺直线导向与缓冲机构的动力学模型,推导出一阶固有频率与各参量之间的关系式,通过有限元仿真分析验证了理论计算的准确性,并分析了各设计参数对于固有频率的影响,对优化结构参数、提高柔顺缓冲机构的固有频率、运动精度和改善性能具有重要意义。(6)建立了柔顺缓冲机构实验测试系统,进行了柔顺缓冲机构进行静态力学性能测试、模态实验和金属橡胶阻尼器非线性刚度测试与阻尼系数辨识,完成了柔顺缓冲机构与金属橡胶构成的组合型缓冲系统的仿真与实弹射击测试,对论文各章节提出的研究方法和结论进行了验证。更多还原

【Abstract】 Concerning the development of Automatic Weapons Station (AWS) with lightweight and miniaturization, this objective of this paper is to develop a integrated compliant buffer mechanisms with high dynamic performance, high precision, high efficiency and to research the design problem of compliant linear motion and buffer mechanisms, this thesis is composed of the following content:The kinematic model and working principle are the research base of this paper, the composition and structure function of AWS and its working principle are analyzed. Based on homogeneous transformation principle,the kinematic mode of opto-electrical acquisition, tracking system and weapon servo system is established .The pointing error of AWS including the cause of formation are analyzed, relational models between three squareness errors and pointing error of AWS are completed based on rotation matrix theory, and accuracy requirements are presented for the structure optimization design,manufacturing and assembly of the AWS,those are to provide a basement for the compliant buffer mechanism design.Based on the dynamic model of shock damper system, the transient response and maximum energy storage of several buffers under speed step excitation are analyzed. According to shock response limit, three performance indexes of shock damper system are presented: peak acceleration, peak displacement, steady state amplitude. The mathematical expressions of three performance indexes are developed and response characteristics in different damping ratio range are analyzed, the optimization mathematical model for shock damper system is built, the optimum stiffness, damper parameter suitable for three performance indexes at same time are obtained, those are to provide a optimization object for the compliant buffer mechanism.Based on the performance analysis of different compliant beam element, topological structure of compliant beam and compliant linear-motion are designed by using the modular method, making sure that the maximum guiding stroke and highest guiding precision are obtained in the specified area of compliant mechanism, design constraints and design principles of large stroke compliant buffer mechanism are analyzed , modified Roberts compliant buffer mechanism and multi-folded flexible beam compliant buffer mechanism are designed with guiding function and shock damper function, these mechanisms have advantages of the structure axially symmetric, large stroke , high linear motion precision. This method is to provide a design means to design the structure configuration of the compliant buffer mechanisms directly, quickly, and effectively, and to solve the problem of depending on the experience of designers in design processing of compliant mechanism.According to the structural symmetry, the theoretical model of guiding and buffering stiffness is completed by using the method of half model. The effect of elastic deformations of side beam and shear stresses on the guiding and buffering stiffness is analyzed. Force-displacement characteristic of straight compliant beam and arc compliant beam are analyzed also based on the energy method. Accurate theoretical calculation formulations of guiding and buffering stiffness are derived based on the principle of iterative displacement; it can be used for dynamical modeling and analysis. For the accuracy of dynamics modeling, kinetic energy of compliant beam mass is included in the system total kinetic energy. The calculation formulations for lumped mass parameter of cantilever beam, fixed-guided beam, arc compliant beam, side beam are derived based the method of Rayleigh energy. The multi-degree lumped parameter dynamical model of compliant linear-motion and buffer mechanism with the compliant straight beam are built, and the relationship between first order natural frequency and structure parameter are analyzed, it can be used for improving natural frequency, motion precision and performance.The composition of experiment setup is introduced, and force-displacement testing, modal testing, non-linear stiffness testing and damper identification of metal-rubber are completed. Shooting test for the composed shock damper system with compliant buffer mechanism and metal-rubber are accomplished, the accuracy and effective of research method and results are validated.更多还原