刚柔耦合柔性机械臂含摩擦碰撞动力学研究

发布时间：2018-01-11 19:21

  本文关键词：刚柔耦合柔性机械臂含摩擦碰撞动力学研究　出处：《南京理工大学》2016年博士论文　论文类型：学位论文

  更多相关文章： 含摩擦碰撞 高次刚柔耦合 柔性机械臂 多点碰撞

【摘要】：本论文在高次刚柔耦合理论基础上,对柔性杆柔性铰机器人含摩擦碰撞全局动力学的建模与算法问题进行了研究。柔性机械臂的含摩擦碰撞问题是最具挑战性的问题之一,广泛存在于各个工程领域中,例如:机械臂、大型雷达天线、太阳能电池板、运输车辆、制造设备,以及仿生肌肉骨骼系统等等。尽管已经取得了一系列重大进展,但由于该问题涉及到耦合变形的高度非线性、高瞬态的接触变边界非光滑性、粘滞与滑移的物理非光滑性、以及数值求解等问题,实现复杂多体系统的大规模计算机模拟仿真仍然是时下一个非常复杂的任务,因此对柔性机械臂的含摩擦碰撞动力学问题的建模与分析研究在理论发展和工程应用上的具有重要的价值和意义。本文的研究内容以及成果主要有:建立了含有多杆和多铰的机械臂的高次刚柔耦合动力学模型。系统由n个柔性杆和n个柔性铰链接构成。采用4×4齐次变换矩阵描述系统的运动。柔性铰简化为含质量效应的线弹性扭转弹簧。柔性杆的变形考虑横向、纵向、扭转、以及横向变形引起的纵向缩短,即高阶几何非线性耦合项。采用递归策略得到可适用于计算机编程和实时仿真的高次刚柔耦合动力学方程。编写了通用的C++多体动力学软件。通过仿真算例,研究了刚柔耦合模型与传统零次耦合动力学模型各自的适用范围,对系统在重力场中、微重力场中的大范围运动与变形进行了仿真分析,对铰的柔性效应和刚度进行了分析研究。采用连续接触力法处理多体系统含摩擦碰撞问题。引入数学规划中熵正则化方法的思想,分别建立法向碰撞和切向摩擦的光滑化修正模型以及接触/分离、粘滞/滑移切换准则,将多体系统含摩擦碰撞的非光滑力学问题光滑化处理。引入碰撞力势能的概念,运用拉格朗日方程程式化地得到碰撞产生的广义力,从而得到系统碰撞阶段的动力学方程。编写了相应的C++碰撞多体系统动力学计算模块。通过刚/柔复合摆经典算例以及Canadarm2简化模型算例的数值仿真,研究了柔/刚性铰、零次/高次刚柔耦合模型、不同接触模型、摩擦系数、指数系数等对系统响应的影响,比较了三种摩擦模型的区别。将多体系统含摩擦碰撞的非光滑力学问题光滑化处理,缩短了已有非光滑力学理论与工程实际应用之间的距离,提高了大型复杂柔性多体系统全局动力学的计算效率。采用附加约束法处理多体系统含摩擦碰撞的非光滑力学问题。基于变拓扑系统的物理思路,根据不同的系统状态,将全局动力学方程分为分离、碰撞初始、粘滞接触、滑移接触等几个阶段描述。采用冲量/动量法求解碰撞初始的速度不协调问题。根据粘滞/滑动接触条件构造附加约束法动力学方程,并给出接触/分离、粘滞/滑移切换准则,通过Baumgarte约束稳定化方法保证约束方程不违约。通过数值仿真准确揭示了碰撞点的粘滞、正向微小滑动、逆向微小滑动以及它们之间的切换等多样性的接触现象。采用互补算法处理柔性多体系统含摩擦多点碰撞问题。引入关联矩阵和四个接触点集来描述多点碰撞对的接触/分离、粘滞/滑移状态。全局动力学方程分为分离、碰撞初始、粘滞碰撞、滑动碰撞四个状态。碰撞初始速度跳跃条件采用冲量/动量法实现运动的协调。在连续接触状态中,根据粘滞/滑动、正/逆向滑动等状态构造接触约束,采用互补条件统一描述动力接触条件,得到简洁、准确且易于编程实现的碰撞动力学求解方程。通过对柔性机械臂与两障碍物含摩擦碰撞的数值仿真,研究了碰撞点位置的切换、碰撞点的粘滞/滑动、粘滞/正向微小滑动、粘滞/逆向微小滑动等接触多样性。
[Abstract]:In this paper, the higher the rigid flexible coupling theory based on the modeling and algorithm of global dynamics with friction and collision of flexible link and flexible joint robot is studied. With the frictional collision problems of flexible manipulator is one of the most challenging problems exist widely in various engineering fields, such as mechanical arm, large radar antenna, solar panels, transport vehicles, manufacturing equipment, and bionic musculoskeletal system and so on. Although it has made a series of significant progress, but because the problem involves highly nonlinear coupling deformation, non smooth boundary and high transient contact, physical viscous and non smooth slip, and the numerical solution of such problems. The computer realization of large-scale complex multibody system simulation is nowadays a very complex task, so the problem of friction modeling with collision dynamics of flexible manipulator and Analysis on the theory development and engineering application has important value and significance. The research contents of this paper and the main results are: the higher the rigid flexible coupling dynamic model of manipulator with multi lever and multi hinge. The system consists of N flexible bar and N flexible hinge structure. Using 4 * 4 homogeneous the transformation matrix to describe the motion of the system. The flexible hinge is simplified as linear elastic mass effect torsion spring. Considering lateral deformation of flexible rod, longitudinal, torsional, longitudinal and transverse deformation caused by shortening, namely high order geometric nonlinear coupling. Using recursive strategy to obtain high-order rigid flexible coupling dynamic equations can be applied to computer programming and real-time simulation the multi body dynamics software. The general preparation of C++. Through numerical simulation, the research scope of the rigid flexible coupling model with the traditional zero coupling dynamic model of the system in gravity In the field, large range of motion in microgravity and deformation are simulated and analyzed, and the effect of flexible hinge stiffness were analyzed. With the continuous contact force method of multibody systems with frictional collision problems. Introducing method of entropy regularization in mathematical programming thought, established normal and tangential friction collision the smoothing correction model and contact / separation, the stick / slip switching rule, containing frictional collision of multi body system of nonsmooth mechanics problems of smooth processing. By introducing the concept of collision force potential, using the Lagrange equation to obtain stylized generalized force generated by the collision, so as to obtain the dynamic equations of the system. The preparation of the collision stage the corresponding C++ collision of multibody system dynamics calculation module. Through the rigid flexible compound pendulum classic example and Canadarm2 simplified numerical simulation model for example, study the flexible / rigid hinge, zero / high strength The coupling model, different contact model, friction coefficient, influence coefficient index on the system response, the difference between three friction models. The frictional impact of multi body system of nonsmooth mechanics problems of smooth processing, shorten the existing non smooth mechanics theory and practical application of the project to improve the computational efficiency of large distance. The complex flexible multi-body system dynamics. The global constraint method of multibody systems with friction and collision of nonsmooth mechanics problems. The physical idea of variable topology based system, according to the different states of the system, the global dynamic equation is divided into initial separation, collision, viscous contact, sliding contact problems using several stages such as described. The impulse momentum method to solve the collision / initial speed coordination. According to the viscous / sliding contact conditions of structural dynamics the additional constraint equation, and gives the contact / separation, stick / slip shear lag Change rule, through the Baumgarte constraint stabilization method to ensure the constraint of default. Through the numerical simulation accurately reveals the viscous collision point, small forward sliding contact phenomenon between reverse micro slip and their switching diversity. The complementary algorithm of flexible multibody systems with friction multi points into association matrix and collision problem. The four contact points set to describe the multi point collision of contact / separation, viscous / sliding state. Global dynamics equation is divided into initial separation, collision, viscous sliding collision, the collision of four collision state. The initial velocity jump jump coordination conditions using impulse / momentum method. Moving in continuous contact state, according to the viscosity forward / reverse / sliding, sliding state structural contact constraint, the complementary conditions describe the dynamic contact conditions are simple, accurate and easy to realize the dynamic mechanics of collision The numerical simulation of frictional impact between a flexible manipulator and two obstacles is carried out. The location of the impact points, the sticky / slip of the impact points, the viscous / forward small slip, the viscous / reverse micro slipping are studied.

【学位授予单位】：南京理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TP241
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本文编号：1410883