【作者】 张斌；

【导师】 罗玉峰；

【作者基本信息】 南昌大学 ， 机械电子工程， 2012， 硕士

【摘要】 并联机构动力学响应是机器人动力学研究领域的一个重要方面,具有多变量、多参数耦合和形式复杂等特点,建模和求解效率直接影响机器人实时控制的灵敏度和精度。对此,本文基于序单开链法,结合虚功原理建立了平面和空间并联机构的动力学响应模型,该法将方程维数降至最低,具有形式简洁,求解效率高,通用性强,并与结构学、运动学分析高度统一的特点。具体内容包括以下几个方面：一、按照机构分解路线的耦合度K算法,将并联机械系统分解为约束度大于零、等于零和小于零三种类型的单开链单元。通过对约束度大于零单开链单元的运动学参数进行虚拟赋值,并利用约束度小于零的单开链单元建立运动学相容性方程完成整个系统的运动学分析。以此建立常用单开链单元的运动学模型,为后续并联机器人机构的动力学响应分析奠定基础。二、将序单开链法思想与虚功原理相结合,建立平面和空间并联机构动力学响应方程的一般通式,其中包含两种类型：1)不含运动副支反力动力学响应模型,通过速度和加速度分析,将各构件质心运动表达为关于广义速度和加速度的函数,并通过线性化处理与广义坐标特殊赋值的方法求得动力学响应方程系数矩阵中的各元素,避免对广义坐标进行复杂的偏导运算,从而提高建模效率；2)含运动副支反力动力学响应模型,通过解除单开链相关运动副约束和新增广义坐标的方法,并结合单开链的动态静力分析,得出系统在运行过程中各运动副的受力情况,能有效地降低动力学分析约束方程的个数,降低计算的复杂度。三、以一个平面3自由度(3-RRR)和空间4自由度(2SPS-2RPS)并联机器人研究为例,详细介绍了运用序单开链法进行动力学响应建模的一般思路和步骤。并通过Matlab编程计算得出它们的动力学响应特性曲线,以此对机构运动的动力学性能做出了简要评估。机构动力学分析是在结构学,运动学分析的基础上逐步建立起来的,序单开链法不仅使得动力学方程的维数降至最低,而且在运动学及动力学分析时都基于统一单开链单元模型,从而形成完整、统一的机构学理论。更多还原

【Abstract】 Parallel mechanism dynamic response is the important aspect in robot dynamics research field. it possesses the characteristics of more variables, more parameters coupled and complex formula form, whose modeling and solution efficiency directly influence the the sensitivity and accuracy of robot real-time control. To this, the plane and space dynamic responses model of parallel mechanism is established based on the Single Opened Chain(SOC) and the virtual work principle. the method deduces the dimension of dynamic response to the lowest.and has the peculiarity of form concision, solving efficiency, universality, What’s more, it is integrated with the structure analysis and kinematic analysis. The concrete content ran as follows:First, according to the structure decomposition algorithm κ, parallel mechanical system is decomposed to three types of single chain units, including constraint degree greater than zero,less than zero and equal to it. Endow the virtual value to the SOC whose constraint degree is greater than zero, and set up a chains of kinematic compatibility equations through the SOC whose constraint degree is less than zero.Then the kinematic analysis of whole mechanism system is done. In order to lay the foundation to the dynamic response analysis, the commonly used SOC unit kinematics model are accomplished.Second, the dynamic responses model of parallel mechanism based on the Single Opened Chain(SOC) and the virtual work principle contains two types:1) the model not containing kinematic pair reaction force. For this type, through the speed and acceleration analysis, the mass movement of every link is expressed about the function of general speed and acceleration. By means of linearization and special assignment to generalized coordinates, the elements of dynamic response equation coefficient matrix are got, Thus, a complex partial derivative operation to the generalized coordinates is avoided, so as to improve modeling efficiency;2) the model containing kinematic pair reaction force. To this, through releasing kinematic pair constraint on the SOCs whose constraint degree are less than zero,and increasing new generalized coordinates.combining with SOC dynamic static analysis, concludes out every kinematic pair reaction force in the process of system motion.This method can effectively decrease the number of dynamics analysis constraint equation, and reduce the complexity of the calculation.Third, take a planar3degrees of freedom (3-RRR) and space4degrees of freedom (2SPS-2RPS) parallel robot research as example, detailedly introduces the concrete process of ordered SOC method for the dynamic response modeling. Obtain the dynamic response curve of above two examples through the Matlab programming. In the end, reveal the mechanism motion dynamic performance and offer a brief evaluation for them.Dynamic response modeling is founded on structure analysis and kinematic analysis. Ordered SOC method not only make the dynamic equation dimension the lowest, but kinematics and dynamics analysis based on the same unit, Thus it can form a uniformed intagrated theory.更多还原