六自由度Stewart并联机构结构的优化设计

发布时间：2018-04-08 07:15

本文选题：Stewart并联机构　切入点：评价指标　出处：《哈尔滨工业大学》2011年硕士论文

【摘要】：Stewart并联机构是近年来机器人领域的又一热点研究方向,由于其结构形式的特殊性,并联机器人弥补了串连机器人刚度低、负载能力差、关节累积误差大等缺点,为机器人领域做了很好的补充。并联机构在近20年发展迅猛,已经成功的运用于运动模拟器、并联机床、工业生产线、高精度医疗设备等相关的领域中。虽然Stewart并联机构有许多优点,但它由六个支腿同时驱动运动平台的运动,支腿之间的耦合运动特性非常明显,这就给并联机构的运动学正解带来了非常大的困难,因此也就引起了容易产生奇异位形、灵活性差等一系列的缺点,在并联机构的设计中如何避免这些缺点使机构的性能达到最佳就成为一个艰巨的任务。本文从反解运算着手展开对Stewart并联机构基础理论的研究,推导了运动学方程,运用Newton-Euler法和Kane法建立了单刚体、多刚体动力学模型,并以实际的算例研究了支腿对整个质量矩阵的影响,之后提出了并联机构的性能优化指标,为优化的展开做好了理论铺垫。为了验证所推导方程的正确性,利用ADAMS软件建立了参数化的模型,然后进行单自由度方向上的运动仿真,将所得的仿真曲线与理论推导的计算结果进行对比,来研究理论建模的正确性。在优化之前,对并联机构的设计参数与机构性能之间的影响关系进行了研究,得出机构在不同方向运动时的特点,然后根据优化操作的步骤选取优化参数、确定目标函数及其约束条件、选取优化算法,最后得到了优化结果,并对优化结果展开分析。最后为了提高设计效率,将并联机构总体结构设计的运动学、动力学、工作空间、频率特性分析、驱动机构设计等部分进行综合,编写了一套通用6自由度Stewart并联机构的总体结构设计程序。
[Abstract]:Stewart parallel mechanism is a hot research direction in robot field in recent years, because of its special structure, parallel robot for robot series low stiffness, low load capacity, disadvantages of joint accumulated error and so on, do a good supplement to the field of robotics. Parallel mechanism rapid development in the past 20 years, the use of has been successful in motion simulator, parallel machine tool, industrial production line and related fields of high precision medical equipment.
Although the Stewart parallel mechanism has many advantages, but it is made up of six legs while driving motion of the motion platform, coupled motion between the legs is very obvious, this gives the kinematics of parallel mechanism is brought very great difficulty, so it is prone to cause singularities, poor flexibility and a series of the disadvantages, how to avoid these disadvantages make the best performance of the mechanism has become an arduous task in the design of parallel mechanism.
This paper from the inverse operation to start research on the basic theory of Stewart parallel mechanism, the kinematics equation is derived, a single rigid body by using Newton-Euler method and Kane method, multi rigid body dynamics model, and the real example of the influence of the leg to the mass matrix, then puts forward the optimization performance index of parallel mechanism well, the theoretical foundation for the optimization. In order to verify the validity of the equation, establish the parametric model using ADAMS software, and then the motion simulation of the single degree of freedom, the simulation curve and the theoretical derivation of the results of the comparison, to study the correctness of theoretical modeling.
Before optimization, influence between the design parameters and the mechanical performance of parallel mechanism were studied in relation to the mechanism in different direction characteristic, then according to the optimal operation of the step of choosing optimal parameters, determine the target function and constraint condition, optimization algorithm, finally obtains the optimization results, and the optimization results analysis.
Finally, in order to improve the design efficiency, we integrate the kinematics, dynamics, workspace, frequency characteristic analysis and drive mechanism design of the overall structure design of the parallel mechanism, and compile a set of general structure design program of a general 6 degree of freedom Stewart parallel mechanism.

【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH112;TP242

【引证文献】