【作者】 杨志刚；

【导师】 林光春；

【作者基本信息】 四川大学 ， 机械设计及理论， 2006， 硕士

【摘要】 可调机构是随着机构学不断发展而产生的一类创新机构,是传统机构与现代应用技术相结合的产物,具有广阔的应用前景。与传统机构相比,可调机构的优点是具有一定的柔性,能有效地完成多任务,其灵活性介于传统机构和机器人之间。与机器人相比,可调机构具有可靠性高、精度好、易操作和维护、能耗少、成本低廉等优点。本文对可调机构相关理论进行了研究,涉及可调机构的综合、平面闭链机构和并联机构的动力学建模、基于虚拟样机进行新型并联机床的研究等。引入进化计算实现了多任务可调机构的优化综合,有效地解决了传统优化方法易陷入局部最优解的问题。为了提高算法的寻优性能,对进化计算进行改进,提出一种根据个体适应度自适应性调节变异率和变异量的方法。以平面四杆机构的刚体导引综合和平面六杆机构的函数综合为例阐述了这一方法。提出了基于构件子模型建立杆长和惯性参数可变的平面闭链机构动力学解析模型的方法,并基于子动力学模型构造了动力学并行算法。通过将机构拆解为单个构件,并分别建立针对单个构件的子动力学模型,计算其相应的驱动力/矩,然后叠加得到机构总的驱动力/矩。解析模型通过离线生成,并提出了各子模型矩阵元素实时代码的优化方法。该法有利于分析机构动力学特性并建立高效的动力学并行算法。由于动力学模型的离线建立和优化以及采用了并行计算,大大减少了在线计算时间,为机构的实时控制提供了有利条件。应用虚功原理和达朗伯原理建立了6-SPS并联机器人的动力学模型。通过更多还原

【Abstract】 The adjustable mechanisms is a kind of innovative mechanisms which comes forth with incessant development of mechanics. It is a product of combining traditional mechanisms with modern application technology, and has very vast potential applications. The advantages of adjustable mechanisms are that they have flexibility and can carry out multiple alternation tasks effectively as compared with traditional mechanisms. Their flexibility is between traditional mechanisms and robots. Compared with robots, adjustable mechanisms are more reliable, more accurate, easier to manipulate and maintain, and more economical. In this thesis, synthesis of adjustable mechanisms, dynamic models of planar close-chain mechanism and parallel mechanism, and a new type parallel machine tool based on virtual prototype are studied.The method of optimization synthesis of adjustable mechanisms for multiple alternation tasks based on evolutionary computation is presented, which can effectively solve the problem of easily running into local optimization solution by using traditional optimization method. In order to improve the optimization capability effectively, the algorithm of evolutionary computation is improved, and a method that can adaptively adjust mutation rate and mutation value according to fitness of individual is proposed. Take examples for rigid-body guidance synthesis of planar four-bar mechanism and function synthesis of planar six-bar mechanism to illustrate the method.Analytical dynamic model of planar close-chain mechanism, in which lengths and the inertia parameters of links can be changed, is established based on sub models of links, and a parallel algorithm is also proposed. The mechanism is disassembled to individual links and the dynamic sub models are established更多还原