广义并联机构低耦合可重构机理与模态空间解耦控制研究

发布时间：2018-08-14 20:15

【摘要】：与串联机构相比,并联机构的承载力高、运动精度高、机构刚度大、误差均化。在隔震、精密指向、运动模拟等诸多领域内并联机构都取得了广泛的应用。对并联机构的解耦研究至关重要。解耦研究可从结构解耦设计及控制策略研究两方面进行入手,本文研究机构构型由复合单叶双曲面描述的广义并联机构,对广义并联机构从解耦设计、结构优化、控制策略到实验验证等方面进行了研究。对广义并联机构构型分类、解耦定义及方法进行论述,基于解耦条件,给出广义并联机构复合解耦算法,该算法能求解广义并联机构沿Z轴平动及转动时构型调整方式,即下铰点调整轨迹,此时机构将保持解耦。据此提出机构可重构机理及全域低耦合思想,为设计全域低耦合广义并联机构提供依据。针对所提出全域低耦合广义并联机构进行结构优化设计,优化指标选择雅可比条件数,基于粒子群算法对全域低耦合广义并联机构进行了结构优化,所得到的机构构型在所限定的情况下条件数最小。进一步对广义并联机构进行全域耦合数值评价,论证可重构机理在设计全域低耦合广义并联机构的有效性。从控制策略上对广义并联机构的解耦控制进行研究。首先对广义并联机构进行模态分析,求解出其模态参数。通过仿真分析,探究机构构型、工作空间及模态控制对机构解耦的共同影响,分析模态控制改善机构解耦的程度。搭建了实验样机,在实验样机上进行了广义并联机构低耦合实验验证,实验分析广义并联机构在不同位置的时域和频域特性,以及比较重构和非重构情况对各自由度价交叉耦合的影响。通过实验验证了重构算法的有效性,证明了基于复合解耦算法的广义并联机构的全域低耦合性能。
[Abstract]:Compared with the series mechanism, the parallel mechanism has the advantages of high bearing capacity, high kinematic precision, large stiffness and homogenization of error. Parallel mechanisms have been widely used in isolation, precision pointing, motion simulation and many other fields. It is very important to study the decoupling of parallel mechanism. The study of decoupling can be carried out from two aspects of structural decoupling design and control strategy. In this paper, the configuration of the generalized parallel mechanism described by the compound single leaf hyperboloid is studied, and the decoupling design and structure optimization of the generalized parallel mechanism are presented. The control strategy and experimental verification are studied. The configuration classification, decoupling definition and method of the generalized parallel mechanism are discussed. Based on the decoupling condition, the compound decoupling algorithm of the generalized parallel mechanism is presented. The algorithm can solve the configuration adjustment method of the generalized parallel mechanism when it moves and rotates along the Z axis. That is, the lower hinge adjustment trajectory, this time the mechanism will remain decoupled. Based on this, the reconfigurable mechanism of the mechanism and the idea of global low coupling are proposed, which provides the basis for the design of the universal low coupling generalized parallel mechanism. Based on particle swarm optimization (PSO), this paper optimizes the structure of the global low-coupling generalized parallel mechanism by selecting Jacobian condition number as the optimization index, aiming at the structure optimization design of the proposed global low-coupling generalized parallel mechanism. The obtained mechanism configuration is the smallest in the defined conditions. Furthermore, the global coupling numerical evaluation of the generalized parallel mechanism is carried out to demonstrate the effectiveness of the reconfigurable mechanism in the design of the universal low coupling generalized parallel mechanism. The decoupling control of generalized parallel mechanism is studied in terms of control strategy. First, the modal analysis of the generalized parallel mechanism is carried out, and the modal parameters are solved. Through the simulation analysis, the influence of mechanism configuration, workspace and modal control on mechanism decoupling is explored, and the degree of improving mechanism decoupling by modal control is analyzed. The experiment prototype is built, and the low coupling experiment of the generalized parallel mechanism is carried out on the experimental prototype. The characteristics of the generalized parallel mechanism in time domain and frequency domain are analyzed experimentally. The effects of reconfiguration and non-reconfiguration on the valence cross-coupling of each degree of freedom are compared. The validity of the reconstruction algorithm is verified by experiments, and the global low coupling performance of the generalized parallel mechanism based on compound decoupling algorithm is proved.
【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】：2017
【分类号】：TH112

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