冗余驱动并联机构的构型综合与伴随运动的消除

发布时间：2018-03-10 23:16

本文选题：冗余驱动并联机构　切入点：构型综合　出处：《北京交通大学》2013年博士论文　论文类型：学位论文

【摘要】：针对现代装备的高性能要求,本文提出利用冗余驱动并联机构来提升技术装备的整体驱动能力和提高机构的容错性能,并系统研究驱动冗余并联机构的构型综合理论。提出了一种系统综合冗余驱动并联机构的方法。选择单环机构或者多环机构作为机构的支链驱动单元,将机构可能的约束耦合在支链单元内完成,从而获得非过约束的或者低次过约束的冗余驱动并联机构。基于上述的构型方法,对具有三转动、三移动、两转动一移动、两移动一转动和四、五自由度运动的冗余驱动并联机构进行了构型综合,得到了系列构型。基于独立参数的设计需求,给出了冗余驱动并联机构的一般演化过程。不考虑机构末端动平台的自由度形式,空间刚体的位置和姿态可以由选定的与刚体固联的不共线三点决定。选定与动平台固联点的实现形式：空间点、平面点和直线点,通过单环或者多环机构实现固联点的运动,即可得到冗余驱动并联机构的系列构型。通过添加冗余驱动支链的方式,对机构可能出现的伴随运动进行了消除。针对典型的3-UPU并联机构总是存在非期望转动这一情况,进行了分析评估和规避研究。考虑约束误差对伴随转动的影响,约束螺旋与伴随转动之间的互易积将不再等于零,即：约束螺旋对伴随转动存在做功现象。基于此,得到了伴随转动自由度运动的范数表达,并以此作为衡量指标检验了误差约束对非期望转动的影响幅度。最后,提出了通过添加冗余驱动支链的方法,对机构可能出现的伴随运动进行消除。提出了一种新型4-UPU冗余驱动并联机构。该机构以2-UPU单环机构作为基础构型单元,消除了UPU类并联机构可能存在的伴随运动。此冗余驱动并联机构具有简单的正运动学求解,并且只有一种可以完全规避的结构奇异。当某一个驱动支链出现故障锁住时,机构动平台依然能够实现部分的空间移动运动,通过求解得到机构的容错工作空间。
[Abstract]:In order to meet the high performance requirements of modern equipment, this paper proposes to improve the overall driving capability of technical equipment and the fault-tolerant performance of the mechanism by using redundant drive parallel mechanism, and systematically studies the configuration synthesis theory of drive redundant parallel mechanism. In this paper, a method of synthesizing redundant parallel mechanism is proposed. The single ring mechanism or multi-ring mechanism is chosen as the branch chain driving unit of the mechanism, and the possible constraints of the mechanism are coupled in the branch chain unit. Thus, a redundant parallel mechanism with non-overconstrained or low-order overconstraints is obtained.; based on the above configuration method, a parallel mechanism with three rotations, three moves, two rotations and one movement, two moves and one rotation and four are obtained. The configuration synthesis of the redundant parallel mechanism with five degrees of freedom is carried out, and a series of configurations are obtained. Based on the design requirements of independent parameters, the general evolution process of redundant drive parallel mechanism is given. The position and attitude of the spatial rigid body can be determined by the non-collinear three points of the rigid body fixed to the rigid body. The realization form of the fixed point with the moving platform is selected: the space point, the plane point and the straight line point, and the motion of the fixed point is realized through the single ring or multi-ring mechanism. The series configuration of redundant drive parallel mechanism can be obtained. In this paper, the possible accompanying motion of the mechanism is eliminated by adding redundant driving branchlets. For the typical 3-UPU parallel mechanism, there is always an unexpected rotation. Analysis, evaluation and circumvention are carried out. Considering the effect of constraint error on the accompanying rotation, the reciprocal product between the constraint screw and the accompanying rotation will no longer be equal to zero, that is, the work of the constraint screw on the accompanying rotation will not be equal to zero. The norm expression of motion with rotational degrees of freedom is obtained, and the influence of error constraints on unexpected rotation is tested as a measure. Finally, the method of adding redundant driving branching chains is proposed. Eliminate the possible accompanying movement of the mechanism. A novel 4-UPU redundant drive parallel mechanism is proposed, in which the 2-UPU single loop mechanism is used as the basic configuration unit to eliminate the possible adjoint motion of the UPU parallel mechanism. The redundant drive parallel mechanism has simple forward kinematics solution. And there is only one structure singularity that can be avoided completely. When a fault lock-in of a driving branch chain occurs, the mechanism moving platform can still realize part of the spatial moving motion, and the fault-tolerant workspace of the mechanism can be obtained by solving the problem.
【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH112

【引证文献】