闭环双输入并联调姿隔振平台机构学理论研究

发布时间：2017-12-27 01:31

本文关键词：闭环双输入并联调姿隔振平台机构学理论研究　出处：《燕山大学》2016年博士论文　论文类型：学位论文

【摘要】：面向精密载体设备对稳定工作环境的需求,提出以闭环双输入冗余自由度并联机构作为调姿隔振平台的构想,利用机构的冗余自由度实现调姿与隔振的分离补偿,通过并联机构传动实现调姿与隔振同步混合输出;采用局部闭环机构作为分支输入单元以改善驱动性能。本文综合了一类适用于调姿隔振平台的新构型,并开展此类新机构的运动学和动力学基础理论研究,主要研究内容如下:分析不同驱动方式实现同一混合运动的驱动特性。基于平面闭环机构综合双输入及多输入驱动单元,构造不同约束形式含多输入单元的串联运动链;基于约束螺旋理论型综合的一般方法,面向调姿隔振应用进行闭环多输入冗余自由度并联机构构型综合;分析机构自由度的连续性以及输入选取的合理性。对含有子闭环的机构形式进行判定,并给出判别方法;提出了子广义坐标的概念,将闭环机构输出杆的运动表示成关于子广义坐标的广义旋量形式,基于旋量代数体系的刚体运动学理论,研究冗余自由度和非冗余自由度含子闭环的并联机构运动学建模方法,推导机构各构件对广义坐标的影响系数,解决了一类分支含子闭环的并联机构运动学建模问题,并将此类机构的建模过程统一到基于旋量代数的运动学建模理论之中。推导了单刚体在物体坐标系和空间坐标系下以6维旋量表示的的牛顿-欧拉公式。基于虚功率原理和单刚体牛顿-欧拉公式的旋量表达,并结合以子广义坐标和广义旋量表示的含子闭环并联机构运动学模型,建立此类并联机构在关节空间和操作空间的动力学一般公式。以6-(PRRR)US和5-UPS/(RPRRR)RS两种含子闭环的并联构型为数值算例,进行理论计算,通过仿真验证了理论模型的正确性。定义了多项闭环双输入冗余自由度机构评价指标;以3-(RRPRP)-(4S)并联机构为具体实例,分别进行针对机构单性能指标的单参数尺度综合和单目标多参数尺度综合;综合考虑机构各项性能指标,分别进行调姿输入、隔振输入和调姿隔振混合输入下的多目标尺度综合,获取各种输入情况机构尺寸参数的Pareto最优解集。根据调姿隔振平台混合运动特点,研究冗余自由度闭环双输入机构输入求解方法;以6-(PRRPR)US机构为例,基于局部闭环的运动规律设计逐次逼近法,解决了此类机构反解时闭环输入单元的局部正解问题。根据调姿隔振应用情况,制定输入分配策略;面向车载设备稳定以及卫星观测相机精确指向,基于双输入求解方法与分配策略开展虚拟样机联合仿真,初步验证闭环双输入冗余自由度并联机构作为调姿隔振平台的可行性,并检验了输入算法与分配策略的正确性。最后加工制造实物样机,并开展各种形式的运动实验,进一步验证样机调姿隔振混合运动输出能力以及理论求解方法。通过对闭环双输入冗余自由度并联调姿隔振平台的研究,明确了此类机构运动学和动力学本质特征;给出双输入协调匹配工作的具体方法,并证明其在调姿隔振应用上的可行性;同时研究过程中对机构分析的一些优化与仿真手段,可以作为分析同类机构的参考途径。
[Abstract]:For stable working environment the demand of precision carrier equipment, put forward the idea to double closed loop input redundant parallel mechanism for adjusting the vibration isolation platform, using the mechanism of redundant degrees of freedom posture alignment and isolation of the separation of compensation, through the parallel mechanism driving posture alignment and isolation hybrid synchronization output; the local loop mechanism as a branch of input unit to improve the driving performance. In this paper, a new configuration suitable for the platform of vibration control and vibration isolation is synthesized, and the basic theory research of kinematics and dynamics of such new mechanism is carried out. The main research contents are as follows: the driving characteristics of different driving modes to achieve the same hybrid motion are analyzed. The plane closed loop mechanism with two input and multi input drive unit based on the structure of different constraint forms containing multiple input serial kinematic chain unit; the general method of constraint screw theory based on type synthesis, for adjusting vibration application of closed-loop multi input redundant parallel mechanism configuration synthesis; analysis of the degrees of freedom and continuity the rationality of input selection. To form closed loop mechanism with sub judgment, and identify methods; put forward the concept of generalized coordinates, the closed loop output link motion into generalized spinor form on sub generalized coordinates, the rigid body kinematics theory of spinor algebra system based on the research of redundant and non redundant degrees of freedom including the son loop parallel mechanism kinematics modeling method of each component is impact of institutions on the generalized coordinate coefficient, solves the problem of parallel mechanism kinematics modeling of a branch containing sub loop, and the kinematic modeling theory of such institutions to unified modeling process based on spinor algebra. The Newton Euler formula is derived for the single rigid body in the object coordinate system and the space coordinate system, which is expressed in 6 dimensional rotation. Based on the virtual power principle and the expression of the rotation of the single rigid body Newton Euler formula, combined with the kinematic model of the sub closed loop parallel mechanism represented by the sub generalized coordinates and Guang Yixuan quantities, a general dynamic formula for such parallel mechanisms in the joint space and operation space is established. The theoretical calculation is carried out with two subclosed loops of 6- (PRRR) US and 5-UPS/ (RPRRR) RS as numerical examples, and the correctness of the theoretical model is verified by simulation. The evaluation indexes of closed-loop dual input redundancy mechanism definition; with 3- (RRPRP) - (4S) parallel mechanism as an example, respectively according to mechanism of single performance index of single parameter and multi parameter comprehensive scale single target scale synthesis; considering the mechanism of the performance index, respectively, adjusting input, integrated vibration vibration input and adjusting vibration multi target scale vibration mixed input, to obtain the Pareto optimal solution set size parameters of different kinds of input mechanism. According to the attitude control of hybrid vibration isolation platform motion characteristics, solution of redundant double closed loop input mechanism inputs; 6- (PRRPR) US mechanism as an example, the motion law of successive approximation method of local loop design based on solving local institutions such inverse closed-loop input unit positive solutions. According to the attitude control of vibration isolation applications, making the input allocation strategy for vehicle stability and equipment; satellite camera pointing to the double input, calculation and allocation strategy to carry out joint simulation based on virtual prototype, verify the closed-loop dual input redundant parallel mechanism for adjusting the feasibility of vibration isolation platform, and verified by the input and allocation algorithm. Finally, the physical prototype is manufactured, and various forms of motion experiments are carried out to further verify the output capability and the theoretical solution of the prototype's attitude adjustment, vibration isolation and hybrid motion. Through the research on the closed loop and double input redundancy adjusting parallel vibration isolation platform, clear of such kinematic and dynamic characteristics; specific methods of job matching are two input coordinate, and prove its feasibility in adjusting vibration vibration on the application; at the same time some research on Optimization and simulation means of analysis on the mechanism in the process of the approach can be used for the analysis of similar institutions.
【学位授予单位】：燕山大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TH112;TB535.1

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