【作者】 王蕊；

【导师】 熊晓燕；

【作者基本信息】 太原理工大学 ， 机械工程， 2024， 博士

【摘要】 太阳翼-星体对接装备是航天器总装过程中重要的地面机械支持设备,现有翼-星对接调姿装备存在工作范围小、移动性差等问题,不能满足卫星型号多样化发展趋势。为适应太阳翼装调的柔性化需求,本文提出了一种具有双运动模态的可移动重载可重构冗余并联调姿平台。应用这一调姿装备,可以提高航天器的装配质量和效率。本文的研究内容对于冗余驱动并联机构的设计、尺度优化、驱动力分配与实践应用具有重要的指导意义。本文以实现大范围负载能力和高精度运动控制为目标,系统地开展了双模态可重构机构构型设计、运动学分析及优化设计、冗余并联调姿机构的运动/力传递性能分析、动力学建模和驱动力分配,以及双模态并联调姿机构样机研制等研究工作。最后,通过仿真和实验验证了所提出理论的有效性以及所提出方法的可行性。主要内容如下:(1)双模态调姿平台的构型设计。为了使调姿装备能够满足不同尺寸卫星与太阳翼对接的要求,本文提出了一种由轮式宏动平台和可重构微调机构组成,具有双运动模态的可移动重载可重构冗余并联调姿平台。进行了6DOF微调分支构型综合,构建了综合承载性指标,设计了分散四分支六自由度并联微调机构。为了使微调机构在宏动阶段失去地面约束后仍具有确定的运动,在相邻分支间设置串联耦合子链以约束分支间的相对移动。提出了支链间耦合策略,建立了以机构解耦和运动分流为基础的对称耦合机构综合方法,利用基于螺旋理论的约束综合方法,验证了该方法的可行性。(2)调姿机构运动学分析及优化设计。为了提高并联机构的刚度并增加工作空间,结合冗余驱动,针对本文提出的并联调姿机构,进行了运动学建模与分析,并求解了其可达工作空间。基于工作空间体积,采用单因素法分析了并联机构各杆件参数对调姿范围的敏感性。为消除尺度的差异,将工作空间体积与机构体积两个表征性能的指标进行归一化处理。采用响应面法建立各参数的回归模型,获得机构最佳参数组合,为解决并联机构大负载和小体积之间的矛盾提出新的结构设计思路。(3)冗余调姿机构的运动/力传递性能分析。针对冗余驱动机构运动/力传递性能分析时输出传递指标无法直接求解的问题,提出一种“锁定-驱动”策略,即锁定驱动副以限制自由度数的方式,建立冗余驱动机构输出传递性能的求解方法,定义了以中位数为基础的机构传递指标,进而建立起冗余驱动并联机构的运动/力传递性能指标体系和评价方法,为冗余机器人的性能分析和构型优选提供了理论依据。基于所提出的运动/力传递指标绘制了尺度优化前后机构的性能图谱,验证了尺度优化的合理性。(4)冗余调姿机构的动力学分析及驱动力分配。为了合理分配冗余驱动力,采用Lagrange方法和虚功原理结合的动力学建模方法,并引入广义坐标选取原则和逆动力学求解步骤,获得了并联调姿机构的显式动力学方程,通过仿真验证了动力学模型的正确性。针对冗余的驱动方式,基于驱动力最小二范数法提出一种改进的驱动力加权最小二范数法进行驱动力分配,并通过仿真验证了上述驱动力协调分配方案的可行性。(5)双模态冗余调姿机构控制策略。宏动模态采用麦克纳姆轮组成全向移动系统执行,并对其进行了运动学建模与控制策略设计。针对宏-微模态转换时由于地面不平整引起的分支与地面接触“虚腿”问题,提出一种随机误差调平补偿策略,即构建与地面状态相适应的坐标系,对理想运动学模型进行修正,并通过仿真验证了该策略的可行性。针对微动模态冗余驱动并联机构的特点,设计了一种调姿机构并完成了其试验样机研制,基于试验样机对其控制策略进行了实验验证。更多还原

【Abstract】 The solar wing-satellite docking equipment is an important ground mechanical support equipment in the spacecraft assembly process.However,the current solar wing-satellite docking posture adjustment equipment has the problems of small working range,poor mobility,etc.,which can not satisfy the development trend of diversification of the satellite model.In order to adapt to the flexibilisation demand of solar wing-satellite assembly and adjustment,a movable,heavy-duty reconfigurable,redundant and parallel posture adjustment platform with dual motion models is proposed in this paper.The research is of great significance in guiding the design,scale optimisation,driving force distribution and practical application of dual-modal redundant drive parallel mechanism.In order to achieve high-precision motion control and accommodate large loads,the paper systematically carried out the research work on the configuration design of the dual motion modes reconfigurable mechanism,kinematic analysis and optimal design,motion/force transmission performance analysis of the redundant parallel posture adjustment mechanism,dynamics modelling and drive force distribution,and the development of a prototype of the dual-modal parallel posture adjustment mechanism.Finally,the validity of the proposed theory and the feasibility of the proposed method are verified by simulation and experiment.The main contents are as follows:(1)Conformational design of a dual motion modes posture adjustment platform.In order to enable the posture adjustment equipment to meet the requirements of different sizes of satellites docking with solar wings,a movable heavyload reconfigurable redundant posture adjustment platform(Rr PAP)with dual motion modes is proposed in this paper.The Rr PAP consists of a wheeled mobile platform and a reconfigurable parallel posture adjustment mechanism(PAM).The configuration synthesis of six-degree-of-freedom(6-DOF)micro-motion PAM limb is carried out,and the comprehensive load-bearing index is proposed.A decentralized four-limb 6-DOF parallel micro-motion PAM is designed.In the macro-motion stage,for the PAM to still have a defined motion after being released from ground constraints,a serial coupling sub-chain is designed between adjacent limbs to restrict relative movement between them.A type synthesis method for symmetrically coupled mechanisms based on mechanism decoupling and motion distribution is proposed.The feasibility of the proposed method is demonstrated through an example using the constraint synthesis method based on screw theory.(2)Kinematic analysis and optimization design of posture adjustment mechanism.In order to enhance the stiffness of the parallel mechanism and expand the workspace,kinematic modeling and analysis are conducted for the proposed parallel posture adjustment mechanism in this paper,along with incorporating redundant drive.The reachable workspace of the mechanism is determined.The sensitivity of each parameter of the parallel mechanism to the posture adjustment range is analyzed using a one-factor method based on the workspace volume.In order to eliminate differences in scale,the two performance indexes,namely workspace volume and mechanism volume,are normalized.A regression model for each parameter is established using the response surface method to obtain the optimal combination of parameter for the mechanism.A new structural design concept is introduced to address the trade-off between large load capacity and small volume in parallel mechanisms.(3)Analysis of motion/force transmissibility performance in redundant parallel mechanism.In addressing the challenge of directly solving output transmission indexes when analyzing the motion/force transmissibility performance of redundant drive mechanisms,a"lock-drive"strategy is proposed.This involves locking the drive pair to limit the degrees of freedom and establish a solution method for the output transmissibility performance of redundant drive mechanism.The approach defines median-based transmission indexes and a system of motion/force transmissibility performance indexes and evaluation methods for redundant drive parallel mechanisms is established,providing performance analysis and configuration optimization for redundant drive parallel mechanisms.Based on the proposed motion/force transmission indexes,performance maps are drawn before and after scale optimization,verifying the rationality of scale optimization.(4)Dynamic analysis and drive force distribution of redundant posture adjustment mechanism.In order to reasonably distribute the redundant drive force,the dynamics modelling method combining the Lagrange method and the principle of virtual work is adopted,and the principle of generalized coordinate selection and the inverse dynamics solution step are introduced to obtain the explicit dynamics equations of the posture adjustment mechanism,and the correctness of the dynamics model is verified by simulation.Aiming at the redundant drive mode,an improved drive force weighted least two-paradigm method is proposed based on the drive force least two-paradigm method for drive force distribution,and the feasibility of the coordinated distribution scheme is verified through simulation.(5)Control strategy of dual motion modes redundant posture adjustment mechanism.The macro-motion mode is executed by an omnidirectional moving system composed of Mecanum wheels,and kinematic modelling and control strategy design are carried out.Aiming at the problem of‘false leg’of the limb-ground contact caused by the uneven ground during the macro-micro-modal transition,a random error levelling compensation strategy is proposed,i.e.,a coordinate system suitable for the ground state is constructed,and the ideal kinematics model is corrected,and the feasibility of the strategy is verified by simulation.According to the characteristics of the micro-motion mode redundant drive parallel mechanism,a posture adjustment platform is designed and its test prototype development is completed.The control strategy is verified by experiment based on the physical prototype.更多还原