基于多视觉传感器融合的装配过程质量移动智能检测技术研究

针对航空航天领域大尺寸复杂产品装配过程质量检测过程中检测项目类型多、空间跨度大以及检测环境复杂等问题,提出一种基于多视觉传感器融合的装配过程质量移动智能检测框架。该框架以移动机器人为柔性运动载体,以多视觉传感器融合形成检测单元,可实现复杂产品装配过程质量的自动化、智能化检测。重点分析了基于模型驱动的视点与站位智能规划、基于情境感知的移动机器人自适应数据采集、多源数据融合与装配过程质量综合评定等关键技术,并通过实例验证了所提框架的合理性与有效性。

基于视觉的大尺度部件相对位姿实时测量方法研究

相对位姿是装配过程中的一项重要监控项。针对大尺度部件对接过程中的相对位姿测量需求,提出了一种基于视觉的相对位姿实时测量方法。该方法利用单目视觉技术,通过采集合作靶标的图像,实时解算大部段间的相对位姿,用于辅助大尺度部件的装配。首先,设计了一套相对位姿实时测量系统,包括搭载单目相机的视觉测量单元,以及用于辅助位姿解算的合作靶标;其次,对相对位姿测量的完整流程进行了研究,包含系统标定方法与实时位姿解算方法;最后,在实验室环境下对位姿测量系统的精度进行测试。试验结果表明,位姿测量系统在垂直于光轴方向的重复精度可达0.02mm,沿光轴方向重复精度优于0.2mm,输出位姿结果时间低于0.3s;对多测量单元组网测量进行了仿真计算,垂直于光轴方向的重复精度优于0.1mm,沿光轴方向重复精度优于0.2mm,输出位姿结果时间优于1.3s。试验结果表明,提出的方法可满足一般大尺度部件对接过程实时位姿监控与对接状态评估的需求。

基于多源测量数据融合的间隙与阶差自动化测量技术研究

针对间隙与阶差数字化测量问题,提出基于多源测量数据融合的间隙与阶差自动化测量技术,给出一种采用视觉测量传感器与全向机器人辅助执行机构协同配合的测量方式,并分析了系统组成。研究了该测量模式下的间隙与阶差测量工艺,并给出了多系统集成框架与控制方法以实现测量数据自动采集。最后基于QT开发间隙与阶差测量软件,并建立全向机器人测量平台进行试验验证。该研究为间隙与阶差高精度、自动化测量提供了技术支撑和方法指导。

面向大尺度产品对接的位姿测量模式研究与应用

位姿测量作为大尺度产品对接过程的关键环节,具有方法多样、理论复杂的特点。依据不同的测量原理划分位姿测量模式,并研究各类测量模式的特点,有助于从理论上分析位姿测量过程,对位姿精确测量具有重要的意义。首先,结合大尺度产品对接过程将部件的位姿划分为绝对位姿与相对位姿;其次,通过分析相对位姿的测量原理,开展位姿测量模式的研究,提炼出3种基本的位姿测量模式,并以此为基础衍生出3种复杂的位姿测量模式;最后,结合具体的相对位姿测量案例对位姿测量模式进行了应用研究,为大尺度产品对接任务中位姿测量方法的选择与优化提供了理论依据。

基于模型定义的测量规划与质量评定应用框架研究

对零件的三维测量规划技术进行研究,提出了基于多几何特性的测量规划与质量评定框架,并从基于MBD的测量需求表达、测量规划、测量执行与数据预处理、质量综合评定方法等方面进行了研究。最后基于CATIA二次开发平台进行原型系统开发,并进行了初步验证。该研究为基于模型的测量规划技术工程化与综合评定提供了技术支撑和方法指导。

基于有向点集的多面多孔式装配偏差分析与协调

多面多孔式装配是航天航空等大尺度部件装配/装调常见的连接形式之一,其空间装配关系复杂,调配环节多且存在耦合,以试错式的装配作业方式存在难度大、需反复试装与调配、装配质量一致性差、装配效率低等问题。采用"有向点"表征轴/孔配合的空间装配关系,提出了一种基于有向点集的多面多孔式装配协调数学模型,通过奇异值分解(SVD)分解法对基于有向点集的协调模型进行最优匹配运算,给出了装配调整量的计算方法。最后,以实际工程需求为应用背景,在实验室环境下进行了多面多孔式装配协调试验,结果表明基于测量数据的装配偏差分析与装配调整量计算方法可行。

Algorithm and experiments of six-dimensional force/torque dynamic measurements based on a Stewart platform

Stewart platform(SP) is a promising choice for large component alignment, and interactive force measurements are a novel and significant approach for high-precision assemblies. The designed position and orientation(P&O) adjusting platform, based on an SP for force/torquedriven(F/T-driven) alignment, can dynamically measure interactive forces. This paper presents an analytical algorithm of measuring six-dimensional F/T based on the screw theory for accurate determination of external forces during alignment. Dynamic gravity deviations were taken into consideration and a compensation model was developed. The P&O number was optimized as well.Given the specific appearance of repeated six-dimensional F/T measurements, an approximate cone shape was used for spatial precision analysis. The magnitudes and directions of measured F/Ts can be evaluated by a set of standards, in terms of accuracy and repeatability. Experiments were also performed using a known applied load, and the proposed analytical algorithm was able to accurately predict the F/T. A comparison between precision analysis experiments with or without assembly fixtures was performed. Experimental results show that the measurement accuracy varies under different P&O sets and higher loads lead to poorer accuracy of dynamic gravity compensation. In addition, the preferable operation range has been discussed for high-precision assemblies with smaller deviations.

Research on uncertainty in measurement assisted alignment in aircraft assembly

Operations in assembling and joining large size aircraft components are changed to novel digital and flexible ways by digital measurement assisted alignment.Positions and orientations（P＆O）of aligned components are critical characters which assure geometrical positions and relationships of those components.Therefore,evaluating the P＆O of a component is considered necessary and critical for ensuring accuracy in aircraft assembly.Uncertainty of position and orientation（U-P＆O）,as a part of the evaluating result of P＆O,needs to be given for ensuring the integrity and credibility of the result;furthermore,U-P＆O is necessary for error tracing and quality evaluating of measurement assisted aircraft assembly.However,current research mainly focuses on the process integration of measurement with assembly,and usually ignores the uncertainty of measured result and its influence on quality evaluation.This paper focuses on the expression,analysis,and application of U-P＆O in measurement assisted alignment.The geometrical and algebraical connotations of U-P＆O are presented.Then,an analytical algorithm for evaluating the multi-dimensional U-P＆O is given,and the effect factors and characteristics of U-P＆O are discussed.Finally,U-P＆O is used to evaluate alignment in aircraft assembly for quality evaluating and improving.Cases are introduced with the methodology.