自主移动钻铆机器人的基准检测与修正方法

自主移动钻铆机器人是一种适应机身筒段对接装配的8足并联机器人,由于其存在初始位置的不确定性以及加工制造等引起的理论与实际位置偏差,因此需要解决机器人制孔的基准检测问题。针对多坐标系系统和多种不同的基准形式,提出坐标变换方法与基准检测与修正方法,通过坐标系的空间变换,分别采用最小二乘法与间接转换法求解理论位置与实际位置的偏差,从而对待加工孔进行位置修正。实验表明,该方法能够实现机器人制孔的基准检测,完成偏差修正。     

轻型自主移动制孔机器人基准检测技术研究

针对大飞机机身大部件的装配需求,设计了一套柔性好、效率高、自动化程度高的轻型自主移动制孔机器人,并根据制孔机器人自身的结构特点,提出一套机器人视觉检测系统的手眼标定方案。在此基础上,提出了基于基准孔建立局部坐标系和空间坐标系转换的基准检测算法。实验表明:该技术能够实现机器人高精度制孔的精确定位,满足大飞机机身制孔位置精度要求。     

基于CATIA的五轴自动钻铆定位方法研究

自动定位是自动钻铆技术的核心,通过在CATIA平台上建立五轴自动钻铆机系统模型,并应用CATIA软件的二次开发技术,研究了基于五轴数控托架的自动钻铆定位方法,该方法是实现整个自动钻铆系统运动仿真和干涉检测的基础,同时也是实现五轴自动钻铆加工自动编程的基础。     

机器人自动钻铆系统的现场快速自定位方法

机器人自动钻铆系统在航空产品零部件制造和装配中得到了越来越广泛的应用。提出了一种利用钻铆机器人末端执行器上携带的单个工业相机进行现场机器人快速自定位的方法。该方法只需要以示教方式驱动钻铆机器人带动末端的工业相机对工件坐标系下6个以上坐标已知的定位点依次单独成像,即可简便快捷地确定出机器人基坐标系与工件坐标系之间的变换关系,结果表明,坐标系之间的旋转向量的偏差小于0.004,平移向量在x、y、z方向的偏差的绝对值都小于0.5 mm,实现机器人高精度自定位。推导了基于定位点依次单独成像的机器人自定位数学模型,并针对这一新模型提出了一种高效稳健的求解算法。该方法不受定位点分布结构的限制,可以直接利用自动钻铆系统自带的单个工业相机,无需激光跟踪仪等额外的坐标测量系统进行繁琐的三维测量和数据处理,因此机器人与工件的现场找正过程更加便捷高效。针对多个定位点依次单独成像所建立的定位模型和求解方法可以广泛应用于解决各类"手-眼"机器人系统的自定位问题。     

适应自动钻铆的壁板预装配柔性定位装置设计

飞机壁板在预装配完成后,自动钻铆时需利用托板对其重新定位,降低了装配效率。结合飞机壁板的结构特点和自动钻铆工艺等,设计了一套能够适应自动钻铆的壁板预装配柔性定位装置,并利用遗传算法对其结构进行了优化。该装置可实现对多块飞机机身壁板的柔性预装配,并可与自动钻铆机良好的结合,避免了飞机壁板在自动钻铆机托架上的二次定位,提高了装配效率。     

面向自动钻铆离线编程系统的运动仿真技术

针对五轴自动钻铆系统的结构和运动特点,构建了自动钻铆离线编程系统架构,开发了五轴自动钻铆系统加工运动仿真模块。根据调姿过程中钻铆点均相对固定于托架坐标系这一特点,提出了一种基于动坐标系位姿点的运动学反解算法;在此基础上提出了一种具有实时干涉检验功能的钻铆路径规划方法;在CATIA DMU模块通过CAA的二次开发方法实现机床运动仿真的需求;以某飞机壁板类零件对该仿真系统进行了验证。结果表明,所提方法能够有效识别出运动路径上的干涉部位并通过施加途经点的形式避让该干涉部位。     

大型飞机数字化测量技术的优化研究

飞机机身上关键特征的制造精度直接影响飞机产品的质量,因此,在产品交付之前应该对机身的各关键特征进行测量。针对目前测量方法存在的缺陷,在原方法的基础上提出一种优化的测量方法,即在建立飞机坐标系时,通过直线与平面相交的方式得到基准孔的实际圆心位置;同时根据机身关键特征的分布划分多个测量站位,分别在各个站位重新建立飞机坐标系测量对应的关键特征。进而提高测量的准确度,提高飞机的生产效率。     

基于数字化装配偏差建模的飞机舱段对接定位方案研究

机身成龙是飞机总装工艺中的一个重要环节,各舱段对接质量直接影响到机身整体外形精度,舱段对接工序中各舱段总成定位方案的选取对于机身外形协调精度具有重要的影响;开展面向飞机机身舱段对接装配的数字化装配偏差建模研究,针对飞机舱段大部件总装对接工艺,采用确定性定位方法对相邻部段对接面位置精度进行分析,建立不同基准定位方案的装配偏差分析模型和评价指数,对比不同定位方案对于装配质量的影响;在某实际机型中后机身与后机身舱段对接协调问题中得到应用验证。     

基于激光跟踪仪的机身桶段测量技术研究

目前传统测量技术已难以满足飞机制造中不断提高的检测要求,数字化测量技术已成为提高飞机产品检测效率与质量的重要手段。针对这一发展趋势,通过基于激光跟踪仪的机身桶段测量技术研究,系统地总结了飞机产品测量中激光跟踪仪测量场的组成、建立飞机测量坐标系的方法以及激光跟踪仪转站的原理。结合某型飞机前机身桶段的测量过程,重点介绍了利用激光跟踪仪对机身桶段关键特性和关键对接点进行在线测量及数据分析的方法,分析验证了激光跟踪仪系统在飞机产品测量中的应用情况。     

飞机壁板零件的装配与自动钻铆技术探析

飞机壁板零部件安装与配置期间容易变形,因此要求相关技术人员采用钻铆技术进行零部件装配工作。基于此,分析飞机壁板零件装配工艺及钻铆技术,探究飞机自动钻铆系统的建设与应用,以期为相关人员提供技术参考,确保飞机零部件装配工作的准确性与安全性。     

Kinematic modeling and parameter identification of a new circumferential drilling machine for aircraft assembly

Automated fastener hole drilling is a key technology for low-cost and high-quality assembly of aircrafts. In this paper, a new circumferential drilling machine for fuselage assembly of large aircrafts is introduced. In order to meet the required position accuracy of drilled holes, this paper focuses on the kinematic calibration of the machine in order to improve its positioning accuracy. A modeling strategy, which combines the Denavit-Hartenberg (D-H) method and a modified version of the Hayati-Mirmirani (H-M) method, is proposed to deal with the special kinematic structure of the arc-base drilling unit of the machine. Main issues in kinematic parameter identification such as definition of objective function, calibration data selection, acquisition of initial values, and setting of convergence criteria are also discussed. Experiments of repeatability testing and kinematic calibration have been performed, and the results show that the positioning accuracy of the arc-base drilling unit is comparable to its repeatability after calibration. This suggests that the proposed kinematic calibration method is effective. Actual drilling tests have been performed on a simulated aircraft fuselage after implementing the identified kinematic model in the machine’s control software. Position errors of drilled holes are within ±0.5 mm, which meets the requirement for fastener hole drilling in the fuselage assembly of large aircrafts.     

Research on surface normal measurement and adjustment in aircraft assembly

Drilling and riveting are commonly used in aircraft panel assembly process. Due to the fixture positioning error and the deformation of workpiece, the real position and orientation of the workpiece as well as its 3D geometry at the drilling position varies from the nominal CAD model, which would cause an unfavorable impact on assembly quality. Therefore, surface normal measurement and adjustment at the drilling position is of great importance. In this paper, a fast and effective non-contact measurement method for normal vector and height of moderately curved surfaces is accomplished by four laser displacement sensors, and a dedicated NC machine tool is also developed for normal adjustment. Firstly, a novel sensor calibration method based on laser tracker is introduced, which can acquire the sensors’ position and orientation in Tool Coordinate System (TCS) at the same time. The normal vector at hole position is calculated by cross product of any two non-parallel vectors constructed by the four laser projection points on the panel surface. Secondly, the kinematic model of the machine tool is established to calculate the adjustment of each axis of the machine tool with the Homogeneous Transformation Matrix (HTM). Besides, an innovative method to identify the distance of two rotary centers based on two laser interferometers is proposed. Finally, a series of experiments are conducted to validate the feasibility of the proposed method. The results show that the angle deviation can be reduced to less than 0.5° after adjustment, while the accuracy of the surface height is ±0.04 mm.     

飞机自动装配机器人设计及仿真

文中设计了一种用于飞机自动铆接装配的机器人,实现飞机钻铆自动化。为了满足铆接过程中对末端执行器位置及姿态的要求,设计中采用6自由度机械人加钻铆单元的总体结构,而钻铆单元由复合刀盘和分度机构两部分组成,其中复合刀盘上均匀布置4个钻孔单元和1个压铆单元,使同一刀盘能满足多种直径规格铆钉的铆接需要。     

附加外部轴的工业机器人自动钻铆系统分站式任务规划与控制技术

附加外部轴的工业机器人自动钻铆系统是飞机部件自动化装配的典型装备,传统的七轴联动工作模式对外部轴的制造精度和安装精度提出了很高的要求,导致实施成本高、周期长,故提出外部轴分站式工作模式。分析了机器人自动钻铆系统组成和工作流程,讨论了分站式工作模式下机器人任务规划的方法,研究了离散局部闭环伺服控制策略。试验平台测试结果表明,该方法将外部轴的重复定位精度从0.2mm提高到0.02mm。     

西门子SINUMERIK 840D在自动钻铆机数控托架集成系统研制中的应用

针对钻铆设备(RMS335),重新设计了其数控托架系统,由于托架各轴轴间跨距大,所以以西门子SINUMERIK840D数控系统作为开发平台,采用同步轴驱动方案,由840D中龙门轴功能实现各轴同步运动,设计了全闭环位置检测系统,实现了托架的自动定位,从而使定位精度达到设计要求。     

西门子SINUMERIK 840D在自动钻铆机数控托架集成系统研制中的应用

针对钻铆设备（RMS335）,重新设计了其数控托架系统,由于托架各轴轴间跨距大,所以以西门子SINUMERIK840D数控系统作为开发平台,采用同步轴驱动方案,由840D中龙门轴功能实现各轴同步运动,设计了全闭环位置检测系统,实现了托架的自动定位,从而使定位精度达到设计要求。     

A self-adaption normal direction and active variable stiffness low-frequency vibration-assisted system for curved surface drilling

The drilling operation occupies an important position in the aircraft assembly workload, and it accounts for a large proportion of the assembly cost. Previous reports show that drilling quality affects aircraft safety factor such as the probability of fatigue failure accidents. This paper proposes an automatic machining system for curved surface drilling. In this scheme, the self-adaption normal direction is realized by using the secondary positioning strategy (primary positioning and precise positioning). An elastic structure and the key positions smooth processing are applied to enhance the positioning guidance. The active variable stiffness mechanism satisfies the different requirements for system stiffness during the positioning stage and the drilling stage. Expansion sleeve locking and state switching of drilling assistance pneumatic cylinder lead to changes in the actuator's DOF and external forces, thereby achieving active control of the stiffness. Vibration-assisted machining technology is introduced to improve drilling quality. Compared with conventional drilling, the results show that this drilling system produces thin and slender chips, smaller burrs, and better internal surface quality.