【作者】 董俊杰；

【导师】 李江雄；

【作者基本信息】 浙江大学 ， 机械工程（专业学位）， 2020， 硕士

【摘要】 在飞机装配过程中,通常采用沉头铆钉进行零部件之间的连接,沉头窝的深度精度直接影响连接质量,从而影响飞机疲劳寿命和气动外形准确度。本文基于浙江大学航空制造工程研究所自主研发的机器人螺旋铣孔系统,对锪窝深度控制技术进行研究。论文的主要研究内容及创新点如下:阐述了螺旋铣孔技术的研究现状,分析了螺旋铣孔的下游工艺锪窝中锪窝深度精度的重要性,介绍了国内外锪窝深度控制方法的研究现状,给出了论文的主要研究内容和框架。介绍了机器人螺旋铣孔末端执行器的结构组成以及自动化加工工艺流程,在此基础上,详细分析了制孔过程中压鼻结构、机器人变形、工件变形、刀具法向误差等对锪窝深度误差的影响。研究了锪窝深度误差控制方法,利用末端执行器中的长度计和直线光栅尺将加工过程中压脚位置的变化量实时补偿至刀具进给量,减少了机器人和工件变形引入的窝深误差;利用安装在压脚四周的多个激光位移传感器计算法向误差,并进行法向修正,减少了刀具法向误差引入的窝深误差。为了验证提出的窝深控制方案的有效性,基于机器人螺旋铣孔系统搭建了锪窝试验平台,并设计了三组不同目标锪窝深度的锪窝试验,试验结果显示:采用提出的锪窝深度控制方案后,窝深精度可以达到0.04mm,锪窝质量良好,满足实际生产需求。传统的法向修正方法存在一定局限性,导致某些特定情况下法向修正误差较大甚至法向修正过程无法正常完成。有鉴于此,设计了一种法向自适应修正的压脚结构,基于相关结构参数计算了法向修正的极限范围,并对该结构中的球面副进行了摩擦力学分析。最后,总结了全文工作,并对后续研究进行了展望。更多还原

【Abstract】 During the assembly process of an aircraft,the countersunk rivets are usually used to connect the aircraft parts.The depth accuracy of countersinks has a direct impact on the quality of the connection,and thus has effects on the fatigue life and the aerodynamic shape of the aircraft.This paper studies the control technology of the countersink depth based on a robotic orbital drilling system independently developed by the Institute of Aeronautical Manufacturing Engineering of Zhejiang University.The major work and innovative points of the thesis are as follows:The research status of the orbital drilling technology is expounded,and the importance of countersinking depth accuracy in the countersinking as a downstream process of the orbital drilling is analyzed.Then the research status of countersinking depth control methods at home and abroad is introduced.And the main research content and framework of the paper are demonstrated.The structure components of the orbital drilling end effector and the automatic machining process are introduced.Based on this,the effects of on the nose structure of pressure foot,the deformation of the robot,the deformation of the workpiece,and the normal deviation on the countersink depth error in drilling are analyzed.The control methods of countersink depth are researched.The length gauge and linear grating scale in the end effector are used to compensate the feed of the tool for the position change of the pressure foot in real time,which reduces the countersink depth errors introduced by the deformation of the robot and workpiece.The laser displacement sensor installed around the pressure foot is used for normal error calculation and the normal correction,which reduces the countersink errors introduced by the error of the tool axis and normal.In order to verify the effectiveness of the proposed countersink depth control scheme,a test platform based on the robotic orbital drilling system is set up,and three groups of countersinking tests with different target countersink depths are designed.The test results show that the accuracy of the countersink depth can reach 0.04 mm after applying the proposed countersink depth scheme,and the quality of the hole is good,which meets the needs of the actual production.The traditional normal correction method has some limitations which could cause large normal errors and aborted normal correction process in certain cases.Considering that,a normal-adapted pressure foot is designed.The limit range of the normal correction is calculated using its structure parameters,and the tribological analysis of the spherical pair in the structure is performed.Finally,the thesis is summarized,and the future research is outlined.更多还原