Aero-engine nacelle acoustic liners are complex curved surface subassemblies with tens of thousands of dense acoustic holes for noise reduction. Traditional robotic drilling systems with a single spindle and conventional teaching programming cannot meet the high-quality and high-efficiency drilling requirements for nacelle acoustic liners. This paper developed a novel robotic multi-spindle drilling system, which integrates standard industrial robots with a multi-spindle drilling end-effector to drill acoustic holes on an acoustic liner. The task planning strategy and offline programming method are investigated for the robotic multi-spindle drilling of the acoustic liner. A dedicated offline programming software capable of quickly generating robotic machining programs has been designed and developed. A precise acoustic hole arrangement applicable to curved drilling zones is demonstrated. The virtual surrogate hole is introduced to target the array layout of the developed end-effector's multiple spindles. A virtual surrogate hole generation method is proposed based on the minimum mutually exclusive set cover and the greedy algorithm. After that, a virtual surrogate hole layout optimization method is developed using an adaptive genetic annealing algorithm. Then, the frame chain is constructed as the kinematic foundation in robotic multi-spindle drilling of a nacelle acoustic liner. The drilling pose planning of the multi-spindle end-effector based on normal vectors and coordinates of acoustic hole points covered by virtual surrogate holes is explored. And a multi-spindle drilling path planning algorithm is developed using the genetic algorithm. To drill the aero-engine nacelle of a large aircraft, an offline programming software for robotic multi-spindle drilling of the nacelle acoustic liner is developed by integrating the methods above. A case study of multi-spindle drilling task planning of a nacelle acoustic liner is carried out. The case study results indicate that, compared to traditional single-spindle robotic drilling systems, the developed multi-spindle drilling system increases drilling efficiency by approximately 347 %. Using the proposed multi-spindle drilling path optimization algorithm, the drilling path has been shortened by 84.8 %. These results validate the effectiveness of the proposed series of drilling task planning methods and the developed offline programming software, which significantly enhance drilling efficiency while meeting the technical requirements for drilling acoustic holes on the acoustic liner.

中文翻译：

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用于航空发动机短舱声学衬垫的机器人多轴钻孔系统的钻孔任务规划和离线编程


航空发动机短舱声学衬垫是复杂的曲面子组件，具有数以万计的密集声学孔，用于降低噪音。传统的单主轴机器人钻孔系统和传统的示教编程无法满足机舱声学衬垫的高质量和高效率钻孔要求。本文开发了一种新颖的机器人多轴钻孔系统，该系统将标准工业机器人与多轴钻孔末端执行器集成在一起，在声衬上钻孔。研究了声学衬垫机器人多轴钻孔的任务规划策略和离线编程方法。设计开发了一种能够快速生成机器人加工程序的专用离线编程软件。展示了适用于弯曲钻孔区域的精确声学孔布置。引入虚拟代理孔以针对开发的末端执行器的多个主轴的阵列布局。该文提出一种基于最小互斥集覆盖和贪婪算法的虚拟代理空穴生成方法。之后，使用自适应遗传退火算法开发了一种虚拟代理孔布局优化方法。然后，将框架链构建为机舱声学衬垫机器人多主轴钻孔的运动学基础。探讨了基于虚拟代理孔覆盖的声孔点法向量和坐标的多主轴末端执行器的钻孔姿态规划。并且使用遗传算法开发了多主轴钻孔路径规划算法。 为了钻探大型飞机的航空发动机短舱，通过集成上述方法，开发了一种用于机舱声学衬管机器人多轴钻孔的离线编程软件。对机舱声学衬垫的多轴钻孔任务规划进行了案例研究。案例研究结果表明，与传统的单主轴机器人钻孔系统相比，开发的多轴钻孔系统将钻孔效率提高了约 347%。使用所提出的多主轴钻孔路径优化算法，钻孔路径缩短了 84.8 %。这些结果验证了所提出的一系列钻井任务规划方法和开发的离线编程软件的有效性，在满足在声衬上钻声孔的技术要求的同时，显著提高了钻孔效率。