MECHANICS, DYNAMICS AND CONTROL OF MACHINING SYSTEMS

机械加工系统的力学、动力学和控制

• 批准号: RGPIN-2016-03702
• 负责人: Altintas, Yusuf
• 金额: $ 3.35万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=689315
• 关键词: MECHANICS; DYNAMICS; CONTROL; MACHINING; SYSTEMS

Machining is the most widely used operation in manufacturing mechanical parts. Costly aerospace parts are machined from solid blocks by removing 90% of the material. Prototyping costs of mass production lines in the automotive industry can reach a few million dollars in order to shorten the machining time while avoiding scrap rates. The physical trial and prototyping of Computer Numerical Control (CNC) machine tools for targeted machining applications are costly and time consuming. The industry needs productive machining strategies to stay competitive by predicting the physical performance of manufacturing steps ahead of costly physical trials. This research contributes to the mathematical modeling of multi-axis machining operations and their interaction with machine tool structures, kinematics, and control systems. The mathematical models will be used to predict the outcome of the machine design and manufacturing scenarios, which will enable the engineer to optimize manufacturing operations. ***The kinematics and control research will be based on a novel, 9 axis, high speed high precision CNC Micro Machine developed in our laboratory. The machine has three linear motor driven axes with a magnetically levitated rotary table placed on a translational table. The machine's kinematics will be modeled, and 5 degrees of freedom motion will be delivered accurately while controlling 9 drives simultaneously. The machine will be tested in 5 axis micro-milling of dies and molds, as well as in 3D printing of plastics. The kinematics knowledge will be applied in modeling 5-axis CNC mill-turn machines which are widely used in the industry. The research in machining dynamics will focus on the prediction of cutting forces, torque, power and vibrations to simulate and optimize mill-turning and thin walled part machining operations in a digital environment. The thin walled parts experience severe chatter vibrations during machining which leads to poor surface quality and tolerance violations, hence limiting the productivity. As the material is removed during the machining, the mass and stiffness of the parts change continuously. Numerical modeling of part dynamics at each material removal step requires the solution of an eigenvalue problem from large stiffness and mass matrixes of the structure. Therefore, it is time prohibitive for use in production. This research will investigate the analytical and rapid updating of the structural dynamic models of the parts at tool workpiece contact zones along the tool path. The proposed method will be applied in 5 axis ball end milling of jet engine blades and thread turning of oil-gas transportation pipes. ***The proposed research will enrich the current knowledge in machining to achieve complete, science and physics based digital machining technology.

机械加工是机械零件制造中应用最广泛的操作。昂贵的航空航天零件是通过去除 90% 的材料由实心块加工而成的。汽车行业大规模生产线的原型制作成本可能高达数百万美元，以缩短加工时间并避免废品率。针对目标加工应用的计算机数控 (CNC) 机床的物理试验和原型制作成本高昂且耗时。该行业需要高效的加工策略，通过在昂贵的物理试验之前预测制造步骤的物理性能来保持竞争力。这项研究有助于多轴加工操作的数学建模及其与机床结​​构、运动学和控制系统的相互作用。数学模型将用于预测机器设计和制造场景的结果，这将使工程师能够优化制造操作。 ***运动学和控制研究将基于我们实验室开发的新型9轴高速高精度数控微型机床。该机器具有三个线性电机驱动轴，磁悬浮转台放置在平移台上。将对机器的运动学进行建模，并在同时控制 9 个驱动器的同时准确地传递 5 个自由度运动。该机器将在模具的 5 轴微铣削以及塑料 3D 打印中进行测试。运动学知识将应用于对行业中广泛使用的 5 轴 CNC 铣车床进行建模。加工动力学研究将重点关注切削力、扭矩、功率和振动的预测，以在数字环境中模拟和优化车铣和薄壁零件加工操作。薄壁零件在加工过程中会经历严重的颤振，导致表面质量差和违反公差，从而限制了生产率。随着加工过程中材料被去除，零件的质量和刚度不断变化。每个材料去除步骤的零件动力学数值建模需要根据结构的大刚度和质量矩阵求解特征值问题。因此，现在是禁止在生产中使用的时候了。这项研究将研究沿刀具路径的刀具工件接触区域的零件结构动态模型的分析和快速更新。该方法将应用于喷气发动机叶片的五轴球头铣削和油气输送管道的螺纹车削。 ***所提出的研究将丰富当前的加工知识，以实现完整的、基于科学和物理的数字加工技术。