基于Clifford代数的复杂曲面机器人铣削轨迹误差补偿策略研究

Compared with multi-axis CNC machine tools, industrial robots provide a new solution to complex surface machining due to the advantages of low cost, good flexibility and large workspace, etc. However, the geometric error of the robotic serial structure and compliance error caused by external cutting load could result in large milling trajectory errors, which affect the machining accuracy of complex parts dramatically. Therefore, this project, aiming to robot machining problem for complex surface, carries out the research about the theory and key technology to compensation strategy of milling trajectory error. By constructing constraint conditions of the geometry-kinematics-dynamics, the robotic milling trajectory planning for curved surface and its optimization algorithm are analyzed in Clifford space; The unified model and transfer rule of milling trajectory error are studied using Motor and Lagrange equation; Combining with the trajectory optimization and error unified model, the graded compensation method of robotic milling trajectory error is established in Clifford space, thereby reveals the law of dynamic interaction between robot and curved part. On this basis, taking the marine propeller as the typical part, the accurate control of trajectory tracking is achieved and the machining accuracy of parts is improved. The research achievement would provide a critical theory and technology support to develop the CAD-CAM-ROBOT process chain of robot milling, and improve the process level of robot machining for curved parts.

相对于多轴数控机床，工业机器人因具有成本低、柔性好、操作空间大等优势而成为复杂曲面加工的一种新解决手段。然而，机器人串联式结构的几何误差和切削外载荷引起的柔性误差会导致铣削轨迹产生较大偏差，显著影响曲面零件的加工精度。为此，本项目针对复杂曲面的机器人加工问题，开展铣削轨迹误差补偿策略的理论与关键技术研究。通过建立几何-运动学-动力学约束条件，分析Clifford空间机器人曲面铣削轨迹规划模型及寻优算法；利用马达算子和Lagrange方程研究铣削轨迹误差统一模型和传递规律；结合轨迹优化和误差统一模型构建机器人在Clifford空间的铣削轨迹误差分级补偿方法，从而揭示机器人与曲面零件的动态交互规律。在此基础上，以船舰螺旋桨为典型零件实现铣削轨迹跟踪的精确控制和提高零件加工精度。研究成果将为建立机器人铣削的CAD-CAM-ROBOT工艺链提供关键理论与技术支撑，提升机器人曲面零件加工的工艺水平。

复杂曲面零件因具有独特的几何形状与使用性能而被广泛应用于船舶、航空、模具等领域的关键装备中，如舰船螺旋桨、航空发动机叶片、汽车覆盖件模具等。这些曲面零件的制造技术水平代表着我国高端装备制造业的核心竞争力。在《中国制造2025》国家战略的推动下，工业机器人具有成本低、效率高、柔性好、操作空间大等独特优势，可为复杂曲面零件的加工提供一种新的解决方案。.本项目重点针对工业机器人“刚度弱、定位精度低”等不足，提出了基于李代数理论的机器人动力学参数通用辨识方法，推导了基于李代数理论的串联机器人Jacobian及高阶导数的解析表达，提出了基于对偶四元数的双机器人加工坐标系标定方法，建立了基于李代数理论的机器人铣削误差统一模型与误差补偿方法。通过研制的机器人铣削加工仿真软件RobMach和开展的相应实验，对关键理论和方法的正确性和可行性进行了验证，从而提高了复杂曲面零件机器人铣削加工的精度。围绕项目研究内容，在机器人领域权威期刊上发表SCI/EI收录论文9篇，其中7篇为第一作者或通讯作者；申请发明专利5项（授权3项），实用新型2项（授权1项），软件著作权3项。相关研究成果为复杂曲面机器人铣削的CAD-CAM-ROBOT工艺链提供了理论与技术支撑，有效解决了工业机器人加工过程存在的不足，在大型复杂曲面零件制造、机器人本体制造等诸多智能制造领域，具有重要的科学意义和工程应用价值。