新型5轴混联加工单元的后置处理算法

5轴混联加工单元因其高刚性、快速响应及灵活调姿等优点，已被视为复杂铝合金结构件高效加工的一种替代方案。后置处理是改善此类装备加工能力的重要环节。以一种新型5轴混联加工单元为研究对象，提出一种可提高其加工件表面质量的后置处理算法。首先，基于B样条曲线构造一种双参数曲线插补算法，进行刀尖和刀轴轨迹的光顺处理，并采用参数同步化保证刀尖点与刀轴点的同步插补。其次，通过推导混联加工单元的速度映射模型，构造驱动轴的速度分配算法以确保刀尖进给速度的稳定性；接着，运用混联加工单元的位置逆解与速度分配策略，将其末端的进给速度、光顺处理后的刀尖插补点及刀轴插补点转换成驱动轴的位置与速度运动控制点集，实现混联加工单元刀具轨迹的后置处理；最后，基于前期开发的实验样机开展一组S形试件的切削实验，验证所提后置处理算法的有效性。

Post-processing Algorithm of a Novel Five-axis Hybrid Kinematic Machining Unit

Due to the merits of high stiffness, quick dynamic response and flexible posture adjustment, 5-axis hybrid machine units have been regarded as an alternative solution for high-efficiency machining of aluminum alloy structural components with complex geometries. Post-processing is of great importance to the improvement of machine capacity of hybrid machine units. A post-processing algorithm is proposed to improve the surface quality of the workpieces for a novel hybrid kinematic machining unit. Firstly, by adopting the B-spline curve, a double parameter curve interpolation algorithm is formulated to smooth the tool tip and tool axis trajectory. And then, the parameter synchronization is used to ensure the synchronous interpolation of tool tip and tool axis. Secondly, the velocity mapping model of the hybrid kinematic machining unit is formulated and a velocity allocation algorithm is proposed to ensure the stability of tool tip velocity. Thirdly, by using the inverse kinematics and the velocity allocation algorithm, the feedrate, the tool tips and the tool axis vectors are converted into a set of motion control points of the servo motors. Based on this, the post-processing of tool-path is realized for the hybrid kinematic machining unit. Finally, based on a laboratory prototype of the hybrid kinematic machining unit, a set of machining tests on S-shape workpiece is carried out to verify the effectiveness of the proposed post-processing algorithm.