摘要
针对数控机床五轴联动轨迹误差影响加工精度的问题,文章提出了一种基于数控加工指令(G代码)计算轨迹误差的离线预测方法。首先分析了五轴联动线性插补的RTCP算法和数控系统的插补过程,基于G代码中所包含的数据得到程序段之间的位移当量、加工时间和实际速度等关键信息,结合RTCP算法与机床运动学正逆变换获得了任意插补周期的插补数据;然后,分别对平动轴与旋转轴建立包含三环控制环节、永磁同步电机、机械传动机构的伺服进给系统Simulink仿真模型,从而实现各轴实际位置的预测;之后采用三次样条插值法计算轮廓误差,通过构建连续轨迹模型提升误差估算精度。实际加工验证在五轴数控机床上完成,最终实验结果表明:该方法无需依赖机床硬件即可实现误差精准预测,各轴动态误差预测精度控制在±3μm以内,复杂加工轨迹轮廓误差预测精度达±2μm,验证了该方法的有效性。
To address the issue of trajectory errors affecting machining accuracy in five-axis CNC linkage systems,this paper proposes an offline prediction method for trajectory errors based on CNC machining in-structions(G-code).The approach first analyzes the RTCP algorithm for five-axis linear interpola-tion and the interpolation process of CNC systems.By extracting key information such as displace-ment equivalents,machining times,and actual speeds from G-code data,combined with RTCP algo-rithms and forward/inverse kinematic transformations of machine tools,interpolation data for ar-bitrary interpolation cycles are obtained.Subsequently,three-loop control structure models incor-porating permanent magnet synchronous motors and mechanical transmission mechanisms are es-tablished for both translational and rotational axes using Simulink,enabling the prediction of ac-tual axis positions.Cubic spline interpolation is then applied to calculate contour errors,construct-ing a continuous trajectory model to enhance estimation accuracy.Experimental validation was conducted on a five-axis CNC machine tool.Results demonstrate that the proposed method achieves precise error prediction without relying on machine tool hardware,with dynamic error prediction accuracy controlled within±3μm for individual axes and±2μm for complex trajectories,thereby validating its effectiveness.
作者
张云廷
陈光胜
Yunting Zhang;Guangsheng Chen(School of Mechanical Engineering,University of Shanghai for Science and Technology,Shanghai)
出处
《建模与仿真》
2025年第5期1039-1050,共12页
Modeling and Simulation
