5轴联动数控系统速度控制方法

高速加工过程中,在刀具路径上容易产生过冲,影响加工精度,因此必须提前对加工速度进行优化处理.基于数据采样法,利用当量位移和坐标轴方向系数实现了5轴联动线性插补;利用直线加减速原理进行插补前加减速控制;对速度前瞻控制方法进行了深入探讨,实现了相邻程序段转接处速度优化、连续微小程序段速度计算、减速点提前预测及前瞻程序段数动态选择等.仿真结果表明,速度平滑连续,有效地解决了5轴联动线性插补中的速度控制问题,提高了加工精度和加工效率.

Velocity control method of 5-axis simultaneous computerized numerical control system

In high-speed machining process, the overshoots often occur in the tool path and the machining accuracy is affected. To overcome this problem and optimize machining speed, based on the data sampling method, the 5-axis simultaneous linear interpolation was realized by using the equivalent displacement and the directional coefficient of the coordinate axis. The principles of linear acceleration/deceleration mode were applied in the pre-interpolation acceleration/deceleration control. The look-ahead method of velocity control was analyzed in detail, including the feedrate optimization of the fore-and-aft connective program blocks, the feedrate calculation of consecutive tiny program blocks, the forecast of the deceleration point and the dynamic selection of look-ahead program block amount. Simulation result showed that the velocity curve was smoother and more continuous. The velocity control of 5-axis simultaneous linear interpolation was solved effectively and the machining accuracy and productivity were greatly improved.