A new interpolation method was presented to satisfy the requirements of CNC machining for complicated curves. Firstly, the proposed method used cubic uniform B-spline segments based on a real-time overlapping combination algorithm to fit complicated curves, and then an adaptive algorithm was provided to calculate the interpolation step size through taking the chord error, velocity and acceleration into consideration, which can provide a good performance for improving the contour accuracy and reducing the impact on machine.At last, a trajectory planning strategy was put forward to guarantee the trajectory in the interpolation process meeting the smoothed constraints of velocity, acceleration and jerk. The simulation results of interpolation experiments show that the presented method can ensure high-speed and high-accuracy of machining complex curves, and has a good smooth feature of velocity, acceleration and jerk. This method feasibility has already been proved in real CNC system.

CNC machining, complex curve, cubic uniform B-spline, interpolation, trajectory planning

针对复杂曲线的数控加工，提出一种新的插补方法。首先采用一种三次B样条曲线的重叠拼接算法实时地对复杂曲线进行拟合，进而综合弓高误差、速度和加速度等因素，给出具有自适应调整能力的插补步长确定算法，该算法在提高轮廓加工精度的同时，可减小加工过程中的冲击。最后，对插补周期内节点的轨迹进行了规划，以确保运动轨迹满足速度、加速度以及加加速度的平滑约束条件。仿真实验结果表明，该方法在实时插补过程中，可以保证复杂曲线插补加工的高速与高精度，且具有很好的速度、加速度以及加加速度平滑性。

数控加工, 复杂曲线, 三次均匀B样条, 插补, 轨迹规划