针对复杂曲面笔式加工时位于曲面上的空间曲线型刀具轨迹,给出一种直接插补算法.即对以投影方式形成的位于曲面上的空间曲线形式的刀轨,根据导动曲线和刀触点轨迹线之间的几何运动关系,通过泰勒展开近似得到刀触点轨迹线上插补点所对应的导动线的参数,再反求间接得到刀触点坐标,从而生成控制机床运动的指令.该方法的实现扩充了CNC系统的轨迹控制功能,提高了复杂曲面的加工效率.仿真结果表明算法可行而且有效.该算法也可以应用到整体曲面加工中. Aiming at the space curve type tool path located on the curved surface in complex surface pen machining, a direct interpolation algorithm is given, that is, the tool path in the form of the space curve formed on the curved surface formed by the projection mode, Contact the trajectory of the geometric movement between the Taylor approximation to get the knives contact point on the trajectory of the interpolation line corresponding to the parameters of the guide line, and then indirectly obtained the knife contact coordinates, resulting in control of machine tool movement This method extends the trajectory control function of CNC system and improves the processing efficiency of the complex surface.The simulation results show that the algorithm is feasible and effective.The algorithm can also be applied to the overall surface machining.