Aiming at the large nonlinear error of tool center point trajectory in the current five-axis Computer Numerical Control (CNC) machining by using G01 instruction for five-axis linear interpolation

a direct linear interpolation method based on the six parameters of five-axis machining tool position is proposed by taking A-C double pendulum head five-axis CNC machine tool as the object. Firstly

the method uses the principle of data sampling interpolation to interpolate the machining tool position to obtain the coordinates of the interpolation tool center point and the unit vector of the interpolation tool axis in the workpiece coordinate system

so that the interpolation tool center point falls on the ideal tool center point trajectory. Then

through the method of homogeneous coordinate transformation

the real-time post-processing of the interpolation tool position data is carried out to obtain five motion control coordinates in the machine tool coordinate system

so as to drive five feed servo axes to realize five-axis CNC machining.The simulation verification of the actual datavia MATLAB is carried out. The results show that the present method can ensure that the interpolation tool center points can fall on the ideal linear path segment to be interpolated

which effectively reduces the nonlinear error of the tool center point trajectory. It has good application for improving the control accuracy and processing quality of the tool center point trajectory of the five-axis CNC system.