Accuracy analysis and calibration of gantry hybrid machine tool

The kinematic accuracy is a key factor in the design of parallel or hybrid machine tools. This analysis improved the accuracy of a 4–00F (degree of freedom) gantry hybrid machine tool based on a 3-DOF planar parallel rranipulator by corrpensating for various positioning errors. The machine tool architecture was described with the inverse kinematic solution. The control pararreter error model was used to analyze the accuracy of the 3–00F planar parallel manipulator and to develop a kinematic calibration method. The experimental results prove that the calibration method reduces the cutter nose errors from ± 0.50 mm to ± 0.03 mm for a horizontal moverrent of 600 mm by compensating for errors in the slider home position, the guide way distance and the extensible strut home position. The calibration method will be useful for similar types of parallel kinematic machines.