Optimal measurement angles of the three-probe spindle error motion separation technique

The three-probe error separation technique uses three displacement sensors to separate the spindle radial error motion from the artefact roundness error. The choice of appropriate sensor angles is crucial for an accurate and complete separation. This work discusses the optimal arrangement of the sensors' angular positions in detail, including the influence of angular position errors of the sensors on the separation results. The optimization goal is to find a suitable sensor arrangement to simultaneously maximize the minimum value and the average value of the transfer function, in order to improve the anti-interference ability and ensure measurement precision of the three-probe method without harmonic suppression. The result shows that there is a global optimum for the sensor angles for a specific range of harmonics. The obtained optimal measurement angles under different harmonic ranges should be useful for applications of the three-probe method.