Study on pre-travel anisotropic characteristic of touch trigger probe and its calibration method

Systematic error resulted from the pre-travel of the touch trigger probe is non-ignorable consititutent of inspection errors for On-Machine Measurennet (OMM). Based on analyzing the working procedure of probe, the mechanics condition of triggering mechanism under working situation is performed. Utilizing the results, a probe pre-travel mathematical model is established, which can describe the pre-travel and its anisotropic characteristic quantitatively. Then a numerical simulation of the mathematical model along the radial direction of the probe is implemented. Using a high resolution displacement sensor and high speed data acquisition instrument together with a specially designed detection circuitry, a novel pre-travel calibration method and device is set up. By means of the presented device, the pre-travel characteristics of the probe along the radial direction over 360° have been obtained. Finally a contrastive analysis between theoretical model and experimental results is carried out.