Linear Axial Error Signal Measurement and Processing Method of a Machine Tool for Accuracy Compensation Improvement

With the rapid development of electronics, sensors, wireless communication, networks, and software, machine tool (MT) technology has entered a period of intelligentization in industry. As a result, experiential knowledge relying on domain experts will gradually be substituted by intelligent technology. The accuracy of MTs can be upgraded by reducing the human experience effectively. However, when dynamic errors resulting from the motion of MTs induce abnormally large composite accuracy errors, the errors must be removed by shutting down the MT or handled by periodic preventive maintenance. These processes are time-consuming and costly, and shutdown inspections affect a factory's production cycle and productivity. In this study, an accelerometer was integrated with a gyroscope to create an inertial measurement unit used to measure the accuracy error in the dynamic behaviors of MTs. The measured vibration signals of the acceleration and angular acceleration were processed by the basic mathematical operations of filtering and integration, and the subsequent values were merged using the data fusion method to remove the information and errors resulting from repeated integrations or cumulative frequencies of blended data. Finally, the accuracy errors of the MT and angle value errors were obtained with high reliability in this study. In an experiment to validate the accuracy of the signal measurement and processing of the constructed inertial measurement unit module, a movable table of MTs was tested under compensation error baselines of 15 and 50 mu m. In the case of 10 mm travel, the positioning value was increased by 5.58 mu m under 15 mu m testing and reduced by 2.34 mu m under 50 mu m testing. According to the measurement and operation, the inertial measurement unit block conformed to the principle of the measuring tool unit being at least 0.2-0.5 times the compensation unit, and the validation results matched the target.