Development and Application of Interferometric On-Machine Surface Measurement for Ultraprecision Turning Process

Abstract

The continuing evolution of ultraprecision machining places an increasing need to perform surface measurement in the manufacturing environment. Development of on-machine surface measurement (OMSM) tools for ultraprecision machining processes will enable the reduction of measurement cycle time as well as the potential improvement of machining accuracy. In the present study, an in-house designed interferometer probe is integrated onto an ultraprecision diamond turning machine. System configuration, calibration scheme and various scanning strategies are first presented. The benefit of OMSM preserves the consistency between the machining and measurement coordinate system. Two applications of OMSM for ultraprecision turning process are further investigated. To further improve the surface accuracy, corrective machining is carried out based on the on-machine measured data. The profile accuracy of a cosine curve sample was improved after corrective machining with OMSM. Moreover, process investigation with OMSM was employed to model the effect of process parameters on the form error in ultraprecision cylindrical turning process. OMSM enables the consistent measurement of part coordinates for each experimental run, which is critical for acquiring a deterministic response for empirical modeling. A reduced quadratic model was built by means of response surface methodology and verified by the test for significance of the regression model. The confirmation tests show that the model predicted value conformed to the experimental value with a difference less than 4%.

A Comparison of the Probes with a Cantilever Beam and a Double-Sided Beam in the Tool Edge Profiler for On-Machine Measurement of a Precision Cutting Tool

“…For on-machine measurement, two kinds of methods are generally employed; noncontact methods and contact methods. Non-contact measurement based on the principle of interferometry, optical sensors, optical microscopy, or three-dimensional imagining technology can realize a fast evaluation without any damage to workpiece surfaces [10,[12][13][14][15][16][17]. Nevertheless, most of them have high requirements on the measuring environment, such as temperature, vibration, and humidity [18,19].…”

Development of surface reconstruction algorithms for optical interferometric measurement

“…13, an interferometric on-machine probing system is integrated into a three-axis DTM. A machine scanning error model has been established to calibrate this on-machine measurement system [228,229]. Even though on-machine measurement and compensation still face many difficulties in practical applications (e.g., the disturbance of cutting fluid and chips, the vibration of the machine tool, the accessibility of CNC controller, and the data acquisition speed), it is undoubtedly evolving as the key enabling technology to improve machining accuracy and surface quality, boosting the machining-metrology integration.…”

On-Machine Measurement of Profile and Concentricity for Ultra-Precision Grinding of Hemispherical Shells

“…If the off-machine measurement is chosen, secondary clamping errors are introduced. In comparison, on-machine measurement avoids this issue and significantly improves the machining efficiency [ 8 , 9 ]. In addition, the excellent positioning and motion accuracy of current ultra-precision machine tools on each axis extend the measuring range and ensure invariance of the measurement datam.…”