Investigation of Grinding Wheel Wear Using a White Chromatic Sensor

Abstract

This thesis involves the measuring of grinding wheel wear using an improved grinding wheel scanner. The positional resolution of the scanner has been improved from 26.5 μm to 0.65 μm with the addition of a second encoder. A vision based homing system was designed, and is able to track the position of the grinding wheel with a resolution of 2 μm. The implementation of a real-time controller improved the reliability of component synchronization and data acquisition. A slip compensation algorithm was written to correct the slip between grinding and friction wheels. The algorithm was proven to be able to compensate the slip to within the resolution of the sensor used. The positional repeatability of the scanner was measured to have average percent differences of 1.3% and 0.8% for the x and y directions, respectively. The homing system was measured to be repeatable within standard deviations of 27.6 μm and 19.3 μm for the x and y directions, respectively. The grinding wheel scanner measurements were then compared to SEM images and the surface areas of distinct features were measured to be within 11% of one another. The scanner was then used to study the wear of non-grooved and grooved grinding wheels. Analysis methods were developed to consistently extract parameters from the measured wheel surface. The extracted parameters were then used to calculate the G-ratios for the non-grooved and grooved wheels, which were found to be 6849 and 10215, respectively during steady state wear. A comparison of the power and forces to the uncut chip thickness was able to show the effect of the failure modes and clearly represented the size effect.