Abstract
This paper presents an in-process measurement technique, which is capable of conducting position identification and dimension characterization of defects, for repair of micro defects by using a fast tool servo with a force sensor. A thrust force map is in-process produced to indicate the cutting status with respect to the positions of the machine slide and the machine spindle measured by linear encoder and rotary encoder, respectively. The position of the defect is detected by observing the thrust force map to determine the location of the abnormal variation in the monitored thrust force. Confirmation and characterization of the defects are conducted by employing the force-controlled tool to measure the sectional profile of the defective microstructures. The identified position and the characterized dimension are fed back to carry out repair which can be thus with exact tool setting position and accurate repair path. Experiments were carried out on a nikel cylindrical workpiece with a diameter of 55 mm fabricated by using a micro diamond tool. Defects, with dimension on the order of 1 μm among a cut microstructure array over the outer surface of the cylindrical workpiece, were in-process detected and repaired to confirm the feasibility of the proposed method.
