Error compensation for machining of sculptured surface based on on-machine measurement and model reconstruction

With the wide application of sculptured surface in modern manufacturing industry, precision requirement of machining parts with sculptured surface has been increasing. After a part is processed and inspected, the measured data can be obtained. Yet, machining error reduction is still an important topic. This paper provides a novel methodology to compensate machining error of sculptured surface by using on-machine measurement (OMM) data to alter the position and orientation of theoretical CAD model. The approach does not need establishment of complex reconstruction model and modification of original tool path, so it is easy to be developed to engineering application. This method can be implemented in three steps. First, the representation of error evaluation for sculptured surface is given as the basis of error compensation. Second, the mirror method is applied to determine the optimal matching parameters of the theoretical surface. Then the reconstructed CAD model of the machined surface can be directly generated by modifying the position and orientation of theoretical surface so that the tool path is regenerated based on the reconstruction of the CAD model. Meanwhile, the influence of overcutting after compensation is considered. Eventually, experiments are performed on five-axis machine tools to prove its effectiveness. Results show that the method can effectively improve the machining accuracy of sculptured surface.