A Simplified Method for Estimation of Roundness in Vibration Cutting System

The vibration cutting has attracted attention as a precision machining method for the difficult to-cut materials, including titanium, nickel, ceramics and so on. However, there are some cutting conditions where the vibration cutting cannot keep the worked surface roughness at a constant value. Therefore, it is necessary to make the system which keeps watch on the state of workpiece and estimates its surface quality during the vibration cutting. In this paper, we propose a new simplified method for the estimation of the workpiece roundness in the vibration cutting system. Our method uses time-series data of the workpiece displacement measured by an eddy current sensor. We carry out experiments with varying the cutting speed, and show that the estimated roundnesses calculated by our method are in good agreement with measured ones when the vibration cutting system is in good cutting condition. Even if the chatter vibration arises in the system or the tool edge is worn, our method is able to give good estimated values.