Improvement of residual error in hydrodynamic polishing by recursive error compensation strategy

This paper proposes a recursive compensation strategy for removing or generating an arbitrary profile during hydrodynamic polishing. Volume removal analysis suggests that, to remove an arbitrary error profile, the tool dwelling-time at the machining area can be designed to be a linear function of the error profile. The tool dwelling-time distribution is solved by the recursive method. This method may leave a residual error between the actual and desired profile because of the finite machining zone and the non-uniform machining rate distribution. The analysis indicates that the dominant factors in deciding residual error include the number of iterations, size of the machining zone, tool step size, and wavelength and amplitude of the error profile. The results indicate that a larger residual error occurs when the wavelengths of the error profile are smaller than the machining zone, and vice versa. By decreasing the tool step, the residual error is also reduced. Furthermore, error profile with small amplitude can be more easily eliminated. The residual error can also be significantly suppressed by the number of iterations, compared to that of the direct calculation of tool's dwelling-time. Experimental results confirm that the analysis is correct and an arbitrary profile can be accurately removed by this recursive polishing strategy.