Theoretical Study of Path Adaptability Based on Surface Form Error Distribution in Fluid Jet Polishing

Abstract

In the technology of computer-controlled optical surfacing (CCOS), the convergence of surface form error has a close relationship with the distribution of surface form error, the calculation of dwell time, tool influence function (TIF) and path planning. The distribution of surface form error directly reflects the difference in bulk material removal depth across a to-be-polished surface in subsequent corrective polishing. In this paper, the effect of path spacing and bulk material removal depth on the residual error have been deeply investigated based on basic simulation experiments excluding the interference factors in the actual polishing process. With the relationship among the critical evaluation parameters of the residual error (root-mean-square (RMS) and peak-to-valley (PV)), the path spacing and bulk material removal depth are mathematically characterized by the proposed RMS and PV maps, respectively. Moreover, a variable pitch path self-planning strategy based on the distribution of surface form error is proposed to optimize the residual error distribution. In the proposed strategy, the influence of different bulk material removal depths caused by the distribution of surface form error on residual error is compensated by fine adjustment of the path spacing according to the obtained path spacing optimization models. The simulated experimental results demonstrate that the residual error optimization strategy proposed in this paper can significantly optimize the overall residual error distribution without compromising the convergence speed. The optimized residual error distribution obtained in sub-regions of the polished surface is more uniform than that without optimization and is almost unaffected by the distribution of parent surface form error.

Special Issue on “Micro/Nano Manufacturing”

“…The Special Issue contains 13 papers covering the topics listed above [6][7][8][9][10][11][12][13][14][15][16][17][18]. The treated micro fabrication technologies range from established processes like elliptical vibration cutting to novel process chains such as the formation of nanoparticle arrays by hot embossing and sputtering.…”

Time-dependent manufacturing processes lead to a new class of inverse problems

“…In atmospheric plasma etching, Dai et al ( 3 ) dealt with the nonlinear dependence of material removal rate on dwell time by considering a nested pulsed iterative method to evaluate and correct the time-varying nonlinearity of the process and enable the machining of pocket geometries in fused silica. In optical surfacing, Beaucamp and coworkers ( 4 ) showed how variable pitch path self-planning strategies, underpinned by a simple, linear model for material removal, can be used to improve the uniformity of a polished surface. In ion beam machining, an approximate solution of the inverse problem involves varying the dwell time of the beam on each pixel of the required surface ( 5 ).…”