In order to restrain the mid-spatial frequency error in magnetorheological finishing (MRF) process, a novel part-random path is designed based on the theory of maximum entropy method (MEM). Using KDMRF-1000F polishing...In order to restrain the mid-spatial frequency error in magnetorheological finishing (MRF) process, a novel part-random path is designed based on the theory of maximum entropy method (MEM). Using KDMRF-1000F polishing machine, one flat work piece (98 mm in diameter) is polished. The mid-spatial frequency error in the region using part-random path is much lower than that by using common raster path. After one MRF iteration (7.46 min), peak-to-valley (PV) is 0.062 wave (1 wave =632.8 nm), root-mean-square (RMS) is 0.010 wave and no obvious mid-spatial frequency error is found. The result shows that the part-random path is a novel path, which results in a high form accuracy and low mid-spatial frequency error in MRF process.展开更多
Computer-controlled sub-aperture polishing technology is crucial for achieving high-precision optical components.However,this convolution material removal method introduces a significant number of mid-spatial frequenc...Computer-controlled sub-aperture polishing technology is crucial for achieving high-precision optical components.However,this convolution material removal method introduces a significant number of mid-spatial frequency(MSF)errors,which adversely impact the performance of optical systems.To address this issue,we propose a novel controllable spiral magnetorheological finishing(CSMRF)method that disrupts the mechanism of conventional constant tool influence function(TIF)convolution material removal.In this study,we leverage the advantages of a time-varying spacing strategy and theoretically analyse how time-varying spacing,combined with the spiral swing process of the TIF,mitigates MSF ripple errors.The time-varying spacing method highlights the importance of controlling the characteristic frequency,while the CSMRF method demonstrates a smoothing effect on the errors within the MSF band.Our findings confirm that time-varying spacing and spiral swinging have complementary effects in managing MSF errors.Furthermore,by constraining the MSF error and specific frequency error,we identify the optimal combination of adaptive spacing and spiral angle using a genetic algorithm.On this basis,the MSF error is evaluated by combining the characteristic dwell time solution algorithm.Using the inertial confinement fusion optical element as an example,we observe a 99.938%reduction in the amplitude of the PSD curve of the mid-frequency ripple error with a spatial period of 1 mm,while the mid-frequency PSD curve remains within the standard line.Therefore,the proposed method can effectively control the specific MSF error distribution.This variable convolution kernel(TIF)sub-aperture polishing method provides a new idea for full-band cooperative error control.展开更多
基金Supported by the National Basic Research Program of Chinathe National Natural Science Foundation of China (Grant Nos. 61332, 50775215, 50875256)
文摘In order to restrain the mid-spatial frequency error in magnetorheological finishing (MRF) process, a novel part-random path is designed based on the theory of maximum entropy method (MEM). Using KDMRF-1000F polishing machine, one flat work piece (98 mm in diameter) is polished. The mid-spatial frequency error in the region using part-random path is much lower than that by using common raster path. After one MRF iteration (7.46 min), peak-to-valley (PV) is 0.062 wave (1 wave =632.8 nm), root-mean-square (RMS) is 0.010 wave and no obvious mid-spatial frequency error is found. The result shows that the part-random path is a novel path, which results in a high form accuracy and low mid-spatial frequency error in MRF process.
基金funded by the National Natural Science Foundation of China(62175259)Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA25020317)+3 种基金Science and Technology Innovation Program of Hunan Province(2022RC1138)Science and Technology Innovation Program of Hunan Province(2023JJ30079)Science and Technology Innovation Program of Hunan Province(2024JJ6460)Graduate Science and Technology Innovation Project of Hunan Prov.(CX20230019).
文摘Computer-controlled sub-aperture polishing technology is crucial for achieving high-precision optical components.However,this convolution material removal method introduces a significant number of mid-spatial frequency(MSF)errors,which adversely impact the performance of optical systems.To address this issue,we propose a novel controllable spiral magnetorheological finishing(CSMRF)method that disrupts the mechanism of conventional constant tool influence function(TIF)convolution material removal.In this study,we leverage the advantages of a time-varying spacing strategy and theoretically analyse how time-varying spacing,combined with the spiral swing process of the TIF,mitigates MSF ripple errors.The time-varying spacing method highlights the importance of controlling the characteristic frequency,while the CSMRF method demonstrates a smoothing effect on the errors within the MSF band.Our findings confirm that time-varying spacing and spiral swinging have complementary effects in managing MSF errors.Furthermore,by constraining the MSF error and specific frequency error,we identify the optimal combination of adaptive spacing and spiral angle using a genetic algorithm.On this basis,the MSF error is evaluated by combining the characteristic dwell time solution algorithm.Using the inertial confinement fusion optical element as an example,we observe a 99.938%reduction in the amplitude of the PSD curve of the mid-frequency ripple error with a spatial period of 1 mm,while the mid-frequency PSD curve remains within the standard line.Therefore,the proposed method can effectively control the specific MSF error distribution.This variable convolution kernel(TIF)sub-aperture polishing method provides a new idea for full-band cooperative error control.
