This article proposed an angle measurement method based on second harmonic generation(SHG)using an artifcial neural network(ANN).The method comprises three sequential parts:SHG spectrum collection,data preprocessing,a...This article proposed an angle measurement method based on second harmonic generation(SHG)using an artifcial neural network(ANN).The method comprises three sequential parts:SHG spectrum collection,data preprocessing,and neural network training.First,the referenced angles and SHG spectrums are collected by the autocollimator and SHG-based angle sensor,respectively,for training.The mapping is learned by the trained ANN after completing the training process,which solves the inverse problem of obtaining the angle from the SHG spectrum.Then,the feasibility of the proposed method is verifed in multiple-peak Maker fringe and single-peak phase-matching areas,with an overall angle measurement range exceeding 20,000 arcseconds.The predicted angles by ANN are compared with the autocollimator to evaluate the measure-ment performance in all the angular ranges.Particularly,a sub-arcsecond level of accuracy and resolution is achieved in the phase-matching area.展开更多
This paper presents a compact XYZ micro-stage driven by an impact driving mechanism.A moving body is translationally actuated along the X-,Y-,and Z-axes in millimeter-scale range and with nanometer-scale resolution.Cr...This paper presents a compact XYZ micro-stage driven by an impact driving mechanism.A moving body is translationally actuated along the X-,Y-,and Z-axes in millimeter-scale range and with nanometer-scale resolution.Cr-N thin-film strain sensors are integrated into the micro-stage for closed-loop positioning.Closed-loop control is also carried out.The motion errors in six degrees of freedom are also investigated for this micro-stage.It is clarified by analysis of finite element method that rotational motion errors around the driving axis are caused by torques due to tensions from the elastic hinges of microstage.The mechanical structure of XYZ micro-stage to cancel out the torque generated is proposed and the second prototype is fabricated.Although the rotational motion error is successfully suppressed in the second prototype,a rotational motion error of more than 0.1°remains due to remaining torque and assembly error of the elastic hinges.Then,in order to reduce the rotational motion error,the prototype is designed in which the location of elastic hinges is single-layered.By designing a mechanical structure in which torque is suppressed,all rotational motion errors are successfully reduced to less than 0.05°in the prototype with single-layer hinges.展开更多
A new on-machine profiler employing a cantilever beam was proposed and developed to measure the sharp micro-cutting edges of precision cutting tools with low measuring force of 0.1 mN.The proposed profiler consists of...A new on-machine profiler employing a cantilever beam was proposed and developed to measure the sharp micro-cutting edges of precision cutting tools with low measuring force of 0.1 mN.The proposed profiler consists of a probe unit and a positioning unit.The probe unit employs a stylus mounted on the free end of a hollow triangular cantilever beam and a laser displacement sensor to detect the detlection of the cantilever beam.The positioning unit consists of two single-axis DC servo motor stages for precise positioning of the probe unit.The cantilever is designed with the assistance of the finite element method.In order to demonstrate the feasibility of the proposed measurement system,experiments are conducted and the measurement result for a micro-cutting edge is compared with that by a commercial profiler.Furthermore,a method to com-pensate for the measurement error caused by the lateral displacement of the cantilever beam is proposed.The compensated measurement results show good agreement within±2μm with those obtained by the commercial profler.展开更多
基金supported by the Japan Society for the Promo-tion of Science(20H00211).
文摘This article proposed an angle measurement method based on second harmonic generation(SHG)using an artifcial neural network(ANN).The method comprises three sequential parts:SHG spectrum collection,data preprocessing,and neural network training.First,the referenced angles and SHG spectrums are collected by the autocollimator and SHG-based angle sensor,respectively,for training.The mapping is learned by the trained ANN after completing the training process,which solves the inverse problem of obtaining the angle from the SHG spectrum.Then,the feasibility of the proposed method is verifed in multiple-peak Maker fringe and single-peak phase-matching areas,with an overall angle measurement range exceeding 20,000 arcseconds.The predicted angles by ANN are compared with the autocollimator to evaluate the measure-ment performance in all the angular ranges.Particularly,a sub-arcsecond level of accuracy and resolution is achieved in the phase-matching area.
基金supported by JSPS KAKENHI Grant Numbers JP 15H05759 and JP 20H00211。
文摘This paper presents a compact XYZ micro-stage driven by an impact driving mechanism.A moving body is translationally actuated along the X-,Y-,and Z-axes in millimeter-scale range and with nanometer-scale resolution.Cr-N thin-film strain sensors are integrated into the micro-stage for closed-loop positioning.Closed-loop control is also carried out.The motion errors in six degrees of freedom are also investigated for this micro-stage.It is clarified by analysis of finite element method that rotational motion errors around the driving axis are caused by torques due to tensions from the elastic hinges of microstage.The mechanical structure of XYZ micro-stage to cancel out the torque generated is proposed and the second prototype is fabricated.Although the rotational motion error is successfully suppressed in the second prototype,a rotational motion error of more than 0.1°remains due to remaining torque and assembly error of the elastic hinges.Then,in order to reduce the rotational motion error,the prototype is designed in which the location of elastic hinges is single-layered.By designing a mechanical structure in which torque is suppressed,all rotational motion errors are successfully reduced to less than 0.05°in the prototype with single-layer hinges.
基金This research was supported by the Japan Society for the Promotion of Sciences(JSPS)KAKENHI(15H05759,20H00211).
文摘A new on-machine profiler employing a cantilever beam was proposed and developed to measure the sharp micro-cutting edges of precision cutting tools with low measuring force of 0.1 mN.The proposed profiler consists of a probe unit and a positioning unit.The probe unit employs a stylus mounted on the free end of a hollow triangular cantilever beam and a laser displacement sensor to detect the detlection of the cantilever beam.The positioning unit consists of two single-axis DC servo motor stages for precise positioning of the probe unit.The cantilever is designed with the assistance of the finite element method.In order to demonstrate the feasibility of the proposed measurement system,experiments are conducted and the measurement result for a micro-cutting edge is compared with that by a commercial profiler.Furthermore,a method to com-pensate for the measurement error caused by the lateral displacement of the cantilever beam is proposed.The compensated measurement results show good agreement within±2μm with those obtained by the commercial profler.
