This paper presents a short review for phase measuring deflectometry (PMD). PMD isa phase calculation based technique for three-dimensional (3D) measurement ofspecular surfaces. PMD can achieve nano-scale form measure...This paper presents a short review for phase measuring deflectometry (PMD). PMD isa phase calculation based technique for three-dimensional (3D) measurement ofspecular surfaces. PMD can achieve nano-scale form measurement accuracy with theadvantages of high dynamic range, non-contact, full field measurement which makesit a competitive method for specular surface measurement. With the development ofcomputer science, display and imaging technology, there has been an advancementin speed for PMD in recent years. This paper discusses PMD focusing on the difference onits system configuration. Measurement principles, progress, advantages and problems arediscussed for each category. The challenges and future development of PMD are alsodiscussed.展开更多
Usually,a multilens optical system is composed of multiple undetectable sublenses.Wavefront of a multilens optical system cannot be measured when classical transmitted phase measuring deflectometry[PMD] is used.In thi...Usually,a multilens optical system is composed of multiple undetectable sublenses.Wavefront of a multilens optical system cannot be measured when classical transmitted phase measuring deflectometry[PMD] is used.In this study,a wavefront measuring method for an optical system with multiple optics is presented based on PMD.A paraxial plane is used to represent the test multilens optical system.We introduce the calibration strategy and mathematical deduction of gradient equations.Systematic errors are suppressed with an N-rotation test.Simulations have been performed to demonstrate our method.The results showing the use of our method in multilens optical systems,such as the collimator and single-lens reflex camera lenses show that the measurement accuracy is comparable with those of interferometric tests.展开更多
Full-field three-dimensional(3D)measurement technology based on phase information has become an indispensable part of geometric dimension measurement in modern scientific research and engineering applications.This fie...Full-field three-dimensional(3D)measurement technology based on phase information has become an indispensable part of geometric dimension measurement in modern scientific research and engineering applications.This field has been developing and evolving for the study of highly reflective phenomena,diffuse reflections,and specular surfaces,and many novel methods have emerged to increase the speed of measurements,enhance data accuracy,and broaden the robustness of the system.Herein,we will discuss the latest research progress in full-field 3D shape measurement based on phase information systematically and comprehensively.First,the fundamentals of 3D shape measurement based on phase information are introduced,namely,phase-shifting and transform-based methods.Second,recent technological innovations are highlighted,including increases in measurement speed and automation and improvements in robustness in complex environments.In particular,the challenges faced by these technological advances in solving highly dynamic,composite surface measurement problems are presented,i.e.,with multiexposure techniques proposed for high dynamics that extend the dynamic range of the camera to reduce the effects of overexposure but increase the cost of time and have high hardware requirements,fringe adaptive techniques that overcome light variations but are computationally complex,and multipolarized camera techniques that reduce the effects of light variations but are sensitive to the light source.Third,the phase-shifting method combined with coding is proposed to improve the measurement speed,but the accuracy is slightly reduced.Deep learning techniques are proposed to cope with measurements in complex environments,but the dataset computation process is cumbersome.Finally,future research directions are suggested,and the challenges are presented.Overall,this work provides a reference for researchers and engineers.展开更多
Monolithic multi-freeform optical structures play significant roles in advanced optical systems by simplifying system structures and enhancing optoelectronic performance.However,manufacturing and measurement present s...Monolithic multi-freeform optical structures play significant roles in advanced optical systems by simplifying system structures and enhancing optoelectronic performance.However,manufacturing and measurement present significant challenges,which require the simultaneous assurance of form quality and relative positioning of multiple functional surfaces.Consequently,a deterministic form-position deflectometric measuring method is proposed based on Bayesian multisensor fusion,which effectively overcomes the inherent limitation of deflectometry in absolute positioning.Calibration priors were marginalised in the measurement model to improve fidelity,and a fully probabilistic measurement framework was proposed to eliminate numerical bias in conventional sequential optimisation approaches.Finally,a geometric-constraint-based registration method was developed to evaluate the form-position quality of freeform surfaces.The experimental results demonstrated the measurement accuracy could achieve a level of one hundred nanometres for surface forms and a few microns for surface positions.展开更多
基金funded by the Engineering and Physical Sciences Research Council(EPSRC)of the UK with the funding of the EPSRC Centre for Innovative Manufacturing in Advanced Metrology(Grand Ref:EP/I033424/1)the EPSRC Future Advanced Metrology Hub(EP/P006930/1).
文摘This paper presents a short review for phase measuring deflectometry (PMD). PMD isa phase calculation based technique for three-dimensional (3D) measurement ofspecular surfaces. PMD can achieve nano-scale form measurement accuracy with theadvantages of high dynamic range, non-contact, full field measurement which makesit a competitive method for specular surface measurement. With the development ofcomputer science, display and imaging technology, there has been an advancementin speed for PMD in recent years. This paper discusses PMD focusing on the difference onits system configuration. Measurement principles, progress, advantages and problems arediscussed for each category. The challenges and future development of PMD are alsodiscussed.
基金supported by the City Foundation of Nanchong(Nos.SXQHJH026 and 2021SXHZ041)。
文摘Usually,a multilens optical system is composed of multiple undetectable sublenses.Wavefront of a multilens optical system cannot be measured when classical transmitted phase measuring deflectometry[PMD] is used.In this study,a wavefront measuring method for an optical system with multiple optics is presented based on PMD.A paraxial plane is used to represent the test multilens optical system.We introduce the calibration strategy and mathematical deduction of gradient equations.Systematic errors are suppressed with an N-rotation test.Simulations have been performed to demonstrate our method.The results showing the use of our method in multilens optical systems,such as the collimator and single-lens reflex camera lenses show that the measurement accuracy is comparable with those of interferometric tests.
基金Foundation of China(U2341275,52075147)Scientific research project of Education Department of Hebei Province(JZX2024021).
文摘Full-field three-dimensional(3D)measurement technology based on phase information has become an indispensable part of geometric dimension measurement in modern scientific research and engineering applications.This field has been developing and evolving for the study of highly reflective phenomena,diffuse reflections,and specular surfaces,and many novel methods have emerged to increase the speed of measurements,enhance data accuracy,and broaden the robustness of the system.Herein,we will discuss the latest research progress in full-field 3D shape measurement based on phase information systematically and comprehensively.First,the fundamentals of 3D shape measurement based on phase information are introduced,namely,phase-shifting and transform-based methods.Second,recent technological innovations are highlighted,including increases in measurement speed and automation and improvements in robustness in complex environments.In particular,the challenges faced by these technological advances in solving highly dynamic,composite surface measurement problems are presented,i.e.,with multiexposure techniques proposed for high dynamics that extend the dynamic range of the camera to reduce the effects of overexposure but increase the cost of time and have high hardware requirements,fringe adaptive techniques that overcome light variations but are computationally complex,and multipolarized camera techniques that reduce the effects of light variations but are sensitive to the light source.Third,the phase-shifting method combined with coding is proposed to improve the measurement speed,but the accuracy is slightly reduced.Deep learning techniques are proposed to cope with measurements in complex environments,but the dataset computation process is cumbersome.Finally,future research directions are suggested,and the challenges are presented.Overall,this work provides a reference for researchers and engineers.
基金supported by the National Natural Science Foundation of China(52475551)the Natural Science Foundation of Shanghai(24ZR1406800)the Dreams Foundation of Jianghuai Advanced Technology Center(2023-ZM01C008).
文摘Monolithic multi-freeform optical structures play significant roles in advanced optical systems by simplifying system structures and enhancing optoelectronic performance.However,manufacturing and measurement present significant challenges,which require the simultaneous assurance of form quality and relative positioning of multiple functional surfaces.Consequently,a deterministic form-position deflectometric measuring method is proposed based on Bayesian multisensor fusion,which effectively overcomes the inherent limitation of deflectometry in absolute positioning.Calibration priors were marginalised in the measurement model to improve fidelity,and a fully probabilistic measurement framework was proposed to eliminate numerical bias in conventional sequential optimisation approaches.Finally,a geometric-constraint-based registration method was developed to evaluate the form-position quality of freeform surfaces.The experimental results demonstrated the measurement accuracy could achieve a level of one hundred nanometres for surface forms and a few microns for surface positions.
