Autonomous navigation is a key technology for unmanned motion platforms to perform their tasks smoothly.The current approaches for daytime polarization navigation have been extensively researched.However,the polarizat...Autonomous navigation is a key technology for unmanned motion platforms to perform their tasks smoothly.The current approaches for daytime polarization navigation have been extensively researched.However,the polarization light intensity is the fundamental information within the polarization image,and the light intensity at night is 6-8 orders of magnitude lower than that during the day,which increase the noise and the loss of local polarization information due to occlusion,resulting in a significant decrease in the polarization orientation accuracy.Aimed at the problem,a bio-inspired model is introduced to denoise and enhance weak nighttime polarization patterns.Further,to address the issue of outlier interference in the occluded environment during practical application,a fast-fitting method of the solar meridian based on the anti-symmetric distribution of the polarization angle adjusted by Proportional and Differential(PD)control is proposed.The experimental results show that the method proposed in this paper achieves a dynamic orientation error Root Mean Square Error(RMSE)of 0.7°in the weak polarization mode at night and in the presence of local occlusion.The proposed method has strong robustness under weak polarization occlusion at night,and the orientation accuracy is improved by 97%and 80%in comparison to the least squares method,which provides a new method for polarization navigation at night.This effectively improves the robustness and environmental applicability of the bionic polarization compass for nighttime applications.展开更多
Achieving rational control over polarization states and color of circularly polarized luminescence(CPL)through simple modulation poses a challenging yet highly practical problem.To address this issue,we developed a me...Achieving rational control over polarization states and color of circularly polarized luminescence(CPL)through simple modulation poses a challenging yet highly practical problem.To address this issue,we developed a mechano-responsive chiral supramolecular system based on a cyclohexanediamide-derived gelator CCPy.This molecule exhibited a strong blue fluorescence accompanied by a distinct CPL signal upon forming a supramolecular gel in toluene.However,upon the application of mechanical force,the gel rapidly transformed into a faintly emissive suspension with a silent CPL signal,along with a notable morphological alteration.Furthermore,by implementing the circularly polarized Förster resonance energy transfer(CP-FRET)strategy,the mechano-responsiveness was effectively imparted to binary systems through the incorporation of dyes Nile red(NR)and coumarin 7(C7),thus realizing mechanical force-switchable green and red CPL systems.It was particularly noteworthy that by adjusting the ratio of CCPy,C7 and NR,a ternary mechanical force-induced CPL ON-OFF switch that emitted a standard white emission was achieved through sequential CP-FRET.Following this,an information encryption experiment was performed.This work provided a paradigm for fabricating smart multi-color and white-light CPL materials.展开更多
基于Microfacet理论,当光线照射到粗糙表面时会发生显著的多次镜面反射现象,而传统偏振双向反射分布函数(Polarized Bidirectional Reflectance Distribution Function,pBRDF)未能很好地描述这种现象,为了得到更精确的pBRDF模型,更好地...基于Microfacet理论,当光线照射到粗糙表面时会发生显著的多次镜面反射现象,而传统偏振双向反射分布函数(Polarized Bidirectional Reflectance Distribution Function,pBRDF)未能很好地描述这种现象,为了得到更精确的pBRDF模型,更好地分析材料的偏振特性,本文在包含镜面反射、漫反射和定向漫反射的三分量pBRDF模型基础上,进一步定义了高阶微相位角与一阶相位角的关系。改进后的pBRDF模型不仅考虑了多次镜面反射的几何衰减因子,还引入了微相位角的定义,从而建立了一个更全面的高阶镜面反射pBRDF模型。通过比较不同的pBRDF模型,并结合偏振特性采集装置进行验证,实验结果表明,本文提出的模型优于其他模型,三阶模型效果普遍优于二阶。在偏振图像渲染中,峰值信噪比和结构相似性平均分别提升10.09%和2.97%,呈现更加真实的渲染效果。验证本文提出的高阶镜面反射pBRDF模型能够更准确地描述目标表面的偏振特性。展开更多
基金co-supported by the Excellent Youth Foundation of Shanxi Province,China(No.202103021222011)the Key Research and Development project of Shanxi Province of China(No.202202020101002)+3 种基金the Fundamental Research Program of Shanxi Province of China(No.202303021211150)the Aviation Science Foundation of China(No.2022Z0220U0002)the Graduate Education Innovation Plan Project of Shanxi Province,China(No.2023KY588)the Shanxi Province Key Laboratory of Quantum Sensing and Precision Measurement,China(No.201905D121001).
文摘Autonomous navigation is a key technology for unmanned motion platforms to perform their tasks smoothly.The current approaches for daytime polarization navigation have been extensively researched.However,the polarization light intensity is the fundamental information within the polarization image,and the light intensity at night is 6-8 orders of magnitude lower than that during the day,which increase the noise and the loss of local polarization information due to occlusion,resulting in a significant decrease in the polarization orientation accuracy.Aimed at the problem,a bio-inspired model is introduced to denoise and enhance weak nighttime polarization patterns.Further,to address the issue of outlier interference in the occluded environment during practical application,a fast-fitting method of the solar meridian based on the anti-symmetric distribution of the polarization angle adjusted by Proportional and Differential(PD)control is proposed.The experimental results show that the method proposed in this paper achieves a dynamic orientation error Root Mean Square Error(RMSE)of 0.7°in the weak polarization mode at night and in the presence of local occlusion.The proposed method has strong robustness under weak polarization occlusion at night,and the orientation accuracy is improved by 97%and 80%in comparison to the least squares method,which provides a new method for polarization navigation at night.This effectively improves the robustness and environmental applicability of the bionic polarization compass for nighttime applications.
基金financialsupport from the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0770101)the National Key R&D Program of China(No.2023YFA1508900)the National Natural Science Foundation of China(Nos.22202211 and 52321006).
文摘Achieving rational control over polarization states and color of circularly polarized luminescence(CPL)through simple modulation poses a challenging yet highly practical problem.To address this issue,we developed a mechano-responsive chiral supramolecular system based on a cyclohexanediamide-derived gelator CCPy.This molecule exhibited a strong blue fluorescence accompanied by a distinct CPL signal upon forming a supramolecular gel in toluene.However,upon the application of mechanical force,the gel rapidly transformed into a faintly emissive suspension with a silent CPL signal,along with a notable morphological alteration.Furthermore,by implementing the circularly polarized Förster resonance energy transfer(CP-FRET)strategy,the mechano-responsiveness was effectively imparted to binary systems through the incorporation of dyes Nile red(NR)and coumarin 7(C7),thus realizing mechanical force-switchable green and red CPL systems.It was particularly noteworthy that by adjusting the ratio of CCPy,C7 and NR,a ternary mechanical force-induced CPL ON-OFF switch that emitted a standard white emission was achieved through sequential CP-FRET.Following this,an information encryption experiment was performed.This work provided a paradigm for fabricating smart multi-color and white-light CPL materials.
文摘基于Microfacet理论,当光线照射到粗糙表面时会发生显著的多次镜面反射现象,而传统偏振双向反射分布函数(Polarized Bidirectional Reflectance Distribution Function,pBRDF)未能很好地描述这种现象,为了得到更精确的pBRDF模型,更好地分析材料的偏振特性,本文在包含镜面反射、漫反射和定向漫反射的三分量pBRDF模型基础上,进一步定义了高阶微相位角与一阶相位角的关系。改进后的pBRDF模型不仅考虑了多次镜面反射的几何衰减因子,还引入了微相位角的定义,从而建立了一个更全面的高阶镜面反射pBRDF模型。通过比较不同的pBRDF模型,并结合偏振特性采集装置进行验证,实验结果表明,本文提出的模型优于其他模型,三阶模型效果普遍优于二阶。在偏振图像渲染中,峰值信噪比和结构相似性平均分别提升10.09%和2.97%,呈现更加真实的渲染效果。验证本文提出的高阶镜面反射pBRDF模型能够更准确地描述目标表面的偏振特性。
