College of Mechatronics and Automation, National University of Defense Technology, Changsha 410073, China.
Nanofabrication Laboratory, Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.
Sensors (Basel). 2017 Nov 14;17(11):2623. doi: 10.3390/s17112623.
Animals, such as Savannah sparrows and North American monarch butterflies, are able to obtain compass information from skylight polarization patterns to help them navigate effectively and robustly. Inspired by excellent navigation ability of animals, this paper proposes a novel image-based polarized light compass, which has the advantages of having a small size and being light weight. Firstly, the polarized light compass, which is composed of a Charge Coupled Device (CCD) camera, a pixelated polarizer array and a wide-angle lens, is introduced. Secondly, the measurement method of a skylight polarization pattern and the orientation method based on a single scattering Rayleigh model are presented. Thirdly, the error model of the sensor, mainly including the response error of CCD pixels and the installation error of the pixelated polarizer, is established. A calibration method based on iterative least squares estimation is proposed. In the outdoor environment, the skylight polarization pattern can be measured in real time by our sensor. The orientation accuracy of the sensor increases with the decrease of the solar elevation angle, and the standard deviation of orientation error is 0 . 15 ∘ at sunset. Results of outdoor experiments show that the proposed polarization navigation sensor can be used for outdoor autonomous navigation.
动物，如萨凡纳麻雀和北美黑脉金斑蝶，能够从天空的偏振光模式中获取罗盘信息，帮助它们有效地进行导航。受动物出色导航能力的启发，本文提出了一种新颖的基于图像的偏振光罗盘，它具有体积小、重量轻的优点。首先，介绍了由电荷耦合器件（CCD）相机、像素化偏振器阵列和广角镜头组成的偏振光罗盘。其次，提出了天空偏振光模式的测量方法和基于单次散射瑞利模型的定向方法。第三，建立了传感器的误差模型，主要包括 CCD 像素的响应误差和像素化偏振器的安装误差。提出了一种基于迭代最小二乘估计的校准方法。在户外环境中，我们的传感器可以实时测量天空的偏振光模式。传感器的定向精度随着太阳仰角的降低而增加，日落时定向误差的标准偏差为 0. 15 ∘ 。户外实验结果表明，所提出的偏振导航传感器可用于户外自主导航。
