主动万向脚轮式全向移动机器人的关节空间多传感器信息融合算法

鉴于主动万向脚轮式全向移动机器人运动学矩阵与其脚轮转向关节的位置有关,因此脚轮的运动误差会同时降低机器人的里程计和速度控制精度.因传统的工作空间信息融合算法无法有效提高脚轮运动精度,本文提出一种基于卡尔曼滤波的关节空间多传感器信息融合算法.新算法首先预测机器人的工作空间状态,然后通过逆向运动学将其解算到关节空间,随之在关节空间内进行数据融合,以提高脚轮运动精度,最后利用脚轮运动的最优估计来更新各关节角度和机器人里程计信息.仿真实验验证了该算法可有效减少脚轮运动的误差,使机器人的运动学矩阵更接近其真实状态,从而提升了机器人的里程计和速度控制精度.     

Ultra-broadband absorber based on cascaded nanodisk arrays

An ultra-broadband perfect absorber consisting of cascaded nanodisk arrays is demonstrated by placing insulator-metal-insulator-metal nanodisks on insulator-metal film stacks. The absorber shows over 90% absorption in a wavelength range between 600 nm and 4000 nm under transverse magnetic (TM) polarization, with an average absorptivity of 91.5% and a relative absorption bandwidth of 147.8%. The analysis of the electric field and magnetic field show that the synergy of localized surface plasmons, propagating surface plasmons, and plasmonic resonant cavity modes leads to the ultra-broadband perfect absorption, which accords well with the results of impedance-matched analysis. The influences of structural parameters and different metal materials on absorption performance are discussed. Furthermore, the absorber is polarization-independent, and the absorption remains more than 90% at a wide incident angle up to 40° under TE polarization and TM polarization. The designed ultra-broadband absorber has promising prospects in photoelectric detection and imaging.