Robust LiDAR Localization on an HD Vector Map without a Separate Localization Layer - Chi Zhang; Liwen Liu; Zhoupeng Xue; Kun Guo; Kuiyuan Yang; Rui Cai; Zhiwei Li (IEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2021, Prague, Czech Republic, September 27 - Oct. 1, 2021, 2021)