Purpose Large-scale and precise three-dimensional (3D) map play an important role in autonomous driving and robot positioning. However, it is difficult to get accurate poses for mapping. On one hand, the global positioning system (GPS) data are not always reliable owing to multipath effect and poor satellite visibility in many urban environments. In another hand, the LiDAR-based odometry has accumulative errors. This paper aims to propose a novel simultaneous localization and mapping (SLAM) system to obtain large-scale and precise 3D map. Design/methodology/approach The proposed SLAM system optimally integrates the GPS data and a LiDAR odometry. In this system, two core algorithms are developed. To effectively verify reliability of the GPS data, VGL (the abbreviation of Verify GPS data with LiDAR data) algorithm is proposed and the points from LiDAR are used by the algorithm. To obtain accurate poses in GPS-denied areas, this paper proposes EG-LOAM algorithm, a LiDAR odometry with local optimization strategy to eliminate the accumulative errors by means of reliable GPS data. Findings On the KITTI data set and the customized outdoor data set, the system is able to generate high-precision 3D map in both GPS-denied areas and areas covered by GPS. Meanwhile, the VGL algorithm is proved to be able to verify reliability of the GPS data with confidence and the EG-LOAM outperform the state-of-the-art baselines. Originality/value A novel SLAM system is proposed to obtain large-scale and precise 3D map. To improve the robustness of the system, the VGL algorithm and the EG-LOAM are designed. The whole system as well as the two algorithms have a satisfactory performance in experiments.

Energy conversion| Polymers | Binder | Polyanions| AdsorptionSulfur has been paid close attention by the research and manufacturing as a cathode material for lithium-sulfur batteries (LSB) in recent decade because it has high specific capacity and low cost. But the low utilization of active materials and serious shuttle phenomenon inhibit its commercialization process. In this work, for the first time, water reducers are reported as multifunctional binders to address the above problems to enhance the performance of LSB. Due to the synthetic actions of the water reducer binder, such as highly dispersing effect and good chemical trapping function, commercial sulfur powders are directly used as cathodes, and much better electrochemical performance compared to using the conventional binder polyvinylidene fluoride (PVDF) was obtained, among which the sulfur cathode with sulfonated melamine formaldehyde (SMF) water reducer binder exhibits a high reversible capacity of 625.5 mA•h•g -1 after 200 cycles at 1 C and the cathode with polycarboxylic acid (PC) water reducer binder even demonstrates a high area specific capacity of 5 mA•h•cm -2 at high sulfur loading of 5 mg•cm -2. These low-cost water reducers are a promising binder for LSB in the future.

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