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Robust data association is a core problem of visual odometry, where image-to-image correspondences provide constraints for camera pose and map estimation. Current state-of-the-art visual semantic odometry uses local map points semantics, building semantic residuals associated with all classes to realize medium-term tracking of points. Considering the problem of inefficient semantic data associations and redundant semantic observation likelihood model in the visual semantic odometry, we propose a visual odometry, Local Semantic Odometry (LVSO), which is integrated with medium-term semantic constraints based on local nearest neighbor distance model.

To solve the problems of ethnic size difference and model simplification in existing research, three kinds of lower limb finite element models of adult male with percentile 5, 50 and 95 were established based on the size characteristics of Chinese human body.The bionic reliability of the models was verified according to three different lower limb biomechanical experiments. Through the simulation analysis of pedestrian lower limb with different percentiles in side impact, it was found that in the pedestrian low-speed side impact accident, the lower percentile human body has a higher risk of lower limb injury,especially the injury of knee joint. The soft foam structure can play a better cushioning and energy absorption role in the impact process. The response parameters decrease with the decrease of percentile.In addition,the soft foam can significantly reduce the risk of lower limb injuries when impacting the lower limbs laterally at low speed.

As the power of electric vehicles (EVs), lithium-ion batteries (LIBs) are subjected to a variety of mechanical loads during electrochemical operation. Under this operating environment, lithium-ion batteries are at risk of internal short circuit, thermal runaway and even fire, threatening the safety of electric vehicles. The purpose of this paper is to investigate the mechanical behaviors and failure mechanisms of the battery separator to improve the safety of lithium-ion batteries under mechanical loads. In this study, uniaxial tensile, through-thickness compression and biaxial punch tests were performed to characterize two types of separators, dry-processed polypropylene (PP) separators and wet-processed ceramic-coated separators, and to analyze and compare their mechanical properties and failure modes. The comprehensive mechanical tests show that the failure modes of the different separator types are different, with the more anisotropic separator having more complex failure modes.