ALPi/MPP/FeCo-MOF协效阻燃PBT/PP复合材料的研究

制备了一种双金属协效阻燃剂(FeCo-MOF),研究了二乙基次膦酸铝(ALPi)/三聚氰胺聚磷酸盐(MPP)/FeCo-MOF协效阻燃聚对苯二甲酸丁二醇酯/聚丙烯(PBT/PP)复合材料的性能。结果表明：当ALPi/MPP/FeCo-MOF的质量比为13.00∶6.50∶0.60时,阻燃PBT/PP复合材料的极限氧指数为32%,UL-94垂直燃烧阻燃等级为V-0级,800℃时残炭率达8.97%。     

Detection of loop closure in visual SLAM:a stacked assorted auto-encoder based approach

The current mainstream methods of loop closure detection in visual simultaneous localization and mapping (SLAM) are based on bag-of-words (BoW). However, traditional BoW-based approaches are strongly affected by changes in the appearance of the scene, which leads to poor robustness and low precision. In order to improve the precision and robustness of loop closure detection, a novel approach based on stacked assorted auto-encoder (SAAE) is proposed. The traditional stacked auto-encoder is made up of multiple layers of the same autoencoder. Compared with the visual BoW model, although it can better extract the features of the scene image, the output feature dimension is high. The proposed SAAE is composed of multiple layers of denoising auto-encoder, convolutional auto-encoder and sparse auto-encoder, it uses denoising auto-encoder to improve the robustness of image features, convolutional auto-encoder to preserve the spatial information of the image, and sparse auto-encoder to reduce the dimensionality of image features. It is capable of extracting low to high dimensional features of the scene image and preserving the spatial local characteristics of the image, which makes the output features more robust. The performance of SAAE is evaluated by a comparison study using data from new college dataset and city centre dataset. The methodology proposed in this paper can effectively improve the precision and robustness of loop closure detection in visual SLAM.     

基于原图-光照不变图视觉词典改进的闭环检测方法

当机器人所处环境光照发生变化时,基于传统视觉词典的闭环检测算法性能会降低,容易出现感知混叠和感知变异,从而判断出假闭环.该文首先通过原彩色图像生成只与光源有关的光照不变图,然后生成原图-光照不变图的视觉词典,对每帧图像计算两个直方图和相似性得分,通过最终的得分矩阵来判断是否闭环.实验结果表明,与传统的视觉词典法相比,该...     

PPO/SEBS/SEBS-g-MAH共混物的阻燃性能研究

以苯乙烯-乙烯/丁二烯-苯乙烯嵌段共聚物(SEBS)为弹性体改性剂，SEBS-g-MAH为相容剂，红磷和Mg(OH)₂作为阻燃剂，采用双螺杆挤出技术，制备了阻燃聚苯醚(PPO)/SEBS/SEBS-g-MAH共混物。结果表明：当红磷用量为15份时，Mg(OH)₂仅用80份，PPO/弹性体共混物的极限氧指数(LOI)就能达到28%,燃烧等级达UL94 V-0级，同时燃烧时的热释放速率(HRR)及生烟速率(SPR)均大幅降低。