六轴工业机器人先验引导RRT*避障轨迹算法研究

针对六轴工业机器人装配避障路径运动问题,研究了机器人整体避障运动路径规划方法,提出一种RRT*改进算法;算法以RRT*算法为基础,在障碍物建模中引入包围盒算法,加入对机器人各轴与障碍物的碰撞检测;在路径规划中加入对随机点生成方向与树枝生长方向的先验引导机制,优化了算法路径长度与路径搜寻效率;通过Matlab进行了试验验证,结果表明与标准RRT*算法相比,先验引导RRT*算法缩短路径长度14%左右,且满足机器人末端路径与手臂各轴的避障需求。     

Robust estimation of planar surfaces using spatio-temporal RANSAC for applications in autonomous vehicle navigation

A fundamental problem in autonomous vehicle navigation is the identification of obstacle free space in cluttered and unstructured environments. Features such as walls, people, furniture, doors and stairs, etc are potential hazards. The approach taken in this paper is motivated by the recent development on infra-red time-of-flight cameras that provide video frame rate low resolution depth maps. We propose to exploit the temporal information content provided by the high refresh rate of such cameras to overcome the limitations due to low spatial resolution and high depth uncertainty and aim to provide robust and accurate estimates of planar surfaces in the environment. These surfaces’ estimates are then used to provide statistical tests to identify obstacles and dangers in the environment. Classical 3D spatial RANSAC is extended to 4D spatio-temporal RANSAC by developing spatio-temporal models of planar surfaces that incorporate a linear motion model as well as linear environment features. A 4D-vector product is used for hypotheses generation from data that is randomly sampled across both spatial and temporal variations. The algorithm is fully posed in the spatio-temporal representation and there is no need to correlate points or hypothesis between temporal images. The proposed algorithm is computationally fast and robust for estimation of planar surfaces in general and the ground plane in particular. There are potential applications in mobile robotics, autonomous vehicular navigation, and automotive safety systems. The claims of the paper are supported by experimental results obtained from real video data for a time-of-flight range sensor mounted on an automobile navigating in an undercover parking lot.     

Neural network approach to acquiring free-gait motion of quadruped robots in obstacle avoidance

In obstacle avoidance by a legged mobile robot, it is not necessary to avoid all of the obstacles by turning only, because it can climb or stride over some of them, depending on the obstacle configuration and the state of the robot, unlike a wheel-type or a crawler-type robot. It is thought that mobility efficiency to a destination is improved by crawling over or striding over obstacles. Moreover, if robots have many legs, like 4-legged or 6-legged types, then the robot's movement range is affected by the order of the swing leg. In this article a neural network (NN) is used to determine the action of a quadruped robot in an obstacle-avoiding situation by using information about the destination, the obstacle configuration, and the robot's self-state. To acquire a free gait in static walking, the order of the swing leg is realized using an alternative NN whose inputs are the amount of movement and the robot's self-state. The design parameters of the former NN are adjusted by a genetic algorithm (GA) off-line. This work was presented in part at the 9th International Symposium on Artificial Life and Robotics, Oita, Japan, January 28–30, 2004     

多机器人系统中的动态避碰规划

研究冲突区域中多机器人间的协调和避碰问题。采用集中-分布相结合的规划方法，根据系统的拓扑结构为每个机器人规划路径，在冲突区域内使用优先级策略对机器人的运动特征进行分布式规划。通过上下层智能的融合，提高整个系统的智能。     

VR-GIS技术在高等级公路建设中的应用

以连霍国道主干线(GZ45)牛背(宝鸡)至天水段高速公路建设为例,主要从数据预处理、三维虚拟现实数字模型建立、工程填挖方计算与分析、三维巡航模拟飞行等几个方面,详细探讨了利用数字高程模型(DEM)、数字正射影像图(DOM)、数字线划图(DLG)等基础地理空间数据及VR-GIS技术,为高速公路方案比选、选线及构筑物设计、环境保护、工程可行性分析提供可靠决策依据的技术方法。     

新型智慧城市软件基础设施

现代城市的信息化建设伴随着"随业务而定制、随需求而变化"的软件模式.城市向数字化升级过程中,定制化需求以更快的速度发展;同时,城市治理与市民服务对覆盖率、效率、质量的要求持续提升.我们需要一套有效的、系统性的软件基础设施来满足这种"更快速、更精准、更多样、随需而变"的城市数字化业务需求.文章首先从宏观层面简单回顾了过去...     

N—丁基马来酰亚胺的微乳液聚合研究：Ⅰ合成与表征

配制了ＳＤＳ／ＮＢＭＩ／Ｈ２Ｏ三组分Ｏ／Ｗ微乳液。以过硫酸钾为引发剂,首次用微乳液聚合法合成了聚Ｎ－丁基马来酰亚胺,并用ＩＲ、ＤＳＣ、ＴＧ等对聚合物进行了表征     

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四川盆地志留系在加里东运动抬升剥蚀中仅残留下统地层，文章旨在研究其层序特征，指出有利勘探区。应用层序地层学方法，识别志留系进行层序界面，划分划分出5个层序、10个体系域，建立等时地层格架，分析储集层展布规律。志留系层序由加积—退积的准层序组构成海侵体系和加积—进积的准层序组构成的高位体系域组成。储集岩有滨岸砂坝相的砂质岩和生物礁及生物浅滩碳酸盐岩，川东以“小河坝砂岩”碎屑岩储集层为主；川南以生物礁及生物浅滩灰岩储集层为主。     

障碍物对管道中预混火焰压力发展的实验研究

研究了管路中甲烷爆炸过程中火焰传播规律和加速机理以及由于障碍物引起的火焰加速而导致的管内压力上升现象。研究结果表明,障碍物的存在对甲烷爆炸过程中火焰传播规律以及管内压力的影响十分巨大,障碍物的存在将使瓦斯爆炸过程中火烙的传播速度迅速提高,导致压力大幅度上升。加速作用的机理主要是由于障碍物诱导的湍流区对燃烧过程的正反馈造成的。