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61.
近年来无人机在各个领域的应用逐渐兴起,尤其是在物流运输领域发展迅速。在物流运输领域的应用主要是与车辆进行组合运输,国内外的学者针对无人机和车辆组合运输的路径规划问题进行了许多研究。主要论述了目前车辆和无人机组合运行的4种模式,包括车辆支持无人机运行模式、无人机支持车辆运行模式、无人机与车辆独立的运行模式、无人机和车辆同步的运行模式。探究了目前无人机和车辆组合路径规划问题考虑的因素,包括无人机电池电量、运送包裹数量和时间窗等。对有无人机参与的车辆路径规划问题的目标优化进行了总结,目前的研究主要分为3类,包括考虑最短配送时间、最小总成本和多目标规划。这些研究对未来无人机配送问题的研究具有重要的指导意义。 相似文献
62.
《中国航空学报》2023,36(3):368-381
Formation control of fixed-wing aerial vehicles is an important yet rarely addressed problem because of their complex dynamics and various motion constraints, such as nonholonomic and velocity constraints. The guidance-route-based strategy has been demonstrated to be applicable to fixed-wing aircraft. However, it requires a global coordinator and there exists control lag, due to its own natures. For this reason, this paper presents a fully distributed guidance-route-based formation approach to address the aforementioned issues. First, a hop-count scheme is introduced to achieve distributed implementation, in which each aircraft chooses a neighbor with the minimum hop-count as a reference to generate its guidance route using only local information. Next, the model predictive control algorithm is employed to eliminate the control lag and achieve precise formation shape control. In addition, the stall protection and collision avoidance are also considered. Finally, three numerical simulations demonstrate that our proposed approach can implement precise formation shape control of fixed-wing aircraft in a fully distributed manner. 相似文献
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64.
Collaborative Navigation in an Unfamiliar Environment with People Having Different Spatial Aptitudes
This study addressed the issue of collaborative navigation by examining the types of information communicated in the processes of direction giving and receiving between people who guided each other simultaneously to a destination over the cell phone in a novel environment. When paired with a partner whose sense of direction differed greatly from their own, people found the collaboration difficult and took a longer time to verbally direct the partner to the destination. Landmarks that people used in giving navigational instructions differed depending on sense of direction. People with a good sense of direction adjusted route directions to their partners' wayfinding ability. Results from a detailed qualitative analysis of participants' verbal protocols and implications for personalized navigation tools are discussed. 相似文献
65.
Abstract This paper addresses changes of spatial granularity in route directions in relation to information needs in multimodal traveling. We outline a model of variability in granularity and apply this model to empirical data. Results reveal that linguistic route directions produced by humans as well as automatically generated web-based services provide the most crucial route elements in hierarchically structured ways that reflect the salient structure imposed by multimodal traveling. However, although the web-based information is impressively comprehensive, human route directions exhibit more flexibility regarding switches of place-related granularity, and they provide more detailed information at complex locations or decision points. 相似文献
66.
Abstract The nature of route learning in terms of the memorizing of landmarks was investigated. In Experiment 1, participants memorized landmarks while being guided through a computer-simulated hallway (dynamic, with spatial context), or while viewing the landmarks one by one in front of a black background (static, without context). Two more conditions completed the 2 × 2 design. One condition preserved the dynamic landmark viewing properties (observers approached each object, passed it, turned to the next object, and so on), but the background was black (dynamic, without context). In the other condition the observer saw a stationary display of each object within a hallway, but did not approach the object (static, with context). Serial recall was much better after viewing the landmarks in the dynamic presentation format with spatial context than in the other conditions. Experiment 2 showed that the superior performance in the dynamic condition with context was abolished when all hallway segments were equally long. This implies that metric information is a component of route knowledge at a very early stage, which is incompatible with the dominant framework, but is compatible with the alternative framework for spatial microgenesis. 相似文献
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68.
Although considerations of discourse coherence and cognitive processing suggest that communicators should adopt consistent perspectives when describing spatial scenes, in many cases they switch perspectives. Ongoing research examining cognitive costs indicates that these are small and exacted in establishing a mental model of a scene but not in retrieving information from a well-known scene. A perspective entails a point of view, a referent object, and terms of reference. These may change within a perspective, exacting cognitive costs, so that the costs of switching perspective may not be greater than the costs of maintaining the same perspective. Another project investigating perspective choice for self and other demonstrates effects of salience of referent object and ease of terms of reference. Perspective is mixed not just in verbal communications but also in pictorial ones, suggesting that at times, switching perspective is more effective than maintaining a consistent one. 相似文献
69.
动态空域配置旨在通过对各类型空域功能块的设计、构架、配置和使用,实现空域的动态配置功能,使管制空域灵活地匹配空中交通实际变化的需求。在此概念下建立了以最小运营成本为目标的航路调整规划模型,在模型中考虑某些航路段可以动态地开关-闭合,引入动态航路的开放成本和使用成本,以最短开放时间、最大管制负荷和航路复杂度、安全性为约束条件,采取改进的遗传算法进行求解,验证了模型的正确性和可行性。计算结果表明:用模型制定的优化策略,充分利用了空域资源,减少了延误损失,总的航班运营成本减少了15%。 相似文献
70.
为提高多架无人作战飞机(UCAV)存复杂环境下的协同巡逻效率,根据先验信息将环境划分为关注程度不等的未知区域、已知区域和禁飞区域,在航路规划算法中引入搜索回报函数和加权平均距离,加强对高关注度区域的巡逻力度,改善UCAV的空间分布。应用粒子群算法对航路规划模型进行了仿真,结果表明提出的协同巡逻航路规划算法有效 相似文献