Due to the requirements for mobile robots to search or rescue in unknown environments, reactive navigation which plays an essential role in these applications has attracted increasing interest. However, most existing reactive methods are vulnerable to local minima in the absence of prior knowledge about the environment. This paper aims to address the local minimum problem by employing the proposed boundary gap (BG) based reactive navigation method. Specifically, the narrowest gap extraction algorithm (NGEA) is proposed to eliminate the improper gaps. Meanwhile, we present a new concept called boundary gap which enables the robot to follow the obstacle boundary and then get rid of local minima. Moreover, in order to enhance the smoothness of generated trajectories, we take the robot dynamics into consideration by using the modified dynamic window approach (DWA). Simulation and experimental results show the superiority of our method in avoiding local minima and improving the smoothness.

中文翻译：

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未知环境中基于边界间隙的反应式导航

由于移动机器人在未知环境中进行搜索或救援的要求，在这些应用中起重要作用的反应式导航引起了越来越多的兴趣。但是，大多数现有的反应方法在缺乏有关环境的先验知识的情况下容易受到局部极小值的影响。本文旨在通过采用基于边界间隙（BG）的反应式导航方法来解决局部最小问题。具体而言，提出了最窄间隙提取算法（NGEA），以消除不适当的间隙。同时，我们提出了一种称为边界间隙的新概念，该概念使机器人能够跟随障碍物边界并摆脱局部极小值。此外，为了增强生成轨迹的平滑性，我们使用改进的动态窗口方法（DWA）考虑了机器人的动力学特性。仿真和实验结果表明，该方法在避免局部极小和提高平滑度方面具有优势。