基于记忆矩阵A*引导域的VHF算法改进策略

An Improved Strategy of VHF Algorithm Based on Memory Matrix and A* Guided Domain

摘要:

针对机器人采用VFH算法避障容易陷入局部死区的问题，提出为机器人增加记忆地图的方法.在面对未知环境时，采用了一种新的自适应阈值策略，在一定程度上避开局部死区抵达目标点，同时在首次避障时生成记忆地图.在二次避障过程中通过记忆地图产生低分辨率A*引导域，使用改进的代价函数，使A*引导域与VFH算法有效结合，以较优的路径完成避障过程，同时能实时适应周围环境的变化.最后，在MATLAB上针对不同环境进行算法仿真对比.实验结果表明，使用新的自适应阈值策略能在未知环境下完成避障过程并产生记忆地图；在记忆地图的基础上使用A*域的引导，能使机器人适应周围环境变化的同时以较优的路径顺利到达目标位置.

Abstract:

To solve the problem of easily falling into the local dead zone when the robot avoids obstacles with VFH algorithm, a method is proposed to add memory maps for robots. When facing the unknown environment, the improved strategy of using adaptive threshold is used to avoid the local dead zone and reach the target point, meanwhile, a memory map is generated on which a lowresolution A* guided domain is then produced and the cost function is improved to effectively combine the A* guided domain with the VFH algorithm to complete obstacle avoidance with a better path and adapt to changes in the surrounding environment in real time. Finally, the algorithm is verified in different environments. The experimental results show that the strategy of using adaptive threshold can complete obstacle avoidance and generate memory map in unknown environment; based on memory map and the guidance of the A* domain, the robot can adapt to the changes of the surrounding environment and smoothly reach the target.