Hierarchical Reinforcement Learning for Safe Mapless Navigation with Congestion Estimation
This addresses navigation challenges for robots in congested indoor settings, representing an incremental improvement over existing methods.
The paper tackles the problem of safe mapless navigation in indoor environments with local minima by introducing a hierarchical reinforcement learning framework with a sub-goal update mechanism and obstacle encoding, achieving strong performance in simulations and physical experiments on a TurtleBot3 robot.
Reinforcement learning-based mapless navigation holds significant potential. However, it faces challenges in indoor environments with local minima area. This paper introduces a safe mapless navigation framework utilizing hierarchical reinforcement learning (HRL) to enhance navigation through such areas. The high-level policy creates a sub-goal to direct the navigation process. Notably, we have developed a sub-goal update mechanism that considers environment congestion, efficiently avoiding the entrapment of the robot in local minimum areas. The low-level motion planning policy, trained through safe reinforcement learning, outputs real-time control instructions based on acquired sub-goal. Specifically, to enhance the robot's environmental perception, we introduce a new obstacle encoding method that evaluates the impact of obstacles on the robot's motion planning. To validate the performance of our HRL-based navigation framework, we conduct simulations in office, home, and restaurant environments. The findings demonstrate that our HRL-based navigation framework excels in both static and dynamic scenarios. Finally, we implement the HRL-based navigation framework on a TurtleBot3 robot for physical validation experiments, which exhibits its strong generalization capabilities.