Mobile Robot Path Planning Using Multi-Layer Configuration Space Maps

The robot performs preliminary path planning and obstacle mapping before attempting to return to the docking station. The configuration space map is built in advance by expanding obstacle areas, and multiple candidate paths are generated beforehand. When the robot needs to return, it can immediately execute the pre-planned path without waiting for signal availability, thus ensuring reliable return even when signals are unavailable.

The patent introduces an intermediary mechanism - the configuration space map and path planning system - that mediates between the robot and the docking station. Instead of directly relying on signal reception for localization, the robot uses the pre-built configuration space map to navigate. This intermediary allows the robot to return to the docking station through path execution rather than signal-based localization, resolving the contradiction between reliability and signal reception adaptability.

The patent applies partial action by expanding obstacle areas by different thicknesses to create multiple levels of configuration space maps. Instead of creating one highly detailed map, the system creates progressively detailed maps (first configuration space map with larger expansion, second configuration space map with smaller expansion). This allows the robot to use coarser maps for general navigation and only generate detailed paths when necessary, reducing overall computation time while maintaining path accuracy.

The path generation process is segmented into multiple stages corresponding to different configuration space maps. The robot first generates paths using the first configuration space map (larger obstacle expansion), and only when needed does it generate paths using the second configuration space map (smaller expansion). This segmentation allows the system to balance computational load and path accuracy, avoiding the need to always generate highly detailed paths.

The patent implements a dynamic configuration space map system where the obstacle expansion thickness can be adjusted based on navigation needs. The system dynamically switches between the first configuration space map (larger expansion) and the second configuration space map (smaller expansion) depending on the situation. This dynamic adjustment provides adaptability for different navigation scenarios while maintaining a relatively simple overall system structure, as the switching logic is straightforward.

The multiple configuration space maps serve universal purposes in the path generation system. Both the first and second configuration space maps can be used for different types of navigation tasks - the first map for general area exploration and avoidance, the second map for precise path following. This multi-functionality allows a single path generation unit to handle diverse navigation scenarios without requiring separate specialized systems, balancing complexity and versatility.