A Hierarchical Decoupling Approach for Fast Temporal Logic Motion Planning

Fast motion planning is of great significance, especially when a timely mission is desired. However, the complexity of motion planning can grow drastically with the increase of environment details and mission complexity. This challenge can be further exacerbated if the tasks are coupled with the desired locations in the environment. To address these issues, this work aims at fast motion planning problems with temporal logical specifications. In particular, we develop a hierarchical decoupling framework that consists of three layers: the high-level task planner, the decoupling layer, and the low-level motion planner. The decoupling layer is designed to bridge the high and low layers by providing necessary information exchange. Such a framework enables the decoupling of the task planner and path planner, so that they can run independently, which significantly reduces the search space and enables fast planing in continuous or high-dimension discrete workspaces. In addition, the implicit constraint during task-level planning is taken into account, so that the low-level path planning is guaranteed to satisfy the mission requirements. Numerical simulations demonstrate at least one order of magnitude speed up in terms of computational time over existing methods.