Reactive Task Allocation and Planning of A Heterogeneous Multi-Robot System

This paper takes the first step towards a reactive, hierarchical multi-robot task allocation and planning framework given a global Linear Temporal Logic specification. In our scenario, legged and wheeled robots collaborate in a heterogeneous team to accomplish a variety of navigation and delivery tasks. However, all robots are susceptible to different types of disturbances including locomotion failures, human interventions, and obstructions from the environment. To address these disturbances, we propose task-level local and global reallocation strategies to efficiently generate updated action-state sequences online while guaranteeing the completion of the original task. In addition, these task reallocation approaches eliminate reconstructing the entire plan or resynthesizing a new task. Lastly, a Behavior Tree execution layer monitors different types of disturbances and employs the reallocation methods to make corresponding recovery strategies. To evaluate this planning framework, dynamic simulations are conducted in a realistic hospital environment with a heterogeneous robot team consisting of quadrupeds and wheeled robots for delivery tasks.