Reactive and human-in-the-loop planning and control of multi-robot systems under LTL specifications in dynamic environments

This paper investigates the planning and control problems for multi-robot systems under linear temporal logic (LTL) specifications. In contrast to most of existing literature, which presumes a static and known environment, our study focuses on dynamic environments that can have unknown moving obstacles like humans walking through. Depending on whether local communication is allowed between robots, we consider two different online re-planning approaches. When local communication is allowed, we propose a local trajectory generation algorithm for each robot to resolve conflicts that are detected on-line. In the other case, i.e., no communication is allowed, we develop a model predictive controller to reactively avoid potential collisions. In both cases, task satisfaction is guaranteed whenever it is feasible. In addition, we consider the human-in-the-loop scenario where humans may additionally take control of one or multiple robots. We design a mixed initiative controller for each robot to prevent unsafe human behaviors while guarantee the LTL satisfaction. Using our previous developed ROS software package, several experiments are conducted to demonstrate the effectiveness and the applicability of the proposed strategies

Reactive task planning for multi-robot systems in partial known environment

openThe thesis investigates the planning and control problem for a group of mobile agents moving in a partially known workspace. A task will be assigned to each robot in the form of a linear temporal logic (LTL) formula. First an automaton-based method is introduced for the motion planning of a single agent, which guarantees the satisfaction of the assigned LTL task. Then a model-predictive controller considers state and input constraints leading the agent to a safe navigation. Based on a real scenario of a partial-known environment and agents can have only local sensing, two decentralized control strategies are proposed for online re-planning, which rely on a sampling-based algorithm. The first approach assumes local communication between agents, while the second one exploits a more general communication-free case. Finally, the human-in-the-loop scenario is considered, where a human may additionally take control of the agents, a mixed initiative controller is then implemented to prevent dangerous human behaviors while guarantee the satisfaction of the LTL specification. Using the developed ROS software package, several experiments were carried out to demonstrate the effectiveness and the potential applicability of the proposed strategies.The thesis investigates the planning and control problem for a group of mobile agents moving in a partially known workspace. A task will be assigned to each robot in the form of a linear temporal logic (LTL) formula. First an automaton-based method is introduced for the motion planning of a single agent, which guarantees the satisfaction of the assigned LTL task. Then a model-predictive controller considers state and input constraints leading the agent to a safe navigation. Based on a real scenario of a partial-known environment and agents can have only local sensing, two decentralized control strategies are proposed for online re-planning, which rely on a sampling-based algorithm. The first approach assumes local communication between agents, while the second one exploits a more general communication-free case. Finally, the human-in-the-loop scenario is considered, where a human may additionally take control of the agents, a mixed initiative controller is then implemented to prevent dangerous human behaviors while guarantee the satisfaction of the LTL specification. Using the developed ROS software package, several experiments were carried out to demonstrate the effectiveness and the potential applicability of the proposed strategies