Cyber-Physical Multi-Robot Formation with a Communication Delays and a Virtual Agent Approach

A cyber-physical multi-robot system integrates robotic agents that share data over communication networks in real time to achieve common objectives by making decisions collectively based on the knowledge of their surroundings. This work introduces a formation control strategy for two groups of mobile robots placed in two separate workspaces connected by a communication network. The control technique generates two similar formations on each workspace using virtual agents that mirror the behavior of the corresponding physical robot in the opposite workspace. Control laws are derived for a single integrator and unicycle-type real and virtual robots that converge to the desired formation, even in the presence of communication delays. The numerical simulations performed show the convergence of the control strategy. A low-cost cyber-physical micro-robot platform was developed to run experiments with real robots. The setup uses a camera as a position and orientation sensor and the MQTT protocol for server communication and data exchange. Results obtained on this platform show the feasibility of the approach in an actual physical setting.