  Integrated Sensing and Communication (ISAC) is an emerging technology that
integrates wireless sensing and communication into a single system,
transforming many applications, including cooperative mobile robotics. However,
in scenarios where radio communications are unavailable, alternative approaches
are needed. In this paper, we propose a new optical ISAC (OISAC) scheme for
cooperative mobile robots by integrating camera sensing and screen-camera
communication (SCC). Unlike previous throughput-oriented SCC designs that work
with stationary SCC links, our OISAC scheme is designed for real-time control
of mobile robots. It addresses new problems such as image blur and long image
display delay. As a case study, we consider the leader-follower formation
control problem, an essential part of cooperative mobile robotics. The proposed
OISAC scheme enables the follower robot to simultaneously acquire the
information shared by the leader and sense the relative pose to the leader
using only RGB images captured by its onboard camera. We then design a new
control law that can leverage all the information acquired by the camera to
achieve stable and accurate formations. We design and conduct real-world
experiments involving uniform and nonuniform motions to evaluate the proposed
system and demonstrate the advantages of applying OISAC over a benchmark
approach that uses extended Kalman filtering (EKF) to estimate the leader's
states. Our results show that the proposed OISAC-augmented leader-follower
formation system achieves better performance in terms of accuracy, stability,
and robustness.
