Towards cyber-physical systems robust to communication delays: A differential game approach
This addresses stability issues in interconnected systems like robotics and autonomous vehicles, but it is incremental as it builds on prior differential game and Lyapunov-Krasovskii approaches.
The paper tackled the problem of catastrophic failures in cyber-physical systems due to communication delays by proposing robust controllers for nonlinear time-delay systems, and numerical experiments compared the new control law to existing methods.
Collaboration between interconnected cyber-physical systems is becoming increasingly pervasive. Time-delays in communication channels between such systems are known to induce catastrophic failure modes, like high frequency oscillations in robotic manipulators in bilateral teleoperation or string instability in platoons of autonomous vehicles. This paper considers nonlinear time-delay systems representing coupled robotic agents, and proposes controllers that are robust to time-varying communication delays. We introduce approximations that allow the delays to be considered as implicit control inputs themselves, and formulate the problem as a zero-sum differential game between the stabilizing controllers and the delays acting adversarially. The ensuing optimal control law is finally compared to known results from Lyapunov-Krasovskii based approaches via numerical experiments.