Robustifying Prescribed Performance Controllers Against Control Input Data Losses

For a class of nonlinear networked control systems (NCSs), we consider designing a control architecture to render controllers constructed via the prescribed performance control (PPC) methodology robust, against the presence of control input data losses, while preserving, to a large extend, the performance attributes achieved in their absence. To succeed the aforementioned, the PPC designed controller is smoothly reconfigured to a safe mode of operation, whenever the NCS states evolve close to the user-defined performance bounds. The latter scheme effectively permits performance bounds crossing, thus avoiding the appearance of PPC-instability, attributed to its operational philosophy that resembles barrier functions in constraint optimization. Performance bounds crossing is undoubtedly highly expected, as during the data loss phenomenon the NCS practically operates in open-loop. Even though the duration of the data loss phenomenon and its appearance are unknown, no detection mechanism is incorporated to acquire such knowledge. Simulation studies clarify and verify the theoretical findings.