Reference tracking of uncertain nonlinear Multi-Input Multi-Output quantized systems using L1 adaptive control

This paper presents an L₁ adaptive controller for nonlinear Multi-Input Multi-Output (MIMO) systems with unmatched uncertainties in the presence of both state and input quantization. Uniform quantization is employed with hysteresis, and the closed-loop system output is shown to track that of a stable reference system. Performance bounds for system´s state and input signals are obtained, and it is shown that the system performance can be systematically improved by increasing the adaptation rate or improving the state and input quantization. Simulations are provided to corroborate the theoretical results.