A robust approach to adaptive control algorithms

In this note, a robust approach is proposed for various modified adaptive control algorithms to counteract the presence of bounded disturbances. A key feature of the approach is that when using it, neither the knowledge of the upper bound on the disturbance nor the knowledge of the upper bound on the norm of the matching controller parameters is required for time implementation of those adaptive control algorithms modified with dead zone, constrained estimation, and σ-modification. The stability and convergence results of the resulting algorithms are provided