We provc thr uniform asymptotic stability of a new error system, whose transition matrix conntains both a regression vector and a filtered version of that vector. We show that. stahility is under conditions which are different from the usual SPR or small gain rcquiremcuts. We show that this error system arises from the design of adaptive ohservers of time-varying or nonlinear systems.
Mareels, I., Gevers, M., Bastin, G., & Dochain, D. (1987). Exponential convergence of a new error system arising from adaptive observers. Proc 26th IEEE Conference on Decision and Control, 16-19. https://hdl.handle.net/2078.5/127192 (Original work published 1987)