Multirate self-tuning control

A new adaptive control strategy, multi-rate self-tuning control, is presented with consideration of deterministic discrete time plant. The strategy was inspired by the virtual equivalent system methodology for stability and convergence analysis of self-tuning adaptive control systems. By multirate we mean that the adaptive controller will gradually slow down the controller parameter update rate as the parameter estimation error diminishes. Based on a new type of virtual equivalent system and the existing stability results of slow switching systems, the stability and convergence of the multirate self-tuning control system is obtained without requiring the convergence of parameter estimates.