The convergence of parameter estimates is not necessary for a general self-tuning control system- stochastic plant

This paper is concerned with the stability and convergence of a general stochastic self-tuning control (STC) system, which consists of arbitrary control strategy and arbitrary estimation algorithm. The necessary conditions required for global stability and convergence are relaxed, i.e., the convergence of parameter estimates is removed. The key point is that with the help of virtual equivalent system (VES) concept, the original nonlinear dominant (nonlinear in structure) problem of stochastic STC is converted to a linear dominant (linear in structure) problem - stochastic slow switching control system.