Improved robust gradient algorithm for time varying systems with robust min-max estimation resetting and dead zone

A new algorithm named improve robust gradient estimation algorithm with robust min-max estimation resetting and dead zone is presented in this paper based on the robust min-max estimation algorithm and gradient estimation algorithm. The selection criteria of the switching threshold between the min-max estimation algorithm and gradient algorithm are given by using robust min-max estimation method. The improved algorithm solves the tracking problem of time-varying system with fast parameter changes better, which is very difficult to the general gradient estimation algorithm. This improved algorithm is robust and is not sensitive to the noise. Its good performance is verified by simulation studies carried out on a dynamic fermentation process.