A bumpless method for multivariable process controllers via sliding mode

Sliding mode attributes are evaluated for being applied to a bumpless transfer scheme in multiple-input multiple-output (MIMO) process control. Switching from manual to automatic mode is particularly considered, in which case the proposed methodology can be interpreted as building a multivariable sliding mode state-observer of a fictitious offline controller. This approach virtually changes the position of the switch from the controller outputs to internal stages of the controller. Furthermore, it avoids the jumps at the plant inputs even when the switch is performed before the observer transient has extinguished, while at the same time it properly accommodates the remaining controller states