A self-conditioned implementation of switching controllers for smooth transition in multimode systems

This paper deals with an important practical control problem in systems that can switch between different operating modes. We presents a self-conditioned implementation of any two-degree-of-freedom (TDOF) controller which allows a smooth transition when switching between a controller acting in closed-loop and another controller in a bank of idle controllers waiting to take over the control loop. Here, the concept underlying the smoothness of mode transition is that of conditioned transfer which is used to mean that after switching, good tracking performance is ensured albeit a jump at plant input may occur. This notion of conditioned transfer is different from the classical notion of bumpless transfer which refers to the requirement that no bump occurs at the plant input when switching between different controllers. The main feature of our study is that the switching among controllers is driven by the changing dynamics of the controlled-plant and moreover the technique is model-free. This is in contrast with most works reported in the literature on bumpless switching, where switching occurs between controllers driving a plant with fixed dynamics.