Nonlinear observer design for a varying-order switched system with application to heat exchangers

In this paper, a switched nonlinear observer design for a varying-order switched system is presented with convergence conditions. It has been implemented to estimate the state variables of the evaporator under varying refrigerant phase transitions which is a switched system with varying order. The convergence of the switched observer is proved using contraction theory. The switched observer design is validated by numerical simulations.