Study on the parameters estimation based on interval observer

The method using interval observers to estimate parameters have been verified in linear system and simple nonlinear cooperative system (elements of Jacobian matrix on the non-diagonal are non-negative). We can see the concept about cooperative system in references, but it has some limitations for reality system. This paper tries to use interval observer method for more general nonlinear system which is not a cooperative system. The Jacobian matrix of the observer can meet the condition of cooperative system by properly choosing the gain of the observer, hence the observer becomes a monotonic observer. By using this method, one can determine whether the parameter interval contains the value of the system parameter. The feasibility of this idea is illustrated by the simulation example using a nonlinear dynamic system model.