Nonlinear Dynamic Measurement System Modeling

This thesis mainly analyzes the property of Duffing system, which is the most representative one in all kinds of nonlinear systems. The block-oriented system method is applied to model for a weak-nonlinear system, while the inputs are sine waves and step signals. The modeling result makes it clear that in certain input range, the weak-nonlinear system can be described by a series model composed of linear dynamic subsystem and static nonlinear element. That is called a separated model of the nonlinear system. Then it is convenient to construct a nonlinear simulation circuit and experiment with it, and the circuit can be a substitution of the nonlinear dynamic high-pressure measurement system. At last, the conclusion is validated by experiments.