Electrohydraulic System Response - Nonlinear vs Linear

The results from an investigation of some of the effects of using a linearized model for prediction of the behavior of a nonlinear system are presented. The system studied is a velocity system using an electrohydraulic servoactuator to drive an inertial load. Both nonlinear and linearized system models are defined.

The result of defining optimal feedback values for an integral quadratic performance index is shown along with the effect of choice of nominal operating point on the linearized system transient response. Finally, linear and nonlinear transient responses are compared for a range of step amplitudes.