Nonlinear system identification—Application for industrial hydro-static drive-line

• We apply a nonlinear system identification procedure to industrial scale hydralic driveline plant.
• We investigate the level of nonlinearities in different parts of the system and under different operating conditions.
• The frequency based approach can detect early the need for nonlinear modeling.
• Early evaluation of the further complexity and costs can be made.

The goal of the paper is to describe the added value and complexities of nonlinear system identification applied to a large scale industrial test setup. The additional important insights provided by the frequency domain nonlinear approach are significant and for such systems the nonlinear system identification is important, for example to estimate the noise and non-linearities levels, which can indicate mechanical and configuration issues. It is not the goal to provide a final full-scale model, but to explore what is the applicability of the nonlinear system identification theories for a complex multi-physical non-academic test-case.