The research field Nonlinear Systems is concerned with the development of methods, and the practical implementation of observer and control strategies for systems with significant nonlinear behavior. The basis for the considered model-based design approach are suitable mathematical models. These models are, as far as possible, derived based on the main principles of physics, utilizing the system’s geometrical and construction parameters. This allows for a simple parameterization of the models, the analysis of the influence of model parameters on the characteristics of the closed-loop system and a mechatronic design of the overall system. The model structure is also the basis for the choice of a proper control or observer strategy, such that a wide field of nonlinear design methods are applied. Similar to other fields of research, a focus lies on the practical implementation of the developed controller and observer strategies in a real (industrial) application. Thus, questions concerning the efficient, real-time capable implementation on real-time hardware (DSP, FPGA) are also an important topic.