A Computer Aided Software for Nonlinear Digital Control

The aim of this paper is to provide a basic software tool involved in the design and the computation of nonlinear digital control schemes. The complete software SimNLSys will include different modules associated with each control scheme, aimed with respective objectives such as stabilization, damping, output matching or optimality, to quote a few. The software module presented here also encompasses the goal of computing solutions to nonlinear ODE's describing input-affine dynamics. The underlying methodologies propose challenging nonlinear sampled-data control strategies described in terms of Lie series expansions and computable through formal series calculus. The goal is to reach a friendly graphical user interface, to promote the practical efficiency of such strategies. For this, SymNLSys is built using the symbolic Matlab toolbox and the resulting mathematical control law expressions can be implemented directly on experimental plants. The paper describes the used differential geometric methods and discusses the implementation and limitations of the symbolic and numerical algorithms. Also some results obtained via this software are provided.