On the computation of flat outputs for nonlinear control systems

A simple procedure for the systematic computation of flat outputs for nonlinear control systems is presented. After symbolic linearization of the system equations, a so-called tangent flat output is determined. For this purpose, a new algorithm which is based on the calculation of nullspaces and generalized inverses is given. If some integrability conditions are satisfied, the flat output of the nonlinear system can be determined by integration. The procedure is illustrated in detail by computational examples.