Symbolic computation for dynamic sliding mode controller design

In general, nonlinear controller design will involve three stages; symbolic computation to produce a controller, numerical simulation of the closed-loop system and graphical display of the simulation results. The integration of these three phases can be seen in the work of Blankenship et al. (1995) where several tool boxes have been developed. In principle all three stages can be performed in any symbolic package such as MACSYMA, Mathematica, MAPLE, or REDUCE. The applications experience of the authors indicates that numerical integrators in those packages are far from enough. Thus it is necessary to interface with other languages or packages such as MATLAB or the Fortran NAG Library in order to exploit their numerical simulation functions and routines. The paper describes the preliminary development of a nonlinear sliding mode controller design package