Symbolic computation environment for nonlinear L2 control. application examples

In this work a computer based environment for symbolic calculation applied to nonlinear L2 control is described. A very practical design and analysis methodology for nonlinear H∞ control is presented. Starting from a model of the plant in affine form, and a state feedback controller (or state estimated feedback controller), a design procedure is established using nonlinear L2 control theory. Functions hz(x), kuz(x) and parameter γ are used as design parameters. Due to the fact that exhaustive symbolic computation is necessary in nonlinear L2 control, the Maple program has been used. The application is also based on Matlab and Simulink in order to implement functions from Control Toolboxes and simulation facilities. An additional advantage of the control theory used and the design procedure implemented in this work is that it can be applied to scalar and multivariable nonlinear systems. The design methodology and the software environment are tested by means of the simulations studies carried out with SISO, MISO, SIMO and MIMO systems.