A predictive multivariable helicopter robust design

The characteristic decomposition methodology and its use for the multivariable characteristic GPC (CGPC) are reviewed. The approach is illustrated via a helicopter application. The characteristic decomposition results and the simulations obtained by the MIMO CGPC are given. These simulations show that the initial feedback configuration has to be slightly modified to ensure the required performance/robustness. With good eigenstructure approximations, the CGPC design offers important advantages: (i) by means of eigen projection, it decouples and simplifies the prediction equations; (ii) by the ease of use of independent prediction parameters for each subsystem, it makes it possible to shape the individual subsystems behavior and, hence, the behavior of the overall system according to the necessary and sufficient generalized Nyquist condition; and (iii) the appropriate use of a matrix polynomial filter makes it possible to achieve the desired robustness