Engineering topics
Publications and source records attributed to Mookerjee, Purusottam.
Simulations indicate superiority of dual controller over "cautious" controller. Report discusses principles of design of actively adaptive dual controllers. Focus is upon derivation of control laws for dual controller enhancing identification of parameters of mathematical model of multiple-input/multiple-output system, while controlling it at same time. Tasks of identification and control impose competing requirements.
The design of an actively adaptive dual controller based on an approximation of the stochastic dynamic programming equation for a multi-step horizon is presented. A dual controller that can enhance identification of the system while controlling it at the same time is derived for multi-dimensional problems. This dual controller uses sensitivity functions of the expected future cost with respect to the parameter uncertainties. A passively adaptive cautious controller and the actively adaptive dual controller are examined. In many instances, the cautious controller is seen to turn off while the latter avoids the turn-off of the control and the slow convergence of the parameter estimates, characteristic of the cautious controller. The algorithms have been applied to a multi-variable static model which represents a simplified linear version of the relationship between the vibration output and the higher harmonic control input for a helicopter. Monte Carlo comparisons based on parametric and nonparametric statistical analysis indicate the superiority of the dual controller over the baseline controller.