Deadtime Approximations with Adaptive Deadtime Compensation

Simple polynomial approximations of the Padé type are considered for deadtime estimation with single-loop adaptive control. An LQG regulator is used with combined parameter identification via a Sequential Gauss-Newton (SGN) method. These include provisions for unknown constant load inputs and random noise effects. An equation error approach is used based upon the deadtime-plus-first order (DT+FOE) model form. However, for the error partial with respect to deadtime, two forms are given based upon a simple Padé approximation for part of the deadtime. One form of the partial relates to the equation error and the other is a hybrid form relative to an output+equation error formulation. Simulation tests of the adaptive control procedures were made for combined parameter changes, including the deadtime. These results are discussed relative to conditions for satisfactory convergence.