Estimation of Subsample Delays for Computer Control Systems

A new method is described for estimating input time delays in linear plants. The method is based on discrete-time domain identification of such delays, and provides direct estimates in real-time. For computer control systems, the delay is allowed to be a noninteger multiple of the sampling period. Both input (actuator) delays and subsample (computational) delays can be estimated. The identification algorithm is based on a recursive Gaussian-Newton prediction error search technique. A simulation study indicating fast convergence for a second order delayed system is included.