On-Line Estimation of Time Delay and Continuous-Time Process Parameters

A simple technique is presented for on-line estimation of constant or slowly-varying continuous-time process parameters and time delay. A major advantage of the algorithm lies in its ability to track time-delay variations over a practically unlimited range. The technique is based on approximation of time delay in the frequency domain by a rational transfer function, construction of the derivatives of process input and output using multiple fil1ters, and estimation using a model nonlinear in the desired parameters. In spite of this inherent nonlinearity with respect to the sought parameters, the estimation scheme has a unique solution, in general.