Implementation of multi-rate model reference adaptive control for continuous systems via bilinear transformation based on block-pulse functions

Abstract

The discretization or approximation techniques for continuous systems using the well-known delta operator and the bilinear transformation based on block-pulse functions or the trapezoidal rule are discussed. Then implementation techniques of multi-rate indirect model reference adaptive control for continuous systems purely using digital computers arc described. The scheme is composed of three components: a general recursive least-squares type parameter estimator, a continuous plant model and a controller designed in continuous-time domain. To reduce the computational burden, the algorithm is implemented in a multi-rate manner with a small sampling interval of the system signals and a relatively large parameter estimation interval. Comparisons of the discretization methods for the adaptive system using block-pulse functions, the trapezoidal integrating rule and the well-known delta operator are discussed through simulation study. It is shown that the block-pulse function method is the most effective one.