Adaptive and optimal control of time-delay systems

• Main Author: Garland, Bernard
• Published: University of Bath 1978
• Subjects: 621.3
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.456244

Sensitivity Analysis for a time-delay system is extended to Adaptive Control of systems with parametric and temporal mismatch. An adaptive control system based on the Smith predictor is investigated analytically and by hybrid and digital simulation. Systematic procedures for choice of adaptive loop gains is given, and the close relationship between linearity of sensitivity coefficients and constancy of adaptive loop gains is discussed in depth. The importance of non-commutativity of time varying elements in an adaptive control scheme is considered. Delay-free optimal control methods are extended to the delay case both for LQP and parametric optimisation. Iso-cost functionals are investigated with respect to temporal and parametric mismatch. Sub-optimality of certain optimal schemes is exposed, and it is shown that in the cases considered optimal performance may be improved by deliberate mismatch of plant and model.