Improvement of system performance by the use of time-delay elements

The paper explores the possibility of performance improvement by the use of added delay elements. The counterintuitive phenomenon of ‘improvement by mismatch’ has been noted by several authors in the context of predictor control. This phenomenon is illustrated using a second-order example, and, in the light of this, it is demonstrated how it also may be improved by the use of delay elements. A third-order example of delay-free system improvement is described. A technique for producing good first-order estimates of design parameters is presented