Publications

Fast Step-Response Evaluation of Linear Continuous-Time Systems with Time Delay in the Feedback Loop

Yves Piguet and Philippe Mullhaupt. 17th IFAC World Congress, Seoul, South Korea, July 2008.

Abstract

The simulation of step, impulse and ramp responses of linear continuous-time time- invariant single-input single-output systems with a pure time delay in the feedback loop is tackled. Contrary to systems without time delay where a conversion from Laplace transform to z transform with a zero-order hold allows for an exact response, delay in the feedback loop requires either an unbounded number of states or approximations. This paper proposes an approximation which fulŞlls a set of criteria, including exactness of the response over a speciŞed multiple of the delay and the conservation of the stability or lack of stability. The approach is illustrated with examples.