Time-Delay Systems

It is well known that, together with the increasing expectations of system dynamic performances, the delay information in practical systems or processes should not be neglected in the modelling procedure. Time delay is a very common phenomenon in the engineering world. In fact, many industrial processes include after effect phenomena in their inner dynamics. And actuators, sensors, and field networks that are involved in feedback loops usually introduce unavoidable delays. Time delays in dynamical systems arise as an inevitable consequence of finite speeds of information transmission. Realistic models increasingly demand the inclusion of delays in order to properly understand, analyse, design, and control real-life systems. Time delay is very often encountered in various technical systems, such as electric, pneumatic and hydraulic networks, chemical processes, long transmission lines, robotics, etc. So, the problem of controllability, observability, robustness, optimisation, adaptive control, pole placement and particularly stability and robustness stabilisation for this class of systems, has been one of the main interests for many scientists and researchers during the last five decades. Time-Delay Systems is concerned with the stability analysis and control problems of time-delay systems; a research field with at least six-decade long history that has been very active especially in the past two decades.