Details of Grant 

EPSRC Reference:	EP/C005953/1
Title:	Control and Stability Analysis of Time-Delay Systems
Principal Investigator:	Zhong, Professor Q
Other Investigators:
Researcher Co-Investigators:
Project Partners:
Department:	Electrical Engineering and Electronics
Organisation:	University of Liverpool
Scheme:	First Grant Scheme Pre-FEC
Starts:	01 September 2005	Ends:	30 September 2008	Value (£):	126,413
EPSRC Research Topic Classifications:	Control Engineering
EPSRC Industrial Sector Classifications:	Energy Transport Systems and Vehicles
Related Grants:
Panel History:
Summary on Grant Application Form
Systems with delays frequently appear in engineering. One reason is that real processes are full of time delays. Another reason is that time-delay systems are often used to model a large class of engineering systems, where transmission of information or material is involved. Typical examples of time-delay systems are communication networks, chemical processes, tele-operation systems and so on. Normally, the presence of delays (especially, large delays) makes systems less productive, less optimal and less stable. From the control point of view, it makes system analysis and controller design much more complicated. The first effective control scheme for (stable) time-delay systems is the celebrated Smith predictor, which was proposed in the late 1950s. It was then extended to control unstable time-delay systems in the late 1970s. Since 1980s, the robust control of time-delay systems has attracted a lot of attention. Various robust control problems have been solved, but mostly for systems with a single delay. A numerical problem in the conventional predictor was identified in 2003 and a new type of predictor, called the unified Smith predictor (USP), was proposed. Some further work needs to be done with respect to the USP. Another active topic in time-delay systems is the stability analysis. The major objectives of the proposed research is: (i) to further investigate robust control problems for time-delay systems, in particular, for those with multiple delays and to do comparative studies for different situations, e.g. comparing the conventional predictor and the USP when both can be used; (ii) to investigate problems related to the implementation of distributed delay in control laws, such as to find the minimum number of the implementation steps to guarantee the stability of the system and to find rational implementations in order to save efforts in implementation; (iii) to develop advanced control techniques for chemical process control; and (iv) to develop stability criteria for time-delay systems using the results obtained in robust control of time-delay systems.The proposed research may involve many applications. Those already identified include: repetitive control in power converters to reduce the total harmonic distortion; damping control of inter-area oscillations in large power systems; fixed-lag smoothing to recover information; vehicle path tracking using preview control; control of underwater vehicles; combustion systems; control of tyre extruders; and control-over-network etc. In addition to industrial users, other academic researchers will also benefit from the proposed research. The output in the form of high quality journal papers and conference presentations will benefit the international academic community and will enhance the standing of UK science.
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Organisation Website:	http://www.liv.ac.uk