Analyse of robustness of the system and the design of the robust controller of the system focused in the research have been largely improved in the past 30 years,then the modern robust control comes into being.There are lots of the factors of delay which do not only have bad effect of performance of system,but also result in the instability of systems.So the theory of researching the state of system and controlling of the system is very important in theoretic study and application.On the other hand,it is very hard,what is worse,impossible to describe exactly the characters of system operating in the varying environment by time.There are some uncertainty which block the development of the researching and application of control system.The design and realization of system in the real world is desired to remain stability of systems which contain the time-delay dependant system,the uncertain system and the uncertain system with the time-delay are discussed by using the linear matrix inequality(LMI,for short).The models of them are extended to the one with double time-delay parameter.For more,the uncertain system with double time-delay is also researched.In fact,the systems which contain time-delay,uncertainty and uncertain mixed delay-time usually have worse stability and performance than that without time-delay and uncertainties,thereby should be paid attention to for studying the controller of system.In this note,those systems are investigated in ways of both state feedback and output feedback,and especially the static output feedback system is extend to dynamic output feedback.In order to get the less conservation,two measures have been taken as the following:Firstly,Lyapunov functional used in many research is improved by adding new functional terms and enlarging the state of system to characterize the system more precise.Secondly the derivative of the Lyapunov functional is dealt with to reduce the lost of system to lowest extent possible and keep more information of system. |