Fuzzy Sliding Mode Control For A Class Of Delay Systems With Uncertainties

Because of transmission time-delay of signal and substance, and the change of work circumstance, time-delay with uncertainty broadly exists in the field of control, this is one of the biggest puzzle in control field. Variable structure control is brought in 50's. The sliding mode movement of variable structure system holds the invariance for the change of system parameters, outside disturbance. In the course of the research, there are two mainly puzzles: chattering and the restrict of matched condition. Many scholars have researched these puzzles. In this paper, some researches have been done on the base of reading many references about time-delay and sliding mode control system:Firstly, the problem of designing an adaptive sliding mode controller for a class of input-delay systems with mismatched uncertainties based on a transformation that converts the original system into a delay-free form is investigated. Based on Lyapunov stability theorem a sufficient condition with delay-dependent guaranteeing the asymptotically stable in the sliding mode is derived. This condition breaks through the restriction of matched condition, and extends the application of sliding mode control. It can stabilify the system with time-delay from 0 to 5. Compared with references before, it has the small conservation.Secondly, aiming to weaken the chattering, intelligent fuzzy control is brought in. According to the idea of boundary, the system is controlled separately with fuzzy control and sliding control when the sliding mode in the boundary and out of the boundary. The results of simulation show that this method can weaken the chattering and stabilities the system.Finally, this control measure is brought in the temperature control of reactor. The simulation results show that this measure can control the temperature of reactor effectively.