Exact Fuzzy Modeling and Optimal control of a Launch Vehicle in the atmospheric phase

This paper presents a novel method of Exact Fuzzy Modeling and Optimal control of a Launch Vehicle in the atmospheric phase. Time varying plant is considered with control power plant nonlinearity. Plant modeling, controller design and analysis are carried out for Rigid Body with Actuator dynamics. The results are compared with a classical design. Conventionally, the TSK fuzzy modeling blends local linear models to represent a nonlinear system, which in general does not exactly represent the nonlinear system under consideration. Here, instead of local linear models, a set of ´boundary linear models´ and associated membership-functions are so chosen that the fuzzy blending of these models result in an exact representation of the overall nonlinear time varying system. Optimal control laws are designed for each of these fuzzy subsystems, and overall control is again the fuzzy blending of these individual control laws. This procedure results in an exact optimal control solution for the Launch Vehicle control in the atmospheric phase.