出版社：Defence Scientific Information & Documentation Centre
摘要：Control forces are required for steering a launch vehicle to guide it to follow an optimal trajectory. Launch vehicle control involves two control loops, the inner loop deals with short-period dynamics, stability and the outer loop, known as the guidance loop, optimises the trajectory. The general nonlinear plant model is first approximated as a linear time-varying plant over a nominal trajectory and then segmented as linear, time-invariant plant models at different time intervals. A major part of the plant model is the control power plant, which for a secondary injection thrust vector control system used for the solid booster stage of a launch vehicle is nonlinear due to various reasons. The controllers designed for different time regimes assume the control power plant as linear and are adapted smoothly by a technique called gain scheduling to cope with the plant model changes wrt time. In this paper, a fuzzy logic-based pre-compensator is developed to linearise the control power plant so that the controller design becomes valid. Simulation results are presented to validate the design and a novel preprocessing technique is developed to reduce the size of the fuzzy inference system.
关键词：Secondary injection thrust vector control system, launch vehicle, fuuy logic. nonlinear plant model, fuzzy inference system, control power plant, control loop, fuzzy inference system. pre-compcnsalor
