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.


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    Title :

    Secondary Injection Thrust Vector Control Power Plant Linearisation using Fuzzy Logic for a Launch Vehicle


    Contributors:
    Rani, S. Subha (author) / Sibi, S. (author) / Mohanlal, P.P. (author)

    Publication date :

    2002-10-01


    Remarks:

    doi:10.14429/dsj.52.2198
    Defence Science Journal; Vol 52 No 4: Aerospace Quality and Reliability; 409-416 ; 0976-464X ; 0011-748X



    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English


    Classification :

    DDC:    629