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

Defence Science Journal

S. Subha Rani¹  S. Sibi¹  P.P. Mohanlal² 

[1] PSG College of Technology, Coimbatore;Yikram Sarabhai Space Centre, Thiruvananthapuram

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;   

DOI  :  

学科分类：社会科学、人文和艺术（综合）

来源: Defence Scientific Information & Documentation Centre

【 摘 要 】

Control forces are required for steering alaunch vehicle to guide it to follow an optimal trajectory. Launchvehicle control involves two control loops, the inner loop deals withshort-period dynamics, stability and the outer loop, known as theguidance loop, optimises the trajectory. The general nonlinear plantmodel is first approximated as a linear time-varying plant over anominal trajectory and then segmented as linear, time-invariant plantmodels at different time intervals. A major part of the plant model isthe control power plant, which for a secondary injection thrust vectorcontrol system used for the solid booster stage of a launch vehicle isnonlinear due to various reasons. The controllers designed for differenttime regimes assume the control power plant as linear and are adaptedsmoothly by a technique called gain scheduling to cope with the plantmodel changes wrt time. In this paper, a fuzzy logic-basedpre-compensator is developed to linearise the control power plant sothat the controller design becomes valid. Simulation results arepresented to validate the design and a novel preprocessing technique isdeveloped to reduce the size of the fuzzy inference system.

【 授权许可】

Unknown