Requirements for an Aerospace Actuation System derived from the Control Design Point of View
Timo Wekerle1; Alexandro Brito2; Luís Gonzaga Trabasso3
1 Instituto Tecnológico de Aeronáutica and Instituto de Aeronáutica e Espaço; 2 Universidade Federal de Santa Catarina; 3 Instituto Tecnológico de Aeronáutica
doi:10.20906/CPS/COB-2015-1373
Resumo
This paper presents the assessment of performance and system requirements for a thrust vector control system (TVC). The TVC consists of a movable nozzle with a divergent and a flexible laminated bearing that is deflected by electrohydraulic actuators. The angular displacement of the nozzle results in thrust redirection, responsible for the attitude control of a launch vehicle. The main system requirements of a TVC system for launch vehicles will be analyzed and discussed. Furthermore, some ambiguous requirements found in the literature for the performance of the actuation system are pointed out. Finally, an integrated approach for obtaining TVC system requirements will be introduced, which leads to a balance between the control engineering side and the hardware side. This interaction between the different technical areas might anticipate problems and avoid requirements that are not able to be complied. The launch vehicle is represented by a rigid body model with six degrees of freedom and subsequently the necessary hypotheses are introduced in order to simplify and to linearize such model. Hence, a controller for the actuators is proposed in this paper. The approach is divided into six steps including disturbance analysis and the introduction of physical limitations like saturation in angle and velocity. In order to verify this approach, a simulation with data from the Brazilian Satellite Launcher (VLS-1) is used.
Palavras-chave: Thrust Vector Control; Launch Vehicle; Requirements; Attitude Control