Abstract
This communication presents a comparative analysis of tuning techniques for satellite launch vehicle attitude controllers. The investigated tuning techniques consist in the minimization of specific performance indexes, namely the Integral Absolute Error (IAE) index, the Integral of Time Multiplied Absolute Error (ITAE) index, the Integral Squared Error (ISE) index, and the Integral of Time Multiplied Squared Error (ITSE) index, being hence, termed optimal. By defining adequate figures of merit, relevant for evaluating the overall performance of satellite launch vehicles, and also taking into account requirements related to the physical limitations of the latter, the performance of attitude controllers tuned by the investigated techniques is compared to the one tuned by the methodology currently employed in the Brazilian Satellite Launch Vehicle (VLS), namely, the Linear Quadratic (LQ) methodology. Through simulation results, it is demonstrated that, despite sparse benefits produced by the alternative tuning techniques, in particular ITAE and ISE, the LQ methodology remains globally superior.
Highlights
The Brazilian Satellite Launch Vehicle (VLS) is a launcher endowed with 4 independent propulsive stages, approximately 50 tons of weight and 19 meters height, whose main purpose is to insert payloads in circular orbits, which can range from 250 km to 1000 km of altitude (Ramos et al 2003)
From the rising time point of view, the Integral Absolute Error (IAE), Integral of Time Multiplied Absolute Error (ITAE) and Integral of Time Multiplied Squared Error (ITSE) indexes resulted in faster responses which, excessively approached the limit rising time established in preceding Sections
As a final remark we must highlight that, due to the various simplifications considered throughout this communication, the results presented hitherto, concerning the optimal choice of tuning techniques for satellite launch vehicle attitude controllers, should be considered as preliminary, and mainly valid for initial stages of the control system design process
Summary
The Brazilian Satellite Launch Vehicle (VLS) is a launcher endowed with 4 independent propulsive stages, approximately 50 tons of weight and 19 meters height, whose main purpose is to insert payloads (up to 350 kg) in circular orbits, which can range from 250 km to 1000 km of altitude (Ramos et al 2003). The performance of the temporal response isRRq=uit0e.4dependent on the choice of Q and R matr(i2(c20e0s), Aws ihnitcrohd,ucfeodrinbpereicnegdinggeSnecetriaonllsy, theemmpaiinripcuarlployse pofetrhfiosrcmomemd,uniiscatigorneiasttloyprdeseepnte(nadndenant aloyzne) tahlteerndateivseigtunneinr’gs techniques for the computation of the attitude controller feedback gains, which eliminate the empiricism associated to the choice of thee xQpaenrdieRnAmcesatr(iiBcnetrsriiotnodtuahencedLdQLmeiniettehpoFrdeiolclhoegodyi.2n0g05S)e.ctions, the main purpose of this communication is to These alternative techniques, presented in sequence, are based on the minimization of different performance indexes (or optimparlietysecnrittAe(riacanc),odarnaddninaargleytzrtoaen)sRlaaatletmde,roanssawteiivltlebaetlu.shn(oi2wn0ng0, i3tne)dc, ihfffneorireqnutthedesynfBaomraictzhbieleihacanovimoVrpsLfuoStrattahiteotcintounodcfeertnhceeodnasytsrttioetlmulde. According to Silva Feintalalyl,.th(e2l0as1t4p)e,rfohromwanecveeirn,defxoirnvtehsetigsapteedciinfithcisccaosmemoufniscaattieolnliitsethleaIuTnSEchindveexh, wichliechs,haas brieseinnogrigtiinmalely bdeesliognweda to increase the selectivity of the ISE index (Chen 1993) It is calculated by the following cost function (Eq 27), given limit value (adopted in this communicatiobn as 0.5 s) can compromise the physical integrity of the vehicle due to the excitation ofJJEi^t5sfb=endKUingtttmt2(otdt)edsdd.d. For the same reason, the settling (27)(27) time and the maximum overshoot are desired to be minimal. In order to ensure that the controllers tuned by each of the investigated techniques
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
