提高采样控制系统带宽的方法研究

Vol.30,No.4Opto-ElectronicEngineeringAug,200312——V556AmethodforimprovingthebandwidthofasamplingcontrolsystemFENGXing-qiang1,YANGWen-shu21No.95948UnitsofPeople'sLiberationArmy,Lanzhou732750,China2InstituteofOpticsandElectronics,ChineseAcademyofSciences,Chengdu610209,China)Abstract:Mainfactorsaffectingbandwidthofacontrolsystemareresonancefrequencyofmechanicalstructure,accelerationcapacityandsamplingfrequencyofthesystem.Theanalysisofthesefactorsiscarriedout.Twomethods─virtualsamplingmethodandmulti-frequencysamplingmethod,usedforexpandingsystembandwidth,aregiven.Adiscussionforvirtualsamplingmethodiscarriedout.Theexperimentalresultsshowthatwheninterpolationnumberisnotbiggerthan4theinterpolationaccuracyofthevirtualsamplercanmeetwiththedemandofapplicationandthesystembandwidthcanbeexpandedforabout3times.Keywords:TrackingcontrolsystemsSamplingfrequencySystembandwidth123PWMCCDCCD,7.5Hz1Hz2002121120030120197221LJKrr=w1KrJLKr50Hz0dB[1])]1/(lg[20+≤PpMMP2Pwrmaxq&&Tmin[2]maxmin2q&&IT=3Imaxoqw&&≈4ƒswo[3]so2fwg=5ƒoLƒsiTTMMf∑+⋅+⋅≤)2(11ð21oL6T=1/ƒsiT∑2TTi≤MMƒoLƒcLƒcL≈(1.1~1.4)ƒoL7104Hz40Hz2211aT/n(n)D(Z)T/n1b1cD(Z)TD(Z)D¢(Z)T/nabcnFS(FictitiousSampler)nT/n1(b)(c)[4]T/nT/nnHermite[34]HermiteNewton[5]2Fig.1Schematicdiagramforaddedsampler(a)Samplerisinfrontofthecontroller(b)Samplerisinbackwardofthecontroller(c)Samplerisinfeedbackbranch(c)H(s)c(t)T/nr(t)+TG(s)D(s)D(s)c(t)T/nG(s)r(t)+T(b)D(s)c(t)T/nG(s)r(t)+T(a)Fig.2Sectionsforquadraticpolynomialinterpolation233yk2yk1ykyk+mT/n……yk+(n-1)T/nnn24816……24816……)(31221/nmyAyAyAyknmknmknmnmTk++=′--+8Anm1Anm2Anm3[6]n=4A4mj(m4j=1,2,3)1nR(t)=Asin(wt)yk+mT/n)(nmdΔ333)(6/))(2(nfmnmnmAsnm++≤Δwd9)(nmdΔƒsn)(nmdΔmm=n1)]/1(3)][/1(2)][/1(1)[6/(3s3)(nnnfAnm---≤Δwd10n)(nmdΔ)16(max)8(max)4(max)2(maxddddΔΔΔΔ119Δqmaxsin(wt)Δqmax7.5Hzw5rad/s4)4(mdΔmaxmax)4()6/1(1689.0qqdΔ≈Δ≤Δm)2(mdΔ)4(mdΔmax)6/1(qΔ430Hz15rad/sn≤430Hz[1].[M].1984.[2].[M].1980.[3].[M].1985.[4].[M].1989.[5].[M].1982.[6].[M].1987.n=A4mjmj=Table1A4mjvalue(m4,j=1,2,3)whenn=4mA4m1A4m2A4m310.12625-0.56251.4062520.375-1.251.87530.65625-2.06652.40625Fig.3Sketchforparabolicinterpolationyk2yk1yk0yttk2tk1tk+1tk