a Minor extensi where the transfer function G1 is SPR The errore=y- ym can then be witten as MRAS with aug mented error e=G(8-0 )uc=(G1G2( 0-8 )uc Model G1(G2(0-6)uc+(0-")G2uc-(0-6)G2uo Introduce Process -(@-引° where n is the error augmentation defi ned by G1(6-6°)G Use adaptation law dt Compare Str and Mras W hat You should Know MRAS d e e the ideas Ypf How to make abstractions pf=-Gf(p)grade(t) The( E=GSPR(y-ym)+n=G SpRe +n Nations df g ain phase and passivity Direct str PR and sPr y(t)=pf(t-do)8 The key resuts The small gain theorem e(t)=v(t)-=y(t)-9(t-do)(t-1) The passivity theorem (t)=6(t-1)+P(t)9f(t-do)e(t) The arde criterion Abilit impute g e(t=yt-y(t) Determne passway =y(t)-ym(t)+ym()-y(t Apply to adaptive cortrd e(t)+、(t) Similarities between MRAS STIRA Minor Extension Factor G = G1G2 where the transfer function G1 is SPR. The error e = y ym can then be written as e = G( 0 )uc = (G1G2)( 0 )uc = G1G2( 0 )uc + ( 0 )G2uc ( 0 )G2uc Introduce " = e + where is the error augmentation dened by = G1( 0 )G2uc G( 0 )uc = G1(G2uc) Guc Use adaptation law d dt = G2uc MRAS with Augmented Error – + Model Process y – e Σ Σ θ Σ θ + η ε uc ym k0G kG − γ s G2 G1 u c Π Π Π Compare STR and MRAS MRAS d dt = 'f " 'T f = Gf (p)grad"(t) " = GSPR(y ym) + = GSPRe + Direct STR y(t) = ' T f (t d0) "(t) = y(t) =^ y(t) 'T f (t d0) ^ (t 1) ^ (t) = ^ (t 1) + P (t)' T f (t d0) "(t) Residual "(t) = y(t) y^(t) = y(t) ym(t) + ym(t) y^(t) = e(t) + (t) What You Should Know! The ideas { How to make abstractions The concepts { Notions of gain phase and passivity { PR and SPR The key results { The small gain theorem { The passivity theorem { The circle criterion Abilities { Compute gain { Determine passivity { Apply to adaptive control Similarities between MRAS STR c K. J. Åström and B. Wittenmark 6