whereTistheyar
te
sio
RtistherealtimescrollradiusMtisthe
resista
tmome
toftheACservomotorMfistheviscousfrictio
almome
t
ωtisthea
gularvelocityofthescrollJtistherotati
gi
ertiaofthescroll
a
dtheyar
rolla
dM0isthedryfrictio
almome
t
Asshow
i
Eq1thescrollradiustheresista
tmome
tthea
gular
velocityoftheu
wi
dera
dtherotati
gi
ertiaofthescrollareallfu
ctio
sof
timea
dthesystemisthusacomplexmultivariabletimevaryi
gsystem
Propersimplificatio
ofthetorqueequilibriumequatio
iscarriedoutwith
classicalco
troltheorybasedo
thefollowi
grules
1Thedryfrictio
almome
ta
dtheviscousfrictio
almome
tareverylittle
a
dmaybeig
ored
2Thei
flue
ceofJtωto
thete
sio
forcemaybeig
oredsi
cethe
i
sta
ta
eousi
ertiacha
gesveryslightly
3Thescrollradiusisrealtimemeasureda
dfedbackbytheradiusfollowi
g
device
Eq1isthe
simplifiedas
TRtMtJtωt2
Thereforethevariatio
sofscrolldiametera
dscrolla
gularvelocityarethe
mai
i
flue
ci
gfactorsoftheyar
te
sio
3Compe
satio
oftheRadiusoftheScroll
Theradiuscha
geofthescrollcausesthecha
geofthescrollmome
tie
thecha
geoftheTRti
Eq2O
ee
doftheradiusfollowi
garmtouches
thescrolla
dtheothere
disco
ectedtotherotarypote
tiometerviagear
mag
ifyi
gstructurethustra
sformi
gacha
gei
thespi
dleradiustoa
cha
geofvoltageasshow
i
Fig2
fr