Upload
hieu-dinh
View
218
Download
0
Embed Size (px)
Citation preview
7/30/2019 BI TP LP A Qun
1/15
BI TP LP: IU KHIN S 8:TN TIThit k xp x lin tc khu iu chnh tc ng c DC Servo Harmonic RHS17-3006.
MC TIUGip sinh vin bit cch thc hin k thut iu khin s vi mt h thng ctng hp trn min thi gian lin tc.NI DUNGXy dng chng trnh m phng trn Matlab Simulink kim nghim cc ktqu t c trn min thi gian lin tc v trn min thi gian gin on.NHIM V CA SV- M t i tng iu khin.- Kho st ng hc ca i tng trn min thi gian lin tc.- Kho st nh hng ca chu k trch mu T n tnh n nh ca h thng.
- Tiu chun thit k v kt qu m phng trn min thi gian lin tc- Cc phng php thit k xp x lin tc v kt qu m phng trn min thi giangin on.- So snh cht lng iu khin v kt lun- Kim chng trn m hnh thc nghim (nu c)
1
7/30/2019 BI TP LP A Qun
2/15
Chng 1. Tng quan v ng c DC Servo RHS 17-3006
1. Gii thiu v ng c DC Servo RHS 17-3006
a, Gii thiu v DC Servo
ng c Servo l nhng h hi tip vng h - ta cp in ng c quay.
Vic thit lp mt h thng iu khin xc nh nhng g ngn cn chuyn ng
quay ca ng c hoc lm ng c khng quay cng khng d dng.
Mt khc Servo c thit k cho nhng h thng hi tip vng kn. Tn hiu
ra ca ng c c ni vi mt mch iu khin. Khi ng c quay, vn tc v v
tr s c hi tip v mch iu khin ny. Nu c bt k l do no ngn cn
chuyn ng quay ca ng c, c cu hi tip s nhn thy tn hiu ra cha t
c im chnh xc.ng c Servo c nhiu kiu dng v kch thc, c s dng trong nhiu
my khc nhau. ng c Servo c s dng ph bin nh l cc c cu chp hnh
c iu khin bng vi x l, va nh gn, va tit kim nng lng li r tin.
ng c Servo c moment xon cao so vi kch thc ca n, c th cho v tr gc
chnh xc bng cc cung cp xung theo phng thc iu bin rng xung
(PWM), rng ca xung s quyt nh v tr gc ca trc ng c.b, Cu to ca ng c Servo
Hnh 1.1. Hnh dng ng c Servo Hnh 1.2. Cu to ng c Servo
2
7/30/2019 BI TP LP A Qun
3/15
* Ch thch:
1 - ng c chnh
2 - Board mch iu khin tn hiu hi tip
3 - Dy dng ngun (Red)
4 - Dy tn hiu vo ( Yellow or White )
5 - Dy m ngun ( Black )
6 - Volt k
7 - u ra: Trc/Bnh rng
8 - C cu chp hnh
9 - V ng c
10 - Chp iu khin chnh
c, Nguyn l hot ng.
ng c servo c thit k quay c gii hn m khng phi quay lin tc
nh ng c DC hay ng c bc. ng c v vn k ni vi mch iu khin to
thnh mch hi tip vng kn. C mch iu khin v ng c iu c cp ngun
DC (thng t 4,8 7,2V). quay ng c , tn hiu s c gi ti mch iukhin. Tn hiu ny khi ng ng c, thng qua chui bnh rng, ni vi vn k.
V tr ca trc vn k cho bit v tr trc ra ca Servo. Khi vn k t c v tr
mong mun, mch iu khin s tt ng c.
i tng iu khin y l ng c ng c RHS 17-3006 ca hng
Harmonic. ng c ny thuc dng RHS - series (Sizes 17) l dng ng c c
thit k nh gn, truyn ng chnh xc, moment ln v c gn sn encoder.2. Cc tham s c bn ca ng c RHS 17-3006
1. Kiu chy : Lin tc
2. Kch thch : Nam chm vnh cu
3. Cch in : lp F
4. in tr cch in : 100M
5. Nhit mi trng : -10 ~ +40oC
6. Nhit lu tr: -20 ~ +60 oC
7. m mi trng : 20 ~ 80 % ( khng ngng t )
8. rung : 2.5g (5 ~ 400HZ)
9. Shock : 30g (11ms)
10.Bi trn : Du nhn (SK - 2 )
3
7/30/2019 BI TP LP A Qun
4/15
11.u ra : Thn trc.
12.Kch thc : 250x250x12 mm.
Bng 1.1. Bng thng s ng c ng c RHS 17-3006
Thng s n v ng c RHS 17-3006Cng sut u ra (sau hp s) W 62in p nh mc V 75Dng in nh mc A 1.7Mmen nh mc TN In-lb 174
Nm 20Tc nh mc nN Rpm 30Mmen hm lin tc In-lb 195
Nm 22Dng nh A 3.5Mmen cc i u ra Tm In-lb 475
Nm 54Tc cc i Rpm 40Hng s mmen (KT) In-lb/A 170
Nm/A 19Hng s in B.E.M.F ( nh hngca tc n s phn ng )(Kb)
v/rpm 2
M men qun tnh (J) In-bl sec2 3.15
Kgm2 0.36Hng s thi gian c kh Ms 4.7 dc c tnh c In-lb/rpm 72
Nm/rpm 8.1H s momen nht ( Bf) In-lb/rpm 2.7
Nm/rpm 3.1*10-1
T s truyn 1:R 1:100Ti trng hng tm Lb 176
N 784
Ti trng hng trc Lb 176N 784Cng sut ng c W 100Tc nh mc ng c Rpm 3000in tr phn ng 4.8in cm phn ng mH 2.3Dng khi ng A 0.7Dng khng ti A 0.23
4
7/30/2019 BI TP LP A Qun
5/15
Chng 2. Thit k xp x lin tc khu iu chnh tc ng c
DC Servo RHS 17-3006
1. M hnh ton ca ng c DC Servo RHS 17-3006
a, Cc phng trnh ton hc ng c DC servo RHS 17-3006
+ Cc tham s c bn ca ng c:
1. in tr phn ng: RA = 4.8
2. in cm phn ng: LA = 2.3 mH
3. Hng s mmen: KT = 19 Nm/A
4. Hng s in: Kb = 2 V/rpm
5. H s momen nht: Bf = 3.1*10-1
6. M men qun tnh: J = 0.36
Ta c cc phng trnh m t i tng ng c DC Servo
1
( )
A
A A A A A
dc c
dc t A
A b
diu e i R L
dt
dM M
dt J
M K i
e K n
= +
=
= =
Chuyn sang min nh laplace:
1( )
A A A A A A
dc c
dc t A
A b
u e i R L i s
s M MJ
M K i
e K n
= + =
==
( )1
1( )
A A A
A A
dc c
dc t A
A b
i u eR L s
M MJs
M K i
e K n
= +
=
=
=
ThayA
A
A
LT
R= ta c h phng trnh sau:
5
7/30/2019 BI TP LP A Qun
6/15
( )1 /
1
1( )
A
A A A
A
dc c
dc t A
A b
Ri u e
T s
M MJs
M K i
e K n
= +
=
=
=
T h phng trnh trn ta xy dng c s cu trc ca ng c nh sau:
Hnh 2.1. Cu trc ng c DC servo
Thay cc thng s ca ng c vo ta c m hnh ng c DC servo trn
simulink sau:
Hnh 2.2. Cu trc ng c DC servo RHS 17-3006
Kt qu m phng trn Matlab Simulink ta c: c tnh qu tc v
dng ca ng c DC Servo RHS 17-3006
6
7/30/2019 BI TP LP A Qun
7/15
Hnh 2.3. c tnh dng phn ng ng c DC servo RHS 17-3006
Hnh 2.4. c tnh tc ng c DC servo RHS 17-3006
2. Thit k xp x lin tc khu iu chnh tc ng c
a, Cc phng php thit k xp x lin tc
Ta chn b iu khin c dng PI, lut iu khin c m t bi cng thc:
( )1
0
1( ) ( )
R
c
u t K e t e d T
= +
Trong :
KR: H s t l
Tc: Hng s thi gian chm sau
thit k trn min thi gian xp x lin tc ta xp x thnh phn I theo cc
phng php sau:
+ S dng phng php hnh ch nht: xp x thnh phn I
7
7/30/2019 BI TP LP A Qun
8/15
( ) 11
k
I i
iI
Tu k e
T
=
( )1
1
1
1k
I i
iI
Tu k e
T
=
( / )I C RT T K=
Tr v vi v v chuyn v i du ta c:
( ) ( ) 11I I iI
Tu k u k e
T + ( )
1 1( ) ( )I
TU z z U z z E z
T
= +
( )1 1( ) ( )
I
TU z z U z z E z
T
= +
( ) 1
1( ) 1I
U z T z
E z T z
=
( )
11
11RI
T zR z K
T z
= +
+ S dng phng php hnh thang:
( ) ( )11
1
2
k
I i i
iI
Tu k e e
T
=
+
( ) ( )1
1
1
11
2
k
I i i
iI
Tu k e e
T
=
+
( / )I C RT T K=
( ) ( ) ( )11
12
I I i i
I
Tu k u k e e
T + +
( ) ( ) ( )1112
k k
I
Tu k u k e eT
+ +
( ) ( )1 11
( ) ( ) ( )2I
TU z z U z E z z E z
T
= + +
( ) 1
1
1
( ) 2 1I
U z T z
E z T z
+ =
( )
11
1
1
2 1R
I
T zR z K
T z
+ = +
3. Tng hp b iu khin
a,Thit k b iu khin trn min thi gian lin tc
iu khin tc ng c DC Servo thng thng ta dng h thng hai
vng iu chnh:
+ Cu trc mch vng iu chnh dng in.
- Ta c hm truyn ca mch vng dng in:
8
7/30/2019 BI TP LP A Qun
9/15
s
. /( )
( . 1)( . 1)cl i u
i
u
K K RS s
T s T s=
+ +vi :Ts = Tdk+ Tv
- p dng tiu chun ti u module ta tm c hm truyn b iu khin
dng:
ss
1 . . 1.(1 ). 2 . . ..2. .
u u ui
cl i cl i u
u
T s T RR
K K K K T T sT s
R
+= = +
- V hm truyn kn ca mch vng dng in l:
2 2s s
1/
1 2. . 2. .i
i
KF
T s T s=
+ +
Trong :
Ki: H s phn hi ca sensor dng. Chn Ki = 1.Klc: H s khuch i b chnh lu. Chn Klc = 15.
Tdk: Hng s thi gian iu khin Tiristor. Tdk=0.01.
Tv: Hng s m van Tiristor. Tv = 0.01.
- Ta c cu trc mch vng iu chnh dng in:
Hnh 2.5. Cu trc mch vng iu chnh dng in
+ Cu trc mch vng iu khin tc .- Xut pht t hm truyn kn ca mch vng dng in:
2 2s s
1/
1 2. . 2. .i
i
KF
T s T s=
+ +
Do Ts rt nh nn Ts2 0 s
1/
1 2. .i
i
KF
T s=
+
9
7/30/2019 BI TP LP A Qun
10/15
- Ta c hm truyn i tng trong mch vng tc c dng:
s
.( )
.(1 2. . )( . )t
i f
K KS s
K T s J s B
=
+ +
- B qua h s momen nht Bf ta c:
s
.( ). .(1 2. . ).
t
i
K KS s
K J T s s
=
+
- p dng tiu chun ti u i xng ta c b iu khin tc l:
ss s
. . 1 8. .1.(1 ) .( )
4. . . 8. . 4. . . 8. .i i
t s t s
K J K J T sR
K K T T s K K T T s
+= + =
Trong : K: H s phn hi tc . Chn K = 1.
- Ta c cu trc mch vng iu khin tc :
Hnh 2.6. Cu trc mch vng iu chnh tc .
- Kt qu m phng ta c:
Hnh 2.7. p ng tc trn min thi gian lin tc.
10
7/30/2019 BI TP LP A Qun
11/15
b, B iu khin trn min s.
Hm truyn i tng trong mch vng tc trn min thi gian lin tc s
c dng:
2s
. 19( )
.(1 2. . ).( . ) 0,0144s 0,3724s 0,31
t
i f
K KG s
K T s J s B
= =
+ + + +
Chuyn hm truyn i tng sang min s, ta chn chu k trch mu T=0,05.
Khai bo trn Matlab:
>> Gs = tf(19,[0.0144 0.3724 0.31])
>> T = 0.05
>> Gz = c2d(Gs,T,zoh)
Ta c:
2
1,115 0,7279( )
1, 244z 0, 2744
zG z
z
+=
+
S dng cng c rltool tm b iu khin PID s cho i tng:
11
7/30/2019 BI TP LP A Qun
12/15
Ta tm c b iu khin PID nh sau:
0,3399 ( 0,8)( 1)z zC
z z=
M phng b iu khin PID s:
Vi chu k trch mu T = 0,05.
12
7/30/2019 BI TP LP A Qun
13/15
Hnh 2.8. Cu trc mch iu khin PID s
Ta c m hnh mch vng tc trn min thi gian lin tc:
Hnh 2.9. p ng tc trn min s.
Ta tm c b iu khin PID nh sau:
0,3399 ( 0,8)
( 1)
z zC
z z
=
Kho st s nh hng ca chu k trch mu n p ng tc ca i tng
trn min s.
Ta tin hnh kho st vi chu k trch mu T = 1
13
7/30/2019 BI TP LP A Qun
14/15
Hnh 2.10. p ng tc trn min s vi chu k trch mu T = 1.
Nhn xt:Cc kt qu m phng cho thy p ng trn min s tng t nh p ng
trn min lin tc. iu ny khng nh thut ton v cch thc xy dng b iu
khin s l hon ton ng n v chnh xc. Kt qu cng cho thy vic chn chu
k trch mu khc nhau s cho ra cc p ng khc nhau. Chu k trch mu cng nh
cho php ta thit k c cc b iu khin c cht lng cao. Tuy nhin khng
phi lc no ta cng la chn c chu k trch mu nh, iu ny ph thuc vo
nng lc tnh ton ca thit b, cc thit b ph tr cng nh bn thn h thng cn
iu khin.
Khi chu k trch mu T cng ln th cht lng ca h thng cng km dn i
ri dn n mt n nh.
14
7/30/2019 BI TP LP A Qun
15/15
Ti liu tham kho
[1] GS.TS Nguyn Phng Quang
iu khin s (Digital Control System) i hc Bch khoa H Ni 2007
[2] Harmonic drive actuator Precision Gearing & Motion Control
DC Servo System RHS & RFS Series
[3] GS.TS Nguyn Phng Quang
Matlab & Simulink dnh cho k s iu khin t ng Nh xut bn khoa hc v
k thut 2006
[4] Nguyn Don Phc
L thuyt iu khin tuyn tnh Nh xut bn khoa hc v k thut 2009
15