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7/30/2019 BI TP LP A Qun

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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)

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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

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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 )

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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

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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:

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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

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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

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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:

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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=

+

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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.

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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:

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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.

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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

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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.

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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

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