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iu khin cc thit b in t xa qua mngInternet

Phm Duy Hng

Trng i hc Cng nghLun vn Thc sngnh: K thut in t; M s: 60 52 70

Ngi hng dn: PGS.TS Trn Quang VinhNm bo v: 2012

Abstract: Nghin cu v thit k h thng iu khin t xa thit b in qua mng

internet. Tm hiu cm bin o dng in s dng hiu ng Hall. M t vi iu khinPIC16F877A. Nghin cu khi giao tip v truyn d liu E2U (Ethernet to UART).Cc phng php o dng in xoay chiu. Tin hnh thc nghim: cc bc thchin v kt qu.

Keywords: K thut in t; Thit b in; Cm bin in; Mng INTERNET

ContentPHN 1: L THUYT

CHNG 1: NGHIN CU V THIT K H THNG IU KHIN T XATHIT B IN QUA MNG INTERNET

1.1. Nguyn l hot ng ca h thngDi y l hnh 1 trnh by s nguyn l hot ng ca h thng iu khin ng ngtthit b ta nh qua mng Internet.

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Internet

Router

Ngi dng

Ngi dng

Ngi dng

Tng la

Mng Ethernet Cn h Port 1024

HW

Cn h Port 1028

TV

nL vi sng

My gitT lnh

Module iukhin

IP: 203.113.130.218

TV

My gitT lnh

Module iukhin

HW

Cn h Port 1026

TV

nL vi sng

My gitT lnh

Module iukhin

Hnh 1.1: S hot ng ca h thng iu khin thit b qua mng Internet

Trong s ny, cc thit b trong mi cn h ca ta nh nh bng n, my git, tivi, tlnh, l vi sng... s c kt ni n cc u vo/ra ca b iu khin. B iu khin ny sau c kt ni ti b nh tuyn (Router) ca ta nh thng qua mng Ethernet LAN ri t kt ni vi Internet. Mi b iu khin trong ta nh c xc nh bi cp a ch IP -Portca router , do cc my tnh bt k trn mng Internet c th kt ni chnh xc ti mi biu khin ny. Ngi dng, vi phn mm c ci trn my tnh, khi kt ni vi Internet cth truy cp vo h thng v tng tc iu khin cc thit b mt cch d dng. Vic iu

khin y l hai chiu, trong , ngi dng khng ch n thun gi lnh iu khin ngngt m cn c th gim st c thit b nh thng tin phn hi t cc thit b v trng thilm vic hin ti . Chi tit cu trc phn cng v phn mm ca h thng se trnh by sau y .

1.2. Nguyn l lm vic ca module iu khinM un iu khin t xa qua mng Internet c trnh by trong hnh 1.2 d i y:

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RJ45

HR911105A

Vi iu khin

PIC18F67J60-I/PT

Vi iu khinPIC16F887A

Tng cng sutThit b cniu khin

Khi E2U Khi PaCEthernet

Khi phn hi

H

nh 1.2: S chc nng b iu khin qua mng InternetTheo s , b iu khin bao gm 2 khi: khi E2U (Ethernet to UART) giao tip vi mnginternet v truyn d liu u ra theo chun RS232, v khi PaC ( Process and Control)thc hin vic x l d liu ri xut tn hiu iu khin thit b qua tng cng sut, khi phnhi s dngvi x l ACS712.Hthng c m t nh sau:

Module Ethernet lm nhim v chuyn cc k t nhn c t Ethenet (ng IPv Port) ra cng UART ca module v ngc li.

PIC 16F887 s nhn cc k t t module Ethernet, phn tch cc k t v a raquyt nh ng m r le tng ng.

IC ULN2003 lm nhim v m dng iu khin r le Module phn hi dng cm bin ACS712 lm nhim v nhn bit dng in i

vo thit b, a tn hiu v h thng.

1.3. Phn tch tnh nng phn hica h thngH thng yu cu thit b phi c phn hi trng thi u ra v trung tm bng cch cm nhn

dng in tiu th ti li ra.

CHNG 2: NGHIN CU V TM HIU CM BIN O DNG IN SDNG HIU NG HALL

2.1 L thuyt v hiu ng Hall:Hiu ng Hall l mt hiu ng vt l c thc hin khi p dng mt ttrng vung gc

ln mt bn lm bng kim loi hay cht bn dn hay cht dn in ni chung (thanh Hall)

ang c dng in chy qua. Lc ngi ta nhn c hiu in th (hiu th Hall) sinh

ra ti hai mt i din ca thanh Hall. T s gia hiu th Hall va dng in chy qua

thanh Hall gi l in tr Hall, c trng cho vt liu lm nn thanh Hall. Hiu ng ny

c khm ph bi Edwin Herbert Hall vo nm 1879.

2.2 Gii thiu vi mch Hall cm bin dng ACS712IC cm bin dng tuyn tnh da vo hiu ng Hall, c tch hp y vi cht dn

dng in tr thp v cch in 2.1kV RMS.

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Dng ng gi v s khi

ACS712 c ng gi theo dng SOIC-8

Hnh 2.3:Vi mchACS712

Hnh 2.4: S nguyn l mch cm bin ACS172Nhn s trn ta thy bn trong cm bin c tch hp sn b b th offset v cc bkhuych i tn hiu. T lc CFkt hp vi cc tr ni to thnh b lc RC ngay trc bm u ra gip gim suy hao do st p trn b lc. ng thi t CFcng xc nh bandwidthca cm bin.

c im:

ng tn hiu analog nhiu thp. Bng thng ca thit b c thit nh thng qua chn FILTER mi. Thi gian tng ca ng ra p ng vi dng ng vo l 5s. Bng thng 80kHz. Tng li ng ra ti TA = 25C l 1.5%. Dng ng gi SOIC8 vi cc chn nh. in tr dy dn trong 1.2m. in p cch in ti thiu 2.1kV RMS t chn 1-4 n chn 5-8. Ngun vn hnh n 5V.

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nhy ng ra t 66 n 185mV/A. in p ng ra tng ng vi dng DC hoc AC. in p offset (lch) ng ra cc k n nh. S tr t gn bng zero. Ng ra t l trc tip vi ng vo t ngun cung cp.

M t v IC:

ACS712 Allegro cung cp gii php kinh t v chnh xc cho vic cm ng dng AChoc DC trong cc h thng cng nghip, thng mi v lin lc. Dng ng gi ca thit bcho php ngi s dng d dng lp t. ng dng tiu biu bao gm iu khin ng c,qun l v pht hin ti, ngun cung cp ch switch, v bo v li qu dng. Thit b nykhng s dng cho cc ng dng trong t.

Thit b bao gm mch in Hall tuyn tnh, lch thp v chnh xc vi ng dy dnng c t gn b mt ca lp v. Dng in c cung cp i qua phn dy ng s tora mt trng in t m IC s chuyn i thnh in p tng ng. Thit b c ti u hamt cch chnh xc thng qua cc tn hiu t rt gn n b bin i Hall.

Mt in p tng ng (proportional), chnh xc c cung cp bi IC Hall BiCMOS lch thp, b to xung c n nh m c lp trnh chnh xc sau khi ng gi.

Ng ra ca thit b c 1 cnh (sn) dng (> VIOUT(Q)) khi tng dng in i qua phndy ng th cp (t chn 1 v 2, n chn 3 v 4), l phn c dng ly mu dng in.in tr trong ca phn dn in ny l 1.2m, tiu th ngun thp. B dy ca dy ng cho

php thit b c th chu c n 5 ln iu kin qu dng. Cc u ca phn dn in ccch in vi cc u tn hiu (chn 5 n chn 8). iu ny cho php ACS712 c dng

trong cc ng dng c yu cu cch in m khng dung opto cch in hoc cc k thutcch in t tin khc.ACS712 c cung cp trong dng ng gi SOIC8 dng b mt nh. Cc khung chn

ca thit b c m vi 100% thic m n ph hp vi tiu chun RoSH. Thic b ny chiu chun y ti nh my trc khi xut xng.

CHNG 3:VI IU KHIN PIC16F877A

Vi iu khin PIC16F877A c s dng trong lun vn ng vai tr l IC iu khin

ton b thit b. Cc ti liu chi tit v vi iu khin ny c nh sn xut cung cp y trn trang ch ca hng [5].

c im c bn ca h vi iu khin PIC16F877A

Dng PIC16F877A c rt nhiu chc nng mnh, nhng trong gii hn ca ti, tich tp trung tm hiu v:

- c im tng qut.- S khi, s chn, chc nng ca cc chn.- Cc c im ni bt ca cc cng vo ra.- Cch t chc b nh, gii thiu cc thanh ghi hay dng trong qu trnh lp trnh.- B chuyn i tn hiu tng t sang s.

- Cc giao tip truyn thng SPI, UART.

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3.1. c im tng qut ca vi iu khin PIC16F877APIC16F877A l mt trong 4 dng vi iu khin 8bt ca Microchip ra i nm 2007

vi nhng c im in hnh nh sau:Vng hot ng:

- in p nui thp: t 3,0 n 5 V.- Xung nhp h tr t 1 n 5 MIPS.- Di nhit hot ng t -40oC n 125oC.

Vi iu khin hiu sut cao:- C kin trc Harvard.- Tp lnh ti u cho trnh bin dch ngn ng C.- 8 btd liu, 24 bt cho lnh.- B nh chng trnh c th nh a ch ln ti bn triu t lnh. - B nhd liu: 64 kbyte.- 83 tp lnh c s, hu ht x l trong mt chu k. - Hai b tch ly 40 bt.- H tr php nhn chia 8 bt.

Truy cp b nh trc tip:- H tr n tm knh.- 2 Kbyteb nh m.- Hu ht cc ngoi vi u h tr truy nhp b nh trc tip.

B nh thi / B so snh/ B iu ch rng xung - C n nm b nh thi 8 bt, cho php ghp hai b thnh b nh thi 32 bt.- Mt b nh thi chy vi thnh anh ngoi 32,768 kHz. - Bn b FIFO cho mi b bt tn hiu. - B so snh 8 bt.

B iu khin ngt:- tr nm chu k my.- H tr 53 ngun ngt, ba ngt ngoi, by mc u tin lp trnh c.

Cng vo ra s:- Cho php chn chc nng ngoi vi ca tng chn. - 31 chn cho php nh thc vi iu khin khi pht hin thay i in p.- Cc chn li vo u h trn 5V.- Cc chn li ra h tr ra ngun 5V ch cc gp h.

Flash v SRAM:

- Flash 8 kbyte.- SRAM: 256 byte.- B nh flash chia thnh cc phn Boot, Secure, General Security.Qun l h thng:- C nhiu ch ly xung dao ng. - B n ngun 2,5V c t ngay trn vi iu khin.

B chuyn i tng t sang s:

-

10 bt: Tc 1,1 Msps.- 12 bt: Tc 500 ksps.

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- 9 knh ADC, c th nhn ADC trong ch ng.B chuyn i s sang tng t:- 8 bt, hai knh.- Tc ly mu ti 100 ksps.

Cng ngh CMOS:- Tiu th nng lng thp, cng ngh Flash tc nhanh.

Cc ngoi vi giao tip:- SPI: 8 bit, 8 bt, h tr tt c cc nh dng ng h ni tip.- I2C: Cho php nh a ch 7 bt, 10 bt. Kh nng d v phn x xung t ng

truyn.- UART: c hai b, rng FIFO bn k t.- CAN: 32 b m nhn, 16 b lc nhn, ba mt n.- PMP: H tr tm b, 8 btd liu, 8 btng a ch.- CRC: C 8 byte hng i, 16 bit cho d liu u vo.3.2. S khi, s chn, chc nng ca cc chn3.3. Cc cng vo ra3.4. Cc module giao tip3.5. T chc b nh

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3.6. Cu hnh dao ng ca PIC16F877ACHNG 4: KHI GIAO TIP INTERNET V TRUYN D LIU E2U

Khi E2U c thit k ch yu bao gm u ni RJ45 HR911105A [1] ca hngHanrun v vi iu khin PIC16F67J60-I/PT [2] ca hng Microchip.

Hnh 4.1: S mch nguyn l ca khi E2U

CHNG 5: CC PHNG PHP O DNG IN XOAY CHIU

5.1 Phn loi cc phng php o dng in xoay chiu

c 3 phng php l:

- o trc tip: dng cc dng c o dng in nh ampe k, o trc tip v c k tqu trn thang chia ca dng c o.

- o gin tip: dng volt k o in p ri trn mt in tr chun mc trong mch cdng in chy qua, thng qua phng php tnh ton s c c gi tr dng in cn o.

- Phng php so snh: so snh dng in cn o vi dng in mu, trng thi cnbng ca dng in cn o v dng in mu, s c c kt qu trn mu.

Da vo cc c tnh ca dng in th ta c nhng loi phng php o dng sau:

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- Phng php o th st trn mt in tr shunt. in tr ny thng c chnh xccao. in p st qua in tr t l thun vi dng in cn o.

in tr Shunt

Dng in cn o

Hnh 5.1:Nguyn tc o dng bng in trShunt

5.2 Thut ton o dng in xoay chiu hiu dngin p ca cm bin ra tuyn tnh t 0V n +5V tng ng vi dng vo t -20A n +20A(Dng vo 0A th th ra l +2.5V).

Viout = + 2.5 (Vol)

I = 8*Viout20 (Ampe)u ra ca cm bin c ni vo ADC ca vi iu khin nn in p Viout c tnh nhsau:

Viout = 5* (Vol)

Trong Vref ca ADC l +5V, phn gii ADC l 10 bit.

Dng in hiu dng c tnh theo cng thc:

IRMS =

Trong I(i) l cc mu ca dng in xoay chiu. N l s mu ly trong mt chu k, N cngln kt qu cng chnh xc.

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Thut ton o dng hiu dng cho li in 50Hz:

ng

i = 0

Delay 1ms

i = 20

I(i) = read ADC

IRMS =1N I(i)Ni=0

i ++

Sai

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PHN II: THC NGHIM

CHNG 6: CC BC THC HIN V KT QU

6.1. Thit k ch to phn cng h thng

Hnh 6.1: S mch ca h thng

M t h thng:

Cc li ra xoay chiu s c ni tip vi cm bin ACS712. Cc cm bin nyc cp bn ngun +5VDC v tnh hiu li ra t l tuyn tnh vi dng in qua

cm bin.

Cc u ra in p ca cm bin c c bi b ADC ca vi iu khin PIC16F887. T vi iu khin bit c gi tr dng in ti (IPEAKv IRMS)

Gi tr dng in o c s c so snh vi ngng quyt nh ni dungca gi tin phn hi v trung tm.

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Nu s dng thm mt bin p h th ni vo 220VAC va cp ngun 1 chiucho mch, va h tr o in p ca li in xoay chiu th ta c th tnh c

cng sut tiu th ca ti vi chnh xc nht nh.

ng gi thit bHnh nh c th ca cc bo mch sau khi c lp rp cc linh kin v hp thit b c trnh

by trong cc hnh 6.9, 6.10, 6.11, 6.12

Hnh 6.9:Mt trn bo mchca thit b

Hnh 6.10:Mt dibo mchca thit b

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Hnh 6.11:Hnh chi tit v tr 4 cm bin ACS712

6.2. Thut ton cho phn mm iu khin

6.3. Phn mm giao din iu khin trn my tnh PCPhn mm giao din c vit bng ngn ng VB6. Bao gm mt s chc nng c bn: - Nhp a ch IP v PORT ca thit b cn kt ni.- Hin th gitr dng in nhn c t thit b.- C nt bt tt bn thit b tng ng.

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6.3.1 Giao din chng trnh

Hnh 6.13: Giao din chng trnh

6.3.2 Giao din chng trnh khi hot ng

Hnh 6.14: Giao din khi m ti l bng n 25WKt quthc nghimiu khin thit b in t xa qua mng Internet nh sau:

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- Thit b p ng lnh iu khin t my tnh trong thi gian di 1 giy (th nghimkt ni t xa qua mng Internet ca VDC v qua 3G ca Mobifone).

- Thc hin php o dng in tiuth trn thit b bng phn mm iu khin cho gi trsai s di 4% so vi gi tr o c trn ng h Multimeter.

PHN 3:KT LUN V HNG PHT TRIN TI

CHNG 7: NHNG VN GII QUYT V NGHIN CU C QUALUN VNSau qu trnh thc hin lun vn, ti tm hiu v gii quyt c nhng vn l:-Nghin cu v thit k h thng iu khin t xa thit b in qua mng internet c tnh nng

phn hi trng thi hot ng ca thit b- Tm hiu cc phng php o dng in xoay chiu. S dng c IC o dng in chuyndng nh ACS712. o c gi tr dng in xoay chiu trong khong thi gian di.

- Tm hiu cu trc phn cng cng nh lp trnh kim sot mt vi iu khin PIC16F877A.T xy dng thnh cng h thng o dng in xoay chiu vi tin cy t c trongthi gian di.- Tm hiu v lp trnh giao tip vi m un ETHERNET TO UART qua cng giao tip nitip khng ng b UART.- T cc kin thc nghin cu, h thng o dng in c ti xy dng bao gm phncng v phn mm qun l vi nhng tnh nng sau:

1.1. V phn cng:+ Thit b cho php ngun nui c in p vo di rng, ln ti 60V.+ C cc linh kin bo v thit b khi ngi dng cm ngc ngun.

+ Nh vic h tr cc giao thc truyn thng ethernet, thit b d dng ghp ni vo cc mngiu khin cng nghip.+ H tr cc cng g ri, thun tin cho cc k s pht trin sa cha, nng cp firmware.

1.2. V phn mm:+ Phn mm n gin, trc quan, thn thin vi ngi dng. N th hin qua vic b t r ccnt bm chc nng, th hin th.

1.3. Nhng vn cn tn ti ca ti v hng gii quyt.Gim thiu sai sphp o:Nguyn nhn sai s xut pht t hai yu t chnh- Bn thn thit b o c sai s do qu trnh ly mu ADC.

- Cm bin o dng cng gy ra sai s c bit l vi cc dng din c gi tr nh. Cch khc phc:S dng nhiu u o v ly gi tr trung bnh ca cc u o. Trn mi u o, phn mm sc tch hp thm phn lc nhiu ADC bng cch ly nhiu mu v chia trung bnh, s dng

b lc thng thp bc ba vi mt nghn mu u vo.Bo mt d liu v m bo tnh ton vn ca d liu.Nguyn nhn:

- Mng Ethernet i khikhng n nh, lm mt gi tin trong qu trnh kt ni.- D liu c gi i di dng vn bn.Cch khc phc:- Tch hp thm c ch sa li v bo nhn vi tng bn tin. 1 bn tin c th c gi nhiu

ln- M ha bn tin trc khi gi bng thut ton o m k t.

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- Chn thm thng tin v tnh CRC, checksum v. v

1.4. Hng pht trin ca bi lun vn

ti xy dng c nhng nn tng ban u ca vic gim st v truyn d liu v ccthng s ca in nng thng qua mng ethernet. Trong tng lai, p dng vo thc t,

thit b cn ti u ha phn cng, gim thiu sai s o lng, loi b cc khichc nngkhng cn thit h gi thnh sn phm. ng thi sn phm cng phi h tr cc h tngmng tin tin nh GPRS/3G, m bo tc nhanh v khng b mt d liu, chi ph r.Gii php ny sau khi c hon thin s c kh nng thay th cc gii php ghi s liu innng truyn thng. ng thi n cng xy dng c c s d liu ln phc v cho vic phttrin cc dch v gi tr gia tng khc.Phn mm qun l phi c vit li di dng ng dng web hoc h tr chy trn cc nntng di ng phc v s ng ngi dng. Ngoi ra, phn mm cng s c tch hpthm cc tnh nng mi nh d on v cng sut tiu th, a ra cc gii php tit kim incho tng khch hng da trn c s d liu v thi quen s dng ca khch hng.

References1. Tran Quang Vinh, Pham Manh Thang, Phung Manh Duong, Controlling

Communication Network in the Building Automation System, Journal ofScience,Vietnam National University, pp.129-140, Vol.26, 2010.

2. Nguyn Kim Giao (2004),K Thut S, NXB HQG.3. Trn Quang Vinh, ti Nghin cu thit k, ch to cc cu kin v h thng t

ng ha phc v gim st, iu khin, iu hnh cho cc ta nh cao tng (nh cng

ch v dn dng), m s: KC.03.12/06-10.

Website:4. http://www.alldatasheets.com

5. http://www.microchip.com

6. http://www.picvietnam.com

7. http://www.hanrun.com/hren/product.asp?id=322