85.nghien cuu thiet ke he thong cam bien vi tri

Cng ty TNHH Tin hc v in t Thng Long M s ti: L/05-2011-2 ti: Nghin cu, thit k v ch to xe siu trng siu trng, mu 150 tn Chuyn : Nghin cu thit k h thng cm bin o v tr

MC LCI. MC CH, YU CU..............................................................................................................................3 I.1. Mc ch...........................................................................................................................................3 I.2. Yu cu.............................................................................................................................................3 II. THC HIN NGHIN CU THIT K ...................................................................................................4 II.1. O CAO TRC NNG H ...........................................................................................................4 II.1.1. Yu cu o....................................................................................................................................4 II.1.2. Phng php o...........................................................................................................................4 II.1.2.1. La chn i tng o v php chuyn i tng ng....................................................4 II.1.2.2. La chn phng php o....................................................................................................8 II.1.3. Sensor........................................................................................................................................10 II.1.4. H thng thu thp tn hiu...........................................................................................................12 II.1.4.1. Mc ch ca thit k h thng o:......................................................................................12 II.1.4.2. Yu cu i vi thit k h thng o:..................................................................................12 II.1.4.3. Thit k h thng o............................................................................................................12 II.1.5. Lp t sensor........................................................................................................................14 II.1.5.1. Yu cu i vi lp t sensor............................................................................................14 II.1.5.2. B tr lp t........................................................................................................................14 II.1.6. Bo v chng s n mn ca mi trng...................................................................................15 II.2. SENSOR O GC QUAY BNH......................................................................................................15 II.2.1. Yu cu o..................................................................................................................................15 II.2.2. Phng php o.........................................................................................................................16 II.2.3. Sensor........................................................................................................................................16 II.2.4. H thng o v thu thp tn hiu t sensor.................................................................................16 II.2.5. Lp t sensor............................................................................................................................19 II.2.6. Bo v sensor.............................................................................................................................20 III. KT LUN............................................................................................................................................20 IV. TI LIU THAM KHO........................................................................................................................21

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DANH MC HNH VHNH 1. V TR CC SENSOR O V TR..................................................................................................3 HNH 2. K HIU CC TRC NNG H V CM BNH.........................................................................4 HNH 3. O CAO CA SN XE THNG QUA GC M CA KHP NNG H..............................6 HNH 4. V TR CC IM TRN H THNG NNG H NG VI TRNG HP SN XE V TR THP NHT V CAO NHT......................................................................................................................7 HNH 5. M T V TR CC KHP TRN TRC NNG H KHI SN XE CAO THP NHT V CAO NHT..................................................................................................................................................8 HNH 6. O GC BNG PHNG PHP ENCODER. A M T PHNG PHP, B M T A ENCODER...................................................................................................................................................9 HNH 7. O GC THNG QUA O CC S THAY I CA I LNG IN TR.........................9 HNH 8. SRH880P CA HNG PENNY AND GILES...............................................................................10 HNH 9. SENSOR IPS6000 HNG INDUSTRIAL GRADE....................................................................11 HNH 10. SENSOR O GC QUAY CA HNG MOBIL ELEKTRONIK................................................11 HNH 11. S KHI THU THP TN HIU O TN HIU XC NH CAO TRC NNG H.....13 HNH 12. S NGUYN L CA 4 KHI THU THP TN HIU SENSOR O GC NNG H TRUYN TI T IU KHIN TRUNG TM...........................................................................................13 HINH 13. V TR LP T CA 1 SENSOR NNG H...........................................................................14 HNH 14. MI NI CP TRUYN DN M12X1........................................................................................15 HNH 15. SENSOR O GC QUAY CA HNG MOBIL ELEKTRONIK................................................16 HNH 16. S KHI THU THP TN HIU O TN HIU XC NH GC XOAY CA TRC BNH ...................................................................................................................................................................17 HNH 17. S NGUYN L CA 6 KHI THU THP TN HIU SENSOR O GC LI CA TRC BNH TI T IU KHIN TRUNG TM...............................................................................................18 HNH 18. THIT K LP T SENSOR O GC QUAY TI MT CM BNH...................................19 HNH 19. BO V CNG XUT TN HIU CA SENSOR KHI TC NG CA MI TRNG......20

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I. MC CH, YU CU I.1. Mc ch Chuyn nghin cu thit k h thng cm bin v tr c thc hin vi cc mc ch sau: Gim st, iu khin nng h ca cc xi lanh nng h t theo di, iu chnh c cao ca tng trc v cao ca sn xe (1605 mm .. 2310 mm). Gim st v iu khin gc quay ca bnh trong h thng iu khin li (-90 .. +90). S b tr cc sensor c da vo kt qu kho st t xe mu, m t nh Hnh 1.11a 12a 12c 11c 12e Ca vo

Cabin A

CabinB

Ca vo

12b

12d

12f 11d

11b

Hnh 1. V tr cc sensor o v tr 11-a,b,c,d: Cc sensor o cao ca trc nng h 12-a,b,c,d,e,f: Cc sensor o gc quay ca trc bnh xe

I.2. Yu cu Cc yu cu m chuyn phi thc hin l: Tm hiu phng php o. Tm v la chn sensor cho h thng cn thit k Nghin cu, thit k h thng thu thp, x l tn hiu o. Thit k lp t cc sensor vo xe. Bo v chng s n mn ca mi trng ( m cao, nng mui trong khng kh cao,)

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II. THC HIN NGHIN CU THIT K II.1. O CAO TRC NNG H II.1.1. Yu cu o phc v cho vic nng h v iu khin cn bng cho xe lc vn hnh, cn thit phi o c cao ca sn xe v cao ca tng trc nng h. Xe c 4 trc nng h c b tr nh Hnh 2. C 6 cm bnh v 4 cm nng h. 2 cm bnh 2-3 v 4-5, mi cm 2 bnh s chung 1 c cu nng h.N: cm nng h

11

22

23

N:cm bnh xe

A6 5 4

B4 3 3

Hnh 2. K hiu cc trc nng h v cm bnh.

Cc yu cu o: o cao ti 4 trc nng h Gii hn nng h: 0 705mm Sai s o: 1mm

II.1.2. Phng php o II.1.2.1. La chn i tng o v php chuyn i tng ng. H thng trc nng h l mt kt cu gm xinlanh thy lc v cc thnh phn c kh phc v cho qu trnh nng h. o c cao ca sn v cao ca tng trc nng h ta c 2 hng gii quyt: o khng tip xc: s dng cc cm bin nh siu m hoc quang tnh ton khong cch t sn xe ti v tr cm bin o, t xc nh cao cn o.

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o cao ca sn xe thng qua s dch chuyn ca cc xi-lanh thy thc.

Phng php o khng tip xc khng s dng c trong h thng cn thit k, bi n khng n nh v gy phc tp h thng. y ta tn dng s dch chuyn ca cc xi-lanh thy lc. Xi-lanh thy lc l cc h thng kn, ta khng th ch to mch o tnh ton trc tip di chuyn ca piston bn trong. Cc nh sn xut thng cung cp cc b o i km vi tng loi xilanh. Nu khng s dng cc b o sn xut sn, ta phi o thng qua s dch chuyn ca cc c cu khc ri chuyn i v s di chuyn tng ng ca piston trong xilanh. o dch chuyn ca piston thy lc trong h thng nng h ca xe cn thit k, ta c 2 gii php kh thi: o trc tip t xilanh thy lc: ta phi s dng b o lng do nh sn xut cung cp. Cc b o ny c sai s rt nh nhng gi thnh cao. o gin tip thng qua gc m ca khp nng h. Phng php ny c cc u im sau: o Php chuyn i tng ng gia m khp nng h sang dch chuyn ca xilanh l mt cng thc n gin. o Php o gc c chnh xc cao tha mn c yu cu o. o Khng lm phc tp h thng, nh s dng kt cu c kh thit k cho h thng nng h m khng cn cc c cu trung gian khc. o D lp t, thay th. o Gi thnh ca cm bin o gc khng t nh b o cung cp sn bi nh sn xut. T cc phn tch trn v tham kho vi cc kt qu kho st t xe mu, chuyn la chn phng php o gc m ca khp nng h. Php chuyn i tng ng t gc m ca khp nng h sang dch chuyn ca piston trong xilanh thy lc c m t trong Hnh 3.

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Hnh 3. o cao ca sn xe thng qua gc m ca khp nng h

Theo thit k c kh, 2 tam gic ABC v ADE l khng thay i hnh dng trong ton b qu trnh nng h.AB = 490mm; BC = 275mm; AC = 758mm AD = 1007 mm; R EDA = 15

Trong qu trnh nng h, tam gic ABC s quay quanh tm C, im A chuyn ng ko theo s chuyn ng ca E v D. Sn xe c nng ln h xung theo v tr ca D v E. Gi tr thay i ca on BD l chnh l dch chuyn ca pittong nng h. Gi = R BAD l gc m ca khp nng h, l gc gia AC so vi phng ngang, d =BD l di ca xilanh, h l cao ca D so vi mt t. Qu o nng h ca sn xe c th hin trong hnh sau:

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Hnh 4. V tr cc im trn h thng nng h ng vi trng hp sn xe v tr thp nht v cao nht

Kh nng nng h ti a ca sn xe l 705mm. Ti v tr sn xe thp nht: 0 = R B0 A0 E0 = 57.3 0 = R A0Cx = 19.4 d 0 = B0 D0 = 727 mm,

Ti v tr sn xe cao nht m = R Bm Am Em = 113.6 m = R Am Cx = 56.3 d m = Bm Dm = 1184mm

Vy, trong qu trnh sn xe chuyn ng nng h, gc R BAE thay i trong khong t 57.3 ti 113.6 Khi gc khp nng h R BAD t gi tr 1 (Hnh 5), h l cao ca sn so vi im thp nht ca sn xe. Ta c:

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h

H0 H1

h

Hnh 5. M t v tr cc khp trn trc nng h khi sn xe cao thp nht v cao nht

= 1 0 = R B1 A1 D1 R B0 A0 D0 = R A0 CA 1 h = A0 H 0 + A1 H1 = A0 C sin R A0 CH0 + A C sin R A CH1 1 1 h = AC sin 0 + AC sin(1 0 0 )

Cng thc tnh di ca xilanh ti im o bt k l:d 2 = BD 2 = AD2 + AB2 2 AD AB cos R BAD d 2 = AD 2 + AB2 2 AB AD cos

II.1.2.2. La chn phng php o Nh phn tch trn, ta la chn i tng c o trc tip bi sensor l gc m ca khp nng h. y ta s la chn phng php o gc m . Mt s phng php thng s dng s dch chuyn ca gc l: o thng qua b m ha Encoder (phng php quang):

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o Phng php s dng cc b thu pht-pht quang v h thng a c c l c (encoder) v m ha gi tr ca gc cn o. Phng php ny cho trc tip gi tr s dng nh phn. o chnh xc ca phng php ph thuc vo phn gii ca a encoder o Phng php n gin, chnh xc ty chn nhng bn khng tht s cao (do s gi ha ca cc bng n). o thng qua s thay i ca cc i lng in (in tr, in cm, in dung, in th, dng in,) o Khi thay gc cn o thay i, s to ra s dch chuyn v tr cc phn t ca cm bin, lm cho cc c tnh in ca cm bin thay i (nh in tr, in dung,). T s thay i ny ta s tnh ra c gc cn o. o Tn hiu ra l i lng tng t (analog) v c th chun ha v truyn c i xa trong h thng. o Phng php o c c tn tuyn tnh tt, chnh xc v tin cy cao, tui th ca thit b cao, h thng lp t n gin.

a

b

Hnh 6. o gc bng phng php encoder. a m t phng php, b m t a encoder.Rx n Rx= x/n * Rn

x

R0

Rn

Hnh 7. o gc thng qua o cc s thay i ca i lng in tr

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Vi yu cu v tin cy, an ton v s bn b ca ca xe cn thit k, chuyn chn phng php o gc thng qua cc i lng in, c th l s thay i ca in tr. II.1.3. Sensor Mt s loi sensor m nhm nghin cu tm hiu c. a. SRH880P ca hng Penny And Giles

Hnh 8. SRH880P ca hng Penny and Giles

Sensor c thng s nh sau: o Di o: 20 360 o Sai s: 0.4% ton di o Ngun cp: 90 30 VDC o Output: 0 5VDC V: Hp kim nhm v thp khng g, chng n mn bi mi trng nhiu mui. o Chng rung-sc: 10 2000 Hz, 2500g, 12.6gn rms o Gi: 950USD/chic b. IPE6000 Hng sn xut NovoTechnik

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Hnh 9. Sensor IPS6000 hng Industrial Grade

-

Di o: 20 355 Ngun cp: 90 30 VDC Output: 0 5VDC, 4 20mA Sai s: 0.1% ton di V: Hp kim nhm v thp khng g. Chng rung-sc: 50g/11ms Gi: 650USD/chic c. 530 410-A00A00-00 hng sn xut: Mobil Elektronik

Hnh 10. Sensor o gc quay ca hng Mobil Elektronik

Di o: -60 .. +60 in tr: 0 .. 2k Tn hiu ra: 0 .. 5V DC Sai s: 0.1% ton di Ngun cp: 10..30V DC V: Hp kim nhm v thp khng g, chng n mn bi mi trng nhiu mui.

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Chng rung, shock: 50g/11ms Gi: 400USD/chic C nhiu hng sn xut cm bin o gc khc nhau. Theo kho st, cc sensor m xe mu s dng l ca hng Mobil Elektronik. Cc mu sensor ny c hng xe mu nghin cu v la chn. hn ch thi gian tm kim v th nghim sensor, chuyn cng la chn cc sensor ca hng Mobil Elektronik. II.1.4. H thng thu thp tn hiu II.1.4.1. Mc ch ca thit k h thng o: o Thu thp gi tr o t sensor o gc m ca khp nng h o Chuyn i s thay i v in tr thnh s thay i in p o Chun ha tn hiu in p c th truyn c ti b phn x l m khng b mt thng tin. II.1.4.2. Yu cu i vi thit k h thng o: o 4 knh o tn hiu sensor ti 4 khp nng h. o Ngun cp: 12V. o Tn hiu ra: 0-5V o Truyn tn hiu theo chun 3dy II.1.4.3. Thit k h thng o a. S khi thit b Tn hiu c truyn t sensor v t iu khin trung tm bng cp chuyn dng. Ti y, tn hiu c s ha v x l. Cc gi tr v cao nng h c truyn lin tc v my tnh trung tm t ti cc cabin v hin th qua mn hnh.

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MY TNH TRUNG TM

CARDIU KHIN TRUNG TM

CARDIU KHIN NNG H

TRC NNG H THY LC

T IU KHIN TRUNG TM CM BIN O GC KH NNG H P

Hnh 11. S khi thu thp tn hiu o tn hiu xc nh cao trc nng h

b. S nguyn l Cc sensor c k hiu trong bn v thit k l RP402.4, RP402.8, RP402.12, RP402.16 tng ng vi 4 trc nng h 1, 2, 3, 4 ca xe. Tn hiu c thu thp l in p tng ng vi in tr ca sensor ti thi im o.

Hnh 12. S nguyn l ca 4 khi thu thp tn hiu sensor o gc nng h truyn ti t iu khin trung tm.

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II.1.5. Lp t sensor II.1.5.1. Yu cu i vi lp t sensor o Lp t 4 sensor o gc ti 4 khp nng h ca xe. o Xc nh im t ca sensor. o V tr lp sensor thun tin cho vic lp rp, thay th. II.1.5.2. B tr lp t

Trc 1

xilanh Cnh quay

SENSOR

Trc 2

Hinh 13. V tr lp t ca 1 sensor nng h.

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Sensor c lp ra pha mt ngoi ca khp nng h. Sensor c gn cht vi trc khp c ni vi gm xe. Thanh quay ca sensor c gn cht vi trc cn li ca khp quay. II.1.6. Bo v chng s n mn ca mi trng Yu cu: o Chng li s n mn ca mui trong mi trng bn cng. o Chng s xm nhp ca bi, hi nc, Sensor la chn c thit k cho s hot ng trong mi trng c kh nng n mn cao nh ti cc bn cng, cng nh chng bi v hi nc. Vn cn quan tm y l vic chng n mn ti cc mi ni. Ta s dng cp truyn thng u ni kiu M12x1.Mi ni M12x1 c bc bi lp nt cao su bn, m bo ngn cn s tc ng ca mi trng ti ng truyn dn pha trong.

Hnh 14. Mi ni cp truyn dn M12x1.

Cp truyn c cung cp bi nh sn xut v i km vi sensor. di ca cp tn hiu c truyn i m khng b nh hng, theo thit k ca nh sn xut l 10m. II.2. SENSOR O GC QUAY BNH II.2.1. Yu cu o phc v cho vic iu khin qu trnh li xe lc vn hnh, cn thit phi o c gc quay ca trc xe. Xe c 6 cm bnh c b tr nh Hnh 2. C 6 cm bnh v 4 cm nng h. Mi cm bnh cn phi c gim st c lp gc quay Cc yu cu o: o gc quay ca 6 cm bnh

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-

Gc quay: -90 +90 chnh xc: 0.1% ton di.

II.2.2. Phng php o Nh phn tch la chn phng php o gc nng h, ta cng la chn phng php o gc da trn s thay i ca in tr. II.2.3. Sensor T mt s loi sensor o gc dng trong cng nghip c chuyn tm hiu (nh ca hng Penny and Giles, NovoTechnick, Mobil Elektronik,), v t kho st h thng sensor ca xe mu COMETTO SYT 3/2G, chuyn la chn sensor sau: 530 420-A00A00-00 hng sn xut: Mobil Elektronik

Hnh 15. Sensor o gc quay ca hng Mobil Elektronik

Di o: 145 Output: 0 5k Sai s: 0.1% ton di Ngun cp: 0 .. 30V DC V: Hp kim nhm v thp khng g, chng n mn bi mi trng nhiu mui. Chng rung, shock: 50g/11ms Gi: 400USD/chic II.2.4. H thng o v thu thp tn hiu t sensor a. S khi thit b Ging nh khi o gc ca cc khp nng h, tn hiu t sensor s c truyn trc tip v t iu khin trung tm bng cp chuyn dng. Tn hiu thu c dng in

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p tng ng vi in tr sensor ti thi im lm vic. Tn hiu c x l v c truyn v my tnh trung tm t ti cabin hin th.

MY TNH TRUNG TM

CARDIU KHIN TRUNG TM

CARDIU KHIN XOAY TRC BNH

H THNG XOAY TRC BNH

T IU KHIN TRUNG TM CM BIN O GC XOAY TRC BNH

Hnh 16. S khi thu thp tn hiu o tn hiu xc nh gc xoay ca trc bnh

b. S nguyn l Ging nh sensor o gc ca khp nng h, tn hiu t sensor o gc quay ca bnh tr ra di dng in p t 0 5VDC. in p c truyn theo dy cp ti t iu khin trung tm. Ti y, tn hiu in p s c thu thp v x l. Tn hiu in p ny tng ng vi in tr ca sensor ti thi im o

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Hnh 17. S nguyn l ca 6 khi thu thp tn hiu sensor o gc li ca trc bnh ti t iu khin trung tm.

Cc sensor c k hiu trong bn v thit k l RP410.4, RP410.8, RP410.12, RP410.16, RP414.4 v RP414.8 tng ng vi 4 trc nng h 1, 2, 3, 4, 5 v 6 ca xe.

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II.2.5. Lp t sensorTrc quay bnh xe Sensor Tay quay ca sensor Vt c nh

Sn xe

C cu y trc bnh quay

Pit-tng

Hnh 18. Thit k lp t sensor o gc quay ti mt cm bnh

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Sensor c lp c nh vo trc quay ca bnh xe. Thanh quay ca sensor c gn 1 u c nh vi sn xe. II.2.6. Bo v sensor Sensor c c v c l hp kim nhm v thp khng r nn c bo v an ton trc s tc ng ca mi trng (hi nc, mui,). Dy cp s dng truyn dn tn hiu l loi cp chuyn dng, c bc bi vt liu chu c iu kin mi trng khc nghit. u ra ca tn hiu, ni m dy cp v sensor tip xc vi nhau, c bc kn theo chun M12x1 tng t nh vi h thng sensor o gc m nng h.

u ni sensor v cp truyn tn hiu theo chun M12x1

Hnh 19. Bo v cng xut tn hiu ca sensor khi tc ng ca mi trng.

III. KT LUN Chuyn nghin cu thit k h thng cm bin v tr thc hin c ni dung sau: Phn tch la chn phng php o dch chuyn v la chn cm bin cho h thng nng h v h thng li bnh. o o cao nng h ca sn xe thng qua gc m ca khp nng h o o gc quay ca trc bnh bng phng php trc tip Phng php o v sensor c la chn tha mn cc yu cu t ra:

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Php o c sai s t yu cu thit k H thng o hot ng tt trong iu kin mi trng khng kh c nhiu cht n mn Lp t thay th thun tin Gi thnh hp l

IV. TI LIU THAM KHO [1] Nguyn Tn Phc, Cm bin o lng v iu khin, NXB Hng c, 2007 [2] Tin t, Hng dn Altium Designer, NXB Gio Dc, 2009 1. [3] Hong Minh Sn, Mng truyn thng cng nghip, NXB Khoa hc v k thut, 20012.

[4] Hong Minh Sn, C s h thng iu khin qu trnh, NXB Bch khoa H Ni, 2006 [5] G. Webster, The Measurement, Instrumentation and Sensors Handbook (Electrical Engineering Handbook), CRC PRESS, 1999

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85.nghien cuu thiet ke he thong cam bien vi tri

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