m& TlT XA SlT CAM :M;

:M;

XAY DUNG HE DO XA 3D SlT DUNG CAM BIEN LASER DUNG CHO ROBOT DI DONG TlT TRI

3D laser range finder used for autonomous mobile robot

TrAn Thuan Hoing, DJng Anh Vl^t v4 Triln QiianR Vinh TnrcVnu b a i hpc Cdng nghf, Dai hpc QuAc ela lU N(>i

PhAn bivnl: (;S.TS. DAo VSn lii?p, Hpc vi$n Ky thuflt Q u i n s\f

Phin blfn2: TS. Ph^m Minh Tu6n, Vl$n C ong ngh? Thdng I in, \ i^n K H v4 ( N \ i?! Nam

24

Tom tat

Bai bao trinh bay viec xay dung mot he do xa 3D su ding cam bien laser. He do duoc thiSt ke su dung cho qua trinh dinh vi va lap ban dd ciia mot robot di dong tu quan tri. He thdng cho phep thu nhan dugc hinh anh 3D CO chit lugmg cao cua moi truang xung quanh robot. He dugc xay dung tren co sj mgt may do laser 2D quet ngang ket hgp vai mgt ca cau quay goc ngang (pitch) de tao hieu ung quet dgc cho chiim tia laser. De dam bao do chinh xac cua hinh anh thu nhan, tdc do quay dugc on dinh nha mpt h? dieu khidn dgng ca servo PID hoat dgng a muc chuang trinh phan deo nhung. Chuang trinh thu thap va xu ly so lieu tu may do laser vao may vi tinh da dugc phat trien, dam bao co dugc cac hinh anh laser co dg phan giai cao tai 40.000 diem anh vai toe do truyen tin 38.400 baud. Chuang trinh ap dung giai thuat phan doan va trich chgn dac diem hinh anh cung dugc phat trien du dap ung yeu cau lap ban do moi truang trong phong theo thai gian thuc.

Abstract:

This paper introduces a 3D laser range finder. The system was designed for the localization and mapping of an autonomous

Til dpng hoa ngay nay / 1 + 2 , 2012

mobile robot. It permitted to capture 3D- environmental images surrounding robot with high quality. System was built on a 2D laser range finder combining with a pitching scan mechanism in order to create a vertical scanning effect. The stable pitching speed was ensured by a PID servo motor controlling electronic circuit which operated with an embedded program at low-level. A data acquisition and processing program were developed creating high resolution images up to 40.000 pixels which is transmitted at a baud rate of 38.400. The implementation of algorithms for object segmentation and feature extraction was also developed that meets the requirement of the in-door mapping in the real time.

Keyword: Laser range finder, 3D-laser

image, 2D-laser scarmer, PID controlling.

1. Phan m& dau

Viec djnh vi va dan duong cho robot di dgng hoat dgng tu quan tri can cac cam bien do khoang each din doi tugng du nhanh va chinh xac vai gia thanh chap nhan dugc.

Nhung nam gan day, Viet Nam da kha quen

thuoc voi cac cam bien nhu cam bien sieu

am do khoang each true tiep va cam bien anh

(camera lap the) xac dinh khoang each gian

tiep tren ca sa tinh toan cac tga do diem anh.

Ngoai nhimg uu diem ra, cac cam bien nay con CO nhieu nhuge diem lam cho viec ung dung hoan toan chung cho he thong robot di dgng gap phai kho khan [1] [2]. The giai hien da bat dau su dung loai cdm bien laser, dua tren nguyen tac xac djnh thai gian di-ve cua mgt xung laser phan xa tu 'sat can cho phep xac dinh dugc khoang each den vat. Uu diem cua phuang phap do nay dua tren dac diem chum tia sang laser rat hep va it chju anh huong ciia cac thong so moi truong nen neu dam bao dugc phep do thoi gian chinh xac thi cac gia tri khoang each thu dugc ciing rat chinh xac. Thi du, sai so do khoang each cua cac vat c6 duong kinh nho each hang tram met chi co vai cm. Do uu diem nay nen cac may do xa laser da va dang dugc su dung khong chi cho giam sat dieu khien robot di dgng ma con ca cho quan ly cac phuong tien giao thong, xac dinh nhanh kich thudc hanh ly tren bang tai san bay, v.v... Tai Viet Nam hien nay, viec ung dung nay con chua pho bien lam. May do xa laser, ggi tat la LRF (laser range finder) hoat dgng trong dai song hong ngoai vdi cong suat thap khong anh huong den mat ngudi la mgt dien hinh da va dang dugc ap dung hieu qua cho robot di dgng tai phong thi nghiem Robotics tai trudng Dai hgc Cong nghe, Dai hgc Quoc gia Ha Ngi. Trong thiet bi nay, bang each lap them mgt guong quay lien tuc phan chieu chum tia laser nhu H.1, cac xung laser se dugc phat chech di cac hudfng khac nhau vdi cac goc quet fi lech so vdi true tga do jc va tao nen mgt mat phang hinh re quat cua anh sang laser nhu tren H.2. Ket qua nay cho phep nhan dugc mgt trudng so lieu 2 chieu phia truoc cam bien va vi vay thiet bi con co ten la may quet laser 2D (2D laser scanner).

Girong quay

H.1. Tao mat phdng quet ngang tia laser bang guang quay trong mdy do xa laser 2D.

Tuy nhien, thong tin hinh anh 2D dem lai co the khong dii trong mgt so trudng hgp can phat hien cac vat co ket cau khong giong nhau theo chieu dgc nhu H.2 chi ra. Hinh anh 2D thu dugc o day chi cho phep phat hien cac chan ban ma khong phat hien dugc mat ban d vi tri cao hon va cd kich thudc ldn hon nhieu.

z

* Doi tircrnt;

Robot CO 2,iii L R J

^ - ^ ^{-a ii-r:}

Tia

H,2. Mdt phdng tia laser v&i cdc goc quet Trong trudng hgp nay can cd mgt he do xa 3D cho hinh anh moi trudng bao gom ca cac so do ddi tugng theo chieu dgc niia. Nhiing thong tin do se rat can thiet cho cac bai toan tranh vat can va dan dudng toi uu. Mgt so nhdm nghien cuu tren the gidi da co g^ng xay dung may do xa 3D dua tren cac may quet laser 2D re tien hon. Hau het cac giai phap deu Sli dung mgt may quet 2D ket hgp vdi mgt co cau co khi cho phep quay be may theo chieu thu 3. Mgt vai phuong phap quet da dugc su dung vdi cac ten ggi la pitching scan, rolling scan, yawing scan, v.v... [3].

Trong bao cao nay, chung tdi trinh bay ve viec thik ke lip dat mgt he thong do xa laser 3D vdi viec su dmg may quet 2D theo phuong phap "pitching scan" cd mgt su cai tien ve cac ket cau co khi va dien tii nham dat dugc cac yeu cau dat ra cho mgt robot di dgng. Do so lieu tir may quet 2D xuat ra cd

* 1 V f f -y

dac diem la so lieu noi tiep dong bg nen chuong trinh thu thap so lieu phai dugc phat trien dac biet de cho phep bg dieu khien robot thu thap so lieu dugc chinh xac. De su dung cac so lieu nay cho dan dudng robot, cac giai thuat phan doan doi tugng va trich chgn cac dac diem anh trong moi trudng khong biet truoc cd can nhieu ciing da dugc thuc hien nham dap ung yeu cau hoat dgng thdi gian thuc cua robot.

Automation Today /1+2, 2012

25

:ai;

Noi dung ciia bai bao dugc sap xep tuan tyr nhu sau: trudc het trinh bay chi tiet ve ket cau cua h? do xa laser 3D-LRF tren co sd may quet 2D, tiep theo trinh biiy vi?c xay dung phan cung va phdt trien phan mem ghep noi giira he do va mdy tinh nham de cd dugc cac so li?u do chinh xac, cuoi ciing trinh bay ket qua thuc nghiem.

2. Npi dung chinh

2.1 Ket cau hf do xa 3D dun^ may qu^t laser 2D

Mgt may do xa laser 2D loai l.MS-211 cua hang SICK [5] dugc su dung de xay dyng he thong do 3D-LRF May LMS-211 hoat dgng trong dai do xa cue dai la 8m, goc quet ngang 100° cac diem do dugc quet dan tung budc tu 0' tji 100° vdi gde tang dan (dg phan giai) tuy chgn 0,25°; 0,5° hoac 1° May dugc gan len mgt de cd the quay ngang len xudng quanh mgt true nam ngang. He thong cua chiing tdi ciing dugc thiet ke la loai

"pitching scan" nhung co che hoat dgng cua nd cd khac so vdi cac cong trinh da neu ra cua cac tac gia Oliver Wulf et al. [3] va Alastair Harrison et al. [4]. Trong thiet ke ciia cac tac gia dd, LMS dugc gan vao mgt de dugc dieu khien cho quay lien tuc theo mgt chieu. Dieu nay cho phep cd the nhan dugc mgt tdc do quay dn dinh de dam bao cho mgt hinh anh laser thu nhan cd do tuydn tinh tdt theo chieu dgc. Tuy nhien, nd lai dan den viec phai thay the cac day din cap dien va tin hieu lien tuc tdi LMS bang cac vdng cd gdp CO khi tiep xiic dien. Chinh loai tilp xiic nay se sinh ra su bat on dinh ve tin hieu va tang can nhieu ciia he thdng. Ngugc lai, trong he thdng cua chiing tdi, dd oia LMS dugc thiet ke chi quay ngang len-xuong rdi lap lai vdi mgt dai gde nhat djnh nhd hon 1 vdng xoay, va do dd khdng can den cd gdp dien. Trong qua trinh quay ngang len-xu6ng ciia LMS, mat phan^ quet ngang tia laser se dugc ngang len-xudng theo, cho phep thu thap dugc mgt "dam may" cac diem s6 lieu do 3D dugc phan bd trong mgt phin khdng gian ao hinh eau cd ban kinh cue dai la khoang do cua LMS. H.3 cho hinh anh ciia phuong phap quay nay.

H.3. Mdt phdng tia laser v&i cdc goc quet A-

Mdy qudt LMS nang 6kg dugc bat vit vao mgt gia do 337mm x 500mm. Mgt canh gia do dugc gin vdi mgt true xoay nam ngang.

Gia dd dugc gan vdi mgt dau khdp ndi ciia mgt tay ddn, dau kia cua tay ddn cd khdp ndi vdi mgt dTa quay cd dudng kinh <I)120. Khi dTa quay lien tuc, gia do va LMS se quay ngang len va xudng tao hieu ung dich chuyen tia laser theo chieu dgc, ggi la quet dgc. Anh chup cua co cau nay dugc bieu hien tren H. 4.

H.4. Anh chup LMS gdn ket v&i ca (du quay ngdng len-xuong.

Trong thdi gian do, hai tap gia tri ve gde lech ngang p ciia tia laser va khoang each den vat R dugc nhan tu LMS vao may tinh. Moi tap sd lieu ciia mgt mat quet ngang (P, R) se duge ket hgp vdi mdt gde quet ngang a de tinh cac sd lieu tga do cac diem anh. Dua tren cac sd lieu nay, ta cd the xac dinh dugc tga do De-cac cua moi diem anh theo nhu H.5 sau:

v = /?cosarcos^

1 =/?cosasiny9 r = /Jsina

(1)

Doi tuong

H.5. Xdc dinh toa do cua mot diem dnh 3D.

2e

Tv dong hoa ngay nay / 1 + 2 , 2012

H.6 la anh he do 3D dugc dat tren mdt robot di dgng trong phdng thi nghiem.

LMs.-::i

Dicn kJiicn dicn t^i

H.6. He thong LRF gdn tren robot di dong.

I \ 2

1.1. He thong dieu khien mo to* servo va thu thap so lieu tir LMS

De nhan duge mdt hinh anh chinh xac theo chieu dgc, tdc do quay ngang len -xudng LMS can dugc dn dinh vdi mgt gia tri khdng ddi. Tuy nhien, do su bat ddi xung ve co khi cua he thdng dugc thiet ke nen trong qua trinh chuyen dgng, cac nhan td nhu ma sat khdp ndi, trgng lugng vat, v.v... se gay nen su bat dn dinh eiia tdc do quay. Nham khac phuc van de nay, mgt he thdng dieu khien md-to vdng kin servo da dugc thuc hien.

Day la mgt mach vi xu ly dieu khien do rgng xung dien PWM (Pulsed Width Modulation) cip cho md-to theo luat PID (Proportional- Integral-Derivative Control). Phan mem dieu khien dugc phat trien d muc thap (phan deo) nhiing vao vi xu ly nham eho phep qua trinh dieu khien su dn dinh tdc do dugc dien ra dgc lap, khdng chiem dung thdi gian ciia toan chuong trinh dieu khien he thdng robot.

Tdc do md-to dugc do bang viec dem sd xung qua mgt bg alp ma quang 100 xung/vdng gan vdi true quay. Bang phuang phap Ziegler-Nichols, cac he » PID dugc dat la Kp = 6000, Ki = 35 and KD = 20.

Nhim dam bao do tin eay, tdc do nay dugc ghi qua viee liy trung binh 64 gia tri do, mdi gia tri each nhau 5 ms. Su dn dinh ciia tdc do md-to quay nging da dugc kidm tra bdi mgt chuong trinh dugc vilt tren ngdn ngu hinh tugng LABVIEW. H.7 chi ra ring: khi khdng cd di§u khiln PID, tdc do lit mit dn dinh, dac biet tai cac thdi khoang thay doi

hudng chuyen ddng. Ngugc lai, khi cd dieu khien PID, tdc do dugc dn dinh chi vdi bien ddi CO ± 5%.

Num ot measufemenu

H.7. Toe do mo-ta khi khong vd co dieu khien PID.

Dai gde quet dgc a dugc thiet ke trong khoang tu -5" den +20° so vdi phuong nam ngang. May quet LMS dugc dat tren khung robot cao so vdi mat san la 0,4 m nhu chi ra tren H. 8.

Tia VOI a = +20\^-^

^^^"^^^

Tia ven a = -5 ""^^-^.^^^^

D 01 nrcni2 do

,.

z,

Zi-1

0 4 m

vMMwMmmw/MmmwM^mmm/y,

H.8. Goc quet doc a cua LMS.

Viec nhan dir lieu tu LMS de tao mgt khung anh 3D dugc khdi phat tu thdi diem bat dau quet dgc (quay ngang len). Mach dien vdi cac ro-le hanh trinh va mach trigger thuc hien nhiem vu nay. Ggi Tv la thdi gian duge dat cho qua trinh quet dgc cua mdt khung anh 3D, dd la khoang thdi gian md to quay ngang len tu gde a bang -5° den +20° Viec do gde a ung vdi mdi mat quet ngang dugc thay bang viec xac dinh sd mat quet «h trong khoang thdi gian quet dgc 1 khung anh. Gia

r r r

tri nay phu thugc vao mgt sd nhan td nhu tdc do truyen sd lieu ndi tiep baud, do dai sd lieu

f t r

ty le vdi sd diem do trong tung che do quet ngang, thai gian tim kiem cac byte tieu de danh dau ddng bg eho ludng sd lieu, kich thudc bd dem nhd cua LRF va may tinh. Vi

r r r

vay trong he thdng thiet ke, n\, dugc xac dinh bang thuc nghiem qua tdng sd ddng sd lieu quet ngang dugc chuong trinh thu thap trong thdi gian quet dgc. Thuc nghiem cho thay

Automation Today / 2.+2, 2012

21

"^^W^

^{I |i}

:•!;

con sd nay la dn djnh cho mdi che dg nen cd thi suy ra budc nhay Aa cho cdc m^t quet ngang lien ke la:

5° + 20"

Aa =

" A

(2)

Mac du mdy do LMS cd san so lipu do cho mgt mat quet ngang chi sau 13,32 ms, nhung toe do truyen dir li?u ra tdi mdy tinh bj han che bdi tdc do truyen du lieu ndi tiep theo chuin RS-232 la 38.400 baud. So do khoi cdc mach dien tii diing cho dicu khien quet dgc va thu thap so lieu dugc chi ra tren H.9.

TRIGGER USB to COM *—*

R S 2 3 2

data * USB to COM

PID CONTROLLER

ENCODER

USB to COM

PC

H.9. Sa do khoi mach dien tit cua 3D-LRF

2.3. Phat trien chu'oiig trinh cho thu thap

.X.

va xur ly dir lieu trong LRF 3D

• Chuong trinh thu thap va xu ly du lieu tu LRF dugc phdt trien trong mdi trudng Microsoft Visual C++. Sau khi nhan lenh yeu cau truyen sd lieu tu mdy tinh, LRF se giii ve cdc khung du lieu do tuong ung vdi mdi mat quet ngang. Dinh dang dii lieu khung gdm 7 byte tieu de, 2N byte sd lieu vdi 2 byte cho mgt diem do va cudi cung la 2 byte ma phdt hien ldi CRC [5].

7 Header b>tes 2 N Data b>te$ 2 CRC bytes

De dinh vi chinh xde khdi sd lieu do, chuang trinh can phdt hien dugc 7 byte tieu dk trong mdi khung truyen lien tiep. Mudn vay, bg dem nhd ben PC phai dii rgng de chua dugc hon 2 lan sd byte trong mgt khung truyin.

Thi du, vdi che do ddi quet ngang 100°, do phan giai gde 0,25°; se cd 400 dilm do ung vdi 800 byte sd lieu cgng vdi 7 byte tieu dl va 2 byte CRC, thi bg dem cd thi chgn co tu 1.700 din 2.000 byte. Kich thudc nay cung khdng nen ldn qud vi lam cham lai qua trinh

truyin dir lifu. Luu dd ciia chuang trinh thu thap va xu ly dQ- lieu dugc chi ra tren H.IO.

Stan

T

>in l<)nh (Mt chi a<> d o

K iM/i ptiat qua t r i n h xiiiit s o lieu t a lien tuc

Xi^ ly n l i ^ n dang xaii \icii (lc l i r l i i o n o 'li» lien vao

k h r j n y

T,if vy sofiB ioitg

Ooc rac d i e m so lieu t i / tx;

d e m L RF vao Pi Di>^g ')iia I n n h xuat s o lieu la

Xi> ly *6 li*u

J

End

H.IO. Luu do chuang trinh thu vd xir ly so lieu.

• De su dung tap sd lieu thu thap tir LRF

cho cdc muc dich djnh vi hay dan dudng robot, mdt sd cong doan xu ly sd lieu can dugc tien hanh theo thdi gian thuc. Trong sd dd, viec dp dung cdc giai thuat phan doan (segmentation) la rat quan trgng. Xii ly phan doan d day cd muc dich phdt hien va tdch ra cdc tap diem anh ciing nam tren mgt ddi tugng nhu dd vat. ngudri, tudng, hanh lang, v.v...Vdi cdc mat quet ngang 2D, cd nhieu phuang phdp phan doan, nhu phan doan PDBS dua tren khoang each (Point Distance- Based Methods), phan doan KFBC (Kalman Filter-Based) [6]. Chiing tdi da thii nghiem su dung phuang phdp PDBS vdi giai thuat don gian dua tren khoang cdch Euclidean:

If D(ri, r,+i) > Dthd then

segments are separated

segements are not separated

else

trong do, Dthd la miic nguong va D(ri, ri+i) la khodng each Euclidean giira 2 dilm kl can nhau nhu H. 11.

D{Ri, RM ) = V^,'+/?,+,'-2/?,/?,^, cos Ayff

(3)

28

Tv dpng hoa ngay nay / 1 + 2 , 2012

r - ^ ^ ; ' • * * ^ '

Aw=Co+C,min{/?,,/?,.^,}

(4)

C, = V2(l-cosA/?) = ^D{R„RM) I y?, (5)

H-lLP/id/i ifoaw //jeo g/d/ /Awo/ PDAS.

Tu cdc phan doan trong cdc mat quet ngang 2D cd the trich chgn ra cdc diem dac tnmg ciia hinh, thi du nhu tap hgp cdc diem ciing tren mdt dudng thang, ede diem gde, v.v...Cdc diem dac tnmg nay se dugc ghep ndi vdl nhau tao nen mdt eau tnic cdc phan doan trong toan mat 3D.

r

1. 4. Ket qua thvc nghiem va thao luan Tren co sd he do da dugc xay dimg, cdc do dac thuc nghiem thu thap va xii ly dnh laser 3D da dugc tien hanh trong phdng vdi mdi trudng tinh va dgng.

• H.12-a la anh camera mdt ngudi diing yen trong hanh lang dung de so sdnh. H.12-b la anh laser 2D vdi gde quet ngang ciia LRF la 0° (mat phang quet ngang song song vdi mat san). Do LRF dugc dat tren robot cao hon mat san 0,4 m nen chi cd 2 chan ngudi la dugc phdt hien. Trong khi dd, anh laser 3D tren H.12-C cho ta biic tranh ciia toan bd co the ngudi theo chieu cao.

iM^mM'/u.

•iliiin 0-. 1 GOOD r - — 1 p' I — - ^

;uou j 1 ran

•jrn 400D xuu j r n ii?iri

t /

— (

y

I J chmi ,'

j Hop

* f ' i r n

1

1

10 t a x "^0 10O0

(1^)

\

%

K

(a)

(c)

H.12. (a) Anh camera , (b) dnh laser 2D, vd (c) dnh laser 3D.

r

• Nhu tren da ndi, do tdc do quay md to servo dn dinh nen cdc gia tri gde ngang a trong he thdng khdng can phai do true tiep ma dugc dp dat ngay theo cdng thiic (2). Vi vay viec khdo sdt su sai khdc cua cdc sd lieu tga do thu dugc tren co sd do dac va sd lieu thuc la can thiet vi nd cho biet do chinh xdc va tuyen tinh ciia hinh anh. Qud trinh khao sdt dugc thuc hien tren mgt ddi tugng la mdt vat phang duge dat chinh xdc theo phuong thang diing, cdch cam bien mdt khoang da biet la 2.850 mm gidng nhu md ta tren H. 8.

Tai tga do x = 0, cdc ket qua do dac so sdnh giiia gid tri do va gid tri thuc ciia su phu thudc ciia cac tga do y (khoang cdch den vat) va z (chieu cao ciia vat) vao cdc gde ngang dugc chi ra tren cdc H.13-a va 13-b. Sai sd theo true y va z deu cho thay khdng qua 3%.

Sai sd nay nam trong khoang sai so do ciia thilt bi LMS. H.14 la mat cit (z,x) ciia hmh 3D mdt vat hinh trdn dat cdch LRF mdt khoang 2,59 m va biic tudng cdch 2,90 m.

Ket qua true quan cho thay do sai lech la nhd so vdi cdc kich thudc do. Do dd cd the \kx luan la he thdng servo hoan toan dam bao

Automation Today /1+2, 2012

29

BT;

111', I I n ••, I I 1. ll I 1 i I' 1

cho mgt hinh anh 3D cd dg tin cay chip nhan dugc cho ling dyng robot.

3000

Tsao

20OO

ton

I 1000 OD

0 I 400,

\ - Nl]

(till 111 d o vrt jiiii 111 Ihvc lilt it,)ii i1(> V j

(till Iri (ti> vd giii 111 lliv^' tilt- Ipn >tO /

• I -

«

30 3D 10 Of-

i .0

-20

Sai lech s i u a <.a(. u.u\ in dn \i\ m.i tn thuc <• tin cfW loa d d Z ..

•i I I

I l l

. . J . . .

4^

PUchtngMtgd (dtgiw)

H.13. (a) Cdc cap gid trj do (du&ng dirt net) toa do y vd z cua vdt vd gid tri thuc (du&ng lien net) phu thuoc vdo goc ngdng, (b) sai lech tuyet doi ciia cdc gid tri z .

30

11.14.Anh 3D mot vdt hinh tron ddt tru&c LRF

• H.15 la mgt hinh dnh ket qud phan doan cdc ddi tugng tren mgt mat quet phang trong phdng theo gidi thuat PDBS. Do gidi thuat don gian nen qud trinh tinh todn khdng thiy cd dnh hudng den hoat dgng dilu khiln cua robot. Cdc cham trdn la dilm do rdi rac sip xep theo cdc ddi tugng, cdn cdc dudng ndi lien tyc chi ra kit qua feo doan. Tu day cd thi de dang sii dung cdc gidi tiiuat trich chgn dac dilm (nhu giai thuat Hough phdt hien cdc doan thing) d l dung cho trdnh vat can va din dudng robot.

Tv dpng hoa ngay nay /1+2, 2012

H.15. Phdn doan cdc diem dnh theo cdc doi tu^ng.

• He hoat dgng vdi cac thdng sd iing vdi 2 thdi gian quet dgc 7V ngan va dai dugc cho tren bang sau.

Tv

10 s

42 s

Phan giai goc

AP 1.0°

0.5°

0.25°

1.0°

0.5°

0.25°

So mat quet ngang /!

khung 81 40 24 320

160 100

Sd mat quet ngang / 1 giay

8.1 4.0 2.4 7.6 3.8 2.4 Viec chgn thdi gian quet dgc tuy thudc vao timg ling dung. Thdi gian quet cham vdi do phan gidi cao, thi du vdi (Ty = 42 s, Ap = 0,25°), dugc diing cho lap ban dd toan phdng khi robot diing yen. Robot se dung d mgt vi tri va thu thap sd lieu trong 42s de xay dung bdn do toan phdng. H.l6-a la dnh camera de so sanh. H.16-b la anh laser 3D thu dugc.

Ket qud cho thay do chinh xdc, do phan giai va tuyen tinh la chap nhan dugc.

H.16. (a) dnh camera, (b) dnh laser 3D.

mdm'^.„r

De dp dung cho mdi trudng dgng can thdi gian quet nhanh, du vdi (7^ = 10 s, Ap = 1°).

Dd la trudng hgp dung cho robot di ddng trdnh vat can va lap ban do cue bg. H.17 la

w r

ket qua bat anh laser 3D mgt ngudi dang di chuyen ngang qua LRF trong khi robot diing yen va H.18 la trudng hgp ngudi dung tai chd trong khi robot di chuyin vl phia trudc vdi van tdc 0,3 m/s.

.6000 - « "

H.17. .Anh 3D mot ngiroi di ngang qua LRF

H.18. Anh 3D mot ngu&i dimg tai cho trong khi robot di chuyen ve phia do v&i van toe 0,3 m/s.

3. Ket luan

Trong dl tai nay chiing tdi da thuc hien dugc cdc viec sau:

Da thilt k l xay dung thanh cdng mdt he do xa 3D dua tren may do laser 2D dung cho robot di ddng tu quan tri. He thong dugc thiet k l la su kit hgp giiia cdc md dun phan ciing dilu khiln ddng co servo theo luat PID va cac chuong trinh phan mem thu thap sd lieu ddng bg tii he do vao mdy tinh. Chuong trinh

thii nghiem xii ly hinh anh laser nhu phan doan anh ciing da dugc thuc hien.

Cdc ket qua do dac thuc nghiem cho thay he thdng hoan toan sir dung dugc cho cdc nhiem vu dinh vi va lap ban do oua robot trong phdng thi nghiem.

Do tdc do truyen dii lieu ndi tiep theo chuan

r

RS 232 mdi hien chi han che d mic 38,400 baud nen thdi gian quet 1 khung dnh cdn dai.

Irong tuong lai, cd the nghien ciiu dp dung cac phan ciing cho phep nang tdc do nay len

>()0.000 baud de nit ngan thdi gian nay lai va clio phep phdt hien rgng rai hon cdc ddi lirgng ddng quanh robot.

lai lieu tham khao

|i] Zi-xing Cai, Jin-xia Yu, Zhuo-hua Duan, Xiao-bing Zoul Oliver, Bernardo Wagner,

"Design of the 3D perceptive system based on laser scanner for a mobile robot", IJCSNS Intemational Journal of Computer Science and Network Security, VOL.6 N0.3B, March 2006.

[2] Andrzej TypiakHartmut, "Use of lasser rangeriinder to detecting in surroundings of mobile robot the obstacles". The 25 Intemational Symposium on Automation and Robotics in Construction, June 26-29, 2008.

[3] Oliver Wulf, Bemardo Wagner, "Fast 3d scanning methods for laser measurement systemsume". Institute for Systems Engineering, University of Hannover, Germany, 2004.

[4] Alastair Harrion and Paul Newman, "High Quality 3D Laser Ranging Under General Vehicle Motion", Robotics Research Group, University of Oxford, 2007.

[51 Sick AG. : 2006-08-01 Telegrams for Operating/ Configuring the LMS 2xx (Firmware Version V2.30/X1.27), www.sick.com, Germany.

[6] Cristiano Premebida and Urbano Nunes,

"Segmentation and geometric primitives extraction from 2D laser range data for mobile robot applications" Robotica 2005 - Actas do Encontro Cienistisfico Coimbra, 29deAbrilde2005.

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