Khảo sát ảnh hưởng của tân thư trung quốc tới hán văn đông kinh nghĩa thục

MUC LUC

1. Bang giai thich cac chir viet tat
2. Danh sach nhung nguoi tham gia thirc Men da tai
3. Danh muc cac bang so lieu
4. Danh muc cac hinh
5. Tom tat cac ket qua nghien cuu chinh ciia da tai
6. BAG CAO TONG KET
6.1. Dat vanda
6.2. Tong quan cac van de nghian cuu
6.3. Muc tiau vaNpi dung Nghian cimciiaDa tai
6.4. Dia diam, thai gian va phuong phap nghian cuu
6.5. Ket qua nghien cuu
6.6 Thao luan
6.7 Ket luan va kien nghi
6.8 Tai lieu tham khao
7. PHULUC

DAI HOC Q L O C GIA HA NQi
TRUNG fA
OGGbOOOOOgt


f^. . i

1. Bang giai thich cac chir viet tat

MEMS (MicroElectroMechanical System)
ERA (Eigensystem Realization Algorithm)
FRF (Frequency Response Function)

DOF (Degrees of freedom)
FFT (Fast Fourier Transform)
SHM (Structural Health Monitoring)
MAC (Modal Assurance Criterion)
PSD (Power Spectral Density)
MA (Modal Analysis)
MS (Mode Shape)
ODS, OS (Operating Deflection Shape)
SEM (Strain Energy Method)
RPA (Rational Polynomial Approximation)

He vi CO dien tir
Thuat toan dac trung he thong
Ham dap ung tan so
Bac tu do
Bien doi Fourier nhanh
Giam sat tinh trang cong trinh
Dp tin cay theo phuong phap MA
Mat dp pho cong suat
Phan tich dao dpng (rieng)
Hinh dang dao dpng
Dang dp lech khi kich boat
Phuong phap nang lugng
Xap xi theo da thirc hiru ty

2. Danh sach nbumg ngiroi tham gia thyc hien de tai
TT

Ho va ten

1 Tran Due Tan

2

Nguyan Thang
Long

3 Nguyen Phu Thuy

4 Luu Manh Ha

Hoc vi
Thac sy

Tian sT

Co* quan cong tac
Bp mon Vi co dien tir va
Vi he thong

Nhiem vu
Chii nhiem de tai

Bp mon Vi co dien tir va
Vi he thong

Tien sT khoa hpc

Cir nhan

Bp mon Vi co dien tir va
Vi he thong
Bp mon Vi co dien tir va
Vi he thong

Thanh vian

Thanh vian

Thanh vian

3. Danh muc cac bang so lieu
Bang I: So sanh dp phuc tap ciia 2 thuat toan DFT vaFFT
Bang 2: Bang danh gia mot so ciraso
Bang 3: Cac cha dp nhay
Bang 4: He so suy hao tuong ung
Bang 5: LToc lugng cac thong so thong ka diing Monte Carlo va Bootstrap
Bang 6: LToc lugng cac thong so thong ke diing ERA
Bang 7: Tan so cong huong tuong img truoc va sau hu hong

L
L
1!
3:
3;
3'
3*


4. Danh muc cac hinh

Hinh 1 Mot chiac caubi sap
Hinh 2 He thong giam sat liantuc
Hinh 3 Mode shape ddu tian ciia cAu luc truoc (a) va sau khi hu hai (b)
Hinh 4 Do dap ung rung
Hinh 5 Dac trung tan s6 thu dugc diing phuong phap lap: truoc va sau khi hu hai
Hinh 6 So do FFT-8 diem chia 2
Hinh 7 FFT 8 diem
Hinh 8 FFT 2 diem
Hinh 9 Phan tich FFT khi dimg va khong dimg cira so: so sanh ro pho
Hinh 10 Phan tich FFT khi dimg va khong dimg cira so: so sanh dp phan giai
Hinh 11 Tin hieu chim trong nhiau
Hinh 12 Phan tich FFT khi dimg va khong dimg ciraso: tin hieu trpn nhieu
Hinh 13 So do tong quan
Hinh 14Sad6kh6iMMA7260Q
Hinh 15 Cam bien gia toe MMA7260Q vabo mach dieu khien
Hinh 16VidilukhilnDSPIC30f4013
Hinh 17 So do nguyen ly
Hinh 18 Chuong trinh giam sat
Hinh 19 So dd thuat toan
Hinh 20 Ban mach vi diau khien
Hinh 21 Ban mach cam bian gia toe
Hinh 22 Bp tao rung va ban mach cam bien
Hinh 23 He thong do rung
Hinh 24 May phatxung(f= 29.574Hz)
Hinh 25 Kat qua chuong trinh phan tich pho, F =29.9 Hz
Hinh 26 May phatxungf^31.218Hz
Hinh 27 Ket qua chucmg trinh phan tich pho, F = 32.3Hz
Hinh 28 Quan sat tin hieu theo thoi gian tren kenh Z
Hinh 29 Quan sat FFT ciia ca tap dii lieu thu dugc
Hinh 30 Tin hieu thu tran 3 kanh (da dugc triet DC)

Hinh 31 Minh boa va phan bo chuan [11]
Hmh 32 Do cac FRF tran mot cau true xay dung
Hinh 33 Biia chuyendung va bp tao rung [5]
Hinh 34 Cay cau Alamosa Canyon [7]
Hmh 35 Cach bo tri diem vao/ra tren cau (a) nguyan ly, (b) mo hinh trong MATLAB
Hinh 36 Tin hieu thu dugc tran cac nut (mianthoi gian)
Hinh 37 FRF thu dugc tran cau Alamosa Canyon, phep do SISO

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21
21
21
22

22
2A
2A
2f
2
2t
2
2
3(
3(
31
31
3:
3:
3^


Hinh
Hinh
Hinh
Hmh
Hinh
Hmh
Hinh
Hinh
Hinh
Hinh
Hinh
Hinh
Hinh

Hinh
Hmh

38 OS tai mode cong huong dau tien
39 OS tai mode cong huong thu hai f^8.0698
40 Thong so MAC voi 2 mode da tinh toan dugc
41 FRF khi sir dung xap xi theo dathue hiruty
42 OS tai mode cong huong dau tian dung xap xi theo da thirc huu ty
43 OS tai mode cong huong thu hai f=8.0698 (xapxi theo da thue hiruty)
44 Cay c^u 1-40 tai New Mexico [8]
45 B6 tri thi nghiem tran c4u 1-40 [7]
46 FRF tai niitgan (so 3) vamit xa(s6 12)
47 FRF truoc luc saihong
48 FRF sau khi saihong
49 OS ciia cau tai cimg 1 mode cong huong truoc va sau huhong
50 Nguyan tac phuong phap nang lugng theo sue cang SEM [9]
51 Nhan dang sai hong tai vi tri la nut 20 (toa dp X=2500 cm Y=400 cm)
52 Nhan dang sai hong diing phuong phap mem deo

3^
3^
3t
3(
3(
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3^
3^
4(
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41
41


5. Tom t^t cac kit qua nghien cmi chinh cua de tai

Ket qua ve khoa hoc (nhung dong gop ciia de tai, cac cong trinh khoa hpc da cong bo)
Trong thai gian thuc hien dk tai QC 08-13, dl tai da dat dugc nhimg kat qua chinh ve khoa hpc
sau day:
> Tim hieu ly thuylt do rung su dung cam bian gia toe da ap dung vao viec giam sat cong
trinh xay dung (a day la cau).
> Xay dung mot he thong phan tich dir lieu rung, viet chucmg trinh STFT thai gian thuc
tren cam bien gia toe ba chieu phuc vu cho viec giam sat, canh bao.
> Ap dung cac thuat toan xir ly tin hieu nang cao trong viec phan tich dao dpng riang cho
cac mo hinh cau dua tren cong cu DIAMOND/MATLAB.
Cac ket qua tran da dugc cong bo trong hai cong trinh khoa hpc sau day
1. Tran Due Tan, Luu Manh Ha, Nguyen Thang Long, Nguyen Phu Thuy, Huynh Huu
Tue, Land Vehicle Navigation System Enhanced by Vibration Analysis, Research Development and Application on Electronics, Telecommunications and Informatior
Technology, No. 4 - 2008, Posts, Telematics & Information Technology Journal, pp.
11-17.
2. Tran Due Tan, Phan tich rung ddng trong he thong dan duang quan tinh, Ky yau
Hoi thao nghien cim, phat trien va img dung CNTT va truyan thong (ICT.rda'08 ),
Hanoi, 08/2008, tr. 14-19.
Ket qua phuc vu thirc te
Mot phan mam thai gian thuc da dugc xay dung va phat trien. Phan mam nay co tha ket hgp
voi modun chan doan va giam sat dua tren DIAMOND/MATLAB theo phuong phap dao
dpng rieng de phuc vu tot cho viec theo doi tinh trang ciia cau.
Ket qua dao tao

Co mot sinh vian K51 DB da bao ve khoa luan trong thang 6/2009.
Ket qua nang cao tiem luc khoa hoc
> Y)e tai da gop phan phat trian buac dau mot bp phan mam giam sat thai gian thuc,
mot modun phan tich hien trang cong trinh va se tiep tuc dugc khai thac tiep cho
phuc vu nghien cuu va dao tao.
> Da tai da tang cuong kien thuc cho cac can bp ciia bp mon ve xir li tin hieu, giam sa1
cong trinh.


6. BAO CAO TONG KET

6.1. Dat van de
•

Cimg voi toe dp xay dung cac cong trinh cau duang, nha xuong.. .hien nay thi a Viet
nam ciing da xay ra khong it nhimg tai nan sap cau hay sup nha. Tir do co the thay viec
giam sat cac cong trinh xay dung la quy trinh v6 ciing can thiat. Nhiing thanh tuu trong linh
vuc xu ly tin hieu khi dugc ket hgp voi cac kian thirc ve co hpc da cho phep xay dung cac
he thong giam sat cong trinh dang tin cay. Mot trong nhimg nguyan tac truyan thong cua
cac he thong giam sat nay la phuong phap phan tich rung. Phan tich rung dpng co tha dimg
kiem tra su hu hai cua cac cong trinh xay dung va vi tri cua cac diam hu hai nay. Phan tich
rung ciing co the sir dung de xac dinh su xuong cap cua cac cong trinh xay dung sau mot
thoi gian dai dua vao sir dung. Ap dung cac ky thuat phan tich rung co tha dua ra cac thiat
ka xay dung co hieu qua, tin cay hon trong thi cong xay dung dong thoi giiip cho viec thay
the va sua chixa tai cac vi tri chinh xac.

Hinh I Mot chiec cau hi sap

6.2. Tong quan cac van de nghien ciru
Giam sat cong trinh (SHM) dugc dinh nghia nhu chuoi qua trinh thu thap, xir li va

phan tich dn lieu nham tao diau kien thuan Igi cho viec quan li cong trinh xay dung. Cho toi
nay da co rat nhiau cong trinh nghien cuu ve van de nay tuy nhien van con rat nhiau van da
can phai tiep tuc dau tu nghian cuu. Da thuc hien qua trinh giam sat nay thi phai quan sat
dugc dap ung dpng cua he thong trong mot khoang thai gian xac dinh. Viec quan sat dupe
thuc hien nha sir dung mot to hgp cac cam bien dugc lap dat tren cac cong trinh can theo
doi. Nhimg thong tin vl hu hong hien tai (nau co) ciia cong trmh se dat dugc nhof cac kat
qua do luong nay kat hgp voi cac phan tich thong ka.
Voi cac giam sat dai han, thong tin dau ra cua he thong giam sat se dugc cap nhat
deu dan, phuc vu cho viec theo doi tinh trang ciia cong trinh theo thoi gian va cac tac dpng
moi truong. Khi trai qua cac bian co bat nga nhu dpng dat hay qua tai thi SHM dupe dimg


nhu mot he thong giam sat "thai gian thuc" ve tmh trang cua cong trinh. Mot he thong giam
sat lien tuc duoc mo ta nhu tran hinh 2.
Cong trinh

May tinh phu
(xir li tai cho)

To horp cam bien
Thu th^p dSt li^u

Truyen khong da

aZ 3

May tinh trung tarn

m:^.
Phan tich da U^u

va bao cao

Hmh 2 He thong giam sat lien tuc

Nhung phan tich rung thuc nghiem va thong ka la cac phuong phap nhieu trien vpng
cho linh vuc SHM. Nguyan tac cua phep do la do tran be mat cua cau true cong trinh.
Nhimg hu hong se dugc xem la nhung thay doi khac biet ve dac trung he thong khi boat
dpng tot so voi tinh trang hien tai (hoac tuong lai).
Trong thuc te tin hieu rung dpng biau dian trong mien thai gian thuong khong phai la
dang tin hieu dieu hoa ma thuong la mot tin hieu rat phuc tap. Diau nay co nghia rung dpng
thu dugc la do rat nhiau thanh phan rung gay nan. Hay noi each khac do la tong hgp cua
nhieu nguon rung khac nhau.
Mot phep phan tich rung chi tot khi dii lieu sir dung la dii tin cay, do do thiat bi dimg
de thu thap dxt lieu la rat quan trpng. Co ba loai thiat bi co tha dimg de do luong va theo doi
rung dpng: dau do dich chuyan, bp bien doi van toe va gia toe ka. Moi mot thiet bi do co
mot gioi ban va ung dung riang trong do do gia toe la phuong phap tot nhat de xac dinh lire
tir cac may rung. Cam bian gia toe se bien doi cac nang lugng co hpc thanh tin hieu dien.
Dac diam noi bat ciia cac cam bian gia toe MEMS la chat lugng tot va gia thanh re nen da
ung dung vao thuc ta dai song.
Phuong phap rung co the dugc mo ta ban dau bang phuong trinh ciia dinh luat II
Newton. Trong mo hinh nay chung ta can quan tam tai ngoai luc va dap ung cua he thong
theo thai gian. Nau kich thich cau true boi mot xung (tuong tu nhu go mot tieng chuong)
thi dap ung thu dugc se la mot dao dpng bi suy hao. Co tha thay ro vai tro cua khoi lugng,
dp cung, he so suy hao va dieu kien bien trong bai toan nay.
Dao dong cong huong gay boi su tuong tac giiia tinh chat quan tinh va dan hoi cua
vat lieu trong cau true cong trinh. Tat ca rung dpng dugc coi la ket hgp cua luc va cong
huong. Dao dpng kilu luc bao gom cac noi luc, sir mat can bang, ngoai luc va kich thich
moi truong. Dao dpng cong huong xay ra khi cong trinh bi tac dpng a mot tan so cong
huong nao do cua cau true. Cac mode cong huong phu thupc vao tinh chat cua cau true
cong trinh. Cac tan so cong huong dugc xac dinh boi cac tinh chat vat lieu (khoi lugng, dp

cung, va he s6 suy hao) va diau kien bian cua cau true. Da thay rang khi tinh chat vat lieu


thay doi hoac diau kien bien thay doi thi cac mode cong huong cung bi thay doi (do chinh
la nguyen ly ca ban cua viec giam sat cong trinh theo kiau rung). Tat ca cac tham so rung
thuc nghiem se thu dugc bang each do dac trung tan so cua he thong. Dac trung tan so co
dugc khi tac dpng len cau true cac rung dpng voi tan so khac nhau (hinh 3). Tat ca cac cau
true deu co tai 6 mode cong huong (ba tinh tian va ba quay).

Hinh 3 Mode shape dau tien cua cau luc truac (a) vd sau khi hu hai (b)

Cac thuc nghiem se dugc tien hanh true tiap tran cau va la minh hoa cho tinh huong
dimg phuong phap rung de phat hien thanh cong su hu hai cua cong trinh. Hinh 4 la so do
dap ung rung ciia mot cong trinh xay dung va hinh 5 la minh hoa cho viec nhan dinh he
thong bi hu hai.
Kich thich rung nhan t^o
Rung dong do moi trudng
xungquanh

Giam sat rung

thai

f)^

gian

dap ung xung

J

dap ung
FFT

n.
thuc f

FRF

\ Thong s6 mng:
Noi \ - tin s6
suy / - h? s6 suy hao
/ - mode shape
y

Hinh 4 Do dap img rung

dB

dB

ft

cac dinh gia

/ \

Khong hu hai

He thong hu hai

Hinh 5 Dac trung tan so thu duac dung phuong phap lap: truac vd sau khi hu hai


6.3. Muc tieu va Noi dung Nghien cuu cua De tai
Muc tieu cua de tai nay la ung dung do rung cua cam bian gia toe ba chieu che tac
tren cong nghe vi co dien tir (MEMS) vao cac muc tieu dan dung. Cu the o day la sir dung
cam bien de do rung, phuc vu cho viec giam sat tinh trang boat dpng cua cau.
De dat dugc cac muc tieu tren, tap the nghian cuu cua de tai da thuc hien cac noi
dung nghian cuu dugc trinh bay cu tha trong cac muc dual day.
6.3.1 Phan tich rung diing bien doi Fourier
a. Bien doi Fourier cua tin hieu rai rgc DTFT
Xet tin hieu x(n) la rai rac v6 han, dugc lay mau tir tin hieu tuong tu voi tan so T.
Voi Q= o).T. Ham DTFT dugc dinh nghia nhu sau:
X ( " ) = 2;x(«).exp(-yQ«)

(1

Ta nhan xet thay tuy tin hieu roi rac trong mien thoi gian nhung DTFT lai lian tuc va
tuan hoan trong mien tan so. DTFT chinh la ham phirc theo bian tan so thuc. Ta gpi DTFT
la pho phuc (complex spectrum) hay ngan gpn la pho cua tin hieu roi rac x[n]. Tir day ta
thay can thiat phai xay dung bien doi Fourier roi rac cho truong hgp day x(n) hiru ban.
b. Bien ddi Fourier cua tin hieu rai rgc DFT
Truong hgp x(n) hiru ban, chieu dai N (0 < n < N-1)
Ikjt

Dat Q =

(k 6 Z) ta co bien doi Fourier roi rac cua x(n):
n

X ( k ) = X x(n).e^^"

(2;

Hay
X(k) = 2 x(n)(cos(-^kn) - i sin(-^kn))
(3;
- Lugng phep tinh: DFT phai thuc hien N^ phep nhan phuc va N(N-I) phep cong phuc
Suy ra so phep tinh cong va nhan so thuc:
+ 2N^ phep tinh lugng giac
+ 4N^ phep nhan so thuc
+ N (4N-I) phep cong so thuc
+ Mot so phep toan chi so va dia chi da nap x(n)

10


Nhugc diem: thai gian tinh toan se qua dai va dung lugng nha cua thiet bi se phai
Ion.
c. Bien doi Fourier nhanh FFT
Truong hgp N=2'
TV
Ta chia day x(n) thanh 2 day co chiau dai —:
- Day g(n) gom cac gia tri chan: g(r) = x(2r)
- Day h(n) gom cac gia tri le: h(r) = x(2rHl) trong do r: 0, N 1
Taco:
X(k)N= Y. X W - W H ' " ( W ^ ^ e ^ )

-^

(4)

x(2r+l)^.WN

X(2V)KM^'''^Y.

(2r+l)k

(5)

r=0

= X g(r)^.W^^^ + ^

h(T)K.WK'\w^'

(6)

r-0

2

= X g(r)^.W^* + W N ' . X

h(r)i.W^*

(7)

r=0

G(k) + WN" .H(k)
eCO) - xtP3

0(0)

CCU-XC25

0(1)

( vai k: 0, A^ - 1 )

(8)

y^.
xco>.

\

CDFT)eC2) -

G(2)

KC4)

\ ^

Gt3) \

eC3) - xC6)

^

/ "

\ ^
\ ^ ^

/ \

/ ^

• ^

/W2

JXT

/^W3

X(2>

XC3)

JK

KO) = x a )

H(0)

hCD^'tpS

H(l)

K2) - xp3

fDFT)-

//x\-^

>. V/4

H(2)

/

H(3)

/

/

V V75

\ "

V "we
K 3 : - JtC?:

11

XC6)
XC7)

W7

Hinh 6 Sa do FFT-8 diem chia 2

XC5)


Ta CO thi tilp tuc phan chia moi day g(n) va h(n) thanh 2 day con de giam dp phuc tap
cua DFT
A(0)

g(0) = K(0)

G(0)

(DFT)2

/w.

gC2) = i(4)

A(l)\

g(l) = x(2)

BM/"\

S(3) = x(6)

(DFT)2

m/

G(n

my

\

\ 'll

A^

G(2) \

/\W4

\

0(3) \

\

>/

/

/W2
XC3)

W6

X A / ^^
h(0) = x(l)

HCO)
W.

li(2) = xP)

X(4)

H(l)
XC5)

IXO) /\

K l ) = xC3)
3iC3)=xC7)

(DFT)2

D(l)

,

H(2)

A^^

/

/

Aw?

\

HC3)

W6

/

W6

Hinh

W5

W

7 FFT 8 diem

Cuoi cimg dua ve tinh DFT dcm gian nhat, DFT 2 diem:
a(0) = g(0)=x(0)

A(0),

a(l) = g(2) = x(4)

A(l):
W-

Hinh 8 FFT 2 diem
FFT 2 diam:
A(0) = a(0) + a(l)WN'
A(l) = a(0)+a(l)WN
Hieu qua tinh toan: so phep tinh chi con N.log2N
So sanh hieu qua tinh toan:
12

X(6)


Bang 1: So sanh do phirc tap cua 2 thuat toan DFT vd FFT
Dp dai

So phep tinh

N

DFT

FFT

4

156

8

8

632

24

16

2544

64

32

10208

160

64

40896

384

128

163712

895

256

655104

2048

512

2620928

4608

1024

12327936

10240

Chit v: Hien tugng ro pho (leakage) xay ra trong mien tan so. Ro pho la hien tugng pho cua
tin hieu bi do vao 1 loat cac tan so xung quanh tan so cua tin hieu. Nguyen nhan la do su cat
ngan tin hieu. Khi do tin hieu x(n) khong tuan hoan, tran mian tan so se thu dugc khoang
tan so rpng trong pho FFT.
De giam hien tugng ro pho ta dimg 1 ham cira so nhan voi tin hieu vao de tro thanh tin
hieu tuan hoan. Khi do bian dp moi tan so ly tuong se dugc nam bat chinh xac, khong co ro
pho.

Lua chon ham cua so: Tiiy vao ung dung ta chpn loai cira so se dimg. Dang ham cira so anh
huong rat Ion den dp chinh xac cua viec xap xi ham tan so. Viec chpn ham cira so nao de
xap xi hoa ham tan so, khong chi phu thupc vao dp chinh xac yeu cau, ma con phu thupc
vao ban che ve thai gian tinh toan, vi ham cira so cho dp chinh xac cang cao thi viec tinh
toan se cang phirc tap, va thai gian tinh se cang Ion. Do do viec chpn ham cira so phu thupc
vao su toi uu giiia dp chinh xac yau cau va thoi gian tinh.

13


Bang 2: 3dng ddnh gia mot so cira so

Kiau tin hieu tot
nhat

Cira so

Dp phan giai tan
A

Ropho

Dp chinh xac

so

Batky

Tot

Khong tot

Khong tot

Bat ky hoac tin
hieu phuc tap

Kem

Tot nhat

Tot

Harming

Bdtky

Tot

T6t

Khong tot

Hamming

Bitky

T6t

Khong tot

Khong tot

KaiserBessel

Batky

Khong tot

T6t

Tot

Tin hieu ngan va
lay mau dong bp

Tot nhat

Kem

Kem

Tukey

Batky

T5t

Kem

Kem

Welch

Bitky

T4.

T6t

Khong tot

Barlett
Blackman

Non (boxcar)

d. Mot so ket qua md phong
Chuong trinh 1
Chuong trinh nay nham minh hoa im diem cua viec diing cua so (o day la cira so Harming)
khac phuc hien tugng ro pho. Code dugc trmh bay trong phu luc 7.1.
Kat qua dugc tha hien trong hinh duoi day:

Hinh 9 Phan tich FFT khi diing vd khong diing cica so: so sanh ropho
14


Chvrang trinh 2
Tuy bi nhugc diam la bi ro pho nhung khi(kh6ng)dung cira so thi dp phan giai pho lai tot
hon. Trong chuong trinh nay thi tin hieu can phan tich la tong hgp cua hai tin hieu hinh sin

350 va 352 Hz, dugc lay mau a xkn so 1000 Hz trong thoi gian 0.8 giay (nhiau ban chuong
trinh 1). Code dugc trmh bay trong phu luc 7.1. Kat qua thu dugc nhu hinh duoi cho thay
khi khong sir dung cua so thi viec tach 2 tin hieu hinh sin lai hieu qua hon (dp phan giai tot
hon).

0

220

24D

260

280

300

320

340

360

380 400

Hinh 10 Phan tich FFT khi dung vd khong dung cica so: so sanh do phan gidi

Chuong trinh 3
Tuong tu nhu chuong trinh 2 nhung a day tin hieu bi cong them nhieu tr4ng. Code dugc
trinh bay trong phu luc 7.1. Tin hieu trpn nhieu dugc mo ta trong hinh duoi day, thay ro

rang tin hieu chiu anh huong boi nhiau nang na.

0

0.02

0.04

0 06 0.08
0.1
0 12 0 14
hai tin hieu hinh sin + nhieu

0 16

Hinh II Tin hieu chim trong nhieu

OK


Ket qua phan tich pho cho th^y van co thi nhan hik cac thanh phAn tin s6 khi dimg bien

doi Fourier:
10

10

10
khong cua so
hanning

10

300

310

320

330

340

J

L

350
Hz

360

370

380

390

400

Hinh 12 Phan tich FFT khi dung vd khong dung cua so: tin hieu tron nhieu
6.3.2 Phan citng he thong
So do tong quan

MMA7260Q

DSPIC30f4013

Cong COM
Chuung trinh canh bao

COMPUTER

Hinh 13 Sado tong quan
16


Cac linh kien
Cam bien gia too MMA7260Q vd mach dieu khien
La loai cam bien gia toe dugc cha tao tran cong nghe vi ca dien tu.
+ Dua ra thong so tren 3 true tpa dp X, Y, Z.
+ Gia thanh re de thiet ke mach dieu khien
Bao gom :
+ G-Cell Sensor : chuyen gia toe -> gia tri dien dung
+ Oscillator : bp tao dao dpng
+ Clock Generator : tao xung
+ C to V converter : chuyen gia tri dien dung -> dien ap
+ Gain, Filter : khuach dai va Ipc
+ X, Y, Z temp comp : gia tri tam
+ Control logic EEPROM trim circuits

g-Sefectl

ra

9-Seiect2o-

Cttc<
Generator

Osolabr

Sleep Moce(

G-Côil
Sersor

X-Terrp
Comp

Gair

CtoV
Corvrter

RSer

r

Control Lege

EEPROM TrFT Cira)ts

Y-TfifTD
Corrp

ãOYj,,.

Z-Teirp
Corrp

-OZ-

Vss

Hinh I4Sadokh6iMMA7260Q
Nguyan ly va tinh nang dac biet
Nguyan ly:
+ Khoi G-Cell trong cam bian co cau true 2 tu back-to-baek.
+ Khi gia toe thay doi -> gia tri dien dung thay doi:

C=AE/D

Tinh nang dac biet:
+ Cho phep chpn lira 4 che dp nhay
17

DAI HOC QUOC GIA HA NQI
B > i G J A M THONG TIN rna VIEN

omccC'C0 9z

Bang 3: Cdc che do nhay

g-SeIect2 g-Selectl g-Range Sensitivity
0

0

l-5g

800mV/g

0

1

2g

600mV/g

1

0

4g

300mV/g

1

1

6g

200mV/g

+ Che dp nghi cho Sleep Mode de tiet kiem nang lugng boat dpng o muc tich cue thap.
Khi b cha dp nay dong tieu thu se giam ve muc 3uA
+ Co cac bp Ipc ban trong
+ He so tuyan tinh
Mot so img dung cua cam bian gia toe MMA7260Q:
+ Do va diau khian muc rung
+ Dinh huong 3D trong khong gian
+ Phat hien va cham, nhimg thong tin ve gia toe, van toe va dp dich chuyen giup phan
bi^t viec va cham va khong xay ra va cham.
+ Dieu khien du doan kha nang lam viec cua may moc thiat bj
+ Dpc mot so thong so sinh hpc trong co tha nguoi.
Vi dieu khiin DSPIC30F4013
+ Khoang dien ap rpng 2.5 -> 5.5V
+ Bp chuyen doi A/D 12 bit, 13 kenh loi vao, luon sin sang trong ca che dp Sleep va
Idle
+ Bp nho Flash Ion 48Kbytes, 2Kbytes RAM, 1 Kbytes EEPROM khong bay hoi
+ CPU CO cau true RISC thay cho kian true Harvard
+ It tieu ton dien nang, khoang nhiet rpng
+ Kha nang lap trinh
Ghep noi may tinh bang cong COM (xem phu luc 7.2)
+ Truyan du lieu noi tiap khong dong bp
+ Toe dp truyan nhan cue dai la 10Kbps

Sa do nguyen ly
r

L

.

ã*ã

I

1

ii

1

I

i

i

I

I

I

,

1

I

,

///ô/; 75 C(iw ^/eô g/'o foe MMA7260Q vd bo mach dieu khien
'LJ32.768k

OSCIJCLKIH
OSC2/:XlKJ/RC15
IKTO/RAU
EUUC2XX;lKD0
EMUD2KX:2OC3«D2
OC4/RD3
lCiyiNTlfla>8
1C2/INT2JRD9

AN2JSS1/L VDIH*CH*fl?B2
AK3JCH5/RB3
AH4flC7*c:K6/RB4
AH5nC8*CN7/KB5
PGC«MUC/AN6JOCrA»RB6
PGD/EMUD/AN7/RB7
AN8/RBS
AH9>CSCKJRB9
AHIO^CSDI/RBIO

ANlljCSEXi/RBll
AHI2JCOFS/RB12
CRXl/RTO
CTXl/RTl
D1 RX/SDIlADAJRf::
EMUD3/D1 TX>SDO 1 /SCL/RTS
U2RX;CH17/Rr4
U2TXJCM18/Rr3
EMUC3*SCK1/Rr6

13
20
21
22
23
24
25
26
27
15
14
11
ID

_5
BUT^CLICJiOW
_4
^CLKJtOW
1
SPA

BTl
44 SCL
BT2
3^ Aux_Rx
2
Aux_T..
4 3 LCpB*ckLieht

EMTID1 JSOSClJT2CICai I A T X K N 1 / E C 13
EMTICI JSOSCXiJTl CK/D1ARXJCKOJRC14
DSPIC3DF4013

Hinh 16 Vi dieu khien DSPIC30/4013

19

ADCl
ADC2
AE>C3
TEMPQUT
DATA RED
DATA_GR£EM
PGC E
bCD RW
RS
D4
DS
D6
D7

=^1

^

T

—4 .1 . . I — k

L

<

—

ti

3

EJ'-

fT3'

; * ^ »

dt;

T
t»
//?«/? 17 Sado nguyen ly

Viec can chuan cam bien dugc trinh bay trong phan phu luc ciia bao cao nay.
6*3.3 Cdc ket qua thuc nghiem
Mo ta: tin hieu rung dugc cam bien thu nhan va chuyan thanh tin hieu dien 6 loi ra, roi
dugc dua vao vi diau khian qua ADC, qua day thu dugc tin hieu roi rac thai gian theo 3
chieu. => truyen noi tiap qua cong COM. Cong viec cuoi cimg la cua may tinh, nhan dir
li^u va tinh pho SFFT.
Mo ta chuong trinh:

20


Giam sat rung

Kich thich nhan tao hoac
do moi trirong xung quanh

then
gian

Tinh \

^^^^^ ^P ^ ^ •

toan

-

tan so

Hinh 18 Chuong trinh gidm sat

So do thuat toan:

Nhan du lieu 3 kenh
Tinh pho F F T
Hien thj pho
Tinh F m a x

Hinh 19Sado thuat todn

Tao tin hieu rung boi mot bp tao rung voi tan so rung dugc diau chinh boi may phat xung.
Gin cam bien gia toe lan bp tao rung. Thu dugc mot so ket qua sau:
21


Hinh 20 Bdn mach vi dieu khien

Hinh 21 Bdn mach cam bien gia toe

22


B^ÊM:i:.'

Y

1 ^^'<^.-

ã-

-'All V

1-. -

.-.ã^j'-;.

.,4

Hinh 22 BQ tao rung vd 6flô W4)fc/i caw fe/eô

jH^^-

ãi%:./:

^^Ki

"

^
ã --<^-<'.^>4-i,-a.^

-

*

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1

^

rss^^^;-

ã

ã ' *

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ã

ã

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y^"

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"'^'
f
^^^N^ ^
,

IM^^H
1

Hinh 23 He thong do rung

23

•

,.,*.

^

-

^

^

^

•'

;iÊ888S3*':^^3^ô^' i'-^^ ã'C

Hmh 24 May phat xung (f=29.5 74Hz)

Hmh 25 Ket qua chuong trinh phan tich pho, F =29.9 Hz

24


Hinh 26 May phdt xungf=31.218Hz

Hinh 2 7 Ket qua chuong trinh phan tich pho, F = 32.3Hz

25
•3-»-'W'-,


Nhan xet: kit qua phan tich pho thai gian thuc cua chuong trinh co dp chinh xac tot
(kho^g 3% gia tri do) cho thay kha nang ap dung tot cua chuong trinh cho cac thuat toan
giam sat cong trinh sau nay. Su sai khac 3% co tha dugc giai thich do dp chinh xac cua may
phat song hinh sm, do dp phan giai cua chuong trinh tinh FFT-256,...va co the khac phuc
nho cau hinh phan cung tot hon nixa.
Cac ket qua trong hinh 25, 27 thuc chat la ket qua tinh pho tin hieu tai 1 thai diem xac dinh
FFT-256 diem. Ngoai ra chuong trinh con co tha hien thi tin hieu rung theo thai gian. Tuy
nhien viae lam dung do hoa may tinh se gay nen hao phi tai nguyan (khi di vao thuc ta thi
vi^c hien thi pho theo do hoa nhu hinh 25, 27 la khong can thiet ma chi can cac kat qua luu
tni dugc).
Hinh 28 la ket qua thu tren kenh thang dung - true Z (dugc phong to trong 1 khoang thai
gian ngan de thay dang hinh sin) trong suot thoi gian thir nghiem (hon 30 giay) va hinh 29
la ket qua phan tich pho, cho chinh xac tin so rung la Hz. Da thay rang voi tap du lieu rat

nhieu (6544 mau) thi dang pho thu dugc la cue ki ro net, diau nay phii hgp cac cac ly thuyat
xtr li tin hieu. Ve ban chat each tinh FFT trong hinh 25, 27 la SFFT (Short FFT) mot thao
tac CO y nghia han nhieu voi FFT binh thuong vi co tha mo ta su thay doi ve pho theo timg
thai diem.
2300

0.5

1
thoi gian (s)

Hinh 28 Quan sat tin hieu theo thai gian tren kenh Z

26