Top Banner
HC VIN CÔNG NGHBƯU CHÍNH VIN THÔNG ------------------------------------ LƯU VĂN QUYN SDNG BLC KALMAN TRONG BÀI TOÁN BÁM MC TIÊU CHUYÊN NGÀNH: KTHUT VIN THÔNG Mãs: 60.52.02.08 TÓM TT LUN VĂN THC SĨ HÀ NI - NĂM 2013
24

Tom Tat LV ThS Luu Van Quyen

Dec 18, 2015

Download

Documents

HuyTròn

xxx
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
  • HC VIN CNG NGH BU CHNH VIN THNG

    ------------------------------------

    LU VN QUYN

    S DNG B LC KALMAN

    TRONG BI TON BM MC TIU

    CHUYN NGNH: K THUT VIN THNG

    Ms: 60.52.02.08

    TM TT LUN VN THC S

    H NI - NM 2013

  • Lun vn c hon thnh ti: HC VIN CNG NGH BU CHNH VIN THNG

    Ngi hng dn khoa hc: GS.TSKH. NGUYN NGC SAN

    Phn bin 1:.

    Phn bin 2:.

    Lun vn s c bo v trc hi ng chm lun vn thc s ti

    Hc vin Cng ngh Bu chnh Vin thng

    Vo lc:.gi..ngy.thng.nm..

    C th tm hiu lun vn ti:

    - Th vin ca Hc vin Cng ngh Bu chnh Vin thng

  • 1

    M U Vi s pht trin ca khoa hc k thut. Nhu cu s dng h thng nh v v

    dn ng tr thnh mt nhu cu khng th thiu trong cuc sng ngy nay. T

    ngun gc vic theo di bm st mc tiu hin i ngy nay l s kt hp ca cc

    khoa hc k thut nhn dng mc tiu v phng php theo di i tng, bao gm

    v tr, kch thc, hnh dng vn tc ca i tng. Bm mc tiu s dng cho nhiu

    mc ch khc nhau nh v tinh gim st khng gian c s dng theo di cc

    chuyn ng ca mc tiu nht nh.

    Thi gian gn y vic ng dng b lc Kalman c lng qu o ca i

    tng qua cc khung hnh c s dng nhiu trong cc thit b in t dn dng nh

    Camera gim st, iu hng Robot, d tm mn, thit b kim tra hnh l. Cho n

    nay c nhiu cng trnh nghin cu v lnh vc bm bt mc tiu trn c s x l

    nh v cc thut ton bm theo i tng chuyn ng nh: So khp mu, Mean-

    shift, Camshift, Particle, Kalman Mi phng php c cc u im v nhc im

    khc nhau v cho hiu qu nht nh vi tng loi i tng v mc tiu theo di

    khc nhau.

    Ni dung ca lun vn c cu trc thnh cc phn nh sau:

    Chng I. Tng qut v l thuyt bm mc tiu

    Chng II. S dng b lc Kalman trong bi ton bm mc tiu

    Chng III. V d minh ho

  • 2

    CHNG I: TNG QUT V L THUYT

    BM MC TIU 1.1. Nhng khi nim c bn.

    1.1.1 nh ngha v bi ton bm mc tiu Cho mt i tng (S) c u ra l y(t) trc tc ng ca u vo u(t)

    Hnh 1.1. S ca i tng iu khin vi u vo v u ra

    Bi ton bm mc tiu cn phi tm tn hiu iu khin u vo sao cho tn

    hiu u ra ( )y t bm theo mc tiu.

    1.1.2 nh ngha v sai s Hu nh cc phng php nh gi, c lng tham s m hnh c xy

    dng trn c s p dng nguyn l v k thut tham chiu, trong xc nh mt

    hm sai s phn nh s khc lch gia m hnh v h ng hc thc.

    1.1.2.1 Phng php sai s u ra

    Hm sai s c nh ngha:

    0 ( ) ( ) ( )e t y t y t= (1.1) 1.1.2.2 Phng php sai s u vo

    Trong phng php sai s u vo khng s dng trc tip d liu o lng v

    o hm cc bc theo thi gian ca tn hiu u vo h ng hc nn khng cn phi

    quan tm n c tnh kch thch lin tc nn bi ton c lng tham s m hnh ni

    ring, nhn dng h ng hc ni chung bao gi cng c nghim.

    1.1.2.3 Phng php sai s phng trnh.

    Sai s phng trnh c nh ngha trc tip t phng trnh ng hc ca

    m hnh nh sau:

    ( ) ( ) ( ) ( ) ( )ce t H s y t K s u t= (1.2)

  • 31.1.2.4 Phng php sai s d bo

    Sai s d bo c nh ngha nh sau:

    ( ) ( )( ) ( ) ( ) ( )( )pe

    C s K se t y t u tH sD s

    = (1.3)

    1.1.3 S dng tiu ch ti u

    1.1.3.1 Khi nim

    Ch tiu cht lng J ca mt h thng c th c nh gi theo sai lch ca

    i lng iu khin, thi gian qu hay theo mt ch tiu hn hp trong iu kin

    lm vic nh hn ch v cng sut, tc , gia tc

    1.1.3.2 Tiu ch ti u tc ng nhanh (thi gian ti thiu)

    i vi bi ton ti u tc ng nhanh th ch tiu cht lng J c dng.

    0

    1T

    J dt T= = (1.6) 1.1.3.3 Tiu ch nng sut ti u.

    Nng sut y c xc nh bi cht lng ca h thng bm theo mc tiu

    trong thi gian T nht nh. Khi ch tiu cht lng J c dng.

    00 0

    [ ( ), ), ]T T

    TJ L x t ut t dt tdt = = = (1.7) 1.1.3.4 Tiu ch nng lng ti u.

    Ch tiu cht lng J i vi tiu chi nng lng ti thiu c dng.

    2

    0

    ( )T

    J u t dt= (1.10) 1.1.4 Xy dng khu phn hi. Xt mt h thng c m t bi cc phng trnh u ra v trng thi:

    x Ax Buy Cx= + =

    & (1.11)

    Chn mt lut iu khin c dng:

    ( )u r Kx= (1.12)

  • 4

    x&

    Hnh 1.3: iu khin s dng phn hi bin trng thi

    1.1.5 Xy dng iu khin bm bng phn hi trng thi. Bi ton t ra l iu khin i tng c m t:

    A

    T

    dx x budty c x

    = +=

    (1.17)

    0 1 1

    1 2

    0 0 ... 0 00 0 ... 0

    01

    ( )n

    n

    dx z udt

    a a a

    y c c c z

    = + =

    MM M M

    % % %L

    (1.18)

    Taz

    Hnh 1.4 iu khin bm vi i tng (1.18)

    i tng(1.17)

    STaz x

    u y

    Hnh 1.5 iu khin bm vi i tng (1.17)

  • 51.1.6 Bi ton tng hp h thng

    Bi ton tng hp h thng l ton b qu trnh tnh ton, la chn b sung

    thm cc khu ph hp vo h thng. h thng khi hot ng t c nhng

    yu cu cht lng ra v sai lch, thi gian p ng qu .

    1.2 Phng php bm mc tiu truyn thng.

    1.2.1 Tho lun phng php iu khin truyn thng s dng thng tin, d liu ca tn hiu u ra ca i

    tng iu khin lm tn hiu u vo a ra tn hiu iu khin i tng.

    H thng ny c biu din bi cc phng trnh sau:

    ( ) ( ) ( ) ( ) ( )x t A t x t B t u t= +& (1.25) '( ) ( ) ( )y t C t x t= (1.26)

    Hnh 1.8 H thng iu khin c in

    1.2.2 B iu khin PID: (Proportional-Integral-Derivative) Tn gi PID l ch vit tt ca ba thnh phn c bn c trong b iu khin

    (hnh 1.10a) gm khu khuch i (P), khu tch phn (I), khu vi phn (D).

    sDT

    1

    IT s

    Hnh 1.10 iu khin vi b iu khin PID

    B iu khin PID c m t c dng tng qut sau.

    0

    1 ( )( ) [ ( ) ( ) ]t

    P DI

    de tu t k e t e d TT dt

    = + + (1.28) T m hnh vo ra tng qut ta c c hm truyn ca b iu khin PID

  • 61( ) [1 s]P DI

    R s k TT s

    = + + (1.29)

    1.2.3 Chn tham s PID ti u theo sai lch bm Bi ton c nhim v xc nh cc tham s ca b iu khin PI, gm kp, TI

    trong cng thc (1.29) hoc kp, TI, TD trong cng thc (1.31) sao cho tn hiu ra y(t)

    bm c vo hiu lnh (t) mt cch tt nht theo ngha.

    2 2( ) ( ) ( ) minQ t y t e t= = (1.32)

    V bi ton thit k b iu khin PID ti u tr thnh

    arg min ( )p f p = (1.34) 1.3. Phng php bm mc tiu hin i.

    1.3.1. Tho lun phng php. L thuyt iu khin hin i s dng m t khng gian trng thi trong min

    thi gian, mt m hnh ton hc ca mt h thng vt l nh l mt cm u vo, u

    ra v cc bin trng thi quan h vi phng trnh trng thi bc mt.

    Xut pht t quan im d trin khai l trng hp lut iu khin tuyn

    tnh, c cho bi:

    u(t) = K(x(t),t) (1.36)

    Hnh 1.12: M hnh phng php iu khin hin i.

  • 71.3.2. B quan st trng thi.

    B C

    A

    B C

    A

    L

    System

    u ++

    x& xy

    x&++

    Observer

    y

    x

    x

    Hnh 1.14 B quan st trng thi Luenberger bc y

    H thng trong hnh 1.14 c nh ngha bi:

    x Ax Bu= +& (1.38) y Cx= (1.39)

    1.3.3 iu chnh trng thi (LQR) (Linear Quadratic Regulator) Kho st vn duy tr trng thi ca h thng gi tr l 0, chng tc ng

    nhiu, ng thi vi cc tiu tiu hao nng lng 0, (0)x Ax Bu x x= + =& (1.43)

    y Cx=

    0

    1min ,2

    T TJ x Qx u Ru dt = + (1.44)

    Chn lut iu khin hi tip trng thi u = - Kx, K l hng s, thay vo biu

    thc ca J

    0

    1 ( )2

    T TJ x Q K RK xdt

    = + (1.45) 1.3.4 Gii thut thit k LQG (Linear Quadratic Gausian)

    Gi s phng trnh o lng ng ra c cho bi.

  • 8wx Ax Bu = + +& (1.57)

    y Cx v= + Gi s phng trnh hi tip c trng thi y .

    u = -Kx + r (1.58)

    Nu K c chn s dng phng trnh Riccati LQR v L c chn bi s

    dng phng trnh Riccati ca b lc Kalman. iu ny c gi l thit k LQG.

    iu quan trng ca cc kt qu ny l trng thi hi tip ca K v li ca b quan

    st L c th c thit k ring r.[4]

    1.3.5 M t b c lng trng thi gim bc Cho mt h ng hc S tuyn tnh bc n m t bi

    (S) n n n n nx A x B u= +& (1.62) n n ny C x= Vi , bc ca phn ng thi iu khin v quan st c ca S, cc

    vector v ma trn c kch thc ph hp.

    Hy xc nh b nh gi trng thi (SE) bc e,

    (SE) e e e e ex A x B u= +& (1.63) e e ey C x=

    1.3.6 Gim bc phn t iu khin Cc bi ton lin quan n phn t iu khin da vo tn hiu phn hi lm

    c s ra chin lc iu khin v cn phi x l trong khu khp kn. T v tr

    xut pht ca tn hiu phn hi m trong l thuyt h thng chia ra thnh iu khin

    truyn thng v iu khin hin i

    1.4. Vai tr ca b lc Kalman

    1.4.1 t vn . Phng trnh trng thi ca i tng

    wx Ax Bu = + +& (1.72) y Cx v= + (1.73)

  • 9

    x&

    x& x

    x

    y

    Hnh1.15 B quan st trng thi ca Kalman

    Phng trnh trng thi ca khu lc Kalman:

    ( ) x Ax Bu L y yy Cx= + + =

    & (1.74)

    Mc tiu ca thit k b lc Kalman l tm li c lng L c s c lng ti

    u trong s hin din ca nhiu w(t) v v(t)

    Sai s c lng:

    ( ) ( ) ( )x t x t x t= (1.75) 1.4.2 M hnh ton hc.

    1.4.3 Qu trnh c lng trng thi. Qu trnh c lng s dng phng php mch lc Kalman trong gim st bm mc

    tiu dc chia thnh hai giai on.

  • 10

    1k x F x

    =

    1T

    k kP FP F Q

    = +

    1T Tk k kK P H ( HP H R )

    = +k k k k k x x K ( z Hx )

    = +

    1k k kP ( K H )P=

    Thc cht ca gii thut Kalman tuyn tnh l mt phng php c tnh

    quy tuyn tnh cho php c lng trng thi ca mt h thng c nhiu sao cho

    lch gia gi tr c lng v gi tr thc t l b nht.

    1.4.4 Vai tr ca b lc Kalman Lc Kalman nhm c lng gi tr ch thc ca mt ci g , bng cch d

    on gi tr ca n v tnh tin cy (hay bt nh) ca d on , ng thi o

    c gi tr (nhng b sai s v c cc nhiu), sau ly mt trung bnh c trng gia

    gi tr d on v gi tr o c c, lm gi tr c lng. C th coi n l mt

    trng hp ca suy din c iu kin kiu bayes Cc thuc tnh c bn ca b

    lc Kalman c bt ngun t cc yu cu ca c lng trng thi.

    1.5 Kt lun chng Trong chng ny lun vn nu ra c cc khi nim c bn v bi ton bm

    mc tiu, trn nhng khi nim c bn nu ra c phng php bm mc tiu

    truyn thng, phng php bm mc tiu hin i. T tm ra vai tr ca b lc

    Kalman trong bi ton bm mc tiu.

  • 11

    CHNG II: S DNG B LC KALMAN

    TRONG BI TON BM MC TIU 2.1. Cc bin th ca b lc Kalman

    2.1.1. Nguyn tc c bn Trong ng dng gim st, bm mc tiu di ng, mch lc Kalman l qu trnh lp i

    lp li bc d on v hiu chnh trng thi ca h thng [13]. Xt mt h thng i

    din bi mt khng gian trng thi nh phng trnh (2.1) v (2.2).

    xk = Fxk-1 + vk (2.1) zk = Hxk + ek (2.2)

    2.1.2. Mch lc Kalman tuyn tnh Mch lc Kalman tuyn tnh a ra mt c lng ti u cho trng thi k -tip s

    dng cng thc tuyn tnh, gi s cc bin c phn b xc sut Gaussian.

    - Gi tr trung bnh cho trng thi k tip:

    1 k kx Fx = (2.3) - Hip phng sai ca c lng k tip:

    1 Tk kP FP F Q = + (2.4) - Tnh ton li mch lc Kalman:

    1( )T Tk k kK P H HP H R = + (2.5) - Gi tr hiu chnh trung bnh:

    ( )k k k k kx x K z Hx = + (2.6) - Hiu chnh hip phng sai:

    ( )k k kP I K H P= (2.7) 2.1.3. Mch lc Kalman m rng B lc Kalman m rng thc hin theo cc bc c lng

    - Gi tr trung bnh cho trng thi k tip:

    1 k kx x = (2.8) - Hip phng sai ca c lng k tip:

    1k kP P Q = + (2.9)

  • 12- Tnh ton li mch lc Kalman:

    1( )k k kK P P R = + (2.10) - Gi tr hiu chnh trung bnh:

    ( )k k k k kx x K z x = + (2.11) - Hiu chnh hip phng sai:

    ( )k k kP I K P= (2.12) 2.1.4. Mch lc Unscented Kalman

    Nguyn tc c bn ca Unscented Kalman l bin i Unscent. V c bn, y l mt

    phng php tnh ton thng k mt bin ngu nhin sau khi bin i khng tuyn

    tnh. Cho bin ngu nhin n chiu: xk-1 vi gi tr trung bnh $ 1kx v ma trn hip

    phng sai Pk-1

    Mch lc Unscented Kalman m t trng thi vi mt tp hp ti thiu cc im

    (sigma) mu c chn lc cn thn. 2n+1 im sigma c chn xung quanh c

    lng trc , vi n l kch thc ca khng gian trng thi. Sau mt trng s

    xc sut c gn cho nhng im sigma. Tip theo, cc im sigma ny bin i

    bng cch s dng bin i Unscent a ra mt c lng mi cho bin trng thi.

    Bin trng thi sau c hiu chnh bng cch bin i cc im sigma thng qua

    cc m hnh o lng tnh ton li Kalman. Cui cng, c lng c hiu

    chnh s dng li Kalman

    2.2. Lc Kalman trong bi ton bm mc tiu theo phng php

    phn on.

    2.2.1. Tho lun bi ton.

    2.2.2 M hnh bi ton. u vo l mt chui cc khung hnh, gi nh rng khng c s thay i v

    cng nh sng v khng c hin tng che khut. Ta c th vit nh sau:

    yk(x) = yk-1(x dk(x)) ( 2.35) M hnh quan st cho khung hnh th k tr thnh.

    gk(x) = yk(x) + nk(x) ( 2.36)

  • 13 Cn phi c lng phn phi xc xut c iu kin kt hp ca trng vecter

    chuyn ng dk, trng phn on cng sk, v trng phn on i tng (hay

    video) zk. Dng lut Bayes ta c:

    ( ) ( )( )1 11 1 1 1, , , ,

    , , , ,, ,

    k k k k kk k k k k k

    k k k

    p d s g g gp d s z g g g

    p g g g +

    + +

    = (2.37)

    M hnh mng Bayes th hin s tng tc gia 1 1, , , , ,k k k k k kd s z g g g +

    gk

    sk

    dk zk

    gk-1, gk+1

    Hnh 2.1 M hnh mng Bayes cho bi ton phn on video

    2.3 Bm mc tiu theo quy trnh ng thi. Trong phn ny cp h thng gim st mc tiu 3D nh hnh 2.2 H thng gim

    st mc tiu, mc tiu theo di l ngi di chuyn trc ng knh camera, thu nh,

    lu thnh file .avi v a vo h thng nhn dng v theo vt s dng tng mch lc

    Kalman bm theo i tng cn theo di.

    Hnh 2.2. H thng bm mc tiu

    M t h thng:

    S h thng gim st mc tiu hnh 2.2. H thng gm tn hiu vo v b phn

    pht hin, bm mc tiu v a ra kt qu hin th.

  • 14

    Hnh 2.3. S nhn dng nh

    B lc Kalman c coi nh b c lng trng thi h thng, c cu trc lc n

    gin v hi t tt cng vi kh nng lc nhiu cao [9]. M hnh cn c c

    lng d bo c m t bi h phng trnh trng thi :

    xk = Fxk-1 + vk

    zk = Hxk + ek Vector trng thi xk=[x, y, vx , vy], vector o lng zk = [x, y]T, ng vi ta v vn

    tc ca nh i tng trn mt phng nh thi im k. vk, ek l vector nhiu trong

    qu trnh chuyn ng v sai s php o.

    2.4. Kt lun chng Trong chng ny lun vn nu tng v cc bin th ca b lc Kalman ng dng

    thut ton mch lc Kalman trong bi ton bm mc tiu theo phng php phn

    on, bm mc tiu theo quy trnh ng thi. a ra gii php ng dng thut ton

    lc Kalman theo vt i tng, t file video thc hin tng b lc Kalman bm

    theo ngi di chuyn.

  • 15

    CHNG 3: V D MINH HO 3.1. Bi ton bm mc tiu

    3.1.1 t vn . Mt h thng bm mc tiu bng hnh nh l mt tp hp cc bi ton nh.

    u vo ca h thng s l hnh nh thu c ti cc im quan st.

    u ra ca h thng s l thng tin v chuyn ng ca cc i tng c

    gim st

    M hnh khi qut chung cho h thng bm mc tiu.

    Hnh 3.1 H thng bm mc tiu tng qut

    3.1.2 Bi ton pht hin i tng chuyn ng u vo ca bi ton pht hin i tng chuyn ng l cc khung hnh video

    thu c t cc im quan st, theo di. Nh vy c th gii quyt bi ton ny ta

    cn nghin cu mt s c im ca video.

    3.1.2.1 Cc khi nim c bn v video.

    3.1.2.2 Mt s thuc tnh c trng ca video

    3.1.3 Bi ton phn loi i tng

    3.1.3.1 Phn loi da trn hnh dng.

    3.1.3.2 Phn loi da trn chuyn ng.

    3.1.4 Bi ton theo vt i tng

    3.1.4.1 t vn

    u vo ca bi ton theo vt i tng l cc vt i tng, cc c trng ca

    i tng c pht hin thng qua khi x l pht hin i tng, phn loi i

    tng. Nh vy nhim v ca vn theo vt i tng l chnh xc ha s tng

  • 16ng ca cc vt i tng trong cc khung hnh lin tip t d on hng chuyn

    ng ca i tng.

    3.1.4.2 Cc vn gii quyt

    - Theo vt mc tiu da trn m hnh

    - Theo vt mc tiu da trn min.

    - Theo vt mc tiu da tn ng vin

    - Theo vt mc tiu da vo c trng

    * Chnh xc ho i tng tng ng (Object matching):

    * D on chuyn ng

    Nu gii quyt bi ton bm theo mc tiu t hiu qu v tin cy cao, c th ng

    dng trong rt nhiu lnh vc.

    3.2 Chng trnh m phng bm mc tiu

    3.2.1 Qa trnh thu nhn v nhn dng nh M hnh h thng Camera gim st mc tiu:

    Qu trnh ghi hnh c thc hin bng Webcam ca my Laptop thng qua chc nng h tr Image Acquistion ca phn mm matlab v lu li vi dng .avi hoc

    .mat. Sau s dng file ny input cho module nhn dng nh v bm theo vt mc

    tiu c thc hin bng b lc Kalman

    Chng trnh m phng qu trnh nhn dng v bm mc tiu thc hin theo lu

    hnh 3.6.

  • 17

    3.2.2. Bm mc tiu s dng thut ton Kalman Sau khi mc tiu c nhn dng, pht hin chuyn ng t rt trch c trng s

    c thut ton Kalman bm theo vt i tng thc hin theo lu hnh 3.7.

  • 18

    Rt trch c trng

    Kt thc

    Hin th

    N

    Y

    Hnh 3.7 Lu thut ton lc Kalman

    D on

    Tnh li Kalman

    Hiu chnh

    3.2.2.1 Thut ton mch lc Kalman tuyn tnh

    Bc d on:

    $ $ 1k kx F x

    = , (3.1) 1 Tk kP FP F Q = + .

    li Kalman: 1T T

    k k kK P H ( HP H R ) = + . (3.2)

    Bc hiu chnh:

    $ $ $k k kk kx x K ( z H x ) = + , (3.3)

    k k kP ( I K H )P= . 3.2.2.2 Thut ton mch lc Kalman m rng

  • 19 Bc d on:

    $ $ 1k kx x

    = , (3.4) 1k kP P Q = + .

    li Kalman: 1

    k k kK P ( P R ) = + . (3.5)

    Bc hiu chnh:

    $ $ $k k kk kx x K ( z x ) = + , (3.6)

    k k kP ( I K )P= . 3.2.2.3 Thut ton mch lc Unscented Kalman

    Bc d on:

    $ 20

    L ( m )k i k ii

    x W ( X )

    == , (3.7) $ $2

    0

    TL ( c )

    k kk i k i k iiP W ( X ) x ( X ) x

    =

    = . (3.8) Bin i Unscented:

    k i k i( Z ) h(( X ) )= , i = 0,...,2L (3.9) 2

    0k k

    TL ( c )

    k ki k i k iz z iP W ( Z ) z ( Z ) z R

    =

    = + $ $ $ $ , (3.10) $

    $20kk

    TL ( c )

    kki k i k ix z iP W ( X ) x ( X ) z

    =

    = $ $ , (3.11) li Kalman:

    $1

    k k kkk x z z zK P P= $ $ $ . (3.12)

    Bc hiu chnh:

    $ $ kk k k kx x K ( z z ) = + $ , (3.13)

    k k

    Tk k k kz z

    P P K P K= $ $ . (3.14)

    3.3 Kt qu thc nghim M phng mch lc Kalman bm mc tiu. Cc khung nh c ly ngu

    nhin l frame 72, 81, 93, 125 ca mt on video .avi khc nhau.

  • 20

    Frame 72

    Frame 81

    Frame 93

    Frame 125

    Hnh 3.8: Kt qu bm mc tiu

  • 21Gi tr o lng thc t ti v tr i tng c biu din bi mt hnh ch

    nht mu en trong khi mu xanh th hin cho d on v tr ca mc tiu. Ngoi ra

    kch thc ng bao c th hin qua nh xm nn en, bng nh m mu xanh

    bm theo ng bao.

    T hnh 3.5 cho thy mch lc Kalman c th d on v nh hng chnh

    xc cao. hnh ch nht mu xanh (d on) ph hp tng i chng kht vi hnh

    mu en (o lng). Mch lc Kalman c p ng nhanh. iu ny c ngha l khi

    i tng di chuyn th cho php o thay i t ngt.

    Kt qu m phng ca phng php bm mc tiu s dng mch lc Kalman,

    gi tr sai s c lng RMSE c tnh theo cng thc.

    ( )RMSE MSE GT ES= (3.15) 2

    1

    ( )n

    t

    GT EMSEn== (3.16)

    3.4 Kt lun chng

    Bi ton nghin cu mt s k thut pht hin v bm mc tiu, ng thi

    tin hnh x l cho ra kt qu l i tng ang cn theo vt ang v tr no

    nh du. Sau khi xc nh v tr i tng, s tip tc iu khin thit b ti v tr

    mong mun (v tr ca i tng ang theo vt), ng thi quyt nh ra s kin

  • 22

    KT LUN V HNG PHT TRIN 1. Kt lun.

    * V mt l thuyt.

    Lun vn nu ln tng quan v bm mc tiu, cc khi nim lin quan n

    x l hnh nh trong bm mc tiu, phn tch cc loi nhiu trng thi v m hnh nh

    hng n qu trnh theo di mc tiu di chuyn. Cc phng php bm mc tiu

    nh So khp mu, dng quang, Meanshift, Camshift, tr nh nn, lc Particle, c

    lng Kalman. Mi phng php c nhng im mnh v hn ch khc nhau. Tuy

    nhin mch lc Kalman vn l la chn ti u cho qu trnh bm mc tiu xut pht

    t cc u nhc im ca n.

    * V mt thc tin.

    Lun vn a ra hng tip cn ng dng mch lc Kalman trong bi ton

    bm mc tiu c th nh s dng phng php nhn dng hnh nh ca phng php

    tr nh nn, trch chn c trng, s dng thut ton mch lc Kalman bm mc

    tiu chuyn ng. a ra kt qu m phng, nh gi kt qu sai s c lng v o

    c.

    2. Hng pht trin Trong qu trnh thc hin ti, do nhng hn ch v trnh v thi gian

    thc hin ti, chng trnh c xy dng ch l cc thut ton pht hin chuyn

    ng v theo vt mc tiu da vo video. trin khai trong thc t n i hi cn

    phi ci tin hn na. Hy vng trong tng lai, nhng pht trin di y s gip

    ti hon thin hn.

    - Kt hp vic pht hin khun mt vi vic pht hin mt, pht hin hnh dng

    ca con ngi.

    - Xy dng c thut ton ci thin cht lng ca video nh loi tr nhiu,

    loi tr bong v ti u ha cc thut ton tng tc ca chng trnh.

    - Nghin cu mch lc Unscented Kalman phi tuyn cn chnh h thng v

    tinh.