Indonesian J
ournal of Ele
c
trical Engin
eering and
Computer Sci
e
nce
Vol. 2, No. 3,
Jun
e
201
6, pp. 592 ~ 60
6
DOI: 10.115
9
1
/ijeecs.v2.i3.pp59
2-6
0
6
592
Re
cei
v
ed Fe
brua
ry 28, 20
16; Re
vised
April 22, 201
6; Acce
pted
May 9, 201
6
Dual DC Motor Speed Control Based on Two
Independent Digital PWM Signals using
PIC16F877A Microcontroller
A
y
man Y
Yousef
1*
, MH Mostafa
2
1
Electrical Engineer
ing Dept., Facu
lt
y
of Engineer
ing at
Shoubra, Benha Universit
y
, Cairo, Egy
p
t
2
Distributio
n S
e
ctors, Sout
h Cairo El
ectrica
l
Distributi
on C
o
., Cairo, Eg
yp
t
*Corres
p
o
ndi
n
g
author, e-ma
i
l
: A
y
man.
yo
uss
e
f@feng.b
u
.ed
u
.eg
A
b
st
r
a
ct
In this p
aper
a
dua
l o
pen
lo
o
p
spe
ed c
ontro
l
system bas
ed
on tw
o in
de
pe
nde
nt PWM signa
ls o
f
sma
ll p
e
rman
ent magn
et DC (PM
DC) motors usin
g PIC16F
87
7A mi
crocontro
ller (
M
CU) has b
e
e
n
desi
gne
d a
n
d
i
m
p
l
e
m
e
n
ted. T
he C
aptur
e/Co
mp
are/PW
M (
CCP)
mo
dul
es
of the MC
U a
r
e confi
gur
ed
as
PW
M mod
e
an
d the MCU is
p
r
ogra
m
me
d usi
ng flow
cod
e
so
ftw
are package
to gener
ate tw
o PW
M signa
ls
w
i
th various
du
ty cycles at the
same freq
uen
cy. A dual
H-br
idg
e
cha
n
n
e
l c
h
ip S
N
75
44
10
is use
d
to driv
e
the
motors. T
h
e vari
atio
n of
PW
M duty cyc
les is
rel
a
te
d
directly t
o
co
ntrolli
ng
the
DC
motors ter
m
i
n
a
l
voltag
e w
h
ich directly pr
oport
i
on
al w
i
th spe
ed of
each
mo
tor. The comp
l
e
te
PWM control system
mo
de
l
has be
en si
mulate
d usi
ng p
r
oteus des
ig
n suite so
ftw
are packag
e
. T
h
e
devel
op
ment of hardw
are a
n
d
softw
are of the dual D
C
motor
speed co
ntrol
system h
a
s be
en exp
l
ai
ne
d a
nd clar
ified.
Ke
y
w
ords
: PIC16F
8
77A, PW
M, CCP1, CCP2, and PMD
C
Copy
right
©
2016 In
stitu
t
e o
f
Ad
van
ced
En
g
i
n
eerin
g and
Scien
ce. All
rig
h
t
s reser
ve
d
.
1. Introduc
tion
Direct current
(DC) motors pl
ays an ef
fective role
and still
found
in several industri
a
l
appli
c
ation
s
such a
s
toys, disk drive
s
, steel ro
llin
g mills, pape
r ma
chine
s
and in
conj
un
ction with
power el
ectro
n
ic devi
c
e
s
[1]. The DC
motors ha
s
many goo
d chara
c
te
risti
c
s in addition,
high
reliability, flexibility which
make its
sp
eed contro
l i
s
very simpl
e
and suit different ope
ra
ting
con
d
ition
s
. It co
nvert
s
el
e
c
tri
c
al
p
o
wer into m
e
chan
ical
po
wer th
roug
h m
u
tual
effect b
e
twe
en
two
ma
gnet
fi
elds. One of these
two ma
gnet
fiel
d
s
i
s
often produ
ced by p
e
rm
a
nent ma
gnet
in
stator el
emen
t [2]. The oth
e
r mag
netic fi
eld is
p
r
odu
ced by elect
r
ic current pa
ssi
ng throu
gh th
e
rotor (a
rmatu
r
e) wi
nding.
This
mutual
intera
cti
on
bet
wee
n
the t
w
o
fields produ
ces to
rqu
e
le
a
d
s
to the rotor rotation.
The speed of
DC moto
r ca
n be co
ntrolle
d by two maj
o
r metho
d
s, the first is a m
agneti
c
field cont
rol t
h
is meth
od i
s
u
s
ed in
se
parately ex
cited DC moto
rs an
d ca
nnot
be used
with
perm
ane
nt magnet moto
rs [3]. The second is a
r
matu
re voltage co
ntrol. In this work, the second
method is u
s
ed becau
se the cho
s
e
n
motor is pe
rma
nent magn
ets DC mot
o
r (PMDC). The
s
e
motors a
r
e u
s
ed i
n
ap
plications th
at re
quire
co
mpa
c
t size
and
fra
c
tional
horse
power
whe
r
e
they
are m
anufa
c
t
u
red
at low
cost. The
r
e a
r
e seve
ral te
chniqu
es
of DC moto
r spee
d co
ntrol u
s
e
d
in
many practi
cal co
ntroll
er
appli
c
ation
s
su
ch a
s
by u
s
ing thy
r
isto
r,
ch
oppe
r
circuit, Fuzzy Lo
gic
Controlle
r an
d digital co
ntrollers [4]. In
mode
rn
spee
d appli
c
ation
s
the digital control te
chniq
u
e
s
provide a b
e
tter way to re
al
ize the DC m
o
tor sp
eed
co
ntrol [5].
The main p
u
r
po
se of the
pre
s
ent work
is to desig
n
and implem
ent the hard
w
are and
softwa
r
e
of o
pen l
oop
digit
a
l control
system ba
se
d o
n
PWM
to
cont
rol
dual
DC
Motor
usi
ng
PIC
16F87
7A microcontroller.
2. Modeling of PMDC Mo
tor
The equival
e
nt circuit sho
w
n in Figu
re
1 rep
r
e
s
ent
s a perm
ane
nt magnet DC
motor.
Evaluation Warning : The document was created with Spire.PDF for Python.
ISSN: 25
02-4
752
IJEECS
Vol.
2, No. 3, Jun
e
2016 : 592
– 606
593
Figure 1. Modeling of PM
DC moto
r
Whe
n
the
su
pply voltage
i
s
a
pplie
d to t
he terminal
s
of a PM
DC
motor, the
a
r
mature
cur
r
e
n
t
of
i
a
flows in the
armatu
re
circuit, and the indu
ced b
a
ck emf and a
motor torque
is
develop
ed to balan
ce the l
oad torq
ue at
a certai
n
spe
ed. The termi
nal voltage is
given by:
b
a
a
a
a
e
dt
di
L
R
i
V
(1)
The ba
ck e
m
f is given by:
m
b
b
k
e
(2)
Then:
b
a
a
a
k
R
i
V
(3)
a
t
m
i
k
T
(4)
m
d
m
m
B
T
T
dt
d
J
(5)
Whe
r
e:
2
60
n
(6)
Whe
r
e V
a
is terminal vol
t
age in volt, ia is ar
m
a
ture
curre
n
t in amp, L is armatu
re
indu
ctan
ce in
henn
ery, e
b
back
emf of
motor in volt, R
a
is
arm
a
ture re
si
stan
ce i
n
omh, di
a
/dt
is
rate
of chang
e of a
r
matu
re
cu
rrent in
a
m
p/se
c,
ω
m
i
s
m
o
tor
sp
ee
d in
rad/
se
c,
n i
s
m
o
tor
speed
in r.p.m, Tm
is motor torque in
Nm,
k
t
i
s
torque
co
nstant. Then, th
e
sp
eed
control expression
of
dc moto
r is gi
ven as,
b
a
a
a
b
b
k
R
i
V
k
e
(7)
In perma
nent
magnet
DC
motor, the on
ly met
hod u
s
ed to sp
eed
control i
s
the a
r
mature
voltage co
ntrol method, b
e
ca
use the p
r
oviding
m
a
g
netic field by
the perma
n
ent magnet
s is
con
s
tant a
n
d
can
not alte
red. Refe
rri
ng
to Equation
7, it is foun
d
that t
he spee
d of the m
o
to
r is
prop
ortio
nal t
o
the a
r
matu
re voltag
e, th
en by
cont
rol
ling this volta
ge the
motor sp
eed
ca
n b
e
controlled.
Evaluation Warning : The document was created with Spire.PDF for Python.
IJEECS
ISSN:
2502-4
752
Dual
DC Mot
o
r Spee
d Co
ntrol Based o
n
Two Inde
pe
ndent Di
gital PWM …
(A
ym
an Y Yousef)
594
3. Pulse Width Modula
t
io
n (PWM
)
The Pulse
wi
dth modulatio
n techniq
ue i
s
the
simple
st and most efficient way for spe
ed
control of
DC motor [6]. It con
s
id
ere
d
a
s
on
e of the v
a
riou
s m
e
tho
d
s u
s
e
d
to
co
ntrol d
c
mot
o
r by
gene
rate an
a
l
og voltage u
s
ing di
gital si
gnal
s. It used
also in ma
ny application
s
su
ch a
s
co
ntrol
of delivered
p
o
we
r to
a l
o
a
d
, gen
eratio
n
of
sine
wave
forms,
and
a
nalog
voltage
level g
ene
rat
i
on
[7]. The PWM Taniqu
e d
epen
ds o
n
d
e
riving the d
c
motor by p
u
lse
d
wavefo
rm (su
c
cessi
v
e
pulses) with “ON-OFF
”
logi
c situatio
ns a
s
sh
own in Figure 2.
Figure 2. Pulse wi
dth mod
u
lation techni
que
In this meth
o
d
, the avera
g
e
value of th
e motor
appli
ed voltage i
s
cha
nge
d by
varying
the pulse
wid
t
h of the driving sign
al. Co
nse
que
ntly, the motor spe
ed can b
e
varied by cha
n
g
i
ng
the ratio
bet
ween th
e p
u
lse
width
or the
ON time
T
on
and peri
od
ti
me
T
period
of the a
pplied
si
gnal
whi
c
h is
calle
d duty cycle a
nd given by:
Time
Period
width
Pulse
cycle
Duty
(8)
period
ON
T
T
cycle
Duty
(9)
Then, the dut
y cycle ca
n b
e
defined a
s
the fra
c
tion of time perio
d for whi
c
h the
si
gnal is
ON to total time peri
od [8]. The avera
g
e
value of the motor ap
plied
voltage V
av
is given by:
T
m
period
ON
rated
av
V
T
T
dt
t
V
T
V
0
)
(
1
(10
)
m
av
V
cycle
Duty
V
(11
)
Whe
r
e: T
period
= T
ON
+ T
OFF
, Dut
y
cy
cle =
T
ON
/ T
pe
r
i
o
d
, and V
m
= ampli
t
ude of the motor
rated voltage.
The ave
r
ag
e power a
nd re
spe
c
tively the
spe
ed of d
c
motor
can
be
varied by
ch
angin
g
the duty cycl
e of the si
gna
l whi
c
h i
s
call
ed pul
se
widt
h modul
ation
PWM. In this
control meth
o
d
,
the po
we
r in
put to the
m
o
tor i
s
swit
ch
ed on
an
d of
f quickly with
high
switchi
ng rate
whi
c
h is
enou
gh to ma
ke the switchi
ng effects a
r
e
negligible a
n
d
unnoti
c
ed.
3. Microcontroller PWM Gener
a
tion
Techniqu
e
The g
ene
rati
on of P
W
M u
s
ing PI
C16F
8
77A MCU
de
pend
s o
n
its
built in
CCP
module
s
whi
c
h a
r
e
m
ean
s
Captu
r
e/Comp
are/PWM. Th
e PIC16F
877A
M
C
U ha
s two
(CCP)
Modul
es,
CCP1
an
d CCP2 at pi
ns
RC2 an
d RC1 of Port
C resp
ectively a
s
sho
w
n in
Figure 3. Ea
ch
module
(CCP1 and CCP
2
) contain
s
a
16 bit regi
ster
(two 8-bit regi
sters) [8].
The two P
W
M
regi
sters
CCPR1 a
nd
CCPR2
are b
e
long to
CCP1 and
CCP2 modul
es re
spe
c
tively. The
regi
ster CCP
R
1 i
s
co
nsi
s
t
s
of
CCPR1
L
(lo
w
byte) and
CCPR1
H
(high
byte
). Similarly, t
h
e
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ISSN: 25
02-4
752
IJEECS
Vol.
2, No. 3, Jun
e
2016 : 592
– 606
595
regi
ster CCP
R
2
ha
s
CCP
R2L
(lo
w
byte)
and
CCP
R
2
H
(high
b
y
te) [9]. The
CCP1CON
and
CCP2
C
O
N
registe
r
s
controls th
e o
p
e
r
a
t
ion of
CCP
1
and
CCP2
re
spe
c
tively. T
he
spe
c
ial
ev
ent
trigge
r is ge
n
e
rated by a
compa
r
e mat
c
h and will
re
set Timer1 a
n
d
start an A/
D co
nversion
(
i
f
the A/D mo
d
u
le is en
able
d
)[10]. Th
e b
l
ock di
a
g
ram
of the
CCP
1 and
CCP2
modul
es
an
d its
asso
ciated re
gisters is
sho
w
n Figu
re 4.
Figure 3. Microco
n
trolle
r Pic16F
877A pi
n
assignm
ent.
Figure 4. CCP module
s
asso
ciated regi
sters.
These t
w
o
m
odule
s
ca
n b
e
configu
r
ed
t
o
ge
ne
rate t
w
o sepa
rate
a
nd in
dep
end
e
n
t PWM
sign
als
with
different duty
cycle. Th
e two PW
M fre
quen
cie
s
is t
he sa
me for
CCP1
and
CCP2
becau
se it use Time
r2 a
s
a time base
.
More
detail
s
abo
ut the operation of
CCP mo
dule
s
in
PWM mode a
nd timer re
so
urces a
r
e fou
nd in [8] [9]
[1
0]. The PWM function
al blo
c
ks is
sho
w
n
in
Figure 5 and
the corre
s
p
o
n
d
ing PWM
waveform timin
g
can b
e
se
e
n
in Figure 6 [11].
Figure 5. PWM module bl
o
ck di
agram
Figure 6. PWM waveform
sho
w
in
g peri
od and
dut
y
cy
cle
The
duty cy
cle an
d p
e
rio
d
definitio
ns
are
cle
a
r fro
m
the fig
u
re
(6
) itself. T
he P
W
M
Period, Duty Cycle a
nd Re
solutio
n
are
calcul
ated by these formul
a
s
[9]:
Period
= [(PR2) + 1] × 4
× Tosc × (TMR2 Prescal
e
Value)
(12
)
Duty Cycle
= (CCPR1L:CCP1CO
N
<5:4>) ×
To
sc
× (T
MR2 P
r
e
s
cal
e
v
a
lue)
(13
)
Res
o
lution =
[log (FOS
C /FPWM)] / [log(2)] bits
(14)
Evaluation Warning : The document was created with Spire.PDF for Python.
IJEECS
ISSN:
2502-4
752
Dual
DC Mot
o
r Spee
d Co
ntrol Based o
n
Two Inde
pe
ndent Di
gital PWM …
(A
ym
an Y Yousef)
596
4. Dual DC Motor Driv
er a
nd Control Strateg
y
The SN75
44
10 driver
chip
shown in Fig
u
re 7 whi
c
h i
s
the quad Hal
f
-H-B
ridg
e ch
annel is
cho
s
e
n
to dri
v
e the dc motors in two direction
s
an
d p
r
ovide them b
y
sufficient cu
rre
nt. It can be
driving hi
gh voltage moto
rs (from 4.5V
to 36V) u
s
ing
TTL logi
c le
vels +5V and
sup
p
ly enou
gh
contin
uou
s o
u
tput cu
rrent
up to
1A [12].
The pi
n a
ssi
gnment
s a
nd
con
n
e
c
tion d
e
scriptio
n of t
he
SN754
410 d
r
i
v
er chip
whe
n
it used to drive t
he two DC motors is
shown in Figu
re 8.
Figure 7. SN7544
10 drive
r
chip
Figure 8. SN7544
10 Pin a
ssi
gnme
n
ts a
nd co
nne
ctio
n diagram
The SN754
4
10 chip h
a
s t
w
o
control in
puts, on
e en
able in
put an
d one
output
per e
a
ch
cha
nnel. The
pins 1,2E
N, 1A, 2A, 1Y an
d 2Y contro
l the first moto
r on the left sid
e
while the pi
ns
3,4EN, 3A, 4A, 3Y and 4Y control the o
t
her moto
r o
n
the right side
. The Control
inputs (1A, 2
A
)
and (3A, 4A) are
u
s
ed
to control
the rot
a
tion
di
re
ct
io
n
(clo
ckwi
se
or anti clo
c
kwise)
for
the first
motor a
nd
se
con
d
respe
c
tively. The ena
ble inp
u
ts
(1,
2
EN a
nd 3,4
E
N) a
r
e
used
to turn th
e t
w
o
H-b
r
id
ge O
N
or OFF. T
he
pins V
CC1
an
d V
CC2
are used to p
o
wer the driver
ch
ip as follo
w: pin
V
CC1
is use
d
t
o
po
we
r the l
ogic
gate
s
in
side th
e
chip
by (+5V) lo
gi
c supply volta
ge an
d pin
V
CC2
is u
s
e
d
to p
o
w
er the m
o
to
rs
by their rated volt
age
s
a
nd thi
s
pin
ca
n re
ceive
up
to 36V. T
he pi
ns
4,5,13, and
1
2
must
be
co
nne
cted to th
e gro
und
(0V
)
and
used a
s
a h
eat si
nk. The propo
sed
control st
rate
gy based o
n
PWM te
chniqu
e by
g
enerating two indep
end
e
n
t sign
als u
s
ing
PIC16F8
77A microcontroll
er and the S
N
75
441
0 driv
er chi
p
is sho
w
n in Figu
re
9.
Figure 9. Pro
posed PWM
control strate
gy
The dual con
t
rol strate
gy depe
nding u
p
on the oper
ation of the H-Bridge is fairl
y
simple
by identifying
the logi
c stat
e (High
or L
o
w
)
of t
he en
a
b
le an
d inp
u
t pins. T
he lo
gic state
of the
s
e
control pin
s
i
s
dete
r
min
e
d
by mean
s of
the logi
c val
ues
se
nt fro
m
micro
c
ontroller [8]. Ta
ble 1
sho
w
the be
h
a
vior of the two DC moto
r for different in
put con
d
ition
s
.
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Table 1. DC Motors beh
aviour with diffe
rent input con
d
itions
Enable
1,2EN
3,4EN
Inputs
1A, 3A
Inputs
2A, 4A
DC motor
1
and
DC motor
2
Functions
1
1
0
Runs counter clockw
ise (left direction)
1
0
1
Runs counter clockw
ise (right dir
e
ction)
1
1
1
Fast Motor Stop
or brake
1
0
0
Fast Motor Stop
or brake
0
Regardless
Regardless
Fast Motor Stops
or brake
4. Dual DC motor driv
e
s
y
stem Desc
ription
The sche
mati
c diag
ram of
the prop
osed
dual DC motor sp
eed
con
t
rol is de
sign
ed and
simulate
d by
Proteus
7.10 de
sign
suite softwa
r
e packa
ge.
The main
element of
the
impleme
n
ted
control
syste
m
is the
PIC16F87
7A mi
crocontroller is use
d
with ot
her
ele
c
tric a
n
d
electroni
c de
vices a
s
sho
w
n in Figu
re
10.
Figure 10. Schematic di
ag
ram of the Du
al PW
M co
ntrol of DC moto
r desi
gne
d by Proteus
s
o
ftware
The mi
cro
c
on
troller read
th
e an
alog
valu
e of
th
e volta
ge a
c
ro
ss two vari
able
re
sistan
ce
s
(potentio
mete
rs) which a
r
e
con
n
e
c
ted
with two
ADC (A
N0
and
AN1)
at pin
s
(RA0
and
RA1).
The ch
ang
e in these an
alo
g
values of in
put
voltage will chang
e the
duty
cycle of the generate
d
PWM
sign
als whi
c
h
directl
y
linke
d to th
e DC m
o
tors sp
eed
s. A f
our fixed
spe
ed p
u
sh b
u
ttons
and th
e two
potentiomete
rs
can
be
varying the
s
p
e
ed of th
e t
w
o
DC m
o
tors
according
to
the
function of e
a
ch el
eme
n
t. The pote
n
tiometers give
broa
d ra
nge
of spee
d co
ntrol from
0
%
to
100% of the maximum mo
tor sp
eed. Th
e four pu
sh buttons can be
adju
s
ted manually
to give
more
fixed v
a
lue
s
of
sp
e
ed
whi
c
h u
s
e
d
u
s
ually
su
ch a
s
5
0
% an
d 10
0%. The
s
e fe
w val
u
e
s
of
fixed spee
d can be chan
ge
d in the future by
editing a
nd upd
ating the micro
c
ontroller p
r
og
ram
.
The motors d
r
iver chi
p
SC7544
10 is int
e
rfaced
with
PIC micro
c
o
n
t
roller pin
s
RC6, RE1,
RC4, a
nd
RC5 th
rou
gh t
he o
u
tputs IN1, IN2, IN3,
and
IN4
of t
w
o
dou
ble p
o
les rel
a
ys
(DP
relay1
and
DP relay2
)
at it
s in
put te
rmin
als A
1
, A2, A
3
, and
A4
re
spectively. Th
e two
pi
ns RC6
and RE1
are alway
s
at HI
GH
l
ogi
c state
but RC4
an
d RC5
a
r
e fo
rever at L
O
W logi
c
state. T
h
e
Enable pin
s
1,2EN an
d 3,4EN are co
n
necte
d to
the
gene
rated t
w
o PWM
sig
nals at pin
s
RC2
and
RC1. T
he o
u
tput pi
ns Y1, Y
2
,
Y3, and Y
4
of SN75
441
0
chi
p
, ea
ch t
w
o
of them
are
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IJEECS
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752
Dual
DC Mot
o
r Spee
d Co
ntrol Based o
n
Two Inde
pe
ndent Di
gital PWM …
(A
ym
an Y Yousef)
598
con
n
e
c
ted to
one of the two DC moto
rs re
sp
ec
tivel
y
. The two double p
o
le
s relays (DP rel
a
y1
and DP relay
2
) are used to reverse the
rotation dire
ction (clo
ckwi
se or anticl
o
ckwise) of the two
DC moto
rs when the pin
RC3 sen
d
si
gnal with Hi
g
h
logic state i
f
the directio
n swit
ch is tu
rned
on. A digital
LCD (4x16)
pins
are con
necte
d
to p
o
r
t B and
a 4
-
digit 7
-
Segm
ent multiplex
ed
displ
a
y unit p
i
ns a
r
e
con
n
e
cted to
port
D to di
splay the detail
s
of
DC m
o
tors
control m
ode
s o
f
operation. A 5V/12V DC p
o
we
r su
ppl
y consi
s
ts of AC step do
wn transfo
rme
r
22
0v/12v, full wave
rectifie
r bri
d
g
e
, voltage reg
u
lator, an
d rip
p
le filt
er wa
s i
m
pleme
n
ted [13]. PIC microco
n
trolle
r an
d
SN754
410
driver chi
p
are
sup
p
lied by 5
V
logic le
vel,
and the
DC
motors fed b
y
12V as a
ra
ted
voltage.
5. Soft
w
a
r
e
Algorithm Implementa
tion
The
softwa
r
e
impleme
n
tation an
d
cont
rol algo
rithm
of the impl
e
m
ented
dual
dc m
o
tor
control syste
m
wa
s devel
oped
u
s
ing F
l
owcod
e
software p
a
cka
g
e
. Flowco
de i
s
a
graphi
cal
tool
use
d
to prog
rammin
g
the
PIC micro
c
ontrolle
r o
n
ce dra
w
in
g th
e pro
g
ram flowcha
r
t [8]. The
flowchart of the PWM cont
rol algo
rithm i
s
sh
own in Figure 1
1
.
Figure 11. Flowcha
r
t of the
develop
ed control
algo
rit
h
m
The si
mulatio
n
of two mot
o
rs
ba
sed P
W
M
signal
s
usin
g flowco
de software
at medium
and maxim
u
m spe
e
d
s
wi
th duty cycle
equal
s 5
0
% and 1
00% resp
ectively, in two di
re
ction
s
(anticl
o
ckwise and cl
ockwi
s
e) u
s
in
g pu
sh bu
tton switches a
r
e sho
w
n in Figure 12
.
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752
IJEECS
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2, No. 3, Jun
e
2016 : 592
– 606
599
Figure 12a. T
w
o moto
rs at
starting
(PWM
module
s
CCP1 and CCP2
have
Dut
y
cy
cle
= 0)
Figure 12b. T
w
o moto
rs
ru
ns in anti
c
lo
ckwi
se
dire
ction (CCP1 and CCP2
module
s
at Duty
cycle e
qual 5
0
% and 100
% resp
ectivel
y
Figure 12
c. Two moto
rs
ru
ns in cl
ockwise dire
ction
(CCP1 an
d CCP2 mod
u
le
s at Duty cycle
equal
s 10
0% and 50% respectively)
Also the
sim
u
lation at very low , low, equal, hig
h
, and very hig
h
spe
e
d
s
in
different
dire
ction
s
wit
h
duty cycl
e
equal
s 1
0
%, 25%,
65%, 75% and
9
0
% usin
g po
tentiometers
are
sho
w
n in Fig
u
re 13.
Figure 13a. T
w
o moto
rs
ru
ns in anti
c
lo
ckwi
se
dire
ction (CCP1 and CCP2
module
s
at Duty
cycle e
qual 9
0
% and 10%
respe
c
tively)
Figure 13b. T
w
o moto
rs
ru
ns in cl
ockwise
dire
ction (CCP1 and CCP2
module
s
at Duty
cycle e
qual
s
25% and 75
% resp
ectivel
y
)
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IJEECS
ISSN:
2502-4
752
Dual
DC Mot
o
r Spee
d Co
ntrol Based o
n
Two Inde
pe
ndent Di
gital PWM …
(A
ym
an Y Yousef)
600
Figure 13
c. Two moto
rs
ru
ns in anti
c
lo
ckwi
se di
re
ctio
n at the equal
spee
d
(CCP1 an
d CCP2 mod
u
le
s at same Duty cycle equ
al 65%)
6. Hard
w
a
re
Setup and E
x
perimental Resul
t
s
6.1. Hard
w
a
r
e
implementation
The ha
rd
ware developm
e
n
t setup of the im
pleme
n
t
ed dual dc
motor control
system
(rate
d voltag
e V =
12V
and
rated
curre
n
t I =
0.5A) control
system
usi
ng
PIC1
6F8
77A
microcontroll
er ba
sed o
n
two ind
epen
d
ent PWM sig
nals i
s
sh
own
in Figure 1
4
.
Figure 14. Photogra
ph of h
a
rd
wa
re setu
p con
n
e
c
tion
of PIC16F87
7A MCU
based du
al DC motor P
W
M control system
6.2. Simulati
on Results
The si
mulatio
n
re
sults
of the gen
erated
PW
M sig
nal
s wa
s a
c
com
p
lish
ed with
perio
d of
4ms an
d fre
quen
cy of 244 Hz u
s
ing
proteu
s
suite
software pa
ckage. The
output two PWM
sign
als
of the
two mo
dule
s
CCP1
and
CCP2 at pin
s
RC2 an
d RC1 for different
values
of du
ty
cycle a
r
e sho
w
n in Figu
re
15. The sam
e
duty
cycle values of 5%
, 25%, 50%,
75%, and 10
0%
wa
s
cho
s
en
for the
two
PWM
sign
als i
n
orde
r to
rot
a
te the t
w
o
motor
at the
same
spee
d. The
oscillo
scope
uppe
r tra
c
e is PWM1 si
gna
l while the lo
wer trace is P
W
M2
sign
al a
nd Ho
rizontal
: 1
ms
ec
/div. Vertic
al; 2 volt/div.
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IJEECS
Vol.
2, No. 3, Jun
e
2016 : 592
– 606
601
Figure 15a. O
u
tput two PWM signal
s at duty
c
y
c
l
e 5%. (The two motors
rotates
at the s
a
me
very low sp
ee
d)
Figure 15b. O
u
tput two PWM signal
s at duty
c
y
c
l
e 25%. (The two motors
rotates
at the
same lo
w spe
ed)
Figure 15
c. Output two PWM signal
s at duty
c
y
c
l
e 50%. (The two motors
rotates
at the
same M
ediu
m
spee
d)
Figure 15d. O
u
tput two PWM signal
s at duty
c
y
c
l
e 75%. (The two motors
rotates
at the
same ve
ry high sp
eed
)
Figure 15e. O
u
tput two PWM
signal
s at duty cycle 10
0%.
(The two mot
o
rs
rotates
at the s
a
me Maximum s
p
eed)
The sim
u
latio
n
of the outp
u
t two PWM
sign
als a
nd the co
rrespon
ding termi
nal
voltages
of the two
DC moto
rs for
variou
s valu
e
s
of d
u
ty cycl
e with
oscillo
scope
(Hori
z
ontal: 2 m
s
e
c
/div.
Vertical; 5 vol
t/div) are sh
o
w
n in Figu
re
16.
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