Simulation of speed control DC motor by using DSP board
for Electrical Engineering Education
Santi Wangnipparnto1 and Satean Tunyasrirut2
1

Department of Electrical Engineering, 2Department of Instrumentation and Control Engineering
Pathumwan Institute of Technology, Thailand
3. Experimental results

1. Introduction
A DC motor is a direct current (DC) electric motor that used torun machinery. DC motors are found in many applications as small
as toys and disk drives, or in large sizes to operate steel rollingmills and paper machines. The speed of the D.C. motor isdependent and directly proportional is to this variable voltage. The
speed encoder or tachometer senses the actual speed of motor inrpm and converts it to a feedback signal proportional to shaft
speed. This signal closes the speed-control loop. The feedback is
compared with reference setpoint and fed to the differential error
amplifier, ad infinitum. Motor speed will remain constant until thespeed setpoint changes. In this research, DC motor 24 volt, 48
watt, and base speed 400 -1600 rpm is used for control its speed.
Matlab / Simulink software, the interface card dSPACE DS1104
DSP board, PI controller method are used for communication
signal and made the controller. The unload and load conditions areconsidered for performance of speed control in this work.
2. Experimental setup
Block diagram and DC motor circuit can be shown in Fig.1and Fig.2 respectively.
Computer(dSPACE DS1104)

D/A

Power Amplifier

DC motor system

Speed and current
SensorA/DRavinLa

sw1
Ia (t)

vmebT, ωsw2
GM

400

300
230 rpm
200145 rpm
1000-10002

T=179s

The equations are set, institute parameters on its, and get
transfer function model as(1)68101214161820Fig. 3. Example of open loop test at step setpointfrom 0-465 rpm.
Open loop test at various step setpoint from 0-465 rpm to 01163 rpm are used for find average gain (Kp) and Time constant(T) as shown in Fig. 3 and found that the average Kp and T are
0.767 and 1.58 respectively. Pole displacement method is usedfor set the parameters Kc and Ti where we assumed the dampingvalue( ζ )equal 0.707 and various the frequency ( ω ), theresults as shown in table 1. The simulink and Controldesk ofmatlab are used for test the simulation and made the display for
set the parameters on its as shown in Fig.4. At condition testing,speed step 800 to 1200 rpm, Kc=3.06 s, Ti=0.661, no load andfull load are considered. The result of its can be shown as Fig.5
and table 2.

sw3

φKp

T

φKc

Ti

0.707

0.767

1.58

0.559

0.324

0.504

0.707

0.767

1.58

11.609

0.781

0.707

0.767

1.58

1.5

3.065

0.661

Table 2. Performance of control motor when various load at
speed step 800-1200rpm and speed setpoint 1200 rpm
overshoot overshootFig. 2. DC motor and load on its circuit.

ω ( s)
2.97=Vm ( s) s 2 + 400 s + 127.87

4Table 1. The results of Kc and Ti when various ω

Fig. 1. Block diagram of DC motor speed control.
KA500465 rpm

speed

rise timespeed

steady state

speedTime toerror

decrease decrease

speed

setpoint

load

(rpm)

(%)

(sec)

(%)

(rpm)

(%)

(sec)

(status)

1262

5.17

0.771

0-

--

no lo ad

1255

4.58

0.788

0-

--

half load

1247

3.920.81901076

10.33

5.05

full load

1) DC motor speed control system with the interface carddSPACE DS1104 can be controlled by the speed at around 100 2000rpm.
2) Influence of ω at the high load, the value of rising time(Tr)ishighbut
notmore
than2seconds.
3) When the system load increases, the rising time is increasing
too
but
theovershoot
speed
will
decline.
4) When the motor run at a constant speed and interrupt load,
the motor speed decreases and adjust their speed to the target inless than 2 seconds.

a.)Acknowledgements
The Authors gratefully acknowledge the Mr. Channarong
Chomchalam and Mr. Uthai Wongkhuenkaew who built andtesting the experimental apparatus.
Referencesb.)
Fig. 4. PI controller by Matlab/Simulink andfor set parameters.
Rpm
1800
1700

ω =0.559

ω =1.500

ω =1.000

1600
1500
1400
1300
1200
1100
1000
01020304050

60708090 Second7080 Seconda.)
Rpm
1800
1700

ω =0.559

ω =1.500

ω =1.000

1600
1500
1400
1300
1200
1100
1000
0102030405060b.)
Fig. 5. Step response results when various the ω atconditions step setpoint 1200 to 1600 rpm, Kc=3.065,Ti=0.661, and a.)no load b.) full load.
4. Conclusion
DC motor speed control system with interface card dSPACE
DS1104 series is designed to control the speed of the motor byconsidering the effect of ,ω load, (Load) and speed (Speed) canbe summarized and recommendations are as follows.

[1] Santi Wangnipparnto and Tianchai suksri, “Thermalconductivity tester,” Proceeding of ECTI-CON 2007
international conference organized by ElectricalEngineering/Electronics, Computer, Chiangrai, Thailand,
2007[2] Satean Tunyasrirut and Santi Wangnipparnto,“Electromagnetic flux density controlled by fuzzy logicMethod,” Proceeding of ECTI-CON 2007 international
conference organized by Electrical Engineering/Electronics, Computer, Chiangrai, Thailand, 2007, pp.
205-207.
[3] Satean Tunyasrirut and Santi Wangnipparnto, “Levelcontrol in horizontal tank by Fuzzy PID cascadecontroller” Transaction on Engineering, Computing andTechnology V19, Bangkok, Thailand,
pp. 78-82, January 2007.
[4] Satean Tunyasrirut, Santi Wangnipparnto andAttapol Kanchanathep “Position control of Linear
Pneumatics Actuator by fuzzy logic controller,”
Proceeding of the 2nd Regional Conference onArtificial Life and Robotics, Songkhla, Thailand,
14 – 15 July, pp. 34-36, 2006.
[5] Satean Tunyasrirut and Santi Wangnipparnto, “ Levelcontrol in horizontal tank by fuzzy logic controller”
SICE- ICASE International Joint Conference 2006,
BEXCO(Busan Exhibition& Convention Center), Busan,KOREA, 18-21 October, 2006.