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1111111 ~111~1 ~1~1~1111~1 ~lfl~I~1111 ~lrl~1111111 ~lilll~111111111 3 0000 00110234 6
CONTROL STRATE Gffi S FOR AUTOMAT][C GANTRY CRANE SYSTEM
BY
JAMAL UD][N JALANl
][NTERNAT][ONAL ][SLAM][C 1UNWJERS][TY MALAYS][A
J1UNE 2005
CONTROL STRATEGIES FOR AUTOMATIC GANTRY CRANE SYSTEM
BY
JAMAlL lUIDIN JAJLANI
A DISSERTATION SlUBMITTED IN PARTIAL FlULFILMENT OF TlHlJE REQ1[J]IJR]EMENTS
FOR TlHlJE DEGREE OF MASTER OF SCRENCE liN MEC1ffiA TRONIC§
ENGliNEERJING
KlULLliYYAH OF ENGliNEERJING INTERNATIONAL ISLAMIC lUNlMERSITY
MAlLAYSliA
ruNE 2005
ABSTRACT
Gantry crane is a machine that moves payload from one point to another point.
Nowadays, most of gantry cranes use open loop system to control position while anti
swing control is operated manually by skillful operators. The open loop system is
sensitive to the parameter variations and disturbances while operator's skills are
restricted by fatigue problem and will affect the performance of the gantry crane. In
order to overcome the problems, feedback control is adopted in this study. Firstly,
classical PID and PD were introduced as position and anti-swing control respectively.
The experimental result showed that the PID and PD controllers were successfully
controlled both position and swing of the gantry crane especially for small load
displacement. However, the positioning performance was degraded due to the
saturation of the actuator. In addition, the PID controller design is a time consuming
process, since model and parameters of the gantry crane are needed. Secondly, non
model based of fuzzy logic controllers are implemented in the gantry crane system for
position and anti-swing control. The experimental result showed that fuzzy logic
controllers had resulted on good performances for anti-swing controller. However, the
results for position control were inconsistent for small desired position. The tuning
process may improve the control performance but it may affect other desired
positions. Finally, non-model based of NCTF controller, was proposed for position
control of the gantry crane system while the anti-swing control by using fuzzy logic
controller remained the same since it gave good performance. The experimental result
showed that the NCTF controller produced best results for position control of the
gantry crane system compared to other controllers.
11
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d.>.-J..A; )81 t!:r' CyAlI i..f)I...u1 ilkJI 0) .~l!ll ~I iLhi ~ oJ~ oygll
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l) ~I ~ (" ..w ,j5'WI o.u, ~ ~I J>--i if).c!)I JJI ~bi l) )~
4....LQj ~ ~..\.).A:JI PID ,PD t},j.-.i 01 '~i~IJ...u1 o.u, l) oJ.j)1 ~..wl
~.rdl ~I ~)i ~) .el::l~ ~l!ll ~I iLhi) c!rD ~I) 0:::)Ll5'
JJ'JI ~bi) c!}1 l) ~I if C~ l:5:..c ~ PD) PID ~I)I t},j.-.I 01
~b~1 0~ ,~.) C::) .0~1 ..:..o~..,.J-I ~ ~ ~ 4...,ob:. oJ~) WI)I
PID ~I)I Y j.-.i ~ 0i Jl 4jl.,;:>)'~ .J-WI ~ ~ .J f (" ~ Jo ~I
.c!)I JJ'J 0~1 ~I) ~.)~ Lp) d.>.-lll ..:..its" ~ .ci}J ~ ~
JJI Lhi·~ I.~ '-" - .)·i I" J...::......j ~ - II;;..;, ·\1 ;;".....LA]I ~I)I ~i 01 ,l..i~ i '-:?~{~.r~ I..? y--" - -. <-
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~bi ~ 0i ~I if ~.rII~) .~~)I 0~1 c!l}1 c:: wlp ~ c!}1
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iLhi ~ c!)I JJI ~~ )J.j esJI c!lrD \..p-Ifl1 (" ~.)Y:~1 ~ i~ ~ ~I
~bi ~ til1 </' LS c11 U yJ.I ~l"ill ~I)I ~i il~~ ~l!ll ~\
~i ~b..:....o~ NCTF ~I)I ~i 0i ~.rdl ~I ~)i) .\~
.~I)I ~i ~ c:: :ijJW~ c!)1 JJI itt.; c!r oJb)'
iii
APPROVAL PAGE
I certify that I have supervised and read this study and that in my opinion, it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a thesis for the degree of Master of Science in Mechatronics Engineering.
w~c2···························· su~i~sor I certify that I have read this study and that in my opinion, it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a thesis for the degree of Master of Science in Mechatronics Engineering.
~ ...... ~ ............................. . Abdulgani Albagul Internal Examiner
I certify that I have read this study and that, in my opinion, it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a thesis for the degree of Master of Science in Mechatronics Engineering.
The thesis was submitted to the Department of Mechatronics Engineering and is accepted as pmiial fulfilment of the requirements for the degree of Master of Science in Mechatronics Engineering. $7-
....... /~~~" ................ . Mir Nasiri Nazim Head, Depmiment of Mechatronics Engineering
The thesis was submitted to the Kulliyah of Engineering and is accepted as partial fulfilment of the requirements for the degree of Master of Science in Mechatroni s Engineering. ~
lmad Faris Ismail Dean, Kulliyyah of Engineering
IV
DECLARATION
I hereby declare that this thesis is the result of my own investigations, except where
otherwise stated. Other sources are acknowledged by footnotes giving explicit
references and a bibliography is appended.
Name: lamaludin lalani
"JLw.eI,,~~l Signature: ... ~i~~ ••••••••••••••••••••
"'1 / % G" Date: ............................ .
v
INTERNATIONAL ISLAMIC UNIVERSITY MALAYSIA
DECLARATION OF COPYRIGHT AND AFFIRMATION OF FAIR USE OF UNPUBLISHED RESEARCH
Copyright © 2005 by lamaludin lalani. All rights reserved.
CONTROL STRATEGIES FOR AUTOMATIC GANTRY CRANE SYSTEM
No part of this unpublished research may be reproduced, stored in a retrieval system, or
transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or
otherwise without prior written permission ofthe copyright holder except as provided below.
1. Any material contained in or derived from this unpublished research may only be used by others in their writing with due acknowledgement.
2. HUM or its library will have the right to make transmit copies (print of electronic) for institutional and academic purposes.
3. The HUM library will have the right to make, store in a retrieval system and supply copies of this unpublished research if requested by other universities and research libraries.
Affirmed by lamaludin lalani
~~~t .L •• ,~~ •••••••••••••••
Signature Date
VI
Jalani Cltulas, Alimah Hamzah, Nllrlll Alwani Atltiralt
Vll
ACKNOWLEDGEMENTS
Alhamdulillah, all praise to Allah, the Most Beneficcnt and the Most Merciful, who has taught what I knew not. It is by the grace of the Almighty Allah that this research work has been completed successfully.
A deepest appreciation is dedicated to Dr Wahyudi Martono for his extraordinary patience and his enduring optimism. I really admire his knowledge, intelligence and patience. I do appreciate his dedicated guidance, suggestion, critical comments and warm support which have given me the opportunity to develop my research skills. I am blessed and honored to be his student.
Also a special thanks to the academic and technical staff of the Mechatronics Engineering Department, International Islamic University, Malaysia. They have assisted me in giving advices, ideas, and technical supports to this research project in the spirit of brotherhood of Islam.
I would like to thank all my friends especially to the fellow brothers in the Research Laboratory who have been keeping the atmosphere of research in the laboratory lively.
Finally, my sincere gratitude goes to my beloved family especially my parents for their love, endless encouragement and D'ua. They are truly my inspiration.
\'111
PUBLICATIONS
1. Jamaludin, Wahyudi, Suhaimi and Iswanaini "Development of Automatic Gantry Crane, Partl: Modeling and Parameters Identification", Proceeding of the Sixth Industrial Seminar (lES 2004) Campus EEPIS-ITS, Surabaya Indonesia, October 12, 2004, pp.306-311.
11. Jamaludin, Wahyudi, Suhaimi and Iswanaini "Development of Automatic Gantry Crane, Part2: Controller Design and Implementation", Proceeding of the Sixth Industrial Seminar (lES 2004) Campus EEPIS-ITS, Surabaya Indonesia, October 12, 2004, pp. 312-315.
Ill. Wahyudi, Jamaludin and Riza Muhida "Mechatronics Design of An Automatic Gantry Crane", Proceeding of International Conference on Product Design & Development ICPDD 2004, Kota Kinabalu Sabah Malaysia, December 20-23,2004, pp. 123-127.
iv. Wahyudi and Jamaludin, "Design and Implementation of Fuzzy Logic Controller for Automatic Gantl)! Crane System", Accepted for the Second International Conference On Mechatronics, Pan Pacific Hotel, Kuala Lumpur Malaysia, May 10-12,2005.
v. Wahyudi and Jamaludin, "Hardware-ill-the-Loop-Simulation (HILS) Based on Designed and Robustness Evaluation of an Intelligent Gantry Crane System", Accepted for International Conference on Control, Automation and System, KlNTEX, Gyeonggi Do, Korea,June 2-5, 2005.
IX
TABLE OF CONTENTS
Abstract (English) ........................................................................ II
Abstract (Arabic) ....... ................................ ...... ............................ III
Approval Page............................................................................ iv Declaration..................................................................... ........... v Copy right Page......... .................................... ............................... VI
Dedication............... .................................................................... VII
Acknowledgements.... ......... ............... ......... ............. ..... ... .. ....... . ... VIll
Publications................................................................................. IX
List of Tables ....... ...... ... ..... ....... ............... ........................... .... .... XII
List of Figures............................................................................. Xlll
List of SyYl1bols............................................................................. xv List of Abbreviations .................................................................. '" XVII
CHAPTER l:INTRODUCTION ............... .......... .......... ........ ............ I 1.1 Background................................................................. I 1.2 Objective ..................................................................... 4 1.3 Methodology............................................................... 4 1.4 Organization of Thesis ...... ............. ........ .......... ........ ................ ..... 5
CHAPTER 2:MODELING AND PARAMETERS IDENTIFICATION ....... 7 2.1 Introduction........................................................... ...... 7 2.2 System Description....................................................... 7 2.3 Modeling and parameters identification........ ................. ....... 9
2.3.1 Mathematical modeling ....................................................... 9 2.3.2 Parameters identification ..................................................... 18
2.4 Experimental setup ......................................................... 23 2.5 Results ........................................................................ 24
2.5. I Parameters identification results ................................ 24 2.5.2 Model validation .................................................. 26
2.6 Conclusion................................................................ 27
CHAPTER 3:DESIGN AND IMPLEMENTATION OF CLASSICAL PID CONTROLLER................................................ ......... 28
3.1 Introduction.................... ............................................ 28 3.2 Proposed controller structure ........................................................... 28 3.3 Controller design ............................................................................. 30
3.3.1 Nonlinear control design (NCD) blockset .................... 30 3.3.2 Parameters optimization result ........................................ 33
3.4 Experimental setup ........................................................ 33 3.5 Results ............................................................................................ 34
3.5.1 System performances .......................................................... 34 3.5.2 Robustness evaluation ......................................................... 40
3.6 Conclusion .................................................................. 42
CHAPTER4:DESIGN AND IMPLEMENTATION OF FUZZY LOGIC CONTROLLER......................................................... ·D
4.1 Introduction ................................................................. 43 4.2 Proposed controller structure ............................................ 43 4.3 Basic concept of fuzzy logic controller............ ..................... 44 4.4 Controller design............ ...... ...................... ........... ...... 45
4.4.1 Membership functions................................. .......... 46 4.4.2 Generated linguistic rules....................................... 49 4.4.3 Fuzzy inference and defuzzification ........................... 56
4.5 Results...................................... ........... ...................... 57 4.5.1 System performances ............................................. 57 4.5.2 Robustness evaluation ........................................... 62
4.6 Conclusion........................................................ ... ....... 63
CHAPTER 5:DESIGN AND IMPLEMENTATION OF NCTF CONTROLLER....................... .................................. 64
5.1 Introduction....................... .................................... ..... 64 5.2 Proposed controller structure.................. .......................... 64 5.3 Basic concept ofNCTF controller ....................................... 65 5.4 Controller design..................................................... ..... 69
5.4.1 NCT determination ................................................ 69 5.4.2 Design of compensator ........................................... 71
5.5 Results....................... ................................... ........ ..... 75 5.5.1 System performances ............................................. 75 5.5.2 Robustness evaluation.............................. .... .... ..... 82
5.6 Conclusion....................... ....................... .................... 83
CHAPTER 6:CONCLUSIONS ....................... ............................. ..... 84 6.1 Conclusions....................... ........................ .............. ..... 84 6.2 Further studies ............................................................... 86
BIBLIOGRAPHy ........................................................................... 87
XI
LIST OF TABLES
Table No. Page
3.1 Initial value ofPID and PD controllers 33
3.2 Parameters ofPID and PD controllers 33
3.3 Positioning performance 39
3.4 Anti-swing performance 40
3.5 Performance due to the length ( /! ) variations 41
4.1 The generated fuzzy rules of position control 49
4.2 The generated fuzzy rules of anti-swing control 51
4.3 Positioning performances 61
4.4 Anti-swing performances 61
4.5 Performance due to the length ( /! ) variations 63
5.1 PI compensator parameters design 72
5.2 Comparison of the performances for different compensator to the step input 75
5.3 Positioning performances for NCTF controller 77
5.4 Positioning performances 81
5.5 Anti-swing performances 81
5.6 Performance due to the length ( /! ) variations 83
Xli
LIST OF FIGURES
Figure No. Page
1.1 Gantry crane
2.1 Lab-scale gantry crane system 9
2.2 Block body diagram of gantry crane system 10
2.3 Equivalent circuit of the DC motor 13
2.4 Forces on the rack and pinion assembly 15
2.5 Gantry crane model 18
2.6 Step response of unknown system G(s) 19
2.7 Determination ofK] 20
2.8 Determination ofK2 21
2.9 Block diagram of parameters identification of gantry crane model 22
2.10 Serial connection between host and target computers to the gantry crane 23
2.11 Experimental step response of angular velocity of the motor 24
'" 2.12 Functionvl(t)=f[Ko-vu(t)]dt 25
o
'" 2.13 Function v 2 (t)= f[KI-vl(t)]dt 25
o
2.14 Block diagram of obtained transfer function 26
2.15 Measured and simulated responses 27
3.1 Schematic diagram of gantry crane system using PID and PO Controllers 29
3.2 Simplified schematic diagram of gantry crane system 29
3.3 Simulink model 31
3.4 Constraint window before adjustment 31
3.5 Desired performance of position control 32
3.6 Desired performance of anti-swing control 32
3.7 Responses to a 10 em step input 36
3.8 Responses to a 40 em step input 37
3.9 Responses to a 70 em step input 38
3.10 Control signal due to the saturation of the actuator 39
Xlll
3.11 Robustness ofPD controller by simulation 41
4.l Schematic diagram of gantry crane using fuzzy logic controller 44
4.2 Fuzzy controller 45
4.3 Membership function of position control 47
4.4 Membership function of anti-swing control 48
4.5 Illustration of how fuzzy rules can cover all possible positions 50
4.6 Illustration of how fuzzy rules can cover all possible swing angles 53
4.7 Physical movement of the trolley for position control 54
4.8 Physical movement of the trolley for position control 55
4.9 Responses to a 10 cm step input 58
4.l0 Responses to a 40 cm step input 59
4.11 Responses to a 70 cm step input 60
4.12 Robustness of the fuzzy logic controller by simulation 62
5.l Schematic diagram of using NCTF and fuzzy logic controller 65
5.2 NCTF control system 66
5.3 NeT and object motion 66
5.4 NCT determination 67
5.5 Simple open-loop response of the gantry crane for NCT determination 70
5.6 Construction ofNCT oflab-scale gantry crane 71
5.7 Responses on phase plane 73
5.8 Responses at different positions 74
5.9 Responses to a 10 cm, 40 cm and 70 cm step input 77
5.l0 Responses to a 10 cm step input 78
5.11 Responses to a 40 cm step input 79
5.12 Responses to a 70 cm step input 80
5.13 Robustness of the Fuzzy logic controller by simulation 82
xiv
LIST OF SYMBOLS
a j system parameter
a2 system parameter
A curve area
b rack damping coefficient
e error
eb back emf
F summation external forces for linear motion
g gravity
h maximum error rate
current
J mass moment of inertia
J m moment inertia of motor
Jo total of moment inertia
J p moment of inertia of rack-pinion
K kinetic energy
Ko system parameter
Kj artificial system parameter
K2 artificial system parameter
Kd derivative gain
Kj integral gain
Kg gear ratio constant
KjOad
kinetic energy of the load
Km motor constant
Kp proportional gain
Ktrolley kinetic energy ofthe trolley
f. length of the string
L lagrangian
Lind inductance
xv
m inclination of the NCT near origin
m! mass of the trolley
m 2 mass of the load
P potential energy
r pitch radii of rack-pinion
R resistance
t time
T summation external torques for rotational motion
Tm torque
u voltage
U o control input voltage
up difference actual error rate and NCT
u r rated input to the actuator
v velocity of the motor
V L velocity of the load
v steady state velocity ss
V T velocity of the trolley
V LIT velocity of the load relative to the trolley
x displacement
8 angle of the string moves
v maximum operator
/\ minimum operator
S damping ratio
O)n natural frequency
a simplified object parameter
XVI
COA
DAQ
GUI
I/O
N
NB
NCD
NCTF
NS
P
PB
PD
PI
PID
PS
PTP
RTW
TCP/IP
Z
LIST OF ABBREVIATIONS
Centre of Area
Data Acquisition Card
Graphical User Interface
Input/Output
Negative
Negative Big
Nonlinear Control Design
Nominal Characteristic Trajectory Following
Negative Small
Positive
Positive Big
Proportional Derivative
Proportional Integral
Proportional Integral Derivative
Positive Small
Point to Point
Real-Time Workshop
Transmission Control Protocol/Intemet Protocol
Zero
XVll
CHAPTER!
INTRODUCTION
1.1 Background
Crane is a machine for gripping, lifting and moving loads horizontally, as well
as lowering and release the gripper back, Omar (2003). These tasks are performed
with the aid of hoisting mechanism that works as an integral part of the crane. Cranes
are widely used in industry for transporting heavy loads and hazardous materials in
shipyards, factories, nuclear installations and high building constructions. In general,
there are two types of crane namely rotary cranes and gantry cranes. Rotary cranes are
commonly use in shipyard and construction site. This type of crane involves rotation
movement during operation. The typical gantry crane is shown in Figure 1.1.
Figure 1.1: Gantry crane
The gantry crane should move loads as fast as possible without causing any
excessive movement at the final position, thus it can achieve higher productivity. This
type of crane incorporates a trolIey which moves over the jib (girder) and translates in
a horizontal plane. In some cases, the jib is mounted on another set of orthogonal
railings calIed bridge cranes. Furthermore, the payload is attached to the trolIey by a
cable. The length can be varied by hoisting mechanism.
Nowadays, most of the current gantry cranes in industry are open loop systems
which are operated by operators. The operators use joystick to control position in two
directions of vertical and horizontal. When moving it horizontally, a constant
acceleration is generated until the maximum velocity is gained. On the other hand,
moving vertically is only lowering and lifting the cable, therefore the load can be
removed immediately. The joysticks have analog control, which means that the
amplitude of the acceleration can be controlled. When the joystick is released the
trolley decelerates until it stops. Here, the performance of the gantry crane depends on
the skill of the operators. The company that hired the operators needs to train them
properly in order for them to work effectively and safely during gantry crane
operation.
As mentioned earlier, most of the common gantry cranes are open-loop
systems that swing when payload is suddenly stopped after a fast motion. The swing
motion can be reduced and stopped without using the controller. However, it will be
time consuming and eventually reduce the productivity of the gantry crane system.
Even though the skillful operators who operate the crane, they still face some
constraints such as fatigue problem. This phenomenon can cause inconsistent
performance of the gantry crane systems and might cause accident.
2
Various attempts in controlling gantry cranes system based on open loop
system were proposed. For example, open loop time optimal strategies were applied
to the crane by many researchers such as Yamagashi (1974), Sakawa and Shindo
(1981), Manson (1982), Auernig and Troger, (1987). They came out with poor results
because open loop strategy is sensitive to the system parameters (e.g. rope length) and
could not compensate for wind disturbances. Another importance of open loop
strategy is the input shaping introduced by Karnopp (1992), Teo (1998) and Singhose
(1997). Even though they claimed that input shaping is good in controlling the open
loop system but it still faces sensitiveness to the external disturbances and parameter
variations.
On the contrary, feedback control is well known to be less sensitive to
disturbances and parameter variations. Hence, it is an attractive method for crane
control design. Ridout (1989) developed a controller, which feeds back the trolley
position, speed and load swing angle. Through this approach, the system damping can
be changed during the transferring of the load. Many researchers proposed the
controllers based on feedback system. For example Mita and Kanai (1979) proposed
optimal control, Boustany and d'Andrea-Novel (1992) introduced adaptive control,
and Cheng and Chen (1996) have developed linearization techniques. However, in
general closed-loop control systems, it is designed based on the exact model and
parameters of the plant. It is known that the mathematical modeling including
parameters identification is complicated and time consuming due to nonlinearity
dynamics of gantry crane system. Recent work on gantry crane control system was
presented by Omar (2003). The author had proposed PD controller for position
control and three different methods for anti-swing control namely a classical PO
controller, delayed feedback technique and fuzzy logic controller. All these
3
controllers were designed based on mathematical model of the crane except fuzzy
logic controller. However, this fuzzy logic controller uses mapping method which
needs delayed feedback technique before fuzzy logic controller can be designed. This
strategy was time consuming because fuzzy logic controller could not be implemented
directly and relied on other controller to fulfill the design.
The scope of a lab-scale gantry crane system was used in the experimental
study that only considers the planar movement of trolley with fixed load and length of
string. The lifting and unloading of load is not considered and the velocity of the
trolley remains constant. The experimental study was implemented to identify
parameters of the gantry crane system and to examine performances of the controllers.
1.2 Objective
The objective of the study is to investigate the appropriate control method for
gantry crane system. The controller is expected to have simple structure, easy to
design and also robust to the parameter uncertainties.
1.3 Methodology
In order to achieve the objectives of this research, the following procedures
are considered:
1. The research starts with the understanding of the gantry crane background,
analyzes its problems and investigates control theory which has been applied
to the gantry crane system.
ii. A mathematical model of lab-scale gantry crane system is developed.
lll. Investigate the conventional control method (PID and PD controllers) which
has been applied to the gantry crane system.
4
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