modeling of semi-active magnetorheological damper …
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MODELING OF SEMI-ACTIVE
MAGNETORHEOLOGICAL DAMPER FOR
AUTOMOBILE SUSPENSION SYSTEM
BY
MAHMUDUR RAHMAN
A dissertation submitted in fulfilment of the requirement for
the degree of Master of Science in Mechatronics
Engineering
Kulliyyah of Engineering
International Islamic University Malaysia
DECEMBER 2014
ii
ABSTRACT
The design of vehicle suspension systems is an active research field in which one of
the objectives is to improve the passenger’s comfort through the vibration reduction of
the internal engine and external road disturbances. Comfort and road handling in car
can be improved by including a semi-active suspension system, controlled by varying
the damping based on measurements of the vehicle motions. This research deals with
design and development of a quarter-car suspension using magneto-rheological
damper (MR). A quarter-car of two degree-of-freedom (DOF) system is designed and
constructed on the basis of the concept of a four-wheel independent suspension to
simulate the actions of a semi-active vehicle suspension system. The selection of an
appropriate MR damper model is crucial, since it provides the suitable current and
force relationship and allows finding the appropriate force to the system. The
behavioral characteristic of selected MR damper model is simulated and analyzed
with different current input. An effective control structure is a key function of this
research to determine the complexity of the control design and parameter tuning
process. The performance of Proportional Integral Derivative (PID) and Linear
Control Regulator (LQR) controller is designed based on the system requirements. In
this research, the PID controller is verified experimentally under different road
excitations to improve the ride quality and vehicle safety.
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 fully adequate, in scope and
quality, as a dissertation for the degree of Master of Science in Mechatronics
Engineering.
….………………..……………
Muhammad Mahbubur Rashid
Supervisor
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
dissertation for the degree of Master of Science in Mechatronics Engineering.
.……………..…………………
Iskandar Al-Thani
Examiner
This dissertation was submitted to the Department of Mechatronics Engineering and is
accepted as a fulfilment of the requirement for the degree of Master of Science in
Mechatronics Engineering.
……………..………………….
Md. Raisuddin Khan
Head, Department of
Mechatronics Engineering
This dissertation was submitted to the Kulliyyah of Engineering and is accepted as a
fulfilment of the requirement for the degree of Master of Science in Mechatronics
Engineering.
..……………………………….
Md. Noor Bin Saleh
Dean, Kulliyah of Engineering
iv
DECLARATION
I hereby declare that this dissertation is the result of my own investigations, except
where otherwise stated. I also declare that it has not been previously or concurrently
submitted as a whole for any other degrees at IIUM or other institutions.
Mahmudur Rahman
Signature ………………………………. Date ......…………………
v
INTERNATIONAL ISLAMIC UNIVERSITY MALAYSIA
DECLARATION OF COPYRIGHT AND AFFIRMATION
OF FAIR USE OF UNPUBLISHED RESEARCH
Copyright © 2014 by International Islamic University Malaysia. All rights
reserved.
MODELING OF SEMI-ACTIVE MAGNETORHEOLOGICAL DAMPER
FOR AUTOMOBILE SUSPENSION SYSTEM
I hereby affirm that the International Islamic University Malaysia (IIUM) hold all
the rights in the copyright of this Work and henceforth any reproduction or use in
any form or by means whatsoever is prohibited without the written consent of
IIUM. No part of this unpublished research may be reproduced, stored in a retrieval
system, or transmitted, in any form or by means, electronic, mechanical,
photocopying, recording or otherwise without prior written permission of the
copyright holder.
Affirmed by Mahmudur Rahman
…………………….. ……………………..
Signature Date
vi
TO MY BELOVED PARENTS AND WIFE
vii
ACKNOWLEDGEMENTS
First of all, praise to Allah (swt), for His blessing to give me the ability and
knowledge to complete the research work fruitfully.
I would like express my deepest gratitude to my supervisor Dr. Muhammad Mahbubur
Rashid, for his effort, guidance and support throughout the project. Also I must thank
him for his kindness to take me as a research assistant.
Also I must mention my co-supervisor Dr. Asan Gani Abdul Muthalif for his
extensive guidance and support, without him the project would have not been
successful to achieve the objectives of this research.
Thanks to all lectures who have taught me and guide to successfully finish the
research. Also I must remember all of my friends for theirs ideas and support
especially S.M Hasanul Banna Kasemi. Thank to him for his valuable suggestion and
co-operation as not only a colleague but also a good friend.
Finally, I proudly mention my parents family members who are always there for me
when matters most, especially my mother for her love and inspiration throughout my
study.
viii
TABLE OF CONTENTS
Abstract ...................................................................................................................... ii
Approval Page ............................................................................................................ iii
Declaration ................................................................................................................. iv
Copyright Page ........................................................................................................... v
Acknowledgments ...................................................................................................... vii
List of Tables ............................................................................................................. xi
List of Figures ............................................................................................................ xii
List of Symbols ......................................................................................................... xv
List of Abbreviations ................................................................................................. xvi
CHAPTER ONE: INTRODUCTION .................................................................... 1
1.1 Motivation................................................................................................. 1
1.2 Overview................................................................................................... 2
1.2.1 Background of MR damper and its applications ........................... 3
1.2.2 Keywords ....................................................................................... 4
1.2.2.1 Semi-active .......................................................................... 4
1.2.2.2 Magnetorheological (MR) ................................................... 5
1.2.2.3 Quarter-car ........................................................................... 6
1.2.2.3 Controller Design ................................................................ 6
1.3 Literature Review Technique ................................................................... 7
1.4 Problem Statement .................................................................................... 8
1.4 Research Objectives.................................................................................. 8
1.4 Research Methodology ............................................................................. 9
1.5 Scope of Research..................................................................................... 10
1.6 Outline of the Dissertation ........................................................................ 11
CHAPTER TWO: LITERATURE REVIEW ....................................................... 12
2.1 Introduction............................................................................................... 12
2.2 Vehicle Suspension ................................................................................... 12
2.2.1 Ride Comfort .................................................................................. 13
2.2.2 Vehicle Handling ............................................................................ 14
2.3 Vibration Control Strategy ....................................................................... 15
2.3.1 Passive Vibration Control Strategy ................................................ 15
2.3.2 Active Vibration Control Strategy ................................................. 15
2.3.3 Semi-active Vibration Control Strategy ......................................... 16
2.4 Magnetorheological Dampers ................................................................... 18
2.4.1 Magnetorheologfical Fluid ............................................................. 18
2.4.1.1 MR fluid Components ........................................................ 20
2.4.1.2 MR Fluid Modes of Operation ........................................... 20
2.4.1.3 Application of MR fluid ..................................................... 22
2.4.2 Magnetorheological Fluid Damper ................................................ 23
2.4.2.1 Applications of MR damper ................................................ 24
2.4.2.2 Operating Principle of MR damper ..................................... 25
ix
2.5 Models For MR Damper ........................................................................... 26
2.5.1 Overview of MR damper Models .................................................. 26
2.5.2 MR Damper Models ....................................................................... 29
2.5.2.1 Bingham Model ................................................................... 29
2.5.2.2 Gaomota and Filisko Model ................................................ 31
2.5.2.3 Li Model .............................................................................. 33
2.5.2.4 Bouc-wen Model ................................................................. 35
2.5.2.5 Modified Bouc-wen Model ................................................. 37
2.5.3 Selection of MR Damper Model .................................................... 41
2.6 Quarter-car Model .................................................................................... 42
2.7 Different Control Schemes ....................................................................... 44
2.7.1 Overview of Different Control Policies .......................................... 44
2.7.2 Selected Control Schemes .............................................................. 46
2.7.2.1 PID Control ......................................................................... 46
2.7.2.2 LQR Control ....................................................................... 48
2.8 Summary ................................................................................................... 51
CHAPTER THREE: MODELING, CONTROLLER DESIGN AND
SIMULATION ......................................................................................................... 52
3.1 Introduction............................................................................................... 52
3.2 Simulation of MR damper Model ............................................................. 52
3.3 Modeling of Semi-active Quarter-car System .......................................... 55
3.4 Controller Design...................................................................................... 57
3.5.1 Design of Quarter-car Control Structure with PID Controller ....... 58
3.5.2 Design of Quarter-car Control Structure with LQR Controller ..... 59
3.5 Simulation Results .................................................................................... 60
3.6 Summary ................................................................................................... 62
CHAPTER FOUR: EXPERIMENTAL SETUP ................................................... 64 4.1 Introduction............................................................................................... 64
4.2 Structural Design of Quarter-car .............................................................. 65
4.2.1 Materials for Prototype ................................................................... 66
4.3 MR Damper .............................................................................................. 68
4.4 Controller Device for MR Damper ........................................................... 71
4.5 Sensory Information and Data Acquisition System.................................. 73
4.5.1 Sensory Information ....................................................................... 73
4.5.2 Data Acquisition (DAQ) System .................................................... 74
4.6 Vibration Test System .............................................................................. 75
4.7 Experimental Setup ................................................................................... 75
4.8 Summary ................................................................................................... 77
CHAPTER FIVE: EXPERIMENTAL TESTS AND RESULTS ........................ 78
5.1 Introduction............................................................................................... 78
5.2 Experimental Input ................................................................................... 78
5.2.1 Excitation Input .............................................................................. 78
5.3 Experimental Results ................................................................................ 79
5.3.1 Sine Input ....................................................................................... 79
5.3.1.1 Damper off (Uncontrolled) .................................................. 79
5.3.1.2 Damper on (Controlled) ...................................................... 82
x
5.3.2 Random Input ................................................................................. 85
5.4 Summary ................................................................................................... 87
CHAPTER SIX: CONCLUSION AND RECOMMENDATION ........................ 88 6.1 Conclusion ................................................................................................ 88
6.2 Recommendation ...................................................................................... 90
REFERENCES ......................................................................................................... 92
LIST OF PUBLICATIONS .................................................................................... 96
APPENDIX A ........................................................................................................... 97
APPENDIX B ........................................................................................................... 100
xi
LIST OF TABLES
Table No Page No.
2.1 Comparison among passive, active and semi-active
strategies
17
2.2
2.3
2.4
Comparison of rheological structure among five MR
damper models
Calculated error for MR damper models
MR fluid behavioral scenarios for MR damper models
40
41
42
2.5 Effect of increasing the PID gains
47
2.6 Ziegler-Nichols tuning rules
48
3.1 The system parameters
57
3.2 Performance of the system with and without controllers
61
4.1 Materials for prototype development
66
4.2 Typical properties of RD-8041-1 MR damper
71
4.3 Electrical properties of RD-8041-1 MR damper
71
5.1 Comparison of acceleration and displacement between
Controlled and Uncontrolled system
85
xii
LIST OF FIGURES
Figure No Page No.
1.1 Literature Review Flowchart 7
1.2 Block diagram showing research methodology 10
2.1 Typical construction of (a) Passive, (b) Active and (c)
Semi-active suspension system
17
2.2 The behavior of MR fluid with and without magnetic field. 19
2.3 MR fluid particles. 20
2.4 MR fluid modes: (a) Valve mode, (b) Shear mode, and (c)
Squeeze mode
22
2.5 Basic operating principle of MR dampers 26
2.6 Rheological structure for Bingham Model 30
2.7 Comparison between predicted and experimental response
for Bingham model.
31
2.8 Structure of Gamota-Filisko model. 32
2.9 Comparison between the predicted and experimental
response for Gamota-Filisko model
33
2.10 The rheological structure of MR damper for Li model 34
2.11 Comparison between (a) predicted and (b) experimental
response for Li model
35
2.12 Rheological structure for Bouc-wen model 36
2.13 Comparison between predicted and experimental response
for Bouc-wen model
37
2.14 Rheological structure for Modified Bouc wen model 37
2.15 Comparison between predicted and experimental response
for Modified Bouc-wen model
38
2.16 Quarter-car model 43
2.17 A typical PID control structure 46
xiii
3.1 Schematic of MR damper model in Simulink 53
3.2 MR damper force response versus Time 54
3.3 MR damper force response versus displacement 54
3.4 The Quarter-car model 55
3.5 Schematic of Quarter-car model 56
3.6 Block diagram of Semi-active control system 57
3.7 Quarter-car system with PID controller 58
3.8 Relative body displacements for step response 61
3.9 Relative displacement for controlled and uncontrolled
system under sine excitation
62
4.1 Schematic diagram of Test rig set up 64
4.2 Prototype design of Quarter car 65
4.3 Materials for Quarter car prototype 67
4.4 (a) Schematic MR damper and (b) RD-8041-1 MR damper 69
4.5 MR damper assembly drawing 70
4.6 Wonder Box Device Controller- RD-3002-03 72
4.7 Voltage and current relationship (Measured) in the Wonder
Box Device Controller- RD-3002-03
73
4.8 Typical ICP sensor system 74
4.9 Components of DAQ system 74
4.10 Vibration Test system 75
4.11 Experimental set-up 76
5.1 Frequency responses at 20-30Hz 80
5.2 Body and wheel acceleration (m/s2) 81
5.3 When damper is off: (a) Relative acceleration (m/s2) and
(b) Relative displacement (m)
82
5.4 Semi-active quarter-car with PID controller 83
xiv
5.5 Relative acceleration 83
5.6 Comparison between controlled and uncontrolled relative
displacement of the vehicle body
84
5.7 Compare between controlled and uncontrolled system for
(a) acceleration and (b) displacement under random signal
86
xv
LIST OF SYMBOLS
𝛾 Fluid shear strain rate
𝜏 Shear stress
𝜏𝑦 Yield stress
𝜂 Plastic viscosity
𝑐0 Damping coefficient
𝑓𝑐 Frictional force
𝑥 Velocities
𝛼 Bouc-Wen model design parameter
𝛽 Bouc-Wen model design parameter
k Spring coefficient
c Damping coefficient
z Hysteresis variable component
𝛼𝑎 Coulomb force of MR damper
v Applied voltage
I Input current to MR damper
𝛿 Scale factor that determines the width of the hysteresis
𝐹𝑦 Yield force
𝑥 𝑦 Yield velocity
xvi
LIST OF ABBREVIATIONS
et al. (et alia): and others
Hz Hertz (Unit of frequency)
Kg Kilogram (Unit of mass)
m Meter (Unit of length)
mm Millimeter
MR
ER
Magnetorheological
Electrorheolgical
N Newton (Unit of force)
PID Proportional Integral Derivative
s
LQR
PSD
RMS
DAQ
Second (Unit of time)
Linear Quadratic Regulator
Power Spectral Density
Root Mean Square
Data Acquisition
1
CHAPTER ONE
INTRODUCTION
The objective of this chapter is to deliver the reader a background of this research. The
importance to design suspension system to provide passenger comfort is highlighted.
To design suitable suspension, extensive literatures are studied which motivates to
research to improve the system. The basic background of magneto-rhetorical fluid and
damper are provided with brief idea of main keywords of this research. The objectives
are set based on the problem statement. The methodology and research flowchart are
also presented in this chapter.
1.1 MOTIVATION
Drivers and passengers of vehicles are often exposed with vibrations. People spend
long time inside cars to travel for various work purposes. So the continuous vibrations
of the car not only harm health and physical conditions but also become a reason for
early fatigue and decline of ride performance. Moreover, depending on the present
necessity to drive fast in critical situations, safety car with reduced vibration is
important. In this situation, improving the passenger comfort and safety of vehicles is
essential. This upgrading can be accomplished with developing an efficient
suspension system.
At present days most vehicles contains only the tires as the elastic element
between vehicles and road, where tires sometimes fail to deliver appropriate
suspension features. However, some recent vehicles are developed with the different
types of suspension; those include simple seat suspension with improved chassis
suspension. This types of suspension is capable of improving only the passenger
2
comfort, however, chassis suspension provides satisfactory road performance with the
quality ride of vehicles.
A suspension system of vehicles is one of the main research works for many
researchers nowadays. Recent works on suspension systems provides ride comfort and
stability with reduction of vibration. However, there was still a need to improve the
quality of design and control of suspension systems which offers more reliability in
terms of ride performance. Various inventions have been adopted to cope up with
vibration in the past. One of them is semi-active magnetorheological (MR) damper.
There are several works have been introduced to reduce vibration but still there is
various way to reduce it more in a flexible and reliable methods.
The efficiency of semi-active vehicle suspension is very well known to
stabilize the whole car body. In order to achieve ride comfort and drive safety, the
idea of MR damper controlled suspension systems is implemented recently. This idea
is getting more popular and acceptable with recent advancement of technology,
especially in automotive industry. In this research, the knowledge of semi-active
suspension in quarter car model is considered.
1.2 OVERVIEW OF THE RESEARCH
This section provides a brief idea about the background of the research which includes
semi-active vibration control approach, quarter-car vehicle, MR fluid damper and its
application and controller design. The aim is to orient the history and development of
MR fluid devices and its necessity at the automotive system especially at suspension
development. Main keywords of this research works are discussed to provide the
reader a complete impression about the findings and results of this research.
3
1.2.1 Background of MR damper and its applications
For nearly in two decades, vibration reduction in different dynamic systems has
received huge concern from industry and academic as well. Improving the passenger
comfort and achieving the vehicle stability are the most significant features in
automotive industry to evaluate the performance of the vehicles. In industry and
vehicle application, damper has been used to reduce and absorb vibration. Usually,
spring is used for this purpose as it is easily available in the market. In recent years,
the development of MR damper has increased rapidly due to its larger application and
robustness. A semi-active control damper, MR damper, has recently been well-known
feature in the vibration control of vehicles. Low energy consumption and quick
response make the MR damper so efficient in suspension design. MR fluids are one
kind of controllable fluids and the ability to change reversibly to semi-solids with
manageable yield strength in a magnetic field is main characteristics of MR fluid. It
offers fewer complexes, rapid-response interfaces between mechanical systems and
electrical controls.
Nowadays, the MR fluid damper becomes very attractive components in semi-
active suspension system for its advantageous features. Some years ago, MR dampers
and it applications was proposed for implementation to control vibration of vehicles,
to minimize the damage at building structure due to seismic waves, and for varying
stiffness of sports machineries. MR damper is similar to a standard damper filled with
MR fluid which has electromagnetic wire wrap coils around the piston. MR fluid
contains polarizable material with minute suspended particles that change the
rheological properties drastically when involves in a magnetic field. The particles
remain suspended in the MR fluid and the damper behaves similar to a simple viscous
damper when no current involved in the piston. However, when current is applied,
4
then these particles are organized in a columnar trend with the change of the viscosity
of the fluid and increase of the resistance provided by it to the motion of the piston.
This project focuses on active vibration control, characteristics and the design and
fabrication of the damper itself. MR damper has unique features and characteristics
such as fast response time, dynamic yield strength, temperature resistant and these
make it a better option than conventional damper.
1.2.2 Keywords
The four main keywords discussed in this section are a) Semi-active, b)
Magnetorheological, c) Quarter-car, and d) Controller design.
1.2.2.1 Semi-active
A suspension system is mainly known as active, passive, and semi-active depending
on the amount of external power required for the damping system to perform its
function. Characteristics of the components (springs and dampers) are fixed in passive
suspension systems whereas in an active suspension system, the passive damper or
both passive damper and springs are replaced with force actuator. But in a semi-active
suspension system, conventional spring is retained but the damper is replaced/added to
a controllable damper. Unlike an active suspension system which requires an external
source to power the actuator and control the vehicle, a semi-active suspension system
used the external energy source only to adjust the damping levels and operate an
embedded controller and a set of sensors. The level of damping is controlled by
designed controller and it automatically adjusts the damper to gain required damping.
One of the most semi-active control strategies is Proportional Integral Derivative (PID)
which adjusts the damping level to reduce the vibration level of a vehicle. In case, the
5
controllable damper of semi-active damper fails to provide required damping, it
automatically works as a conventional damper although the failure rate is very low.
Semi-active suspension systems are very less complex, and requires much lower
power compared to active systems.
1.2.2.2 Magnetorheological (MR)
Magnetorheological (MR) fluid is widely known for various purposes in civil
engineering, automotive systems, and safety engineering and so on. Many papers have
been studied to acknowledge the characteristics, properties and applications of MR
fluid. Typical magnetorheological fluids are the suspensions of micron sized,
magnetizable particles (mainly iron) suspended in an appropriate carrier liquid such as
mineral oil, synthetic oil, water or ethylene glycol(Kciuk & Turczyn, 2006). It carried
out that the rheological properties of controllable fluids depend on concentration and
density of particles, particle size and shape distribution, properties of carrier fluid,
additional additives, applied field, temperature and other factors(M. Jolly, Bender, &
Carlson, 1999).
Next few studies will describe about the design and application of MR fluid. A
study shows that MR fluids provide a dynamic yield stress over Electro-rheological
fluids(ER) and wider operational temperature range. Also it shows the application of
MR fluid to vibration control which offers MR damper to control vibration of vehicle
(Ashfak, Saheed, Rasheed, & J. Abdul Jaleel, 2009). Carlson et al. studied the
advantages of MR over ER fluid devices in several areas such as required volume of
fluid, power and the yield strength. Also operational modes of MR fliud are presented
in this paper with addition of linear fluid damper, and the vibration damper (Carlson,
Catanzarite, & St. Clair, 1996). A verification study designed the magnetic circuit of
6
MR devices which works in different operation mode of MR fluid(Bolter & Janocha,
1997).
Another study developed a concept of MR converter and it is applied to create
devices such as MR damper, lnear damper and MR seal which are often used
today(Kordonsky, 1996). Finally, Jolly et al. developed a model to predict the
characteristics of MR fluid and MR elastomer and it is verified experimentally(M. R.
Jolly, Carlson, & Munoz, 1996).
1.2.2.3 Quarter-car
When designing any suspension of a vehicle, generally there types of car model are
used such as full car, half car and quarter car model. A quarter car means 1/4 of a full
car which is widely used to design of a damper in simulation and experiment. Two
degree-of-freedom quarter-car models, based on different types of road excitations are
widely introduced in many areas of automotive industry. This is mostly because of the
simplicity of the quarter-car models and the best correct information they provide,
especially for vehicle handling and passenger comfort. Currently, many researchers
are using the quarter-car models to get the exact information on vibration reduction
and then they can easily apply it to other part of the vehicle.
1.2.2.4 Controller design
When we design a suspension system, controller design becomes a very important tool
to assist the damper offer ride comfort and improved vehicle handling with vibration
reduction. Designing a controller for a suspension system is key tool to assure the
better performance of a vehicle. There are various techniques have been introduced
which are capable of controlling the vehicle system. Proportional Integral Derivative
7
(PID) controller is well known for semi-active suspension system which has the three
(Kp, Ki and Kd) gain parameter to stabilize and improve the overshoot, settling time
of a system. Also a full state feedback controller, Linear Quadrative Regulator (LQR)
is common in controller design of a suspension system. Finally, among other
controllers, Fuzzy and Skyhook controllers are widely used in automotive industry.
Using above control techniques, hybrid controller also developed in recent years.
1.3 LITERATURE REVIEW TECHNIQUE
A literature search was conducted to find out the past research done in the area of my
research interests. The primary interests are the areas of semi-active control strategy,
magneto-rheological damper, quarter-car, controller design, simulation and
experiments on MR dampers on quarter-car. Figure 1.1 shows a flowchart of my
literature review works based on my keywords. Few databases were taken into
account for this search of these research works.
As expected, there are plenty of works done with relevant keywords but some
are repeated with minor changes. Many books and other papers related to vehicle
dynamics, control, and semi-active suspension, MR damper models have been read
and consulted with supervisors in addition to the papers reviewed.
Figure 1.1. Literature Review Flowchart
8
1.4 PROBLEM STATEMENT
Semi-active and MR damper are two important elements in improving ride quality.
The performance of MR damper depends on some key parameter based on MR
properties. Previously, many researchers proposed different models to find the
optimum values of these parameters. The models are tested experimentally to find the
best response separately. But there is no comparison among these models to find the
suitable model which fit semi-active MR damper properly based on the requirements.
A proper investigation is necessary to find best model for semi-active MR damper of
vehicles. However, many researcher also trying to design different controllers to
obtain optimum results, although, few controllers have been proposed already. There
are some key parameters which influence the MR damper‟s performance. There are
some limitations of those control systems which does not have proper response to
reduce vibration of the suspension system. There are so many uncertainties on road
profile.
Therefore this would be a good opportunity to select a suitable MR damper
model to implement at semi-active quarter-car model to design a new control
algorithm which deals with different road excitation to solve the uncertainties of the
road.
1.5 RESEARCH OBJECTIVES
The objectives of this research work are as follows:
1. Evaluating the performance of different control policies numerically and
design an appropriate control policy to suit performance requirements.