1. FACULTY OF ENGINEERING AND ARCHITECTURE
DEPARTMENT OF MECHANICAL ENGINEERING
ACTIVE VIBRATION CONTROL
IN VEHICLE SUSPENSION SYSTEM
A GRADUATION PROJECT
submitted by
Hüseyin Eren MEŞELİ
in partial fulfillment of the requirements for the degree of
BACHELOR OF SCIENCE
MAY 2015
Program: Automotive Engineering

2. i
ACTIVE VIBRATION CONTROL
IN VEHICLE SUSPENSION SYSTEM
A GRADUATION PROJECT
by
Hüseyin Eren MEŞELİ
submitted to the Department of Automotive Engineering of
OKAN UNIVERSITY
in partial fulfillment of the requirements for the degree of
BACHELOR OF SCIENCE
Approved by:
Asst. Prof. Ilker Altay
Supervisor
May 2015
Program: Automotive Engineering

3. ii
ABSTRACT
ACTIVE VIBRATION CONTROL
IN VEHICLE SUSPENSION SYSTEM
Vehicle comfort and driving safety are interesting topics for researchers among
many issues in vehicle dynamics area. In this study, a method for active vibration
control of vehicle vibrations caused by road profile by utilizing a linear actuator in
order to improve drive comfort and safety is proposed.
The system is assumed as a 2 degrees of freedom quarter car suspension model.
Equations of motion of the system are derived by utilizing Newton laws and
Lagrange’s Equation of Motion. After obtaining transfer functions and state-space
representation of the system. A PID and controller are designed for active control of
vehicle vibrations. Performance of the designed controller were investigated by
conducting simulation using Matlab/Simulink software.
Performance of the designed controllers are determined and compared with each
other by using road profile functions.
By comparing the obtained simulation results usability of Matlab/Simulink
software in active vibration control of a quarter vehicle model is also evaluated.
Keywords: Vehicle Suspension System, Vehicle Vibrations, Active Vibration
Control, Controller Design, Linear Actuator, PID Control, Stability

4. iii
KISA ÖZET
TAŞITIN SUSPANSİYONUNDAKİ
AKTİF TİTREŞİM KONTROLÜ
Taşıt dinamiği alanındaki araştırmacıların en çok ilgisini çeken konuların
başında araç sürüş konforunun ve sürüş güvenliğinin sağlanması gelmektedir. Bu
çalışmada, karayolu taşıtlarının sürüş konforunun ve güvenliğinin iyileştirilmesi
amacına yönelik olarak yol yüzeyindeki düzgünsüzlüklerin yol açtığı araç
titreşimlerinin aktif kontrolü için doğrusal eyleyici kullanılan bir yöntem sunulmuştur.
İki serbestlik dereceli bir çeyrek araç modeli olarak ele alınan sisteme ait
matematiksel model Newton yasaları ve Lagrange Hareket Denklemi kullanılarak
elde edilmiştir. Sisteme ait transfer fonksiyonları ve durum-uzay modeli elde
edilmiştir. Taşıt titreşimlerinin aktif kontrolünde kullanmak üzere PID için
tasarlanmıştır. Matlab/Simulink yazılımı kullanılarak yapılan simülasyonlarda
tasarlanan kontrolcülerin performansı incelenmiştir.
Tasarlanan kontrolcülerin yol düzgünsüzlüğü fonksiyonu kullanılması
durumundaki performansı karşılaştırılarak tasarlanan kontrolcünün kullanılabilirliği
irdelenmiştir.
Çalışma kapsamında, Matlab/Simulink yazılımlımından elde edilen simülasyon
sonuçları karşılaştırılarak bu yazılımın aktif titreşim kontrolünde kullanılabilirliği de
değerlendirilmiştir.
Anahtar Kelimeler: Araç Süspansiyon Sistemi, Taşıt Titreşimi, Aktif Titreşim
Kontrolü, Kontrolcü Tasarımı, Doğrusal Eyleyici, PID Kontrol, Kararlılık

5. iv
ACTIVE VIBRATION
CONTROL
IN VEHICLE SUSPENSION
SYSTEM
Name: Hüseyin Eren MEŞELİ

6. v
ACKNOWLEDGMENT
Every stage of my work who helped me, my precious teacher Asst. Prof. Ilker
Altay. Secondly, present to all knowledge about on my student times,
acknowledgment to all of my teachers. Finally, support my education about material
and moral to acknowledgment to my family.
Hüseyin Eren MEŞELİ
Istanbul-2015

7. vi
TABLE OF CONTENTS
ABSTRACT..........................................................................................................ii
ABSTRACT (TURKISH LANGUAGE)...........................................................iii
TITLE OF THESIS.............................................................................................iv
ACKNOWLEDGMENT......................................................................................v
TABLE OF CONTETS.......................................................................................vi
SYMBOLS AND ABBREVIATIONS.............................................................viii
1. INTRODUCTION............................................................................................1
2. SOURCE RESEARCH....................................................................................2
3. MATERIAL AND METHOD.......................................................................10
4. VIBRATION CONTROL ON VEHICLES.................................................11
4.1. Vehicle Suspension Systems by Vibration Damping Properties.........12
4.1.1. Passive Suspansion Systems..................................................................12
4.1.2. Semi-Active Suspansion Systems..........................................................13
4.1.3. Active Suspansion Systems....................................................................15
4.2. Quarter Car Model.................................................................................16
4.2.1. Quarter Car Model With Active Suspansion System.............................17
4.2.2. System Modeling With Newton Motion Equations...............................18
4.2.3. System Modeling With Lagrange Motion Equations.............................18
4.2.4. Linear Transfer Functions Of The System Acquisition.........................20
4.2.5. State-Space Model..................................................................................21
4.2.6. Frequency Of System.............................................................................22
5. CONTROLLER DESIGN............................................................................23
5.1. PID Controller........................................................................................23
6. COMPUTER SIMULATION AND ANALYSIS.......................................26
6.1. Road Roughness Function....................................................................28
6.2. PID Controller........................................................................................28
6.3. Skyhook Modeling..................................................................................30
6.4. System Results........................................................................................31
6.4.1. Sine Wave Road Roughness Results..............................................31

8. vii
6.5. Animation................................................................................................32
6.5.1. Starting Visualization......................................................................32
6.5.1.1. Enabling Visualization for an Entire Model.......................32
6.5.1.2. Visualizing All Bodies in a Machine.................................33
6.5.1.3. Other SimMechanics Visualization Controls.....................33
6.5.2. Using Visualization..........................................................................33
6.5.2.1. Display Versus Animation.................................................33
6.5.2.2. Static Display.....................................................................34
6.5.2.3. Dynamic Animation...........................................................34
7. CONCLUSION AND RECOMMENDATION..........................................34
7.1. Conclusion.............................................................................................34
7.2. Recommendation..................................................................................34
REFERENCES...................................................................................................35
BACKGROUND.................................................................................................40

9. viii
SYMBOLS
𝑴 𝟏: Quarter Car Mass
𝑴 𝟐: Suspansion Mass
𝑲 𝟐 ∶ Spring Constant Of Car Mass
𝑲 𝟐 ∶ Spring Constant Of Car Mass
𝒃 𝟏 ∶ Suspansion System Damping
𝒃 𝟐 : Tire Mass Damping
𝑼 ∶ Control Force
𝑳 ∶ Lagrange Equation
𝑻 ∶ Kinetic Energy
𝑽 ∶ Potential Energy
𝑿 𝟏 : Quarter Car Mass Deflection
𝑿 𝟐 : Suspansion Mass Deflection
𝑾 ∶ Road Profile
𝑲 𝒑 : Proportional Effect Gain Parameter
𝑲𝒊 ∶ IntegraL Impact Gain Parameter
𝑲 𝒅 ∶ Derivative Effect Gain Parameter
ABBREVIATIONS
PID: PROPORTIONAL INTEGRAL DERIVATION

10. 1
1. INTRODUCTION
The output of motor vehicles, even in ancient times, only non-motorized and human or animals
since the use of vehicles pulled by a vehicle over two of the main problems that must be overcome if
the driving safety and driving comfort is maintained. Interested in advances in technology and
transportation of vehicles on the roads, watching the construction technical developments in parallel
with increasing speeds of the vehicles that we use constantly. Increasing the speed at which make
provision for these two criteria is a factor.
A good example of the mechanical systems will have vehicles, as they were watching a road
surface, is very different from its dynamic and frequency values is exposed to vibrations. This
vibration of (which is reflected as a part of the noise) ride comfort and driving safety in order to
ensure effectively the criteria in order to effectively suppress for many different design and control
methods have been developed. This is one of the biggest challenges encountered in the design
process; a great number of relative movement of vehicles is to perform together. One of the most
important problems in the design process ensuring the desired criteria are rendered within a conflict
among themselves. For example, high driving comfort driving safety in order to increase driving
safety, while reducing the interventions are also reduces the driving comfort.
Commuters sensed the vibrations stimulated by different resources. These are; vehicle engine and
drive-train, aerodynamic forces, wheel and is connected to the band's static imbalances and, most
importantly, the irregular of wheels (broken, bumpy) road surface is the interactions. Road surface
defects, can be considered almost as smooth as the freeways which is called very rugged off-road
road surface subjected to different classifications ranging from to. In the body of the vehicle of the
vibrations caused by the road audio part varies some depending on the design and conditions of
work, so the wheel and suspension system of a group of static and dynamic properties of vehicle
inertia forces and vehicle speed determines the amplitude and frequency of the vibrations transmitted
to the range.
All ground transportation and the way to increase driving comfort and driving safety in vibration
suppression of motion passes. Especially off-road (the way external) high amplitude and low
frequency vehicle value, are reflected in the Suppression of vibration to the body, change the way
both the user and the health and safety of the passengers and 2 to maintain the structure of the
vehicle's load and is mandatory. To do this, first of all components of the vibration analysis of
exposure and should be understood. At the same time, vehicle, passengers and cargo carried in the
examination of their answer to the movement and vibrations that are active, and will be in place to
distinguish dominant components. All vehicles are generally 3 pieces lag and 3 rotational vibration
movement despite exposure to these are the most predominant one vertical direction vibration within
transactions.
Publication vibration suppression of systems that are used for the purposes of the movements of
suspension systems in certain fields. a good suspension system providing the criteria that are
expected on the first to design vehicles in a correct manner, and determine the source of the problem
must be defined as specified above. To do this, first you must create an analytical model of the
system is discussed. Then, in case of a criterion people vibration sensitivities should be expressed as
mathematical, similarly road irregularities will be an introduction to this model must be arranged in
such a way. Thus, it is necessary on the system design parameters is discussed, it is possible to
achieve.

11. 2
2. SOURCE RESEARCH
As with all mechanical systems in vehicles in the road or driving both passenger and vehicle
vibrations caused by the way that creates a significant problem for the elements that constitute
it. Karl Benz in Germany in 1886 Manneheim the first we know of our on the movement by car, up
to the present in order to forestall this problem in the process that many studies have been
conducted. For this purpose the solution; a wide range of suspension systems and control method has
been the development of.
There are two main objectives in the design of the suspension system; the first of these may
occur in the structure of passengers ' physical and mental comfort level to minimize the effect of the
provision, and the other is the vehicle's path of contacts with continuity, so a good driving
characteristics. These two features are tightly depending on whether one of the worsening of the
other healing in general terms means that covers it.
In order to be a good suspension system of the vehicle in all suspension parameters and
environmental factors must be known better given how they react. At the same time according to the
system's requirements, if new elements designed to be reinforced or different control methods with
supervision is also targeted.
Material science advances and saved in external energy resources ready to use on the vehicles,
together with the increase in use of semi-active systems can and will be with the constraints
encountered tried active suspension systems. Isermann (1996) the study according to active
suspension systems becomes no longer become an absorber, the actuator. According to Isermann
active suspension systems are the differences to the fluid (hydraulic or pneumatic) is used, the
improved materials (piezoelectric, memory metal etc.) used and electromechanical actuators (motor,
elektromagnet etc.) can be divided in three different groups are used.
Bannatyne (1998), Ikenaga (1999), Nguyen (2001), and Balas (2002) studies made by Fialho;
the actuator structure only hydraulic fluid material used. A system of this type of thing assuming
alone the actuator spring and damper. The actuator is provided by an external app for the amount of
fluid pump. Thus, the value of each group of damping suspension vehicles and vehicle ride height
independently of each other contexts.
Williams (1997b) is the study to a new name of oleo-pneumatic, the actuator structure has
revealed. This actuator type was used with oil and air as the working fluid. The actuator is a kind of
oil in the air compressed by springs illustrates the effect. The effect of the damping oil flow in the
form of absorber.
Ramsbottom and Crolla (1997) have provided room for the pneumatic damper in the
works. This system is called the damping force, bellows in compartments pumping air via the level
control valves or is obtained thanks to the evacuation. Here bellows standard suspension systems,
spring element level control valves is the damping element fulfills the function of.
Demerdash (1995) study of with Ramsbottom and Crolla (1997) study of a similar
structure is seen rather than a standard automobile. At the same time to increase system performance,
correlation with an algorithm called wheelbase model about a prediction also available. This

12. 3
relational front wheels of the rear wheels were subjected to predictive route will remain exposed to a
specific disorder is based on the time delay to disorder the assumption is based. Inc. Figure 2.3
shows how this information can be obtained at. Trials were made thanks to this relational approach
to relational Demerdash approach is the use of active structure based on the value of 20%, body
acceleration of acceleration of the contact (rear wheel group) up to 18% of the value of the
improvements they have achieved. Passive systems are the results obtained with the model in the
same way as compared to is; 44% in value for acceleration of the body of the acceleration of the
contact (rear wheel group) is 29% in value achieved better results.
Figure 2.1. Obtaining the preview information on half vehicle model
Roh and according to Park (1998);the movement of the front wheels is obtained on the basis of
this preliminary tracking information only contributes to the performance of the rear
actuator. However, both the front and rear wheels for this type of information to be obtained whose
performance will be more. Therefore a step beyond front tracking method is to use of the way the
sensors are emerging. As these types of systems, a short distance from radar or optical path sensor
image sensors are used (McConnell, 2001).
Walker (1997) and Donahue (2001) ' the trials were done on a system of this type is placed in the
vehicle in the front part of the sensor as in Figure 2.4 vehicle just in front of the path profile, are
scanning and control algorithm.

13. 4
Figure 2.2. The estimation of the road profile with the addition of road sensor
( Donahue , 2001)
As you can see from sensors, marks obtained by evaluating the vehicle's next step will be exposed
to the path identifies the profile. Thus, both the front and rear suspension system for a front tracking
information is obtained.
In reality a vehicle on the bugger off and unsprung masses between these two block moves in a
different direction by producing damping force will be able to create the effect of each system can be
used as an active actuator. Electromechanical actuator they that constitutes the most beautiful
examples in. For example, they dealt with this in mind Hoogterp (1997) suspension system structure
used an electric motor as actuator. However, the rotational movement of the motor and spin the
wheel to move linear linking directly to the vertical direction of travel to the Group of transactions
remains energized, the çalIşmIşlardIr. This is especially so with the way wheeled armored vehicles
link above, they have achieved satisfactory results.
Weeks (1999) and (2000) as their studies of a DC motor actuator is used again. But unlike her
work of the rotational motion of the engine Hoogterp to implement the system by converting linear
movement. An electric motor in the system with the use of hydraulic system in terms of both the
place according to the acquisition as well as to respond much faster to move in terms of awarding
benefits. The biggest disadvantage of this type of actuator is considering the use of four wheel group
for all the energy needed for the actuator of the system is that it is too much. Weeks and his friends
what they do real experiments have achieved appropriate results as quite decent road, broken way to
confer acceptable levels results in the onsite engagements. However the above mentioned type of
actuator is performed with the structure of active suspension systems, vehicle body vertical
acceleration and displacement and 2.5 times the value of passive systems have achieved better
results.
Weeks and his friends the rotational movement of the linear electric motor in order to bring their
conversion from Holdman (2001). Traditional springs and damper suspension system of passive

14. 5
vertical direction, they have added a moving elektromagnet structure. With this plugin to fix the lack
of damping force of systems.
Vehicles were advancing on the road surface is actually a very complex path profile is exposed to
them. Karaçay (2002) according to a path profile; taken from a virtual line of road surface two-
dimensional cross section is defined as and is as in the following figure.
Figure 2.3. Road Sections (Karaçay 2002)
Gillespie (1992) according to most effective vibration source characteristic of driving vehicles on
the road are available as in Figure 2.3 roughness. This roughness along the route pits, ramps, road
making errors and it consists of characteristics of the materials used.
As a result of the hard work to advance on the path of a rapidly advancing vehicles eliminating
religion represented by the normal distribution. Accordingly; Road roughness experimental
measurements instead of obtaining them, the development of different formulas with results that are
close to the vowel. The idea here is to obtain a general expression for analytical studies have been.
Makes such a purpose as Robson (1979), the first studies of the surface roughness on spectral
density which achieved expression. This work followed by Sharp and is set in of Crolla (1987) three
different road type (roads, main roads, motorways) located in Robson's formula for roughness
coefficient can take value ranges and the average value is given.
Gillespie (1992) is the power spectral density function by improving the roughness coefficient
used in material ways, as well as the value of a coefficient, has added more expression. Gillespie is
an appropriate equation according to random number series used in conjunction with a typical path
for the roughness Tester spectral intensity of expression that produces the results.
Sayers and Karamihas (1998) their attempts to advance wheel trail elevation profile roughness in
the vehicle's vacuum and wide-band random signals are classified as. For this purpose, the way they
expressed with mathematical functions to profile for this purpose in the benefit of the trigonometric
functions. Karamihas is a typical way according to Sayers and profile to resemble a sine curve
directly with a series of sine curve can be divided. Thus, complex-shaped functions mathematically
different wave lengths, amplitudes and phases of sine curve created by substituting together. Path

15. 6
profile, should be added to each other to create sine curves and amplitude discrete fourier transform
with the help of the indices of assets of the stochastic effects of different frequency components
within an event individually revealed.
Up to this point, are advancing on the road vehicles so modeling the movement of vibration of the
studies had given. Subsequent studies have examined the effects of the vibration movements of
people.
This topic is one of Yang (2001), who studies according to these vibrations usually has a complex
structure, many of the components are made from a combination of frequency and can consist of
many different directions over time. Yang publication that incurred some psychological and
biological vibration movement of human-made effects on States.
Griffin (2001a) and (2001b) is in the works that the impact on human health of the movement of
the vibration components worked to uncover. Thus, the human body is one or two frequency value is
sensitive to this frequency and the resonance frequencies of the human body, have stated that as the
values.
Classification of vibration comfort in exposure and human health effects in terms of the
classification is based on the old date even further. The first and most important work in this topic
were made by Janeway (1975). Janeway Carriage House has a single frequency component is
sinusoidal type of extending vertical vibration is exposed to different criteria in terms of comfort and
to limit State charts within. Today, Janeway referred to as Comfort Criteria these criteria are the
Society of Automotive Engineers = SAE is a standard accepted by the implemented as.
A similar type of work carried out by the ISO, the International Organization for Standardization
=.ISO 2631-1 anti-vibration mountings for people whose name published this standard ISO,
exposure time and movement of vibration acceleration depends on the value of the criteria that
determine the boundaries of the stand fatigue or comments (Anonymous, 1997) at the same time is
able to absorb vibration dose of human beings within standard ranges of the path with the
smoothness criteria, which is located in the class.
Exposure to vibration on the human body fatigue is one of the most frequently seen after effects
feel the vehicle motion sickness. ISO publishes standards such as published by the British Standards
with an organization according to the standard for low-frequency = BS and regular exposure to
vibration in vehicle movement gives rise, as Weil (Anonymous 1987). This standard has been
specified in the vehicle is a dose of formula for motion sickness, also depending on the graphics of
the given limit values of frequency.
Taking a physical system in the best way to examine that system the most realistic way of
modeling is very important to what degree it is obvious. Therefore, suspension systems and also on
behalf of the transport system on the model is made in many studies. For example, Williams (1997a)
suspension systems based on the characteristics of passive built-in damping vibrations, semi-active
and active over 3 main groups of the organization. According to Williams's passive systems are the
differences to the traditional arrangement where used suspension systems whether this the elements
characteristic parameter values cannot be changed during driving. With these features, the expected
performance of their own passive suspension systems (transport in the body of the minimum

16. 7
acceleration value in feeling and grip force ensure continuity) always fail. For these reasons the
semi-active and active systems will fail.
Şiren (1996) in accordance with such a system was originally designed, according to the type of
use desirable characteristic parameter values in line with the desired objectives is determined by the
system designers will perform.
AutoZine (2006) according to different road and driving conditions of comfort and safety criteria
in the same way to maintain the vehicle suspension must be exchanged with those of the parameters
contained in the system. For this spring and damping coefficient of the vehicle by the user more
predetermined values, there is a need for the structures that can be set. This type of system the user in
the appropriate path condition (Highway, InterCity roads, bad roads, etc.) or shape of driving (sport,
economic, etc.) according to the originally requested value (soft, medium, hard, etc.) can be adjusted.
This is due to the needs of the semi-active and active systems will fail.
Semi active suspension system it is necessary to implement the kind of damping parameter value
is to update the system with replaceable actuators. Emura and colleagues (1994) is designed to be a
damping coefficient during driving element is bound to the piston in order to perform the rotor
damper from a stepper motor benefited. This is thanks to the return movement of the stepper motor
piston in the valve by changing the width of the stream within the dampener the amount they
changed. However, in this species is an element by using the damper only hard and soft has provided
two different damping value.
Teramura and friends (1997) who follow this work is of the same type as with a damper but the
dampener of hard and soft to the value of that element with a different algorithm that sets the
transition players. In this way, the body of the vehicle feels like acceleration, awarding an
improvement worth.
With an element that is in the same genre Yoshida and colleagues (1999) while the case studies
mounts can accommodate the value for a new design in order to increase the number of stepper
motor have developed. Thanks to his smaller stepper motor moves hard and soft damping were
obtained between the values of the values.
Damping coefficient setting in two different ways this half-active suspension systems, Gordon
and Sharp (1998) will work as stated by on-off and a continuously variable semi-active systems are
divided into two groups in itself to designing and building of satellite. A continuously variable semi-
active systems is active system active system performance close to the values of the basis for the
emergence of. Liu and his colleagues (2005) also works on-off and a continuously variable semi-
active systems, using both continuous variable systems revealed.
The progress in line with the many different damping coefficient for semi-active systems can be
set to the value type of the traditional need to meet with builds power absorber forced. that's why
suspension systems, study the development of material benefit from the right to the use of new
materials were derived. These materials are smart materials.
Pinkos and Shtarkman (1996) compared; smart materials, characteristics that can be controlled,
predictable and observable material class form. Characteristics of these types of materials, such as
electric or magnetic field can be controlled with an external impact and energy material when

17. 8
applied material consists of some predictable and repeatable variations. The solid and liquid forms of
these materials are an example of what happened in the form of solid piezoelectric materials. These
materials can be controlled between electrical and mechanical energy provides an energy conversion
(MSI, 2005). MSI and McConnell (2001) as stated by the piezoelectric effect in the study according
to a named impact this kind of molecule structure is exposed to an electrical field, move the physical
structure change (expansion and shrinkage, etc.) has been observed. Here's the benefit of this effect
different dampers were their designation.
Originally designed by Thirupathi and Naganathan (1995) Piezoelectric ceramic by linking macro
sizes of successive structures vibration they stopped on experimental designs suppress the
movements. Very low response times although not performing perfectly with high voltage could not
be passed to the application because of the need for this experimental structures. However, in parallel
to this work with high frequency piezoelectric materials vehicle noise and vibration suppression of
applications mainly to cattle (Anonymous 2006a).
Suspension system used in the liquid phase is a good example of smart materials in Rheological
liquid. These are the energy field changes when an energy field with variable fluid flow properties
(viscosity) (Jordan and Shaw 1989) along with the implementation of an energy field in a form that
is specific granules (columns shaped) is increasing the amount of energy required to break them
ranked. This is fluid stickiness strength (viscosity) increases. The region that is removed when the
particles are old returns they will rush.
Pinkos and Shtarkman (1996) according to rheological fluids in this way so that they can absorb
the energy suspension systems available in the damping absorber shows. This idea, which set out
from Chung and Shin (2004) electro-rheological fluid contains a semi-active damper designed
it. Apply an electric field in the app for this structure damper valve between the observed flow is part
of a larger movement of resistance provided, i.e. apply the damping force event for the electric field
could be changed with.
The same principle applies where another study (Anonymous 2006b) is used instead of magneto-
rheological fluid-liquid electrorheological. This type of damper is like in the illustration app for
material structure.

18. 9
Figure 2.4. Rheological fluid is used as damping fluid structure (Anonymous , 2006b)
Fischer and Isermann (2004) study of the passive system with a detailed comparison between the
performance of semi-active system. Accordingly; the structure similar to that used with a damper
fluid rheological semi-active suspension system of the passive components used in a suspension
system in terms of ride comfort, driving safety, in terms of 20-30% 10%-25% better results are
obtained. Active suspension systems, while these rates only and only 30% > for ride comfort and
driving safety, for which stands out to 25%. As a result, simple structures requiring an external
source of energy, and very little with semi-active suspension systems are actually pretty good offers
performance values.
As with all systems, suspension systems also require an audit which determines the movement of
the structure. To this end, there are many different suspension control method has been
developed. One of the most widely known method is a method of suspension control on Skyhook.
Emura and colleagues (1994) in their studies according to their recognition; ideal skyhook
suspension control, suspension damper in vehicle body with the same speed of the mobile and
connected between a fixed suspended in the air, are considered to be the hypothetical point is based
on an imaginary suspension model. Still according to this type of mounting damper Emura and
friends of ordering the mass has the same place, so in a way that is independent of the vehicle in the
road surface means advancement.
In practice, a reference point for the skyhook damping levitation can be connected with the body
of the damper between the wheel group as there is no installed vehicle. This new damping force
damper required is practiced by skyhook (Ahmadian 2001). Skyhook suspension control, the body of

19. 10
the vehicle from the road are applied in order to insulate from impact. Ahmadian study at the same
time isolated from the road wheel group effects that groundhook suspension from control is also
mentioned. Groundhook suspension control is similar in principle to skyhook control. It's not in the
air, unlike damper is a reference point on the surface of the ground is connected to the virtual.
Ahmadian (2005) another study is skyhook and groundhook control brings together the
advantages of Hybrid of suspension from the control that is also mentioned. This control method in
both a skyhook is a groundhook damper. Ahmadian study also is used to determine the weight of the
hybrid control method of function linear has also an expression.
Hwang (1998) with Hong (2002) what they do work better on some changes to the control
structure increasingly skyhook performance worked to get. In addition to the adjustable damping
coefficient skyhook dampener, they have added one more, then the damping coefficients of this
damper route entry thinking as a function of control input signal has addressed as follows.
Skyhook control method as an example of studies except for Kuo and Li (1999) 's work, it is
possible to give. Kuo and Li have the reputation they have opted to use a viscosity for a hydraulic
actuator, the actuator will generate the data obtained via the path and force of vehicles of genetic
algorithms and fuzzy logic is used in conjunction with an audit, carried out with the method.
Optimal control strategy is another investigated suspension control method has been the subject
of. Optimal control theory, a mathematical optimization algorithms where used suppliers of audit
policy area. This theory; the values defined for a system that addressed the detainees to be minimized
is based on needs work.
Theory of optimal control for suspension systems it is possible to implement. To do this, first of
all, must be put into the performance criteria of the suspension system. Sam (2000) with Gao (2006)
by four criteria, this is the most important; ride comfort, driving safety, suspension study 14 as the
power range and damper sorted. Of these, the last three in reality only consists in delimiting
criterion, only the first is owned by the system, minimizing the need to be seen. Sam and according
to your friends; When designing a suspension system for the control law reintroduced, "last three
performance criteria for vertical direction while keeping the desired value ranges body acceleration
value try to minimize" should be in the form of.
Roh and Park (1998) with He and McPhee (2005) in the light of these criteria in a vacuum and the
purpose of the optimal value function, value of this function as control strategies in minimizing
trying to put it on the Internet. He and McPhee (2005), with appropriate weighting coefficients of
LQG (Linear Quadratic Gaussian) algorithms using the passive system with the resulting
acceleration of the body approximately 30% reduction in value for society. Within its own developed
and genetics, LQG, and Kalman filter algorithms combining two different methods such as A-I-O
(All in One) in the fuselage again with algorithm acceleration of the passive system is 50% and 65%
reduction provided.
3. MATERIAL AND METHOD
Today it is practiced mainly in passive vibration control of road vehicles. Passive vibration
suppression of the vibrations of the vehicle suspension systems controlled function was provided by
traditional mounts. However, in recent years, the additional energy requirements in road vehicles and

20. 11
one or more who need the actuator requires the use of active vibration control research are
increasingly gaining currency. The scope of this thesis active vibration suppression of vibrations in
systems of vehicles in order to increase vehicle body with the castrated wheel group will be added to
a linear actuator. Thus, an additional viscous damping force in the system damping force will be
included, the system will become an active vibration-controlled suspension system.
Within the scope of the thesis is primarily a 2-DoF vehicle model will be created a quarter of road
vehicles, to perform active vibration control of a model linear servomotor will be placed. Figure
3.1. the mathematical model of active vibration control system also seen after ms mass by controlling
vibrations that belongs to the driving comfort and grip you will develop the controller will be
designed. It is estimated that PID controller must be developed. MATLAB/Simulink environment
and compare it to the performance will be developed with the availability of scrutiny this controller.
Figure 3.1. The active vibration control system is created by adding a linear servomotor
Vehicle-road interaction will be held to examine the computer simulation is commonly used in
sinusoidal, step function, to be used in non-uniform way in the form of a trapezoid function.
4. VIBRATION CONTROL OF VEHICLES
Highway vehicles off the road or driving the vibrations resulting from driving safety for
suspension systems to suppress without reducing benefits. These systems are all different even
though the formation of the property as a result serves the same purpose. Suspension systems by
placing the wheel on the body of the vehicle with the vehicle is among the group of effects resulting
from reduced vibrations were worked. However these systems are different tasks at the same time
fulfill them. Car suspension systems, tasks are ordered as follows:
 Working together with the wheels during driving passengers or improve the driving comfort
and protect the load being moved in order to originate from the surface of the road vibrations,
oscillations and sudden shock by absorbing the quash or softened. Thus, also the chassis and
bodywork are also preserved.

21. 12
 In vehicle mass on the axles and variable conditions this provides a geometric balance
between the two.
 Wheels and ensures that any contact between the road and the vehicle safe by providing him
a certain fixed strength maneuvers (turns, change lanes, the sudden stop and departures etc.)
don't allow.
 The road surface and the wheels depending on the friction that occurs between driving and
braking forces, consisting of forwards into the body of the vehicle.
Obviously the main purpose of damping of suspension systems is to perform the action. This
damping properties according to suspension systems it is possible to classify it in themselves.
The vibrations originating from the road or driving the way damping based on the characteristics
of vehicle suspension systems 3 main groups covered:
 Passive Suspansion Systems
 Semi-Active Suspansion Systems
 Active Suspansion Systems
4.1. Vehicle Suspension Systems by Vibration Damping
Properties
4.1.1. Passive Suspansion Systems
A passive suspension system characteristic values is fixed and do not change these values during
the course of transport elements (i.e., the traditional spring and damper) consists of. These
characteristic values are system designers by vehicle design during the desired objectives (ride
comfort and driving safety) are determined and accordingly will perform the installation on the
vehicle. Passive suspension systems, at this point the only way element values are modified, the new
value inserted into the application system that carries.
Figure 4.1. Passive Suspansion System

22. 13
Figure 4.1. as in a passive suspension system storing the energy spread and damping by means of
distributing that energy also has the ability to. This structure; vehicle body and suspension system
that represents a block of sprung mass and unsprung mass representing the wheel consists of the
fasteners. The spring coefficients k and damping coefficients are represented with the letter c, and if
this parameter values cannot be changed during driving.
Suspension system for generation, you could carry the whole load on the way once the effect of
the desired back after you select will provide damping spring damper coefficient determination
remains. System for a small damping coefficient is selected;with spring and unsprung mass has the
natural disorder of a way I'm matching their frequency with the body of the vehicle when exposed to
resonant movements observed. In contrast to the high-frequency component from the road provides
good insulation. If a large damping coefficient is selected; the reverse shows the reduction in
resonance.But however it provides less insulation against high-frequency vibrations. That is being
felt more in the body of the vehicle vibrations.
Different road and driving conditions of comfort and safety criteria in the same way to maintain
the vehicle suspension must be exchanged with those of the parameters contained in the
system. However, the passive suspension systems, these parameters cannot be modified vehicle-
producing company, the appropriate path condition (Highway, InterCity roads, bad roads, etc.) or
shape of driving (sport, economic, etc.) according to the originally requested value (soft, medium,
hard, etc.) uses elements.
4.1.2. Semi-Active Suspansion Systems
Made during the creation of passive vehicle suspension systems, suspension system can be done
during the process of the selection of the parameters of looking half-active suspension system
constitutes the reason for the emergence of. These types of systems, passive spring element where
the damping coefficient can be adjusted from the outside mounts, while preserving the models
changed. However, the passive suspension system does not present an action, such as Exchange
parameters in this process, there is no need for an extra energy source for half-active suspension
systems, damping coefficient of tuning and controller systems to run the sensors with an external
power source is needed.
Figure 4.2. Semi-Active Suspansion System

23. 14
Figure 4.2. the structure as shown in the given system; semi active suspension systems, unlike the
passive system damping force adjustable damper is available in the system. Required damping force,
sensors by means of using the data collected through control strategy of vehicle determined to
calculate by the controller and damper of substances required for sending this marks the damping
coefficient can be arranged.At this point, the important thing is that the damping damping force of
interfacial and mounts the relative speed (vehicle body and wheel group speeds differ) depending on
the facing.
Half the value of the damping coefficient modification active damping systems can be addressed
in two separate groups according to the range. For damping coefficient change charts illustrate in
Figure 4.3.
 On - off semi-active suspension systems
 Continuously variable semi-active suspension systems
Figure 4.3. Range of damping coefficient for semi- active suspension system
a.on - off and b. for continuous variables systems
In the previous figure, depending on the relative speed damping force damper charts given that
half-active suspension systems, the first open – closed in structure; According to the criteria
determined by the damper control algorithm, either open or closed location is mentioned. When the
open position as shown in Figure 4.3a. hard (high) damping of Interfacial artistry. When closed
position is soft (low) is a damping coefficient. Under ideal conditions while in closed position
damping coefficient must be zero, but in practice it does not able to provide this value taken as the
smallest coefficient may be provided.
Continuously variable structure is open – closed as with damper in open or closed positions are
referred to.But while the damper in the open position, the structure of different damping coefficient
values designed to provide. Figure 4.3b chart the shaded part shows the range of damping coefficient
can accommodate different values.According to the criteria determined by the damper control
algorithm, shadowed the section represented by a dashed line can be adjusted to one of the values of
the damping coefficient.
Figure 4.3b. as shown in the shaded area outside with semi-active system damping values cannot
be obtained.

24. 15
Semi active suspension systems, as shown in Figure 4.3 graph every required damping coefficient
value of the damping force of the reasons and still obtain the vehicle body and wheels should be
dependent on the movement of the Group caused by restrictions on active suspension systems by
means of and will be studied.
4.1.3. Active Suspansion Systems
Active suspension systems, and the use of passive systems on the type of damping spring element
according to the shape of the sometimes protects completely from the system sometimes where the
body is. Damping coefficient adjustable leaves the damper actuator but functionally brought one
too. Active suspension systems, the actuator; energy-dependent entirely on an external resource, but
a non-dependent damping force vehicle movements is a source. ARC does not contain all of the body
weight in transport figure also be evened out by the actuator. As a result, there is a need for even
more energy can go up.
As mentioned above, the actuator according to the shape of the type and use of active suspension
systems are available in different models. Figure 4.4. shows the two different model structure.
Figure 4.4a. vehicle body is supported by the spread in the system. Thus, the weight of the body is
balanced static conditions. The actuator only way and driving force of the movement caused by the
manner in which to suppress damping is used in order to create. Figure 4.4b. is situated just between
the actuator of the unsprung mass and spring. The weight of the body of both vehicles with the force
produced by the actuator moving and get in front of the vibrations resulting from vehicle movement
seeks to. Suspension system as this model is the preferred publication at the same time, it is possible
to adjust the height of the vehicle floor. Thus, the type of road (Highway, InterCity roads, off-road)
or driving to the shape of (economy, comfort, sporty) according to election bodies vehicles more
comfort and driving performance can be achieved.
Figure 4.4. Active Suspansion Systems a. spring supporter model b. full active model
Active suspension systems have brought performance gains because of an external energy source,
despite the requirement that vehicles using this type of suspension system can't afford not to a cost
increase and may cause a complex structure. However, emerging technology, falling costs and also
in combination with simplified observed.

25. 16
4.2. Quarter Car Model
The simplest structure suspension model are 2-DoF quarter is seen in Figure 4.5 vehicle model. In
this model all the vehicles weight spring indicated mass 𝑀1 1/4 is equal to. 𝑀2 is unsprung mass
indicated by the wheel and the consequent axle group weight. k coefficients a and b are coefficients
in displacement and, respectively, while damping coefficients. 𝑋1 and 𝑋2 is the influence of the
vertical direction of the W route entry, they switch places. Investigation of the movement of the
vehicle in vertical direction vibration model is sufficient for.
Figure 4.5. Vehicle suspansion system of quarter model
2-DoF quarter seen on vehicles model parameters is as follows:
Table 4.1. Suspansion System Parameters
𝑴 𝟏 Sprung Mass
𝑴 𝟐 Unsprung Mass
𝑲 𝟏 Suspansion Spring Constant
𝑲 𝟐 Tire Spring Constant
𝒃 𝟏 Suspansion Damping Value
𝒃 𝟐 Tire Damping Value
𝑼 Control Force

26. 17
4.2.1. Quarter Car Model With Active Suspansion System
Passive vehicle suspension system with suppression of vibrations in the quarter function is
provided by conventional damper. Adjusting the damping force on this model, the vibrations of the
system to increase the ability to suppress in order with spring and unsprung mass do not insert
(vehicle body between the wheel group) can be made of the addition of an actuator. Thus provided
an additional damping force and the system becomes an active suspension system. The actuator after
addition of the quarter vehicle model is in Figure 4.6.
Figure 4.6. Active suspansion of quarter car model
As you can see this new model has been the existence of traditional mounts. In this way the
actuator has an amount of overhead decreases. In moments the shortcomings of conventional damper
actuator with damping force produced by sticking an extra suspension system increases the ability of
the suppression of vibrations.
Table 4.2. Active Suspansion System Parameters
𝑴 𝟏 Sprung Mass 250 kg
𝑴 𝟐 Unsprung Mass 80 kg
𝑲 𝟏 Suspansion Spring Constant 16000 N/m
𝑲 𝟐 Tire Spring Constant 160000 N/m
𝒃 𝟏 Suspansion Damping Value 1000 Ns/m
𝒃 𝟐 Tire Damping Value 0 Ns/m
𝑼 Control Force N

27. 18
4.2.2. System Modeling With Newton Motion Equations
Physical model of mathematical expressions in order to obtain the first of all vehicles in the
model force balance based on motion equations to create required.
𝑀1 𝑋1
̈ = −𝑏1(𝑋̇1 − 𝑋̇2) − 𝐾1( 𝑋1 − 𝑋2) + 𝑈 (4.1)
𝑀2 𝑋2
̈ = 𝑏1(𝑋̇1 − 𝑋̇2) + 𝐾1( 𝑋1 − 𝑋2) + 𝑏2(𝑊̇ − 𝑋̇2) + 𝐾2( 𝑊 − 𝑋2) − 𝑈 (4.2)
Figure 4.7. Degree of Freedom diagrams
As we have seen, active suspension system consists of two linear equations comes from. The
system has two separate transactions for the 2-DoF the equation has been found.
4.2.3. System Modeling With Lagrange Motion Equations
The equations of motion of a dynamic system, there must be a general approach for the Lagrange
formulation is used. Lagrange equations of motion "L" system potential energy and kinetic energy of
the "V" is defined as the difference between the "T".
𝐿 = 𝑇 − 𝑉 (4.3)
The sum of the kinetic energies of the mass;
𝑇 = 𝑇 𝑀1
+ 𝑇 𝑀2
(4.4)
𝑇 =
1
2
𝑀1 𝑋̇1
2
+
1
2
𝑀2 𝑋̇2
2
(4.5)
The sum of the potential energy of the spring elements;
𝑉 = 𝑉𝐾1
+ 𝑉𝐾2
(4.6)
𝑉 =
1
2
𝐾1(𝑋1 − 𝑋2)2
+
1
2
𝐾2(𝑋2 − 𝑊)2
(4.7)

28. 19
The sum of the heat into energy damping elements;
𝑃 = 𝑃𝑏1
+ 𝑃𝑏2
(4.8)
𝑃 =
1
2
𝑏1(𝑋̇1 − 𝑋̇2)2
+
1
2
𝑏2(𝑋̇2 − 𝑊̇ )2
(4.9)
The difference in the total kinetic energy and potential energy;
𝐿 =
1
2
𝑀1 𝑋̇1
2
+
1
2
𝑀2 𝑋̇2
2
−
1
2
𝐾1( 𝑋1 − 𝑋2)2
−
1
2
𝐾2(𝑋2 − 𝑊)2
(4.10)
First equation of system;
𝑑
𝑑𝑡
(
𝜕𝐿
𝜕𝑋̇1
)− (
𝜕𝐿
𝜕𝑋1
) +
𝜕
𝜕𝑋̇1
= 𝑈 (4.11)
𝜕𝐿
𝜕𝑋̇1
= 𝑀1 𝑋̇1 (4.12)
𝑑
𝑑𝑡
(
𝜕𝐿
𝜕𝑋̇1
) = 𝑀1 𝑋̈1 (4.13)
𝜕𝐿
𝜕𝑋̇1
= −𝐾1 𝑋1 + 𝐾1 𝑋2 (4.14)
𝜕𝑃
𝜕𝑋̇1
= 𝑏1 𝑋̇1 − 𝑏1 𝑋̇2 (4.15)
Second equation of system;
𝑑
𝑑𝑡
(
𝜕𝐿
𝜕𝑋̇2
)− (
𝜕𝐿
𝜕𝑋2
) +
𝜕𝑃
𝜕𝑋̇2
= −𝑈 (4.16)
𝜕𝐿
𝜕𝑋̇2
= 𝑀2 𝑋̇2 (4.17)
𝑑
𝑑𝑡
(
𝜕𝐿
𝜕𝑋̇2
) = 𝑀2 𝑋̈2 (4.18)
𝜕𝐿
𝜕𝑋1
= −𝐾1 𝑋1 + 𝐾1 𝑋2 + 𝐾2 𝑋2 − 𝐾2 𝑊 (4.19)
𝜕𝑃
𝜕𝑋̇2
= 𝑏2(𝑋̇2 − 𝑊̇ ) − 𝑏2(𝑋̇1 − 𝑋̇2) (4.20)

29. 20
Lagrange is located after the last equations are;
𝑀1 𝑋1
̈ = −𝑏1(𝑋̇1 − 𝑋̇2) − 𝐾1( 𝑋1 − 𝑋2) + 𝑈 (4.21)
𝑀2 𝑋2
̈ = 𝑏1(𝑋̇1 − 𝑋̇2) + 𝐾1( 𝑋1 − 𝑋2) + 𝑏2(𝑊̇ − 𝑋̇2) + 𝐾2( 𝑊 − 𝑋2) − 𝑈 (4.22)
As we have seen, active suspension system consists of two linear equations comes from. The
system has two separate transactions for the 2-Dof the equation has been found.
4.2.4. Linear Transfer Functions Of The System Acquisition
Linear transfer function of the system is the first to find the equations of the system as we should
have on the implementation of the Laplace transform. If we take the Laplace transform of the
equation system for both input and output that indicates the relationship between transfer function,
we have achieved.
( 𝑀𝑆 𝑠2
+ 𝑏1 𝑠 + 𝐾1) 𝑋1( 𝑠) − ( 𝑏1 𝑠 + 𝐾1) 𝑋2( 𝑠) = 𝑈(𝑠) (4.23)
−( 𝑏1 𝑠 + 𝐾1) 𝑋1( 𝑠) + (𝑀2 𝑠2
+ ( 𝑏1 + 𝑏2) 𝑠 + ( 𝐾1 + 𝐾2))𝑋2(𝑠) = (𝑏2 𝑠 + 𝐾2)𝑊(𝑠) − 𝑈(𝑠) (4.24)
[
( 𝑀1 𝑠2
+𝑏1 𝑠+𝐾1) −( 𝑏1 𝑠 + 𝐾1)
−( 𝑏1 𝑠+𝐾1) (𝑀2 𝑠2
+ ( 𝑏1 + 𝑏2) 𝑠( 𝐾1+𝐾2))
] [
𝑋1(𝑠)
𝑋2(𝑠)
]=[
𝑈(𝑠)
( 𝑏2 𝑠 + 𝐾2) 𝑊(𝑠) − 𝑈(𝑠)
] (4.25)
A = [
( 𝑀1 𝑠2
+𝑏1 𝑠+𝐾1) −( 𝑏1 𝑠 + 𝐾1)
−( 𝑏1 𝑠+𝐾1) (𝑀2 𝑠2
+ ( 𝑏1 + 𝑏2) 𝑠( 𝐾1+𝐾2))
] (4.26)
∆= 𝑑𝑒𝑡 [
( 𝑀1 𝑠2
+𝑏1 𝑠+𝐾1) −( 𝑏1 𝑠 + 𝐾1)
−( 𝑏1 𝑠+𝐾1) (𝑀2 𝑠2
+ ( 𝑏1 + 𝑏2) 𝑠( 𝐾1+𝐾2))
] (4.27)
∆= (𝑀1 𝑠2
+𝑏1 𝑠+𝐾1)(𝑀2 𝑠2
+ ( 𝑏1 + 𝑏2) 𝑠( 𝐾1+𝐾2)) − ( 𝑏1 𝑠+𝐾1)( 𝑏1 𝑠+𝐾1) (4.28)
[
𝑋1(𝑠)
𝑋2(𝑠)
] =
1
∆
[
(𝑀2 𝑠2
+ ( 𝑏1 + 𝑏2) 𝑠( 𝐾1+𝐾2)) ( 𝑏1 𝑠 + 𝐾1)
( 𝑏1 𝑠 + 𝐾1) (𝑀1 𝑠2
+𝑏1 𝑠+𝐾1)
][
𝑈(𝑠)
( 𝑏2 𝑠 + 𝐾2) 𝑊(𝑠) − 𝑈(𝑠)
] (4.29)
[
𝑋1 (𝑠)
𝑋2 (𝑠)
] =
1
∆
[
(𝑀1 𝑠2
+𝑏1 𝑠+𝐾1) ( 𝑏2 𝑏1 𝑠2
+ ( 𝑏1 𝐾2+𝑏2 𝐾1
) 𝑠 + 𝐾1 𝐾2
)
−𝑀1 𝑠2
(𝑀1 𝑏2 𝑠3
+ ( 𝑀1 𝐾2+ 𝑏1 𝑏2)𝑠2
+ ( 𝑏1 𝐾2+𝑏2 𝐾1
) 𝑠 + 𝐾1 𝐾2
)
] [
𝑈(𝑠)
𝑊(𝑠)
] (4.30)
𝐺1(𝑠) =
𝑋1(𝑠)−𝑋2(𝑠)
𝑈(𝑠)
=
( 𝑀1+𝑀2) 𝑠2+𝑏2 𝑠+𝐾2
∆
(4.31)
𝐺2(𝑠) =
𝑋1(𝑠)−𝑋2(𝑠)
𝑊(𝑠)
=
−𝑀1 𝑏2 𝑠3−𝑀1 𝐾2 𝑠2
∆
(4.32)

30. 21
4.2.5. State-Space Model
Active suspension system is a form of a notation system other that defines the dynamics of State
space model. State variable model of the underlying the dynamic condition of the system at any time,
the concept of the State of the system and is fully is to be defined. Case, 𝑋1(𝑡), 𝑋2(𝑡).. . 𝑋 𝑛(𝑡) state
variable with expression. Entries with status of the system's future status variables documentation the
status allows the presence of the equation.
𝑀1 𝑋1
̈ = −𝑏1(𝑋̇1 − 𝑋̇2) − 𝐾1( 𝑋1 − 𝑋2) + 𝑈 (4.33)
𝑀2 𝑋2
̈ = 𝑏1(𝑋̇1 − 𝑋̇2) + 𝐾1( 𝑋1 − 𝑋2) + 𝑏2(𝑊̇ − 𝑋̇2) + 𝐾2( 𝑊 − 𝑋2) − 𝑈 (4.34)






























































































































W
U
M
K
MM
bb
MM
M
Y
Y
X
X
M
K
M
K
M
K
M
K
M
b
M
b
M
b
M
b
M
b
M
K
M
b
M
b
M
b
M
b
MM
bb
Y
Y
X
X
2
2
21
21
1
1
1
1
1
2
2
2
1
1
1
2
2
2
2
2
1
1
1
2
2
1
1
1
1
2
2
2
1
1
1
1
1
21
21
1
1
1
1
0
11
1
0
00
10
0
0010
(4.35)
    






















W
U
Y
Y
X
X
Y 000100
1
1
1
1
(4.36)





















































0
K
0
10
0
0010
2
2
2
1
1
1
2
2
2
2
2
1
1
1
2
2
1
1
1
1
2
2
2
1
1
1
1
1
21
21
MM
K
M
K
M
K
M
b
M
b
M
b
M
b
M
b
M
K
M
b
M
b
M
b
M
b
MM
bb
A
(4.37)
𝐵 =
[
0 0
1
𝑀1
𝑏1 𝑏2
𝑀1
1
𝑀1
+
1
𝑀2
−𝐾2
𝑀2 ]
(4.38)
 0100C (4.39)

31. 22
 00D (4.40)
4.2.6. Frequency Of System
Frequency response analysis of linear, time-invariant systems relevant to earn an important
control systems Designer design concept.
Frequency response, sinusoidal input and output between the signals amplitude and phase refers
to the structure. Frequency response analysis of sinusoidal input signal and noise constant regime of
systems that contain the answer (answer system) helps to identify. Stability analysis of the system of
feedback in the size determination also frequency, gain and phase provides installed ". This concept
is better, depending on the gain and phase boundaries to obtain the frequency of the systems aimed at
changing the answer held control design methods have been developed.
The amplitude and phase of a Bode diagram 𝐺(𝑗𝜔) is expressed. Here is a frequency vector that
contains the positive frequencies of 𝜔
Figure 4.8. Bode Diagram of system transfer function

32. 23
5. CONTROLLER DESIGN
In this section we performed to vibration monitoring and controlling a quarter of the active
vehicle model design are described. The system is designed for control of PID controllers, computer
simulations and analysis section of this controller are used as input of road roughness responded that
they are given in the chart control answers.
PID controller is easy and simple. As is well known, PID control technique; proportional (P),
integral (I) and differential (D) is used in a combination of impact and reference input with actual
output from the three parameters that affect the bug between occur. Study of determination of
parameters of PID controller must gain used in the Matlab/Simulink environment optimized and PID
control designs are described in detail.
Figure 5.1. Active vibration control blok diagram
5.1. PID Controller
PID control of three basic control of the impact of the (P, I, D) is formed from the
combination.
PID control of the output and control laws:
𝑚( 𝑡) = 𝐾𝑝 𝑒( 𝑡) +
𝐾𝑖
𝐾 𝑝
∫ 𝑒( 𝑡) 𝑑𝑡
𝑡
𝑜
+
𝐾 𝑑
𝐾 𝑝
𝑑𝑒
𝑑𝑡
(4,1)
or
𝑚( 𝑡) = 𝐾𝑝 (𝑒( 𝑡) +
1
𝑇𝑖
∫ 𝑒( 𝑡) 𝑑𝑡 + 𝑇𝑑
𝑑𝑒
𝑑𝑡
𝑡
0
) (4,2)
is expressed in the form of and transfer function:
𝑚(𝑠)
𝐸(𝑠)
= 𝐾𝑝(1 +
1
𝑇𝑖 𝑠
+ 𝑇𝑑 𝑠) (4,3)

33. 24
is expressed.
Figure 5.2. PID Controller Design
PID control, three basic control of the impact of their superiority in a single unit, which combines
the effect of a control. Integral continuous regime involved in the system error effect resets using
only derivative effect into the effect of the same system, according to PI control relative stability
increases the speed of answer for. According to PID control organ system zero steady state regime
provides a quick answer with error.
PID control is more complex than others, the organ structure, that rate is expensive. Here's 𝐾𝑝,
𝐾𝑖 and 𝐾 𝑑 a good control with an appropriate setting of parameters can be provided. If this is going
to be set in an appropriate manner, the coefficients PID control besides the superb features of doesn't
help.
Design of PID controller for a system to be made when requested, the desire from the system to
obtain the answer:
 Finding open loop system response and for improving the system response
determination to what you need
 The addition of control system for the development of its time proportional to the
elevation
 The reduction of the amount of the maximum phase system to check the derivative be
added
 Continuous addition of integral system for deleting the regime failure control
 Until the appropriate answer to 𝐾𝑝, 𝐾𝑖 and 𝐾 𝑑 must be set to the values of earning
Finally, for example, make the most appropriate response for the system, with the effect of
the system with integral control PD extra, there is no need. Most of the system's behavior to that
control the system amending the best optimal control.
In order to obtain a good performance from a control system for controlling the most must be
set in the appropriate format. Depending on the type of body control, proportional to the gain
𝐾𝑝, the integral and derivative gains of 𝐾 𝑑's gain of 𝐾𝑖 optimally method, which enables the

34. 25
setting are available. Knowledge representation of the system characteristics of controlled
approximately 𝐾𝑝, That should be set to values of 𝐾 𝑑 and can be determined. This is the
ultimate values of parameters in the dynamic behavior of a continuous regime of the system.
In General, analytical and experimental control organ of the setting to be available in
two ways. Check the body type, measuring element must be known to the dynamic
behaviour of the system and check the control organ type according to the parameters of
the 𝐾𝑝, 𝐾𝑖 and 𝐾 𝑑 are available from the optimum value can be calculated
analytically. This is used in a number of optimization criteria in calculations. Accounts
although transactions possible technical aspects quite complicated and difficult. Even in
simple computer solutions and if you need a type of digital or analog calculator methods
are used. More complex analytical way and control organ of the setting is long, more
experimental methods are used in applications.
In this study, the different way rough quarter of a vehicles suspension system for active
vibration control using PID controllers. Made in order to examine system performance
simulations in two different ways roughness function has been used. The simulations in
Matlab/Simulink/PID Toolbox software is used. PID controller gain parameters of the 𝐾𝑝, and
using the method of trial and error before later PID Kd Toolbox optimization bodies
adjusted. With this approach, 𝐾𝑝 = 9420539.97966783, 𝐾𝑖 = 111358.708912789 𝐾 𝑑 =
31494229.8613296 and That has been achieved in the form of PID controller block diagram of
the system created by using closed-loop Figure 5.1 are given. Accordingly, 𝑋1 − 𝑋2 so the
spring and into the body of the vehicle having the difference in damping as the system output
displacement below. Different ways to functions defined as disruptive entries affecting the
system. Finally, the PID controller output 𝑈 control force as for testing. The obtained
simulation results for the study's Research Results and discussion section is given in detail.

35. 26
6. COMPUTER SIMULATION AND ANALYSIS
In this section, the thesis within the scope of the active controlled vehicle of vibration controlling
designed the success of computer simulation in order to determine and compare the results
interpreted by offering. Computer simulations Matlab/Simulink is made in the
environment. Computer simulations developed primarily for active vibration control system
mathematical model has been obtained, the system MATLAB/Simulink block diagram in the
environment is determined in some ways of the system by creating a non-uniform functions entry at
the bottom of the behavior have been simulated. These simulations use the system to both active and
passive state, behavior and vibration monitoring implemented PID Controller is used in Active status
behaviors were examined, the results are presented in the form of graphs are interpreted. Active
vibration control system block diagram with the Matlab/Simulink environment are given in Figure
6.1 and 6.2 models created.
Figure 6.1. Block Diagram of Active Suspension System (SimMechanics 2015)

36. 27
Figure 6.2. Block Diagram of Passive Suspension System (SimMechanics 2015)

37. 28
6.1. Road Roughness Functions
Figure 6.3. Sine Wave Road Roughness
6.2. PID Controller
Active vibration control system designed for use in the PID controller gain parameters of the
𝐾𝑝, 𝐾𝑖, 𝐾 𝑑 is the most appropriate values for Matlab/Simulink/Control Toolbox/PID Control is
determined by using the software. PID controller block diagram of the system created by using
closed-loop Figure 6.4 is given. Accordingly, 𝑋1 − 𝑋2 as output of the system below the
difference in displacement.

38. 29
Figure 6.4. PID Close Loop Controller
Optimizing the parameters of the PID gain seen in Figure 4.3 PID(s) are made through the
block. This blocks the user Ziegler Nichols method enter manually calculated gain parameters PID
controller design as provided by the control the Tune to optimize the parameters of the command
allows to use. Figure 6.5 optimized via the PID(s) in block.
Figure 6.5. Determined to PID values

39. 30
6.3. Skyhook Modeling
Skyhook controller is simple but very effective control algorithm. It is well known that the
logic of the skyhook controller is easy to implement in the real field. The principle of skyhook
control is to design the active or active suspension control so that the sprung mass is linked to
the sky in order to reduce the vertical oscillations of the sprung mass. Figure 6.6. shows the
conceptual scheme of skyhook controller for vehicle suspension system. The desired damping
force is set by
Figure 6.6. Skyhook Model on vehicle
𝑢 = 𝐶𝑠𝑘𝑦 𝑧̇ 𝑠 (6.1)
where 𝐶𝑠𝑘𝑦 is the control gain, which physically indicates the damping coefficient. In this work,
the value is chosen as 300 using trial-and-error method.

40. 31
6.4. System Results
6.4.1. Sine Wave Road Roughness Results
Figure 6.7. Vehicle body position Blue Active Suspansion Green Passive Suspansion

41. 32
Figure 6.8. Spring Force
6.5. Animation
6.5.1. Starting Visualization
Starting SimMechanics™ visualization requires two choices, one for your entire model, the
second for each machine in your model. These choices are part of configuring your model for
simulation, as discussed in Starting Visualization and Simulation. Implement your visualization
choices at any time by clicking Apply or OK.
6.5.1.1. Enabling Visualization for an Entire Model
You enter the visualization settings for an entire model in the Visualization area of
the SimMechanics node of the Configuration Parameters dialog. To open visualization, you must
select at least one of these check boxes.
Model-wide visualization is turned off by default.
Figure 6.9. Visualization Settings on Simulink option

42. 33
To start visualization, you must select at least one of the first two check boxes:
 Display machines after updating diagram for static visualization
 Show animation during simulation for dynamic animation
Select the Show only port coordinate systems check box if you want to visualize only those Body
coordinate systems with visible ports on their respective Body blocks in the model. The default is
unselected, so that all Body coordinate systems are visualized on their respective bodies.
6.5.1.2. Visualizing All Bodies in a Machine
You can choose whether or not to visualize a specific machine in your model through
the Visualization tab of its Machine Environment block dialog. A single window displays all selected
machines in a model.
By default, each machine is selected for visualization. If you turn off machine visualization, your
choice only affects that machine, not the entire model.
Figure 6.10. Visualization on Machine Environment Blok
6.5.1.3. Other SimMechanics Visualization Controls
All other visualization controls are located on the SimMechanics visualization window itself. You
can access them once the window is open.
You control custom visualization choices for individual bodies in their respective body dialogs
6.5.2. Using Visualization
You can visualize a model using a static display or a dynamic animation.
6.5.2.1. Display Versus Animation
SimMechanics visualization serves two distinct purposes, static and dynamic. In both cases, you can
change your observer viewpoint and navigate through the scene, as well as change the visualized
body properties.

43. 34
6.5.2.2. Static Display
You can display a static state of your model at different stages of modeling. Use static display in the
initial state, during construction. Either:
 Open the visualization before or while you build your model. You display each body as you add it to
your model, if you also update the block diagram.
Having the visualization window open during model building lets you keep track of your model's
bodies and how they are connected. You can see unphysical or mistaken constructions before you
finish the model.
 Open the visualization after you finish the model. All the bodies in the model appear together.
Also use static display after a simulation ends, or after you pause or stop it. In these cases, the
visualization window shows the model at later times or in the final state.
6.5.2.3. Dynamic Animation
You can also display an animation of body motion while the SimMechanics model is running. Use
this feature to watch the model's dynamics in three dimensions and visualize motions and
relationships more easily than is possible with scope blocks alone.
7. CONCLUSION AND RECOMMENDATION
7.1. Conclusion
In this study, road vehicles driving comfort and safety as for the purpose of improving the
road surface caused by non-uniform vehicle vibration active control for linear actuator is used in
a method is presented.
Quarter as system vehicle model mathematical model has been achieved using Lagrange
equation of motion and Newton's laws. System transfer functions and state-space model based
on frequency response of the system after the system of karaklı has been evaluated. Vehicle
vibration active control for PID controllers designed for use. The simulations in
MATLAB/Simulink designed controller performance were studied.
Active vibration control system developed different ways of uneven roads have chosen two
different ways to examine the performance profile. These are respectively the parabolic function
is sine function-form way shaped, profiles.The vehicle has different ways of modeling the
course of non-uniform on the road in order to function in the form of a non-uniform way
intended height against time function.
7.2. Recommendation
In this study, 2-DOF active vibration using linear actuator of a quarter of a vehicle designed
for the control of PID performance of MATLAB/Simulink is explored with computer
simulations made in the environment. After that there's actual path data the way the trials were

44. 35
obtained using the path using non-uniform functions will allow more realistic assessment or
carry.
These simulations use, different vehicle rates are designed to performance of controlling
when using more reliable reviews can be done.
This study was designed under the controlling behavior of experimental simulation computer
simulation results by comparing the experimental simulation and scrutinized bodies computer
simulation results is overridden.
It is modeled on the system used in the system, while also finding the dynamics simulations
in the actuator to reality more affordable models available.
Subsequent studies have shown that the system may be more successful in controlling
different active vibration controllers can be designed. In this context, artificial neural network-
based interval Type-1 and Type-2 fuzzy logic controller and hybrid controllers can be used.
REFERENCES
Ahmadian, M. 2001. Active Control of Vehicle Vibration. In: S. Braun, D. Ewins, S.S. Rao
(Editors), Encyclopedia of Vibration (2002). Academic Press, San Diego, USA. vol.1, p.37-45.
Anonim, 1987. Measurement and Evaluation of Human Exposure to Whole-Body Mechanical
Vibration and Repeated Shock. London, England. British Standart BS 6841.
Anonim, 1997. Mechanical Vibration and Shock - Evaluation of Human Exposure to Whole-
Body Vibration - Part 1: General Requirements. International Organization for Standartization,
Geneva, Italy. International Standart ISO 2631-1.
Anonim, 2002. A Complete Spectrum of Products for Automation Systems Catalog. Parker
Haniffin Corporation, USA.
Anonim, 2004a. Anorad Linear Servo Motors Guide.Rockwell Automation, USA.
Anonim, 2004b. Baldor Servo, Linear & Motion Control Products Guide. Baldor Electric
Company, USA.
Anonim, 2005. Süspansiyon Sistemleri. T.C. Milli Eğitim Bakanlığı, Mesleki Eğitim ve
Öğretim Sistemini Güçlendirme Projesi Ders Notları, Ankara, 2005. 76 sayfa.
Bannatyne, R., 1998. Future Developments in Electronically Controlled Steering and
Suspension Systems. In: R.K.Jurgen (Editor), Electronic Steering and Suspension Systems
(1999), Society of Automotive Engineers, Warrendale-PA, USA, p. 539- 557.

45. 36
Chen, P.C., A.C. Huang, 2005. Adaptive Sliding Control of Non-Autonomous Active
Suspension Systems with Time-Varying Loadings. Journal of Sound and Vibration, p.1119-
1135.
Chung, S.K., H.B. SHIN, 2004. High-Voltage Power supply for Semi-Active Suspension
System with ER-Fluid Damper. IEEE Transactions on Vehicular Technology, vol.53, no.53,
p.206-214.
Demerdash, S.M., 1998. Performance of Limited Bandwith Active Suspension Based on a Half
Car Model, 981118. In: R.K.Jurgen (Editor), Electronic Steering and Suspension Systems
(1999), Society of Automotive Engineers, Warrendale-PA, USA, p. 251-259.
Demerdash, S.M., A.R. Plummer, D.A. Crolla, 1995. Digital Control for Active Suspension
Systems, C498/19/068/95. In: R.K.Jurgen (Editor), Electronic Steering and Suspension Systems
(1999), Society of Automotive Engineers, Warrendale-PA, USA, p. 401-408.
Donahue, M.D., 2001. Implementation of an Active Suspension, Preview Controller for
Improved Ride Comfort. MSc Thesis, The University of California at Berkeley, USA.
Emura, J., S.Kakizaki, F. Yamaoka, M. Nakamura. 1994. Development of the SemiActive
suspension System Based on the Sky-Hook Damper Theory, 940863. In: R.K.Jurgen (Editor),
Electronic Steering and Suspension Systems (1999), Society of Automotive Engineers,
Warrendale-PA, USA, p. 298-306.
Fischer, D., R Isermann, 2004. Mechatronic Semi-Active and Active Vehicle Suspensions.
Control Engineering Practice 12(2004), p.1353-1367.
Gillespie, T.D., 1992. Fundamentals of Vehicle Dynamics. Society of Automotive Engineers
Publications, Warrendale, PA, USA.
Goldner, R.B., P. Zerigian, J.R. Hull, 2001. A Preliminary Study of Energy Recovery in
Vehicles by Using Regenerative Magnetic Shock Absorbers, 2001-01-2071. Society of
Automotive Engineers, 8 p.
Gordon, T.J., R.S. Sharp. 1998. On Improving The Performance of Automotive SemiActive
Suspension Systems Thorough Road Preview. Journal of Sound Vibration, 217(1):163-182.
Griffin, M.J., 2001. Motion Sickness. In: S. Braun, D. Ewins, S.S. Rao (Editors), Encyclopedia
of Vibration (2002). Academic Press, San Diego, USA. Vol.2, p.857-861.
Griffin, M.J., 2001. Whole-Body Vibration. In: S. Braun, D. Ewins, S.S. Rao (Editors),
Encyclopedia of Vibration (2002). Academic Press, San Diego, USA. Vol.3, p.1570-1578.
He, Y., J. McPhee, 2005. Multidisciplinary Design Optimization of Mechatronic Vehicles with
Active Suspensions. Journal of Sound and Vibration, p.217-241.

46. 37
Hong, S.K., H.C. Sohn, J.K. Hedrick, 2002. Modified Skyhook Control of Semi Active
Suspensions: A New Model, Gain Scheduling and Hardware-In-The-LoopTuning. Transactions
of the ASME - Journal of Dynamic Systems, Measurement and Control, vol.124, p.158-167.
Hoogterp, F.B., J.H. Beno, D.A. Weeks, 1997. An Energy Efficient Electromagnetic Active
Suspension System, 970385. In: R.K.Jurgen (Editor), Electronic Steering and Suspension
Systems (1999), Society of Automotive Engineers, WarrendalePA, USA, p. 367-371.
Hwang, S.H., S.J. Heo, K. Park, 1998. Design and Evaluation of Semi-Active Suspension
Control Algorithms Using Hardware-In-The-Loop Simulations. Int. Journal of vehicle Design,
vol.19, no.4, p.540-551.
Isermann, R., 1996. On the Design and Control of Mechatronic Systems - A Survey. IEEE
Transactions on Industrial Electronics, vol.43, no.1, p.4-15.
Jordan, T.C., M.T. Shaw, 1989. Electrorheology. IEEE Transactions of Electrical Insulation,
vol.24, no.5, p.849-878.
Karaçay, T., 2002. Bir Taşıtın Sürüş Karakteristiğinin Durağan Olmayan istatistiksel Analizi.
Yüksek Lisans Tezi, Gazi Üniversitesi, Ankara. 132 sayfa.
Law, A.M., W.D. Kelton, 1997. Simulation Modelling and Analysis. McGraw Hill Higher
Education Pubilication, New Jersey - USA, 544p.
Liu, Y., T.P. Waters, M.J. Brennan, 2005. A Comparison of Semi-Active Damping Control
Strategies for Vibration Isolation of Harmonic Disturbances. Journal of Sound and Vibration,
vol. 280(2005):21-39.
Mcconnell, K.G., 2001. Transducers for Absolute and Relative Motion. In: S. Braun, D. Ewins,
S.S. Rao (Editors), Encyclopedia of Vibration (2002). Academic Press, San Diego, USA. Vol.3,
p.1381-1406.
MSI, 2005a. http://www.msiusa.com/piezo/documentation.asp. Erişim Tarihi: 23.05.2015,
Konu: Energy Generation Using PiezoFilm, Measurment Specialist Inc. USA.
MSI, 2005b. http://www.msiusa.com/piezo/documentation.asp. Erişim Tarihi: 23.05.2015,
Konu: Piezo Film Sensors Technical Manual, part 6-18, Measurment Specialist Inc. USA.
Pinkos, A., E. Shtarkman, 1996. Electronically Controlled Smart Materials in Active
Suspension Systems, 96C004. In: R.K.Jurgen (Editor), Electronic Steering and Suspension
Systems (1999), Society of Automotive Engineers, Warrendale-PA, USA, p. 393-400.
Ramsbottom, M., D.A. Crolla, A.R. Plummer, 1999. Robust Adaptive Control of an Active
Vehicle Suspension System. Proceedings of Institution of Mechanical Engineers, vol.213,
part.D, p.1-17.

47. 38
Ramsbottom, M., D.A. Crolla, 1997. Development and Analysis of a Prototype Controllable
Suspension, 972691. In: R.K.Jurgen (Editor), Electronic Steering and Suspension Systems
(1999), Society of Automotive Engineers, Warrendale-PA, USA, p. 383-391.
Robson, J.D., 1979. Road Surface Description and Vehicle Response. International Journal of
Vehicle Design, vol.1, no.1, p.25-35.
Sayers, M.W., S.M. Karamihas, 1998. The Little Book of Profiling. University of Michigan
Transportation Research Institute Ders Notları, Michigan, USA.
Sharp, R.S., D.A. Crolla, 1987. Road Vehicle Suspension System Design - A Review. Vehicle
System Dynamics, vol.16, p.167-192.
Şiren, M.N., 1996. Bir Yarı Aktif Süspansiyon Sisteminin Tasarımı ve Analizi. Yüksek Lisans
Tezi, Uludağ Üniversitesi, Bursa.
Teramura, E., S. Haseda, Y. Shimoyama, T. Abe, K. Matsuoka, 1997. Semi-Active Damping
Control System with Smart Actuator. New Technologies and New Cars (1997):529-535.
Thirupathi, S.R., N.G. Naganathan, 1995. A New Class of Smart Automotive Active
Suspensions Using Piezoceramic Actuation, 950588. n: R.K.Jurgen (Editor), Electronic Steering
and Suspension Systems (1999), Society of Automotive Engineers, Warrendale-PA, USA, p.
329-339.
Trevett, N.R., 2002. X-by-Wire, New Technologies for 42V Bus Automobile of the Future.
Honors Thesis, South Carolina Honors College, USA.
Walker, G.W., 1997. Constraints Upon the Achievable Performance of Vehicle Suspension
System. PhD Thesis, Cambridge University, England.
Weeks, D.A., D.A. Bresie, J.H. Beno, A.M. Guenin, 1999. The Design of an Electromagnetic
Linear Actuator for an Active Suspension, 1999-01-0730. Society of Automotive Engineers, 11
p.
Weeks, D.A., J.H. Beno, A.M. Guenin, D.A. BREISE, 2000. Electromagnetical Active
Suspension Demonstration for Off-Road Vehicles, 2000-01-0102. Society of Automotive
Engineers, 10 p.
Wickert, J., 2001. Equations of Motion. In: S. Braun, D. Ewins, S.S. Rao (Editors),
Encyclopedia of Vibration (2002). Academic Press, San Diego, USA. Vol.3, p.1324-1332.
Williams, R.A., 1997. Automotive Active Suspensions, Part.1: Basic Principles. Proceedings of
Institution of Mechanical Engineers, vol.211, part.D, p.415-426.
Williams, R.A., 1997. Automotive Active Suspensions, Part.2: Practical Considerations.
Proceedings of Institution of Mechanical Engineers, vol.211, part.D, p.427-444.

48. 39
Yang, B., 2001. Theory of Vibration. In: S. Braun, D. Ewins, S.S. Rao (Editors), Encyclopedia
of Vibration (2002). Academic Press, San Diego, USA. Vol.3, p.1290-1333.
Yoshida, H., K. TANGE, K. MORIKAWA, 1999. Development of Actuator for Suspension
Control. Society of Automotive Engineers of Japan Review vol. 20 (1999):487-492.

49. 40
BACKGROUND
Personal Information
Name Surname : Hüseyin Eren MEŞELİ
Nationality : T.C.
Birth Information : Ankara / 25.01.1992
Phone : +90 (507) 893 8166
Fax : -
E-mail : erenmsl@gmail.com
Education
Degree Name/City Graduation Year
Highschool : Henza Akın Colakoglu Lisesi/Istanbul 2010
Üniversite : T.C. Okan University/Istanbul 2015
Job Experiences
Year Instution Task
2013 T.C. Okan University Internship
2014 Türkiye Taş Kömürü Kurumu Internship
Foreign Language
English(Advanced)