\chapter {INTRODUCTION}
\label{ch:introduction}

 system approach suggesting that a product is a system, which can be obtained by appropriate combination of several simpler subsystems.\\
This thesis concerns  whose purpose is to generate a controlled motion. More precisely, it is deals with mechatronic suspension system. At a highly abstracted level, it is technological components, such as passive suspension mechanism, actuators, sensors and control units, as illustrated in  Figure\ref{fig:mech1}. As the focus of this research is the subject of mechatronic system, hence, this study elaborates on the definition of the concept of “mechatronics” before dealing with the main system under analysis.



\begin{figure}[ht]%Picture plug and calibration sheet
\begin{center}

\centerline{\includegraphics[width=0.9\textwidth]{Chapter1/figure/mech11.png}}
	
	\caption{Mechatronic System} \label{fig:mech1}
\end{center}
\end{figure}

The microcontroller is an essential element in mechatronic systems, and the software content is currently developing rapidly. Mechatronics plays an even more important role for different business sectors such as in industrial products, consumer goods and automotive systems. Moreover, today, the importance of mechatronics is also reflected in higher education, where it has become a degree on its own, being offered in many tertiary education institutions. Commonly, mechatronics courses are not only taught by faculty of one particular discipline, but also jointly by mechanical engineering, electronics and computer science departments . Obviously, it is a subject that transcends the classical boundaries of computer science and engineering.

\begin{equation}
P\left \{ m_j\left ( k+1 \right )\mid m_i \right \}=\Pi_{ij}\left ( k \right )~~,~~\Sigma \Pi_{ij}=1
\label{eq:61}
\end{equation}

A mechatronic approach helps to avoid some of the drawbacks found in conventional systems. As progress in hybrid car requires the researchers to access and improve all modules that compose the car, from low-level mechanical components to high level reasoning systems, this research focuses on mechatronic suspension system to improve ride safety and the handling capabilities.

 
\section{MECHATRONICS:AN OVERVIEW}
\label{sec:review}

engineering which provide the ‘glue’, binding the whole together. This integration is also demonstrated in various diagrammatic forms, which have been employed to represent the structure of a mechatronic system, as illustrated in two examples in Figure\ref{fig:mech2eps}.
\bigskip


 system receives signals from the environment, and processes them to generate new signals, which become inputs to actuating them into forces, movements and actions. The following is an indicative list of topics that are associated with .  

\begin{multicols}{2}
\begin{singlespace}
\begin{itemize}
    \item Machine vision,
    \item Medical systems,
    \item 	Engineering design,
    \item  Automotive engineering ,
    \item 	Automation and robotics,
    \item	Sensing and control systems,
    \item Computer aided and integrated manufacturing,
    \item 	Diagnostics , reliability,  and control system techniques.
\end{itemize}
\end{singlespace}
\end{multicols}

\section{MECHATRONIC SUSPENSION SYSTEM;HISTORY AND A BRIEF BACKGROUND}

As this research deals with vehicle and the road and gives determination about ride safety and the handling capabilities. The suspension system should enable the driver to keep authority over the vehicle in critical situations and provide a high level of ride comfort to prevent physical fatigue of the driver. Furthermore, since the suspension system significantly influences the subjective impression of the vehicle, accordingly the customer demands such as ride comfort and the safety of modern automobiles are constantly increasing. These factors represent the main challenge for the design of vehicle suspension systems.\\
 aspects are taken into consideration. On the one hand, the vehicle should be controllable by the driver to ensure ride safety requiring a stiff, well-damped coupling between the vehicle and the road, especially for non-stationary driving manoeuvres, for example, driving a rough road or cornering. On the other hand , the suspension should provide excellent ride comfort by a soft spring and damper setup isolating the chassis from the road induce

Mechatronic suspensions can ease this conflict by employing controlled force-generating actuators between the chassis and the wheels in case of active suspension systems, or adjustable dampers in terms of semi-active suspension configurations to improve the dynamic behaviour of the suspension.

Figure\ref{fig:mech3}shows a state-of-the-art mechatronic suspension system, which is equipped with continuously variable tegration of high bandwidth actuators in today’s efficiency focused production vehicles.

\begin{align}
\Pi_i=\frac{\frac{1}{\left ( y-y_i \right )^2}}{\sum_{i=1}^{n}\frac{1}{\left ( y-y_i \right )^2}}~~~~~,~~~~~ i=1,...n.
\label{eq:64}
\end{align}


The most important benefit of mechatronic suspension systems is the flexibility provided by the actuator components. If this flexibility is not utilized, i.e. if a time invariant suspension control law is employed, the tuning of the mechatronic suspension cannot deliver optimal results for every driving state. Thus, the full performance potential of the systems cannot be exploited since the requirement to keep the safety limits for different kinds of road profiles introduces conservatism in the controller design. From this observation, the idea to develop a multiple model adaptive control concept has evolved.

\section{PROBLEMS AND CHALLANGES}

In control design process of vehicle mechatronic suspension systems, the uncertainties and nonlinearities of the system are 

existing mechatronic suspension control systems and control design methods, there still exist the following several challenges:




\section{MOTIVATION}

In most active suspension systems, the biggest disadvantage is associated with energy demands. Regarding linear electric 

\section{AIMS AND OBJECTIVES}
The overall goal of this research is to explore the application of modern control techniques to control mechatronic suspension system. In this thesis, optimal PID, LQR, LQG, and $\mu$-synthesis techniques have been used to solve mechatronic suspension system problems. In particular, the research aims to determine whether multiple model adaptive control techniques are appropriate for implementing as controlling algorithms for mechatronic quarter suspension system. This type of investigation is justified in this thesis.



\section{SYNOPSIS OR THESIS ORGANIZATION}\normalsize
This thesis is organized as follows.\\




%\section{THESIS ORGANIZATION} 