Sharif Digital Repository

Through the last decades, due to environmental issues and to confine CO2 emission and also dependency to the fossil fuels, renewable energy resources has been developed. It’s been expected up to 2035, the renewable energy resources will be scaled three times and among those resources, the wind energy will stand prominently. Out of this king of renewable resource, the horizontal wind turbine has been subjected in this research. The focus of is to design the controller in third of a 2 MW turbine operation by which stable rotor speed and nominal output power to be attained. Besides, to enhance the accuracy of the wind turbine profiles, the TURBSIM software (At the National Renewable Energy... 

Best cancer treatment is the one which reduces the tumor density in minimum time and side effects, considering the input limitations. In this paper, tracking controller and robust controllers are designed to achieve the mentioned objectives, simultaneously. An ODE-based mathematical model of the human body under chemovirotherapy is selected, which includes the uninfected and infected tumor cells, free viruses, immune cells, and a chemotherapeutic drug. For tracking purposes, a servo controller based on the entire eigenstructure assignment (EESA) approach is applied to the model, continuously and discretely. For robust purposes H-infinity and D-K iteration approaches are implemented and... 

Through the last decades, due to environmental issues and to confine CO2 emission and also dependency to the fossil fuels, renewable energy resources has been developed. It’s been expected up to 2035, the renewable energy resources will be scaled three times and among those resources, the wind energy will stand prominently. Out of this king of renewable resource, the horizontal wind turbine has been subjected in this research.The focus of is to design the controller in third of a 2 MW turbine operation by which stable rotor speed and nominal output power to be attained. Besides, to enhance the accuracy of the windturbine profiles, the TURBSIM software (At the National Renewable Energy... 

Unmanned Aerial Vehicles (UAVs) have attracted huge attention in recent years due to the technology improvements. Among them, Unmanned Helicopters (UHs) have great importance because of their special abilities. In this research, the problem of design and implementation of an actual flight control system for an unmanned helicopter is investigated. For this purpose, first a multi-level flight simulation environment is developed in Simulink software environment to model the helicopter flight dynamics. The system identification, control system design and implementation are successfully performed in this flight simulator. Next, the actual helicopter flight control system is designed and produced... 

This paper presents a robust adaptive backstepping control design for TREX-600 helicopter with flapping dynamics and dynamic uncertainties in the presence of Dryden wind gust. A nonlinear dynamic model is used to design the controller to let the helicopter track pre-defined time-varying waypoints and heading angles. In order to use the recursive design, the helicopter’s dynamic model is divided into three subsystems, such as altitude subsystem, yaw subsystem and horizontal subsystem. Adaptive backstepping method combines backstepping control and adaptation laws to deal with parameters uncertainties are designed for each sybsytem considering the coupling effects. The global asymptotic... 

In this study, the distributed six degree-of-freedom (6-DOF) coordinated control of spacecraft formation flying in low earth orbit (LEO) has been investigated. For this purpose, an accurate coupled translational and attitude relative dynamics model of the spacecraft with respect to the reference orbit (virtual leader) is presented by considering the most effective perturbation acceleration forces on LEO satellites, i.e. the second zonal harmonic and the atmospheric drag. Subsequently, the 6-DOF coordinated control of spacecraft in formation is studied. During the mission, the spacecraft communicate with each other through a switching network topology in which the weights of its graph... 

Nowadays, nano-positioners play an important role in advanced technologies, such as atomic force microscopy, genetic manipulation, nano-metrology, nano-fabrication, semi-conductors and etc.In this paper, a dynamical model has been derived for a nano-positioner. This nanopositioner was designed and fabricated in Sharif university of technology. In this paper the mentioned mechanism has been considered as a planar mechanism. First, a finite element model has been developed in Comsol multi-physics software. This model was used as the reference model in the next steps. Afterward, a 10 degrees of freedom model was proposed to estimate the Comsol model. The mass, stiffness, as well as damping... 

The present research has dealt with the modeling and control of a robotic prosthetic foot for transfemoral amputees. In the beginning of this research, we have modeled the normal gait. In order to accomplish this modeling, we have chosen a 7-body segment skeletal model of the human body and derived the motion equations using Lagrangian equations. Then, we have developed a smooth contact model for the ground. After controlling normal gait, we have attempted to model and control the ankle and knee prosthesis. We assumed a rigid model for the ankle prosthesis and derived its dynamic equations. Then, we developed a robust model reference adaptive impedance control (RMRAIC) scheme based on the... 

No one bears thinking about undergoing a surgery by an unexpirienced surgeon, the consideration of which implies the prominence of effective surgical trainings. The advent of utilizing haptic interfaces as a novelty in this field has led to a more promising surgery education. These haptic interfaces consist of three communicating parts namely: operator’s hand, haptic robot, and tissue virtual environment. Design and implementation of a proper controller in order to stabilize the haptic interface during surgery simulation, with acceptable transparency, is still novel an otherwise challenging research field. In this thesis we consider an appropriate nonlinear model for both virtual tissue as... 

Chemotherapy is a proven and effective systematic approach to treat various types of cancers. Despite its advantages, chemotherapy would kill healthy as well as cancer cells. To overcome this problem, different controlling strategies are implemented. This study aims to provide a medicine drug delivery schedule for chemotherapy (by designing a proper controlling system) based on the verifiable mathematical models. First, the dynamic model is analysed and stability points are reviewed. The selected model has five state variables and two inputs. In this study, the focus is on dynamic model analysis and obtaining an effective and appropriate treatment pattern by designing a proper controller. To... 

Nowadays, applications of industrial robots are significantly increasing due to their flexibility, programmable, accuracy, rapidity and etc. Among these, machining robots play an important role at manufacturing industries. One of the main concerns of the researchers, is the tip vibrations of robot arms. In most times, these vibrations are self-excited, unpredictable and intolerable. Thus, finding a method for reducing vibration should be investigated. The purpose of vibration control is vibration suppression to enhance the reliability of the system. The aim of this project is the modeling of the machining robot arm in turning process and then application of robust control to reduce... 

Air-handling unit (AHU) is one of the installations that is responsible to control the temperature and humidity inside a space using the heating, cooling, humidifier and drying air. At present, energy efficiency in building is an important issue to maintain the comfort conditions. One of the most common ways to optimize the performance of industrial installations is the use of control systems, which leads to the reduction in both of the costs and energy consumption. In this research, a multivariable nonlinear dynamic model of the AHU with one zone in the VAV (variable air volume) system for working in summer is considered. At first, introduction, limitations and driving the equations for the... 

Endoscopic sinus surgery is a minimally invasive surgery. Today, for the education of such surgeries, the surgical simulators are used. They could be used for both training of such a technique and pre operation planning. One of the features that could improve the efficiency of these systems and prepare the effective interaction with them is haptic.
In this thesis, an inexpensive sinus surgery simulator has been designed and implemented such that the operator could see sinus nasal in real time and could detect collisions between tool and virtual environment.
In this research, a 3D surface rendered model that extracted from 2D CT images has been used for construction of virtual... 

High speed and high accuracy are two of the major trends for many systems in the 21st century, such as machine tools and semiconductor equipment. For the purpose of high speed, it is well known that active magnetic bearing (AMB) is an inevitable substitute for conventional bearings. The noncontact nature of AMB brings up many advantages over the conventional bearing, including energy efficiency, low wearing, long life span, and absence of lubrication. Hence, AMBs are especially essential for high-speed rotating devices nowadays.
While the 3-pole AMB has been proposed for many years, it received little attention due to the magnetic coupling between poles that makes the 3-pole AMB system... 

Spacecrafts formation flying is defined as tracking or keeping of desired distance, relative position and attitude of two or more spacecrafts during a maneuver. Division of tasks between various smaller spacecraft’s and so reduction of need to advanced technologies, increase in reliability in system and doing special missions like 3-D imaging of planets and combining parameter measurements are some advantages of this method. For development of this method, in this thesisin addition of reviewing the common methods in spacecraft’s formation flying, we are supposed to provide a simple and new method called distributed control for controlling a formation of spacecrafts. Additionally by providing... 

Laparoscopic surgery is kind of minimally invasive surgeries that beside many benefits for patient, brings a lot of problems for surgeon such as fatigue and increasing probability of errors during surgery because of non-ergonomic long surgery time. Tele-surgical system is the way of technology to compete with these problems. In this systems surgeon could sit in an ergonomic consul, looking in the monitor, take master tools in his hand and do the surgery. Another robot would be placed on the patient and copy surgeons movements on the surgery tool. Major problem in today’s tele-surgical systems is lack of haptic feeling in a way that surgeon couldn`t feel any forces from slave`s environment... 

A sliding mode nonlinear controller has been developed to control a monohull hard-chine planing vessel. Planing vessels has been used for shoreward marine missions. On the other hand, according to vast shores of our country, offshore applications could be of extra importance for us. Autopilot of a vessel consists of two stages: trajectory design and trajectory control. In this project, trajectory control is being done using sliding-mode nonlinear control method, considering the fact that according to nonlinear dynamics of planing vessels, linear control would not show desirable results. In this dissertation, after description of main information about planing vessels and prior researches,... 

Laparoscopic surgery which is categorized under Minimal Invasive Surgery, has many advantages over conventional open surgery. Despite the beneficial effect of this method on patients, surgeons suffer difficulties in utilizing the method. Robotic surgery has been constituted as the answer to remove the difficulties yet retain the advantages.
In the so-called robotic surgery, the tool is handed to a robotic arm, i.e., the slave robot, which is installed and positioned at the bed side. The surgeon sits before a comfortable console and uses a joystick-like robot, i.e., the master robot, to manipulate the slave robot. The vision is also provided by a robotic camera holder and shown in a... 

The introduction of Minimally Invasive Surgery (MIS) has deeply influenced modern surgery. Despite all the advantages for the patient, this method produces some limitations for the surgeon. Limitations such as reducing degrees of freedom resulting in the loss of dexterity, depriving surgeons of the depth perception and sense of touch lead to human errors due to fatigue and intense mental activity. Overcoming these limitations is the reason for robots entering the operating rooms. In this research a robot-assisted surgery system including two 5-DOF robots is utilized. The goal of this research is to model and simulate this system and also to design a bilateral controller to provide haptic... 

In the recent decade many researches have been done on optimizing urban traffic. The invention of single-axel two-wheeled vehicle -which is also known as Segway- is toward this goal. This vehicle was invented in 2002 by Dean Kaman. The Segway doesn’t need fossil fuels, occupies very little space, is very convenient to use and its parallel wheel configuration makes it compact enough to be maneuvered through most spaces. After the invention of the Segway, two wheel balancing robots has attracted more attention and in recent researches Passenger-carrying capacity has been considered. In this project, by taking into account passenger-carrying capacity and possibility of wheel slippage, an exact...