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control-systems
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Design, Modeling and Control of a Delta Robot in Fine Machining Application
, M.Sc. Thesis Sharif University of Technology ; Salarieh, Hassan (Supervisor) ; Selk Ghafari, Ali (Supervisor)
Abstract
In recent years, industrial robots have been greatly used as orienting devices in industry, especially in the automotive, shipbuilding and aerospace manufacturing industries. Industrial robots are gradually finding their niche in manufacturing, replacing less universal and more expensive CNC-machines. Application area of robots is constantly growing; they begin to be used for the assembly, pick-and-place operations, machining operations and etc. The use of robots for machining operations is growing because of their flexibility to perform a broad spectrum of tasks at a lower cost when compared with machine tools. Recently, parallel robots have attracted more and more researchers’ attention in...
Model Predictive Control for Determining Optimal Real-time Operation of Heating (Cooling) System with Minimum Energy Consumption
, M.Sc. Thesis Sharif University of Technology ; Rajabi-Ghahnavieh, Abbas (Supervisor) ; Boroushaki, Mehrdad (Co-Advisor)
Abstract
Considering the increasing importance of energy conservation in recent decades, different technologies regarding energy system have been developed to satisfy this goal. Building section is responsible for a big portion of final energy consumption and greenhouse gasses emission around the globe. Utilizing energy consumption reduction techniques in the building sector is among the foremost solutions to achieve the energy conservation potentials in this sector which would be followed by a decline in greenhouse emissions. Considering the contribution of heating and coling systems in a building’s energy use, optimizing these systems could have a huge effect on a building’s final energy...
Impact of Internally Heat-Integrated Distillation Column Configuration on Energy Saving
, M.Sc. Thesis Sharif University of Technology ; Pishvaie, Mahmoud Reza (Supervisor) ; Rashtchian, Davood (Supervisor)
Abstract
Distillation is the most widely-used but the most energy-consuming separation process in the chemical industry. The thermal energy added at the reboiler is used to evaporate a liquid mixture and is wasted when liquefying the vapor flow at the condenser to obtain a reflux liquid flow. However, the thermal energy recovered at the condenser cannot be used to heat other flows in the same distillation column since its temperature is lower than the other stages. To improve the low energy efficiency of distillation, various new ideas have been proposed in the literature. One of them is the internally heat-integrated distillation column (HIDiC). In a conventional distillation column, the temperature...
Satellite Attitude Actuator Fault Detection and Identification Using Adaptive Neuro-Fuzzy Inference System (ANFIS)
, M.Sc. Thesis Sharif University of Technology ; Asadian, Nima (Supervisor)
Abstract
This thesis focuses on the detection and estimation of faults occurring in one of the reaction wheel axes of a three-axis stabilized satellite. The wheel axes are aligned with the satellite's body axes, and the emphasis is on the attitude (rather than position) of the satellite. The primary goal of the subsystem is to determine and control the satellite's attitude, transitioning from its initial state to a desired Earth-pointing state. It is assumed that environmental disturbances, including gravitational disturbances and Drag related disturbances, are considered. Based on this, a PID controller is designed after modeling the nonlinear kinematics and dynamics of the satellite using Euler...
Development of Guidance and Control System of Environmental Pollution Aerial Inspection System Focusing on Industrial Chimneys
, M.Sc. Thesis Sharif University of Technology ; Banazadeh, Afshin (Supervisor)
Abstract
In this research, first the use of an aerial system for the inspection of industrial chimneys has been investigated. Then, a series of typical requirements are set for the mission of the flying vehicle, and then a suitable multi-rotor for inspection of industrial chimneys has been designed. After determining the aircraft, among the large number of controllers that have been implemented on the multi-rotors since 2008 , the ADRC controller is selected and based on it a control system for the aircraft has been designed. Finally, this controller is tested in 5 different scenarios to evaluate and show its performance and robustness
Design and Dynamic Analysis of a Coaxial Thrust Vectored Rotor VTOL Drone
, M.Sc. Thesis Sharif University of Technology ; Sagafi, Freeborz (Supervisor)
Abstract
There is a class of small vertical take-off and landing flying vehicles that only have a dual coaxial engine on top and move based on the thrust vector control method. In this project in order to have better insight about the physical mechanism we are dealing with, a conceptual design of a prototype vehicle is first carried out. It is then followed by extraction of two and three dimensional dynamic models of the vehicle. By computer simulation and a simple dynamic analysis, the equations are verified and the movement of the aircraft is discussed for different flight phases
Analysis and Optimization of Surge Control System of a Centrifugal Compressor
, M.Sc. Thesis Sharif University of Technology ; Mazaheri, Karim (Supervisor)
Abstract
The surge phenomenon, as the most important aerodynamic instability, has caused a severe drop in efficiency and performance in centrifugal compressors, and its prevention and control is considered one of the main concerns of industrialists. The purpose of this study is to design and develop a surge control system in order to improve the stability and safety of the system under the effect of surge. In this research, after simulating the existing control system and working line in Borzouyeh Petrochemical Industry, by designing and adding the piston surge active control system to the above centrifugal compressor and using the combined control system, the flow rate of the bypass path has been...
Hydrodynamic Circuit Modeling of Surge Control System of a Centrifugal Compressor with Variable Gas Combination to Combine an Active Surge Control System with Surge Avoidance System
, M.Sc. Thesis Sharif University of Technology ; Mazaheri, Karim (Supervisor)
Abstract
In this research, first, the performance map and surge line of 46M6 and 46MB8 multi-stage radial compressors, which have 6 and 8 stages, respectively, have been estimated and invarianted. Invarianting the performance map makes the performance curve and surge line of the compressor, unchanged from input conditions, including molecular weight, which is very important for control systems. Then, the hydrodynamic circuit of Compressor System C-3002 of Nouri Petrochemical Company was modeled according to the characteristics of its components by solving equations in MATLAB software. main working condition of the hydrodynamic circuit is close to Start of Life operating condition which has a...
Thermodynamic Analysis of a Combined Ejector-assisted System for Electric Equipment Cooling and Air Conditioning in Electric Vehicles
, M.Sc. Thesis Sharif University of Technology ; Morad, Mohammad Reza (Supervisor)
Abstract
Transportation is one of the essential parts of human life and at the same time one of the main sources of greenhouse gases emissions that are harmful to the environment. Therefore, the use of electric vehicles have become widespread in recent years due to limited capacity of natural resources and environmental issues. As a result, attention to climate control systems for electric vehicles and electric aircrafts is growing rapidly. According to multiple studies, the integrated air conditioning-heat pump system is a suitable option as the climate control system.In this research, an air conditioning-heat pump system has been proposed and studied, which works based on the vapor compression...
Modeling and Design Analysis of an Aircraft Longitudinal Reversible Flight Control System and its Enhancement to Irreversible One
, M.Sc. Thesis Sharif University of Technology ; Pourtakdoust, Hossien (Supervisor) ; Raeesi Charmkani, Kamran (Supervisor)
Abstract
Flight control system (FCS) design, analysis and modeling has an important role in aircraft design and development process. However, FCS analysis and studies are rarely focused at university levels and its know-how and technical issues are almost proprietary to various aircraft industries. One of the key goals of this thesis is to express, introduce and implement the processes that need to be followed for a sample longitudinal reversible FCS design (RFCS), where the modelling aspects are described for an existing aircraft. The latter is achieved using existing drawings, system and aerodynamic data of an existing aircraft utilizing commercial tools such as CATIA for initial design and ADAMS...
Reliability Analysis of a Thrust Vector Control (TVC) System
, M.Sc. Thesis Sharif University of Technology ; Pourtakdoost, Hossein (Supervisor)
Abstract
Reliability modeling, analysis and computation of a Thrust Vector Control System (TVC) is investigated. In this respect, first the TVC subsystems including the jet vanes (JVs), sensors and actuators,... are identified and their pertinent Reliability Block Diagram (RBD) is depicted. Subsequently static reliability of a jet vane is calculated considering both structural and thermal loadings via related verified limit state functions. In addition, a sensitivity analysis is performed that identifies the key JVs design parameters from a reliability point of view. Next, knowing the structural and thermal reliability of the JVs, static reliability of the total TVC system is computed via utility of...
Elastodynamic Behaviour Analysis of Interceptor Flight Vehicle in Space
, M.Sc. Thesis Sharif University of Technology ; Haddadpour, Hassan (Supervisor)
Abstract
In this thesis, the effect of elastodynamic behaviour of an interceptor on it’s trajectory in space and accuracy in desired positioning and situation is investigated. The governing equations of motion are derived and linearized by using the basic equations of motion in the body frame axes and the mode summation method for elastic deformations. In order to control the interceptor, the closed-loop control on the yaw and pitch angles, is considered. The governing equations of motion are solved to determine the time response to investigate the structural effects on the stability, position and situation of interceptor. Finally, the effect of elasticity and vibrations on the interceptor’s...
Flight Performance and Maneuverability Enhancement of a Twin Engine Fighter Aircraft Using Integrated Thrust-Vector and Aerodynamic controls
, M.Sc. Thesis Sharif University of Technology ; Saghafi, Fariborz (Supervisor)
Abstract
In this thesis, maneuverability enhancement of a given twin engine fighter aircraft with integrated thrust-vector and conventional aerodynamic control surfaces havebeen studied. For this purpose a nonlinear 6DOF simulation program base on a near exact mathematical model has been prepared for the aircraft, and then a thrust vectoring system for producing moments about three body axes, like that used in F/A-18, has been added to the simulation. The control method that is employed to control the aircraft in simulation environment is based on Nonlinear Dynamic Inversion (NDI). Finally the Velocity Vector Roll (VVR) maneuver has been considered as an example tostudymaneuverability enhacement. It...
Measuring the Extent of Usage of Different Levers of Control in Three Iranian Companies with Different Value Creation Logics
, M.Sc. Thesis Sharif University of Technology ; Mashayekhi, Alinaghi (Supervisor)
Abstract
The purpose of this research has been measuring how much studied companies use different levers of controls. Management control system has been described as the system which ensures the organization about implementing its strategy (Antony, 2004; Simons, 1995). In this research we chose Levers of Control framework (Simons, 1995) as the proper model to describe management control systems in organizations. Using related literatures, we developed a questionnaire to measure how much different organizations use each levers of control. The proposed questionnaire was distributed in three businesses with different Value Creation Logics (Stabell & Fjeldstad, 1998), to provide a ...
Automatically Structuring and Tagging Bug Reports in Version Control Systems
,
M.Sc. Thesis
Sharif University of Technology
;
Heydarnoori, Abbas
(Supervisor)
Abstract
GitHub issue reports provide developers with valuable information that is essential to the evolution of a software development project. Contributors can use these reports to perform software engineering tasks like submitting bugs and requesting features. In the initial versions of issue reports, there was no standard way of using them. As result, the quality of issue reports varied widely. To improve the quality of issue reports GitHub introduced issue report templates (IRTs). However, despite of effectiveness of this feature which was introduced in 2016, only nearly 5% of GitHub repositories (with more than 10 stars) utilize it. Although issue report templates have advantages, their...
Embedded System Vulnerability Analysis Approach Based on Firmware Modification Attacks in Industrial Control Systems
, M.Sc. Thesis Sharif University of Technology ; Jahangir, Amir Hossein (Supervisor)
Abstract
A wide range of field devices, including Intelligent Electronic Devices (IEDs) and Remote Terminal Units (RTUs), are used in Industrial Control Systems (ICSs). These devices are embedded systems that are responsible for protecting the power system devices against faults and damage by controlling circuit breakers. Disruptions in command and control can result in accidents and harm. Due to their physical accessibility and the possibility of backdoors, blackout attacks may be designed and implemented on these devices in a manner similar to what has occurred in many countries in recent year.Many vulnerabilities have been reported for Real-Time Operating System (RTOS), firmware, and software of...
Categorization of Software Repositories in Version Control Systems
, M.Sc. Thesis Sharif University of Technology ; Heydarnoori, Abbas (Supervisor)
Abstract
Developers often seek to find projects that match their topics of interest in version control systems with the goal of reusing code, extracting similar requirements, learning, and more. However, due to the widespread use of these systems, the number of projects maintained on them is huge and ever-increasing. This has made it difficult to identify projects based on their topics. GitHub, as a prominent version control system, with the aim of facilitating access to projects based on their topics, has provided the possibility of assigning software topics to projects in the form of free-text tags for users. Assigning a correct and complete set of topics to software projects allows programmers to...
Improving Remote Attestation Techniques for IoT Devices using Physical Model
, M.Sc. Thesis Sharif University of Technology ; Bayat Sarmadi, Siavash (Supervisor)
Abstract
Due to the widespread growth in the use of IoT devices, authors consider these devices as an attractive target platform. Several approaches have been proposed to defend IoT devices against various attacks. However, most of them suffer from some shortcomings such as being computationally expensive, not being general, or not being robust enough.Due to the attacks such as firmware modification and the existence of computational limitations, the use of local approaches is inefficient. Another approach is to use remote attestation techniques, which are divided into two categories, static and dynamic. However, static detection techniques are vulnerable to runtime attacks. Furthermore, existing...
Towards a Architectural Model for Configuration Management of Software Architecture
, M.Sc. Thesis Sharif University of Technology ; Habibi, Jafar (Supervisor)
Abstract
Given the importance of software architecture in the field of software engineering and its influence, much attention has been paid to it in the past few decades. This has led to significant progress in the development and expansion of the technical foundations of design as an engineered discipline and today is regarded as a mature branch of producing cycle and software development. But considerations related to design based on architecture and activities required to achieve a correct and complete architecture 100 percent is difficult and considering progress of technology, this problem is adding to the concerns in the field of architecture. As a result, different approaches and activities...
An Approach for Keeping Consistency of Models During the Evaluation of Modeling Languages
, M.Sc. Thesis Sharif University of Technology ; Habibi, Jafar (Supervisor)
Abstract
The development of a complex software needs an abstraction mechanism which is called Model Driven Engineering mechanism. In order to have a successful model based process, we need an appropriate tool such as version control systems to support our model-based process. On the other hand, developers need a mechanism to synchronize them with VCS systems. One of the concerns in modeling languages is the compatibility and the consistency of the models and modeling languages during their evaluation. the focus of the former researches was mostly on the consistency of the models during their evaluation, and to this end, lots of approaches have been proposed for keeping the consistency of the models...