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Positioning, Tracking and Shape Control in Micro-beams Via Piezoelectric Actuators
, M.Sc. Thesis Sharif University of Technology ; Alasti, Aria (Supervisor) ; Salarieh, Hassan (Supervisor)
Abstract
Nowadays, micro systems are one of the most important scientific and industrial tools and become very important. Most of these systems are working based on deflection of a micro beam. As a result, studing performance of micro beams and controlling them have significant importance for science and engineering.Amoung micro beams cantilever and clamp-clamp beams, which are actuated by electrostatic or piezoelectric actuators, are very applicable. For example, micro cantilevers are used in Atomic Force Microscopy, Microswitches, acceleromiteres, and micro clamp-clamp beams are employed in micro mirrors and Grating Light Valves.In this research, a micro cantilever actuated with a piezoelectric...
Mechanism synthesis for path generation using the curvature based - Deflection based objective function
, Article WSEAS Transactions on Systems ; Volume 5, Issue 12 , 2006 , Pages 2839-2843 ; 11092777 (ISSN) ; Jafarijashemi, G ; Mamduhi, M ; Aghmioni, A. N ; Zohoor, H ; Sharif University of Technology
2006
Abstract
This paper proposed a new curvature based path-description method for path-generation of planar mechanism, in which the position vector of a point on coupler, which follows most closely a predefined path, is directly calculated as a function of coupler motion properties. In addition this curvature based method makes it possible to define an objective function independent of rotation and translation transformations. Therefore, in this method, initial position, orientation, and coupler point vector parameters are not the optimization variable. These five parameters could be calculated as a function of other design parameters and they are found when these optimal values are obtained. Reducing...
Simplified modeling and generalized predictive position control of an ultrasonic motor
, Article ISA Transactions ; Volume 44, Issue 2 , 2005 , Pages 273-282 ; 00190578 (ISSN) ; Haeri, M ; Sharif University of Technology
ISA - Instrumentation, Systems, and Automation Society
2005
Abstract
Ultrasonic motors (USM's) possess heavy nonlinear and load dependent characteristics such as dead-zone and saturation reverse effects, which vary with driving conditions. In this paper, behavior of an ultrasonic motor is modeled using Hammerstein model structure and experimental measurements. Also, model predictive controllers are designed to obtain precise USM position control. Simulation results indicate improved performance of the motor for both set point tracking and disturbance rejection. © 2005 ISA - The Instrumentation, Systems, and Automation Society
Fuzzy control of robot manipulator with a flexible tool
, Article Journal of Robotic Systems ; Volume 22, Issue 7 , 2005 , Pages 367-382 ; 07412223 (ISSN) ; Sepehri, A ; Sharif University of Technology
2005
Abstract
In some tasks, a rigid robot manipulator handles a long, slender, and flexible tool, which usually has not been equipped with vibration measuring devices. This situation makes a different tool tip position control problem. In this paper, a new method will be presented for simultaneous tip position and vibration suppression control of a flexible tool on a rigid-link 3-DOF robot. This approach uses fuzzy logic rule-based controllers without using any sensors and actuators on the tool or a priori knowledge about the tool. Numerical simulation of robot and tool set has been accomplished and results support the fact that designed fuzzy controllers perform remarkably well in reducing vibrations...
Hybrid stepper motor backstepping control in micro-step operation
, Article 2005 ASME International Mechanical Engineering Congress and Exposition, IMECE 2005, Orlando, 5 November 2005 through 11 November 2005 ; Volume 118 B, Issue 2 , 2005 , Pages 993-997 ; Alasty, A ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2005
Abstract
A nonlinear position controller based on backstepping control technique is proposed for a hybrid stepper motor in micro-step operation. Backstepping control approach is adapted to derive the control scheme, which is robust to parameter uncertainties and external load disturbance. Simulation results clearly show that the proposed controller can track the position reference signal successfully under parameter uncertainties and load torque disturbance rejection. Copyright © 2005 by ASME
Position control of an ultrasonic motor using generalized predictive control
, Article 8th International Conference on Control, Automation, Robotics and Vision (ICARCV), Kunming, 6 December 2004 through 9 December 2004 ; Volume 3 , 2004 , Pages 1957-1962 ; 0780386531 (ISBN) ; Haeri, M ; Sharif University of Technology
2004
Abstract
Ultrasonic motors (USM) possess heavy nonlinear, and load dependent characteristics such as dead-zone and saturation reverse effects, which vary with driving conditions. These properties have made the position/velocity control of USM a difficult and challenging task. In this paper, a generalized model predictive (GPC) controller for precise USM position control is suggested. Simulation results indicate improved performance of the motor for both set point tracking and disturbance rejection. Since the motor and the controller both are of type one, the applied saturation would cause in wind up phenomenon. This drawback is removed by implementing the Quadratic GPC controller. © 2004 IEEE
Adaptive Attitude and Position Control of a Rigid Body Insect-Like Flapping Wing
, M.Sc. Thesis Sharif University of Technology ; Banazadeh, Afshin (Supervisor)
Abstract
In this study, adaptive control of attitude and position of a rigid body insect-like flapping wing is investigated. For this purpose, a non-linear dynamic and time varying modeling and simulation is carried out initially with six degrees of freedom, and then the accuracy of the simulation is evaluated during different test cases. In order to design the controller, non-linear and time varying dynamic is transformed into non-linear and time-invariant dynamic using theory of averaging. Then, a non-linear controller is designed based on Lyapunov stability theory. Due to the inefficiency of the aforementioned controller under disturbances and unknown uncertainties in the model, an adaptive...
Positioning, Tracking and Shape Control in Micro-Beams Via Electrostatic Actuators and Incomplete State Feedback
, M.Sc. Thesis Sharif University of Technology ; Salarieh, Hassan (Supervisor)
Abstract
Systems that are electrostatically actuated have found a vast role in MEMS application. This technology is used in optical systems, sensors, micro switches, and deformable mirrors. Raising the use of these systems in fields that needs better performance highlighted the need to accurate study of dynamics and control of electrostatic actuated systems in micro scale. This work is dedicated to design of an estimation and control system for a micro-beam that is actuated by electrostatic. After a comprehensive survey on pervious works that are done on dynamic, applications, fabrication and control of these systems dynamic of the system is fully derived. The environmental factors like fringing...
Design and Developing the Production Know-How of Large Servo-Hydraulic Valves
, M.Sc. Thesis Sharif University of Technology ; Durali, Mohammad (Supervisor)
Abstract
The focus of this project was on gaining the knowledge of design characteristics and manufacturing of a hydraulic servo valve. Hence, in the first stage, the model of the valve was considered. After investigating the important parameters which influence the performance of the valve, the effect of each parameter on the valve's efficiency was examined. One of the most important characteristics of the valve is the amount of lapping between the spool and sleeve. Numerical analysis was done and all the characteristic curves were elicited. Equations governing the dynamics of the plant including a servo valve, servo actuator and dynamic model of the turbine and waterway were presented. Then the...
Modeling and position control of a magnetic levitation system calculating eddy current based damping force
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) ; Volume 4A , 2014 ; Khodabakhsh, M ; Vossoughi, G. R ; Sharif University of Technology
Abstract
In this paper a magnetic levitation system is modeled and an eddy current based damping force is identified and used for position control of the levitated object in the system. In the magnetic levitation technology, contactless manipulation of a levitated object is done by use of magnetic fields. Also, the eddy-current based force is used to damp the motion of the levitated object. Eddy-current is generated in a plate which is placed underneath the levitated object due to the change of current in an electromagnet and the motion of the levitated object. First, using finite element method (FEM), the magnetic levitation system is modeled and the eddy-current based force acting on the levitated...
Two dimensional dynamic manipulation of a disc using two manipulators
, Article 2006 IEEE International Conference on Mechatronics and Automation, ICMA 2006, Luoyang, 25 June 2006 through 28 June 2006 ; Volume 2006 , 2006 , Pages 1191-1196 ; 1424404665 (ISBN); 9781424404667 (ISBN) ; Nili Ahmadabadi, M ; Meghdari, A ; Sharif University of Technology
2006
Abstract
In this paper, we analyze a Dynamic Object Manipulation (DOM) problem; throwing upward and catching a disc using two planar manipulators. The manipulators control the disc xy position dynamically and use its angular movement as a free parameter. We use a simple model for the system. Each manipulator has three links and three active joints. In addition, the disc has considerable radius and mass. Therefore, we design a simple mechanism in the palm to damp a portion of the impact. © 2006 IEEE
Stability analysis and nonlinear control of a miniature shape memory alloy actuator for precise applications
, Article Mechatronics ; Volume 15, Issue 4 , 2005 , Pages 471-486 ; 09574158 (ISSN) ; Alasty, A ; Salaarieh, H ; Sharif University of Technology
2005
Abstract
This paper presents a new approach for controlling SMA actuators with hysteresis compensation by using two energy based semi active controllers. SMA actuators exhibit severe hysteresis that is often responsible for position inaccuracy in a regulation or tracking system. In this paper, a SMA actuator model is recalled from [Alasty A, Shameli E. Dynamic modeling of a new varying stress SMA actuator for precise applications. In: Proceedings of 2004 IEEE international conference on mechatronics (ICM'04). Istanbul, Turkey, June 3-5, 2004]. Then, a PID and a novel PID-P3 controllers have been suggested to perform a position control. To investigate the stability of controlled system the...
Precise position control of shape memory alloy actuator using inverse hysteresis model and model reference adaptive control system
, Article Mechatronics ; Volume 23, Issue 8 , December , 2013 , Pages 1150-1162 ; 09574158 (ISSN) ; Sayyaadi, H ; Sharif University of Technology
2013
Abstract
Position control of Shape Memory Alloy (SMA) actuators has been a challenging topic during the last years due to their nonlinearities in the governing physical equations as well as their hysteresis behaviors. Using the inverse of phenomenological hysteresis model in order to compensate the input-output hysteresis behavior of these actuators shows the effectiveness of this approach. In this paper, in order to control the tip deflection of a large deformation flexible beam actuated by an SMA actuator wire, a feedforward-feedback controller is proposed. The feedforward part of the proposed control system, maps the beam deflection into SMA temperature, is based on the inverse of the generalized...
Positioning and tracking control of an amphibious single wheel robot
, Article 2008 ASME International Mechanical Engineering Congress and Exposition, IMECE 2008, Boston, MA, 31 October 2008 through 6 November 2008 ; Volume 11 , 2009 , Pages 545-551 ; 9780791848722 (ISBN) ; Alizadeh, D ; Sharif University of Technology
2009
Abstract
Amphibious single wheel robot consists of a sharp-edged wheel actuated by a spinning flywheel for steering and a drive motor for propulsion. The spinning flywheel acts as a gyroscope to stabilize the robot and also can be tilted to achieve steering. In this paper, the kinematics of a single wheel robot in water, Gyrover, is analyzed and then a simple mechanism for driving it is proposed. In previous studies, Lagrange approach is used for hydrodynamic modeling of the robot. A nonlinear position controller is designed to bring the robot to any desired position. Based on the designed controller, a tracking controller is augmented to the robot. For simplicity the added mass effect has been...
Modeling and Controller Design of a Single Bladed Aerial Vehicle
, M.Sc. Thesis Sharif University of Technology ; Banazadeh, Afshin (Supervisor) ; Saghafi, Fariborz (Supervisor)
Abstract
In this thesis, multi-body modeling of a monocopter air vehicle is developed based on the Newton-Euler approach along with nonlinear simulation in vertical flight phases consist of climb, hover and descent. Aerodynamic and thrust forces and moments are modeled utilizing blade element momentum theory. The sole control surface is modeled like a conventional flap on a wing. Free flight simulation is implemented in MATLAB Simulink environment to appraise the behavior of the monocopter dynamic and to show the efficiency and productivity of the suggested model. Simulation results present harmonic oscillations in Euler angles, linear and angular velocities that are compatible with the physics and...
Design and Fabrication of a Control Setup for a Miniature Mobile Robot Excited by Magnetic Field
, M.Sc. Thesis Sharif University of Technology ; Zohoor, Hassan (Supervisor) ; Nejat Pishkenari, Hossein (Co-Supervisor)
Abstract
Humans can take lots of advantages from influencing on small particles. Since manipulation of micro sizes by humans or macro robots, due to their precession and size, is not possible, a new field of study, called Microrobotics, has been introduced. To better understand the working principles in small dimensions, we first need to know the governing physics laws. This step helps us to identify the dominant forces in the small dimensions, which, in turn, leads to better actuation of miniature robots. Because of the size of the miniature robots, one of the best actuation methods is the interaction of the magnetic field on magnetic dipoles. To use the magnetic field as an actuation force, the...
Design, Fabrication and Control of a Tilting-Rotor Quadrotor
, M.Sc. Thesis Sharif University of Technology ; Nejat, Hossein (Supervisor) ; Behzadipour, Saeed (Supervisor)
Abstract
This project deals with the design, fabrication and control of a tilting-rotor quadrotor. This type of UAV can have high maneuverability in all 6 degrees of freedom (3D attitude and 3D position). The rotor axes can be tilted independently to produce desired force and torque vectors. This capability resolves limitations of the classic quadrotors and provides independent control of orientation and position. To control this UAV, we have proposed a control scheme relating the desired trajectory to the required forces and torques. Then a PID controller for the simultaneous control of position and attitude is designed. This controller is tested in a simulation and the results show that the control...
Control of a Link on Elastic Torsional Support and Experimental Verification
, M.Sc. Thesis Sharif University of Technology ; Mohammad Navazi, Hossein (Supervisor)
Abstract
A simple control system contains at least an actuator, a controlled link, and a foundation. These structures are not ideally rigid, this flexibility can appear willingly or unwillingly in any parts of the system or the connections between them. As a consequence of this flexibility, the movement of the controlled part will fluctuate unintentionally. In this thesis, a control system with rigid controller and flexible torsional base is investigated and controllers are designed and compared to reduce these unwanted vibrations. Finally, by implementing the controllers on the constructed system, the experimental results are obtained and compared with the analytical results.To fabricate the...
Fault-tolerant Control of Formation Flying Satellites Using Machine Learning
, M.Sc. Thesis Sharif University of Technology ; Assadian, Nima (Supervisor)
Abstract
In this thesis, a fault-tolerant method for controlling the relative position and attitude between two satellites in a leader and follower formation is proposed. The follower satellite is equipped with twelve thrusters which are installed on the satellite in a particular pattern. These thrusters are assumed to be afflicted by faults. The satellites are subject to external disturbances – such as the ellipsoidal gravity of Earth (J2), drag force, solar radiation pressure, and the third body, and a controller is designed to attain the desired formation under these disturbances.For this purpose, six separated neural networks are trained, one for each of the position or attitude channels. Since...
Stability Analysis and Control of Periodic Nonlinear Micro Air Vehicles
, M.Sc. Thesis Sharif University of Technology ; Banazadeh, Afshin (Supervisor)
Abstract
This research aims to identify dynamic behavior, determine stability properties, and choose an appropriate control method for nonlinear time-periodic (NLTP) systems by using the optimal design approach. The primary objective is to address the challenges associated with these systems, particularly in making them smarter and more autonomous, while acquiring the knowledge needed to overcome these challenges. In this respect, multi-body modeling and nonlinear simulation of a mono-wing, as a modern NLTP micro air vehicle, are initially developed. A trade study is performed in free-flight conditions based on sensitivity analysis of parameters such as initial conditions, geometry, and mass...