Search for: fuzzy-control
Total 141 records
Observer-based adaptive fuzzy controller for nonlinear systems with unknown control directions and input saturation, Article Fuzzy Sets and Systems ; Volume 314 , 2017 , Pages 24-45 ; 01650114 (ISSN) ; Shahrokhi, M ; Khajeh Talkhoncheh, M ; Sharif University of Technology
Elsevier B.V 2017
This paper addresses design of an observer-based adaptive fuzzy controller for a class of single-input–single-output (SISO) nonlinear systems with unknown dynamics subject to input nonlinearity and unknown direction. The proposed controller is singularity free. A high-gain observer is designed to estimate the unmeasured states, and the Lipschitz condition for proving boundedness of the estimated states is relaxed. The Nussbaum function is used to handle the unknown virtual control directions and the backstepping technique has been applied for controller design. It is proved that all closed loop signals are semi-globally uniformly ultimately bounded (SGUUB) and the output tracking error...
Article 2009 IEEE Aerospace Conference, Big Sky, MT, 7 March 2009 through 14 March 2009 ; 2009 ; 1095323X (ISSN); 9781424426225 (ISBN) ; Pouya, S ; Khansari Zadeh, M ; Sharif University of Technology
In this paper a fuzzy controller is developed for automatic landing of fixed wing Unmanned Aerial Vehicles (UAVs). It is assumed that the vehicle has a built in vision system which provides the runway relative position and orientation to be used in the designed tracking system. The stability of the controller was analyzed through vector field diagrams, and the system performance is tested through a complete 6DOF computer simulation. The results show a satisfactory performance of the controller all through the automatic landing phase. ©2009 IEEE
Development and control of an intelligent assistive exo-glove via fuzzy controller and emotional learning system, Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; 2020 ; Salarieh, H ; Boroushaki, M ; Sharif University of Technology
SAGE Publications Ltd 2020
The aim of this article is design, fabricate, and control a conceptual prototype of a flexible wearable robot to increase fingers’ force using a novel cable mechanism. In this robot, force and position are controlled in separate phases by a fuzzy system equipped with emotional learning. A Flexible structure has been chosen for this robot, because flexible gloves are lighter and much more suitable for use in daily tasks compared to rigid structures. Since this system is supposed to be substituted for weak or damaged limb, it should have a behavior similar to the body organs as much as possible. Therefore, a novel mechanism, inspired by the natural movement mechanism of the human hand, has...
M.Sc. Thesis Sharif University of Technology ; Bagheri Shouraki, Saeid
There are lots of researches performed to investigate human being learning and try to model it. But, in case of huge complexity of its structure and function, almost none of so-far learning algorithms can model human learning process and, indeed, performance of human brain in real problems is much more than these algorithms. Moreover, in many cases, human is not aware or informed about internal structure or mathematical model of the present system he is working on; a child learning to walk has no information about his neuromuscular system and his brain slowly learns how to convey his little body by choosing the proper timing of muscle contractions. One of the accomplished researches in order...
M.Sc. Thesis Sharif University of Technology ; Bagheri Shouraki, Saeed
The Active Learning Method is in fact an adaptive recursive algorithm which embodies a Multi Input and a Single Output (MISO) system as in a fuzzy combination of several Single Input systems and Single Output systems (SISO), and by utilizing a fuzzy technique of Ink Drop Spread tries to explore and extract input to output transfer function behavior in the system of a single-input to a single-output. Although in simulation state, the speed of this model is set at a much higher speed in comparison to other presented models, still is slower than the processing speed of human brain. In regards to hardware implementation, also there remain the fundamental implementation challenges through more...
M.Sc. Thesis Sharif University of Technology ; Selk Ghafari, Ali ; Zabihollah, Abolghasem
The aerial vehicle capable of vertical takeoff and landing (VTOL), have created an interest in the community of researchers and admirers of Unmanned Aerial Vehicles. Among the existing UAV's, those with the capability of vertical takeoff and landing are prominent due to their higher maneuverability and hover capability. Quadrotors mostly have been considered as a flying robot for save and rescue operations in dangerous and unreachable places in addition to its military application. In cross shape of Quadrotor platform on each edge is appointed an electric motor with light rotors that usually are controled by considering motor rates as their only inputs. This thesis aims, to simulate and...
Article Proceedings of the IEEE International Conference on Control Applications, 8 July 2009 through 10 July 2009 ; 2009 , Pages 456-460 ; 9781424446025 (ISBN) ; Pourtakdoust, S. H ; Heydari, H ; Sharif University of Technology
A fuzzy controller has been suggested for attitude control of magnetic actuated satellites in order to calculate the desired mechanical torque based on the attitude error including error in the angles and their rates. The problem of selecting proper magnetic dipole based on the known desired mechanical torque has been investigated, two different methods for the purpose has been suggested and the performance of the attained fuzzy magnetic attitude controllers has been shown under two different simulated conditions. © 2009 IEEE
Article IEEE International Conference on Mechatronics and Automation, ICMA 2005, Niagara Falls, ON, 29 July 2005 through 1 August 2005 ; 2005 , Pages 1357-1362 ; 0780390458 (ISBN); 9780780390454 (ISBN) ; Vossoughi, G. R ; Sharif University of Technology
This paper presents an approach to improve the sliding mode controller performance. Accordingly, a fuzzy controller is designed based on a limited number of rules and independent of the sliding mode controller complexity. To enhance the performance, this controller will continuously optimize the sliding mode controller parameters including hitting control gain, boundary layer thickness, sliding surface slope and intercept. The controller is applied to a two-degree-of-freedom robot and the experimental results are compared with a QFT based and a PID controller. The results demonstrate the significant performance improvement of the proposed controller. © 2005 IEEE
Article Journal of Robotic Systems ; Volume 22, Issue 7 , 2005 , Pages 367-382 ; 07412223 (ISSN) ; Sepehri, A ; Sharif University of Technology
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...
Design of car active suspension systems to obtain desired performance on reducing effect of road excitation on human health, Article DETC2005: ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Long Beach, CA, 24 September 2005 through 28 September 2005 ; Volume 6 A , 2005 , Pages 383-390 ; 0791847438 (ISBN); 9780791847435 (ISBN) ; Ahmadian, M. T ; Sharifi Sedeh, R ; Sadati, N ; Sharif University of Technology
American Society of Mechanical Engineers 2005
Advent of passenger cars has caused people to use them for more efficiency in their performance and wasting less time. Problems, however, still exist in them. For instance, since people travel with cars, their human bodies undergo in fatigue, restlessness, and sometimes health problems. Human body reaction under external vibration depends on the amplitude, frequency, and acceleration of the applied external excitation. These limitations which are usually announced by the bureau of standards imply the necessity of control of amplitude, vibration, frequency, and acceleration received by human body due to cars passing humps and bumps. In this paper, a quarter car model with active suspension...
Adaptive critic-based neuro-fuzzy controller in multi-agents: Distributed behavioral control and path tracking, Article Neurocomputing ; Volume 88 , July , 2012 , Pages 24-35 ; 09252312 (ISSN) ; Etemadi, S ; Alasty, A ; Vossoughi, G ; Sharif University of Technology
In this paper, we follow two control tasks in a leader following frame with undirected network and local communications. As the first goal, distributed behavioral imitation, which is necessary to fit agents with complicated motion equations in kinematic frames, is discussed. Providing real agents with behavioral controller makes them capable to act as a kinematic particle. The second goal is to design an active leading strategy for the LA to move the group on a predefined path. Both problems can be mathematically modeled in an affine form, which is the reason behind using a unique adaptive controller to solve them. The controller is based on a neuro-fuzzy structure with critic-based leaning...
Nonlinear control of multiple equilibrium systems and unknown sinusoidal disturbance by using backstepping technique and neural-fuzzy controller, Article ASME 2007 International Mechanical Engineering Congress and Exposition, IMECE 2007, 11 November 2007 through 15 November 2007 ; Volume 9 , 2007 , Pages 415-422 ; 0791843033 (ISBN) ; Alizadeh, D ; Sharif University of Technology
American Society of Mechanical Engineers (ASME) 2007
Controlling nonlinear systems have always been a challenging problem. Complexity is mostly the result of nonlinear systems behavior dependence on initial conditions and input. Linearization techniques are such kinds of nonlinear systems analysis tools, which can give suitable results in neighborhood of equilibrium points. In addition, phase portraits are very efficient for visualizing the behavior of system in equilibrium points' neighborhood. In this paper, designing a controller for a low order dynamic system with multiple equilibrium points in presence of a sinusoidal disturbance with unknown amplitude and unknown bounded frequency is investigated. The proposed controller is based on a...
M.Sc. Thesis Sharif University of Technology ; Bagheri Shouraki, Saeed
Controlling four legged robots is a complex challenge. The previous works in this field can be divided into two main categories, Analytic method and intelligence method. The analytic method is based on extracting the motion equations of the robot, but in most cases these equations are so complicated, and their implementation is difficult. Another method is intelligence method, which is based on learning algorithms. Despite the improvements in walking robots field, still their walking quality is far from human and animal walking. Researchers believe that this advantage is the result of the learning ability in animals and human. Therefore in this paper the human learning ability is used to...
M.Sc. Thesis Sharif University of Technology ; Salarieh, Hassan ; Khayyat, Ali Akbar
The huge capability of high resolution satellite imageries (HRSI), that includes spatial, spectral, temporal and radiometric resolutions as well as stereoscopic vision introduces them as a powerful new source for the Photogrammetric,Remote Sensing and GIS communities. High resolution data increases the need for higher accuracy of data modeling.The satellite orbit, position, attitude angles and interior orientation parameters have to be adjusted in the geometrical model to achieve optimal accuracy with the use of a minimum number of Ground Control Points (GCPs). In order to obtain high resolution and definition imaging for many applications including surveillance, target tracking, and...
M.Sc. Thesis Sharif University of Technology ; Nobahari, Hadi
Spinning vehicles are a large category of aerospace vehicles including shoulder launched missiles, intelligent anti-armor projectiles, guided rockets and some of re-entry vehicles, anti tank missiles and satellites. This thesis presents the problems of guidance and control in a spinning vehicle with a single plane of On-Off control surface. The missile uses this single surface to control both yaw and pitch channels. The actuator used in this missile is a discrete On-Off type which makes the missile behavior nonlinear. Using describing function technique, a linear model of the spinning missile dynamics in the presence of an On-Off actuator is derived and a classic controller is designed...
M.Sc. Thesis Sharif University of Technology ; Sarbazi Azad, Hamid
In past decades, we have seen the rise of integration density in chips making it possible to design a whole system on a single chip. The previously designed interconnection architectures for multiprocessors systems cannot directly be applied in on-chip systems (especially when the number of processor elements increases) since they require a different type of a cost-performance trade-off. This is why the interconnection networks of systems-on-chip (SoC) are such a problem. Network-on-chip (NoC) was being proposed as a scalable and reusable communication platform for SoCs, which makes use of the network model to develop efficient on-chip communication infrastructures. The NoC has a layered and...
M.Sc. Thesis Sharif University of Technology ; Vossoughi, Gholamreza
Magnetic levitation is an appropriate solution for noncontact 3D manipulation. Workspace of the previously proposed maglev systems is confined to a relatively small cube, which severely limits the application of this technology. In addition, most of the previously given mechanisms require the design and application of a subsystem in order to unify their magnetic field. In this paper, a moving magnet is proposed which results in a horizontally extendable workspace; moreover, the field unifying section is not needed since one electromagnet only is used. Further, details of the mechanism and finite element based design procedure of the magnet are presented. Dynamic equations of the system...
M.Sc. Thesis Sharif University of Technology ; Sayyadi, Hassan
Dynamic positioning system is a controller system used to maintain the position and heading of a vessel with no use of anchors, jack ups but only using the propellers installed on the vessel. A vessel has six degrees of freedom, including three rotations and three transfer. In dynamic positioning systems, the vessel is controlled only on the horizontal plane such that its position and heading are controlled according to predetermined values. To achieve this, position and heading of the vessel is determined and the controller system computes the direction and required power of each propeller. Preliminary systems utilized PID controllers. As the control science has advanced, model based...
M.Sc. Thesis Sharif University of Technology ; Zohoor, Hassan ; Sohrabpour, Saeed
Gyrover is a kind of robot which can move with only one single wheel. In this robot, all the mechanical and electronics’ systems are placed in the wheel of robot. So the wheel of robot is the boundary which separates the inner equipment of gyrover with outside environment. In this robot, only one wheel is used for moving, so the amount of friction of movement in gyrover robot is less in comparison with two and more wheeled vehicles. Because of this gyrover can move to more domains. Gyrover robot can move both on land and water. Gyrover robot is not intrinsically stable which means that it cannot stand on ground. So for stability of gyrover another dynamic system should be used. The best...
M.Sc. Thesis Sharif University of Technology ; Khayyat, Amir Ali Akbar
The present study discusses the problem of enabling a PUMA 560 electrical robot manipulator to interact with the environment using impedance control concept. The impedance control strategy maintains a pre-specified desired second order dynamic relation between the end-effector position and force and enables a stable transmission between unconstrained and constrained motion. In this study Position-Based Impedance Control (PBIC) is used which is more suitable for industrial manipulators. PBIC requires a position controller with high accuracy. Therefore, a nonlinear PID controller is used in the position loop which is capable of both tracking and regulating of the input signals and shows better...