Sharif Digital Repository

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... 

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... 

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... 

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... 

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... 

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... 

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... 

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... 

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... 

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... 

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...