Sharif Digital Repository

Using learning from demonstration approaches is one of the ways to teach a robot how to perform different skills. In classic methods of learning from demonstration, the subject should wear some sensors and devices which is and expensive way. But, with the progresses that have been made in the context of computer vision, it is possible now to achieve to the same results with less cost. Learning from observation is the approach that would be used in this project to do that. By using this method, when robot watches a video, it tries to understand the behavior of the subject and behave in the same way.The purpose of the project is that the robot learns some social (interactive) skills through... 

Being harmless to living tissues makes magnetic robots very promising for medical applications. Furthermore, since these robots are driven by external magnetic fields, no actuators are needed to be placed on the robots, enabling them to come in very small dimensions if necessary. Motion control of small magnetic particles paves the way for future applications, such as deliberate drug-delivery, sampling, and lowinvasive surgeries.The goal of this research is to design and construct a platform for generating desired magnetic fields in order to control the motion of magnetic robots in threedimensional space. In order to do so, a system of eight electromagnetic coils with iron cores was built.... 

Motion simulators have been highly sought after by the growth of the aerospace industry. In the meantime, the Stewart mechanism, or the so-called Hexapads, is a robot that, in addition to being used in machining tools, is mainly used to simulate the flight. The robot is considering the project to test parts and equipment installed in marine vessels under sea movements and waves. Therefore, according to information obtained through real case studies, the purpose of this project is to design and implement a hexapad controller and user interface for samples weighing up to 2 tons which can handle linear accelerations up to 1 g, rotary accelerations up to 200 º / s2 performs at a frequency... 

Nowadays, multi-agent robotic systems are implemented to perform various operations such as military mission, search and rescue operations, etc. One of the most interested robotic platforms for multi-agent systems is quadrotor aerial robot. In this paper, a team of quadrotors is prepared to perform a formation flight toward a specified target in order to catch and transport it on a desired path. Therefore, at first, trajectory tracking control of the quadrotor has been studied and two types of controllers have been introduced: Hierarchical controller and Non-hierarchical controller. Coordinate free structure of the hierarchical controller provides distinctive properties and guarantees... 

In this project, the final goal is to create a team consisting of a UGV and a quadrotor capable of relative tracking and coordinated landing, with focus on quadrotor control. What we mean by cooperative control in this project is control of quadrotor for the purpose of cooperation with a UGV; This should not be mistaken with another sense of cooperative control in which the control algorithms are developed for both of the robots or are based on the interactive dynamics of the robots.In order to accomplish this goal, an experimental testbed consisting of a quadrotor and a UGV capable of communication and data exchange was developed as a first step. The quadrotor was constructed using... 

Most elderly and physically disabled people suffer from lack of functionality and dexterity in their elbow or wrist. These disabilities are due to the damages mostly caused by sport surgery, spinal surgery, or stroke. Therefore, design of an assistive exoskeleton robot for upper limb movements seems necessary. The purpose of this study is to design, fabricate and deliver a control algorithm for an assistive wearable robot. The robot has two degrees of freedom in order to help the flexion/extension of elbow and wrist. Furthermore, various kinds of control systems incorporated in rehabilitation robots are investigated and their advantages and drawbacks are compared. Then, some conventional... 

One of the most significant aerial vehicles which has been subject of study of so many engineers and students is quadrotor or quadcopter, which is a cross sectional configuration of motors and propellers. This aerial robot is controlled through slight differences between the angular velocities of the four motors, and robot dynamics is completely nonlinear, thus sophisticated control algorithms are needed. The aim of this project consists of design, fabrication and control of a quadrotor capable of stable hovering. First, some preliminary decisions about general charachteristics of the robot were made. According to these decisions, other mechanical parts were designed and fabricated. Then,... 

The goal of controlling robot manipulators is to perform the mission intended for its end effector. Model-based control is a solution that can achieve the control goal with high speed and accuracy in the presence or absence of environmental obstacles by using the knowledge of the robot model. In this thesis, the Armtin 5 robot model parameters were identified in two steps. In the first step, the gravity and friction parameters and in the second step, the dynamic parameters were estimated. In the estimation of gravity and friction parameters, the non-linear behavior of friction causes the estimated parameters to be accompanied by a large amount of error. Estimation of the parameters was... 

In today's world, mobile robots have many applications in defense, transportation and industry. A robot may not be able to handle a mission alone or there may be different roles to perform a mission that a robot alone cannot perform, so the need to work with team robots is felt to the Necessary that by development Robot Technology and Advances in Communication, Microelectronics, Computing Technology, and Multi - Factor Expansion, robotic systems are widely used in theoretical research due to their flexibility, robustness, and scalability. In this research, robots are controlled in a coordinated manner as a team. In this research, algorithms were developed so that in a two and... 

In this work, we try to develop a method for searching for an object which is known to us and also returning it back where the search was begun, through shortest possible path. The surrounding environment was assumed unknown and only a stereo camera and an IMU exist to work with. The proposed method was developed in Linux using GPU and with C++ language and also achieved 58 fps. Parallel programming was utilized in different parts of the algorithm and obstacle avoidance is guarranteed. The surrounding environment and obstacles are assumed changing over the time  

With technological advances in fabrication and control of prosthesis and assistive devices the importance of such systems has increased drastically. On the other hand the appropriate coupling of these devices, especially the exoskeletal systems with the upper or lower extremities is of immense importance as it is an integral part of the control system. In particular, the control strategy and its ability to adapt the exoskeletal system with the existing and physiological functionality of the user, is an integral part of the system requirement. In the controller implementation, a number of methods are proposed including using the excitation signal, similar to the existing neuromuscular system.... 

This thesis is devoted to deriving a port Hamiltonian control approach for different scenarios of brachiation movement by a two-link underactuated planar robot called brachiation robot. The port Hamiltonian modeling and control of this type of robot is introduced for the first time and shows promising results in the analysis and simulation as will be showed here. Animals have long inspired roboticists. Their dexterity, versatility, flexibility of motion and great variety of behaviors has made them benchmarks for robot performance. Recently things have begun to change and robots are now capable, to a limited degree, of mimicking the behavior of animals. This paper studies a type of...