Sharif Digital Repository

In this thesis, black-box identification, designing and implementing an iterative learning controller for the quadcopter was performed. Initially, the open-loop quadcopter system is unstable, so for black-box identification, a controller must first be implemented to stabilize it, but since no model is available from the system, the controlling parameters of the stabilizer through a proportional-integral and a proportional controller are executed as trial and error. To identify the roll and pitch models, the quadcopter is carried out using a radio controller and the measurements are saved during flight. Different models and methods are used to black-box identification, and finally the best... 

In this study, the method of recognizing image patterns by image processing to guide the quadcopter to the landing point is expressed. For this, first the forces and torques on the quadcopter in the body system are calculated and after transferring to the inertial coordinates, the quadcopter dynamics with the use of Newton-Euler law is simulated in the MATLAB software environment. Then, a simple PID controller is designed to control the attitude, height and position of the quadcopter and create stability in the quadcopter dynamics. Because quadcopter navigation is dependent on visual data, a simulation environment called VRML is used. This environment has the ability to create a... 

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... 

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... 

As the leading kind of multi-rotors, quadrotors have become one of the most popular Unmanned Areal Vehicles (UAVs). These robots are very agile, but their speed is limited when performing decent maneuvers. In this project, a special quadrotor with dihedral-rotating arms is presented in order to increase the decent velocity of the vehicle. The conceptual and detailed designs of the vehicle are presented first, followed by the construction of the quadrotor. The fabricated quadrotor measures 25 cm in size, has a weight of about 1 kg, and can support up to 70 degrees of dihedral angle. Afterwards, the dynamic equations of the dihedral quadrotor are driven and simulated. The effects of dihedral... 

Quadrotors have limitation in performing fast descent maneuvers due to Vortex Ring State (VRS) region which make quadrotor unstable. In order to avoid entering VRS, a velocity constraint considered which it should be satisfied during this maneuver to guarantee a safe and stable fast descending maneuver by quadrotor. The purpose of this thesis is to overcome limitation in speed space of quadrotor in order to reduce the time of fast descending maneuvers by using Reinforcement Learning Techniques. A new cascade controller proposed which using PID in inner loop as a low level controller and DDPG as one of reinforcement learning techniques in outer loop as high level controller in order to... 

In recent years with the development of industrial automation, artificial intelligence, and the coming of the fourth-generation industrial revolution, making robots intelligent and solving old challenges in non-linear systems in order to make human life easier has always been the point of view of researchers. Flight systems are always considered to be one of the most nonlinear systems. In linear systems, a PID controller can be easily designed and implemented; But in non-linear systems, because the set point is constantly changing, the PID gain must be manually adjusted by the operator, which is almost impossible in practice; Therefore, finding a fast and efficient way to solve this... 

Quadcopters are a bunch of vertical takeoff and landing UAVs and generally consist of four symmetric arms, each possessing a rotor-blade at the end. Quadcopters are able to retain their state and position by performing static maneuverability. Conventional quadcopters have less actuators (four engines) than their DOF (six degrees of freedom in the space). Thus, it is impossible to control all DOF of the system independently. Nevertheless, one can make a solution to this problem by increasing the number of actuators, so that each rotor-blade can also rotate about the corresponding arm. Such a quadcopter is so called a “tilt-rotor quadcopter”. The aim of this work is to model a tilt-rotor...