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Modeling and Control of One-legged Somersaulting Robot
, M.Sc. Thesis Sharif University of Technology ; Alasty, Aria (Supervisor)
Abstract
Inspired by the agility of animal and human locomotion, the number of researchers studying and developing legged robots has been increasing at a rapid rate over the last few decades. In comparison to multi-legged robots, single-legged robots only have one type of locomotion gait, i.e., hopping, which represents a highly nonlinear dynamical behavior consisting of alternating flight and stance phases. Hopping motion should be dynamically stabilized and therefore, presents challenging control problems. A large fraction of studies on legged robots have focused on modeling and control of single-legged hopping machines. In this research, somersaulting is introduced as a kind of hopping motion for...
A robotic model of transfemoral amputee locomotion for design optimization of knee controllers
, Article International Journal of Advanced Robotic Systems ; Volume 10 , 2013 ; 17298806 (ISSN) ; Farahmand, F ; Osman, N. A. A ; Zohoor, H ; Sharif University of Technology
2013
Abstract
A two-dimensional, seven link, nine degrees of freedom biped model was developed to investigate the dynamic characteristics of normal and transfemoral amputee locomotion during the entire gait cycle. The equations of motion were derived using the Lagrange method and the stance foot-ground contact was simulated using a five-point penetration model. The joint driving torques were obtained using forward dynamic optimization of the normal human gait and applied to the intact joints of the amputee. Three types of motion controllers; frictional, elastic and hydraulic were considered for the prosthetic joints of the amputee and their design parameters were optimized to achieve the closest...
Dynamic modelling and control of a sphere-based micro robot with adjustable arm
, Article MARSS 2018 - International Conference on Manipulation, Automation and Robotics at Small Scales, 4 July 2018 through 8 July 2018 ; 2018 ; 9781538648414 (ISBN) ; Nejat Pishkenari, H ; Meghdari, A ; Sharif University of Technology
Abstract
In this article, we propose a three-dimensional model of a low-Reynolds-number swimmer that consists of three small spheres connected to a larger sphere via three perpendicular adjustable rods which enable the micro robot to swim along arbitrary trajectories. Then we focus on dynamic modelling of the swimmer and propose a control method to control the position of the micro swimmer in a low Reynolds number flow. The control aim intended in this article is that the middle sphere to follow a desired trajectory and respective simulation results from control indicates successful accomplishment in application. © 2018 IEEE
Design an Analysis of a Heartbeat Motion Compensation Controller in a Robotic Coronary Artery Bypass Graft Surgery
, M.Sc. Thesis Sharif University of Technology ; Behzadipour, Saeed (Supervisor)
Abstract
The Coronary artery bypass grafting surgery is one of the most complicated and invasive surgeries, in which the chest is cleaved up to 20 cm. Also, heart motion with 1-2Hz frequency bothers surgeons to perform on. This leads surgeons to get interested in minimally invasive robotic surgery methods. The idea is to synchronize the robot motion with heart, in order for surgeons to perceive it stationary. This needs 3 major stages: online taking of data, estimate the future heart motion, and control the robot. First studies employ visual seroving for control demand. Later studies, although differ in data collection methods, rely on classic error-based feedback controllers, such as PID. Fast...
Neural control of an underactuated biped robot
, Article 2006 6th IEEE-RAS International Conference on Humanoid Robots, HUMANOIDS, Genoa, 4 December 2006 through 6 December 2006 ; 2006 , Pages 593-598 ; 142440200X (ISBN); 9781424402007 (ISBN) ; Hamed, K. A ; Sharif University of Technology
2006
Abstract
According to the fact that humans and animals show marvelous capacities in walking on irregular terrain, there is a strong need for adaptive algorithms in walking of biped robots to behave like them. Since the stance leg can easily rise from the ground, the problem of controlling the biped robots is difficult. In other words, the biped walkers have fewer actuators than the degrees of freedom. So they are underactuated mechanical systems. In this paper according to the humans and animals locomotion algorithms, the stability of an underactuated biped walker having point feet is investigated by central pattern generators. For tuning the parameters of the CPG, an effective energy based...