Sharif Digital Repository

Recent studies show that spherical shape robots have been widely developed by many robotic researchers. A spherical shape can be also benefited in keeping mechanical components and electronic circuits inside a compact volume. The shell can also perform rolling motions for going fast and smooth on flat area. The reconfigurable spherical robot can be configured into a form of two interconnected hemispheres with three legs equipped with three Omni-directional wheels. The conceptual design of the robot will be initially packed and deployed in a spherical configuration. The spherical construction offers ease in transportation and deployment; for example, a number of these robots can be packed and... 

The goal of fracture reduction in orthopedic surgery is to reposition the bone fragments in their anatomical orientation (alignment), and the fracture ends closed to each other (apposition). Reduction of long bone fractures is became an interesting subject in the field of robotic aided surgery in pervious decade. Nowadays reduction of femur is carried out by surgeons and medical staff in surgery. Due to the large holding forces necessary, exact positioning is difficult and time consuming. What is needed is an automated system whereby the fractured ends of the bone may be precisely positioned without the need for multiple docking attempts. The fragments need to be held in place as long as... 

Parkinson's disease is a destructive and long-term disease of the central nervous system. This disease especially affects the motor system. Parkinson's patients can be studied under dopaminergic and non-dopaminergic conditions. The non-dopaminergic state means not taking the drug, for at least 12 hours, and the dopaminergic state, from one hour to less than 12 hours after taking the usual dose of the dopaminergic drug. The aim of this study is to examine and compare the statistics and characteristics of Parkinson's patients in dopaminergic and non-dopaminergic states, focusing on reaching and tracking activities. It also aims to analyze the differences before and after rehabilitation in... 

In this research the flexibility of subterranean levels on foundation input motion (FIM), especially rocking component is investigated through parameter analyses. The so-called motion is induced as a result of kinematic soil-structure interaction (SSI). The foregoing interaction reduces the translational component of foundation input motion in rigid embedded foundations when compared to the free-field motion (FFM), as well as yielding rocking component in the foundation. On the other hand, increasing the embedment depth which is equivalent to the presence of subterranean levels in a building decreases the commonly-held “rigid” assumption’s accuracy for the embedded part. Given this effect,... 

Hyper-redundant manipulators have large number Degrees of Freedom. Because of their redundancy, such manipulators have the advantage of obstacle avoidance, overcoming singularities and intrusion into highly constrained environments. The most challenging task in designing hyper-redundant manipulators is the synthesis of actuating mechanisms with appropriate kinematics and effective power supply. Most of previous techniques in implementing hyper-redundant robots have the disadvantages of: -Using large number of actuators, -Heavy weight due to large number of actuators, -Complexity of the control system due to need of synchronizing subsets of motors. In this thesis a novel hyper redundant... 

In this study, we create an evolution function that assesses prosthetic hands in terms of their ability to grasp various objects like a human hand. It is required to evaluate the reachable workspace of prosthetic hands and grasp ability to assess it completely. The first one can be done by using forward kinematics. The Volume of the Grasp Wrench space, one of the grasp qualities indexes, is used to measure the second one. Randomization and grasp taxonomy are used to generalize the grasp quality to indicate the prosthetic hand functionality. Afterward, the created evaluation function is used to specify the importance of each finger and DOF. The results show that the most significant finger is... 

Exoskeleton is a newborn technology for disabled people. Personal exoskeleton is a type that is suitable for replacement of wheelchair. Exoped, the first Iranian exoskeleton made by Pedasys company, was a rehabilitation one. The purpose of this research was enhancing the design of its actuators to accomplish lighter, smaller and cheaper one. At first we identified the different loads that are applied to actuators of exoskeleton and we tried to decrease the number of actuators needed, as more as possible. Then we modeled the exoskeleton-user system to measure the required parameters. Using this model, we conducted an algorithm to design appropriate gait cycle for walking with the help of... 

Quantitative motion quality evaluation has been always of much significance for CVA patients, especially the HCP ones. The purpose of the present study is to introduce and analyze the efficiency of a novel index, namely “Consumed Energy Index”, for evaluating the quality of the motions performed by HCP patients. For this purpose, Firstly, a Musculo-Skeletal model of the human arm was provided on Matlab and OpenSim softwares, with four DoFs: three DoFs at shoulder and one DoF at elbow joint as well as eight muscles. The muscles are in pairs of flexor-extensor at each DoF. The model is capable of receiving Cartesian trajectories for joints and solving inverse kinematics and dynamics to obtain... 

In this study, an elastic-plastic analysis of fiber reinforced metal matrix composite structures loaded by uniaxial uniform tension in the direction perpendicular to the fiber is carried out by assuming elastic-plastic matrix with kinematic hardening. Representative volume element (RVE) is used for this analysis. The element consists of a combined square field composed of a solid circular cylinder fiber and matrix in plane strain condition. Elastic analysis is carried out using Airy stress function and Michell solution. Unknown coefficients of the Airy stress function are determined by satisfying boundary conditions as well as continuity conditions. The governing equation of plastic zone is... 

In recent years, industrial robots have been greatly used as orienting devices in industry, especially in the automotive, shipbuilding and aerospace manufacturing industries. Industrial robots are gradually finding their niche in manufacturing, replacing less universal and more expensive CNC-machines. Application area of robots is constantly growing; they begin to be used for the assembly, pick-and-place operations, machining operations and etc. The use of robots for machining operations is growing because of their flexibility to perform a broad spectrum of tasks at a lower cost when compared with machine tools. Recently, parallel robots have attracted more and more researchers’ attention in... 

Cerebral Palsy is the most common motor disability in childhood. It’s caused by an injury or impaired development of brain. As result, CP children have disability in motor system. All people with cerebral palsy have problem with movement. The symptoms of CP vary from person to person. Therefore, gait analysis was used to investigate those child’s problems and help therapist to find better therapy. Given that, we analyze stance phase of gait cycle of CP children. Also, we calculate and compare variability between traditional development (TD) children and CPs to find a better understanding of how central nerves system (CNS) work. Kinematic Data during walking were collected from 100 CP and TD... 

The primary objective of this dissertation is to obtain a mechanism from the family of 5-dof parallel mechanisms of type 3T2R which gains the advantages of higher kinematic performance, low coupling of motion, and simple kinematics and control commands. Based on this aim, at first a method for structural synthesis of this type of mechanisms is introduced. The method is based on the theory of linear transformation and a geometrical analysis. By using this method, a set of novel 5-dof 3T2R parallel mechanism are introduced for the first time in the literature. In order to compare the designed mechanisms and to identify the promising ones, some important criteria which are a) low coupling... 

The purpose of this study is to evaluate the performance of the optimized conditional source-term estimation approach. This model was first implemented in a computational fluid dynamics code, and then the Bernstein expansion was used to optimize it. For validation, two pre-mixed turbulent flames with different turbulence intensity and equivalence ratios were modeled with the optimized and RANS model. The results were obtained for mass fraction of the main and intermediate species, velocity and temperature examined in different sections. In the first flame, the turbulence intensity is low, and the flame is in the flamelet regimes; As a result, the results obtained with the optimized model are... 

In this project the goal is to study where, when and how the cracks in the steel connection plate between beam and column initiate and how far would the crack grow before failure and how to detect crack initiation by utilizing piezoelectric sensors. In this analysis piezoelectric is placed in line of crack propagation for sensing strain and changing it to voltage. A thin plate with edge notch which is an ideal model of typical beam to column connection is assumed. The plate is subjected to a uniaxial uniform load. With the aid of ANSYS software, the plate is analyzed in both elastic and plastic stages. The strain-stress curve with kinematic hardening part is considered and modeled with... 

Manual material handling (MMH) activities are identified as risk factors for occupational low back pain (LBP). Task-related variables including load and posture characteristics are required as input into these models and tools for estimation of trunk external moment. Biomechanical modeling studies that aim to mathematically estimate low back loads currently need an inevitable parallel time-consuming in vivo study in an equipped laboratory to measure trunk posture under physical activities. Inertial sensors as a portable, accurate, almost inexpensive, and small device could be very helpful in order to capture the kinematic data of movement in human activities. My master thesis aims to... 

Today, obesity, as a major global health challenge, affects more than 30 percent of the world's population. To investigate the effect of obesity on spinal function, a common method is motion analysis (kinematic method). This method is based on the claim that the abnormal mechanical function of the spine is directly related to its abnormal motions.The aim of this study is to measure and compare the range of motions (RoMs) of different segments of the spine in all anatomical plates between obese and normal individuals, as well as to calculate and compare some motion rhythms between the lumbar spine and the pelvis in these two groups. Comparing the posture of the spine between obese and normal... 

Cable-driven parallel robots (CDPRs) form a class of robotic manipulator in which the actuation end-effector is transmitted through cables. Due to the unique characteristics and advantages of cable transmission, CDPRs have become increasingly studied in recent years. In this thesis, the study of Geometric Analysis and Dynamic Trajectory of a 5-DOF Cable-Suspended Spatial Parallel Robot is investigated. Geometric analysis is corresponds to the workspace on which the robot is designed. The design of cable mechanisms allows the robot to be used with appropriate configuration in various fields such as industry, medicine, etc. The study of CDPR design has been limited due to several reasons.... 

In this thesis, kinematic, dynamic modeling and simulation, and control of SQ15-06N industrial robot have been presented. This robot is mostly used in the painting industry. Studying the robot requires familiarity with the robot programming and the hardware used in the robot. In this research, robot characteristics such as repeatability, load carrying capacity and accessibility have been investigated. The principles of industrial robot programming and robot programming language have been studied. The use of simulation software is common due to cost savings, reduced time, no need for robots and controllers, and the ability to test programs in a virtual environment. For this purpose, the... 

Parkinson's disease is the most common progressive neurological disorder after Alzheimer, which is associated with motor disabilities. One of the most effective ways to improve patient’s condition with this disease, is rehabilitation.Assessment of the patient during rehabilitation is very important in order to give a better understanding of patient's status to the specialist, but qualitative assessment methods in traditional rehabilitation are ineffective in fast and accurate evaluation of the patient's condition; and because of their need for patient’s attendance in clinic, they will incur huge medical costs. Therefore, the purpose of the present study is to present a quantitative method to... 

Spinal cord injury (SCI) is one of the most important causes of disability in the youth and costs enormous expenses for the government. Most SCI subjects use wheelchair as their main way of locomotion while standing and walking can benefit them in various aspects. The role of lower extremity muscles has been investigated in paraplegic gait with active orthoses or in partial weight support condition. However, due to the large expenses of active orthoses, their application have been limited to clinical trials and yet most SCI individuals use traditional AFO and KAFO for walking. The role and significance of trunk and upper extremity muscles (TUEM) has been investigated only in balance...