Sharif Digital Repository

Featuring a nonlinear novel design, Gimbal transmission, is a replacement for traditional robotic joints like gearboxes and revolute joints. This mechanism is one of the most recent types of nonlinear direct transmission (DT) methods in robots. As an alternative for traditional drive methodologies - herein called direct drive transmission (DD) methods, DT provides dynamic coupling and joint interaction attenuation while its capability to be adjusted for a desired task space point, smooth input-output characteristic, and varying reduction ratio lead to a desired force and motion behavior for the whole manipulator. In this paper, design optimization of a gimbal mechanism used as a replacement... 

This paper presents design and analysis of a cabledriven mechanism for a spherical laparoscopy surgical robot manufactured at the Research Center for Science and Technology in Medicine. The design is featured by two types of 'idler pulleys', which allow change of cables' plane of motion in spherical workspace. This robot suffers from back-lash and high friction due to the usage of motor and gear-box in each joint. In order to find a precise and optimal design, the paper studies various designs of cable robots, considering pulleys and cable arrangements, as well as pre-tensioning methods. Final scheme introduces two series of pulleys for each DOF, which transmits power from motors located on...