Showing papers by "Doina Pisla published in 2009"

Development of a Control System for a Parallel Robot Used in Minimally Invasive Surgery

Abstract: For the use of robotic systems in applications like minimally invasive surgical procedures, adequate control is necessary. Because of the direct interaction with the patient, safety is a critical aspect in robot control. This paper presents a simple and robust, open-architecture control system for an innovative parallel robot designed for the positioning of the laparoscopic instrument in minimally invasive surgery. The use of intelligent actuators, modular programming and CANOpen data transmission protocol, enabled the development of a simple, compact and fast control system that can be extended for the command of multiple robotic arms. The developed user interface with the specific commands used during the surgical procedures and the experimental model of the parallel robot are presented.

Kinematics and design of two variants of a reconfigurable parallel robot

Abstract: In order to reach the desired results solutions must be different for each individual industrial application. For solving certain tasks special mechanisms should be developed for each application. Reconfigurable robots can be defined as a specific category of robots in which their components (individual joints and links) can be assembled in different configurations and geometries. In this paper several aspects of the kinematics and design for two variants of reconfigurable parallel robots are presented and some kinematics simulation results for these reconfigurable parallel robots are illustrated as well.

Kinematical Analysis and Design of a New Surgical Parallel Robot

Abstract: Robots in surgery are used because of their superior advantages: improved accuracy, tremor elimination etc, which exceeds human capabilities. Unlike serial robots, parallel robots offer higher stiffness, reduced masses in motion, higher rigidity, all of these leading more precise manipulations that fit medical applications. In this paper, a new innovative parallel structure for laparoscopy is presented. It is studied the forward and inverse kinematics, the singularities, it is generated the workspace and are presented some simulation results.

Liver 3D Reconstruction Modalities – The First Step toward a Laparoscopic Liver Surgery Simulator

Abstract: Three-dimensional reconstructions of the liver will be used to develop a new laparoscopic liver surgery simulator. The first step on this way is to develop a realistic virtual model from CT-scans, and then, using finite element analysis, consistency will be associated with different structures and tumors within the liver. This study aims to find the best way to obtain a 3D liver reconstruction with inner structures which will be used later for a finite element analysis. The protocols for slices acquisition from CT-scanner are presented. Also a comparison between reconstructions with dedicated software from CT-scanner providers (method 1) and image reconstruction software (method 2) are performed. The first method obtains 3D reconstructions faster than the second method, but these images cannot be used for a finite element analysis. On the other hand the second method obtains 3D reconstructions harder, but these images can be used for finite element analysis and utilized later to develop a virtual environment for integration in laparoscopic simulator.

The Influence of Motion Mode and Friction on the Dynamics of a Parallel Robot Used for Orientation Applications

Abstract: This paper presents a method for the dynamical modeling of a 3-DOF parallel mechanism without and with friction used for orientation applications (TV satellite antenna or sun tracker). Parallel robots have some advantages over serial ones such as higher stiffness, very good accuracy, high speeds and accelerations, a better weight over payload rate. Using a numerical and graphical simulation, the diagrams for the dynamics representation are computed. In the paper the influence of the task duration and friction on the joint torques is studied.