scholarly journals Optimal Multi-Manipulator Arm Placement for Maximal Dexterity during Robotics Surgery

2021 ◽  
Author(s):  
Mingwei Xu ◽  
James Di ◽  
Nikhil Das ◽  
Michael C. Yip
Keyword(s):  
Manipulator Arm

Experimental Characterization of a Flexible Two-Link Manipulator Arm

1993 ◽  
Author(s):  
Randall L. Mayes ◽  
G. Richard Eisler
Keyword(s):  
Element Model ◽  
Input Voltage ◽  
Analytical Models ◽  
Experimental Characterization ◽  
Frequency Range ◽  
Flexible Links ◽  
Beam Elements ◽  
Output Torque ◽  
Manipulator Arm

Abstract Experiments were performed to verify the analytical models for a robotic manipulator with two flexible links. A finite element model (FEM) employing two-dimensional beam elements was used to model the structure. A proportional model relating input voltage to output torque was used for both hub and elbow joint motors. With some minor adjustments to the link stiffness, the FEM modal frequencies matched the experimentally extracted frequencies within 1.5%. However the voltage-torque relationship for the hub motor was found to exhibit dynamics in the frequency range of interest.

Analysis of Elastic Motion Stability of Flexible Manipulator Arm Based on Lyapunov Stability Theory

2014 ◽  
Vol 620 ◽  
pp. 321-329
Author(s):  
Guang Rui Liu ◽  
Wen Bo Zhou ◽  
Rong Fu Liu
Keyword(s):  
Lyapunov Stability ◽  
Stability Theory ◽  
Lagrange Equation ◽  
Lyapunov Stability Theory ◽  
The State ◽  
Flexible Manipulator ◽  
Rotational Inertia ◽  
Control Input ◽  
Motion Stability ◽  
Manipulator Arm

In order to study the elastic motion stability of flexible manipulator arm , to compute the maximum dynamic allowable payload , the partial differential equation of elastic motion of the flexible manipulator arm is solved using the method of Laplace transformation , the dynamic model of flexible manipulator arm carried addition mass on its end position is established ,simplified and truncated using Lagrange equation . the state space expression is established with the state variable and control input and output variable designated , the elastic motion stability rule is built upon and simplified using Lyapunov stability theory . The influence of the end position addition mass and articulation rotational inertia of flexible manipulator arm on its elastic motion stability is analyzed using the stability rule , and the dynamic maximum allowable payload of flexible manipulator arm on its end position is computed in order to guarantee its elastic motion stability . this study is important to the design of robot mechanical manipulator and corresponding drive control system .

Modular Advantage and Kinematic Decoupling in Gravity Compensated Robotic Systems

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Nick Eckenstein ◽  
Mark Yim
Keyword(s):  
Vertical Plane ◽  
Robotic Systems ◽  
Gravity Compensation ◽  
Pulley System ◽  
Free Length ◽  
Low Profile ◽  
Serial Chain ◽  
Manipulator Arm ◽  
Spring Method ◽  
Position And Orientation

Two new designs for gravity compensated modular robotic systems are presented and analyzed. The gravity compensation relies on using zero-free-length springs approximated by a cable and pulley system. Simple yet powerful parallel four-bar modules enable the low-profile self-contained modules with sequential gravity compensation using the spring method for motion in a vertical plane. A second module that is formed as a parallel six-bar mechanism adds a horizontal motion to the previous system that also yields a complete decoupling of position and orientation of the distal end of a serial chain. Additionally, we introduce the concept of vanishing effort where as the number of modules that comprise an articulated serial chain increases, the actuation authority required at any joint reduces. Essentially, this results in a method for distributing actuation along the length of an articulated chain. Prototypes were designed and constructed validating the analysis and accomplishing the functions of a general serial-type manipulator arm.

Robotic location of underground chemical sources

Robotica ◽  
2004 ◽  
Vol 22 (1) ◽  
pp. 109-115 ◽  
Author(s):  
R. Andrew Russell
Keyword(s):  
Robot Manipulator ◽  
Search Algorithm ◽  
Chemical Vapour ◽  
Coarse Sand ◽  
Land Mines ◽  
Factors Affecting ◽  
Sensory Environment ◽  
Manipulator Arm ◽  
Unexploded Ordinance ◽  
Sensor Probe

This paper describes current progress in a project to develop robotic systems for locating underground chemical sources. There are a number of economic and humanitarian applications for this technology. Finding unexploded ordinance, land mines, and sources of leaks from pipes and tanks are some examples. Initial experiments were conducted using an ethanol chemical source buried in coarse sand. To gain an understanding of the sensory environment that would be experienced by a robot burrowing through the ground, the factors affecting transport of chemical vapour through soil were investigated. A robot search algorithrn was then developed for gathering chemical gradient inforrnation and using this to guide a robot towards the source. Experiments were performed using a chemical sensing probe positioned by a UMI RTX robot manipulator arm. The resulting system was successful in locating a source of ethanol vapour buried in sand. This paper includes details of experiments to characterise the sand used in this project, the robot search algorithm, sensor probe and results of source location trials.

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