Nonlinear contact and impact of revolute joints

2012 ◽  
Author(s):  
Rongqiang Liu ◽  
Jing Zhang ◽  
Hongwei Guo ◽  
Zongquan Deng
Keyword(s):  
Revolute Joints ◽  
Nonlinear Contact ◽  
Contact And Impact

scholarly journals Modeling in ADAMS of a 6R industrial robot

2018 ◽  
Vol 184 ◽  
pp. 02006
Author(s):  
Mariana Ratiu ◽  
Alexandru Rus ◽  
Monica Loredana Balas
Keyword(s):  
Dynamic Analysis ◽  
Industrial Robot ◽  
Kinematic Model ◽  
Future Research ◽  
Robot Motion ◽  
Cad Model ◽  
3D Cad ◽  
Revolute Joints ◽  
Real Model ◽  
Articulated Robot

In this paper, we present the first steps in the process of the modeling in ADAMS MBS of MSC software of the mechanical system of an articulated robot, with six revolute joints. The geometric 3D CAD model of the robot, identical to the real model, in the PARASOLID format, is imported into ADAMS/View and then are presented the necessary steps for building the kinematic model of the robot. We conducted this work, in order to help us in our future research, which will consist of kinematic and dynamic analysis and optimization of the robot motion.

A novel transition model for lubricated revolute joints in planar multibody systems

2015 ◽  
Vol 36 (3) ◽  
pp. 279-294 ◽  
Author(s):  
Pei Li ◽  
Wei Chen ◽  
Desheng Li ◽  
Rufei Yu
Keyword(s):  
Multibody Systems ◽  
Transition Model ◽  
Revolute Joints

Further results on advanced robust iterative learning control and modeling of robotic systems

2020 ◽  
pp. 095440622096599
Author(s):  
Mihailo P Lazarević ◽  
Petar D Mandić ◽  
Srđan Ostojić
Keyword(s):  
Iterative Learning Control ◽  
Feedback Linearization ◽  
Angular Displacement ◽  
Viscous Friction ◽  
Learning Control ◽  
Iterative Learning ◽  
Revolute Joints ◽  
General Order ◽  
Robotic Joints ◽  
The Time Domain

Recently, calculus of general order [Formula: see text] has attracted attention in scientific literature, where fractional operators are often used for control issues and the modeling of the dynamics of complex systems. In this work, some attention will be devoted to the problem of viscous friction in robotic joints. The calculus of general order and the calculus of variations are utilized for the modeling of viscous friction which is extended to the fractional derivative of the angular displacement. In addition, to solve the output tracking problem of a robotic manipulator with three DOFs with revolute joints in the presence of model uncertainties, robust advanced iterative learning control (AILC) is introduced. First, a feedback linearization procedure of a nonlinear robotic system is applied. Then, the proposed intelligent feedforward-feedback AILC algorithm is introduced. The convergence of the proposed AILC scheme is established in the time domain in detail. Finally, simulations on the given robotic arm system confirm the effectiveness of the robust AILC method.

A planar reconfigurable linear rigid-body motion linkage with two operation modes

2014 ◽  
Vol 228 (16) ◽  
pp. 2985-2991 ◽  
Author(s):  
Guangbo Hao ◽  
Xianwen Kong ◽  
Xiuyun He
Keyword(s):  
Rigid Body ◽  
Single Mode ◽  
Rigid Body Motion ◽  
Body Motion ◽  
Reference Guide ◽  
Revolute Joints ◽  
Operation Modes ◽  
Straight Line ◽  
Motion Stage ◽  
Motion Mode

A planar reconfigurable linear (also rectilinear) rigid-body motion linkage (RLRBML) with two operation modes, that is, linear rigid-body motion mode and lockup mode, is presented using only R (revolute) joints. The RLRBML does not require disassembly and external intervention to implement multi-task requirements. It is created via combining a Robert’s linkage and a double parallelogram linkage (with equal lengths of rocker links) arranged in parallel, which can convert a limited circular motion to a linear rigid-body motion without any reference guide way. This linear rigid-body motion is achieved since the double parallelogram linkage can guarantee the translation of the motion stage, and Robert’s linkage ensures the approximate straight line motion of its pivot joint connecting to the double parallelogram linkage. This novel RLRBML is under the linear rigid-body motion mode if the four rocker links in the double parallelogram linkage are not parallel. The motion stage is in the lockup mode if all of the four rocker links in the double parallelogram linkage are kept parallel in a tilted position (but the inner/outer two rocker links are still parallel). In the lockup mode, the motion stage of the RLRBML is prohibited from moving even under power off, but the double parallelogram linkage is still moveable for its own rotation application. It is noted that further RLRBMLs can be obtained from the above RLRBML by replacing Robert’s linkage with any other straight line motion linkage (such as Watt’s linkage). Additionally, a compact RLRBML and two single-mode linear rigid-body motion linkages are presented.

Experimental evaluation of time-varying impulse shaping with a two-link flexible manipulator

Robotica ◽  
1996 ◽  
Vol 14 (3) ◽  
pp. 339-345 ◽  
Author(s):  
Jung-Keun Cho ◽  
Youn-Sik Park
Keyword(s):  
Vibration Reduction ◽  
Vertical Plane ◽  
Joint Stiffness ◽  
Flexible Manipulator ◽  
Input Shaping ◽  
Time Varying ◽  
Modal Properties ◽  
Revolute Joints ◽  
Point Motion ◽  
Point To Point

SUMMARYIn the authors' previous paper,10 an input shaping method was presented to reduce motion-induced vibrations effectively for various classes of flexible systems. In this paper, the effectiveness of the shaping method is experimentally demonstrated with a two-link flexible manipulator systemThe manipulator for experiments includes two revolute joints and two flexible links, and moves on a vertical plane under gravity. An analytic model is developed considering the flexibility of the system and its joint stiffness in order to derive an appropriate estimation of dynamic modal properties. The input shaping method used in this work utilizes time-varying modal properties obtained from the model instead of the conventional input shaping method which employs time-invariant modal properties. A point-to-point motion is tested in order to show the effectivess of the proposed shaping method in vibration reduction during and after a given motion. The given reference trajectories are shaped to suppress the motion induced vibration. The test results demonstrate that the link vibration can be greatly suppressed during and after a motion, and the residual vibration reduction was observed more than 90% by employing this time-varying impulse shaping technique.

Design and Virtual Prototyping of Rehabilitation Aids

1997 ◽  
Author(s):  
Venkat Krovi ◽  
Vijay Kumar ◽  
G. K. Ananthasuresh ◽  
Jean-Marc Vezien
Keyword(s):  
Virtual Prototyping ◽  
Assistive Devices ◽  
Cad Model ◽  
Mechanism Synthesis ◽  
Design And Optimization ◽  
Revolute Joints ◽  
Synthesis Design ◽  
Serial Chain

Abstract This paper presents a paradigm for virtual prototyping of a class of one-of-a-kind assistive devices that can be customized to the human user. This class consists of passive, articulated mechanical aids for manipulation that are physically coupled to the user. We address the mechanism synthesis, design and optimization and its evaluation in a virtual prototyping environment that consists of a CAD model of the product and a customized model of the human user. In addition, we develop the theory and methodology for designing planar serial chain mechanisms with revolute joints coupled by cable-pulley transmissions. As an illustrative example, we consider the design and prototyping of a customized feeding aid for quadriplegics.

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