scholarly journals Simultaneous Kinematic and Contact Force Modeling of a Human Finger Tendon System Using Bond Graphs and Robotic Validation

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
James A. Tigue ◽  
Raymond J. King ◽  
Stephen A. Mascaro
Keyword(s):  
Bond Graph ◽  
Contact Forces ◽  
Free Motion ◽  
Force Transmission ◽  
Bond Graphs ◽  
Moment Arms ◽  
Static Contact ◽  
Surface Contact ◽  
Bond Graph Modeling ◽  
Contact Experiments

Abstract This paper aims to use bond graph modeling to create the most comprehensive finger tendon model and simulation to date. Current models are limited to either free motion without external contact or fixed finger force transmission between tendons and fingertip. The forward dynamics model, presented in this work, simultaneously simulates the kinematics of tendon-finger motion and contact forces of a central finger given finger tendon inputs. The model equations derived from bond graphs are accompanied by nonlinear relationships modeling the anatomical complexities of moment arms, tendon slacking, and joint range of motion (ROM). The structure of the model is validated using a robotic testbed, Utah's Anatomically correct Robotic Testbed (UART) finger. Experimental motion of the UART finger during free motion (no external contact) and surface contact are simulated using the bond graph model. The contact forces during the surface contact experiments are also simulated. On average, the model was able to predict the steady-state pose of the finger with joint angle errors less than 6 deg across both free motion and surface contact experiments. The static contact forces were accurately predicted with an average of 11.5% force magnitude error and average direction error of 12 deg.

Some Key Issues in Using Bond Graphs and Genetic Programming for Mechatronic System Design

2001 ◽  
Author(s):  
R. C. Rosenberg ◽  
E. D. Goodman ◽  
Kisung Seo
Keyword(s):  
Genetic Programming ◽  
System Design ◽  
Design Space ◽  
Bond Graph ◽  
Mechatronic System ◽  
Bond Graphs ◽  
Mechatronic Systems ◽  
Energy Behavior ◽  
Key Issues ◽  
Bond Graph Modeling

Abstract Mechatronic system design differs from design of single-domain systems, such as electronic circuits, mechanisms, and fluid power systems, in part because of the need to integrate the several distinct domain characteristics in predicting system behavior. The goal of our work is to develop an automated procedure that can explore mechatronic design space in a topologically open-ended manner, yet still find appropriate configurations efficiently enough to be useful. Our approach combines bond graphs for model representation with genetic programming for generating suitable design candidates as a means of exploring the design space. Bond graphs allow us to capture the common energy behavior underlying the several physical domains of mechatronic systems in a uniform notation. Genetic programming is an effective way to generate design candidates in an open-ended, but statistically structured, manner. Our initial goal is to identify the key issues in merging the bond graph modeling tool with genetic programming for searching. The first design problem we chose is that of finding a model that has a specified set of eigenvalues. The problem can be studied using a restricted set of bond graph elements to represent suitable topologies. We present the initial results of our studies and identify key issues in advancing the approach toward becoming an effective and efficient open-ended design tool for mechatronic systems.

Bond Graph Modeling and Simulating of 3 RPR Planar Parallel Manipulator

2014 ◽  
Author(s):  
Cheng Yin ◽  
Shengqi Jian ◽  
Md. Hassan Faghih ◽  
Md. Toufiqul Islam ◽  
Luc Rolland
Keyword(s):  
Parallel Manipulator ◽  
High Speed ◽  
Reference Frames ◽  
Bond Graph ◽  
Dynamics Simulation ◽  
Bond Graphs ◽  
End Effector ◽  
Planar Parallel Manipulator ◽  
Bond Graph Modeling ◽  
Graph System

A 3-RPR planar parallel robot is a kind of planar mechanisms, which can work at high speed, with high accuracy and high rigidity. In this paper, a multi-body bond graph system will be built for the 3-RPR planar parallel manipulator (PPM), along with 3 PID controllers which give commands to 3 DC motors respectively. The advantage of bond graphs is that they can integrate different types of dynamics systems, the manipulator, the control and the motor can be modelled and simulated altogether in the same process. Bond graph will be established for each rigid body with body-fixed coordinate’s reference frames, which are connected with parasitic elements (damping and compliance) to each other. The PID set-point signals are generated by the explicit inverse kinematic equations. The 3 prismatic lengths constitute the measured feedback signals. In order to make the end-effector reach the ideal position with target orientation, the three links should reach the target lengths simultaneously. In this study, the dynamics simulation of 3-RPR PPM is conducted after building the bond graph system. As the 3 motors are working simultaneously and independently, the end-effector will arrive to the expected position. Finally, the bond graph and control system are validated with the compiled results and 3D animation. Force plot and torque plot will be generated as dynamics performance. Moreover, kinematics of manipulators are also calculated using bond graph. Eventually, bond graphs are shown to be effective in solving not only dynamic but also kinematic problems.

Lagrangian Bond Graphs for Solid Continuum Dynamics Modeling

1994 ◽  
Vol 116 (2) ◽  
pp. 178-192 ◽  
Author(s):  
E. P. Fahrenthold ◽  
J. D. Wargo
Keyword(s):  
Finite Element ◽  
Bond Graph ◽  
Dynamics Modeling ◽  
Bond Graphs ◽  
Element Discretization ◽  
Large Order ◽  
Wide Range ◽  
Bond Graph Modeling ◽  
Continuum Dynamics ◽  
Fixed Bond

The limitations of existing continuum bond graph modeling techniques have effectively precluded their use in large order problems, where nonrepetitive graph structures and causal patterns are normally present. As a result, despite extensive publication of bond graph models for continuous systems simulations, bond graph methods have not offered a viable alternative to finite element analysis for the vast majority of practical problems. However, a new modeling approach combining Lagrangian (mass fixed) bond graphs with a selected finite element discretization scheme allows for direct simulation of a wide range of large order solid continuum dynamics problems. With appropriate modifications, including the use of Eulerian (space fixed) bond graphs, the method may be extended to include fluid dynamics modeling.

Modeling and Analysis of Soft Contact in Robotic Grasping Using Bond Graph Methods

2011 ◽  
Vol 189-193 ◽  
pp. 1786-1792
Author(s):  
A. Khurshid ◽  
A. Ghafoor ◽  
M.A. Malik
Keyword(s):  
Viscoelastic Material ◽  
Bond Graph ◽  
Contact Forces ◽  
System Stability ◽  
Modeling And Analysis ◽  
Graph Modeling ◽  
Novel Approach ◽  
Bond Graph Modeling ◽  
The Stability ◽  
Soft Finger

Soft fingers contribute to dexterous grasping on account of the area contact and high friction involved. This paper presents a novel approach in modeling of soft contacts between soft fingertip and object using viscoelastic material and analyses its characteristics employing BondGraph Methods (BGM). The fingers are made viscoelastic by using springs and dampers. Detailed bond graph modeling of the contact phenomenon with two soft-finger contacts considered to be placed against each other on the opposite sides of the grasped object as is generally the case in a manufacturing environment is presented. The stiffness of the springs is exploited in order to achieve the stability in the soft-grasping which includes friction between the soft finger contact surfaces and the object. It is shown in the paper that the system stability depends on the viscoelastic material properties of the soft interface. Method of root locus is used to analyze this phenomenon. The paper shows how the weight of the object moving downward is controlled by the friction between the fingers and the object during the application of contact forces by varying the damping and the stiffness in the soft finger.

Constitutive and Modulation Structure in Bond Graph Modeling

1988 ◽  
Vol 110 (4) ◽  
pp. 395-402 ◽  
Author(s):  
J. J. Beaman ◽  
R. C. Rosenberg
Keyword(s):  
Energy State ◽  
Bond Graph ◽  
State Function ◽  
Physical Domain ◽  
Physical Realization ◽  
Additional Structure ◽  
Bond Graphs ◽  
Graph Modeling ◽  
Bond Graph Modeling ◽  
Model Equations

In this paper, we investigate additional structure that might be put on bond graphs in order that (1) a bond graph has a physical realization and (2) physical realizations have bond graph within an appropriate physical domain. In particular, restrictions are proposed on the allowed form for the constitutive laws for energy storing and dissipative elements and the allowed form for the modulation of coupling elements. This added structure is proposed to ensure the existence of an energy state function, passivity, unique solutions to the model equations, and to preserve the signal nature of modulation.

Bond Graph Sign Conventions

1975 ◽  
Vol 97 (2) ◽  
pp. 184-188 ◽  
Author(s):  
A. S. Perelson
Keyword(s):  
Graph Model ◽  
Bond Graph ◽  
Equivalence Classes ◽  
Parameter System ◽  
Bond Graphs ◽  
Lumped Parameter ◽  
Oriented Object

The lack of arbitrariness in the choice of bond graph sign conventions is established. It is shown that an unoriented bond graph may have no unique meaning and that with certain choices of orientation a bond graph may not correspond to any lumped parameter system constructed from the same set of elements. Network interpretations of these two facts are given. Defining a bond graph as an oriented object leads to the consideration of equivalence classes of oriented bond graphs which represent the same system. It is also shown that only changes in the orientation of bonds connecting 0-junctions and 1-junctions can lead to changes in the observable properties of a bond graph model.

Dynamic Model of Dual Clutch Lever-Based Electromechanical Actuator

2011 ◽  
Author(s):  
Vladimir Ivanovic´ ◽  
Josˇko Deur ◽  
Milan Milutinovic´ ◽  
H. Eric Tseng
Keyword(s):  
Experimental Data ◽  
Dynamic Model ◽  
Model Validation ◽  
Bond Graph ◽  
Test Rig ◽  
Electromechanical Actuator ◽  
Actuator Dynamics ◽  
Operating Modes ◽  
Graph Modeling ◽  
Bond Graph Modeling

The paper presents a dynamic model of a dual clutch lever-based electromechanical actuator. Bond graph modeling technique is used to describe the clutch actuator dynamics. The model is parameterized and thoroughly validated based on the experimental data collected by using a test rig. The model validation results are used for the purpose of analysis of the actuator behavior under typical operating modes.

scholarly journals Role of capillary adhesion in the friction peak during the tacky transition

Friction ◽  
2021 ◽  
Author(s):  
Tianyan Gao ◽  
Jiaxin Ye ◽  
Kaisen Zhang ◽  
Xiaojun Liu ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Indentation Depth ◽  
Normal Force ◽  
Normal Load ◽  
Pdms Film ◽  
Capillary Adhesion ◽  
Static Contact ◽  
Van Der Waals Attraction ◽  
Contact Experiments

AbstractThe friction peak that occurs in tire-road sliding when the contact changes from wet to dry was previously attributed to capillary cohesion, van der Waals attraction, and surface roughness, but the detailed mechanisms have yet to be revealed. In this study, friction and static contact experiments were conducted using a custom-built in situ optical microtribometer, which allowed us to investigate the evolution of the friction, normal load, and contact area between a polydimethylsiloxane (PDMS) film and a silicon nitride ball during water volatilization. The friction coefficient increased by 100%, and the normal force dropped by 30% relative to those in the dry condition during the wet-to-dry transition. In static contact experiments, the probe indentation depth increased, and the normal load decreased by ∼60% as the water evaporated. Combining the friction and static contact results, we propose that the large friction peak that appeared in this study can be attributed to the combined effects of increased adhesive capillary force and increased plowing during the wet-to-dry transition.

scholarly journals Analysing and simulating energy-based models in biology using BondGraphTools

2021 ◽  
Author(s):  
Peter Cudmore ◽  
Michael Pan ◽  
Peter J. Gawthrop ◽  
Edmund J. Crampin
Keyword(s):  
Systems Biology ◽  
Mathematical Models ◽  
Bond Graph ◽  
Experimental Measurements ◽  
Bond Graphs ◽  
Graph Models ◽  
Conservation Of Energy ◽  
Conservation Of Mass ◽  
Physical Systems ◽  
Complex Interactions

AbstractLike all physical systems, biological systems are constrained by the laws of physics. However, mathematical models of biochemistry frequently neglect the conservation of energy, leading to unrealistic behaviour. Energy-based models that are consistent with conservation of mass, charge and energy have the potential to aid the understanding of complex interactions between biological components, and are becoming easier to develop with recent advances in experimental measurements and databases. In this paper, we motivate the use of bond graphs (a modelling tool from engineering) for energy-based modelling and introduce, BondGraphTools, a Python library for constructing and analysing bond graph models. We use examples from biochemistry to illustrate how BondGraphTools can be used to automate model construction in systems biology while maintaining consistency with the laws of physics.

Sign in / Sign up

Export Citation Format

Share Document