Planar Multi-body Dynamics of a Tracked Vehicle using Imaginary Wheel Model for Tracks

2017 ◽  
Vol 67 (4) ◽  
pp. 460
Author(s):  
Ilango Mahalingam ◽  
Chandramouli Padmanabhan
Keyword(s):  
Interaction Model ◽  
Differential Algebraic Equations ◽  
Rigid Bodies ◽  
Contact Forces ◽  
Algebraic Equations ◽  
Tracked Vehicle ◽  
The Road ◽  
Wheel Model ◽  
Longitudinal Slip ◽  
Multi Body

<p class="p1">Off-road vehicles achieve their mobility with the help of a track system. A track has large number of rigid bodies with pin joints leading to computational complexity in modelling the dynamic behaviour of the system. In this paper, a new idea is proposed, where the tracks are replaced by a set of imaginary wheels connected to the road wheels using mechanical links. A non-linear wheel terrain interaction model considering longitudinal slip is used to find out the normal and tangential contact forces. A linear trailing arm suspension, where a road arm connecting the road wheel and chassis with a rotational spring and damper system is considered. The differential algebraic equations (DAEs) from the multi-body model are derived in Cartesian coordinates and formulated using augmented formulation. The augmented equations are solved numerically using appropriate stabilisation techniques. The novel proposition is validated using experimental measurements done on a tracked vehicle.</p>

Optimization of the characteristic angles of both front and rear McPherson suspensions on a circular track using multi-body numerical simulation

2009 ◽  
Vol 223 (9) ◽  
pp. 1119-1132 ◽  
Author(s):  
G Virzì Mariotti ◽  
G Ficarra
Keyword(s):  
Numerical Simulation ◽  
Contact Forces ◽  
Roll Motion ◽  
The Road ◽  
Virtual Vehicle ◽  
Circular Track ◽  
Characteristic Values ◽  
Optimal Values ◽  
Multi Body

The research reported in this paper aims to simulate the road-holding of a virtual vehicle using multi-body simulation to estimate both the contact forces between the tyre and ground and the roll motion when cornering. Furthermore, the effect of the characteristic angles on the variation in the forces of the tyre in contact with the ground is studied to determine optimal values for these angles. Emphasis is placed on an average-class vehicle, of which both the external dimensions and mass are chosen appropriately, with a McPherson suspension mounted on both the front and the rear. The characteristic values of the camber and toe-in angles, in both the front and the rear, are optimized for motion in the curve under constant traction. The results of numerical simulation are compared with results from the theory of stability in the curve (given the vertical configuration of the vehicle).

Multi-Body Modeling of Human Musculoskeletal System for an Exercise Therapy Method and its Verification

2013 ◽  
Author(s):  
Munehiro Michael Kayo ◽  
Yoshiaki Ohkami
Keyword(s):  
Exercise Therapy ◽  
Musculoskeletal System ◽  
Human Body ◽  
Structural Model ◽  
Force Plate ◽  
Rigid Bodies ◽  
Contact Forces ◽  
Estimation Of Parameters ◽  
Human Body Model ◽  
Multi Body

The objective of this paper is to establish a concise structural model of the human musculoskeletal system (HMS) that can be applied to an exercise therapy that treats malfunctions or distortions of the human body. There exist a number of traditional exercise therapy methods in Japan and China, but any systematic approaches for learning, coaching or training are not found to the best of the author’s knowledge. Among such approaches, we deal with an exercise therapy called Somatic Balance Restoring Therapy (SBRT) in which a patient executes a series of non-invasive and painless motions in face-up/down laid posture. Although thousands of results have been piled up in a fixed-format data base, justification for the SBRT has not been provided in bio/mechanical engineering sense. The purpose of modeling is a first step for this holistic approach. For such reasons, the model must be useful and uncomplicated for therapists to identify the problematic areas of the human body with adequate visualization while maintaining a theoretical thoroughness in mechanics or dynamics. To bridge multi-body dynamics and the SBRT, we have utilized a human body model with a collection of joint connected 15 rigid bodies in a topological tree configuration as used for humanoid robot with 80 Degrees-of-Freedom (DOF). In order to achieve the purpose stated above, we have developed a static force/torque balance equation for each body element. In addition, we will describe modeling processes, derivation of static equations, and estimation of parameters/states and verification based on the analysis of the FPS experimental data, and contact forces are parameterized with quantitative values to be given by the Force Plate System (FPS), installed at CARIS at the University of British Columbia (UBC).

scholarly journals Mathematical Formulation of Soft-Contact Problems for Various Rheological Models of Damper

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Wiesław Grzesikiewicz ◽  
Artur Zbiciak
Keyword(s):  
Mathematical Formulation ◽  
Contact Problems ◽  
Differential Algebraic Equations ◽  
Contact Forces ◽  
Algebraic Equations ◽  
Unilateral Constraints ◽  
Soft Contact ◽  
Rheological Models ◽  
Model Interaction ◽  
Time Histories

The paper deals with analysis of selected soft-contact problems in discrete mechanical systems. Elastic-dissipative rheological schemes representing dampers as well as the notion of unilateral constraints were used in order to model interaction between colliding bodies. The mathematical descriptions of soft-contact problems involving variational inequalities are presented. The main finding of the paper is a method of description of soft-contact phenomenon between rigid object and deformable rheological structure by the system of explicit nonlinear differential-algebraic equations easy for numerical implementation. The results of simulations, that is, time histories of displacements and contact forces as well as hysteretic loops, are presented.

On the Use of the HHT Method in the Context of Index 3 Differential Algebraic Equations of Multibody Dynamics

2005 ◽  
Author(s):  
Dan Negrut ◽  
Rajiv Rampalli ◽  
Gisli Ottarsson ◽  
Anthony Sajdak
Keyword(s):  
Differential Algebraic Equations ◽  
Algebraic Equations ◽  
Body System ◽  
Vehicle Model ◽  
Good Efficiency ◽  
Numerical Integrator ◽  
Starting Point ◽  
Implementation Aspects ◽  
Multi Body ◽  
Simulation Package

The paper presents theoretical and implementation aspects related to a new numerical integrator available in the 2005 version of the MSC.ADAMS/Solver C++. The starting point for the new integrator is the Hilber-Hughes-Taylor method (HHT, also known as α-method) that has been widely used in the finite element community for more than two decades. The method implemented is tailored to answer the challenges posed by the numerical solution of index 3 Differential Algebraic Equations that govern the time evolution of a multi-body system. The proposed integrator was tested with more than 1,600 models prior to its release in the 2005 version of the simulation package MSC.ADAMS. In this paper an all-terrain-vehicle model with flexible chassis is used to prove the good efficiency and accuracy of the method.

Deep Learning of (Periodic) Minimal Coordinates for Multibody Simulations

2020 ◽  
Author(s):  
Andrea Angeli ◽  
Frank Naets ◽  
Wim Desmet
Keyword(s):  
Neural Network ◽  
Differential Algebraic Equations ◽  
Algebraic Equations ◽  
Multibody Model ◽  
Network Training ◽  
The Neural Network ◽  
Continuous Description ◽  
Minimal Coordinates ◽  
Reduced Space ◽  
Multi Body

Abstract Mechanical systems are typically described through multi-body models with redundant coordinates, related by imposed constraints, where the dynamics is expressed with Differential Algebraic Equations. Alternatively, for rigid models, it may be preferable to employ minimal coordinates that do not require additional constraints, thus leading to Ordinary Differential Equations. However, to reduce a general multibody model to minimal coordinates and perform the simulation in the reduced space, the mapping between the minimal coordinates and the full coordinates is required. In this work, it is proposed to approximate such mapping using a neural network. In order to avoid overfitting and guarantee a continuous description of the solution manifold, the multibody dynamics information are included in the neural network training. The particular case where periodic minimal coordinates are required is treated and validated. In general, the methodology can be used when the mapping is unknown such as for spatial mechanisms with closed loops.

Variational Analysis of a Two Link Slider-Crank Mechanism Using Polynomial Chaos Theory

2017 ◽  
Author(s):  
Paul S. Ryan ◽  
Sarah C. Baxter ◽  
Philip A. Voglewede
Keyword(s):  
Chaos Theory ◽  
Closed Loop ◽  
Polynomial Chaos ◽  
Differential Algebraic Equations ◽  
Algebraic Equations ◽  
Advantages And Disadvantages ◽  
Multi Body ◽  
Polynomial Chaos Theory ◽  
Body Dynamic ◽  
Crank Mechanism

Variation occurs in many closed loop multi-body dynamic (MBD) systems in the geometry, mass, or forces. Understanding how MBD systems respond to variation is imperative for the design of a robust system. However, simulation of how variation propagates into the solution is complicated as most MBD systems cannot be simplified into to a system of ordinary differential equations (ODE). This paper investigates polynomial chaos theory (PCT) as a means of quantifying the effects of uncertainty in a closed loop MBD system governed by differential algebraic equations (DAE). To demonstrate how PCT could be used, the motion of a two link slider-crank mechanism is simulated with variation in the link lengths. To validate and show the advantages and disadvantages of PCT in closed loop MBD systems, the PCT approach is compared to Monte Carlo simulations.

scholarly journals Two-Mode Resonator and Contact Model for Standing Wave Piezomotor

2001 ◽  
Author(s):  
Brian Andersen ◽  
Mogens Blanke ◽  
Jan Helbo
Keyword(s):  
Standing Wave ◽  
Contact Stiffness ◽  
Ritz Method ◽  
Differential Algebraic Equations ◽  
Contact Forces ◽  
Piezoelectric Motor ◽  
Algebraic Equations ◽  
Bending Mode ◽  
Resonance Frequencies ◽  
Mode Resonator

Abstract The paper presents a model for a standing wave piezoelectric motor with a two bending mode resonator. The resonator is modelled using Hamilton’s principle and the Rayleigh-Ritz method. The contact is modelled using the Lagrange Multiplier method under the assumption of slip and it is shown how to solve the set of differential-algebraic equations. Detailed simulations show resonance frequencies as function of the piezoelement’s position, tip trajectories and contact forces. The paper demonstrates that contact stiffness and stick should be included in such a model to obtain physically realistic results and a method to include stick is suggested.

Dynamic Simulation and Experimental Analysis on Ride Comfort Performance of Tracked Vehicle

2011 ◽  
Vol 105-107 ◽  
pp. 500-503
Author(s):  
Wen Rui Wang ◽  
Han Chen ◽  
Sai Du ◽  
Bo Yang
Keyword(s):  
Ride Comfort ◽  
Model Simulation ◽  
Influence Factors ◽  
Suspension System ◽  
Vehicle Suspension ◽  
Tracked Vehicle ◽  
The Road ◽  
Body Model ◽  
And Performance ◽  
Multi Body

A comprehensive nonlinear vehicle model of a tracked vehicle suspension is established by using multi-body dynamics software Recurdyn, which is used to be simulated ride comfort dynamic response. In the paper, the multi-body model dynamics vibration characters of vehicle suspension is simulated, which is accomplished by testing the model on the different roads (such as level-D,E&F Road) by different vehicle riding speed. The influence factors about ride comfort are found by the stimulation, which are the road level,the velocity of the vehicle and other parameters of the suspension system. The experiment about the vehicle ride comfort performance proves that using the multi-body model simulation in the paper could be helpful to select appropriate suspension system parameters in the structure and performance design about tracked vehicle suspension, which could give theory bases about suspension active controlling strategy of the suspension.

Dynamic Simulation of Dielectric Elastomer Actuated Multibody Systems

2016 ◽  
Author(s):  
T. Schlögl ◽  
S. Leyendecker
Keyword(s):  
Finite Element ◽  
Multibody Systems ◽  
Multibody System ◽  
Humanoid Robots ◽  
Differential Algebraic Equations ◽  
Rigid Bodies ◽  
Integration Scheme ◽  
Artificial Muscles ◽  
Algebraic Equations ◽  
Energy Behavior

A three-dimensional electro-mechanically coupled finite element model for dielectric elastomers is used to actuate multibody systems. This setting allows exploring the complex behavior of humanoid robots that are driven by artificial muscles instead of electrical drives. The coupling between the finite element muscle model and the rigid bodies is formulated at configuration level, where Lagrange multipliers account for constraint forces, leading to differential algebraic equations of index-3. A well-chosen set of redundant configuration variables for the multibody system avoids any rotational degrees of freedom and leads to linear coupling constraints. As a result, the coupling between the artificial muscles and the multibody system can be formulated in a very modular way that allows for easy future extension. The applied structure preserving time integration scheme provides excellent long time energy behavior. In addition, the index-3 system is solved directly with numerical accuracy, avoiding index reduction approximations.

Numerical Computation of Differential-Algebraic Equations for Non-Linear Dynamics of Multibody Systems Involving Contact Forces

1999 ◽  
Vol 123 (2) ◽  
pp. 272-281 ◽  
Author(s):  
B. Fox ◽  
L. S. Jennings ◽  
A. Y. Zomaya
Keyword(s):  
Multibody Systems ◽  
Virtual Work ◽  
Equations Of Motion ◽  
Variational Problems ◽  
Differential Algebraic Equations ◽  
Contact Forces ◽  
Algebraic Equations ◽  
Differential Algebraic Equation ◽  
Lagrange Equations ◽  
Constraint Equations

The well known Euler-Lagrange equations of motion for constrained variational problems are derived using the principle of virtual work. These equations are used in the modelling of multibody systems and result in differential-algebraic equations of high index. Here they concern an N-link pendulum, a heavy aircraft towing truck and a heavy off-highway track vehicle. The differential-algebraic equation is cast as an ordinary differential equation through differentiation of the constraint equations. The resulting system is computed using the integration routine LSODAR, the Euler and fourth order Runge-Kutta methods. The difficulty to integrate this system is revealed to be the result of many highly oscillatory forces of large magnitude acting on many bodies simultaneously. Constraint compliance is analyzed for the three different integration methods and the drift of the constraint equations for the three different systems is shown to be influenced by nonlinear contact forces.

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