Coupled Vertical-Lateral Dynamics of a Pneumatic Tired Vehicle: Part I—A Mathematical Model

1978 ◽  
Vol 100 (4) ◽  
pp. 311-318 ◽  
Author(s):  
N. S. Nathoo ◽  
A. J. Healey
Keyword(s):  
Mathematical Model ◽  
Euler Angle ◽  
System Model ◽  
Contact Interface ◽  
Frequency Range ◽  
Acceleration Response ◽  
Lateral Dynamics ◽  
Vehicle System ◽  
System Equations ◽  
Elastically Supported

A method is presented which permits the simulation of the coupled vertical and lateral rigid body vibration response of an automobile to roadway roughness inputs. A set of equations in matrix form is obtained for an assumed ten degree-of-freedom mathematical model of the vehicle-tire system using generalized linear and Euler angle coordinates. Kinematic relations for a rolling tire which treat it as an elastically supported string under tension are incorporated into the overall system model. Forces and moments that act in the tire-roadway contact interface are represented mathematically as a function of the parameters and response variables of the vehicle system. The nonlinear system equations are subsequently simplified in order to apply them to a vehicle moving along a straight roadway. The formulated model is shown to be adequate for predicting acceleration response in a frequency range of 0.1–10 Hz for the set of roadway test roadway sections considered in the present study.

Bond Graphs for Distributed System Models Admitting Mixed Causal Inputs

1980 ◽  
Vol 102 (2) ◽  
pp. 94-100 ◽  
Author(s):  
D. L. Margolis
Keyword(s):  
System Dynamics ◽  
Distributed System ◽  
System Model ◽  
Frequency Range ◽  
Bond Graphs ◽  
High Frequencies ◽  
System Models ◽  
System Equations

Bond graphs are used for finite mode representations of distributed system dynamics. As long as all inputs to the system are “efforts” in a causal sense, then no formulation problems exist. However, if some of the system inputs are causal “flows”, then differential causality will exist and extremely tedious, often impossible, algebraic loops must be solved to formulate system equations. A procedure is developed which avoids these algebraic problems by including additional modal compliance in the system model without its associated modal inertia. The result of this approach is a finite mode distributed system model, devoid of artificially induced high frequencies, extremely accurate in a chosen frequency range, and capable of interacting with other distributed system models. The procedure is demonstrated through example.

scholarly journals A Multiphase Flow in the Antroduodenal Portion of the Gastrointestinal Tract: A Mathematical Model

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
P. V. Trusov ◽  
N. V. Zaitseva ◽  
M. R. Kamaltdinov
Keyword(s):  
Mathematical Model ◽  
Gastrointestinal Tract ◽  
Multiphase Flow ◽  
Human Body ◽  
Digestive System ◽  
System Model ◽  
Food Density ◽  
Secretory Function ◽  
Functional Disorders ◽  
Food Particles

A group of authors has developed a multilevel mathematical model that focuses on functional disorders in a human body associated with various chemical, physical, social, and other factors. At this point, the researchers have come up with structure, basic definitions and concepts of a mathematical model at the “macrolevel” that allow describing processes in a human body as a whole. Currently we are working at the “mesolevel” of organs and systems. Due to complexity of the tasks, this paper deals with only one meso-fragment of a digestive system model. It describes some aspects related to modeling multiphase flow in the antroduodenal portion of the gastrointestinal tract. Biochemical reactions, dissolution of food particles, and motor, secretory, and absorbing functions of the tract are taken into consideration. The paper outlines some results concerning influence of secretory function disorders on food dissolution rate and tract contents acidity. The effect which food density has on inflow of food masses from a stomach to a bowel is analyzed. We assume that the future development of the model will include digestive enzymes and related reactions of lipolysis, proteolysis, and carbohydrates breakdown.

scholarly journals Starting generator driving torque modeling in the studies of synchronous starting of synchronous machines

2002 ◽  
Vol 15 (3) ◽  
pp. 399-408
Author(s):  
Zoran Stajic ◽  
Dragan Petrovic ◽  
Dusan Arnautovic
Keyword(s):  
Mathematical Model ◽  
Linear Function ◽  
Polynomial Approximation ◽  
System Model ◽  
Synchronous Machines ◽  
Model Function ◽  
Detailed Model ◽  
Pumped Storage ◽  
Driving Torque ◽  
Time Linear

The paper deals with significance of the starting generator (SG) driving torque modeling in the studies of synchronous starting of synchronous machines (SSSM). The detailed mathematical model of SSSM in reversible pumped storage plant (RPSP) "Bajina Basta" is derived. Because it is very difficult to include the detailed model of the SG turbine in the system model, function of SG driving torque is modeled approximately. The most frequent case in SSSM studies is its approximation with a time linear function, until it reaches the value that should provide rotating of both machine rotors with synchronous velocities, which is also used in the paper Afterwards, three different cases are considered: constant, linear and polynomial approximation in terms of SG rotor velocity. Numerical results obtained by applying developed models to a particular case of synchronous starting are compared with the corresponding experimental results. In this way, it is shown that the application of the most frequently used SG driving torque modeling leads to the erroneous results. The advantages of the polynomial approximation suggested in the paper and its validity is demonstrated.

Fault Diagnosis for Suspension Signal of Maglev Vehicle Based on Mathematical Model

2012 ◽  
Vol 190-191 ◽  
pp. 987-992 ◽  
Author(s):  
Ying Pu Cui ◽  
Long Hua She ◽  
Xiao Long Li ◽  
A Ming Hao
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Fault Diagnosis ◽  
System Model ◽  
Maglev Vehicle ◽  
Suspension Control ◽  
Diagnosis Method ◽  
Real Value ◽  
Control System Model

Firstly, build the suspension-control-system model under the condition of elastic guideway, and design the controller. Secondly, design the Kalman forecaster based on model, and diagnose the fault by comparing forecasted value with real value. Finally, verify the effectiveness of this fault diagnosis method for suspension signal by simulation.

An Analysis of Water Management for a PEM Fuel Cell System in Automotive Drive Cycles

2003 ◽  
Author(s):  
Kristina Haraldsson ◽  
Tony Markel ◽  
Keith Wipke
Keyword(s):  
Water Management ◽  
Fuel Cell ◽  
Water Balance ◽  
Power Output ◽  
Pem Fuel Cell ◽  
Cell System ◽  
System Model ◽  
Fuel Cell System ◽  
Vehicle System ◽  
Aggressive Drive

Low-temperature operation of a Proton Exchange Membrane (PEM) fuel cell system requires humidification of the membrane. The amount of water produced electrochemically within the fuel cell system is directly related to the system power output. In a vehicular application where the power output may vary substantially over time, it is critical that water management be addressed in the fuel cell and vehicle system design. This paper introduces the integration of a detailed fuel cell system model within a hybrid electric vehicle system model. The newly integrated models provide the capability to better understand the impacts of a variety of fuel cell and vehicle design parameters on overall system performance. Ultimately, coupling these models leads to system optimization and increased vehicle efficiency. This paper presents the initial results of a parametric study to quantify the impacts of condenser size and cathode inlet relative humidity on system water balance under realistic drive cycles in a fuel cell hybrid electric sport utility vehicle. The vehicle simulations included operation under both hot and ambient start conditions. The study results demonstrate that ambient start or aggressive drive cycles require larger condensers or water reservoirs to maintain a neutral water balance than either hot start or less aggressive drive cycles.

Dynamic Analysis of a Towed Underwater Vehicle System: Model Validation

2004 ◽  
Author(s):  
Gry Karin Haugen ◽  
Mads Grahl-Madsen
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Model ◽  
Dynamic Behaviour ◽  
Equations Of Motion ◽  
Underwater Vehicle ◽  
Integrated System ◽  
System Model ◽  
Cable Model ◽  
Vehicle System ◽  
Successful Design

An integrated system consisting of two towed sub-sea vehicles and a free-floating probe is being developed to perform mapping and quantitative estimations for fish and plankton. A thorough understanding of the dynamic behaviour of the towed vehicle system is essential for a successful design, and a dynamic model that can accurately describe the vehicle behaviour under the influence of a wide variation of conditions, is necessary. This paper discusses two different approaches for the dynamic analysis of a towed vehicle system. Analyses are performed using the commercial available simulation program MOSES. Further the 2D equations of motion for the towed vehicle are developed and solved in Matlab using a simple cable model.

scholarly journals Mathematical model of pantograph cooperation with two degrees of freedom with a catenary system

2019 ◽  
Vol 294 ◽  
pp. 05005
Author(s):  
Marek Kaniewski ◽  
Michał Cichoński
Keyword(s):  
Mathematical Model ◽  
Discrete Model ◽  
Degrees Of Freedom ◽  
Variable Stiffness ◽  
System Model ◽  
Dynamic State ◽  
Rolling Stock ◽  
Two Degrees Of Freedom ◽  
Technical Specifications ◽  
Catenary System

The authors present a method of modeling pantograph cooperation with a catenary system by means of a computer program based on a pantograph discrete model with two degrees of freedom and a catenary system model as a focused mass that in the dynamic state has variable stiffness along the span. After performing the appropriate tests, the validation was carried out according to the proposed method in the PN EN 50318:2019-02 standard required in the Technical Specifications for the interoperability of the subsystem “Energy” and “Rolling stock -locomotives and passenger rolling stock” of the trans-European rail system in Europe.

The Behaviour of Railway Wheelsets and Track at High Frequencies of Excitation

1982 ◽  
Vol 24 (2) ◽  
pp. 103-111 ◽  
Author(s):  
S. L. Grassie ◽  
R. W. Gregory ◽  
K. L. Johnson
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Contact Force ◽  
Analytical Methods ◽  
Dynamical Response ◽  
Frequency Range ◽  
High Frequencies ◽  
Good Agreement

The dynamical response in the frequency range 50–1500 Hz is investigated of a railway wheelset resting on the track and excited vertically, laterally and longitudinally at a point of contact. A mathematical model of a railway wheelset is developed which comprises a few simple components to which analytical methods can be applied. Good agreement is obtained between experimental data and calculations made using this model. For a given sinusoidal displacement imposed between wheel and rail, the contact force is in general greatest longitudinally and least laterally.

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