Modeling and Analysis of Active Differential Dynamics

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Joško Deur ◽  
Vladimir Ivanović ◽  
Matthew Hancock ◽  
Francis Assadian
Keyword(s):  
Model Complexity ◽  
Traction Control ◽  
Modeling And Analysis ◽  
Response Characteristics ◽  
Graph Modeling ◽  
Torque Vectoring ◽  
Bond Graph Modeling ◽  
Overall Performance ◽  
Vehicle Dynamics Control ◽  
Different Levels

Active differentials are used to improve the overall performance of traction control and vehicle dynamics control systems. This paper presents the development of a unified mathematical model of active differential dynamics using the bond graph modeling technique. The study includes active limited slip differential and various common types of torque vectoring differentials. Different levels of model complexity are considered, starting from a second-order model with lumped input and output inertia toward higher-order models including the gear inertia and half-shaft compliance. The model is used for a theoretical analysis of drivability and time response characteristics of the active differential dynamics. The analysis is illustrated by simulation results.

Modeling of Active Differential Dynamics

2008 ◽  
Author(s):  
Josˇko Deur ◽  
Matthew Hancock ◽  
Francis Assadian
Keyword(s):  
Model Simulation ◽  
Model Complexity ◽  
Order Model ◽  
Graph Modeling ◽  
Torque Vectoring ◽  
Bond Graph Modeling ◽  
Overall Performance ◽  
Vehicle Dynamics Control ◽  
Typical Model ◽  
Different Levels

Active differentials are increasingly being used in high-end vehicles in order to improve the overall performance of vehicle dynamics control systems. The active differentials can be divided into active limited slip differentials and torque vectoring differentials. This paper presents the development of a generalized mathematical model of active differential dynamics using the bond graph modeling technique. Different levels of model complexity are considered, starting from a second-order model with lumped input and output inertia towards high order models including the gear inertia and halfshaft compliance. The paper also presents typical model simulation results and their comparative analysis with respect to drivability and time response features.

Bond Graph Modeling and Analysis of Active Differential Kinematics

2008 ◽  
Author(s):  
Josˇko Deur ◽  
Matthew Hancock ◽  
Francis Assadian
Keyword(s):  
Comparative Analysis ◽  
Bond Graph ◽  
Modeling And Analysis ◽  
Graph Method ◽  
Operating Modes ◽  
Graph Modeling ◽  
Torque Vectoring ◽  
Bond Graph Modeling ◽  
And Performance

This paper describes the kinematic structures of Active Limited Slip Differential (ALSD) and different concepts of Torque Vectoring Differentials (TVD) (superposition clutch concept, stationary clutch concept, and 4WD concept). The bond graph method is used to derive the models of ALSD/TVD kinematics. Based on the developed models, a comparative analysis of active differential operating modes and performance is conducted.

Bond Graph Modeling and Analysis of HEV System Based on Ravigneaux Planetary Mechanism

2013 ◽  
Vol 724-725 ◽  
pp. 1402-1408
Author(s):  
Li He Xi ◽  
Hong Wei Chen ◽  
Xin Zhang
Keyword(s):  
Bond Graph ◽  
Structural Form ◽  
Graph Models ◽  
Modeling And Analysis ◽  
Electric System ◽  
Operating Modes ◽  
Graph Modeling ◽  
Time Requirements ◽  
Bond Graph Modeling ◽  
Planetary Mechanism

The bond graph method is used to analyse and model dynamics of hybrid electric system based on Ravigneaux Planetary Mechanism. Bond graph models are built in different structural form, general equations of torque and speed are derived, and operating modes achieved in different structural form are in consideration. At the same time, requirements of control system in different operating modes are illustrated and analysed, which help lay the foundations for modeling and simulation of HEV system based on Ravigneaux Planetary Mechanism.

Modeling and Analysis of Automatic Transmission Engagement Dynamics-Linear Case

2005 ◽  
Vol 128 (2) ◽  
pp. 263-277 ◽  
Author(s):  
Joško Deur ◽  
Jahan Asgari ◽  
Davor Hrovat ◽  
Petar Kovač
Keyword(s):  
Computer Simulations ◽  
Automatic Transmission ◽  
Planetary Gear ◽  
Torque Converter ◽  
Bond Graph ◽  
Friction Model ◽  
Linear Case ◽  
Modeling And Analysis ◽  
Graph Modeling ◽  
Bond Graph Modeling

A control-oriented model of a typical four-speed automatic transmission is developed by using the bond graph modeling method. The planetary gear set model utilizes the Karnopp friction model for hydraulic and one-way clutches, in order to provide a favorable computing efficiency. The full gear set model is reduced for various phases of the park/reverse and park/drive engagements. The reduced gear set models and linearized torque converter model are used as a basis for an algebraic analysis of the engagement dynamics. The analysis is originally conducted for the basic case of fully applied brake, and it is then extended by an analysis of the influence of wheel dynamics in the brake-off case. The analysis results are verified by computer simulations and experiments.

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.

A Control-Oriented Model of Hydrostatic Transmission With Application on Torque Vectoring Differential Modeling

2008 ◽  
Author(s):  
Josˇko Deur ◽  
Vladimir Ivanovic´ ◽  
Josˇko Petric´ ◽  
Matthew Hancock ◽  
Francis Assadian
Keyword(s):  
Operating Conditions ◽  
State Variables ◽  
Motor Speed ◽  
Modeling And Analysis ◽  
Pump Speed ◽  
Hydrostatic Transmission ◽  
Wide Range ◽  
Torque Vectoring ◽  
Flow Loss ◽  
Bond Graph Modeling

The paper presents a control-oriented model of a closed circuit hydrostatic transmission. The model includes the pump speed, motor speed, and pressure difference state variables, and nonlinear static maps for the flow loss resistance and pump and motor torque losses. The model maps are obtained by experimental identification conducted on a hydrostatic transmission setup. The model is validated against the experimental data for a wide range of operating conditions. The validated model is used for bond graph modeling and analysis of a hydrostatic transmission-based torque vectoring differential. The torque vectoring features are illustrated by computer simulation.

On the Frequency Response of a Spinning Disk With Large Deformations

2010 ◽  
Author(s):  
Ramin M. H. Khorasany ◽  
Stanley G. Hutton
Keyword(s):  
Frequency Response ◽  
Plate Theory ◽  
Equations Of Motion ◽  
Rotating Disk ◽  
Nonlinear Frequency ◽  
Response Characteristics ◽  
Geometrical Nonlinear ◽  
Oscillation Frequencies ◽  
Multi Mode ◽  
Different Levels

In this paper, the effect of geometrical nonlinear terms, caused by a space fixed point force, on the frequencies of oscillations of a rotating disk with clamped-free boundary conditions is investigated. The nonlinear geometrical equations of motion are based on Von Karman plate theory. Using the eigenfunctions of a stationary disk as approximating functions in Galerkin’s method, the equations of motion are transformed into a set of coupled nonlinear Ordinary Differential Equations (ODEs). These equations are then used to find the equilibrium positions of the disk at different discrete blade speeds. At any given speed, the governing equations are linearized about the equilibrium solution of the disk under the application of a space fixed external force. These linearized equations are then used to find the oscillation frequencies of the disk considering the effect of large deformation. Using multi mode approximation and different levels of nonlinearity, the frequency response of the disk considering the effect of geometrical nonlinear terms are studied. It is found that at the linear critical speed, the nonlinear frequency of the corresponding mode is not zero. Results are presented that illustrate the effect of the magnitude of disk displacement upon the frequency response characteristics. It is also found that for each mode, including the effect of the geometrical nonlinear terms due to the applied load causes a separation in the frequency responses of its backward and forward traveling waves when the disk is stationary. This effect is similar to the effect of a space fixed constraint in the linear problem. In order to verify the numerical results, experiments are conducted and the results are presented.

scholarly journals Comparative investigations of nonlinear and linear observers for a highly manoeuvrable target in sliding mode guidance

2017 ◽  
Vol 65 (2) ◽  
pp. 233-245
Author(s):  
Y. Wang ◽  
M. Sun ◽  
S. Du ◽  
Z. Chen
Keyword(s):  
Sliding Mode ◽  
Guidance System ◽  
Key Factors ◽  
Factors Affecting ◽  
First Order ◽  
Guidance Law ◽  
Linear Observer ◽  
Overall Performance ◽  
Twisting Algorithm ◽  
Different Levels

Abstract Target manoeuvre is one of the key factors affecting guidance accuracy. To intercept highly maneuverable targets, a second-order sliding-mode guidance law, which is based on the super-twisting algorithm, is designed without depending on any information about the target motion. In the designed guidance system, the target estimator plays an essential role. Besides the existing higher-order sliding-mode observer (HOSMO), a first-order linear observer (FOLO) is also proposed to estimate the target manoeuvre, and this is the major contribution of this paper. The closed-loop guidance system can be guaranteed to be uniformly ultimately bounded (UUB) in the presence of the FOLO. The comparative simulations are carried out to investigate the overall performance resulting from these two categories of observers. The results show that the guidance law with the proposed linear observer can achieve better comprehensive criteria for the amplitude of normalised acceleration and elevator deflection requirements. The reasons for the different levels of performance of these two observer-based methods are thoroughly investigated.

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