Influences of the Front Wheel Steering Angle on Vehicle Handling and Stability

2012 ◽  
Vol 195-196 ◽  
pp. 41-46
Author(s):  
Chuan Bo Ren ◽  
Cui Cui Zhang ◽  
Lin Liu
Keyword(s):  
Differential Equation ◽  
Degrees Of Freedom ◽  
Front Wheel ◽  
Steady State Response ◽  
Vehicle Model ◽  
Steering Angle ◽  
Vehicle Handling ◽  
Two Degrees Of Freedom ◽  
Amplitude Frequency Characteristic ◽  
State Response

In this paper, motion differential equation of the two degrees of freedom (2-DOF) vehicle is established based on the linear two degrees of freedom vehicle model and is derived without simplifying the front wheel steering angle (FWSA), then we analyze the vehicle's steady-state response , transient response and the amplitude-frequency characteristic of yaw velocity under different FWSA with the help of the matlab software and finally compare the results with the simplified ones to determine how the FWSA influences the level of the vehicle handling and stability (VHS). The results show that: while the FWSA is small, it has a less influence on vehicle handling and stability, the FWSA is large, it has a greater influence on vehicle handling and stability.

Rollover stability of a vehicle during critical driving manoeuvres

2007 ◽  
Vol 221 (9) ◽  
pp. 1041-1049 ◽  
Author(s):  
Z L Jin ◽  
J S Weng ◽  
H Y Hu
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Front Wheel ◽  
Front Axle ◽  
Stability Factor ◽  
Vehicle Speed ◽  
Vehicle Model ◽  
Steering Angle ◽  
Vehicle Rollover ◽  
The Stability

In this paper, a linear vehicle model with three degrees of freedom is established to study the stability of vehicle rollover due to critical driving manoeuvres. From the linear vehicle model, the stability conditions are determined on the basis of the Routh-Hurwitz criterion, and a so-called dynamic stability factor is defined to reveal the effects of system parameters on the stability of vehicle rollover. In order to demonstrate the theoretical results, two numerical examples are given for the rollover of a sport utility vehicle in cornering and lane-change manoeuvres at a high speed and large steering angle. The stability regions are shown with respect to the vehicle speed and the vehicle parameters, such as the longitudinal distance from the centre of gravity to the front axle, and the steering angle of the front wheel.

Periodic Steady State Response and Fatigue Analysis of a Nonlinear City Bus Model

2009 ◽  
Author(s):  
George Valsamos ◽  
Christos Theodosiou ◽  
Sotirios Natsiavas
Keyword(s):  
Steady State ◽  
Degrees Of Freedom ◽  
Nonlinear Models ◽  
Equations Of Motion ◽  
High Stress ◽  
Direct Determination ◽  
Accurate Information ◽  
Steady State Response ◽  
State Response ◽  
Periodic Steady State

Dynamic response related to fatigue prediction of an urban bus is investigated. First, a quite complete model subjected to road excitation is employed in order to extract sufficiently reliable and accurate information in a fast way. The bus model is set up by applying the finite element method, resulting to an excessive number of degrees of freedom. In addition, the bus suspension units involve nonlinear characterstics. A step towards alleviating this difficulty is the application of an appropriate coordinate transformation, causing a drastic reduction in the dimension of the final set of the equations of motion. This allows the application of a systematic numerical methodology leading to direct determination of periodic steady state response of nonlinear models subjected to periodic excitation. Next, typical results were obtained for excitation resulting from selected urban road profiles. These profiles have either a known form or known statistical properties, expressed by an appropriate spatial power spectral density function. In all cases examined, the emphasis was put on investigating ride response. The main attention was focused on identifying areas of the bus suspension and frame subsystems where high stress levels are developed. This information is based on the idea of a nonlinear transfer function and provides the basis for applying suitable criteria in order to perform analyses leading to prediction of fatigue failure.

scholarly journals Nonlinear Models for Transverse Forced Vibration of Axially Moving Viscoelastic Beams

2011 ◽  
Vol 18 (1-2) ◽  
pp. 281-287 ◽  
Author(s):  
Hu Ding ◽  
Li-Qun Chen
Keyword(s):  
Differential Equation ◽  
Partial Differential Equation ◽  
Steady State ◽  
Transverse Vibration ◽  
Nonlinear Models ◽  
Transverse Motion ◽  
Steady State Response ◽  
Partial Differential ◽  
State Response ◽  
Axially Moving

Nonlinear models of transverse vibration of axially moving viscoelastic beams subjected external transverse loads via steady-state periodical response are numerically investigated. An integro-partial-differential equation and a partial-differential equation of transverse motion can be derived respectively from a model of the coupled planar vibration for an axially moving beam. The finite difference scheme is developed to calculate steady-state response for the model of coupled planar and the two models of transverse motion under the simple support boundary. Numerical results indicate that the amplitude of the steady-state response for the model of coupled vibration and two models of transverse vibration predict qualitatively the same tendencies with the changing parameters and the integro-partial-differential equation gives results more closely to the coupled planar vibration.

Sensitivity Analysis of Vehicle Parameters on Dynamic Stability and Vehicle Handling Performance

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
M.M.M. Salem ◽  
Mina. M Ibrahim ◽  
M.A. Mourad ◽  
K.A. Abd El-Gwwad
Keyword(s):  
Dynamic Stability ◽  
Degrees Of Freedom ◽  
Front Wheel ◽  
Lateral Acceleration ◽  
Vehicle Speed ◽  
Vehicle Dynamic ◽  
Vehicle Handling ◽  
Bicycle Model ◽  
State Region ◽  
The Mathematical Model

In this paper, a linear two degrees of freedom linear bicycle model is proposed to investigate the vehicle handling criterion. The study is based on simulation developed using MATLAB / Simulink to predict the vehicle dynamic stability. Steering angle is given as an input to the mathematical model for various vehicular manoeuvres. This model is validated using a step input which is adjusted to give 0.3g lateral acceleration. The system model is simulated under a typical front wheel steering to examine the highway vehicle prediction output within its manoeuvre. This input is also adjusted to keep lateral acceleration value in steady state region. It is found that changing the vehicle center of gravity (CG) position, vehicle mass, tire cornering stiffness and vehicle speed all have a significant influence on the vehicle dynamic stability.

Application of Error Analysis Method in the Complex Vehicle Model

2012 ◽  
Vol 591-593 ◽  
pp. 584-587
Author(s):  
Shui Rong Liao ◽  
Tao Yang
Keyword(s):  
Error Analysis ◽  
Degrees Of Freedom ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Model Parameters ◽  
Vehicle Model ◽  
Two Degrees Of Freedom ◽  
Input Amplitude ◽  
Sinusoidal Input ◽  
Set Up

A two degree of freedom input vehicle model is set up. Based on driver modeling analytical method of error analysis, step signal is taken as the input of steering angle to complex vehicle model based on CarSim, vehicle lateral acceleration is taken as as output. Meanwhile, the same steering wheel angle is taken as input as equivalent two degrees of freedom vehicle model, vehicle model parameters are optimized based on the minimum objective function. The results show that, in the same kind of speed, for steering wheel angle step input and sinusoidal input , when the input amplitude increases, the equivalent accuracy of the complex vehicle model and two degrees of freedom vehicle model will be reduced.

scholarly journals Principal Parametric Resonance of Axially Accelerating Viscoelastic Beams: Multi-Scale Analysis and Differential Quadrature Verification

2012 ◽  
Vol 19 (4) ◽  
pp. 527-543 ◽  
Author(s):  
Li-Qun Chen ◽  
Hu Ding ◽  
C.W. Lim
Keyword(s):  
Differential Equation ◽  
Partial Differential Equation ◽  
Steady State ◽  
Multiple Scales ◽  
Method Of Multiple Scales ◽  
Steady State Response ◽  
Governing Equations ◽  
State Response ◽  
Non Linear ◽  
Axial Speed

Transverse non-linear vibration is investigated in principal parametric resonance of an axially accelerating viscoelastic beam. The axial speed is characterized as a simple harmonic variation about a constant mean speed. The material time derivative is used in the viscoelastic constitutive relation. The transverse motion can be governed by a non-linear partial-differential equation or a non-linear integro-partial-differential equation. The method of multiple scales is applied to the governing equations to determine steady-state responses. It is confirmed that the mode uninvolved in the resonance has no effect on the steady-state response. The differential quadrature schemes are developed to verify results via the method of multiple scales. It is demonstrated that the straight equilibrium configuration becomes unstable and a stable steady-state emerges when the axial speed variation frequency is close to twice any linear natural frequency. The results derived for two governing equations are qualitatively the same, but quantitatively different. Numerical simulations are presented to examine the effects of the mean speed and the variation of the amplitude of the axial speed, the dynamic viscosity, the non-linear coefficients, and the boundary constraint stiffness on the instability interval and the steady-state response amplitude.

scholarly journals Analysis of Vehicle Steering and Driving Bifurcation Characteristics

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Xianbin Wang ◽  
Shuming Shi
Keyword(s):  
Degrees Of Freedom ◽  
Autonomous Vehicle ◽  
Lateral Force ◽  
Front Wheel ◽  
State Variables ◽  
Vehicle Model ◽  
Obvious Effect ◽  
Driving Mode ◽  
Lyapunov Index ◽  
Driving Torque

The typical method of vehicle steering bifurcation analysis is based on the nonlinear autonomous vehicle model deriving from the classic two degrees of freedom (2DOF) linear vehicle model. This method usually neglects the driving effect on steering bifurcation characteristics. However, in the steering and driving combined conditions, the tyre under different driving conditions can provide different lateral force. The steering bifurcation mechanism without the driving effect is not able to fully reveal the vehicle steering and driving bifurcation characteristics. Aiming at the aforementioned problem, this paper analyzed the vehicle steering and driving bifurcation characteristics with the consideration of driving effect. Based on the 5DOF vehicle system dynamics model with the consideration of driving effect, the 7DOF autonomous system model was established. The vehicle steering and driving bifurcation dynamic characteristics were analyzed with different driving mode and driving torque. Taking the front-wheel-drive system as an example, the dynamic evolution process of steering and driving bifurcation was analyzed by phase space, system state variables, power spectral density, and Lyapunov index. The numerical recognition results of chaos were also provided. The research results show that the driving mode and driving torque have the obvious effect on steering and driving bifurcation characteristics.

Stability of the Vibrations of a Parameter-Excited System

1982 ◽  
Vol 49 (4) ◽  
pp. 920-921
Author(s):  
M. Gu¨rgo¨ze
Keyword(s):  
Differential Equation ◽  
Degrees Of Freedom ◽  
Instability Region ◽  
Horizontal Plate ◽  
Two Degrees Of Freedom ◽  
Excited System ◽  
The Subject ◽  
Excitation Frequencies ◽  
The Stability ◽  
Special Parameter

The subject of this Brief Note is to introduce a special parameter-excited system with two degrees of freedom, which has its principal instability region at ω ≈ ω0 instead at ω ≈ 2ω0. It consists of a horizontal plate with a fixed pin and a slotted rigid bar on it, in which the bar can rotate and translate with respect to the plate. The stability of its vibrations is investigated for the case in which the plate is harmonicaly excited in its own plane. Starting with the Mathieu differential equation, which governs the rotational vibrations, it is possible to predict the excitation frequencies, which must be avoided, to ensure the stability.

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