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.

Vehicle coupled bifurcation analysis of steering angle and driving torque

2021 ◽  
pp. 095440702098540
Author(s):  
Xianbin Wang ◽  
Shuming Shi
Keyword(s):  
Bifurcation Analysis ◽  
Hybrid Method ◽  
Vehicle Dynamics ◽  
Front Wheel ◽  
Steering Angle ◽  
Driving Mode ◽  
Vehicle System ◽  
Autonomous Equation ◽  
Real Coded Genetic Algorithm ◽  
Driving Torque

The mechanism of vehicle dynamics steering bifurcation has almost been confirmed. But the present steering bifurcation mechanism cannot explain the bifurcation phenomena caused by the driving torque. As a result, the vehicle coupled bifurcation analysis of the steering angle and driving torque has not been studied. Based on the five degrees of freedom (5DOF) vehicle system dynamics model with driving torque involved, the vehicle dynamics equilibriums under different driving torque and driving mode were searched by a hybrid method in this paper. The hybrid method combined the real-coded Genetic Algorithm with Quasi-Newton gradient method. According to the definition of static bifurcation of nonlinear systems, the equilibrium bifurcation of 5DOF vehicle system was confirmed. Then, the 5DOF vehicle system model was transformed into autonomous equation with the front wheel steering angle as intermediate variable. From the two aspects of constant steering angle amplitude and constant driving torque, the bifurcation diagrams of different driving mode were calculated. The vehicle coupled bifurcation characteristics of steering angle and driving torque were analyzed. The results show that the values of the driving torque will directly affect the bifurcation characteristics of vehicle dynamics system. The coupled feature of the front wheel steering angle and driving torque effect on vehicle bifurcation is obvious.

Bifurcation analysis of vehicle shimmy system exposed to road roughness excitation

2021 ◽  
pp. 107754632098779
Author(s):  
Heng Wei ◽  
Jian-Wei Lu ◽  
Sheng-Yong Ye ◽  
Hang-Yu Lu
Keyword(s):  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Averaging Method ◽  
Lagrange Equation ◽  
Response Characteristic ◽  
Lateral Force ◽  
Front Wheel ◽  
The Road ◽  
Road Roughness ◽  
The Stability

The vertical load of the tire has a significant influence on the lateral force, so the influence of the dynamic load on vehicle shimmy should be taken into account. Based on the dynamic model of a quarter vehicle, a three-degrees-of-freedom dynamic model of the shimmy system with consideration of the road roughness excitation is established by applying the second Lagrange equation. The response characteristic of the system is investigated by the numerical simulations. Moreover, the complexification-averaging method is used to obtain the analytical expression of the shimmy angle of the front wheel, and then, the stability of periodic solutions of the system is evaluated based on the bifurcation theory. Finally, the saddle-node bifurcation and Hopf bifurcation of the shimmy system are studied. The influence of the system parameters on the bifurcation characteristic of the system is also investigated, and the results obtained by using the complexification-averaging method are compared with the numerical examples.

A New Methodology to Get Reliable Input Data for Handling Simulations

1999 ◽  
Vol 27 (3) ◽  
pp. 176-187 ◽  
Author(s):  
F. Mancosu ◽  
D. Speziari ◽  
M. Ceresa ◽  
P. Sbarbati
Keyword(s):  
Degrees Of Freedom ◽  
Transient Behavior ◽  
Parameters Estimation ◽  
Identification Algorithm ◽  
State Variables ◽  
Vehicle Model ◽  
Magic Formula ◽  
Experimental Activity ◽  
Tire Forces ◽  
Good Agreement

Abstract This paper presents a methodology to obtain tire and vehicle parameters suitable for handling simulations, describing the experimental activity needed, a vehicle model, and an appropriate identification algorithm. The vehicle model has four degrees of freedom and takes into account roll movements, load transfers among the four tires, and lateral tire forces, described by the Magic Formula with transient behavior. The resulting system has 10 state variables. A vehicle was equipped with standard sensors used by vehicle manufacturers in handling maneuvers and wheel vector transducers that measure the displacements and angles of the four hubs with respect to the chassis. Handling tests were performed, and some of the results were used to identify the tire Magic Formula coefficients and part of the vehicle parameters, using an Extended Kalman filter. The remaining tests were used for the validation: the results showed good agreement between simulations and measurements, confirming the validity of the model and the accuracy of the parameters' estimation.

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.

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.

Regular perturbations to the motion of a three-wheeled mobile robot with the front-wheel drive under restricted state variables*

2020 ◽  
Author(s):  
Roman Chertovskih ◽  
Anna Daryina ◽  
Askhat Diveev ◽  
Dmitry Karamzin ◽  
Fernando L. Pereira ◽  
...  
Keyword(s):  
Mobile Robot ◽  
Front Wheel ◽  
Wheeled Mobile Robot ◽  
State Variables ◽  
Wheel Drive

scholarly journals Modelling of the system “driver - automation - autonomous vehicle - road”

2020 ◽  
Vol 10 (1) ◽  
pp. 175-182 ◽  
Author(s):  
Grzegorz Koralewski
Keyword(s):  
Autonomous Vehicles ◽  
Combustion Engine ◽  
Autonomous Vehicle ◽  
Application Software ◽  
Motion Simulation ◽  
Gear Shift ◽  
Shift Control ◽  
Driving Torque ◽  
Physical Quantities ◽  
Motion Quality

AbstractThe work presents a simulation model of a “driver–automation–autonomous vehicles–road” system which is the basis for synthesis of automatic gear shift control system. The mathematical description makes use of physical quantities which characterise driving torque transformation from the combustion engine to the car driven wheels. The basic components of the model are algorithms for the driver’s action logic in controlling motion velocity, logic of gear shift control functioning regarding direction and moment of switching, for determining right-hand side of differential equations and for motion quality indicators. The model is realised in a form of an application software package, comprising sub-programmes for input data, for computerised motion simulation of cars with mechanical and hydro-mechanical – automatically controlled – transmission systems and for models of characteristic car routes.

A novel path tracking approach considering safety of the intended functionality for autonomous vehicles

2021 ◽  
pp. 095440702110205
Author(s):  
Huiran Wang ◽  
Qidong Wang ◽  
Wuwei Chen ◽  
Linfeng Zhao ◽  
Dongkui Tan
Keyword(s):  
Autonomous Vehicles ◽  
Autonomous Vehicle ◽  
Coordinated Control ◽  
Steering System ◽  
Front Wheel ◽  
Path Tracking ◽  
Hierarchical Architecture ◽  
Automatic Steering ◽  
The Stability ◽  
Control Layer

To reduce the adverse effect of the functional insufficiency of the steering system on the accuracy of path tracking, a path tracking approach considering safety of the intended functionality is proposed by coordinating automatic steering and differential braking in this paper. The proposed method adopts a hierarchical architecture consisting of a coordinated control layer and an execution control layer. In coordinated control layer, an extension controller considering functional insufficiency of the steering system, tire force characteristics and vehicle driving stability is proposed to determine the weight coefficients of automatic steering and the differential braking, and a model predictive controller is designed to calculate the desired front wheel angle and additional yaw moment. In execution control layer, a H∞ steering angle controller considering external disturbances and parameter uncertainty is designed to track desired front wheel angle, and a braking force distribution module is used to determine the wheel cylinder pressure of the controlled wheels. Both simulation and experiment results show that the proposed method can overcome the functional insufficiency of the steering system and improve the accuracy of path tracking while maintaining the stability of the autonomous vehicle.

Modeling of nonlinear torsional vibration of the automotive powertrain

2016 ◽  
Vol 24 (9) ◽  
pp. 1774-1786 ◽  
Author(s):  
Sérgio J Idehara ◽  
Fernando L Flach ◽  
Douglas Lemes
Keyword(s):  
Natural Frequency ◽  
Torsional Vibration ◽  
Degrees Of Freedom ◽  
Front Wheel ◽  
Torsional Stiffness ◽  
Bench Test ◽  
Passenger Car ◽  
Engine Torque ◽  
Friction Moment ◽  
Wheel Drive

A vibration model of the powertrain can be used to predict its dynamic behavior when excited by fluctuations in the engine torque and speed. The torsional vibration resulting from torque and speed fluctuations increases the rattle noise in the gearbox and it should be controlled or minimized in order to gain acceptance by clients and manufactures. The fact that the proprieties of the torsional damper integrated into the clutch disc alter the dynamic characteristic of the system is important in the automotive industry for design purposes. In this study, bench test results for the characteristics of a torsional damper for a clutch system (torsional stiffness and friction moment) and powertrain torsional vibration measurements taken in a passenger car were used to verify and calibrate the model. The adjusted model estimates the driveline natural frequency and the time response vibration. The analysis uses order tracking signal processing to isolate the response from the engine excitation (second-order). It is shown that a decrease in the stiffness of the clutch disc torsional damper lowers the natural frequency and an increase in the friction moment reduces the peak amplitude of the gearbox torsional vibration. The formulation and model adjustment showed that a nonlinear model with three degrees of freedom can represent satisfactorily the powertrain dynamics of a front-wheel drive passenger car.

Trajectory Tracking of Underactuated Multibody Systems

2011 ◽  
Author(s):  
Stefan Reichl ◽  
Wolfgang Steiner
Keyword(s):  
Trajectory Tracking ◽  
Multibody Systems ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Feedforward Control ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Differential Algebraic Equations ◽  
State Variables ◽  
Algebraic Equations

This work presents three different approaches in inverse dynamics for the solution of trajectory tracking problems in underactuated multibody systems. Such systems are characterized by less control inputs than degrees of freedom. The first approach uses an extension of the equations of motion by geometric and control constraints. This results in index-five differential-algebraic equations. A projection method is used to reduce the systems index and the resulting equations are solved numerically. The second method is a flatness-based feedforward control design. Input and state variables can be parameterized by the flat outputs and their time derivatives up to a certain order. The third approach uses an optimal control algorithm which is based on the minimization of a cost functional including system outputs and desired trajectory. It has to be distinguished between direct and indirect methods. These specific methods are applied to an underactuated planar crane and a three-dimensional rotary crane.

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