Active camber system for lateral stability improvement of urban vehicles

2019 ◽  
Vol 233 (14) ◽  
pp. 3824-3838 ◽  
Author(s):  
Mansour Ataei ◽  
Chen Tang ◽  
Amir Khajepour ◽  
Soo Jeon
Keyword(s):  
Vehicle Dynamics ◽  
Vehicle Stability ◽  
Lateral Stability ◽  
Tire Model ◽  
Vehicle Model ◽  
Sideslip Angle ◽  
Friction Forces ◽  
Additional Degree ◽  
Tire Force ◽  
Active Front Steering

A suspension system with the capability of cambering has an additional degree of freedom for changing camber angle to increase the maximum lateral tire force. This study investigates the effects of cambering on overall vehicle stability with emphasis on applications to urban vehicles. A full vehicle model with a reliable tire model including camber effects is employed to investigate the vehicle dynamics behavior under cambering. Besides, a linearized vehicle model is used to analytically study the effects of camber lateral forces on vehicle dynamics. Vehicle behavior for different configurations of camber angles in front and rear wheels is studied and compared. Then, an active camber system is suggested for improvement of vehicle lateral stability. Specifically, performances of active front camber, active rear camber, and their combination are investigated. The results show that a proper strategy for camber control can improve both yaw rate and sideslip angle, simultaneously. Finally, the active front camber system is compared with the well-known active front steering. It is shown that, utilizing more friction forces at the limits, active front camber is more effective in improving maneuverability and lateral stability than active front steering.

Construction of a Rational Tire Model for High Fidelity Vehicle Dynamics Simulation Under Extreme Driving and Environmental Conditions

2010 ◽  
Author(s):  
S. C¸ag˘lar Bas¸lamıs¸lı ◽  
Selim Solmaz
Keyword(s):  
Vehicle Dynamics ◽  
Dynamics Simulation ◽  
High Fidelity ◽  
Tire Model ◽  
Dynamics Model ◽  
Vehicle Model ◽  
Prospective Design ◽  
Magic Formula ◽  
Rational Models ◽  
Simulation Results

In this paper, a control oriented rational tire model is developed and incorporated in a two-track vehicle dynamics model for the prospective design of vehicle dynamics controllers. The tire model proposed in this paper is an enhancement over previous rational models which have taken into account only the peaking and saturation behavior disregarding all other force generation characteristics. Simulation results have been conducted to compare the dynamics of a vehicle model equipped with a Magic Formula tire model, a rational tire model available in the literature and the present rational tire model. It has been observed that the proposed tire model results in vehicle responses that closely follow those obtained with the Magic Formula even for extreme driving scenarios conducted on roads with low adhesion coefficient.

scholarly journals Conflict and Sensitivity Analysis of Vehicular Stability Using a Two-State Linear Bicycle Model

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Mohamed A. Hassan ◽  
Mohamed A. A. Abdelkareem ◽  
Gangfeng Tan ◽  
M. M. Moheyeldein
Keyword(s):  
Critical Role ◽  
Lateral Acceleration ◽  
Vehicle Stability ◽  
Vehicle Speed ◽  
Sideslip Angle ◽  
Tire Force ◽  
Operation Conditions ◽  
Bicycle Model ◽  
Tire Stiffness ◽  
Longitudinal Position

Vehicle parameters and operation conditions play a critical role in vehicular handling and stability. This study aimed to evaluate vehicle stability based on cornering tire stiffness integrated with vehicle parameters. A passenger vehicle is considered in which a two-state linear bicycle model is developed in the Matlab/Simulink. The effect of the vehicle parameters on lateral vehicle stability has been investigated and analyzed. The investigated parameters included CG longitudinal position, wheelbase, and tire cornering stiffness. Furthermore, the effects of load variation and vehicle speed were addressed. Based on a Fishhook steering maneuver, the lateral stability criteria represented in lateral acceleration, yaw rate, vehicle sideslip angle, tire sideslip angles, and the lateral tire force were analyzed. The results demonstrated that the parameters that affect the lateral vehicle stability the most are the cornering stiffness coefficient and the CG longitudinal location. The findings also indicated a positive correlation between vehicle properties and lateral handling and stability.

scholarly journals An Advanced Shell Theory Based Tire Model

2005 ◽  
Vol 33 (4) ◽  
pp. 227-238 ◽  
Author(s):  
D. Bozdog ◽  
W. W. Olson
Keyword(s):  
Vehicle Dynamics ◽  
Shell Theory ◽  
Finite Difference Methods ◽  
Integrated Approach ◽  
Tire Model ◽  
Element Analysis ◽  
Friction Forces ◽  
Dynamic Analyses ◽  
Tire Models ◽  
Elastic Substance

Abstract The objective of this paper is to investigate a class of general tire models that provides results suitable for usage in vehicle dynamics. Tire models currently used for vehicle dynamic analyses are overly simplistic (springs, a spring and damper combination or semi-elastic substance) or based on curve fits of experimental data. In contrast, the tire models used by major tire companies are extremely complex with solutions possible only by finite element analysis. Between these two extremes exists the potential for an elasticity based shell theory tire model. Micro-mechanics and composite laminate theories provide an integrated approach to the macroscopic behavior of the tire carcass and the tread support plies. This methodology has the capability of including centrifugal and friction forces. Finite difference methods are applied that produce reliable and accurate solutions of the tire response.

scholarly journals Identifying Vehicle Model Parameters Using Remote Mounted Motion Sensor

2021 ◽  
Author(s):  
Yoonjin Hwang
Keyword(s):  
Vehicle Dynamics ◽  
Model Parameters ◽  
Motion Sensor ◽  
Force Model ◽  
Single Track ◽  
Driver Assistance ◽  
Vehicle Model ◽  
Tire Force ◽  
Recent Developments ◽  
Potential Benefits

The recent developments on advanced driver assistance system(ADAS) have extended the capability of sensor systems from surrounding perception to motion estimation. The motion estima?tion provides tri-axial velocity and pose measurements, which open potential benefits for control and state estimation through sensor fusion with the vehicle dynamics model. In this paper we propose an identification method for the vehicle single track model parameters including the relative distance between the vehicle center of gravity and the motion sensor. A linearized tire force model and simplified single track vehicle model are constructed with the corresponding sensor kinematics model. We demonstrate the efficacy of iden?tification performance of the proposed method and confirm the feasibility of the usage of ADAS sensor in vehicle dynamics and vice versa

Performance comparison of electric-vehicle drivetrain architectures from a vehicle dynamics perspective

2019 ◽  
Vol 234 (4) ◽  
pp. 915-935
Author(s):  
Kerem Bayar
Keyword(s):  
Electric Vehicle ◽  
Control Strategy ◽  
Vehicle Dynamics ◽  
Tracking Control ◽  
Tracking Error ◽  
Vehicle Stability ◽  
Electric Motors ◽  
Sideslip Angle ◽  
Stopping Distance ◽  
Braking System

Recent electric vehicle studies in literature utilize electric motors within an anti-lock braking system, traction-control system, and/or vehicle-stability controller scheme. Electric motors are used as hub motors, on-board motors, or axle motors prior to the differential. This has led to the need for comparing these different drivetrain architectures with each other from a vehicle dynamics standpoint. With this background in place, using MATLAB simulations, these three drivetrain architectures are compared with each other in this study. In anti-lock braking system and vehicle-stability controller simulations, different control approaches are utilized to blend the electric motor torque with hydraulic brake torque; motor ABS, torque decomposition, and optimal slip-tracking control strategies. The results for the anti-lock braking system simulations can be summarized as follows: (1) Motor ABS strategy improves the stopping distance compared to the standard anti-lock braking system. (2) In case the motors are not solely capable of providing the required braking torque, torque decomposition strategy becomes a good solution. (3) Optimal slip-tracking control strategy improves the stopping distance remarkably compared to the standard anti-lock braking system, motor anti-lock braking system, and torque decomposition strategies for all architectures. The vehicle-stability controller simulation results can be summarized as follows: (1) higher affective wheel inertia of the on-board and hub motor architecture dictates a higher need of wheel torque in order to generate the tire force required for the desired yaw rate tracking. A higher level of torque causes a higher level of tire slip. (2) Optimal slip-tracking control strategy reduces the tire slip trends drastically and distributes the traction/braking action to each tire with the control-allocation algorithm specifying the reference slip values. This reduces reference tire slip-tracking error and reduces vehicle sideslip angle. (3) Tire slip trends are lower with the hub motor architecture, compared to the other architectures, due to more precise slip control.

Integration of Geometry and Analysis for the Study of Liquid Sloshing in Vehicle System Dynamics

2017 ◽  
Author(s):  
Brynne Nicolsen ◽  
Huailong Shi ◽  
Liang Wang ◽  
Ahmed A. Shabana
Keyword(s):  
Rigid Body ◽  
Vehicle Dynamics ◽  
Three Dimensional ◽  
Rigid Body Dynamics ◽  
Liquid Sloshing ◽  
Inertia Force ◽  
Vehicle Stability ◽  
Vehicle Model ◽  
Rail Vehicle ◽  
Curve Negotiation

Commonly-used sloshing models are either unable to capture changes in the continuous distribution of the fluid free surface, or are not suited for the integration with high fidelity computational multibody system (MBS) algorithms. The objective of this investigation is to address this deficiency by developing a new continuum-based liquid sloshing approach that accounts for the effect of complex fluid and tank geometry and can be systematically integrated with MBS algorithms in order to allow for studying complex motion scenarios. A unified geometry/analysis mesh is used from the outset to examine the effect of liquid sloshing on railroad and highway vehicle dynamics during various maneuvers including braking and curve negotiation [1,2]. Using a non-modal approach, the geometry of the tank and fluid is accurately defined, a continuum-based fluid constitutive model is developed, and a fluid-tank contact algorithm using the penalty approach is employed. In order to examine the effect of liquid sloshing on vehicle dynamics during curve negotiation, a general and precise definition of the outward inertia force is defined, which for flexible bodies does not take the simple form used in rigid body dynamics. During maneuvers, the liquid may experience large displacements and significant changes in shape that can be captured effectively using absolute nodal coordinate formulation (ANCF) finite elements. For rail systems, the liquid sloshing model is integrated with a three-dimensional MBS vehicle algorithm, in which the three-dimensional wheel/rail contact force formulation is used to account for the longitudinal, lateral, and spin creep forces that influence vehicle stability. The effects of fluid sloshing on vehicle dynamics in the case of a tank partially filled with liquid are studied and compared with the equivalent rigid body model in braking and curve negotiation. The results obtained in the study of the rail vehicle model show that liquid sloshing can exacerbate the unbalance effects when the rail vehicle negotiates a curve at a velocity higher than the balance speed, and can significantly increase coupler forces during braking. Analysis of the highway vehicle model shows that the liquid sloshing changes the contact forces between the tires and the ground — increasing the forces on certain wheels and decreasing the forces on other wheels — which in cases of extreme sloshing, can negatively impact the vehicle stability by increasing the possibility of wheel lift and vehicle rollover.

Vehicle Stability Improvement by Active Front Steering Control

2007 ◽  
Author(s):  
Deling Chen ◽  
Chengliang Yin ◽  
Li Chen
Keyword(s):  
Time Estimation ◽  
Linear Quadratic Regulator ◽  
Steering System ◽  
Angle Measurement ◽  
Vehicle Stability ◽  
Steering Control ◽  
Linear Quadratic ◽  
Sideslip Angle ◽  
Feedback Parameter ◽  
Active Front Steering

This paper presents the vehicle stability improvement by active front steering (AFS) control. Firstly, a mathematical model of the steering system incorporating vehicle dynamics is analyzed based on the structure of the AFS system. Then feedback controller with linear quadratic regulator (LQR) optimization is proposed. In the controller, the assisted motor in the system is controlled by the combination of feedforward method and feedback method. And the feedback parameter is the yaw rate together with the sideslip angle. Due to the difficulties associated with the sideslip angle measurement of vehicle, a state observer is designed to provide real time estimation to meet the demands of feedback. In the last, the system is simulated in MATLAB. The results show that the vehicle handling stability is improved with the AFS control, and the effectiveness of the control system is demonstrated.

A Full Vehicle Model for the Development of a Variable Camber Suspension

2007 ◽  
Author(s):  
Isao Kuwayama ◽  
Fernando Baldoni ◽  
Federico Cheli
Keyword(s):  
Simulation Models ◽  
Dynamics Simulation ◽  
Tire Model ◽  
Electronic Components ◽  
Vehicle Model ◽  
Active Systems ◽  
Additional Degree ◽  
Vehicle Simulation ◽  
Full Vehicle ◽  
Multi Body

The accuracy of the recent vehicle dynamics simulation technology, represented by Multi-Body Simulations along with reliable tire models, has been remarkably progressing and provides reasonable simulation results not only for conventional passive vehicles but also for advanced active vehicles equipped with electronic components; however, when it comes to advanced vehicle applications with complex active systems, the complexity causes a longer simulation time. On the other hand, even though simple numerical vehicle simulation models such as single-track, two-track and a dozen degrees of freedom (dofs) models can provide less information than those of multi-body models, they are still appreciated by specific applications particularly the ones related to the development of active systems. The advantages of these numerical simulation models lie in the simulation platform, namely the Matlab/Simulink environment, which is suitable for modeling electronic components. In this paper, an 18 dofs vehicle model has been proposed for the development of a type of active suspension named Variable Camber which has an additional degree of freedom in camber angle direction and a description of the models and some preliminary results are reported: the control strategy for the variable camber suspension will be published ([3]). The model can reproduce a passive vehicle with a passive suspension as well; all the necessary dimensions, parameters, and physical properties are derived from a specific multi-body full vehicle model which has been fully validated with respect to a real one on the track. As for a tire model, Magic Formula 5.2 has been implemented on both the numerical and the multi-body vehicle models respectively so that the same tire model can be applied.

An Adaptive Observer for Sideslip Angle Estimation: Comparison With Experimental Results

2007 ◽  
Author(s):  
Federico Cheli ◽  
Stefano Melzi ◽  
Edoardo Sabbioni
Keyword(s):  
Vehicle Dynamics ◽  
Adaptive Observer ◽  
Single Track ◽  
Vehicle Model ◽  
Weighted Mean ◽  
Sideslip Angle ◽  
Kinematic Formula ◽  
Angle Estimation ◽  
Lateral Vehicle Dynamics ◽  
Transitory Phase

By observing the lateral vehicle dynamics and in particular the sideslip angle, the detection of critical driving situations is possible. Thus, an adaptive observer for sideslip angle estimation is proposed in this paper. According to the proposed methodology, the sideslip angle is estimated as a weighted mean of the results provided by a kinematic formula and the ones obtained using a state observer based on a linear single-track vehicle model; tires cornering stiffness are updated during the transitory phase of a maneuver in order to take into account nonlinearities and changing of adherence conditions between tires and road.

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