Rationale for a new vehicle dynamic convention

2020 ◽  
pp. 107754632093983
Author(s):  
Dan Williams ◽  
Don Margolis
Keyword(s):  
Vehicle Dynamics ◽  
Research Result ◽  
Slip Angle ◽  
Clear Definition ◽  
Vehicle Dynamic ◽  
Conventional Model ◽  
Accepted Standard ◽  
New Research

The term “slip angle” has been inconsistently applied in the vehicle dynamics field for some time, even in the presence of a clear definition in the SAE J670 standard defining vehicle dynamic terms. This work proposes the opposite of the Society of Automotive Engineers slip angle convention, not a completely unknown concept in the literature. This proposed slip angle convention is combined with a simple yet novel convention change for axle location. Differences between the conventional model and the new conventions are discussed, and the differences between the proposed convention and SAE J670 are clearly delineated. This work is intended as a reference to be used in the vehicle dynamics community by any researcher wishing to work with a model more intuitively pleasing and widely applicable than the accepted standard. This work does not present a particular new research result. Rather, it provides context on the often confusing choice of vehicle dynamic conventions and suggests a preferable selection.

Dynamic Modeling, Theory and Application Using Bond Graph

2015 ◽  
Vol 4 (1) ◽  
Author(s):  
Bharat Raj Singh ◽  
Manoj Kumar Singh
Keyword(s):  
Dynamic System ◽  
Modeling And Simulation ◽  
Vehicle Dynamics ◽  
Bond Graph ◽  
Vehicle Dynamic ◽  
Shape Factors ◽  
Turn Angle ◽  
System Equation ◽  
Relative Contribution ◽  
Result Analysis

The paper describes the technique for presenting quantitative and systematic modeling and simulation using Bond Graph for the vehicle dynamic system. It is based on the relative contribution of the new generation of a system equation, expression, result analysis and simulation through graphical display. The portioning algorithm can be employed to the existing automated modeling techniques for efficient, accurate simulation towards the design of the vehicle dynamic system. The design of control oriented four wheeled vehicle is widely recognized to be a very challenging task. This allows accounting for the driver turn angle which necessitates about visualizing the real driving behavior and its effects on the overall vehicle dynamic system. The study also illustrates an introduction to vehicle dynamics with emphasis towards the influence of its various properties. It also discusses the steady–state behavior of simple automobile models and transient motion when small and large steering inputs and other disturbances are employed. The effect of various shape factors and type of characteristics on vehicle handling properties is analysed. In order to design a controller, a good model representing the dynamic system is needed. From the input parameters considered, the results of the modeling and simulation of vehicle dynamics through the Bond Graph are found efficient and more accurate.

Vehicle dynamics of a high-speed passenger car due to aerodynamics inside tunnels

2007 ◽  
Vol 221 (4) ◽  
pp. 527-545 ◽  
Author(s):  
B Diedrichs ◽  
M Berg ◽  
S Stichel ◽  
S Krajnović
Keyword(s):  
Vehicle Dynamics ◽  
High Speed ◽  
Ride Comfort ◽  
Sensitivity Study ◽  
Response Analysis ◽  
Vehicle Dynamic ◽  
Aerodynamic Loads ◽  
Car Body ◽  
Unsteady Aerodynamic ◽  
Multi Body

High train speeds inside narrow double-track tunnels using light car bodies can reduce the ride comfort of trains as a consequence of the unsteadiness of the aerodynamics. This fact was substantiated in Japan with the introduction of the series 300 Shinkansen trains more than a decade ago, where the train speed is very high also in relatively narrow tunnels on the Sanyo line. The current work considers the resulting effects of vehicle dynamics and ride comfort with multi-body dynamics using a model of the end car of the German high-speed train ICE 2. The present efforts are different from traditional vehicle dynamic studies, where disturbances are introduced through the track only. Here disturbances are also applied to the car body, which conventional suspension systems are not designed to cope with. Vehicle dynamic implications of unsteady aerodynamic loads from a previous study are examined. These loads were obtained with large eddy simulations based on the geometry of the ICE 2 and Shinkansen 300 trains. A sensitivity study of some relevant vehicle parameters is carried out with frequency response analysis (FRA) and time domain simulations. A comparison of these two approaches shows that results which are obtained with the much swifter FRA technique are accurate also for sizable unsteady aerodynamic loads. FRA is, therefore, shown to be a useful tool to predict ride comfort in the current context. The car body mass is found to be a key parameter for car body vibrations, where loads are applied directly to the car body. For the current vehicle model, a mass reduction of the car body is predicted to be most momentous in the vicinity of 2 Hz.

scholarly journals A Novel Dynamic Data Driven Tire Model

2021 ◽  
Author(s):  
Junning Zhang ◽  
Shaopu YANG ◽  
Yongjie LU
Keyword(s):  
Experimental Data ◽  
Knowledge Base ◽  
Vehicle Dynamics ◽  
Mechanical Characteristics ◽  
Slip Rate ◽  
Lateral Force ◽  
Longitudinal Force ◽  
Dynamics Simulation ◽  
Slip Angle ◽  
Tire Model

Abstract In the study of vehicle dynamics, the accurate description of tire mechanical characteristics is the basis and key of vehicle dynamics simulation. An innovative tire model is proposed based on fuzzy algorithm and a sinusoidal membership function is used to design fuzzy rules. In order to ensure the accuracy of tire behavior calculation, this model is driven by a small amount of experimental data of tire mechanical characteristics. This tire model consists of four layers of fuzzy systems, each of which has a knowledge base. The data in knowledge base I is obtained by experiments, and the data of knowledge base II is computed by the upper system, and so is the later system. Then, the input signal, the change rate of side slip angle and slip rate, is considered to improve the calculation accuracy of the model. The proposed fuzzy tire model can accurately predict the longitudinal force, lateral force and self-aligning torque of the tire under unknown conditions. Finally, by comparing the fuzzy tire model with the experimental data, it is found that the maximum RRMSE (Relative Root Mean Square Error) value is not more than 0.14. It is proved that the model can accurately describe the tire
mechanical characteristics under combined conditions.

Flexible Wheel/Rail Contact Model for Railway Vehicle Dynamics Without Pre-Calculation

2007 ◽  
Author(s):  
Mohammad Durali ◽  
S. Hassan Salehi ◽  
Mohammad Mehdi Jalili
Keyword(s):  
Vehicle Dynamics ◽  
Contact Forces ◽  
Contact Model ◽  
Railway Vehicle ◽  
Dynamic Problems ◽  
Vehicle Dynamic ◽  
Rail Vehicle ◽  
Rigid Contact ◽  
Contact Situation ◽  
Contact Mechanism

An advanced method using progressive concept of geometrical correspondence is applied to create a new wheel/rail contact model based on virtual penetration theory. The geometry and contact mechanism are solved simultaneously because of the independency in a defined correspondence. The model takes the penetrated profiles of wheel and rail and also associated creeps as inputs, and produces driving contact forces as output. The advantage of this model is that it doesn’t require pretabulation of rigid contact situation. The method allows calculating flexible, non-elliptical, multiple contact patches during integration of the model. Consequently the rails with substructures can vibrate separately from the vehicle in a flexible wheel/rail contact model. The simulation results indicate that this method can be used in various rail vehicle dynamic problems.

Design of an Optimal Control Strategy for an Active Front Steering System

2006 ◽  
Author(s):  
Avesta Goodarzi ◽  
Ebrahim Esmailzadeh ◽  
Babak Nadarkhani
Keyword(s):  
Optimal Control ◽  
Vehicle Dynamics ◽  
Steering System ◽  
Lateral Acceleration ◽  
Manufacturing Companies ◽  
Vehicle Dynamic ◽  
Steering Control ◽  
Optimal Control Strategy ◽  
Active Front Steering ◽  
Innovative System

The concept of active steering control (ASC) has been considered by several researchers as well as auto manufacturing companies during recent years. This innovative system permits any correction of the driver’s steering angle in order to achieve the desired vehicle dynamic behavior. An optimal control law to evaluate the steering angle’s correction of the front wheels, being part of an active front steering system (AFS), has been developed. For this purpose a specific lateral vehicle dynamics index is defined in which way that the minimization of the performance index lead to improved vehicle dynamics. The optimal values of the control law’s gains are determined analytically. The performance of the proposed control system has been verified using 8-DOF nonlinear vehicle dynamic model. The simulation results illustrate that considerable improvement in vehicle handling is achieved particularly for the cases of the low and mid-range lateral acceleration maneuvers.

Wheelbase Filtering and Characterization of Road Profiles for Vehicle Dynamics

2010 ◽  
Author(s):  
Dongpu Cao ◽  
Amir Khajepour ◽  
Xubin Song
Keyword(s):  
Vehicle Dynamics ◽  
Dynamic Performance ◽  
Dynamic Responses ◽  
Vehicle Dynamic ◽  
Road Roughness ◽  
Significant Difference ◽  
Study Characteristics ◽  
Filtering Effect ◽  
Positive Effect

Random road profiles and wheelbase filtering, both of which strongly affect vehicle dynamic performance characteristics, have been explored in many studies. These studies invariably focused on either characterizing road roughness or vehicle dynamics considering wheelbase filtering effect. No effort, however, has been attempted to characterize road roughness profiles upon considering vehicle wheelbase filtering effect, and then to investigate their combined roles on vehicle dynamic responses. In this study, characteristics of different random road profiles are investigated upon considering wheelbase filtering effect. Two vehicle models, including quarter-car and pitch-plane models, are then employed to analyze the combined influence of random road roughness and wheelbase filtering on vehicle dynamics. The simulation results reveal the significant difference between the characteristics of random road profiles with and without wheelbase filtering effect. The results further demonstrate that wheelbase filtering has a positive effect on vehicle vertical ride, with a negligible or small compromise on suspension travel and dynamic tire deflection.

Active Kinematics Suspension Integrating Milliken Moment Method in the Control Logic

2016 ◽  
Author(s):  
Isabel Ramirez Ruiz ◽  
Edoardo Sabbioni ◽  
Federico Cheli
Keyword(s):  
Vehicle Dynamics ◽  
Moment Method ◽  
Full Range ◽  
Operating Conditions ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Slip Angle ◽  
Control Logic ◽  
Sideslip Angle ◽  
Vehicle Dynamics Control

The idea behind the active kinematics suspension is to enhance its performance of vehicle dynamics. This includes improve steady and dynamic limit stability and faster transient reaction through optimized lateral and longitudinal dynamics. The driver’s benefits are: improved safety and higher driving pleasure. To achieve more control over the position of the rear wheels and thus the tire contact patch on the ground, the active suspension introduces one independent linear actuator at each rear wheel that controls the wheels’ camber freely. This paper will present the vehicle dynamics control logic methodology of a rear active vehicle suspension implementing the Milliken Moment Method (MMM) diagram to improve the vehicle stability and controllability, achieving gradually the front and rear axle limits. A Multibody vehicle model has been used to achieve a high fidelity simulation to generate the Milliken Moment Diagram (MMD) also known as the CN-AY diagram, where the vehicle’s yaw moment coefficient (CN) about the CG versus its lateral acceleration (AY) is mapped for different vehicle sideslip angle and steering wheel angles. With the Moment Method computer program it is possible to create the limit of the diagram over the full range of steering wheel angle and side slip angle for numerous changes in vehicle configuration of rear camber wheels and operating conditions. The vehicle dynamics control logic uses the maps like a vehicle maneuvering area under different vehicle active configurations where vehicle’s control is most fundamentally expressed as a yawing moment to quantify the directional stability.

Vehicle side-slip angle estimation on a banked and low-friction road

2017 ◽  
Vol 232 (12) ◽  
pp. 1584-1596 ◽  
Author(s):  
Martin Haudum ◽  
Johannes Edelmann ◽  
Manfred Plöchl ◽  
Manuel Höll
Keyword(s):  
Vehicle Dynamics ◽  
Stability Control ◽  
Velocity Estimation ◽  
Slip Angle ◽  
State Variables ◽  
Low Friction ◽  
Bank Angle ◽  
Angle Estimation ◽  
Side Slip Angle ◽  
Handling Characteristics

The effective application of integrated vehicle dynamics control and automatic driving require consistent vehicle state variables and parameters. Considering lateral vehicle dynamics, the yaw rate and (estimated) vehicle side-slip angle are the minimum set of state variables that can give insight into the handling characteristics of a vehicle. Various methods of vehicle side-slip angle (lateral velocity) estimation have been tested in virtual and real world applications, in particular on a horizontal dry road. Vehicle side-slip angle, however, is not only affected by the (steering) commands of the driver, and possibly by a vehicle dynamics controller, but can also arise from a banked road or result from a low-friction surface, changing tyre–road contact. The combined effects require a comprehensive estimation approach, which is less often touched upon in the literature. Based on earlier findings on important aspects of observability, the paper addresses a modular vehicle side-slip angle estimation approach that is particularly focused upon practical aspects of modelling and design. Estimation of the combined vehicle side-slip angle, road bank angle and maximum tyre–road friction coefficient has been broadly tested with a vehicle equipped with an electronic stability control (ESC) and electric power-assisted steering (EPS) sensor configuration, for various road conditions, driving situations and vehicle/tyre setups.

Vehicle side-slip angle estimation based on vehicle dynamics and nonlinear observers

2008 ◽  
Author(s):  
Guo Hongyan ◽  
Chen Hong ◽  
Ding Haitao ◽  
Bi Chunguang ◽  
Zhao Haiyan
Keyword(s):  
Vehicle Dynamics ◽  
Slip Angle ◽  
Angle Estimation ◽  
Side Slip Angle ◽  
Nonlinear Observers
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