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.

Simulation for Handing and Stability of Vehicle Based on SimulationX

2011 ◽  
Vol 291-294 ◽  
pp. 537-541
Author(s):  
Yong Xin Cao ◽  
Yan Fang Liu ◽  
Xiang Yang Xu ◽  
Yang Yang
Keyword(s):  
Degrees Of Freedom ◽  
Steering Wheel ◽  
Vehicle Model ◽  
Important Work ◽  
Sinusoidal Input ◽  
Changing Trend ◽  
Virtual Prototyping Technology ◽  
Time Domain Response ◽  
Multi Body ◽  
The Impact

To build a dynamic vehicle model is the most important work in the field of digital virtual prototyping technology for studying on its handing and stability. A 54 degrees of freedom multi-body vehicle model with tire, suspension and steering was established in SimulationX software. Time domain response under steering wheel step input and frequency response under steering wheel sinusoidal input were obtained, the changing trend of indicators with different speeds was presented, the handing and stability of vehicle model was evaluated, also the impact of caster angle and kingpin inclination to handing and stability was analyzed. The simulation results were consistent with theoretical analysis and actual situation.

Stability of Controlled Road Vehicles: A Preliminary Fundamental Study

2015 ◽  
Author(s):  
Fabio della Rossa ◽  
Massimiliano Gobbi ◽  
Giampiero Mastinu ◽  
Carlo Piccardi ◽  
Giorgio Previati
Keyword(s):  
Autonomous Vehicles ◽  
Autonomous Vehicle ◽  
Preliminary Investigation ◽  
Basin Of Attraction ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Vehicle Speed ◽  
Vehicle Model ◽  
The Stability ◽  
Positive Effect

A comparison of the lateral stability behaviour between an autonomous vehicle, a vehicle with driver and a vehicle without driver (fixed steering wheel) is made by introducing a simple mathematical model of a vehicle running on even road. The mechanical model of the vehicle has two degrees of freedom and the related equations of motion contain the nonlinear tyre characteristics. The driver is described by a well-known model proposed in the literature. The autonomous vehicle has a virtual driver (robot) that behaves substantially like a human, but with its proper reaction time and gain. The road vehicle model has been validated. The study of vehicle stability has to be based on bifurcation analysis and a preliminary investigation is proposed here. The accurate computation of steady-state equilibria is crucial to study the stability of the three kinds of vehicles here compared. The stability of the bare vehicle without driver (fixed steering wheel) is studied in a rather complete way referring to a number of combinations of tyre characteristics. The (known) conclusion is that the understeering vehicle is stable at each lateral acceleration level and at each vehicle speed. The additional (partially unknown) conclusion is that the vehicle (model) with degradated tyres may exhibit a huge number of different bifurcations. The driver has many effects on the stability of the vehicle. One positive effect is to eliminate the many possible different equilibria of the bare vehicle and keep active one single equilibrium only. Another positive effect is to broaden the basin of attraction of stable equilibria (at least at relatively low speed). A negative effect is that, even for straight running, the driver seem introducing a subcritical Hopf bifurcation which limits the maximum forward speed of some understeering vehicles (that could run faster with fixed steering wheel). Both the mentioned positive and negative effects appear to be applicable to autonomous vehicles as well. Further studies could be useful to overcome the limitations on the stability of current autonomous vehicles that have been identified in the present research.

Comparative Analysis of MacAdam Model and PI Control in a Predictive Driver Model

2021 ◽  
Vol 13 (4) ◽  
Author(s):  
C. Dias ◽  
J. Landre ◽  
P. Americo ◽  
M. Campolina ◽  
L. Marino Marino ◽  
...  
Keyword(s):  
Autonomous Vehicles ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Longitudinal Velocity ◽  
Pi Controller ◽  
Driver Model ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Reference Path ◽  
Double Lane Change

Autonomous vehicles are the future of automotive engineering and understanding how this systems work is critical. In these vehicles, controller models are usually needed to generate signals that would normally be imposed by the driver e.g., steering angles, acceleration inputs and braking commands. Intuitively, each control method utilized has its peculiarities and presents different behaviours. In such situation, this paper aims to develop an error comparison between a car displacement and its reference path due the use of two different predictive driver controllers: The proportional-integrative and the MacAdam model. For this purpose, a 14 degrees of freedom vehicle model is used with the aid of MATLAB Simulink, whereas simulations were made using the double-lane change manoeuvre, a commonly used manoeuvre to analyse the vehicle dynamics performance. At the end of this paper, lateral acceleration, displacement and steering wheel angle analysis led the conclusion that the vehicle behaviour is smoother with the use of the proportional-integrative control regardless of longitudinal velocity. Nevertheless, the trajectory error is smaller for MacAdam model than PI controller is and therefore it is easier to follow the reference path with this one, although in aggressive maneuverers it can cause more discomfort and increase the risk of rolling when compared to the PI controller in a vehicle with the same body stiffness.

scholarly journals Modal dynamics of structures with bladed isotropic rotors and its complexity for two-bladed rotors

2016 ◽  
Vol 1 (2) ◽  
pp. 271-296 ◽  
Author(s):  
Morten Hartvig Hansen
Keyword(s):  
Fourier Series ◽  
Degrees Of Freedom ◽  
Mass Matrix ◽  
Single Mode ◽  
Model Parameters ◽  
System Matrix ◽  
Resonance Frequencies ◽  
Set Up ◽  
Truncated Fourier Series ◽  
Modal Dynamics

Abstract. The modal dynamics of structures with bladed isotropic rotors is analyzed using Hill's method. First, analytical derivation of the periodic system matrix shows that isotropic rotors with more than two blades can be represented by an exact Fourier series with 3/rev (three per rotor revolution) as the highest order. For two-bladed rotors, the inverse mass matrix has an infinite Fourier series with harmonic components of decreasing norm; thus, the system matrix can be approximated by a truncated Fourier series of predictable accuracy. Second, a novel method for automatically identifying the principal solutions of Hill's eigenvalue problem is introduced. The corresponding periodic eigenvectors can be used to compute symmetric and antisymmetric components of the two-bladed rotor motion, as well as the additional forward and backward whirling components for rotors with more than two blades. To illustrate the use of these generic methods, a simple wind turbine model is set up with three degrees of freedom for each blade and seven degrees of freedom for the nacelle and drivetrain. First, the model parameters are tuned such that the low-order modal dynamics of a three-bladed 10 MW turbine from previous studies is recaptured. Second, one blade is removed, leading to larger and higher harmonic terms in the system matrix. These harmonic terms lead to modal couplings for the two-bladed turbine that do not exist for the three-bladed turbine. A single mode of a two-bladed turbine will also have several resonance frequencies in both the ground-fixed and rotating frames of reference, which complicates the interpretation of simulated or measured turbine responses.

Research on the Effects of Tires on the Vehicle Handling

2014 ◽  
Vol 496-500 ◽  
pp. 744-748
Author(s):  
Huang Ming Chen ◽  
Kong Hui Guo
Keyword(s):  
Dynamic Response ◽  
Steering Wheel ◽  
Vehicle Dynamic ◽  
Vehicle Handling ◽  
Linear Fitting ◽  
Sinusoidal Input ◽  
Mechanics Characteristic ◽  
The Difference ◽  
Set Up ◽  
The Mathematical Model

It is very important for vehicle handling to match right tires. Mechanics characteristic test is done for the different type tire, the mathematical model is set up according to test data. A dynamic model of vehicle is set up to study the effect of tire performance to vehicle handling stability. Vehicle dynamic response is researched on sinusoidal input of the steering wheel angle. Linear fitting of vehicle dynamic response is done in linear region. According to the difference between the simulation value and linear fitting, different tires are rated.

Influence of ride motions on the handling behaviour of a passenger vehicle

2005 ◽  
Vol 219 (9) ◽  
pp. 1047-1058 ◽  
Author(s):  
B Mashadi ◽  
D A Crolla
Keyword(s):  
Lateral Force ◽  
The Body ◽  
Road Surface ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Slip Angle ◽  
Vehicle Model ◽  
Body Side ◽  
Road Profile ◽  
Road Surfaces

A vehicle model was developed for the investigation of the influence of ride motions on handling dynamics of passenger vehicles. The inputs to the vehicle model are the steering wheel angle and a road profile at each wheel. The outputs were first compared with the results of independent handling and ride models, and good agreement was shown to exist. The combined motion of the vehicle was investigated by the application of step steering wheel angle inputs while travelling on a rough road surface. It was seen that the cornering ability at low and moderate levels of lateral acceleration on the roads with moderate roughness was similar to that on the smooth road, but larger body side-slip angles and tyre slip angles occurred over the rough road surfaces for similar steering inputs. The maximum achievable lateral acceleration was reduced on roads with moderate roughness owing to the earlier saturation of tyre slip angles compared with those on smooth roads. Over very rough roads and at high lateral accelerations, because of the large fluctuations of normal loads and the rapid drop in available lateral force, the body side-slip angle dramatically increased, which led to instability characterized by the oversteering behaviour. At high lateral accelerations close to the limit, the vehicle that understeered over the smooth road surface exhibited oversteering behaviour over rough road surfaces.

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.

The scientific bases of autocontrol with vibration phase for a resonance beating-vibration system with two degrees of freedom driven by debalances

1996 ◽  
Vol 18 (2) ◽  
pp. 43-48
Author(s):  
Tran Van Tuan ◽  
Do Sanh ◽  
Luu Duc Thach
Keyword(s):  
Degrees Of Freedom ◽  
Regulation System ◽  
Vibration System ◽  
Two Degrees Of Freedom ◽  
System Operating

In the paper it is introduced a method for studying dynamics of beating-vibrators by means of digital calculation with the help of the machine in accordance with the needs by the helps of an available auto regulation system operating with high reability.

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