Multiple Limit Cycles Shimmy of the Dual-Front Axle Steering Heavy Truck Based on Bisectional Road

2019 ◽  
Vol 14 (5) ◽  
Author(s):  
Daogao Wei ◽  
Yingjie Zhu ◽  
Tong Jiang ◽  
Andong Yin ◽  
Wenhao Zhai
Keyword(s):  
Dynamic Model ◽  
Limit Cycle ◽  
Dry Friction ◽  
Bifurcation Theory ◽  
Steering System ◽  
Front Axle ◽  
Adhesion Coefficient ◽  
The Road ◽  
Heavy Truck ◽  
Multiple Limit Cycle

The shimmy problem causes considerable harm to vehicles and is difficult to solve, especially multiple limit cycle shimmy. Moreover, the dynamic behavior of the multiple limit cycle shimmy of vehicles based on a bisectional road is more complex. Shimmy is practically observed in trucks of cooperative factories during utilization. Thus, we take a heavy truck of a cooperative factory as the prototype and establish a dynamic model of the vehicle-road coupling shimmy system, considering the road adhesion coefficient and dry friction between the suspension and steering system. Based on the dynamic model, the Hopf bifurcation theory is used to qualitatively analyze the existence of the limit cycle for the vehicle shimmy system, and the multiple limit cycle shimmy phenomenon is successfully reproduced using a numerical method. Moreover, the effect of the road adhesion coefficient on the multiple limit cycle shimmy characteristic is studied. Results show that the speed interval and amplitude of the multiple limit cycle shimmy decrease with the road adhesion coefficient; when the coefficient is reduced to a certain extent, the multiple limit cycle shimmy phenomenon is not observed. In addition, the adhesion coefficient of the second axle has a stronger effect on the shimmy characteristic than that of the first axle.

scholarly journals Hopf Bifurcation Characteristics of Dual-Front Axle Self-Excited Shimmy System for Heavy Truck considering Dry Friction

2015 ◽  
Vol 2015 ◽  
pp. 1-20 ◽  
Author(s):  
Daogao Wei ◽  
Ke Xu ◽  
Yibin Jiang ◽  
Changhe Chen ◽  
Wenjing Zhao ◽  
...  
Keyword(s):  
Hopf Bifurcation ◽  
Dry Friction ◽  
Steering System ◽  
Front Axle ◽  
Friction Torque ◽  
The Self ◽  
Lagrange’S Equation ◽  
Excited Vibration ◽  
Heavy Truck ◽  
Manifold Theory

Multiaxle steering is widely used in commercial vehicles. However, the mechanism of the self-excited shimmy produced by the multiaxle steering system is not clear until now. This study takes a dual-front axle heavy truck as sample vehicle and considers the influences of mid-shift transmission and dry friction to develop a 9 DOF dynamics model based on Lagrange’s equation. Based on the Hopf bifurcation theorem and center manifold theory, the study shows that dual-front axle shimmy is a self-excited vibration produced from Hopf bifurcation. The numerical method is adopted to determine how the size of dry friction torque influences the Hopf bifurcation characteristics of the system and to analyze the speed range of limit cycles and numerical characteristics of the shimmy system. The consistency of results of the qualitative and numerical methods shows that qualitative methods can predict the bifurcation characteristics of shimmy systems. The influences of the main system parameters on the shimmy system are also discussed. Improving the steering transition rod stiffness and dry friction torque and selecting a smaller pneumatic trail and caster angle can reduce the self-excited shimmy, reduce tire wear, and improve the driving stability of vehicles.

scholarly journals Effect of Road Profile on Suspension System of Heavy Truck

2019 ◽  
Vol 12 (2) ◽  
pp. 71-75
Author(s):  
Salem F. Salman
Keyword(s):  
Steering System ◽  
Suspension System ◽  
The Road ◽  
Road Profile ◽  
Road Roughness ◽  
Road Type ◽  
Heavy Truck ◽  
Main Factors ◽  
On The Road ◽  
The Stability

All vehicles are affected by the type of the road they are moving on it.  Therefore the stability depends mainly on the amount of vibrations and steering system, which in turn depend on two main factors: the first is on the road type, which specifies the amount of vibrations arising from the movement of the wheels above it, and the second on is the type of the used suspension system, and how the parts connect with each other. As well as the damping factors, the tires type, and the used sprungs. In the current study, we will examine the effect of the road roughness on the performance coefficients (speed, displacement, and acceleration) of the joint points by using a BOGE device.

scholarly journals ANALYSIS OF THE IMPACT OF VARIOUS PRESSURES IN THE VEHICLE WHEELS ON THE WHEEL GEOMETRY

2021 ◽  
Vol 1 (50) ◽  
pp. 210-220
Author(s):  
LEW K ◽  
Keyword(s):  
Automatic Device ◽  
Steering System ◽  
Front Axle ◽  
Air Pressure ◽  
Steering Wheel ◽  
The Road ◽  
Significant Difference ◽  
On The Road ◽  
Toe Angle ◽  
The Impact

The steering system in a vehicle is one of the main systems that ensures its controllability and is important for road safety. The steering system consists of two main mechanisms, namely the steering gear, the task of which is to convert the rotary motion into reciprocating motion, and the steering gear, the task of which is to ensure the correct steering of the vehicle. In this case, the steering system is interconnected with the suspension of the car, in which there are four main angles of the wheels that are responsible for the correct maneuverability of the vehicle, namely: camber angle, toe angle, angle of rotation of the axle of the fist and the angle of inclination of the pivot axis of the fist. Measuring the geometry of a vehicle's suspension has several interrelated purposes. One of them is the modification of the stability of the vehicle, that is, the effective impact on the maintenance of the vehicle on the road. Handling also depends on the geometry setting and ensures proper maintenance on the road. Well adjusted geometry ensures even tire wear on each axle. The purpose of the steering system is to maintain the correct position of the steering wheel in relation to the steering wheels. The tests were carried out in stationary conditions at the diagnostic station of the Rzeszow University of Technology using an automatic device for measuring and regulating the air pressure in the tires of the Unitrol PA-10K car and the Launch X-631 car wheel alignment system. The object of the study was a passenger car of the Opel Agila brand. The tests were carried out for various values of air pressure in the car wheels. Based on the above, the task was set - to demonstrate how incorrect air pressure in the wheels of a car changes the angles of inclination of the wheels of the car. When analyzing the obtained test results, it was found that the pressure in the wheels, different from the nominal, but the same in each wheel, does not significantly affect the change in the values of the parameters of the angles of inclination of the vehicle wheels. If the pressure in the wheels on one side of the vehicle drops by 1 bar, there is a significant difference in the camber angles of the front axle. Changes in the air pressure in one of the rear wheels of the car do not significantly affect the angles of inclination of the car wheels. KEY WORDS: AIR PRESSURE IN THE WHEELS, UNEVEN PRESSURE, WHEEL MOUNTING ANGLES, CAMBER AND TOE ANGLES, STEERING.

Improved AEB algorithm combined with estimating the adhesion coefficient of road ahead and considering the performance of EHB

2021 ◽  
pp. 095440702110261
Author(s):  
Dequan Zeng ◽  
Zhuoping Yu ◽  
Lu Xiong ◽  
Junqiao Zhao ◽  
Peizhi Zhang ◽  
...  
Keyword(s):  
Joint Probability ◽  
Principal Component ◽  
Test Results ◽  
Safe Distance ◽  
Adhesion Coefficient ◽  
The Road ◽  
Response Characteristics ◽  
Emergency Braking ◽  
Multiple Beams ◽  
Maximum Method

This paper proposes an improved autonomous emergency braking (AEB) algorithm intended for intelligent vehicle. Featuring a combination with the estimation of road adhesion coefficient, the proposed approach takes into account the performance of electronic hydraulic brake. In order for the accurate yet fast estimate of road ahead adhesion coefficient, the expectation maximization framework is applied depending on the reflectivity of ground extracted by multiple beams lidar in four major steps, which are the rough extraction of ground points based on 3 σ criterion, the accurate extraction of ground points through principal component analysis (PCA), the main distribution characteristics of ground as extracted using the expectation maximum method (EM) and the estimation of road adhesion coefficient via joint probability. In order to describe the performance of EHB, the response characteristics, as well as the forward and adverse models of both braking pressure and acceleration are obtained. Then, with two typical roads including single homogeneous road and fragment pavement, the safe distance of improved AEB is modeled. To validate the algorithm developed in this paper, various tests have been conducted. According to the test results, the reflectivity of laser point cloud is effective in estimating the road adhesion coefficient. Moreover, considering the performance of EHB system, the improved AEB algorithm is deemed more consistent with the practicalities.

Study on the Dynamics on the Brake of Vehicle after the Effects of Deicing Salt

2010 ◽  
Vol 26-28 ◽  
pp. 862-869
Author(s):  
Tao Peng ◽  
Zhi Peng Li ◽  
Chang Shu Zhan ◽  
Xiang Luo ◽  
Qian Wang
Keyword(s):  
Simulation Model ◽  
Dynamic Model ◽  
The Other ◽  
Snow Melting ◽  
Adhesion Coefficient ◽  
Deicing Salt ◽  
Other Hand ◽  
Road Condition ◽  
Braking Distance ◽  
The Relationship

Through analyzing the process of brake, a dynamic model of automobile and a model of the relationship between braking distance and adhesion coefficient were formed; also a simulation calculating model of braking distance was established with the use of Matlab. Finally, a research was done toward the braking distance of a type of a car running on a road after using snow-melting agent. On one hand, with the application of the simulation model which has been established, calculations have been done to the braking distance of Bora vehicles running on roads after using deicing salt; on the other hand, by experiments, Bora vehicles’ braking distance and maximum braking deceleration under the same road condition were measured, meanwhile, the established simulation model was verified.

Analysis of the non-periodic oscillations of a self-excited friction-damped system with closely-spaced modes

2021 ◽  
Author(s):  
Lukas Woiwode ◽  
Alexander F. Vakakis ◽  
Malte Krack
Keyword(s):  
Hopf Bifurcation ◽  
Limit Cycle ◽  
Dry Friction ◽  
The Self ◽  
Perturbation Approach ◽  
Friction Damping ◽  
Periodic Oscillations ◽  
Analytical Results ◽  
Fold Bifurcation ◽  
Phase Motion

Abstract It is widely known that dry friction damping can bound the self-excited vibrations induced by negative damping. The vibrations typically take the form of (periodic) limit cycle oscillations. However, when the intensity of the self-excitation reaches a condition of maximum friction damping, the limit cycle loses stability via a fold bifurcation. The behavior may become even more complicated in the presence of any internal resonance conditions. In this work, we consider a two-degree-of-freedom system with an elastic dry friction element (Jenkins element) having closely spaced natural frequencies. The symmetric in-phase motion is subjected to self-excitation by negative (viscous) damping, while the symmetric out-of-phase motion is positively damped. In a previous work, we showed that the limit cycle loses stability via a secondary Hopf bifurcation, giving rise to quasi-periodic oscillations. A further increase of the self-excitation intensity may lead to chaos and finally divergence, long before reaching the fold bifurcation point of the limit cycle. In this work, we use the method of Complexification-Averaging to obtain the slow flow in the neighborhood of the limit cycle. This way, we show that chaos is reached via a cascade of period doubling bifurcations on invariant tori. Using perturbation calculus, we establish analytical conditions for the emergence of the secondary Hopf bifurcation and approximate analytically its location. In particular, we show that non-periodic oscillations are the typical case for prominent nonlinearity, mild coupling (controlling the proximity of the modes) and sufficiently light damping. The range of validity of the analytical results presented herein is thoroughly assessed numerically. To the authors' knowledge, this is the first work that shows how the challenging Jenkins element can be treated formally within a consistent perturbation approach in order to derive closed-form analytical results for limit cycles and their bifurcations.

Road Adhesion Coefficient Estimation Based on the Steering Wheel Rebound After Steering

2018 ◽  
Author(s):  
Liangyao Yu ◽  
Sheng Zheng ◽  
Xiaohui Liu ◽  
Jinghu Chang ◽  
Fei Li
Keyword(s):  
Stability Control ◽  
Front Wheel ◽  
Intelligent Vehicles ◽  
Steering Wheel ◽  
Adhesion Coefficient ◽  
The Road ◽  
Whole Process ◽  
Friction Moment ◽  
Stability Control System ◽  
The Coefficient Of Friction

Accurately estimating road adhesion coefficient is very important for vehicle stability control system. In this paper, an innovation method to estimate the road adhesion coefficient is proposed. This method can be used in vehicles without additional sensors. And this method is especially suitable to be used in the intelligent vehicle equipped with steer-by-wire (SBW) system. When vehicle steers, releasing the steering wheel suddenly will result in rebound to a certain angle. When the steer wheel turns the same angle on different road whose adhesion coefficients are different, the front wheel rebound angles are different. The friction moment between the road and tire is the main factor to prevent the tire from turning back, and the coefficient of friction is equal to road adhesion coefficient when the vehicle is stationary. In this paper, the detailed dynamical models describing the whole process of the front wheel and tire rebound are established. Furthermore, the Luenberger reduced-order disturbance observer is established to estimate the friction moment, and then the adhesion coefficient is estimated. The SBW system which is usually equipped in intelligent vehicles can control the steer moment and steer angle accurately. When the steer wheel turns to certain angle, the SBW system is able to stop outputting torque quickly and timely, which is important for improving the experiment accuracy. In this paper, the SBW system is used to conduct an experiment on different roads. The experiment results demonstrate the validity of this method.

Modeling and Controlling of Anti-Slip Regulation Based on Limited-Slip Differential

2011 ◽  
Vol 86 ◽  
pp. 762-766
Author(s):  
Jian Jun Hu ◽  
Peng Ge ◽  
Zheng Bin He ◽  
Da Tong Qin
Keyword(s):  
Dynamic Models ◽  
Fuzzy Controller ◽  
Rear Wheel ◽  
Pi Controller ◽  
Hydraulic Control ◽  
Electronic Throttle ◽  
Adhesion Coefficient ◽  
The Road ◽  
Wheel Drive ◽  
Hydraulic Control System

The dynamic models of whole rear-wheel drive vehicle, limited-slip differential, hydraulic control system and electronic throttle were established. Simulations of acceleration course on split-µ road, checkerboard-µ road, low-µ road and step-µ road were carried out combining electronic throttle PI controller and limited-slip differential fuzzy controller. The results show that the Anti-slip Regulation quickly works according to the road adhesion coefficient, effectively inhibits the slip of driving wheels on low adhesion coefficient road, the acceleration performance driving on bad roads was improved obviously, and show a good adaptability.

scholarly journals Analysis on the research method of road sense feedback in steer-by-wire system

2021 ◽  
Vol 2121 (1) ◽  
pp. 012031
Author(s):  
Chuanbin Wei ◽  
Lizhu Zhang ◽  
You Fu ◽  
Faying Xia
Keyword(s):  
Automobile Industry ◽  
Basic Structure ◽  
Steering System ◽  
Mechanical Transmission ◽  
Driving Experience ◽  
The Road ◽  
Establishment Method ◽  
Steer By Wire ◽  
Transmission Structure ◽  
Wire System

Abstract Nowadays, the automobile industry is gradually developing towards the trend of electrification and intelligence. Compared with the traditional steering system, the steer-by-wire system cancels the mechanical transmission structure, reduces the space utilization, reduces the probability of damage to the driver caused by the steering system in the collision accident, and improves the driving portability and enhances the driver’s handling experience. The road feeling feedback of steer-by-wire system has the greatest impact on the driver’s driving experience. This paper discusses the research methods of road feeling feedback of steer-by-wire system, introduces the basic structure of road feeling feedback of steer-by-wire system, the basic idea of dynamic modeling, the establishment of simulation model of road feeling feedback, and the establishment method of control strategy and simulation platform of road feeling feedback. Finally, it summarizes and prospects in order to provide basic information and perspectives for the development and research of steer-by-wire system.

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