scholarly journals Numerical Simulation Analysis of an Oversteer In-Wheel Small Electric Vehicle Integrated with Four-Wheel Drive and Independent Steering

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Izhar Ishak ◽  
Hirohiko Ogino ◽  
Yoshio Yamamoto
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Critical Velocity ◽  
High Speed ◽  
Simulation Analysis ◽  
Stability Limit ◽  
Conventional Vehicle ◽  
Wheel Drive ◽  
On The Road ◽  
Four Wheel Drive

Similar to conventional vehicle, most in-wheel small EVs that exist today are designed with understeer (US) characteristic. They are safer on the road but possess poor cornering performance. With recent in-wheel motor and steer-by wire technology, high cornering performance vehicle does not limit to sport or racing cars. We believe that oversteer (OS) design approach for in-wheel small EV can increase the steering performance of the vehicle. However, one disadvantage is that OS vehicle has a stability limit velocity. In this paper, we proposed a Four-Wheel Drive and Independent Steering (4WDIS) for in-wheel small EV with OS characteristic. The aim of implementing 4WDIS is to develop a high steer controllability and stability of the EV at any velocity. This paper analyses the performance of OS in-wheel small EV with 4WDIS by using numerical simulation. Two cornering conditions were simulated which are (1) steady-state cornering at below critical velocity and (2) steady-state cornering over critical velocity. The objective of the simulation is to understand the behavior of OS in-wheel small EV and the advantages of implementing the 4WDIS. The results show that an in-wheel small EV can achieve high cornering performance at low speed while maintaining stability at high speed.

Words, The Magic Kingdom

1996 ◽  
Author(s):  
Harvey S. Wiener
Keyword(s):  
Common Good ◽  
High Speed ◽  
Motor Vehicle ◽  
Life Forms ◽  
Common Ownership ◽  
Wheel Drive ◽  
Actual Meaning ◽  
The Many ◽  
Four Wheel Drive ◽  
The Military

When Alice faces the extraordinary Wonderland notions of saying what you mean and meaning what you say, she confronts language's great potential and disappointment. Words should, but do not always, mean what they say; and we who use them do not always produce what we mean. If only we could point to a direct correspondence between each word and only one exact meaning! Reading would simplify in a flash. Ah, but what we might gain in exactness and dazzling clarity, surely we would lose in flexibility, nuance, suggestiveness, and contextual richness. It's good that words have such a wide range of meanings and uses; as such they enrich our capabilities as earths highest life forms and its most competent communicators. Knowing the possibilities of language, understanding the many qualities of words and how our language depends on them, can enhance your child's attempts to determine meaning from print. In the long climb up the mountain to word mastery, a major feature of language that you can help your youngster understand is that words often mean more than they say. Certainly, words have denotative meanings. That is, words have exact definitions that you could check easily in a dictionary. A jeep is a heavy-duty, four-wheeled vehicle. A communist is someone who believes in a social and political system characterized by common ownership and labor organized for the common good. A frigate is a high-speed, medium-sized war vessel of the 17th, 18th, and 19th centuries. Yet each of these words has connotative meanings as well. What a word connotes is what it suggests or implies beyond its actual meaning—including the associations and feelings aroused by the word. A jeep is more than a motor vehicle with four-wheel drive; its connection with the military and rugged outdoor life suggests certain associations—rough riding, speed, even danger perhaps. Your son or daughter might like to ride to school in a jeep just for the fun of it, but you'd have 'been puzzled (to say nothing of your parents!) if your date for the senior prom honked the jeep horn outside your front door when he arrived to pick you up.

Added Stability Lobes in Machining Processes That Exhibit Periodic Time Variation, Part 1: An Analytical Solution

2004 ◽  
Vol 126 (3) ◽  
pp. 467-474 ◽  
Author(s):  
William T. Corpus ◽  
William J. Endres
Keyword(s):  
Numerical Simulation ◽  
Analytical Solution ◽  
Closed Form ◽  
High Speed ◽  
Stability Limit ◽  
Second Order ◽  
Machining Processes ◽  
Stability Lobes ◽  
Time Varying Systems ◽  
Computationally Intensive

An added family of stability lobes, which exists in addition to the traditional stability lobes, has been identified for the case of periodically time varying systems. An analytical solution of arbitrary order is presented that identifies and locates multiple added lobes. The stability limit solution is first derived for zero damping where a final closed-form symbolic result can be realized up to second order. The un-damped solution provides a mathematical description of the added lobes’ locations along the speed axis, an added-lobe numbering convention, and the asymptotes for the damped case. The derivation for the damped case permits a final closed-form symbolic result for first-order only; the second-order solution requires numerical evaluation. The easily computed analytical solution is shown to agree well with the results of the computationally intensive numerical simulation approach. An increase in solution order improves the agreement with numerical simulation; but, more importantly, it allows equivalently more added lobes to be predicted, including the second added lobe that cuts into the speed regime of the traditional high-speed stability peak.

scholarly journals Incremental, Critical Plane Analysis of Standing Wave Development, Self-Heating, and Fatigue during Regulatory High-Speed Tire Testing Protocols

2020 ◽  
Author(s):  
William V. Mars ◽  
Govind Paudel ◽  
Jesse D. Suter ◽  
Christopher G. Robertson
Keyword(s):  
Steady State ◽  
High Speed ◽  
Structural Integrity ◽  
Loss Modulus ◽  
Standing Waves ◽  
Strength Properties ◽  
Critical Plane ◽  
The Road ◽  
Self Heating ◽  
On The Road

ABSTRACT Tire speed ratings derive from regulatory testing in which tire structural integrity is validated over a series of steps with successively increasing speed. For the FMVSS 139 high-speed standard, there are four half-hour duration speed steps at 80, 140, 150, and 160 kph. Speed ratings from Q through Y may be attained through the UN ECE R30 regulation high-speed testing. For either protocol, a tire must demonstrate the ability to operate without crack development at high speed for a specified period. After the test, “there shall be no evidence of tread, sidewall, ply, cord, inner liner, belt or bead separation, chunking, broken cords, cracking, or open splices.” A workflow for simulating regulatory high-speed durability performance has been developed based upon (1) recent improvements to the Abaqus steady-state transport formulation that now permit converged solutions to be obtained at high speed (including after the development of standing waves in the tire) and (2) Endurica DT self-heating and incremental fatigue simulations that account for thermal effects and for damage accumulation occurring due to a schedule of load cases. The self-heating calculation features the Kraus model and accurately captures viscoelastic loss modulus dependence on strain amplitude and temperature. For each step of the high-speed procedure, steady-state structural and thermal solutions are first computed. The deformation history in the presence of standing waves is shown to require rainflow counting due to the occurrence of multiple load cycles per tire revolution. Crack growth is finally integrated for each potential critical plane through each step of the test until failure is indicated. Standing waves at high speed induce significant self-heating and damage, rapidly limiting high-speed performance. The temperature dependence of self-heating and strength properties also plays a major role in limiting high-speed durability. The simulations were executed on both a flat surface and on the regulation specified 1.7 m diameter road wheel. As expected, durability testing on the road wheel is more severe, and the beneficial effect of a nylon overwrap is predicted.

The Dynamic Analysis of High-Speed Energy Storage Flywheel Rotor System

2013 ◽  
Vol 770 ◽  
pp. 78-83
Author(s):  
Xiu Hua Zhang ◽  
Guang Xi Li ◽  
Long Nie
Keyword(s):  
Steady State ◽  
Energy Storage ◽  
High Speed ◽  
Transient Analysis ◽  
Critical Speed ◽  
Large Scale ◽  
Simulation Analysis ◽  
Rotor System ◽  
Analysis Method ◽  
Flywheel Rotor

This article aims at large-scale energy storage flywheel rotor system, obtaining the dynamic characteristics. Through theoretical analysis, and after doing a simulation analysis for a given flywheel rotor on the 0-20000 RPM, getting the flywheel rotor critical speed, the transient analysis and imbalance response. The system is in steady state at runtime according to the analysis results. Providing also certain theory basis for study of flywheel rotor system according to the analysis method .

Effects of Synchronous Vibration of Bearing on Stability of Externally Pressurized Air Journal Bearings

1999 ◽  
Vol 121 (4) ◽  
pp. 830-835 ◽  
Author(s):  
Jeong-Bae Lee ◽  
Kyung-Woong Kim
Keyword(s):  
Steady State ◽  
Phase Difference ◽  
High Speed ◽  
Control Algorithm ◽  
Journal Bearing ◽  
Stability Limit ◽  
Air Bearing ◽  
Synchronous Motion ◽  
Maximum Stability ◽  
The Stability

An active control of bearing is proposed as a new method to improve the stability characteristics of the externally pressurized air journal bearing and the results of numerical investigations of the stability characteristics of the actively controlled air journal bearing are presented. The synchronous control, where the bearing center whirls with the same frequency as the journal center with respect to the position in the steady state, is proposed as a control algorithm of the active air bearing. The step jump method is used to calculate the locus of the journal center which whirls or vibrates relative to the whirling bearing. The stability characteristics of the high speed rotor supported by actively controlled bearing system for zero steady-state eccentricity are investigated for various phase difference between the bearing and journal. It is shown that the stability of the air bearing can be greatly increased by the controlled synchronous motion of the bearing, and there is an optimum phase difference, which gives the maximum stability limit of the system.

scholarly journals Improving The Manoeuvrability of Electric Vehicle with Four-Wheel Drive and Four-Wheel Steering – A Nonlinear Model Vehicle Dynamics Approach

2018 ◽  
Vol 225 ◽  
pp. 05016
Author(s):  
M.I. Ishak ◽  
P.M. Heerwan ◽  
M.A.H. Rasid
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Electric Vehicle ◽  
Nonlinear Model ◽  
Rotational Speed ◽  
Vehicle Dynamics ◽  
High Speed ◽  
Passive Control ◽  
Vehicle Speed ◽  
Linear And Nonlinear

The dynamics motion of a vehicle is inherently a nonlinear dynamics system especially at high speed. Majority of past researches on four-wheel steering (4WS) vehicle adopt easier way of modelling a control system based on vehicle with linear dynamic equation of motion. This paper study on the vehicle dynamics of an electric vehicle with 4WD and 4WS based on nonlinear vehicle dynamic approach. A numerical simulation was performed to analyse the variance of a linear model and nonlinear model during cornering at various constant speed. The results show that during low speed cornering at 10 km/h, the linear and nonlinear model produced similar steady state cornering based on the trajectory and yaw rotational speed. However, the variants of linear and nonlinear started to appear as the vehicle speed increase. By obtaining the steady state cornering speed, another numerical simulation was performed to analyse the characteristics of the 4WD and 4WS electric vehicle. A passive control of the rear wheels’ steer angle was implement in the simulation. The results show that the parallel steering mode decreased the yaw rotational speed which broaden the trajectory of the cornering, while the opposite steering mode increased the yaw rotational speed that led to a tighter trajectory during cornering.

scholarly journals Influence Mechanism of Electromechanical Parameters on Transient Dynamics of FWD-EVs: Part I: Co-Modeling of IWM and Vehicle System

2021 ◽  
Vol 2101 (1) ◽  
pp. 012012
Author(s):  
Zhe Li ◽  
Qin Ba ◽  
Yang Ou ◽  
Yi Wang ◽  
Zhichao Zhao ◽  
...  
Keyword(s):  
High Speed ◽  
The Body ◽  
Influence Mechanism ◽  
Vehicle System ◽  
Wheel Drive ◽  
Fourier Series Method ◽  
Ev Model ◽  
Vibration Coupling ◽  
Four Wheel Drive ◽  
Speed Adjustment

Abstract In-wheel motor (IWM), as an ideal power source of independent four-wheel drive electric vehicles, has been paid more and more attention due to its high-power density, low starting current, wide speed adjustment range, simple control system and robustness. However, the electromechanical issue is enlarged in both longitudinal and vertical because of in-wheel driven scheme. In this paper, the electromagnetic multi-field characteristic of IWM is investigated based on Fourier series method. The negative vibration coupling on vehicle dynamics is discussed by proposing a conjoint electromechanical FWD-EV model. Results shows that the motor incentive coupled with the vehicle system in multi-degree of freedom, caused the body and wheel resonance in the low speed, meanwhile deteriorated the anti-rollover capability of the IWM-EV in the high speed.

Research on Crack of Cylinder Bracket Based on Numerical Simulation and Finite Element Analysis

2014 ◽  
Vol 940 ◽  
pp. 236-240
Author(s):  
Hong Fei Luo ◽  
Jian Cheng Wang ◽  
Jie Lei ◽  
Qing Bin Cui
Keyword(s):  
Numerical Simulation ◽  
Finite Element Analysis ◽  
Finite Element ◽  
High Speed ◽  
Simulation Analysis ◽  
Dynamics Simulation ◽  
Element Analysis ◽  
Gas Source ◽  
Simulation Based ◽  
Type Test

During type test experiment of loading mechanism, there exist a problem of deformation and cracking, in order to solve this problem, movement of cylinder under the action of gas source is analyzed by numerical simulation, based on this, use finite element analysis to execute dynamics simulation analysis, the effect of high-speed collisions when loading mechanism work it bring to cylinder bracket is analyzed, and the reason of cylinder bracket crack is find out. The modify method is put forward, it is proved by experiment that, after modify, the working reliability is significantly improved.

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