Tire Non-Uniformities And Steering Wheel Vibrations

2005 ◽  
Vol 33 (2) ◽  
pp. 64-102 ◽  
Author(s):  
H. R. Dorfi

Abstract Steering wheel vibrations are frequently related to non-uniformities of the tire/wheel system. While steering system design is a major factor in the sensitivity of the vehicle, the excitation of steering wheel vibrations is due in general to non-uniformities of the tire/wheel system. However, tire non-uniformities are to some extent unavoidable and result in rolling force variation at the spindle during steady state rolling. Therefore, limiting and managing these non-uniformities is of great economic importance to tire manufacturers. The present work demonstrates the tire's role in generating non-uniformity induced dynamic force variations due to 1st order geometric imperfections. Both analytical and numerical approaches are studied. Numerical experiments of the effects of non-uniformities are investigated with the physics based tire model FTIRE. The effects of tire resonance on the non-uniformity force amplitudes are demonstrated through modeling and simulation. The model is then verified using experimental data and the distribution of geometric non-uniformities is studied in a large tire sample based on force measurement data and the model fit. A MSC.ADAMS model of a light truck is combined with non-uniform FTIRE models to study the effect of geometric non-uniformities on steering wheel vibrations. The simulations show that the angular acceleration of the steering wheel around its steer-axis is primarily dependent on force variations in the longitudinal direction (T1H). The effects of phasing, increase in inertia and tire position on the steering wheel vibrations are also discussed.

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 118
Author(s):  
M. Kobusch ◽  
L. Klaus

This paper presents experimental investigations of in-situ dynamic force calibrations in which an impact hammer provides the dynamic reference force. Here, the force transducer to be calibrated remains in the original mechanical structure of the force measurement application to which calibration shock forces are applied in a suitable way. Numerous experiments with different force transducer set-ups and different impact hammer configurations were conducted to validate this in- situ calibration method. The paper describes the analysis of the measurement data and presents the force transfer functions obtained. Finally, these dynamic calibration results are discussed.


Author(s):  
U Neureder

Many studies of mechanisms contributing to steering wheel nibble have been carried out in the past. This paper deals with some aspects that have not yet been studied, or those that have been presented by several authors but are deemed to be controversial. Firstly, an overview of stimulation sources (disturbance factors), and the significance these have with respect to steering nibble, is given. As an example of the controversial aspects of the problem, this paper deals with the assumption of dry friction in steering gear models and its conflict with the observed transfer of vibration caused by small (realistic) amounts of imbalance or tyre force variation. After modelling the steering gear resistance correctly, it is possible to identify, in the steering gear, a natural frequency that contributes reasonably to the nibble phenomenon. Based on this new model, a CAE study on parameter sensitivity, using the ‘design of experiments’ approach, is presented.


2021 ◽  
Vol 62 (7) ◽  
Author(s):  
Marie Tanno ◽  
Hideyuki Tanno

Abstract A multi-component aerodynamic test for an airframe-engine integrated scramjet vehicle model was conducted in the free-piston shock tunnel HIEST. A free-flight force measurement technique was applied to the scramjet vehicle model named MoDKI. A new method using multiple piezoelectric accelerometers was developed based on overdetermined system analysis. Its unique features are the following: (1) The accelerometer’s mounting location can be more flexible. (2) The measurement precision is predicted to be improved by increasing the number of accelerometers. (3) The angular acceleration can be obtained with single-axis translational accelerometers instead of gyroscopes. (4) Through the averaging process of the multiple accelerometers, model natural vibration is expected to be mitigated. With eight model-onboard single-axis accelerometers, the three-component aerodynamic coefficients (Drag, Lift, and Pitching moment) of MoDKI were successfully measured at the angle of attack from 0.7 to 3.4 degrees under a Mach 8 free-stream test flow condition. A linear regression fitting revealed a 95% prediction interval as the measurement precision of each aerodynamic coefficient. Graphical abstract


Author(s):  
Eeshan Ranade

Automobile industry’s focus is on efficiency, safety and performance has resulted in the rapid introduction of electronics in vehicle safety systems and engine management. Mechanical and Hydraulic systems are now gradually being replaced by electronic controllers to achieve the objectives of optimizing power consumption, improving driver convenience, and maximizing driver safety resulting in an overall improved performance and experience. Vehicle steering systems have transitioned from mechanical to hydraulic power to an electric power assisted steering system and now to the state of the art, Steer by Wire (SbW) system. Traditional mechanical systems included a steering wheel, column, gear, rack and pinion and did not support any power steering. The next generation hydraulic systems were more stable, safer and required comparatively lesser effort. Electric or DC motors drove the Electric Power System addressing the drawbacks of the hydraulic systems especially those related to environment and acoustics with the added advantage of a compact structure and power-on-demand engine performance. By-wire steering technologies was originally introduced in the Concord aircraft in 1970s. The SbW is a steering system with no steering column. The mechanical interface between the steering wheel and the wheels is replaced with by-wire electrical connection/electronic actuators. SbW system has significant advantages in terms of driving safety due to the availability of the steering command in electronic form and the removal of the steering shaft, cruising comfort with driving manoeuvring due to no space constraint and favourable to the environment with the non-usage of hydraulic oils.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhaojian Wang ◽  
Hamid Reza Karimi

We focus on the antivibration controller design problem for electrical power steering (EPS) systems. The EPS system has significant advantages over the traditional hydraulic steering system. However, the improper motor controller design would lead to the steering wheel vibration. Therefore, it is necessary to investigate the antivibration control strategy. For the implementation study, we also present the motor driver design and the software design which is used to monitor the sensors and the control signal. Based on the investigation on the regular assistant algorithm, we summarize the difficulties and problems encountered by the regular algorithm. After that, in order to improve the performance of antivibration and the human-like steering feeling, we propose a new assistant strategy for the EPS. The experiment results of the bench test illustrate the effectiveness and flexibility of the proposed control strategy. Compared with the regular controller, the proposed antivibration control reduces the vibration of the steering wheel a lot.


2014 ◽  
Vol 602-605 ◽  
pp. 316-319
Author(s):  
Shao Song Wan ◽  
Jian Cao ◽  
Cong Yan

In present work, the distribution of electric field strength on the surface of work piece was analyzed through ANSYS and theoretical equation. Moreover, the attractive force acting on particles that disperses in ER polishing fluid was calculated. A series of basic experiments were conducted, it is aimed to find out the effective process parameters on the surface roughness using the work piece as electrode. Vehicle handling directional stability has been more and more important, experiments for steering wheel corner step input response, steering oil tank response property, steady state turning and steering angle of all steering wheels were conducted in this paper, the experimental results show that multi-wheel steering system can fulfill its function very well and reach target angle, it provides a new method for researching for the vehicle handling directional stability.


2010 ◽  
Vol 439-440 ◽  
pp. 1393-1397
Author(s):  
Xiao Hong Yue ◽  
Yong Jian Mao ◽  
Hao Pu ◽  
Bao Liang Niu ◽  
Lei Wang ◽  
...  

The technique of centrifuge model test has been widely used in geotechnical mechanics and engineering because of its low cost and low test scale. In order to investigate the dynamic behaviors of the geotechnical model under explosion, we are developing an explosion geotechnical centrifuge. The dynamic environment of explosion is necessary to be determined for the strength design of the centrifuge nacelle. This paper presents the dynamic force measurement of the model container to the centrifuge nacelle under a typical explosion. Firstly, three cylindrical supports were designed and calibrated by quasi-static compressive tests. The force-strain relations are measured and linearly fitted. Secondly, an explosion test was performed and the dynamic strain histories of the supports were measured. Then the dynamic force histories were obtained combined with the calibration results. The investigation provides an understanding of the dynamic environment for the centrifuge nacelle design.


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