Should a Vehicle Always Deviate to the Tire Blowout Side? - A New Tire Blowout Model with Toe Angle Effects

Author(s):  
Ao Li ◽  
Yan Chen ◽  
Xinyu Du ◽  
Wen-Chiao Lin

Abstract As a severe tire failure, tire blowout during driving can significantly threaten vehicle stability and road safety. Tire blowout models were developed in the literature to conclude that a vehicle always deviates to the tire blowout side. However, this conclusion is proved to be inaccurate in this paper, since one important factor was largely ignored in the existing tire blowout models. Toe angle, as a basic and widely-applied setup on ground vehicles, can provide preset and symmetric lateral tire forces for normal driving. However, when tire blowout occurs, different toe angle setups can impact vehicle motions in different ways. For the first time, the toe angle is explicitly considered and integrated into a tire blowout model in this paper. For different tire blowout locations, driving maneuvers, and drivetrain configurations, the impacts of different toe angle setups on the variations of tire friction forces and vehicle motions are analyzed. The developed tire blowout model with toe angles is validated through both high-fidelity CarSim® simulation results and experimental results of a scaled test vehicle. Both simulation and experimental results show that a vehicle may not deviate to the tire blowout side, depending on the toe angle setups and driving maneuvers. Moreover, the experimental results also validate that the proposed tire blowout model can accurately evaluate the tire blowout impacts on vehicle dynamics.

Author(s):  
Shuo Cheng ◽  
Ming-ming Mei ◽  
Xu Ran ◽  
Liang Li ◽  
Lin Zhao

Knowledge of the tire-road information is not only very crucial in many active safety applications but also significant for self-driving cars. The tire-road information mainly consists of tire-road friction coefficient and road-tire friction forces. However, precise measurement of tire-road friction coefficient and tire forces requires expensive equipment. Therefore, the monitoring of tire-road information utilizing either accurate models or improved estimation algorithms is essential. Considering easy availability and good economy, this paper proposes a novel adaptive unified monitoring system (AUMS) to simultaneously observe the tire-road friction coefficient and tire forces, i.e., vertical, longitudinal, and lateral tire forces. First, the vertical tire forces can be calculated considering vehicle body roll and load transfer. The longitudinal and lateral tire forces are estimated by an adaptive unified sliding mode observer (AUSMO). Then, the road-tire friction coefficient is observed through the designed mode-switch observer (MSO). The designed MSO contains two modes: when the vehicle is under driving or brake, a slip slope method (SSM) is used, and a recursive least-squares (RLS) identification method is utilized in the SSM; when the vehicle is under steering, a comprehensive friction estimation method is adopted. The performance of the proposed AUMS is verified by both the matlab/simulinkCarSim co-simulation and the real car experiment. The results demonstrate the effectiveness of the proposed AUMS to provide accurate monitoring of tire-road information.


2010 ◽  
Vol 38 (3) ◽  
pp. 182-193 ◽  
Author(s):  
Gary E. McKay

Abstract When evaluating aircraft brake control system performance, it is difficult to overstate the importance of understanding dynamic tire forces—especially those related to tire friction behavior. As important as they are, however, these dynamic tire forces cannot be easily or reliably measured. To fill this need, an analytical approach has been developed to determine instantaneous tire forces during aircraft landing, braking and taxi operations. The approach involves using aircraft instrumentation data to determine forces (other than tire forces), moments, and accelerations acting on the aircraft. Inserting these values into the aircraft’s six degree-of-freedom equations-of-motion allows solution for the tire forces. While there are significant challenges associated with this approach, results to date have exceeded expectations in terms of fidelity, consistency, and data scatter. The results show excellent correlation to tests conducted in a tire test laboratory. And, while the results generally follow accepted tire friction theories, there are noteworthy differences.


1977 ◽  
Vol 5 (2) ◽  
pp. 75-82 ◽  
Author(s):  
A. Schallamach

Abstract Expressions are derived for side force and self-aligning torque of a simple tire model on wet roads with velocity-dependent friction. The results agree qualitatively with experimental results at moderate speeds. In particular, the theory correctly predicts that the self-aligning torque can become negative under easily realizable circumstances. The slip angle at which the torque reverses sign should increase with the normal load.


Actuators ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 122
Author(s):  
Dejun Yin ◽  
Junjie Wang ◽  
Jinjian Du ◽  
Gang Chen ◽  
Jia-Sheng Hu

Torque distribution control is a key technique for four-wheel independent-drive electric vehicles because it significantly affects vehicle stability and handling performance, especially under extreme driving conditions. This paper, which focuses on the global yaw moment generated by both the longitudinal and the lateral tire forces, proposes a new distribution control to allocate driving torques to four-wheel motors. The proposed objective function not only minimizes the longitudinal tire usage, but also make increased use of each tire to generate yaw moment and achieve a quicker yaw response. By analysis and a comparison with prior torque distribution control, the proposed control approach is shown to have better control performance in hardware-in-the-loop simulations.


1976 ◽  
Vol 49 (3) ◽  
pp. 862-908 ◽  
Author(s):  
K. A. Grosch ◽  
A. Schallamach

Abstract Evidence accumulates that tire forces on wet roads, particularly when the wheel is locked, are determined by the dry frictional properties of the rubber on the one hand and by hydrodynamic lubrication in the contact area on the other. The probable reason why they are so clearly separable is that water is a poor lubricant, tending to separate into globules and dry areas under relatively small pressures. Road surfaces and tire profiles are, therefore, designed to create easy drainage and high local contact pressures. The influence of road friction on vehicle control well below the critical conditions is becoming more clearly understood; but more Investigations are required here, in particular under dynamic conditions.


Author(s):  
William H. Robinson

Robinson Seismic's latest developments in seismic isolation includes a new device, the RoballTM, for seismically isolating structures during earthquakes. This advance is a new concept for seismic isolation based on the principle of the inverted pendulum. It consists of 'friction balls' or 'Roballs' moving between upper and lower spherical like cavities or flat plates. The Roballs are filled with a material which is able to provide the friction forces required to absorb the energy from numerous earthquakes while supporting the structure. The Roball technique is expected to enable light and in the future possibly heavy structures to be more economically seismically isolated. As part of a program to develop a user friendly 'seismic isolation system' a series of full-scale tests have been carried out on a number of possible designs including three approaches for vertical pressures of -1 MPa resulting in coefficients of friction of -0.1 to -0.4. In this paper we present the preliminary experimental results.


1988 ◽  
Vol 110 (1) ◽  
pp. 62-69 ◽  
Author(s):  
M. Tomizuka ◽  
R. Horowitz ◽  
G. Anwar ◽  
Y. L. Jia

This paper is concerned with the digital implementation and experimental evaluation of two adaptive controllers for robotic manipulators. The first is a continuous time model reference adaptive controller, and the second is a discrete time adaptive controller. The primary purpose of these adaptive controllers is to compensate for inertial variations due to changes in configuration and payload, as well as disturbances, such as Coulomb friction and/or gravitational forces. Experimental results are obtained from a laboratory test stand, which emulates an one-axis direct drive robot arm with variable inertia, as well as a Toshiba TSR-500V industrial robot. Experimental results from the test stand indicate that these adaptive control schemes are promising for the control of direct drive robot arms. Friction forces arising from the harmonic gear of the Toshiba robot were detrimental if not properly compensated. Because of a high gearing ratio, the advantage of adaptive control for the Toshiba arm could be shown only by detuning the controller.


Author(s):  
Jin-Jang Liou ◽  
Grodrue Huang ◽  
Wensyang Hsu

Abstract A variable pressure damper (VPD) is used here to adjusted the friction force on the valve spring to investigate the relation between the friction force and the valve bouncing phenomenon. The friction force on the valve spring is found experimentally, and the corresponding friction coefficient is also determined. Dynamic valve displacements at different speeds with different friction forces are calibrated. Bouncing and floating of the valve are observed when the camshaft reaches high speed. From the measured valve displacement, the VPD is shown to have significant improvement in reducing valve bouncing distance and eliminating floating. However, experimental results indicate that the valve bouncing can not be eliminated completely when the camshaft speed is at 2985 rpm.


2017 ◽  
Vol 26 (10) ◽  
pp. 1750066
Author(s):  
Kosim Olimov ◽  
K. G. Gulamov ◽  
Khusniddin K. Olimov ◽  
Sagdulla L. Lutpullaev ◽  
Vladimir V. Lugovoy ◽  
...  

The partial inelasticity coefficients of baryon fragments of oxygen nuclei and pions were investigated and the full inelasticity coefficient was determined for the first time in [Formula: see text] collisions at [Formula: see text]. The fraction of kinetic energy of incident proton in [Formula: see text] collisions at [Formula: see text] spent on formation of all the baryon fragments and production of charged and neutral pions was found. The experimental results were compared with those obtained in other experiments at high energies. The experimental full inelasticity coefficient in [Formula: see text] collisions at [Formula: see text] was reproduced well by calculations within the framework of Glauber model of multiple scatterings in hadron–nucleus collisions.


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