Model-Based Approach for Cornering Stiffness and Yaw Moment of Inertia Estimation of a Scaled Electric Vehicle

2020 ◽  
Author(s):  
Alexandre M. Ribeiro ◽  
André R. Fioravanti ◽  
Ely C. de Paiva

This paper addresses the problem of estimating the tire cornering stiffness coecient and the yaw moment of inertia of a scaled car-like vehicle. The method merges measurements information of the vehicle lateral response along with its nonlinear planar model. Aiming effective and accurate results, we propose solving an optimization problem based on a representative dataset obtained experimentally using a persistently exciting input. The validation of the proposed method is shown by comparing the agreement between numerical simulations, evaluated with the estimated parameters, with experimental data. Three representative maneuvers are considered for this purpose, including indoor and outdoor experiments.

Author(s):  
Federico Cheli ◽  
Stefano Melzi ◽  
Edoardo Sabbioni ◽  
Michele Vignati

In recent years the interest towards electric vehicles has increased. Among the different layout of the electric powertrain, four in-wheel motors appear to be one of the most attractive. This configuration in fact allows to re-design inner spaces of the vehicle and presents, as an embedded feature, the possibility of independently distributed braking and driving torques on the wheels in order to generate a yaw moment able to improve vehicle handling (torque vectoring). The present paper presents and compares two different torque vectoring control strategies for an electric vehicle with four in-wheel motors. Performances of the control strategies are evaluated by means of numerical simulations of open and closed loop maneuvers, also taking into account their energetic efficiency.


Author(s):  
Larissa Steiger de Freitas ◽  
Marcus Vinícius Canhoto Alves ◽  
Rafael Rodrigues Francisco

Author(s):  
Fakhreddine Landolsi ◽  
Fathi H. Ghorbel ◽  
James B. Dabney

AFM-based nanomanipulation is very challenging because of the complex mechanics in tip-sample interactions and the limitations in AFM visual sensing capabilities. In the present paper, we investigate the modeling of AFM-based nanomanipulation emphasizing the effects of the relevant interactions at the nanoscale. The major contribution of the present work is the use of a combined DMT-JKR interaction model in order to describe the complete collision process between the AFM tip and the sample. The coupling between the interactions and the friction at the nanoscale is emphasized. The efficacy of the proposed model to reproduce experimental data is demonstrated via numerical simulations.


2021 ◽  
pp. 204141962110377
Author(s):  
Yaniv Vayig ◽  
Zvi Rosenberg

A large number of 3D numerical simulations were performed in order to follow the trajectory changes of rigid CRH3 ogive-nosed projectiles, impacting semi-infinite metallic targets at various obliquities. These trajectory changes are shown to be related to the threshold ricochet angles of the projectile/target pairs. These threshold angles are the impact obliquities where the projectiles end up moving in a path parallel to the target’s face. They were found to depend on a non-dimensional entity which is equal to the ratio between the target’s resistance to penetration and the dynamic pressure exerted by the projectile upon impact. Good agreement was obtained by comparing simulation results for these trajectory changes with experimental data from several published works. In addition, numerically-based relations were derived for the penetration depths of these ogive-nosed projectiles at oblique impacts, which are shown to agree with the simulation results.


2013 ◽  
Vol 658 ◽  
pp. 602-608 ◽  
Author(s):  
Cheng Lin ◽  
Chun Lei Peng

This paper presents the design of mixed H∞/H2Output Feedback Controller for Independent Drive Electric Vehicle Stability Control. It generates yaw moment by applying driving intervention at front Independent driving wheels according to the vehicle states. The performance of the proposed controller is evaluated through a series of simulations under different velocity and different mass. The simulation results show that the controller can help vehicle against a certain range of uncertainty (speeds and loads) and get excellent robust performance.


Author(s):  
Stephanie Follett ◽  
Amer Hameed ◽  
S. Darina ◽  
John G. Hetherington

In order to validate the numerical procedure, the explosion of a mine was recreated within the non-linear dynamics software, AUTODYN. Two models were created and analysed for the purposes of this study — buried and flush HE charge in sand. The explosion parameters — time of arrival, maximum overpressure and specific impulse were recorded at two stand-off distances above the ground surface. These parameters are then compared with LS-DYNA models and published experimental data. The results, presented in table format, are in reasonable agreement.


2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Andrea Rapisarda ◽  
Alessio Desando ◽  
Elena Campagnoli ◽  
Roberto Taurino

The design of modern aircrafts propulsion systems is strongly influenced by the important objective of environmental impact reduction. Through a great number of researches carried out in the last decades, significant improvements have been obtained in terms of lower fuel consumption and pollutant emission. Experimental tests are a necessary step to achieve new solutions that are more efficient than the current designs, even if during the preliminary design phase, a valid alternative to expensive experimental tests is the implementation of numerical models. The processing power of modern computers allows indeed the simulation of more complex and detailed phenomena than the past years. The present work focuses on the implementation of a numerical model for rotating stepped labyrinth seals installed in low-pressure turbines. These components are widely employed in sealing turbomachinery to reduce the leakage flow between rotating components. The numerical simulations were performed by using computational fluid dynamics (CFD) methodology, focusing on the leakage performances at different rotating speeds and inlet preswirl ratios. Investigations on velocity profiles into seal cavities were also carried out. To begin with, a smooth labyrinth seal model was validated by using the experimental data found in the literature. The numerical simulations were extended to the honeycomb labyrinth seals, with the validation performed on the velocity profiles. Then, the effects of two geometrical parameters, the rounded fin tip leading edge, and the step position were numerically investigated for both smooth and honeycomb labyrinth seals. The obtained results are generally in good agreement with the experimental data. The main effect found when the fin tip leading edge was rounded was a large increase in leakage flow, while the step position contribution to the flow path behavior is nonmonotone.


2016 ◽  
Vol 66 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Michal Šofer ◽  
Rostislav Fajkoš ◽  
Radim Halama

AbstractThe main aim of the presented paper is to show how heat treatment, in our case the induction hardening, will affect the wear rates as well as the ratcheting evolution process beneath the contact surface in the field of line rolling contact. Used wear model is based on shear band cracking mechanism [1] and non-linear kinematic and isotropic hardening rule of Chaboche and Lemaitre. The entire numerical simulations have been realized in the C# programming language. Results from numerical simulations are subsequently compared with experimental data.


Author(s):  
Byamakesh Nayak ◽  
Sangeeta Sahu ◽  
Tanmoy Roy Choudhury

<p>This paper explains an adaptive method for estimation of unknown parameters of transfer function model of any system for finding the parameters. The transfer function of the model with unknown model parameters is considered as the adaptive model whose values are adapted with the experimental data. The minimization of error between the experimental data and the output of the adaptive model have been realised by choosing objective function based on different error criterions. Nelder-Mead optimisation Method is used for adaption algorithm. To prove the method robustness and for students learning, the simple system of separately excited dc motor is considered in this paper. The experimental data of speed response and corresponding current response are taken and transfer function parameters of  dc motors are adapted based on Nelder-Mead optimisation to match with the experimental data. The effectiveness of estimated parameters with different objective functions are compared and validated with machine specification parameters.</p>


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