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In this paper, we propose a model for eco-driving that considers cornering effects. The proposed model purely relies on the geometric configuration of the vehicle and road. Consequently, we propose an eco-driving optimal control problem formulation that is suitable for both straight and curved trajectories in urban scenarios. Moreover, it can be applied for vehicles with front wheel drive (FWD) or rear wheel drive (RWD). We use a case study for an electric vehicle executing cornering maneuvers to validate the proposed approach and highlight its advantages with respect to traditional eco-driving formulations. Results show an approximated improvement of 8% in energy savings with respect to traditional eco-driving strategies, especially in trajectories with large curvatures.

Modern motorcycles are evolving more and more towards complex systems by the increasing integration of mechanical, electrical and control disciplines. All-wheel drive (AWD) vehicles have proven effective to improve vehicle's performances and rider's safety. Despite this, manufacturers have developed few AWD motorcycles and little research has been devoted to them. Obvious difficulties concern torque distribution to the front wheel because of steering system. Nowadays, the integration of technologies eases the implementation of front wheel drive opening new research perspectives. In this work, the dynamic model of an AWD motorcycle with an attached rider is proposed. It represents the first symbolic analysis investigating the effects of front wheel traction on the dynamics of a motorcycle for supporting the design of AWD motorcycles reducing trials and tests on prototypes. The proposed model is parametric with respect to the motorcycle geometry, and it allows to simulate complex operating modes of the AWD, such as cornering phenomena, taking into account coupling of lateral and longitudinal dynamics and tire-road interactions. Unlike other works, here the authors include a full tire model by exploiting theoretical slips of the brush model for tire's aligning moment too, instead of applying a totally empirical representation less suitable for a complete symbolic description. Besides, to simulate the equations of motion, the benefits and disadvantages of using AWD with torque distribution have been pointed out introducing a new handling ratio. Two verification procedures validate the model: one is performed theoretically, the other carries out a comparison with a multibody software, whose model is more sophisticated, this latter embeds all main motorcycle's dynamics. Although radically different, being the first theoretical and the second numerical-computational, both methods exhibit consistent behavior between them, and effectiveness of the former is also consistent with the results of a multibody simulator under the assumptions made.

International audience; The present manuscript deals with experimental investigations on thermal effects of air leakage zones at the boundaries of the vehicle hood. Measurements are carried out on a Peugeot 207 (Front Wheel Drive) in wind tunnel. The front wheels are activated by the car's engine and rolling on controlling rollers built in the wind tunnel. In parallel, the wind velocity is well controlled in order to simulate real conditions of driving. The underhood compartment is equipped with 80 thermocouples distributed on different components. Three operating conditions are studied according to the engine's rpm, to the wind and wheels velocities. The leakage zones are purposely clogged with five different configurations. The effect of the leakage zones has shown significant impact on the temperature field and has been physically analyzed.

Made available in DSpace on 2018-12-11T17:33:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01. Added 1 bitstream(s) on 2021-07-15T14:34:16Z : No. of bitstreams: 1 S0100-69162017000400699.pdf: 481340 bytes, checksum: fd53e16da4807f0f0bc4764d0035d989 (MD5) The mechanized gathering process of sweeping coffee is extremely important to reduce the losses of fruit not used in the harvesting operation. But this operation usually has a low operational performance and a high cost per unit collected in this way any measures that can effectively reduce costs increase the viability of the operation. In this sense, studies on adequacy tractor mass for each operation show improvement in energy use, reducing fuel consumption. So, this study aimed to quantify the fuel consumption and effective power along the process of a tractor 4x2 FWD pulling the coffee harvester. I was used as treatments three ballasting settings, these being equivalent the relations power to weight of 36, 39 and 42 kg hp-1 working with and without activated FWD, randomized statistically, with 10 repetitions each configuration. It was conclude that, at low power-weight ratio, the front wheel drive assist had no significant influence on the hour fuel consumption. Already in the configuration with higher ratio, the use of front wheel drive favored in reducing fuel consumption and better energy use. São Paulo State University (Unesp) School of Agricultural and Veterinarian Sciences Federal University of São Carlos São Paulo State University (Unesp) School of Agricultural and Veterinarian Sciences

The handling behaviour of vehicles is an important property for its relation to performance and safety. In 1970s, Pacejka did the groundwork for an objective analysis introducing the handling diagram and the understeer coefficient. In more recent years, the understeer concept is still mentioned but the handling is actively managed by direct yaw control (DYC). In this paper an accurate analysis of the vehicle handling is carried out, considering also the effect of drive forces. This analysis brings to a new formulation of the understeer coefficient, which is almost equivalent to the classical one, but it can be obtained by quasi-steady-state manoeuvres. In addition, it relates the vehicle yaw torque to the understeer coefficient, filling up the gap between the classical handling approach and DYC. A multibody model of a Formula SAE car is then used to perform quasi-steady-state simulations in order to verify the effectiveness of the new formulation. Some vehicle set-ups and wheel drive arrangements ...

This article presents a new dynamic motion stabilization approach to front-wheel drive in-wheel motor electric vehicles. The approach includes functions such as traction control system, electronic differential system, and electronic stability control. The presented electric vehicle was endowed with anti-skid performance in longitudinal accelerated start; smooth turning with less tire scrubbing; and safe driving experience in two-dimensional steering. The analysis of the presented system is given in numerical derivations. For practical verifications, this article employed a hands-on electric vehicle named Corsa-electric vehicle to carry out the tests. The presented approach contains an integrated scheme which can achieve the mentioned functions in a single microprocessor. The experimental results demonstrated the effectiveness and feasibility of the presented methodology.

The aim of this paper is to investigate the optimality of the handbrake cornering technique for a Front Wheel Drive vehicle. Nonlinear Optimal Control theory is used to formulate the problem of optimal cornering and to simulate manoeuvres used by race drivers. Handbrake cornering is optimal with an appropriate selection of the minimization cost. The optimal solution is validated against data collected during the execution of the technique by an expert race driver on a loose off-road surface. Further optimization results considering high adhesion road surface are obtained to show that the optimality of the technique is not affected by the road conditions.

An analytical model to simulate the traction performance of mechanical front wheel drive MFWD tractors was developed at the Agroscope Reckenholz-Tänikon ART. The model was validated via several field tests in which the relationship between drawbar pull and slip was measured for four MFWD tractors of power ranging between 40 and 123 kW on four arable soils of different texture (clay, clay loam, silty loam, and loamy sand). The pulling tests were carried out in steady-state controlling the pulling force along numerous corridors. Different configurations of tractors were considered by changing the wheel load and the tyre pressure. Simulations of traction performance matched experimental results with good agreement (mean error of 8% with maximum and minimum values of 17% and 1% respectively). The model was used as framework for developing a new module for the excel application TASCV3.0.xlsm, a practical computer tool which compares different tractor configurations, soil textures and conditions, in order to determine variants which make for better traction performance, this resulting in saving fuel and time, i.e. reducing the costs of tillage management.