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Effects of Active Aerodynamic Wings on Handling Performance of High-Speed Vehicles

Univ. of Ontario Institute of Technology-Jingdong Cai, Saurabh Kapoor, Tushita Sikder, Yuping He
Published 2017-03-28 by SAE International in United States
In this research, active aerodynamic wings are investigated using numerical simulation in order to improve vehicle handling performance under emergency scenarios, such as tight cornering maneuvers at high speeds. Air foils are selected and analyzed to determine the basic geometric features of aerodynamic wings. Built upon the airfoil analysis, the 3-D aerodynamic wing model is developed. Then, the virtual aerodynamic wings are assembled with the 3-D vehicle model. The resulting 3-D geometry model is used for aerodynamic analysis based on numerical simulation using a computational fluid dynamics (CFD) software package. The CFD-based simulation data and the vehicle dynamic model generated are combined to study the effects of active aerodynamic wings on handling performance of high-speed vehicles. The systematic numerical simulation method and achieved results may provide design guidance for the development of active aerodynamic wings for high-speed road vehicles.
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Model Reference Adaptive Control for Active Trailer Steering of Articulated Heavy Vehicles

Univ. of Ontario Institute of Technology-Qiushi Wang, Shenjin Zhu, Yuping He
Published 2015-04-14 by SAE International in United States
This paper proposes a model reference adaptive control (MRAC) strategy for active trailer steering (ATS) in order to improve the lateral stability of articulated heavy vehicles (AHVs). Optimal controllers based on the Linear Quadratic Regulator (LQR) technique have been explored to enhance the lateral stability of AHVs; these controllers are designed under the assumption that the vehicle model parameters and operating conditions are given and they remain as constants. However, in reality, the vehicle system parameters and operating conditions may vary. To address the variable payloads of trailer(s), the controller based on MRAC technique is adopted. A three degrees of freedom (DOF) linear yaw-plane tractor-semitrailer model is generated to design the control law. The reference model is also developed using the linear yaw-plane model with the LQR technique. The effectiveness of the MRAC controller is demonstrated using numerical simulations under an emulated single lane-change maneuver.
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Phase-Plane Analysis for Evaluating the Lateral Stability of Articulated Vehicles

Univ. of Ontario Institute of Technology-Tao Sun, Yuping He
Published 2015-04-14 by SAE International in United States
The phase-plane analysis technique has become a powerful tool for analyzing lateral stability of single-unit vehicles. Articulated vehicles, such as car-trailer combinations, consist of multiple vehicle units. Multi-unit vehicles exhibit unique dynamic features compared against single-unit vehicles. For example, a car-trailer may exhibit one of the three unstable motion modes, i.e., jack-knifing, trailer sway and rollover. Considering the distinguished configurations and dynamic features of articulated vehicles, it is questionable whether the phase-plane analysis method based on single-unit vehicles is applicable for analyzing the lateral stability of multi-unit vehicles. In order to address the problem, case studies are conducted to test the effectiveness of the phase-plane method for analyzing the lateral stability of a car-trailer combination, which is represented by a nonlinear vehicle model generated using the CarSim software package. The phase-plane analysis, which examines the relation between the leading unit's side-slip angle and side-slip angular velocity (β − dβ/dt), the relation between the trailing unit's side-slip angle and side-slip angular velocity (β′ − dβ′/dt), and the interrelation of the side-slip angle of the leading unit,…
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Dynamics Analysis of Car-Trailer Systems with Active Trailer Differential Braking Strategies

SAE International Journal of Passenger Cars - Mechanical Systems

Univ. of Ontario Institute of Technology-Tao Sun, Yuping He, Jing Ren
  • Journal Article
  • 2014-01-0143
Published 2014-04-01 by SAE International in United States
To date, various control strategies based on linear vehicle models have been researched and developed for improving lateral stability of car-trailer (CT) systems. Is a linear-model-based controller applicable to active safety systems for CT systems under emergency operating conditions, such as an evasive maneuver at high lateral accelerations? In order to answer the question, the applicability of an active trailer differential braking (ATDB) controller designed using a linear CT model is tested and evaluated, while the controller being applied to a CT system represented by a linear and a nonlinear CT model. The current research leads to the following insightful findings: the ATDB controller designed using the linear model can effectively improve the lateral stability of CT systems under regular evasive maneuvers at low lateral accelerations, but the controller is not applicable to CT active safety systems under emergency evasive maneuvers at high lateral accelerations. The insightful findings resulted from the paper will provide valuable design guidelines for the development of active safety systems for CT systems.
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Design of an Actively Controlled Aerodynamic Wing to Increase High-Speed Vehicle Safety

Univ. of Ontario Institute of Technology-Yuping He
Published 2013-04-08 by SAE International in United States
This paper presents the design of airfoil and briefly introduces a real physical prototype for an actively controlled wing to improve high speed vehicle safety. Conventionally, active safety systems of road vehicles, including active steering and differential braking, mainly manipulate the tire/road forces to enhance the lateral stability of vehicles. However, this active safety technology is hindered by the saturation of tire/road forces at high lateral accelerations and on icy slippery roads. In contrast, the use of controlled aerodynamic forces has received little attention. In this paper, the actively controlled wing is proposed to manipulate the negative lift force (downforce) to enhance handling capabilities of vehicles at high speeds. Various wings are examined in terms of airfoil shapes, coefficient of drag and lift, resulting yaw/roll moments, effect of wing attack angle at different Reynolds numbers using numerical simulations with X-Foil, Gambit and Fluent software packages. A prototype of the proposed actively controlled wing is briefly introduced. The essential design parameters, functionality and features of the active wing are addressed. In a companion paper that will…
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Design and Evaluation of Active Trailer Steering Systems of Long Combination Vehicles Using Driver-Software-in-the-Loop Simulations

Univ. of Ontario Institute of Technology-Xuejun Ding, Yuping He
Published 2012-04-16 by SAE International in United States
Vehicle simulators are often used for vehicle system development and driver behaviour study. The target of this study is to design and evaluate an Active Trailer Steering (ATS) system for a Long Combination Vehicle (LCV) with mutiple trailers using a real-time vehicle simulator. A linear yaw-plane LCV model is generated to derive an optimal ATS controller. Then, the controller is reconstructed in LabVIEW and integrated with a vehicle model for a B-train double from TruckSim. The Driver-Software-in-the-Loop (DSIL) real-time simulations are conducted with the vehicle simulator. The DSIL real-time simulations indicate that the ATS controller can effectively improve the LCV's low-speed maneuverability and high-speed stability under the test maneuvers of a low-speed 90-degree turn and a high-speed single-lane change, respectively. The investigation based on the DSIL real-time simulations paves the road to the future development of electronic control units (ECUs) for the ATS system using Driver-Hardware-in-the-Loop real-time simulations.
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Numerical Simulation and Analysis of Closed-Loop Driver/Articulated Vehicle Dynamic Systems

SAE International Journal of Commercial Vehicles

Univ. of Ontario Institute of Technology-Xuejun Ding, Yuping He
  • Journal Article
  • 2012-01-0244
Published 2012-04-16 by SAE International in United States
This paper presents a preliminary investigation of the closed-loop driver/articulated vehicle directional dynamics using numerical simulation. To date, a lot of attention has been focused on investigating the closed-loop directional dynamics of driver/single-unit vehicle systems. Little effort has been paid to examining the closed-loop directional dynamics of driver/articulated vehicle systems. Compared with single-unit passenger cars, multi-unit articulated vehicles have unique directional dynamic characteristics. Generally, a driver's behavior for an articulated vehicle is different from that for a passenger car. To investigate the impact of driver behavior on articulated vehicle directional dynamics, three driver models based on dynamic responses of tractor, trailer and combined tractor/trailer, respectively, have been developed. The three driver models are tested and compared through the numerical simulations of a low-speed path-following and a high-speed lateral stability test maneuvers for a driver/articulated vehicle system. The numerical studies are conducted in a Simulink-TruckSim simulation environment in such a way that the driver model is designed using Simulink from Matlab software, and the articulated vehicle model is constructed in TurckSim multibody dynamic package, then, the…
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Well-To-Wheel Energy Use and Greenhouse Gas Emissions Analysis of Hypothetical Fleet of Electrified Vehicles in Canada and the U.S.

Univ. of Ontario Institute of Technology-Miguelangel Maduro, Greg Rohrauer
Published 2011-04-12 by SAE International in United States
The objective of this study is to determine the energy use and Greenhouse Gas (GHG) emissions involved in adopting various electrified vehicle technologies over the next decade in Canada and the United States. The vehicle architectures selected for this work stem from those in the EcoCAR competitions. Each architecture was simulated using Argonne National Laboratory's (ANL) Powertrain System Analysis Toolkit (PSAT) software to determine the energy consumption and petroleum use. Natural Resources Canada's GHGenius model and ANL's GREET model were employed to determine the upstream emissions resulting from each region's power generation mix. Results from each powertrain and fuel combination were analyzed in order to understand the repercussions of introducing these vehicle technologies over the next decade. The three Canadian Provinces selected for this study were Alberta, Ontario, and Quebec. The U.S. regions studied were the Northeastern U.S., California, and the complete U.S. mix. Regions were selected due to their contrasting power generation schemes. This paper describes the implications and the impact of various vehicle technology mixes in each region for the year 2020.
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An Optimal Preview Controller for Active Trailer Steering Systems of Articulated Heavy Vehicles

Univ. of Ontario Institute of Technology-Md Manjurul Islam , Yuping He
Published 2011-04-12 by SAE International in United States
An optimal preview controller is designed for active trailer steering (ATS) systems to improve high-speed stability of articulated heavy vehicles (AHVs). AHVs' unstable motion modes, including jack-knifing and rollover, are the leading course of highway accidents. To prevent these unstable motion modes, the optimal controller, namely the compound lateral position deviation preview (CLPDP) controller, is proposed to control the steering of the front and rear axle wheels of the trailing unit of a truck/full-trailer combination. The corrective steering angle of the trailer front axle wheels is determined using the preview information of the lateral position deviation of the trajectory of the axle center from that of the truck front axle center. In turn, the steering angle of the trailer rear axle wheels is calculated considering the lateral position deviation of the trajectory of the axle center from that of the trailer front axle. To evaluate the vehicle performance measure, a driver model is introduced and it ‘derives’ the vehicle model based on well-defined testing specifications. The linear quadratic regular (LQR) technique is applied to the…
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An Integrated Design Method for Articulated Heavy Vehicles with Active Trailer Steering Systems

SAE International Journal of Passenger Cars - Mechanical Systems

Univ. of Ontario Institute of Technology-Yuping He, Md Manjurul Islam
Genist Systems Company-Timothy D. Webster
  • Journal Article
  • 2010-01-0092
Published 2010-04-12 by SAE International in United States
This paper presents an integrated design method for active trailer steering (ATS) systems of articulated heavy vehicles (AHVs). Of all contradictory design goals of AHVs, two of them, i.e. path-following at low speeds and lateral stability at high speeds, may be the most fundamental and important, which have been bothering vehicle designers and researchers. To tackle this problem, a new design synthesis approach is proposed: with design optimization techniques, the active design variables of ATS systems and passive design variables of trailers can be optimized simultaneously; the ATS controller derived from this approach has two operational modes, one for improving lateral stability at high speeds and the other for enhancing path-following at low speeds. To demonstrate the effectiveness of the proposed approach, it is applied to the design of an ATS system for an AHV with a tractor and a full trailer. Simulation results illustrate that compared with the baseline vehicle, the one derived from the design synthesis approach decreases low-speed off-tracking by 35.2% and reduces high-speed rearward amplification ratio by 30.0%. The proposed approach…
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