Speed Cornering Research Articles

Computational fluid dynamics analysis for an active rear-wing design to improve cornering speed for a high-performance car

The aim of the study is to numerically analyze the active rear wing and select the optimum combination of an airfoil(s) to improve the cornering speed of a Mustang GT 2017 high-performance car. Rear wings are used in sports cars to create downforce and more traction without increasing the car weight to keep it stable on the ground during turns and to prevent slipping and rolling. Using the concept of Lateral Load Transfer (LLT), the downforce required to stabilize the vehicle's unbalance while cornering at selected speeds was calculated. The NACA 6412 airfoil was chosen due to its high coefficient of lift with respect to the angle of attack and thus can generate more downforce. Further, a CFD (Computational Fluid Dynamics) analysis has been performed using Ansys Fluent to estimate the coefficient of lift for selected airfoil combinations in an active and passive state. The viscous SST k-Omega solver has been used in simulation with different angles of attack and chord lengths of the airfoil. On comparing the results, the optimum combination of an airfoil(s) was selected to increase the cornering speed sufficiently.

Conflict and Sensitivity Analysis of Articulated Vehicle Lateral Stability Based on Single-Track Model

Lateral stability is quite essential for the vehicle. For the vehicle with an articulated steering system, the vehicle load and steering system performance is quite different from the passenger car with the Ackman steering system. To investigate the influence of the tire characteristics and vehicle parameters on lateral stability, a single-track dynamic model is established based on the vehicle dynamic theory. The accuracy of the built model is validated by the field test result. The investigated parameters include the tire cornering stiffness, vehicle load, wheelbase, and speed. Based on the snaking steering maneuver, the lateral stability criteria including the yaw rate, vehicle sideslip angle, tire sideslip angle, and lateral force are calculated and compared. The sensitivity analysis of the tire and vehicle parameters on the lateral stability indicators is initiated. The results demonstrated that the parameters that affect the lateral vehicle stability the most are the load on the rear part and the tire cornering stiffness. The findings also lay a foundation for the optimization of the vehicle’s lateral stability.

Design and Development of Roll Cage and Steering System of Go-Kart

Go-kart is a one of the motor sport which is played globally. This racing does not require any professional drivers or greater speed. It is a light weight and cheaper vehicle which does not require suspension and differential. In this paper we are concentrating on Roll cage and steering system of Go-kart. While keeping it light weight, chassis material is selected as AISI 1018 which give more tensile strength, machinability, and can sustain maximum load. For designing and analysis CATIA and ANSYS soft wares were used. Whereas in steering system the Ackermann steering mechanism is used for attaining maximum cornering speed, without the slippage of tires. This also gives us minimum turning radius, helping us to take sharp turns when the driver has to take sharp corners.

Advanced Vehicle Control With an Optimized Speed Profile Using Road Characteristics for Road Departure Prevention

Many passenger vehicles are equipped with automatic safety features. One system, Electronic Stability Control (ESC), saved 7,024 lives from 2011 to 2015. While effective, ESC and other similar control systems are reactionary in nature and require knowledge of a vehicle's current state to determine the response at the next state. Also, many control systems do not take the road characteristics into account, despite being an important contributor to a vehicle's dynamics. This work presents a predictive vehicle controller to help prevent roadside departures during cornering that incorporates the road's geometry and roughness to estimate the vehicle's safe operating speed. An Optimized Speed Profile generates a speed trajectory to allow the vehicle to successfully navigate the corner while preserving ride quality. Simulation results demonstrate cases in which vehicles equipped with ESC would depart from the road while the proposed system does not. Simulations demonstrate that road roughness effects account for up to 10% of the velocity changes in the maximum allowable cornering speed; simulations based on a real-world highway off-ramp measurement demonstrate that the proposed control system is capable of lane-keeping while maintaining stability.

Energy Management of Hybrid Electric Vehicle Using Vehicle Lateral Dynamic in Velocity Prediction

Accurately predicting the changes in the speed has a significant impact on the quality of the energy management in hybrid vehicles. Many methods for predicting the speed have been proposed in the literature, but few fully consider vehicle dynamics to predict speed changes. To this end, a new method is introduced to predict the vehicle speed and to perform energy management for hybrid vehicles in situations where lateral dynamics plays a significant role. Based on the tire–road friction coefficient and the GPS signal, the maximum cornering speed of the vehicle, in which each tire force does not saturate, is evaluated. Then, the principle of using less friction braking and using more regenerative braking, the vehicle speed prediction controller is designed. In the end, an optimal control method with a new equivalent factor (EF) adaptive algorithm is designed to distribute the torque of the engine and the motor, as well as the shift schedule of the gearbox. A driver-in-the-loop experiment is used to prove that the vehicle installed with the proposed speed prediction controller has an average 29.1% increase in energy efficiency compared to vehicle that do not have speed prediction controller. And, the EF adaptive algorithm keeps the battery SoC at a reasonable interval.

A new methodology to optimize a race car for inertial sports

In sports competitions with wheeled vehicles, the resistances to movement that most affect vehicle performance are aerodynamic drag, rolling resistance, inertial forces and gravitational forces. When a powerful engine is available, the rolling resistance is negligible but, in competitions where the vehicle has a low-power engine or lack of it, the rolling resistance has a significant influence on the vehicle performance. The resistance to advance in curve due to the steer angle (curve resistance) is not taken into account during the design process. However, as noted in other research for this type of vehicle, the curve resistance cannot be neglected. Therefore, this article develops a methodology to optimize the vehicle cornering behavior of non-motored vehicles intended for inertial sports, which can be applied to any type of wheeled vehicle. The target of the vehicle optimization is to maximize its cornering speed, while its resistance to movement is reduced. As will be shown, both factors are related and opposed to each other.

Aerodynamic optimisation of Formula student vehicle using computational fluid dynamics

This work aims to improve the external aerodynamic characteristics of the 2017 University of Huddersfield Formula SAE vehicle. To improve dynamic performance in the SAE events, a multiple-element rear wing was developed, which incorporated adjustable elements to constitute a drag reduction system (DRS). A numerical modelling approach was adopted to produce a suitable design. A simplified model of the vehicle was created to obtain baseline coefficients of lift (CL) and drag (CD). The rear wing was optimised to find the peak configuration generating maximum downforce. The results show that the incorporated rear wing improved the vehicle’s CL from 0.21 acting in the positive Y axis (lift) to 1.15 acting in the negative Y axis (downforce), whereas the CD increased from 0.71 to 1.21. However, the DRS configuration reduced the CD to 0.79. Using the obtained lift and drag coefficients, vehicle performance was estimated, such as maximum cornering speed, straight-line top speed and straight-line acceleration capabilities. The rear wing improved the theoretical maximum cornering speed by 3.1% for a corner radius of 13 m. The DRS increased the theoretical top speed by 18.2% compared to a fixed wing configuration. Acceleration potential increased by 15.7% at 25 m/s with the DRS open. The final section of the study used an online simulator (FSAESim) to make predictions of the acceleration event time, which were compared to the track results from the 2017 Hungary SAE event. The results showed a 97% similarity.

高速旋回時の安心感と車体スリップ角特性との関係 －ドライバモデルに基づく解析とDS 実験による検証－

高速旋回時の安心感と車体スリップ角特性との関係 －ドライバモデルに基づく解析とDS 実験による検証－

低速旋回時の目標車両運動 : ヨーレート・車体スリップ角の定常ゲインの関係考察

低速旋回時の目標車両運動 : ヨーレート・車体スリップ角の定常ゲインの関係考察

Reducing the cornering resistance by torque vectoring

Usually, torque vectoring is used to reduce a significant understeer behavior at high speed cornering. Thus, providing larger vehicles with a sportive touch. Even on typical front wheel driven cars torque vectoring control is available now. Torque vectoring is nearly a standard on electric driven vehicles. Complex control and optimization strategies are applied to improve the maneuverability in particular or to enhance the driving behavior and reduce the energy consumption in addition. This paper shows, that a quite simple strategy will enhance the maneuverability and simultaneously reduce the cornering resistance in sharp bends. At first, a case study with a fully non-linear and three-dimensional vehicle model is performed. It turned out that a full drive torque shift to the outer wheels improves the maneuverability and reduces the cornering resistance in addition. This results are verified by an optimization performed with a simpler four-wheeled handling model. Here, the front steering angles and the driving torques at each of the four wheels are considered as free parameters. Minimizing the cornering resistance by taking the equations of motion for the four-wheeled handling model as constraints will deliver an optimal set of parameters then.

Kinematic corner smoothing for high speed machine tools

This paper presents a novel kinematic corner smoothing technique for high-speed CNC machine tools. Typically, reference tool-paths compromised of short G01 moves are geometrically smoothed by means of arcs and splines within the NC system. In this study, a continuous feed motion is generated by directly planning jerk limited velocity transitions for the drives in the vicinity of sharp corners of the tool-path. This approach completely eliminates the need for geometry based path smoothing and feed planning. Contouring errors at sharp corners are controlled analytically by accurately calculating cornering speed and duration. Since proposed approach bases on kinematically planning axis motion profiles, it exploits acceleration and jerk limits of the drives and delivers a near-time optimal motion. Experimental validation and comparisons are presented to show significant improvement in the cycle time and accuracy of contouring Cartesian tool-paths.

Linear Quadratic Optimal Regulator for Steady State Drifting of Rear Wheel Drive Vehicle

<div class=""abs_img""> <img src=""[disp_template_path]/JRM/abst-image/00270003/01.jpg"" width=""340"" />Single-track vehicle drifting</div> Drifting is a large sideslip cornering technique with counter steering, which is advantageous in some driving conditions where vehicle-handling capability over linear tire slip-friction characteristics is imperative. In this paper, the dynamics of a rear-wheel-drive (RWD) vehicle cornering at steady states was simplified using a single-track vehicle model. In addition, tire frictions in any slip conditions were estimated from the combination of the Pacejka's magic formula and the modified Nicolas-Comstock tire model. A computer program was developed, on the basis of the equations of motion (EOMs) derived via the body-fixed coordinate so that the suitable cornering speed and its corresponding steady-state driving control inputs (the steering angle and rear wheel slip ratio) could be calculated automatically for any given radius of curvature and vehicle sideslip. The other set of EOMs was derived via the normal-tangential coordinate and then linearized so that the state space description could be constructed. Eventually, the linear quadratic optimal regulator was designed and simulated via MATLAB for various regulation problems where the initial condition of each individual state deviated from its desired steady-state value. According to the simulation results, the physical explanation of the control inputs can be used as guidance for adjusting vehicle behavior in manual driving.

Integrated Chassis Control for Enhancement of High Speed Cornering Performance

Integrated Chassis Control for Enhancement of High Speed Cornering Performance

High speed cornering strategy with confined contour error and vibration suppression for CNC machine tools

This paper presents a novel real-time trajectory generation algorithm for accurate high-speed cornering applications. Typically, reference tool-paths compromised of G01 lines are geometrically smoothed by means of arcs and splines. In this study, a kinematic corner smoothing algorithm approach is proposed where the cornering trajectory of the tool is generated through FIR (Finite Impulse Response) filtering of discontinuous axis velocity commands at segment junctions. Contouring errors at sharp corners are controlled analytically by optimally overlapping acceleration profiles of previous and present segments. Residual vibrations due to excitation of structural modes are avoided by tuning filter delays for all drives. The proposed method has been experimentally demonstrated to show significant improvement in the cycle time and accuracy of contouring Cartesian tool-paths.

Electric Cultivator Design and its Impact of the Operator

Small type gasoline engine has the advantage of lightweight and low energy, but its emissions of carbon dioxide will lead to global greenhouse gas growing. This study aims to test the performance of the cultivator between different soil and tools. Comparative test electric and gasoline engine type cultivator contains the following items: energy consumption, carbon dioxide emissions in the job and the operator heart rate change. The results show that the width of 60 cm and depth of 3 cm operating conditions weeding, electric cultivators and gasoline engine cultivator average turn time was 2.9 seconds and 3.3 seconds, with an average forward speed were 0.535 and 0.515 m/s. Comparison of the time and forward speed cornering, the electric cultivator superior gasoline engine cultivator, and can successfully achieve high torque output characteristics weeding needed. Energy consumption and carbon emissions test data show that the loam fields, the average power consumption cost of NT $ 21.2/ha; carbon dioxide emissions by an average of 26 kg/ha. This result shows that energy consumption in the consideration of the performance of carbon dioxide emissions, electric cultivators have lower costs. The test results are displayed in the field; the electric cultivator operator heart rate is lower than the gasoline engine cultivator and has significant difference statistically. Therefore, in the field of long-term operating conditions, the electric cultivator helps reduce physical exertion and operator fatigue.

Fuzzy sliding mode control algorithm for a four-wheel skid steer vehicle

This research design and implement a robust dynamic feedback controller for a four-wheel skid steering vehicle (SSV) under high- speed cornering motion. First, SSV dynamics are modeled and analyzed to construct the simulation environment and to validate the per- formance of the proposed algorithm. A robust fuzzy-sliding mode controller is then designed to offset the effect of forces induced by wheel—soil interaction during skidding and ground-level fluctuations. It also eliminates the chattering phenomena encountered with conventional sliding mode control. Given P-3AT mobile robot parameters for trajectory tracking and velocity setting, extensive simula- tion results demonstrate the effectiveness of the proposed controller.

ADVANCED CONTROL SYSTEMS IN TWO WHEELER AND FINDING THE COLLISION SITE OF THE VEHICLE USING GSM

In the earlier days, vehicles such as Motorbikes hardly had Mechanical support in all concerns, in the recent past the development in Electronic devices in Motorbikes are evolving, with components such as E-breaks, Digital speedometers, etc. and most interesting from an engineering point of view, dealing with motorcycle dynamics is more complex than it is for four wheeled vehicles. In fourwheeled vehicles, electronic stability control (ESC) was introduced in the recent past to improve passengers’ safety in critical driving conditions and it is now part of most commercial cars. For two-wheeled vehicles, the design of such a control system is an open problem, and it constitutes quite a challenging task due to the complexity of two-wheeled vehicles dynamics and to the strong interaction between the vehicle and the driver, so to encourage this scheme I am Designing an advanced electronic active stability control system with ABS assistance for e-bikes providing the much needed vehicle roll stability control in situations such as high speed cornering etc. Designing a system that, in any case of emergency situation such as crashing, will send the bicycle accident location to nearby hospitals/emergency services with the assistance of GSM

Design and Modeling of Trailer Battery Energy Storage for Range Extension of Electric Vehicles

Automotive manufacturers have in the last few years put on the market new models of electric vehicles (EV) such as the Nissan Leaf and Tesla Roadster, demonstrating their awareness to the upcoming fossil/renewable energy transition. While the infrastructure around EVs is yet to be developed completely in most countries, potential buyers are being attracted by the idea of driving a vehicle which could save money by only using electricity as a source of energy. By extension, having a portable modular device in the form of a trailer attached to a vehicle and fitted with extra energy storage would allow current EVs to be used beyond their usual range limits, as well as provide space for carrying extra gear. This paper focuses on the electrical modeling and design of a battery pack tted inside the trailer and a range estimation is calculated over a standardized driving cycle, using the high level programming language, Octave. A lithium based chemistry was chosen for numerical application, real data were used and case studies are presented to illustrate how the internal hardware of the trailer affects its performance. A value of 150 km of extra range was set as a target for the design, from which other trailer characteristics can be derived such as the weight distribution within the trailer and the maximum cornering speed. Overall, this work can be used as a preliminary design tool, able to accommodate different design options using the mathematical model employed.

Влияние параметров управляемой пневматической подвески на устойчивость автотранспортного средства

Installation of controlled air suspension system on the vehicle is suggested, carrying low-density cargo, such as timber or pipe, which reduces risk of tipping of the vehicle when cornering at high speeds and small radii, and will increase the speed cornering, and therefore the performance of the vehicle. In the case of train we propose control device which at the beginning of the rotation of the steering wheel while entering the turn, reduces the stiffness of the suspension of tractor-trailer wheel on the internal side.

Optimal Control for Steady State Drifting of RWD Vehicle

Drifting is a cornering technique with large angle of sideslip, which might be useful in some cornering conditions when full handling capacity over the linear region of the wheel slip-tire friction characteristic is imperative. In this work, steady state cornering of a RWD vehicle on plane, with constant speed, sideslip and radius of curvature, was simplified via the single track vehicle model. In addition, BNP magic formula, along with MNC tire model, was used to estimate tire frictions. The computer program was developed, based on EOMs derived via body fixed coordinate, in order to calculate a suitable cornering speed and corresponding open-loop driving control inputs, consisting of steering angle and rear slip ratio, for a given radius of curvature and vehicle sideslip. The other set of EOMs, in terms of vehicle states and driving control inputs, was derived refer to n-t coordinate; also, linearized so that the state space description could be constructed. Eventually, LQR stabilizing controller had been designed and simulated via MATLAB. According to the results of simulation, any state deviation could be regulated to the desired steady state. The development of automatic drifting assistant may be feasible in the very near future.