Browse Topic: All wheel drive

Items (277)
Continuing its rollout of EVs, Cadillac revealed the 2025 Optiq SUV, the company's most affordable EV yet and a smaller sibling to the popular Lyriq that was introduced last year. With a company-estimated range of 300 miles (482 km), the Optiq comes standard with dual-motor AWD, three years of Super Cruise hands-free driving, and what Cadillac officials say is segment-best cargo capacity and second-row space
Clonts, Chris
This document seeks to classify all-wheel drive (AWD) architectures primarily based on the installed hardware and does not consider the implementation of the controls and software. For example, a power transfer unit (PTU) may be equipped with a clutch that is capable of torque management, but the control implementation only uses it for disconnection functions without torque management. In this SAE Recommended Practice, attention will be given to passenger cars and light trucks (through Class III). The definitions presented herein may also be applicable to heavy trucks (Class 4 through 8) and off-highway applications using more than two axles but are primarily focused on passenger cars and light trucks
Drivetrain Standards Committee
This paper presents the characteristics of more than 260 trim levels for over 50 production electric vehicle (EV) models on the market since 2014. Data analysis shows a clear trend of all-wheel-drive (AWD) powertrains being increasingly offered on the market from original equipment manufacturers (OEMs). The latest data from the U.S. Environmental Protection Agency (EPA) shows that AWD EVs have seen a nearly 4 times increase in production from 21 models in 2020 to 79 models in 2023. Meanwhile single axle front-wheel-drive (FWD) and rear-wheel-drive (RWD) drivetrains have seen small to moderate increases over the same period, going from 9 to 11 models and from 5 to 12 models, respectively. Further looking into AWD architectures demonstrates dual electric machine (EM) powertrains using different EM types on each axle remain a small portion of the dual-motor AWD category. However, these architectures have been shown to have energy savings of 1 % to 5 % over that of identical dual-motor
Allca-Pekarovic, AlexanderKollmeyer, PhillipMiddleton, MairiEmadi, Ali
The proliferation of electric vehicles (EVs) is resulting in a big transition in the automotive industry, with the goal of reducing greenhouse gas emissions and improving energy efficiency. There are a variety of different architectural configurations and power distribution strategies that can be optimized for drivability performance, all-electric range, and overall efficiency. This paper describes the efforts of the research team in exploring different EV architectures to better understand their impacts on system performance in terms of energy efficiency and vehicle drivability. In search for an ideal powertrain architecture for a shared-use EV, the research team conducted a comprehensive analysis of a various EV architectures (including RWD and AWD) with different motor parameters, considering a spectrum of targeted vehicle technology specifications such as acceleration and braking performance, and fuel economy. To quantify these performance indices, a model-based design approach was
Oswald, DavidEscobar, JacquelineWu, GuoyuanJung, HeejungBarth, Matthew
The test vehicle is All Wheel Drive (AWD) vehicle which is powered by four-cylinder engine. The power is transferred from the powertrain to the wheel through power transfer unit (PTU), propeller shaft, flexible rubber coupling and Integrated Rear Differential Assembly (IRDA) . Higher boom noise and vibration levels are observed when driving the vehicle in 4th gear WOT conditions. NVH levels are dominant between 1150 rpm to 2100 rpm and at 2200 rpm in 2nd order and 4th order respectively. Operational deflection shape (ODS) analysis is carried out on entire vehicle to identify the location where maximum deflection is observed at the problematic frequency. It is identified that higher torsional excitation from the powertrain is exciting the IRDA pitching mode and the propeller shaft bending mode which is the reason for higher 2nd order and 4th order NVH levels. The driveline forces are entering the body through the IRDA and rear cradle bushes. The dynamic stiffness of IRDA bushes is
S, Nataraja MoorthyRao, ManchiRaghavendran, Prasath
Honda knows what U.S. buyers like: crossovers. So it makes perfect sense that the company chose a crossover SUV configuration for its first “mainstream” U.S.-market EV, the 2024 Prologue. The company's not postulating about how many Prologues it might sell annually once its new EV, co-developed with GM, goes on sale in early 2024. But Honda sold more than 350,000 CR-V crossovers in 2022, which left little doubt Honda wasn't going to take any chances regarding the bodystyle for its first North American mass-market EV. The Prologue's smooth and rounded sheetmetal is pleasant but cautious (Honda calls it “neo-rugged”) - and like many current EVs from volume automakers such as Hyundai (Ioniq 5) and Volkswagen (ID.4), it's lowish-roof profile stretches the definition of “SUV,” or even crossover. At an overall height of 64.7 in. (1643 mm), the 2024 Prologue seems noticeably lower, for example, than an all-wheel-drive CR-V's height of 66.5 in. (1689 mm
Visnic, Bill
This document will apply to the most common applications of electric motors, used for activating all-wheel drive (AWD) and four-wheel drive (4WD) disconnect systems as used in passenger (car and light truck) vehicles. The standard will provide consistent definition, terminology, tests, and reporting methods
Drivetrain Standards Committee
The Tractors are inevitable in the world due to its remarkable contribution majorly in farming process and other applications. the farming equipment needs to perform multiple applications to enhance the productivity and increased horsepower demands all-wheel drive (Refer fig. 1) or four-wheel drive option in the tractor. So, it is becoming a mandatory feature. The main objective of this study is, improving the torsional fatigue life in front axle spindle shaft by modifying the spline design and optimizing induction hardening heat treatment process in such a way that the other part of the system will have a minor or no design change. It helps us to reduce the part count variability, lower manufacturing cost and development time. The spindle shaft with undercut design and profile modified design were subjected to tortional fatigue test with same loading conditions to understand the fatigue life cycle difference between two designs at the load of 700kgm as per DVP, the current spline
Gunalan, Magendran
This paper describes idle vibration reduction methods using a Stellantis vehicle as a case study. The causes of idle vibration are investigated using the NVH source, path, and receiver method. The torque transfer path into a vehicle has shown to be very important in determining vehicle idle vibration response. New electronic control enablers that affect idle vibration are tested and discussed, including Neutral Idle Control (NIC), Transfer-case Idle Control (TIC,®), and Switchable Engine Mounts (SEM). The Design For Six Sigma (DFSS) analysis method is used to arrive at an optimized result for vehicle idle vibration. This paper also discusses the results confirming TIC’s capability of reducing idle vibration on all-wheel drive vehicles. Transfer-case Idle Control is a new idle vibration control enabler developed by Stellantis and a patent was awarded by the United State Patent and Trademark Office
Yuan, WeiNakkash, GaryRoco, RobOrzechowski, JeffBowen, BrookeSanders, Mark
The Ferrari Purosangue scurries up the snowbound pitches of Italy's Monte Bondone, the Alpine peak whose auto-hillclimb exploits date to 1925. Ferrari's first “SUV” - really, more a genre-blurring crossover - slices through Bondone's 38 devilish corners, gaining nearly 4,900 ft (1,494 m) of elevation over an 11.2-mile (18-km) workout. Its 715-hp (533-kW) V12 sings like the tragically-fated opera hero it is, to an 8,250-rpm height that's as lofty as the surrounding Dolomites. Emissions regulations may soon spell the end of that barrel-chested, 6.5-L engine, whose 12 naturally-aspirated cylinders describe every roadgoing Ferrari built between 1947 and 1973. But the rest is modern magic, the kind of prestidigitation that's required to transform a 4,774-lb (2165-kg), AWD machine - the first Ferrari with four doors and four adult-sized seats - into a stunning performer that feels lighter and lither than any driver would ever expect
Ulrich, Lawrence
This paper proposes DAS(Disconnect Actuator System), a system applied to an EV’s auxiliary driving system to decrease electric consumption. The proposed DAS functions to connect or disconnect the power of the EV AWD auxiliary driving system. Also, this system has a high driving performance of AWD. When only the main driving system is driven(2WD) to improve electric efficiency in EV AWD without DAS, electric efficiency is low due to drag loss generated by the rotation of internal mechanical elements in the auxiliary driving system. To reduce the drag loss of the auxiliary driving system and has the high driving performance of the AWD, A DAS that can connect or disconnect the power between the mechanical elements of the auxiliary driving system is essential. A system analysis was performed to determine the layout of the DAS, and DAS was developed using optimization by analyzing the factors related to the NVH(Noise Vibration Harshness) and seamless shifting. The method is called ‘Seamless
Yang, SedongShin, BongJooWoo, MoonsikAhn, Jongbaelee, SangheonKim, YeonhoJung, Jongmoon
This investigation focuses on conventional powertrain technologies that provide operational synergy based on customer utilization to reduce fuel consumption for a heavy-duty, nonroad (off-road) material handler. The vehicle of interest is a Pettibone Cary-Lift 204i, with a base weight of 50,000 lbs. and a lift capacity of 20,000 lbs. The conventional powertrain consists of a US Tier 4 Final diesel engine, a non-lockup torque converter, a four-speed powershift automatic transmission, and all-wheel drive. The paper will present a base vehicle energy/fuel consumption breakdown of propulsion, hydraulic and idle distribution based on a representative end-user drive cycle. The baseline vehicle test data was then used to develop a correlated lumped parameter model of the vehicle-powertrain-hydraulic system that can be used to explore technology integration that can reduce fuel consumption. Two conventional powertrain modifications are explored that provide potential pathways that
Goodenough, BryantCzarnecki, AlexanderRobinette, DarrellWorm, JeremyLatendresse, PhilWestman, John
Safety is considered one of the most important parameters when designing a ground vehicle. The adverse effect of weather on a vehicle can lead to a surge in safety issues and accidents. Several safety assistance systems are available in modern vehicles, which are designed to lessen the negative effects of weather hazards. Although these safety systems can intervene during crucial conditions to avoid accidents, driving a vehicle on snowy or icy terrain can still be a challenging task. Road conditions with the least tire-road friction often results in poor vehicle handling, and without any kind of safety system it can lead to mishaps. With the use of Adams Car software and vehicle dynamics modeling, a realistic relationship between the vehicle and road surface may be established. The simulation can be used to have a better understanding of vehicle handling in snowy and icy conditions, tire-ice interaction, and tire modeling. In this work a vehicle dynamics model is created using the
Tekade, Shantanu GajananSequeira, CristonBastiaan, Jennifer
Applications in commercial and military fields created high demands on the steering performance of multi-axle vehicle. With the characteristic of more degrees of freedom (DOF), all-wheel cooperative steering is more conducive to improve the steering performance of multi-axle vehicle. This paper studies multi-axle vehicle assembled with steer-by-wire system, and proposes a control strategy to achieve all-wheel cooperative steering to improve the low-speed steering flexibility and high-speed steering stability of multi-axle vehicle. Based on the ideal steering performance at low-speed and high-speed, the steady-state gain of multi-axle vehicles at different speeds is reshaped. Also, the corresponding vehicle reference model is constructed to provide the ideal vehicle state as a reference. The precision of the vehicle reference model is verified by an all-wheel independent steering platform. Accordingly, the state feedback control module which contains a sliding mode controller and a
Li, JiaqiLiu, YahuiXu, TaoQu, Pengshuai
An undeniable technical achievement since its U.S. launch for the 2001 model year, Toyota's Prius never has been able to shake its weenie-mobile reputation. It's an image formed largely by the combination off oddball, aerodynamics-first styling and the pursuit of ultimate fuel efficiency via low-power propulsion. With EVs looming as the propulsion endgame and attention to the 20th-century concept of “fuel-efficiency” waning, Toyota's said “enough!” The 2023 Prius bodywork now is smooth, low and sleek, so different that there's virtually no visual connection to its trippy forerunners. Under the hood is a larger, powered-up 4-cyl. engine and similarly boosted drive motor that, combined, take the Prius to 194 hp (196 hp for AWD models) - a 60% jump over the wheezy 121 combined hp of its predecessor. Almost paradoxically, though, the 2023 Prius still sips gasoline at pretty much the same pace - up to a 57 mpg (4.1L/100 km) combined rating for the most-efficient LE trim in front-wheel drive
Visnic, Bill
The effect of water in all-wheel-drive (AWD) clutch oil and on chatter noise due to negative μ-V gradient and inconsistent static friction coefficient was shown in this present study. First, the relationship between the front and rear axle speed delta and the steering angle of an on-demand AWD vehicle during turning was analyzed. After the comparison of the noise of the warranty-returned AWD clutch oil, the water content difference was observed and proven through statistical hypothesis testing. According to tribological studies, a negative μ-V gradient could cause stick-slip and lead to chatter noise. This hypothesis has been verified via a bench test established according to SAE #2 standard. The clutch pack consisted of multiple paper-based friction plates and carbon steel reaction plates, and different water contents in the oil were tested on the test bench. The result showed that differences in water content in the clutch oil could affect the clutch static friction coefficient, and
Wang, Hai
This paper investigates the effect of tire inflation pressure on the directional stability of All Wheel Drive (AWD) vehicles during high-speed off-road maneuvers over different soft terrains such as loam, sand and clay. For this purpose, a fourteen-degrees-of-freedom (14-DOF) full parametrized vehicle model is employed and numerically simulated in MATLAB/Simulink environment to represent the full vehicle body dynamics such as roll, yaw and pitch motions. In order to calculate tire forces and moments over deformable terrains, the AS2TM Soft Soil Tire Model was successfully integrated with the vehicle model which enabled the possibility of changing tire pressure and consequently investigate its effect on vehicle dynamics. Numerous simulations are carried out to examine vehicle handling in case of different tires inflation pressure during steady state turning maneuvers such as ramp steer input. Simulation results at both moderate and high-speed turning maneuvers showed that changing tire
Sharaf, Alhossein MostafaMohamed, Abdelrhman Ayman
Simplified vehicle dynamics models used to study the driveline durability are typically limited to the longitudinal dynamics and do not account for vertical and pitch dynamics. The influence of suspension on the vehicle ride and handling characteristics is studied extensively in the literature but its impact on the driveline torques is often not considered. In this paper, an effort is made to investigate the influence of suspension compliance on the driveline torque using a planar (longitudinal, pitch and vertical) vehicle dynamics model. An AWD vehicle is studied to understand its impact on the torque levels of both axles (primary and secondary). Subsequently the planar dynamics is explored in the context of anti-squat/anti-dive suspension. The primary focus of the paper is to predict the driveline torque. While more sophisticated suspension models are built and used to study the ride and handling characteristics of the vehicle, to the authors’ knowledge this is the first time, a
Sondkar, PrashantJammulamadaka, Anand
Passive hydrocarbon traps (“HCT”) are limited in performance when installed in an oxygen deprived location, such as an underfloor that is downstream of a CC TWC. An OEM 1.0L close-coupled converter in a 1.4L turbo hybrid PZEV calibrated vehicle was replaced with a 1.24L HC trap. The HC trap consisted of a zeolytic storage layer beneath a Pd/Rh containing three-way catalyst layer. The UF converter was upgraded with a newer TWC technology. The HC trap and UF TWC were engine aged to simulate 150,000 miles, or full useful life conditions. Criteria for accelerated engine aging of the HC trap were selected based on the vehicle application’s peak operating bed temperatures in the field. Vehicle FTP and US-06 tests were conducted on an all-wheel drive dyno which facilitated normal hybrid powertrain operation. A SULEV20 engineering target for FTP nMHC+NOx emissions was met with the full useful life aged CC HC Trap (“HCT”) system, using a PGM amount that was lower than the OEM design. The aged
Moser, David H.Nipunage, SanketNunan, JohnDay, RyanAlltizer, Chad
This SAE Recommended Practice covers power transfer units (PTUs) used in passenger car and sport utility vehicles to support all wheel drive (AWD) operation. PTUs are typically full-time use geared devices (see 3.1). Some PTUs have additional features such as part-time on-demand capability via electronically actuated disconnect features, and other configurations are possible
Drivetrain Standards Committee
All-wheel drive (AWD) and four-wheel drive (4WD) vehicles are becoming more prevalent in the market today. However, it is not well understood what the correct practice is when only one tire on the vehicle needs to be replaced. There are various recommendations and practices provided by tire dealers and car manufacturers to the consumer. The most common recommendation is to replace more than a single tire and match tread depths across all tires. The basis for this recommendation is the idea that tires with different tread depths will have a different number of revolutions per distance traveled due to differences in rolling radius. Mixing tires with different tread depths may cause extra wear or damage to the drivetrain components because, on a vehicle, the tires must rotate at different speeds to travel the same distance. In this study, the rolling radius of tires is measured on vehicle to understand the impact of tread depth, tire brand and model, and inflation pressure on the rolling
Kan, YuonHoffman, SethCarter, Tom
All-wheel Drive (AWD) is a mature technology and most automobile manufacturers offer this feature on their vehicles. Improved traction, enhanced vehicle stability, and better handling are some of the key characteristics of AWD vehicles which are achieved by distributing the appropriate level of torque to the front and rear axles. Accurately capturing the torque split between the two axles is essential for sizing of driveline components like gears, bearings, and shafts. Traditionally, the torque split is considered to be either 50-50%, or solely proportional to the static weight distribution between the two axles. Design decisions are made based on historical test data. In this paper a longitudinal vehicle dynamics model for AWD systems is proposed to understand the influence of various key factors such as dynamic weight transfer, compliance of driveline components, and changing tire radius on the torque split. Comparison with the test data is performed to understand the significance
Sondkar, PrashantGharpure, SwapneelSchrand, VinceAttibele, Pradeep
The refresh of the 2021 model-year Chrysler Pacifica minivan premiers a top-of-the-line luxury trim, the debut of a next-generation infotainment system, and the return of all-wheel-drive. Chrysler minivans haven't offered AWD since 2004, but the driveline choice is revived for the 2021 model. “We'll make AWD available in the current generation minivan for about 90 days, starting in the second quarter of 2020, to get it into the market,” Matt Davis, director of Chrysler and Fiat Brands for Fiat Chrysler Automobiles, said prior to the 2021 Pacifica's unveiling at the 2020 Chicago Auto Show
Buchholz, Kami
Electrification of the powertrain is one of the most promising trends in the automotive industry. Among the novel architectures, this paper aims to study the latent advantages provided by in-wheel motors, particularly an All-Wheel-Drive powertrain composed by four electric machines directly connected to each wheel-hub of a high performance vehicle. Beyond the well-known packaging advantage allowed by the in-wheel motor, the presence of four independent torque sources allows more flexible and complex control strategies of torque allocation. The study explores three different control modules working simultaneously: torque vectoring, regenerative braking and energy efficiency optimization protocol. The main objectives of the project are: improving handling, measured through the lap time of the virtual driver in a simulated track, and enhance energy efficiency, assessed by the battery state of charge variation during standard events. The torque vectoring strategy is based on a feedback PID
de Carvalho Pinheiro, H.Galanzino, E.Messana, A.Sisca, L.Ferraris, A.Airale, A. G.Carello, M.
This SAE Recommended Practice defines the various types of information required by the collision repair industry to properly restore light-duty, highway vehicles to their pre-accident condition. Procedures and specifications are defined for damage-related repairs to body, mechanical, electrical, steering, suspension, and safety systems. The distribution method and publication timeliness are also considered
Motor Vehicle Council
This SAE Recommended Practice covers transfer cases used in passenger car and light truck applications. Transfer cases are of the chain, geared, manually and electronically shifted types although other configurations are possible. The operating points (speeds, temperatures, etc.) were chosen to mirror those of the United States Environmental Protection Agency Vehicle Chassis Dynamometer Driving Schedules (DDS
Drivetrain Standards Committee
Fuel economy and performance are both important in the design of hybrid pickup trucks. All-wheel drive is essential to ensure superior performance compared to two-wheel-drive designs. In this article, as a comprehensive extension work to the article published in ASME Dynamic Systems and Control Conference [1] on all-wheel-drive (AWD) hybrid truck, we investigate the modeling, design, and control problem of AWD hybrid vehicles and develop a methodology to identify optimal designs. This methodology 1) formulates an automated modeling process, 2) searches exhaustively through all possible AWD designs, and 3) employs a near-optimal energy management strategy, to obtain a family of designs with superior performance and fuel economy. A design case study for a hybrid Ford F-150 is conducted, to showcase this design process
Pan, ZihengZhang, XiaowuPeng, HueiRavi, Nikhil
Velocity is one of the most important inputs of active safety systems such as ABS, TCS, ESC, ACC, AEB et al. In a distributed drive electric vehicle equipped with four in-wheel motors, velocity is hard to obtain due to all-wheel drive, especially in wheel slipping conditions. This paper focus on longitudinal velocity estimation of the distributed drive electric vehicle. Firstly, a basic longitudinal velocity estimation method is built based on a typical Kalman filter, where four wheel speeds obtained by wheel speed sensors constitute an observation variable and the longitudinal acceleration measured by an inertia moment unit is chosen as input variable. In simulations, the typical Kalman filter show good results when no wheel slips; when one or more wheels slip, the typical Kalman filter with constant covariance matrices does not work well. Therefore, a gain matrix adjusting Kalman filter which can detect the wheel slip and cope with that is proposed. Simulations are carried out in
Zhang, YamingLeng, BoXiong, LuYu, ZhuopingZeng, Dequan
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