Browse Topic: All wheel drive

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Definition and Measurement of Power Transfer Unit Speed-Dependent Parasitic LossJ3039_202012 (Current)12/30/2020
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
Heavy Dump TruckTBMG-3567512/1/2019
Mack Defense Allentown, PA 1 (800) 866-1177
WHAT WE'RE DRIVING19AUTP10_0710/1/2019
What first impresses about the GT is how easy it is to drive. Ingress is a little tricky over the wide sill, but once situated in the comfy driver's seat you use a strap to position the foot controls to your liking in a very cramped pedal box, and you have a few degrees of seatback angle to play with. The 3.5-L EcoBoost twin-turbo-charged V6 erupts to life from what feels like just behind your right earlobe, but settles quickly in a buzzing idle. Like many competition-focused machines, the V6 has a lightened-crank eagerness about it, but the “automatic” gearbox prevents any uneasiness about getting underway. Thanks to the rear-wheel-drive GT's low and centered mass, the engine can mutter away at low rpm while easily bringing the GT up to traffic speeds.
WHAT WE'RE DRIVING19AUTP09_089/1/2019
As the sporting player in Volvo's C-segment sedan lineup, this all-wheel drive, turbocharged-and-supercharged R-Design S60 faces benchmark competition in the BMW 3-Series, Audi A4 and Mercedes-Benz C-Class. In pure performance, the stylish Swede stacks up nicely against the Germans: Its 316 hp (236 kW) pushes the 3,900 lb (1769 kg) car plus my 200-lb (91 kg) of dead weight from a standstill to 60 mph (97 km/h) in 5.5 s, according to my stopwatch. Dynamically, the S60 T6 (not my choice of nomenclature, as it's a 4-cyl., not a six) feels solid and secure, if not exceptionally nimble, when pushed hard in the corners. But where the S60 R-Design clearly beats the others is inside, the area where Volvo shows its taillamps to the other premium brands. The S60's cabin is a beautifully integrated blend of rich materials and tasteful accents - brushed aluminum of the lower IP contrasting with deep ebony, offset by delightful-to-touch control knobs. The front seats are both handsome and comfortable. Rear-seat legroom is excellent, as my 37-in. (940-mm) inseam can attest.
Nissan concept sport sedan is all-electric, driver-optional19AUTP03_123/1/2019
Nissan looks to pump up the fun factor with the IMs, an all-electric sports sedan concept with autonomous driving capability. The car made its global debut at the 2019 North American International Auto Show. “While still being a driver's car, this concept lives within our very graspable future of creating/engineering a thrilling autonomous ride, bringing the car into the realm of ‘entertainment’, Giovanny Arroba, Nissan's program design director, told Automotive Engineering. IMs features dual electric motors in the front and the rear with an estimated 483 hp (360 kW) and 590 lb·ft (800 N·m) for all wheel drive capability. The 115 kWh battery pack, packaged under the floor, provides an estimated 380-mi (611.5-km) driving range. The sedan's dedicated EV platform essentially mirrors that of Nissan's IMx KURO electric crossover concept that debuted at the Tokyo Motor Show in 2017.
Buchholz, Kami
Cadillac pulls the wraps off two new V-Series sedans19AUTP08_191/1/2019
Cadillac has added two more sedans to its V-Series performance lineup, the 2020 CT4-V and CT5-V. The CT4-V will square off against established C-segment players such as the BMW 3-Series and Mercedes-Benz C-Class, along with Hyundai's new Genesis G70. The CT5-V will compete with the BMW 5-Series and Audi A6. The two new 4-door sedans join the larger 2019 CT6-V sedan in the V-Series stable, though the company noted that the series is evolving to be less focused on hard-core, track-worthy machines, and more about sporty and comfortable daily drivers. “We are inviting even more customers into the V-Series family,” said Brandon Vivian, Cadillac executive chief engineer, “by adding a new level of elevated performance between our Sport models and the ultimate, high-performance track capability that the V-Series has grown to represent.”
Seredynski, Paul
Porsche reveals eighth-generation of fabled 91119AUTP01_151/1/2019
Regularly updating and evolving the Porsche 911's aesthetic signature might seem an impossible task. But more than half a century after its birth, the unveiling of the eighth-generation at the 2018 L.A. Auto Show demonstrated that it is in fact still a totally possible art-with design boss Michael Mauer the chief artist. Designated in-house as the 992 series and slightly larger than the outgoing 991, it is launched in rear-wheel-drive and all-wheel-drive forms-Carrera S and Carrera 4S-and now only in the wide-body width previously used for the Carrera 4 GT3 and GTS, instead of two body widths. Across the nose, the new 911 is 45 mm (1.8 in) wider than the outgoing version, a figure some 911 purists may look at askance, as growth in recent years has already been considerable.
Birch, Stuart
VinFast: Vietnam's first car company has big ambitions18AUTP10_0610/1/2018
Vietnam's economy is expected to grow as much as 7% annually in the near-term, and with a population of around 90 million, its automotive market is expected to surge rapidly from the current 300,000 annual pace. And where sales are dominated by brands like Toyota and Hyundai, Pham Nhat Vuong is determined to grab a share for his new company, VinFast, which aims to become Vietnam's first major carmaker. Barely a year ago, 40% of the company's 827-acre manufacturing site was still underwater. There's still plenty of mud and debris, workers racing to pull things together. They don't have time to waste, considering the plan is to have the manufacturing complex up and running before mid-2019.
Eisenstein, Paul A.
Automotive Engineering: August 201818AUTP088/2/2018
LiDAR: new "eyes" for vehicle autonomy The steadily-evolving sensor tech offers big leaps forward in capability-once cost is reduced. e-Axles speed electrification Creating a practical 'bridge' between today's legacy ICE architectures and the electric future. McLaren earns its Ph.D in handling McLaren Automotive and the University of Cambridge collaborate on a no-compromise semi-active suspension for the 720S supercar. Jaguar's new EV pacesetter The 2019 I-Pace brings benchmark vehicle dynamics to the nascent battery-electric SUV segment. Editorial Connecting SAE with China's mobility future Supplier Eye Supplying the multi-energy platform The Navigator Traversing the autonomous trust gap What We're Driving 2018 Volvo XC40 T5 AWD; 2017 Toyota Land Cruiser; 2018 Toyota Corolla Eaton goes internal with its next-generation EGR solution Driver out, simulation in for AV transmission, driveline engineering Teaming carbon fiber-and embroidery? New Osram IREDs enhance vehicle vision without harming human eyes 2019 Acura RDX brings world's-first chassis tech All-new unibody 2019 Blazer goes stylish, not burly Nissan's entry-level Kicks makes its U.S. debut
Simulation Based Control Strategy Design of All Wheel Drive Electric Vehicle Regenerative Braking System2018-01-04114/3/2018
Maximising the recovered regenerative braking energy during the deceleration can significantly reduce the Electric Vehicle (EV) energy consumption and increase the range. Compared with the Front Wheel Drive (FWD) or Rear Wheel Drive (RWD) EV, an All Wheel Drive (AWD) EV with 2 electric machines (e-machines) has more control degree freedom when developing the regenerative braking control strategy. By implementing the regenerative braking at the front axle, rear axle, or at the front and rear axles simultaneously, the amount of recovered kinetic energy will be affected. Furthermore, the e-machines at the front and rear axle in the AWD EV can have different sizes or be the same. Therefore, the ratio between front and rear e-machine power rating should also be investigated to understand its effect on the amount of recovered energy during deceleration. This paper starts with the analysis of the vehicle braking behaviour compared over different driving cycles, and the comparison of two configurations of regenerative braking system, Category A and B. Then, the AWD EV is modelled, and its regenerative braking controller is developed using Ricardo in-house, proprietary simulation tools. The power rating of front and rear axle e-machines in this model is varied. The regenerative braking controller simulates Category A or B regenerative braking system with various control strategies (such as front axle or rear axle only regenerative braking, and all wheel regenerative braking). Simulation is done to investigate: 1) the difference in recovered energy by implementing the regenerative braking at different axles with Category A or B systems, and 2) how the ratio between the front and rear axle e-machine power rating affects the amount of recovered regenerative braking energy. This in turn affects the overall brake balance distribution and impacts upon vehicle stability. Finally, the simulation result is analysed and discussed.
Bao, Ran, Griggs, Philip, Baxter, James
Driving Force Coordinated Control of Separated Axle Hybrid Electric Dump Truck2017-01-246210/8/2017
Due to the increase of mining production and rising labor costs, manufacturers of construction and mining equipment are engaged in developing large tonnage mining truck with good dynamic performance and high transport efficiency. This paper focuses on the improvement of the dynamic performance of a 52t off-highway dump truck. According to the characteristics of its operating cycle, electric auxiliary drive system is installed in the front axle aiming at improving the utilization rate of ground adhesion. The new all-wheel drive hybrid electric system makes it possible for dump truck transports at a higher velocity. Both the conventional dump truck model and the new all-wheel drive hybrid truck model are built based on the AVL-Cruise platform. Meanwhile, under the premise of enough dynamic performance, fuel consumption can be minimized by collaborative optimization in Isight. Multi-island genetic algorithm is adopted to get proper powertrain parameters for its wide use in finding a global optimal solution. The collaborative optimization results show that the new hybrid dump truck obtains high dynamic performance without sacrificing the fuel economy. By comparing the simulation results we find that the maximum velocity of full load all-wheel drive hybrid electric dump truck increases by 19% at 8% slope, by 21.4% at 12% slope. All these improvements are of great significance to the transport efficiency and fuel economy of the dump truck.
Zhang, Ruipeng, Meng, Kaichuang
A Study on the NVH Problems Caused by the Additional Excitation Force of Propeller Shaft2017-01-17686/5/2017
The NVH performance is one of the most important concerns in vehicle development. For all-wheel drive (AWD) vehicles and rear-wheel (RWD) drive vehicles, prop shaft is a major transmission component which may cause various NVH problems. This paper focuses on the vehicle NVH problems caused by the second order excitation force of prop shaft. In order to control the NVH performance of the prop shaft efficiently and fundamentally, this work first studied the rotation kinematical characteristics of prop shaft. Then a rigid-elastic coupling model of vehicle driveline was built with the theory of multi-body dynamics. With this model, the sensitive factors that may affect the second order excitation force were investigated. This paper also describes a case study to verify the conclusions which are revealed from the theoretical calculation and the simulation. In this case, a vehicle vibration problem caused by the second order excitation force of prop shaft was successfully solved by following the indicative conclusions mentioned above. The main significance of this study is to establish an effective approach for analyzing and controlling the NVH issues related to vehicle driveline system. The indicative conclusions of this work could be referred by NVH engineers in the early phase of vehicle development.
Xu, Yong
New York auto show: Lincoln unveils all-new, aluminum-bodied 2018 Navigator17AUTP05_135/1/2017
Ford's Lincoln luxury-vehicle unit revealed the 2018 Navigator fullsize SUV at the 2017 New York auto show by touting its blend of smart basic engineering and smart features. Like the recently-revealed Ford Expedition, its Lincoln counterpart is fitted with weight-saving aluminum bodywork to cut roughly 200 lb (91 kg) from the curb weight and help offset the mass of the new Navigator's copious luxury and advanced driver-assist features.
Visnic, Bill
Evaluation of Stability and Control of Movement of 6x6 Truck for Different Operating Modes2017-01-15753/28/2017
Trucks are one of the most common modes of transport and they are operated in various road conditions. As a rule, all-wheel drive trucks are equipped with special systems and mechanisms to improve their off-road capability and overall efficiency. The usage of blocked mechanisms for power distribution is one of the most popular and effective ways to improve the off-road vehicle performance. However, the lock of differential may adversely affect the stability and control of vehicle because of the unobvious redistribution of reactions acting on wheels, which consequently leads to poor performance and safety properties. Problems of rational distribution of power in transmissions of all-wheel drive vehicles, as well as research in the field of improving directional stability and active safety systems are among the priorities in modern automotive industry. To study dynamics of a vehicle with wheel formula 6x6 a mathematical model of the vehicle was developed in an environment of LMS Amesim software package. The model includes the realization of the features of all major mechanical units of a vehicle: engine, transmission, suspension, drive wheels. Besides, the model takes into account the so called "external" dynamics of the vehicle and includes interaction of the wheels and pavement and implementation of possible changes in environmental conditions. With help of the mathematical model we have managed to estimate the trajectory and directional stability of all-wheel drive trucks with lockable differentials for different operating conditions. The results allowed us to develop the most effective, in terms of stability and control, algorithm for control of the power distribution system.
Keller, Andrei, Aliukov, Sergei, Anchukov, Vladislav
Statistical Characterization, Pattern Identification, and Analysis of Big Data2017-01-02363/28/2017
In the Big Data era, the capability in statistical and probabilistic data characterization, data pattern identification, data modeling and analysis is critical to understand the data, to find the trends in the data, and to make better use of the data. In this paper the fundamental probability concepts and several commonly used probabilistic distribution functions, such as the Weibull for spectrum events and the Pareto for extreme/rare events, are described first. An event quadrant is subsequently established based on the commonality/rarity and impact/effect of the probabilistic events. Level of measurement, which is the key for quantitative measurement of the data, is also discussed based on the framework of probability. The damage density function, which is a measure of the relative damage contribution of each constituent is proposed. The new measure demonstrates its capability in distinguishing between the extreme/rare events and the spectrum events. Several case studies including vehicle reliability, vehicle road test score, warranty, salary distribution of an institution, the city population distribution in 3 countries, and the earthquake distribution worldwide and in the USA, are provided to demonstrate the role of the statistical and probabilistic approaches in the characterization and analysis of the big data.
Wei, Zhigang, Nikbin, Kamran
Tailpipe Emissions and Fuel Economy for 2WD Vehicles and AWD Vehicles Tested on a Double-Axle Chassis Dynamometer: A Comparative Study2016-01-235410/17/2016
Tailpipe emissions, fuel consumption, and wheel torque data were measured for three pairs of vehicles tested over four drive cycles at the Emissions Research and Measurement Section of Environment and Climate Change Canada in Ottawa, Ontario. Each pair of vehicles included identical vehicle models; one vehicle was equipped with an AWD drivetrain and one vehicle was equipped with a FWD drivetrain. The AWD vehicle was tested on a double-axle chassis dynamometer. The amount of AWD activity was heavily dependent on driving behavior and AWD system design. During periods of torque delivery, the percentage of AWD activity ranged between 32% and 57% for the FTP-75 drive cycle, between 3% and 8% for the HWFCT drive cycle, and between 21% and 29% for the US06 drive cycle. The fourth drive cycle was the FTP-75 driven at -7°C. AWD distributions did not show sensitivity to temperature for the first and second vehicle models. The third vehicle model showed increases in AWD activity ranging from 27% to 33% at cold temperature. Vehicle fuel consumption increased with the amount of AWD activity, but was more sensitive to the additional weight of AWD components. Fuel consumption increases ranged between 2.2% and 13.9% for the FTP-75 drive cycle, between 1.6% and 7.8% for the HWFCT drive cycle, between 0.4% and 7.7% for the US06 drive cycle, and between 9.0% and 15.7% for the cold temperature FTP-75 drive cycle. There were no statistically significant differences in emissions of CO, NOx, and THC between the FWD and AWD vehicles.
Conde, Aaron J., Christenson, Martha, Richard, Brad
Development of Advanced Braking System for Hybrid Sports Cars2016-01-19239/18/2016
An advanced braking system had to be developed for a next-generation hybrid sports car with Sport Hybrid Super Handling All-Wheel Drive to achieve an intuitive brake feeling in a variety of driving conditions, ultimate track performance and reduction of CO2 emissions per vehicle. This paper outlines the integration of brake-by-wire with traditional high-performance braking hardware and describes the technology needed to achieve these goals. Key focus areas to generate these results were: brake feeling control, corner hardware specification considerations and brake cooling.
Dyar, Lorne R., Akita, Yuichiro, Paul, Scott, Lepito, Joseph, Ishikawa, Yoshio, Watanabe, Tomohiro
Automotive Engineering: March 3, 201616AUTP033/3/2016
Multi-material structures move mpg upward The quest to improve fuel economy is not waning, nor is the desire to achieve higher mpg through the use of just the right lightweight material for the right vehicle application. Cars poised to become 'a thing' Making automobiles part of the Internet of Things brings both risks and rewards. Agility training for cars Chassis component suppliers refine vehicle dynamics at the high end and entry level with four-wheel steering and adaptive damping. SAE 2016 World Congress Preview Technology trends and exhibitor products are highlighted in this special section, which features Toyota's plans for the show floor, tech sessions, and more. Rethinking the route to lower-cost fuel cells Secondary loop and heat pump climate control under evaluation once more OTA reflashing: the challenges and solutions 3D-printed high-temperature ceramics 2017 Pacifica is first hybrid minivan, rides on all-new FCA platform Prius is re-engineered on Toyota New Global Architecture 2017 Porsche Boxster loses cylinders, gains power, adds frugality 2016 Mini Clubman's torque-vectoring AWD system designed to give 2wd efficiency
Dynamic Stiffness Estimation of Elastomeric Mounts Using OPAX in an AWD Monocoque SUV2015-01-21906/15/2015
Mount development and optimization plays an important role in the NVH refinement of vehicle as they significantly influence overall driving experience. Dynamic stiffness is a key parameter that directly affects the mount performance. Conventional dynamic stiffness evaluation techniques are cumbersome and time consuming. The dynamic stiffness of mount depends on the magnitude of load, frequency of application and the working displacement. The above parameters would be far different in the test conditions under which the mounts are normally tested when compared to operating conditions. Hence there is need to find the dynamic stiffness of mounts in actual vehicle operating conditions. In this paper, the dynamic stiffness of elastomeric mounts is estimated by using a modified matrix inversion technique popularly termed as operational path analysis with exogenous inputs (OPAX). The test vehicle is an all-wheel drive (AWD) monocoque vehicle which has power train in east-west configuration and a rear drive module (RDM) used to transfer the drive to rear wheels. The dynamic stiffness values of power train mounts, front sub frame and rear sub frame mounts and RDM mounts are determined by OPAX method. The result is used in building a simulation model to analyze vehicle driveline NVH. The new method has increased the efficiency of computation by reducing the number of FRF measurements. OPAX method takes into account the multiple order based data unlike matrix inversion method. Guidelines for the selection of operating conditions and selection of orders are discussed to improve the quality of simultaneous equations and to reduce the ill-conditioning of matrix. The influence of assumption of constant stiffness over certain band width on the stiffness pattern is analyzed. Drawbacks of the method in estimating the stiffness in some of the paths where force level and attenuation level are negligible are discussed. The predicted dynamic stiffness data is also used in finding the dynamic forces in other operating conditions of the vehicle.
Rao, Manchi Venkateswara, Moorthy, S Nataraja, Raghavendran, Prasath
Experimental Investigation of Effect of Driveline Torsional Fluctuations on Overall NVH Performance of the Vehicle2015-01-21926/15/2015
Meeting various customer(s) requirements with the given automotive product portfolio within the stipulated time period is a challenge. Design of product configuration matrix is an intelligent task and it requires information about vehicle performance for different configurations which helps in deciding the level of new development. Most often the situation arises, particularly in the field of NVH, to strike the right balance between engine power and structural parameters of the body. The sensitivity of engine power on the overall NVH behavior is the key information necessary to take major business decisions. In this paper, the effect of change in torsional fluctuation of the engine on the NVH behavior of the rear wheel drive vehicle is experimentally studied. The torsional fluctuation of the driveline is given as an input with the help of an electric motor to the existing test vehicle at its differential end and the current NVH levels are measured. A test rig is built to change the levels of torsional vibration input to the vehicle. The threshold level of torsional fluctuation for the given vehicle structure is obtained by taking into account the target values of tactile vibration and subjective perception. The results are very useful in deciding the acceptable level of change in engine power without carrying any structural change. Also, for a given power, the set of structural changes necessary in the body and suspension linkages to meet the NVH criteria can be studied. The procedure is also extended to an all-wheel drive vehicle with the help of a two wheel drive chassis dynamometer. Obtaining subjective perception of the vehicle NVH even before making the vehicle of target configuration is an inherent advantage of the proposed technique. A good correlation is achieved with the objective results and subjective perception.
Rao, Manchi Venkateswara, Frank, Jos, Raghavendran, Prasath
Development of Handling Performance Control for SPORT HYBRID SH-AWD2015-01-15754/14/2015
We have developed control logic for the Sport Hybrid system with Super Handling All-Wheel Drive (SPORT HYBRID SH-AWD), which can achieves a balance between high maneuverability and heightened fuel economy. The former is realized by effective torque vectoring using two motors capable of independent regeneration and driving the left and right rear wheels, and the latter is realized by the hybrid system. Taking advantage of the benefits of using motors enables effective torque vectoring that is highly responsive from low vehicle speeds regardless of the engine driving force. By means of a control technology that makes advantageous use of this system's characteristics, this approach did not just achieve a limitation of increased turning radius when accelerating in a turn, which has been the main torque vectoring effect realized to date. Rather, it was further able to achieve an “on-the-rail” feeling that is quick, linear, and highly stable to an extent that anyone could perceive in a variety of situations that are closer to what customers ordinarily encounter.
Honda, Tomokazu
General Motors Front Wheel Drive Seven Speed Dry Dual Clutch Automatic Transmission2015-01-10934/14/2015
General Motors has introduced a new front wheel drive seven speed dry dual clutch automatic transmission in 2014. The 250 Nm input torque rated gear box was designed and engineered for a global market in both front wheel drive and all-wheel drive configurations. The transmission has integrated start/stop capability enabled by the use of an electric motor driven pump and a pressurized accumulator. The architecture selected was chosen for optimization of packaging, fuel economy, mass, shift pleasability, and NVH. High mileage durability and world class drivability were the cornerstone deliverables during the engineering and design process Fuel efficiency is estimated to be 3% - 10% improvement over a conventional six speed automatic transmission. FWD variant wet mass of 78.1 kg was achieved through the rigorous engineering processes used to optimize the transmission system.
Clark, Kirby S., Singh, Tejinder, Buffa, Ronald P., Gayney, Jack M., Cousins, William L., Xie, Zhe, Moorman, Steven P., Wilson, Alexandria, Fannin, Michael P., Graham, Mark L., Preston, Christopher B., Solt, Michael B., Varda, David J., Gilmore, Mark R., Foulkes, Martin G., Risko, Rebecca K.
Automotive Engineering: April 7, 201515AUTP044/7/2015
GM's CTO driving new paths to technology leadership 'We're making actual production commitments regarding our advanced-technology strategy, rather than just talking about it,' says GM's CTO Jon Lauckner. 'We're absolutely going to be among the leaders, if not the leader, in these areas.' Aluminum prepares for its next big leap Ford's F-Series blockbuster was just the beginning. New micromills now in pilot phase aim to bring vastly stronger and more formable light-alloy materials at higher capacity, says Alcoa's Mike Murphy. Slick solutions for friction reduction From new lubricants to 'smart' oil pumps and clever bearing technologies, engine designers are attacking every potential source of spin losses and internal friction in the quest for more mechanical work out of less fuel. Next-gen NSX: a twin-turbo, multi-material Ferrari-fighter The production NSX made its much-awaited global debut at NAIAS in January. More technical details of Acura's mid-engine AWD hybrid supercar will be shared by Honda R&D experts at the SAE 2015 World Congress.
Automotive Engineering: February 3, 201515AUTP022/3/2015
Getting a grip on AWD efficiency The safety and performance benefits of all-wheel drive are undeniable, but so are the penalties of added weight, friction losses, and complexity. Clever axle disconnects and E-axles are driving future AWD developments. E pluribus unum Inputs from many sensors are being combined to give safety systems a true vision of vehicle surroundings, with the resulting sensor fusion becoming a mainstay of autonomous vehicle electronics. Lightweighting poses repair challenges Mass-produced aluminum bodies and mixed-material structures present challenges for assembly and repair, as automakers increasingly pursue these lightweight strategies. Setting the standard Meggitt CTO Emeritus begins term at helm of SAE International, seeks to encourage cross-sector relations, elevate image of SAE as aerospace industry leader.
Safe and Eco Friendly Train Traction System with No Rails2014-01-22899/30/2014
In this research paper, a novel train traction system is described. In this system, the vehicle is lifted like a hovercraft by air cushion and the traction is achieved by using horizontally mounted all-wheel drive. Chance of derailment is completely eliminated and wherein even in the event of failure of few traction wheel stations during run, the train remains mobile with absolute safety even at high speeds. All-wheel drive traction is powered by overhead electrification to maintain high power to weight ratio and faster acceleration. In the present invention, no rail is used. This eliminates the enormous cost of laying the complex and expensive railway tracks. Other advantages include the lack of exhaust fumes and carbon emissions at point of use especially in countries where electricity comes primarily from non-fossil sources, less noise, lower maintenance requirements of the traction units. In case, where the availability or laying the overhead electrification is an issue, the present invention has the potential to adopt alternate power sources such as petrol or diesel or gas turbine or jet engines or hybrid power sources for traction. But ecological issues may have to be compromised in such cases. The present invention has a potentially wide scope to revolutionize urban and suburban railway traction (both passengers and goods) and long distance traction. For proving the technical feasibility, a working model was developed. In this paper, the results from the working model are discussed in detail. (Indian patent and PCT application are pending).
Giridharan, K
Electric Drive System for SPORT HYBRID SH-AWD2014-01-18214/1/2014
We have developed the new SPORT HYBRID SH-AWD system, a hybrid system that provides best in class fuel economy and drivability to exceed customer expectations. The powertrain has a V6 engine and comes with three drive types modes: front wheel drive powered by a 7-speed dual clutch transmission with one built-in motor, rear wheel drive powered by a twin motor unit with two built-in motors, and all-wheel drive powered by a combination of the two. The system can automatically select the most efficient drive method for the driver's needs and the road conditions. The two motors built into the twin motor unit are individually controlled and torque vectoring is used to create a torque difference between the left and right tires, improving the turning performance. The electric drive system was developed with consideration for layout feasibility and quietness. The two motors built into the twin motor unit and the inverter that drives the motors have been newly developed. By installing this system in the 2015 model year RLX, we achieved engine performance equivalent to a car with a V8 engine at 0-60 mph in 5.4sec and fuel economy equivalent to a car with an L4 engine at 30 mpg.
Ono, Koichi
Analysis of Drive Line Vibration and Boom Noise in an All Wheel Drive Utility Vehicle2014-01-19754/1/2014
The customer demand for all wheel drive (AWD) vehicles is increasing over the period of time which also requires NVH performance on par with front wheel drive vehicles. AWD vehicles are equipped with power transfer unit, propeller shaft and independent rear differential assembly to achieve their functional requirement. The additional drive train components in AWD vehicles may amplify torsional fluctuations in the drive line. Hence achieving the NVH performance of AWD vehicles on par with FWD vehicles without any major change in the existing design is a major challenge. In this work, an AWD vehicle with severe body vibration and booming noise is studied. The operational measurements are taken throughout the drive train on all sub-systems from engine to the rear part of the body in the problematic operating condition. An operational deflection shape analysis is conducted to visualize the vibration behavior of the drive train. The result of analysis shows that the dynamic torsional fluctuations of the drive shaft and rear drive module (RDM) vibration are the major contributors for the high levels of vibration and noise. Powertrain torsional vibration measurements are also carried out with and without the part of the drive train that belongs to AWD. The reduction in vibration to certain extent is achieved by optimizing the stiffness of RDM mounts. The complete vibration and boom is eliminated by installing a tuned mass damper on RDM. The reduction of 4 dB (A) in interior noise and 5 dB in seat vibration are achieved with the effect of modifications.
Rao, Manchi Venkateswara, Frank, Jos, Raghavendran, Prasath
Advanced Vehicle Powertrain Design, Validation, and Integration for the EcoCAR 2 Advanced Vehicle Technology Competition2014-01-19264/1/2014
For the EcoCAR 2 collegiate engineering competition, The University of Tennessee is modifying a 2013 Chevrolet Malibu Eco from a mild hybrid into a series-parallel plug-in hybrid electric vehicle. For this design, the team is exchanging the engine for one that is E85 compatible, slightly separating the engine and transmission, and coupling an electric generator to the engine. In the rear of the vehicle, a modified all-wheel drive subframe will be implemented. This subframe will house a traction motor and a single gear electric drive transmission. A custom fuel tank and fuel system will be constructed for the vehicle, in order to use E85 fuel. Furthermore, an energy storage system will be placed in the rear of the vehicle, in the trunk and spare tire space. Modifications for the packaging must be made and analysis must be performed to validate the structural integrity of all modifications. Tennessee's engineering team is made up of five specific groups: mechanical, thermal, electrical, controls, and center stack teams. This report details the work that was done strictly by the mechanical team in Year Two. This paper outlines the general design of the powertrain, the changes made to the architecture and vehicle components during Year Two of the competition, the analysis performed on modified and replacement components, and the actual implementation of the components into the Malibu.
Utley, John P., Irick, David K.
Simulation and Analysis Drive Transmission DevelopmentTBMG-172079/1/2013
Vicura is a developer of manual transmissions and dry dual clutch transmissions, as well as powertrain integration in a large number of front wheel drive and all wheel drive applications. The company’s engineers are responsible for a broad range of complex simulation and analysis testing including system, structure, and fluid mechanics. The team performs critical simulation and analysis to ascertain the strength, stiffness, thermal, and dynamic behaviors of all possible transmission assemblies and components (housings, shafts, gears, synchronizers, clutches, etc.).
Conceptualization and Implementation of an AWD Parallel Hybrid Powertrain Concept2013-01-14484/8/2013
The Deep Orange [1] initiative is an integral part of the automotive graduate program at Clemson University International Center for Automotive Research. The initiative was developed to provide the graduate students with hands-on experience of the knowledge attained in the various engineering disciplines and related disciplines (such as marketing and human factors psychology). For the 3rd edition of Deep Orange, the goal was to develop a blank sheet hybrid mainstream sports car concept targeted towards the Generation Y (Gen Y) market segment. The objective of this paper is to elaborate on the overall development process and the technology that was created and integrated. A unique all-wheel-drive (AWD) parallel hybrid concept was derived based on extensive analyses of the Gen Y market. The data revealed that Gen Y, as an environmentally conscious generation, is willing to invest in sustainable powertrain technologies and also has a significant interest in all-wheel-drive. Based on these findings, a through-the-road parallel hybrid powertrain concept with a manual transmission was conceptualized. The powertrain architecture comprises of a Front-Wheel-Drive (FWD) concept using a downsized turbocharged 4-cylinder Internal Combustion Engine (ICE) and a Rear-Wheel-Drive (RWD) concept using an electric machine. This configuration allows for regenerative braking, all-wheel-drive and power boost functionality. In the early development phase of the project, simulation models were developed for sizing the powertrain components using model-based design tools in order to achieve functional targets while carefully balancing cost, weight and design-space. This paper will elaborate on how the unique hybrid powertrain setup was developed based on a holistic systems engineering approach incorporating competing aspects such as performance, fuel economy, exterior/interior design and powertrain component packaging.
Venhovens, Paul, Pisu, Pierluigi, Prucka, Robert, Makkar, Bhavuk, Frommann, Patrik, Sonavane, Tejas, D'Amico, Chris
The Design, Development and Industrialization of an New 8 Speed Automatic Transmission in China2013-01-12774/8/2013
Shengrui Transmission Limited Corporate (Shengrui) has developed a new 8 speed automatic transmission (SR 8AT) for front wheel drive (FWD) vehicle. The concept of SR 8AT is unique and different from the conventional automatic transmission. The design of the SR 8AT system and components are new and compact. By combining an innovative gear train which is similar with the conventional manual transmission and the simple planetary gear structure, SR 8AT achieved 8 speed with the shortest length of the FWD transmission, the competitive fuel economy and the smooth shift performance among comparable automatic transmissions.
Lu, Jan Gang
Application of a Novel Metal Folding Technology for Automotive BiW Design2013-01-03734/8/2013
The Deep Orange [1] initiative is an integral part of the automotive graduate program at Clemson University International Center for Automotive Research. The initiative was developed to provide the graduate students with hands-on experience of the knowledge attained in the various engineering disciplines and related disciplines (such as marketing and human factors psychology). For the 3rd edition of Deep Orange, the goal was to develop a blank sheet hybrid mainstream sports car concept targeted towards the Generation Y (Gen Y) market segment. The objective of this paper is to explain the unique body-in-white (BiW) concept that offers space for 6-passengers and includes a dual-mode hybrid all-wheel drive powertrain. An additional objective of the project was to develop and showcase a body-in-white concept that will eliminate metal stamping and high capital investments associated with this technology (such as dies and stamping tools). It was chosen to explore Industrial Origami's patented technology that uses lighter gauge material folded into complex, innovative, high load-bearing structures, formed with simple, low cost fixtures, at the point of assembly. Developing the topology, geometry and functionality of the BiW required an intensive collaboration between design students and chassis, powertrain, NVH and occupant packaging engineering students while carefully balancing functional properties, design space, cost and weight. Once the properties and design targets were met, the complete sheet Folded Metal Technology (FMT) design was realized using aluminum and structural adhesives. In addition to describing the conceptual analyses, the paper will also elaborate on the final realization of the BiW concept.
Venhovens, Paul, Bell, Keith, Marathe, Prathamesh, Patkar, Aniket, LaMance, Frederick, Lind, Daniel, D'Amico, Chris
The ZF Automatic Transmission 9HP48 Transmission System, Design and Mechanical Parts2013-01-12764/8/2013
With the 8HP transmission generation, ZF established a model range on the market offering considerable progress in terms of fuel savings, power-to-weight ratio, and functionality. A front-transverse transmission derived from the 8HP transmission generation gear set concept leads to higher design costs and to an unfavorable design, contradicting the very restricted installation spaces for front-transverse transmissions. With the transmission concept of the 9HP48 transmission, the advantages of the 8HP transmission generation were successfully transferred to a front-transverse transmission design and, at the same time, all restrictions regarding the installation space were solved. Thanks to its number of gears the high efficiency and the reduced drag torque, the 9HP48 transmission delivers fuel savings of up to 16 percent compared with today's standard 6-speed automatic transmissions with front-transverse installation. The publication gives a detailed description of the mechanical design of the 9HP48 transmission. By means of a new gear set concept with 4 planetary gear sets and 6 shift elements, the requirements regarding high efficiency and a large total spread that are important for achieving fuel savings and comfort can be realized at low gear steps. For the first time, two positive locking dog clutch shift elements are applied alongside an axially parallel vane cell pump to reduce the drag torques. In order to achieve compatibility between the transmission's design and the installation spaces of typical front-transverse vehicles, a completely new transmission architecture is used. In addition to the new architecture, the achievement of installation targets is facilitated by two dog clutches, two planetary gear sets nested on top of each other, and multi-disk clutches, as well as a new torque converter design. In addition, the 9HP48 transmission is designed according to a modular principle. As a result, the basic transmission can be supplemented depending on the requirements and customer wishes. Thus, different starting elements and all-wheel drive applications can also be implemented at optimal cost in the restricted installation space conditions of front-transverse passenger cars.
Gaertner, Lutz, Ebenhoch, Michael
Development of a Standard Spin Loss Test Procedure for FWD-Based Power Transfer Units2013-01-03614/8/2013
As vehicle fuel economy continues to grow in importance, the ability to accurately measure the level of efficiency on all driveline components is required. A standardized test procedure enables manufacturers and suppliers to measure component losses consistently and provides data to make comparisons. In addition, the procedure offers a reliable process to assess enablers for efficiency improvements. Previous published studies have outlined the development of a comprehensive test procedure to measure transfer case speed-dependent parasitic losses at key speed, load, and environmental conditions. This paper will take the same basic approach for the Power Transfer Units (PTUs) used on Front Wheel Drive (FWD) based All Wheel Drive (AWD) vehicles. Factors included in the assessment include single and multi-stage PTUs, fluid levels, break-in process, and temperature effects. The resultant procedure is proposed as a new SAE J-standard (Surface Vehicle Recommended Practice) for release by the AWD Standards Committee. The overview presented in this paper includes definitions for the PTUs used in the study along with an overview of the test setup and instrumentation. This paper will outline some of the key investigations undertaken including the step size and duration, assessment of repeatability, as well as the influences of break-in and oil level. This project was undertaken and financially supported by the Transmission Working Group of the United States Council of Automotive Research (USCAR) for the SAE AWD Standards Committee.
Kirk, Michael P., D'Anna, Thomas, Seldon, William, Perakes, Andreas, Ross, Craig
AWD Disconnect Solutions “ZF ECOnnect”2013-01-03624/8/2013
Under the name “ZF ECOnnect”, ZF has recently developed a variety of AWD driveline solutions with an available AWD disconnect function. The ZF AWD disconnect systems are mainly designed for FWD-based AWD architectures and greatly help to solve the conflict between AWD performance the additional fuel consumption caused by AWD in comparison to FWD. AWD disconnect means that when no AWD function is required, there will be no torque transfer to the secondary axle. Therefore, the speed-dependent losses due to friction and oil churning are avoided by bringing the normally rotating elements to a standstill, while the vehicle is still driving. Compared to a conventional hang-on AWD system, the disconnect system therefore reduces the friction losses in the AWD driveline by up to 90% in the disconnected mode. This is achieved by the overall design of the units including special features and optimized coupling elements resulting in very low drag torque. The mode change between 2WD and AWD is performed according to an operation strategy and takes place on the move - fast and seamless for the driver, while still providing full AWD-performance when needed. The ZF developed products include PTUs with different type and style of disconnect features, Single- and Twin-Clutch RDUs as well as the control strategies and software required to ensure the disconnect- and AWD function. The coupling and decoupling processes are realized with the help of precisely controlled electro-mechanical or electro-magnetic actuators which are tuned for the right balance between rapid shifting action and good comfort during the shifting process. In addition to the fuel economy improvement, the Twin-Clutch RDU also provides enhanced traction and driving dynamics as the drive torque can be distributed between the rear wheels as appropriate for specific conditions. With the ZF ECOnnect solutions, different customer requirements in terms of costs, utility, and function are covered. Based on initial bench testing, demonstrator vehicles have been established to validate and tune the function and performance of the developed solutions. This paper describes the different solutions including their specific design elements, performance and control as well as specific information regarding actual test results.
Peter, Robert, Granzow, Claus, Arzner, Matthias, Vogel, Volker
The University of Waterloo Alternative Fuels Team's Approach to EcoCAR 22012-01-17619/10/2012
A series plug-in hybrid electric powertrain with all-wheel drive is designed using real-world drive cycles as part of the EcoCAR 2 competition. A stock 2013 Chevrolet Malibu Eco is being re-engineered to reduce fuel consumption and emissions while improving consumer acceptability. Waterloo utilizes a 18.9 kWh A123 energy storage system (ESS), which powers two 105 kW TM4 traction motors. A 2.4 L LE9 General Motors coupled to a 105 kW TM4 motor provides range extending performance. Each step of the design process is discussed, including a novel approach to powertrain selection and controls requirement selection that uses real-world drive cycles. The mechanical integration and unique ESS design is also discussed.
Singh, Gurhari Preet, Cremasco, Mark, Evenchick, Eric, Lo, Josh, Karpinski-Leydier, Michael, Sabiston, Trevor, Walton, Brandon, Fraser, Roydon A., Fowler, Michael
Development of a Fuzzy Slip Control System for Electric Vehicles with In-wheel Motors2012-01-02484/16/2012
A two-passenger all-wheel drive urban electric vehicle (AUTO21EV) with four direct-drive in-wheel motors and an active steering system has been designed and developed at the University of Waterloo. A novel fuzzy slip control system is developed for this vehicle using the advantage of four in-wheel motors. A conventional slip control system uses the hydraulic brake system in order to control the tire slip ratio, which is the difference between the wheel center velocity and the velocity of the tire contact patch along the wheel plane, thereby influencing the longitudinal dynamics of a vehicle. The advantage of the proposed fuzzy slip controller is that it acts as an ABS system by preventing the tires from locking up when braking, as a TCS by preventing the tires from spinning out when accelerating. More importantly, the proposed slip controller is also capable of replacing the entire hydraulic brake system of the vehicle by automatically distributing the braking force between the wheels using the available braking torque of the in-wheel motors. In this regard, the proposed fuzzy slip controller guarantees the highest traction or braking force on each wheel on every road condition by individually controlling the slip ratio of each tire with a much faster response time. The performance of the proposed fuzzy slip controller is confirmed by driving the AUTO21EV through several test maneuvers using a driver model in the simulation environment. As the final step, the fuzzy slip controller is implemented in a hardware- and operator-in-the-loop driving simulator and its performance and effectiveness is confirmed.
Jalali, Kiumars, Uchida, Thomas, McPhee, John, Lambert, Steve
A Novel Method of Axle Torque Measurement for Off-Road Vehicles2012-01-03104/16/2012
Most vehicles designed primarily for off-road use - whether for the SUV, military, agricultural or earthmoving industries - employ all wheel drive systems. For off-road conditions where the traction is limited by the deformable nature of the ground, for example, loose track, soil or sand, providing a drive torque to all the wheels is the obvious design solution for maximising the total tractive effort. For military or commercial vehicles, this results in optimum mobility in difficult terrain, whereas for agricultural or earthmoving vehicles it often results in optimum work rates. In order to analyse the performance of off-road vehicles, it is necessary to understand the torque and power flows through the driveline system to each axle or wheel. The research presented in this paper focuses on the use of novel, non-contact torque sensors to measure the driveline torque distribution. The example vehicle is a four wheel drive (4WD) agricultural tractor - but it is proposed that the same measurement techniques could be applied to any off-road vehicle. The torque sensor is a non-contact, bi-directional transducer based on the magnetostrictive principle. The shaft to be measured has a chevron pattern plated on to its surface in copper - and then around this is placed a sensor housing with sets of primary and secondary windings. When a torque is applied to the shaft, the change in magnetic flux of the copper chevrons is sensed in the windings. The benefits of this system include simplicity, reliability, linearity compactness and ease of fitting. These features enabled torque measurements to be made at the input to the main gearbox (engine output torque) and the front and rear driveshafts of the tractor. The driveline measurement system in practice demonstrated substantial improvements over previous systems described in the literature, all of which appear to have been based on strain-gauge type devices. The paper describes the experiences of using this system in field measurements with the tractor operating in high draught force conditions - as is normal for many agricultural tasks. Example results are used to show that the torque and power flows through the driveline are not as straightforward as previous research has suggested - the tractive force vs wheelslip characteristics at the front and rear tyres can cause interactions which result in unanticipated front and rear axle torque distributions.
Guy, Ianto
Development of a Standard Spin Loss Test Procedure for 4WD Transfer Cases2012-01-03064/16/2012
As vehicle fuel economy continues to grow in importance, the ability to accurately measure the level of parasitic losses on all driveline components is required. A standardized comparison procedure enables manufacturers and suppliers to measure component losses consistently, in addition to offering a reliable process to assess enablers for efficiency improvements. This paper reviews the development of a comprehensive test procedure to measure transfer case speed-dependent parasitic losses at key speed, load, and environmental conditions. This procedure was validated for repeatability considering variations in soak time, temperature measurement positions on the transfer case, and test operating conditions. Additional assessments of spin loss at low ambient temperatures, and the effect of component break-in on spin loss were also conducted. The resultant procedure is proposed as a new SAE J-standard (Surface Vehicle Recommended Practice J2985) for release by the All Wheel Drive (AWD) Standards Committee. This project was undertaken and financially supported by the Transmission Working Group of the United States Council of Automotive Research (USCAR) for the SAE AWD Standards Committee.
Kirk, Michael, Ilyas, Syed M., D'Anna, Thomas, Perakes, Andreas E., Ross, Craig S.
Axle Drive and Brake-Based Traction Control Interaction2011-01-21609/13/2011
Brake-based traction control systems (TC), which utilize the brake of a spinning wheel of the drive axle, are widely used in passenger cars and light trucks, and recently were applied to all-wheel drive construction equipment. Such machines employ various types of interwheel drive systems (i.e., axle drives such as open differentials, limited slip differentials, etc.) to control torque split between the drive wheels and, thus, improve vehicle traction performance. As experimental research showed, the interaction between the traction control system and the axle drive can lead to unpredictable changes in vehicle performance. Lack of analytical work in this area motivated this study of the interaction and impact of the two systems on each other and the dynamics and performance of a drive axle. The paper presents an analysis of the torque/force distribution between the driving wheels of an axle with open differential and limited slip differential with different torque bias characteristics when the traction control system is on and the driving wheels have the same/different gripping conditions. Also, the normal tire loads vary due to lateral inclination of the axle. Results of analytical research explain the nature of extra torque loads of the wheels, determine the yaw moment, and show energy losses in tires and the axle brake mechanisms. These results layout the requirements needed for the braking torque and control algorithm development of the traction control system to work “cooperatively” with limited slip differentials.
Vantsevich, Vladimir V., Bortolin, Gianantonio
Estimation of Sideslip Angles of a Volvo A25E Articulated All-Wheel Drive Hauler Based on GPS/INS Measurements2011-01-21569/13/2011
We describe an off-line estimator for the sideslip angles of an articulated off-road vehicle based on measurements from Global Positioning System (GPS) and Inertial Navigation System (INS). The current implementation is a proof of concept and the intention is to develop a system that can be used as a reference for on-line estimators. By comparing measurements from two GPS/INS units, mounted on the front and rear part of the vehicle, it is possible to estimate the sideslip angles of both the front and rear part. The method has been tested on a Volvo A25E articulated all-wheel drive hauler equipped with two high precision GPS/INS units (NovAtel's SPAN-CPT). Tests have been performed when driving on asphalt, gravel and snow. The results from the tests are discussed.
Andersson, Ulf, Bortolin, Gianantonio, Backén, Staffan, Gustafsson, Thomas
All-Wheel Drive Systems ClassificationJ1952_201010 (Historical)10/14/2010
In this SAE Recommended Practice, attention will be given to passenger cars and light trucks (through Class III).
Drivetrain Standards Committee
Approaches to Achieving AWD Torque Accuracy2008-01-03034/14/2008
In an actively managed AWD driveline system, a vehicle-level controller communicates a torque request to a torque-transfer device which couples the front and rear drive axles, in order to achieve a desired vehicle behavior. The accuracy with which the coupling device responds to the torque request has a significant impact on both the vehicle performance and the durability of the driveline. Inaccurate torque response may affect vehicle performance by degrading vehicle traction, handling, and stability, or by producing undesirable NVH behavior. Driveline durability may be at risk in modern vehicles where lighter, lower-cost driveline components require that driveline torque be limited, in order to prevent mechanical failure. The degree to which the AWD system is successful in accurately transferring torque is dependant upon several factors, including unit-to-unit production variation inherent in the manufacturing process, mechanical and electrical component variation over the range of operating conditions, and changes in the characteristics of the coupling over the expected life of the system. This paper discusses several methods which may be employed to reduce or compensate for these sources of inaccuracy, including factory break-in, controls calibration, and controls compensation for thermal operating conditions. Data is presented which indicates that these methods complement each other in producing a more accurate torque response.
West, Russell S., Haselton, David
Development of NexTrac™ Electronic Driveline Coupling for Front-Wheel Drive Based All-Wheel Drive Applications2007-01-06604/16/2007
There is a significant market shift taking place between RWD and FWD based AWD segments. The industry is experiencing a tremendous growth of FWD based AWD with the majority of new FWD platforms offering an AWD derivative. This has created demand for higher performing, cost effective, electronically controlled on-demand AWD couplings. To meet this demand BorgWarner, has developed a new electronically controlled driveline coupling called NexTrac™. NexTrac™ is a significant departure from conventional electro-magnetically actuated FWD/AWD couplings prevalent in the market today. The most distinct new feature is the direct actuation of the primary clutch by an electro-mechanical system using organic friction material for the primary clutch plates instead of steel. This, and other features give NexTrac superior lifetime NVH performance and cost effective driveline integration.
Barlage, John, Mastie, Joseph, Niffenegger, Donn
Automotive Engineering International 2006-10-01AUTOOCT0610/1/2006
Like a rolling home Suppliers are helping automakers engineer vehicles that allow passengers to bring along the comforts of home. Focusing on distraction An explosion of new features, functions poses challenges for safety. Performance goes green With record-high fuel prices and CO2 concerns providing the impetus, automakers are developing more fun-to-drive cars with an eye towards efficiency. GM re-engineers pickips More refined ride, higher-quality interiors, and greater efficiency are some of the highlights of the 2007 models. Jeep takes on tough terrain For 2007, the brand's iconic Wrangler is engineered to be more rugged off-road and more refined on it. Audi updates TT theme The second-generation rendition is bigger, more powerful, and uses a subtle metals mix and match. Vantage: as Aston to the core A common platform strategy is a vital element of the company's design and manufacturing flexibility. Lexus hybridizes sports sedan The GS450h is the world's first series production ICE-electric hybrid in a front-engine, rear-wheel-drive configuration, according to Toyota. Turbocharging the 911 The high-performance Porsche model is packed with technology including variable turbine geometry turbocharging, advanced all-wheel drive, and advanced air management to help it reach 309 km/h (192 mph). Larger, more agile Santa Fe asserts itself The "urban crossover" is Hyundai's first production vehicle designed at its styling studios in California.
General Motors New Hydra-Matic RWD Six-Speed Automatic Transmission Family2006-01-08464/3/2006
The Hydra-Matic 6L80 is General Motors first model of a new, four-variant, rear wheel drive (RWD) six speed automatic transmission family. The four variants are the 6L45, 6L50, 6L80 and 6L90. The new, high performance 6L80 will debut in 2006 model year performance vehicles, including the Chevrolet Corvette C6 and new Cadillac STS-V and XLR-V. By 2007, GM expects to use the RWD six speed family in as many as 25 different car, truck and SUV models in RWD, 4WD and all-wheel drive configurations. While the Hydra-Matic RWD six-speed family was designed with four variants, the built in modularity requires only two different basic diameters of parts and “flexing” on part width (length) depending on specific torque requirements. This built in modular design enables a tremendous amount of part sharing and part scaling. Modularity minimizes engineering resources, improves investment and piece cost, speed to market and allows for a wide bandwidth of vehicle and engine applications. The current bandwidth of applications ranges from 2.5 L to 6.6 L engines. The planned engine torque capacity for the family ranges from 258 lb.-ft. to 520 lb.-ft. (350 Nm to 705 Nm) with flexibility for future growth. The RWD six speed family is expected to improve both fuel economy and acceleration performance. As an example, the 6L80 is expected to improve fuel economy by as much as four percent, while improving 0-60 mph times by as much as seven percent when compared to the current four speed automatic that it replaces. This was accomplished by a wider overall ratio spread of 6.04:1 compared to the typical 4.0:1 for conventional four-speeds.
Baran, Jeff, Hendrickson, James, Solt, Michael
Fundamentals of Automotive All-Wheel Drive SystemsC030511/24/2003
This seminar provides an introduction to the fundamental concepts and evolution of passenger car and light truck 4x4/all-wheel drive (AWD) systems including the nomenclature utilized to describe these systems. Basic power transfer unit and transfer case design parameters, component application to system function, the future of AWD systems, and emerging technologies that may enable future systems are covered. This course is an excellent follow-up to the 98024-A Familiarization of Drivetrain Components seminar (which is designed for those who have limited experience with the total drivetrain). By attending this seminar, you will be able to: Identify front wheel drive and rear wheel drive vehicle architectures Identify part time, full time, and on demand all-wheel drive systems Explain the benefits of all-wheel drive over two-wheel drive Quantify all wheel drive traction and mobility benefits Describe auxiliary axle disconnect systems Explain basic vehicle dynamics performance and the effect of AWD on performance Identify couplers vs. biasing devices and their basic function Describe the differences between mechanical and electrical implementation in AWD systems Describe basic control strategies and logic Discuss advanced propulsion concepts and systems CEUs
All-Wheel Drive Systems ClassificationJ1952_200311 (Historical)11/17/2003
In this SAE Recommended Practice, attention will be given to passenger cars and light trucks (through Class III).
Drivetrain Standards Committee
Improved Differential Function for Avoiding Slippage of Motor Vehicles in a Muddy Trench2002-01-09883/4/2002
Vehicles such as trucks, buses and cars often get struck up in muddy trenches or in snow with one of wheels in the trench and the other on level ground. With an open differential, driver's effort to pull the vehicle out normally ends up with one wheel, which is rotating still going deeper into the trench. Until now Limited Slip Differentials (LSD), Locked Differentials and Viscous Coupling etc. have been used to overcome this difficulty but with limited success. Incorporating logic devices has developed a novel solution to this problem and the traction on the required wheel is achieved automatically. The system works independently of the conventional brakes.
Gill, S. S., Kalsi, N. S., Singh, Balraj, Singh, Nirmal, Singh, Neetu
Influencing Dynamic Handling Response with Manipulation of Advanced All Wheel Drive Systems2000-01-346012/4/2000
Trucks and sport utility class vehicles are established as choice of daily transportation in the US. A new breed of vehicles, commonly referred as “crossover vehicles”, based on passenger car derived platforms, are rapidly filling in the ranks between trucks and automobiles. Most of these vehicles are equipped with relatively sophisticated all wheel drive systems. This sophistication is necessary to fulfill the target mission of these vehicles, to provide an automatic and effortless all wheel drive capability while retaining refined on road comfort. Building on some of the existing systems and sensors, and integrating with other vehicle systems such as ABS, traction control and stability control systems, it is possible to enhance handling response by creating a moment along yaw axis. Pitch and roll movements can also be indirectly influenced. Further possibilities and enhancements will be feasible when drive by wire systems and active suspensions will become available. While most of these enhancements do not improve ultimate cornering and braking limits, they help average driver to recover or avoid critical maneuvers, improving safety and satisfaction of the users. This paper discusses several drivetrain-based approaches and concepts enhancing the on road capabilities of subject class vehicles.
Okcuoglu, Murat
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