Since there is a differential involved and the entire system is. With the vector drive rear axle transmission, zf generates such a torque vectoring system at the rear axle. Torque vectoring is a vehiclecontrol system used for cornering and lateral movements, and also results in easier handling for the driver. Electronic control torque vectoring axle de102006025062a1 en 20060530. Fords torque vectoring control, introduced to north american buyers on the 2012 focus, is an electronic solution to wheel slippage. Differential with torque vectoring capabilities wo2007022230a2 en 20050816.
Oct 28, 2015 angle in combination with torque vectoring on the rear axle, the diameter of the turning circle of the advanced urban vehicle is reduced to less than 6. Vector drive distributes the input power in a continuously variable manner between the rear wheels. Due to their high cost and additional weight, torque vectoring transmissions have not yet found application in electric vehicles. Torque vectoring for improved driving market my article. The vector drive rear axle transmission springerlink. A uturn, in other words a turning maneuver of 180 degrees, is possible with no difficulty on a standard twolane road. By distributing the input torque individually onto either the left or right wheel, the. I was reading about the lexus rcf and how it has a torque vectoring differential and how this differential has the ability to put more torque on the outer turning wheels rather than on the inside wheels which seems to be a common differential issue and a problem engineers have had difficulty staying within cost containment controls. Zf is one of the largest automotive suppliers worldwide. On an awd vehicle torque vectoring only differs from esc system in software i.
A discretetime controller design is proposed and the. Zf 9speed automatic transmission for chrysler and dodge cars. Developers are increasingly focusing on torque management to improve longitudinal and lateral dynamics and to enhance the vehicles characteristics. To understand how torque vectoring works, it is first necessary to look at the function of the mechanical differential in detail. In fourwheel drive vehicles in particular, it is no longer simply a matter of distributing torque to the individual axles but also to the individual wheels. You could also have a pure battery electric vehicle with two etwinsters and 4wheel drive.
Pdf elektromechanisches torquevectoring mit aktivem. A torque vectoring differential apparatus disposed in a vehicle powertrain includes an engine, transmission, and a torque vectoring differential. Automotive supplier zf has created a new torque vectoring rear axle drive system that has been designed to distribute drive torque individually between a cars rear wheels. The schaeffler eaxle configurator schaeffler symposium 2018. Benefits of individual wheel torque control, or torquevectoring, in terms of vehicle dynamics behavior have been well documented in the literature. Further advantages are offered by torque vectoring systems, such as the zf vector drive rear axle drive unit. Zf35 code n19 trans zf4hp18 saab 9000 year engine dia hub spl pilot mount pilot center to bolt center stall 1995 10 1516 1. Torque vectoring usually refers to the ability to actively control how an engines power is distributed between a vehicles wheels typically between two wheels on the same axle, in order to help improve vehicle. A 5% improvement in fuel economy is being promised by a new generation of 11speed tripleclutch. Torque vectoring is a method used to enhance the on road handling and performance during cornering by altering the distribution of torque between the left and right rear wheels. Known as torque vectoring through braking known as xds in volkswagen group cars, the system brakes the inside wheel during a turn. Designed to help the front wheels grip and steer better in corners.
The side gear outputs are controlled to distribute torque from the torque and speed from the input member to the individual. Us7491147b2 torque vectoring differential apparatus. Zf unveiled the worlds first ninespeed transverse automatic transmission in june 2011, starting production in 20. The future of gearbox technology tripleclutch transmissions and more we explain the car tech. Well, some systems do not work offthrottle and this is where that brakebased torque vectoring comes in handy. Oct 01, 2009 german transmission and driveline company zf has also developed a torquevectoring system, called vector driveand its ready for volume production in allwheel and rearwheel drive vehicles. Nov 20, 2015 so what are the disadvantages of a torque vectoring active differential. The different concepts of individual torque distribution will be described and their characteristics will be stated. More electric axles on the way a look at the tech your. A tbd is architecturally identical to an open diff, but uses spiral or helical cut pinion gears. Lexus rcf torque vectoring differential, how does it work. Zf is a global leader in driveline and chassis technology as well as active and passive safety technology. Torque vectoring transmissions are used today in select top model cars and sports cars with combustion engines. This system gives more power to the outher wheel in a curve to make the car more agile for more information visit.
Mar 24, 2016 the technical solution from gkn driveline also mentions torque vectoring capabilities, while zf does not mention this facility. The term torque vectoring describes the active generation of a vehicle yaw. A torque vectoring differential acts very similarly to an open differential, except the axle shafts have planetary gearsets and clutch packs which allow them to lock up with the differential. This will increase the life and performance of the transmission and wont be found in used or rebuilt units. Electric vehicle, vehicle performance, braking, traction control, european union 1 introduction. Leaving aside the lock values and the internal friction, the differential distributes the input. Torque vectoring allows the torque produced by the drive to be dynamically distributed to all wheels of the vehicle. Zf annually invests about six percent of its sales in research and development ensuring continued success through the design and engineering of innovative technologies. Torque vectoring is a phrase you may have heard while researching your next car, but what is it. That, well cover active torquevectoring systems specifically brakebased systems vs. Torque vectoring for electric vehicles with individually. Design and analysis of a new torque vectoring system with a. The starting point in this respect is the zf concept of the electric. For the automotive industry, torque vectoring tv is a modern concept to enhance driving stability and safety whilst improving vehicle dynamics or the funtodrive.
Gear unit for guiding a drive torque from a drive shaft to two drive shafts. Its called torque vectoring, and its a system that enables the instantaneous and seamless distribution of torque to one specific wheel at a time. F11 year engine dia hub spl pilot mount pilot center to bolt center stall 199197 10 781. With the torque vectoring rear differential unit zf vectordrive zf friedrichshafen developed an intelligent actuator for control of driving dynamics to improve agility, traction and safety. The active edrive is thus born from the purely electric axle drive and, based on current vehicle tests and investigations, this represents a mile stone in. More electric axles on the way a look at the tech your next.
Oct 15, 2014 torque vectoring transmissions are used today in select top model cars and sports cars with combustion engines. Torque vectoring function is achieved through an additional assembly comprising of the differential gear set and motor. By adopting a torque vectoring mechanism, which independently distributes torque to the left and right rear wheels according to driving conditions, the dynamic torque vectoring awd system enables the driver to steer the vehicle exactly as intended. If the eps were to fail, this could be compensated for in a targeted fashion with the assistance of the akc or torque vectoring, in order to safely steer the vehicle to the side of the road in an emergency situation. Torque vectoring is a technology employed in automobile differentials. German transmission and driveline company zf has also developed a torquevectoring system, called vector driveand its ready for volume production in allwheel and rearwheel drive vehicles. German transmission and driveline company zf has also developed a torquevectoring system, called vector driveand its ready for volume production in all. It includes the growth rate of the global automotive torque vectoring systems market for the estimated period. Torquevectoring can be used to control the vehicle while braking only the. Simulation derives a pure drag torque related saving potential of 5. Torque vectoring adds a lot of degrees of freedom and intelligent responses to support what the driver wants. The automotive torque vectoring market is projected to grow at a cagr of 20. The new dynamic torque vectoring awd system is used in gasoline engine vehicles. Global automotive torque vectoring systems market trends 2019 borg warner, jtekt, gkn, zf, rimac, mitsubishi, ricardo, the timken company, prodrive june 15, 2019 4 min read.
A differential transfers engine torque to the wheels. Zfs new torque vectoring rear axle motor authority. Torque vectoring offers the possibility to actively control the yaw moment around the vehicles vertical axis and therefore improves the vehicle handling and compensates for potential understeering tendency. The automotive torque vectoring market is primarily driven by the increased demand for luxury and performance vehicles including suvs, crossovers, and offhighway vehicles. Lexus rcf torque vectoring differential, how does it. Since this solution does not use friction components it is efficient and durable. For tv, frontrear torque vectoring is modelled by distributing torques frontrear by a ca that allocates longitudinal forces in proportion to the normal load on the axle 8, found to be the optimal distribution 4.
This paper focuses on this aspect and discusses the. Further advantages are offered by torque vectoring systems. When one wheel starts rotating faster than the other, the spiralcut gears sort of jam against the case and axle gears. Torque vectoring technology is generally defined as a vehicles ability to vary the power to each wheel. A torque vectoring differential is presented in this paper.
Esc activates brakes only after sensors have detected that vehicle has lost grip. The transmissions are stopstart, hybrid, and allwheeldrive capable. Development of torque vectoring differential control ecu. You actually feel like a better driver because of the way the car responds. Us7238140b2 differential with torque vectoring capabilities. The basis of all ricardo concepts is the use of a actuator with a low torque. Torque vectoring for drivetrain systems granzow major. By controlling the power across the axle more effectively, the car is able to corner with more grip and turn into a bend. The aim of the researchers was, thus, to optimize the transmission for small vehicles with electric drives. Apr 22, 2014 torque vectoring offers the possibility to actively control the yaw moment around the vehicles vertical axis and therefore improves the vehicle handling and compensates for potential understeering tendency. Also known as the quaiffe or torque vectoring diff, the tbd is a different animal entirely from the clutchtype. Put simply, its a computercontrolled system to distribute an engines power across the left and right sides of a car. The electromechanical torque vectoring system can be combined with both the coaxial and parallel axis drive concepts described above. The paper is aimed at a comprehensive revision of the.
There are several all wheel drive systems that can regulate the torque that is sent to the wheels but these systems do this to maintain traction on various road surfaces. Every zf reman transmission is updated to include all technical updates from the original manufacturing factory. The torque vectoring differential includes a bevel gear differential assembly having a carrier input and side gear outputs. Marco gadola 1 and daniel chindamo 1, 1department of industrial and mechanical engineering, automotive group, university of brescia, i25123 brescia, italy. Most recentmodel allwheel drive vehicles cars and suvs already come with some kind of computermanaged system in order to boost fuel efficiency. The torque vectoring hardware units produced by gkn driveline will be supplied to system leader zf, who is responsible for the final assembly of the system and the supply of the electric motors.
Pdf electric torque vectoring for electric vehicles. Unlike a mechanical limited slip differential, which focuses on two wheels only and induces an artificial steering feel, the torque vectoring control encompasses all 4 wheels. Torque vectoring transmission for electric vehicles. The design goals for a torque vectoring controller are good response behavior, high accuracy, and linear behavior of the car during high loads. Different torque vectoring differential tvd patents have been revealed by car companies and suppliers, such as ford, zf, and honda recently. When one wheel starts rotating faster than the other, the. With more convenience and safety, the central control unit also paves the way for autonomous driving. Goaldirected utilization of active torque distribution to the four drive wheels has become increasingly important in the last few years, especially with a view to improving both driving dynamics and traction. Vehicle torque vectoring control ece 1635 april 6, 2015 christopher au moeed siddiqui yujie guo. Florian and vincent create the optimal controller by combining. The global report summarizes by providing the estimated development of the automotive torque vectoring systems market in the upcoming period.
The zfdisconnect system achieves an overall reduction of 4. This paper describes how such a rear axle torque vectoring system can be. Global automotive torque vectoring systems market trends 2019. Factory trained technicians assemble the unit and sub assemblies. Support from the rear this driver assistance function is supported by an allelectric rearwheel drive, which enables torque vectoring in other words distributing the drive force transversely to each individual wheel. However, very few studies exist which analyze the individual wheel torque control integrated with vehicle efficiency considerations. Feb 01, 2015 a torque vectoring differential acts very similarly to an open differential, except the axle shafts have planetary gearsets and clutch packs which allow them to lock up with the differential. The concept vehicle shows zfs expertise after the acquisition of trw maneuverability, emobility, cloud connectivity, and. The trending automotive torque vectoring systems report represents a comprehensive study of the global automotive torque vectoring systems market. Evaluation of optimal yaw rate reference for electric. Chapter7discusses real test drives, which demonstrate the performance improvements achieved with torque vectoring, as compared to an equal. With the torque vectoring rear differential unit zf vectordrive zffriedrichshafen developed an intelligent actuator for control of driving dynamics to improve agility, traction and safety. Pdf development of an advanced torque vectoring control.
Pdf a twopassenger, allwheeldrive urban electric vehicle auto21ev with four directdrive inwheel motors has been designed and developed at the. This method of power transfer has recently become popular in allwheel drive vehicles. Setting attractive trends for future mobility advanced urban vehicle. Pdf the level of electric recuperation of rear wheel drive electric vehicles and. Torque vectoring differential explained automotive videos. Equipped with torque vectoring control, the pilots system can send up to 70 percent of the torque to the rear wheels and 100 percent of that torque to either the left or right rear wheel. As the inside is braked, more power is sent to the outside wheel mimicking the rotational effect a torque vectoring differential applies to a car known as yaw. Torque vectoring technology provides the differential with the ability to vary the torque to each wheel. The technical solution from gkn driveline also mentions torque vectoring capabilities, while zf does not mention this facility. Global automotive torque vectoring systems market trends. Torque vectoring for drivetrain systems wiley online library. New dynamic torque vectoring awd and efour 4wd systems. Here the torque is distributed variably and asymmetrically to the left and right wheels on the rear axle. For example, if the brakes fail, the mstars axle is able to safely decelerate the vehicle using its generator function.
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