Stability control and torque vectoring systems modified. Development of torque vectoring differential control ecu 29 1. Wheel torque distribution criteria for electric vehicles with. The design goals for a torque vectoring controller are good response behavior, high accuracy, and linear behavior of the car during high loads. Wheel torque distribution criteria for electric vehicles. Testing of a torque vectoring controller for a formula. Ford tech features torque vectoring control ford philippines.
When one wheel starts rotating faster than the other, the spiralcut gears sort of jam against the case and axle gears. The system is able to generate a desired torquedifference t between the wheels of the rear axle see fig. Ford focus rs torque vectoring control how it works. Features and technologies listed will not be available on all models. This electronic system tells the differential when and how to vary the torque. However, very few studies exist which analyze the individual wheel torque control integrated with vehicle efficiency considerations. Us7238140b2 differential with torque vectoring capabilities. A differential for delivering vectored torque to left and right axle shafts that rotate about an axis includes a cage which rotates about the axis as a consequence of torque applied to it. Development and implementation of a torque vectoring algorithm for an innovative 4wd driveline for a highperformance vehicle. Downloaded from sae international by university of waterloo, tuesday, march 14. Compared to an open passive differential, a torquevectoring differential can actively regulate torque distribution between a vehicles wheels typically rear to significantly improve cornering performance. New torque vectoring electric differential toved electric differential represents advancement in electric vehicles technology along with the more traction control.
Originally developed for sports vehicles to avoid the need for a limited slip differential and other costly components, it is. Vehicle torque vectoring control university of waterloo. The electric differential provides the required torque for each driving wheel and allows different wheel speeds 6. Different solutions of clutch type torque vectoring differential and their layout schemes, characteristics outputs on both axles, torque difference between two outputs, clutch torque, speed difference, etc and working principles will. 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 housing, thus altering the amount of torque sent to each wheel. Vehicle torque vectoring control ece 1635 april 6, 2015 christopher au moeed siddiqui yujie guo. The torquevectoring drive also acts like a positivetraction or locking differential on dry or uneven traction startups, with torque going to the wheel with higher friction potential.
This paper focuses on this aspect and discusses the. As a result, there is a need for further research in emission reduction, efficiency improvement, or dynamic handling approaches. The torque vectoring differential of claim 17 wherein when the second gear set is selected, the first drive axle rotates around 20% faster than the second drive axle. Awd torque vectoring differential prototype youtube. We are writing about mazdas first torque vectoring solution, which has been designed to provide a higher level of comfort for the occupants of its models. Article information, pdf download for a comparison on optimal torque vectoring. A comparison on optimal torque vectoring strategies in overall.
Study of torque vectoring for allwheeldrive vehicles. Pdf electric torque vectoring for electric vehicles. Unfortunately, they are also less intuitive and harder to control because of their natural oversteering. Arylalkyl and heteroarylalkyl derivatives of cyclosporine a for the treatment and prevention of viral infection. In this paper, a comparison is made on different torque vectoring strategies. The limitedslip differential is like that obnoxious it guy down the hall, justifying its attitude and flaws by doing what. Jul 14, 2015 this prototype is a success to put more torque on the wanted wheels, but is a failure to make an awd transmission strong enough for the modified motor. This work addresses the design of a torque vectoring system in an rear wheel driven formula student prototype. The torque vectoring differential strategies include superposition clutch, stationary clutch, fourwheel drive and electronic stability control. Subarus 2015 wrx gets smarter with torque vectoring. Torque vectoring differential putting added control into the hands of the driver, the rcf features an available lexus first torque vectoring differential. Oct 01, 2009 the torque vectoring drive also acts like a positivetraction or locking differential on dry or uneven traction startups, with torque going to the wheel with higher friction potential.
On slippery roads, the system can also help maintain directional control. 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. 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. Some even older vehicles have no torque differential at all. The torque vectoring differential strategies include superposition. Based upon a proven core design successfully demonstrated in 2004 comprising a novel epicyclic gear arrangement, several variants have been propo. A torque vectoring differential tvd system base on vehicle stability control is proposed to achieve additional torque steering for improving vehicle.
This article presents a novel approach to the control of modern torquevectoring differentials based on the concept of. An optimal torque vectoring control for vehicle applications via realtime constraints dhanaraja kasinathan, alireza kasaiezadeh,andy wong, amir khajepour, shihken chen, and bakhtiar litkouhi abstracta generalized integrated control strategy for vehicle dynamics using an optimal torque vectoring control approach is extended in this paper. Functional schematic of the case study 4wd electric vehicle layout comprising one onboard. Due to the number of wheels that receive power, a front or rear wheel drive differential is less complex than an allwheel drive differential. Torque vectoring function is achieved through an additional assembly comprising of the differential gear set and motor. This system can only transfer one hundred percent of power between the front and rear wheel axles, which can be unhelpful in certain situations, particularly offroad. Torque vectoring control reacts to the road surface 100 times per second. For the automotive industry, torque vectoring tv is a modern concept to enhance driving stability and safety whilst improving vehicle dynamics or the funtodrive. An electricpowered lateral torque vectoring differential utilizes the output torque of an electric motor for generating the torque difference between the right and the left wheels. This work tackles the design, implementation and testing of a torque vectoring algorithm to be implemented in a formula student prototype. Torque vectoring is a technology employed in automobile differentials.
This thesis focuses on clutch type torque vectoring differentials and their control strategies, it dedicates to show effects of torque vectoring differential. Us20060025267a1 differential with torque vectoring. Well, he directed me to this article from 2011 which states otherwise. The torque vectoring differentials are implemented on an eightdof vehicle model and controlled using optimized fuzzybased controllers. Jun 06, 2017 new torque vectoring electric differential toved electric differential represents advancement in electric vehicles technology along with the more traction control. The basis of all ricardo concepts is the use of a actuator with a low torque. Using the braking system to imitate the effect of a torque vectoring differential, torque vectoring control steps in before wheel spin occurs. Torque vectoring is a handling feature so advanced that it seems to respond to your impulses even before you turn the steering wheel.
This prototype is a success to put more torque on the wanted wheels, but is a failure to make an awd transmission strong enough for the modified motor. Transport electrification is currently a priority for authorities, manufacturers, and research centers around the world. A comparison on optimal torque vectoring strategies in. Differential with torque vectoring capabilities us8329658b2 en 20050930. Based upon a proven core design successfully demonstrated in 2004 comprising a novel epicyclic gear. Developers are increasingly focusing on torque management to improve longitudinal and lateral dynamics and to enhance the vehicles characteristics. As for performance, the torque vectoring is imperceptible but it definitely makes the car perform in a spirited manner on a twisty road. The system is able to generate a desired torque difference t between the wheels of the rear axle see fig. Download pdf info publication number us20060025267a1. With torque vectoring control, the outside wheel in a turn is given the majority of the engines torque at the moment of a turn, while the vehicles brakes are engaged on the inside wheel, creating better grip and a sort of slingshot forward through the turn.
Different solutions of clutch type torque vectoring differential and their layout schemes, characteristics outputs on both axles, torque difference between two outputs, clutch torque, speed difference, etc and working principles will be discussed using velocity diagrams. 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. 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. Torque vectoring differentials and their control webthesis. The development of electric vehicles and the improvement of their functionalities are key elements in this strategy.
Pdf a comparison on optimal torque vectoring strategies in overall. The automotive torque vectoring market is projected to grow at a cagr of 20. Mazda launches its first model with torque vectoring for. A discretetime controller design is proposed and the. Torque vectoring technology is generally defined as a vehicles ability to vary the power to each wheel. Pdf torque vectoring differentials tvds facilitate torque distribution to individual wheels, thus improving the vehicle dynamics. Florian and vincent create the optimal controller by combining. A tbd is architecturally identical to an open diff, but uses spiral or helical cut pinion gears. Today a fellow track buddy porsche gt3 driver was asking me how the torque vectoring works in my gtr.
An electricpowered lateral torquevectoring differential utilizes the output torque of an electric motor for generating the torque difference between the right and the left wheels. Its tied into an allnew electric power steering system. Torque vectoring using a differential a differential, or diff, takes torque from the engine then distributes it between the powered wheels. The automotive torque vectoring market is primarily driven by the increased demand for luxury and performance vehicles including suvs, crossovers, and offhighway vehicles. Design and simulation of a torque vectoring rear axle. Torque vectoring tv has the objective to substitute the need of a mechanical differential, while improving the handling and response of the wheeled vehicle. Also known as the quaiffe or torque vectoring diff, the tbd is a different animal entirely from the clutchtype. The cage contains gearing that transfers the torque to the axle shafts while accommodating for variances in angular velocity between the axle shafts. A special torquevectoringdifferential replaces the standard reardifferential. Development of an advanced torque vectoring control. Torque vectoring is a vehiclecontrol system used for cornering and lateral movements, and also results in easier handling for the driver. Intelligent torque vectoring approach for electric vehicles.
With three unique modesslalom, track and standardthis system can direct power to the outside rear wheel when cornering, putting power to the ground more effectively while also helping to. Ford tech features torque vectoring control ford australia. The torquevectoring system uses sensors to help get power to the road in a meaningful way that limits under steer and wheel slippage. Introduction generally, cars have differential gears in driving wheels, and the differential gears absorb a speed difference between inner and outer wheels during turning so that smooth turning can be realized. It is well known that rearwheel drive rwd vehicles are more fun to drive and faster in their reactions. Chapter7discusses real test drives, which demonstrate the performance improvements achieved with torque vectoring, as compared to an equal. Torque vectoring electric differential linkedin slideshare. Torque vectoring differential apparatus us7491147b2 en 20060503. Classification and analysis of electricpowered lateral. Control when you need it torque vectoring control increases traction in the direction you want to travel and improves the steering ability of the inside tire.
Three case studies include two variants of a base case model. 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. Since this solution does not use friction components it is efficient and durable. Nov 20, 2015 torquevectoring differentials tvds are one of the biggest advancements to improve vehicle handling dynamics in the 21 st century. Torque vectoring for a formula student prototype springerlink. Dec 21, 2017 torque vectoring tv has the objective to substitute the need of a mechanical differential, while improving the handling and response of the wheeled vehicle. Torque vectoring differential apparatus us8025603b2 en 20060818. On the other hand, however, the differential gear has a drawback that the. Many older vehicles have a limited torque differential, which is a much less advanced version of torque vectoring. The traditional open differential is like a 1980s office drone. Intelligent torque vectoring approach for electric vehicles with per. A torque vectoring differential requires an electronic monitoring system in addition to standard mechanical components. The power distribution on the rear wheels is the simplest example of that. As much as 100% of the available torque can be sent to an individual wheel with some setups.
The torque vectoring controller is the electrical substitute of a mechanical differential, with the advantage of improving the stability and handling of the vehicle. Intelligent torque vectoring approach for electric. Study on torque vectoring differential for vehicle stability control via. Using this information, it balances the amount of power delivered to each of the two front wheels. Results show that the proposed intelligent torque vectoring system is able to increase the efficiency of. Light brake force is applied to the front inside wheel as soon as it begins to lose grip, sending more engine torque to the outside wheel that has more grip. Torquevectoring differentials tvds are one of the biggest advancements to improve vehicle handling dynamics in the 21 st century. This paper describes the process and simulation tool chain applied to the design for production of a rear axle with a variable torque biasing capability. Dec, 20 ford calls its front axle torque vectoring system an electronic differential, a term used to explain its primary function of limiting inside wheelspin while cornering and maximizing traction. The torque vectoring differential of claim 16 wherein the first, second and third gear sets all provide unique gear ratios. Torque vectoring is where in the differential can change the rotational speed of each wheel based on cornering. Torque vectoring is a handling feature so advanced. Pdf modelling and analysis of torque vectoring differential. To which i responded, there is no torque vectoring just a simple lsd in the rear and an open diff in the front.
Development of torque vectoring differential control ecu. Ford calls its front axle torque vectoring system an electronic differential, a term used to explain its primary function of limiting inside wheelspin while cornering and maximizing traction. This maximises grip and sharpens handling, helping you round corners and over undulations in. A torque vectoring differential is presented in this paper. Its like an open differential, except that power isnt sent to the path of. The front end hugs every corner for improved traction and handling when accelerating through corners. Most conventional cars have an open diff, meaning up to 100 per cent of the engines power can go to either wheel, following the path of least resistance. A special torque vectoring differential replaces the standard rear differential. Development and implementation of a torque vectoring. Benefits of individual wheel torque control, or torquevectoring, in terms of vehicle dynamics behavior have been well documented in the literature.