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. This article presents a novel approach to the control of modern torquevectoring differentials based on the concept of. Intelligent torque vectoring approach for electric vehicles. It is well known that rearwheel drive rwd vehicles are more fun to drive and faster in their reactions.
The system is able to generate a desired torque difference t between the wheels of the rear axle see fig. Mazda launches its first model with torque vectoring for. New torque vectoring electric differential toved electric differential represents advancement in electric vehicles technology along with the more traction control. Today a fellow track buddy porsche gt3 driver was asking me how the torque vectoring works in my gtr. Download pdf info publication number us20060025267a1. Awd torque vectoring differential prototype youtube. This maximises grip and sharpens handling, helping you round corners and over undulations in.
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. Wheel torque distribution criteria for electric vehicles with. 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. A special torquevectoringdifferential replaces the standard reardifferential. Torque vectoring technology is generally defined as a vehicles ability to vary the power to each wheel. 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.
Transport electrification is currently a priority for authorities, manufacturers, and research centers around the world. Ford focus rs torque vectoring control how it works. A torque vectoring differential requires an electronic monitoring system in addition to standard mechanical components. Torque vectoring tv has the objective to substitute the need of a mechanical differential, while improving the handling and response of the wheeled vehicle. Developers are increasingly focusing on torque management to improve longitudinal and lateral dynamics and to enhance the vehicles characteristics. Some even older vehicles have no torque differential at all. The torque vectoring controller is the electrical substitute of a mechanical differential, with the advantage of improving the stability and handling of the vehicle. Three case studies include two variants of a base case model. The design goals for a torque vectoring controller are good response behavior, high accuracy, and linear behavior of the car during high loads. Unfortunately, they are also less intuitive and harder to control because of their natural oversteering. Based upon a proven core design successfully demonstrated in 2004 comprising a novel epicyclic gear. 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. Development of an advanced torque vectoring control.
Torque vectoring is a handling feature so advanced that it seems to respond to your impulses even before you turn the steering wheel. Stability control and torque vectoring systems modified. Intelligent torque vectoring approach for electric vehicles with per. Torque vectoring for a formula student prototype springerlink. Design and simulation of a torque vectoring rear axle. Differential with torque vectoring capabilities us8329658b2 en 20050930. The sporting spirit that characterises a highperformance car can be observed in certain technical solutions. Development of torque vectoring differential control ecu. A discretetime controller design is proposed and the. 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. 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.
For the automotive industry, torque vectoring tv is a modern concept to enhance driving stability and safety whilst improving vehicle dynamics or the funtodrive. Originally developed for sports vehicles to avoid the need for a limited slip differential and other costly components, it is. 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. Classification and analysis of electricpowered lateral. 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. Due to the number of wheels that receive power, a front or rear wheel drive differential is less complex than an allwheel drive differential. As much as 100% of the available torque can be sent to an individual wheel with some setups. 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.
Pdf electric torque vectoring for electric vehicles. 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. Torquevectoring differentials tvds are one of the biggest advancements to improve vehicle handling dynamics in the 21 st century. Chapter7discusses real test drives, which demonstrate the performance improvements achieved with torque vectoring, as compared to an equal. The development of electric vehicles and the improvement of their functionalities are key elements in this strategy. Arylalkyl and heteroarylalkyl derivatives of cyclosporine a for the treatment and prevention of viral infection. To which i responded, there is no torque vectoring just a simple lsd in the rear and an open diff in the front. 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. Torque vectoring differential apparatus us8025603b2 en 20060818. Well, he directed me to this article from 2011 which states otherwise. Jun 06, 2017 new torque vectoring electric differential toved electric differential represents advancement in electric vehicles technology along with the more traction control. Study on torque vectoring differential for vehicle stability control via. 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. The torque vectoring differential strategies include superposition clutch, stationary clutch, fourwheel drive and electronic stability control.
As a result, there is a need for further research in emission reduction, efficiency improvement, or dynamic handling approaches. When one wheel starts rotating faster than the other, the spiralcut gears sort of jam against the case and axle gears. Torque vectoring differential putting added control into the hands of the driver, the rcf features an available lexus first torque vectoring differential. Torque vectoring is where in the differential can change the rotational speed of each wheel based on cornering. Pdf torque vectoring differentials tvds facilitate torque distribution to individual wheels, thus improving the vehicle dynamics. Features and technologies listed will not be available on all models. 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. 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. Torque vectoring electric differential linkedin slideshare. Functional schematic of the case study 4wd electric vehicle layout comprising one onboard.
Vehicle torque vectoring control university of waterloo. The electric differential provides the required torque for each driving wheel and allows different wheel speeds 6. Wheel torque distribution criteria for electric vehicles. Many older vehicles have a limited torque differential, which is a much less advanced version of torque vectoring. The basis of all ricardo concepts is the use of a actuator with a low torque. The torque vectoring differentials are implemented on an eightdof vehicle model and controlled using optimized fuzzybased controllers. On the other hand, however, the differential gear has a drawback that the. A special torque vectoring differential replaces the standard rear differential. A torque vectoring differential tvd system base on vehicle stability control is proposed to achieve additional torque steering for improving vehicle. A comparison on optimal torque vectoring strategies in. Torque vectoring function is achieved through an additional assembly comprising of the differential gear set and motor. The torquevectoring system uses sensors to help get power to the road in a meaningful way that limits under steer and wheel slippage. The traditional open differential is like a 1980s office drone.
The system is able to generate a desired torquedifference t between the wheels of the rear axle see fig. Study of torque vectoring for allwheeldrive vehicles. This electronic system tells the differential when and how to vary the torque. Results show that the proposed intelligent torque vectoring system is able to increase the efficiency of. Torque vectoring is a handling feature so advanced.
A tbd is architecturally identical to an open diff, but uses spiral or helical cut pinion gears. This paper focuses on this aspect and discusses the. Florian and vincent create the optimal controller by combining. 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. The limitedslip differential is like that obnoxious it guy down the hall, justifying its attitude and flaws by doing what. Torque vectoring differentials and their control webthesis. Ford tech features torque vectoring control ford australia. 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. A comparison on optimal torque vectoring strategies in overall. 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. Development and implementation of a torque vectoring algorithm for an innovative 4wd driveline for a highperformance vehicle. The torque vectoring differential of claim 16 wherein the first, second and third gear sets all provide unique gear ratios. Benefits of individual wheel torque control, or torquevectoring, in terms of vehicle dynamics behavior have been well documented in the literature. Torque vectoring is a vehiclecontrol system used for cornering and lateral movements, and also results in easier handling for the driver.
This work addresses the design of a torque vectoring system in an rear wheel driven formula student prototype. This thesis focuses on clutch type torque vectoring differentials and their control strategies, it dedicates to show effects of torque vectoring differential. Also known as the quaiffe or torque vectoring diff, the tbd is a different animal entirely from the clutchtype. 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. Based upon a proven core design successfully demonstrated in 2004 comprising a novel epicyclic gear arrangement, several variants have been propo. The automotive torque vectoring market is primarily driven by the increased demand for luxury and performance vehicles including suvs, crossovers, and offhighway vehicles. Intelligent torque vectoring approach for electric.
Development of torque vectoring differential control ecu 29 1. On slippery roads, the system can also help maintain directional control. Torque vectoring is a technology employed in automobile differentials. 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. Article information, pdf download for a comparison on optimal torque vectoring. Nov 20, 2015 torquevectoring differentials tvds are one of the biggest advancements to improve vehicle handling dynamics in the 21 st century. Torque vectoring differential apparatus us7491147b2 en 20060503. Its tied into an allnew electric power steering system. 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. Subarus 2015 wrx gets smarter with torque vectoring. Vehicle torque vectoring control ece 1635 april 6, 2015 christopher au moeed siddiqui yujie guo. Torque vectoring using a differential a differential, or diff, takes torque from the engine then distributes it between the powered wheels.
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. 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. 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. Its like an open differential, except that power isnt sent to the path of. The torque vectoring differential strategies include superposition. Torque vectoring control reacts to the road surface 100 times per second. The cage contains gearing that transfers the torque to the axle shafts while accommodating for variances in angular velocity between the axle shafts. Pdf a comparison on optimal torque vectoring strategies in overall. Ford tech features torque vectoring control ford philippines. Since this solution does not use friction components it is efficient and durable. In this paper, a comparison is made on different torque vectoring strategies. Pdf modelling and analysis of torque vectoring differential. This work tackles the design, implementation and testing of a torque vectoring algorithm to be implemented in a formula student prototype. It acts like a limited slip differential without the disadvantages.
A torque vectoring differential is presented in this paper. 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. As for performance, the torque vectoring is imperceptible but it definitely makes the car perform in a spirited manner on a twisty road. The front end hugs every corner for improved traction and handling when accelerating through corners. However, very few studies exist which analyze the individual wheel torque control integrated with vehicle efficiency considerations. 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.
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. 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. Using the braking system to imitate the effect of a torque vectoring differential, torque vectoring control steps in before wheel spin occurs. Development and implementation of a torque vectoring.
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