Super Handling-All Wheel Drive or SH-AWD is the fully automated, fully automated all-wheel drive system designed and engineered by Honda Motor Company. The company describes the SH-AWD as a "... system that provides cornering performance that responds faithfully to driver inputs, and exceptional vehicle stability.While in the world (after Mitsubishi AWC), the SH-AWD system incorporates a front- rear with torque distribution set independently to the left and right rear wheels to freely distribute optimal torque amounts to all four wheels according to driving conditions. "The system was announced in April 2004, and was first introduced in the North American market in 2005 model second generation Acura RL, and in Japan as the fourth generation Honda Legend.
As first applied in the Acura RL, the SH-AWD allows torque to be continuously distributed between the front and rear wheels of the front 70%/30% front rear 30%/70% rear, with up to 100% of the rear power being distributed to the left or right wheel outside to help cornering and dramatically reduce the understeer. For example, in a full-line throttle acceleration, RL is capable of distributing 40% of the torque to the rear wheels and 60% to the front wheels. In a difficult spin, the percentage of power distributed to the rear wheels, up to 100% of the rear wheel power can be distributed to a single rear wheel. This action will push the back of the corner, and help with the rudder, reduce the understeer and keep the car balanced and controlled. The effect can be likened to a rudder on a row boat where applying more power to one paddle can change the boat.
The SH-AWD all-wheel-drive system was praised by Popular Science as one of the best automotive innovations of 2004, and as part of a technologically equipped vehicle helping to get the 2005 "year" car from CNET. com.
Honda has since announced the evolution of SH-AWD using hybrid electric technology. In the 2012 announcement, the SH-AWD Sport Hybrid (Super Handling of All-Wheel Drive), replacing the mechanical drive shaft and coupling package with two 27 hp electric motors, one on each wheel that is not driven by a gasoline engine. The first two apps announced from the SH-AWD Hybrid Sport will be on the Acura RLX 2014 rear wheels, and on the new Acura NSX Concept front wheels.
Video SH-AWD
Development
At a very basic level, the SH-AWD system is a combination of Honda VTM-4 all-wheel-drive drive system and ATTS variable torque distribution system. Honda introduced the Active Torque Transfer System (ATTS) technology in the Honda Prelude Type SH 1997. Honda introduced the all-wheel-drive 4WD (VTM-4) all-wheel-drive system at the end of 2000 on the 2001 model Acura MDX sport utility vehicle (SUV ) and then on the 2003 Honda Pilot SUV.
The VTM-4 system is claimed to be different from other all-wheel-drive systems because of the "anticipation" decrease in the wheel, rather than waiting for the vehicle to feel the wheel slip, after a vehicle may have a problem. The VTM-4 system consists of a pair of computer-controlled wet grips in the rear axle that work together with the front wheels regardless of road conditions. At start-up, the VTM-4 system will send torque (power) from the front wheel to the rear wheels to complement the normal front-wheel drive mode. With all four wheels switched on start-up, regardless of the condition, more tire power is provided than the four-wheel drive rather than two front-wheel drive. In a dry place, this serves to reduce the front wheel steering wheel drive, and provides more front tire adhesion for cornering. In the rain, snow or mud, the power to the rear wheels moves the vehicle from the break with a minimum of wheels because the four tires work together to drive the car, not just the two front tires. VTM-4 is designed with special key mode to help when the vehicle is stuck in the snow. This lock mode automatically drives power to all four wheels at low speed. As speed increases, power to the rear wheels will decrease, and at 18 mph, the system will return to the front wheels.
The SH-AWD combines the ability of an automated VTM-4 all-wheel drive system with the ability to "transmit" torque capable of shifting the ATTS to the rear axle.
In the North American market, Honda introduced the original SH-AWD system introduced in late 2004 with the second generation Acura RL 2005. Two other SH-AWD variants were introduced in late 2006 in all the new Acura RDX 2007 and second generation Acura MDX Sport Utility Vehicles SUV 2007. At the end of 2008, an improved version of Acura RL SH-AWD was introduced in a significantly revised Mid-Model change (MMC) from Acura RL 2009. This enhanced version provided previous SH-AWD interventions (first gear vs seconds) and more precise use of the differential rear electromagnetic clutch system.
Yet another version of SH-AWD was introduced in late 2008 with fourth generation 2009 Acura TL. The Acura TL implementation of SH-AWD is actually mechanically more similar to the SH-AWD layout in Acura MDX and RDX where the above rear differentials are driven at a constant 1.7% faster than the front wheels, unlike Acura RL, which, since introduced in 2004, adds acceleration devices that can drive the rear wheels up to 5.7% faster than the front wheels.
In 2010 Acura RL remains the only SH-AWD configuration with a variable speed differential differential acceleration device. 2010 The new Acura ZDX four-door sport coupe introduced maintains the same mechanics of 1.7% fixed over rear differential configuration driven to other Acura-equipped SH-AWD vehicles
Acura announced in late 2008 that the 2010 Acura TL SH-AWD will be implemented with a six-speed manual transmission. The previous implementation of the SH-AWD has all been with a five-speed automatic transmission.
On July 20, 2009, Acura announced the Acura ZDX four-door sports coupe, equipped with a new six-speed automatic transmission and the SH-AWD. This will be the first time a six-speed automatic transmission will be mated to the SH-AWD, as well as being the first six-speed automatic transmission introduced in either Acura or Honda line up.
One week later, Acura announced a similar six-speed automatic transmission and SH-AWD with the 2010 Mid Model Change (MMC) update for the second generation Acura MDX.
In December 2010, Acura RL 2011 was announced with a Second Medium Model Change, featuring, among other things, a six-speed automatic transmission.
On November 30, 2011, as part of the publicity surrounding the Tokyo Auto Show 2011, Honda announced a new implementation of SH-AWD as part of "Earth Dreams Technology". The new SH-AWD electric hybrid will be based on all the new 3.5 L V-6 technology and three electric motors and lithium-ion batteries. The V-6 will be mated to a 30 kW electric motor that can operate independently of the V-6, unlike Honda's lighter IMA hybrid configuration. In addition, each rear wheel will have a 20 kW electric motor that will operate independently, various torques as a condition request. In turn, the electric motor will apply torque to the outside rear wheels, while the inner rear-wheel drive will drag, amplifying the SH-AWD effect. At the same time, the drag motor will act as a generator, delivering power to the outer wheel motor. If the lithium ion package becomes exhausted, the V-6 will drive the front electric motor as a generator to supply power to the rear wheels while also charging the battery. A prototype of this system is shown in a trial mule using the 8th generation of the North American version of the Honda Accord.
Maps SH-AWD
Function
The current SH-AWD configuration is all mated to a transverse engine, either a turbo-charge four-cylinder K-series engine in the RDX case, or a naturally aspirated V-6 version of the Honda J-Series engine. The engine is mated to a front-wheel-drive transaxle. There is no central difference. Transaxle is bolted to a torque transfer unit that rotates the central drive shaft that drives the rear differential unit. The rear differential is a T-shaped device. The power coming from the engine is transferred through the central hypo-tooth that provides power to each rear axle. Power for each shaft is modulated by an identical planet gear device and an electromagnetic coupling package that can vary the power side to side.
As mentioned earlier, the SH-AWD can vary the torque side to the side through the rear wheels. The ability to drive one of the rear wheels with greater force (remember the line boat analogy) is achieved through overdriving the rear wheels with respect to the front wheels. The Acura RL is designed with a set of third planetary gears and packaged clutch packs into what is called "Device Acceleration", which races in front of the rear differential unit. The Acceleration Tool allows torque to be passed to the rear wheels at a one to one ratio, but in cornering situations, the Acceleration Tool varies increasing the torque that is passed backward by up to 5%, depending on the cornering situation.
In early 2010, SH-AWD has been implemented by Acura in two similar configurations, but mechanically different, with and without Device Acceleration. More complex SH-AWD versions use the Acceleration Tool and can be found at:
2005-2008 Acura RL Sedan 2009-2010 Intermediate Change Model Acura RL Sedan 2011-2012 Mid-Range Acura RL Sedan Change Model
The less complex version of SH-AWD eliminates the Acceleration Tool and can be found at:
2007-2012 Acura RDX CUV
2007-TBD Acura MDX SUV
2009-TBD Acura TL SH-AWD Sedan
2010-TBD Acura ZDX SH-AWD Coupe Mobil Empat Pintu
The Acceleration Tool allows the rear wheels to be overdrive varied with respect to front wheel speeds up to 5.7%. Acceleration device in Acura RL is positioned in front of the rear differential. During normal steady driving, the Acceleration Device input shaft (from the engine) and the output shaft (to the rear differential) rotate at almost the same speed. In cornering situations, the output shaft rotates up to 5.7% faster than the input shaft, effectively speeding the rear wheels. The electromagnetic coupling package, based on the sensor input, will vary the torque delivered to the rear differential from side to side providing a constant and dynamic balancing of car handling characteristics.
The SH-AWD configuration without acceleration device overdrives the rear wheel at a constant 1.7% with respect to front wheel speed.
The acceleration device was first introduced in the flagship Acura RL sedan, and continues in the MMC version of the Acura RL sedan. This more complicated configuration seems to be unique among ACs with SH-AWD. This more complex RL configuration can be considered an exclusive proprietary vehicle feature, and is not specified for vehicles with lower price points. On the other hand, the new SH-AWD configuration without the Acceleration Tool could be a simpler and less sophisticated version due to the dynamics of the vehicle and the price point, or it could represent a new, smoother, less complex, and more reliable and more reliable standard for configuration SH-AWD. The rationale for the two different configurations has not been published by Acura.
SH-AWD in Acura RDX and Acura MDX use standard 90% power sharing forward and 10% backward. Like the units in RL, both can turn on the rear wheels with varying amounts of engine torque. Power division below the straight line, high speed acceleration varies from vehicle to vehicle. In addition, in cornering situations, depending on the balance and dynamics of a particular vehicle, the ratio of backward power transfer in the RDX and MDX is very different from the RL and TL sedans.
For example, in comparing RL to MDX, in hard cornering, most power transferred to the rear wheels for RL is 70%, whereas MDX is only 50%. In an efficient straight line voyage, different year models of RL can transfer from 70 to 80% to the front wheels, while MDX can transfer as much as 90% to the front wheels.
System integration
The SH-AWD technology is highly integrated with other systems and sensors implemented in Acura vehicles including:
3 or 4 channels (depend on model) Anti-lock Braking System (ABS)
4 channel Vehicle Stability Assist (VSA)
Electronic Brake Power Distribution (EBD)
Throttle control system Yaw Angle Sensor - Speed ​​sensor Steering Angle Sensor | G-Force lateral sensor
These systems and sensors all work together to improve vehicle handling, and safety.
Implementation
Acura RL
The second generation Acura RL sedan, introduced in late 2004 as the 2005 model, is the first production implementation of SH-AWD. It is the most mechanically complex, and probably the heaviest implementation of the SH-AWD. RL is powered by variable valve variables VTEC 3.5L 290Ã, and V-6 (2005-2008) or 3.7 L 300Ã, hp VTEC V-6 (2009-2010) transverse mounted with typical Honda way-car- car. In fact, RL uses a highly modified version of Honda Global Midsize, an existing version for the Honda Accord, Acura TSX and Acura TL. However, the front transaxle is directly coupled to the torque transfer unit. Two identical clutch/planetary giretes drive each rear wheel. The rear wheels are always overdrive with respect to front wheel speed. The acceleration device can alternately increase the rear wheel speed by up to 5.7%.
The 2005 and 2006 systems typically deliver 70% power to the front wheels and 30% backward under normal conditions but this ratio can retreat according to dynamic driving conditions. The brochure specification sections 2007-2008 show that this ratio changes to 80% -20%, and vice versa. This system can work because the clutch can slip in a state where the vehicle is spinning, thus allowing the rear and front wheels to turn at different rates around the curve. As mentioned above, the SH-AWD can take 100% smoothed power through the rear differential and different direct power to each wheel, up to 100% of that power to the outside rear wheels. Adding power to the outside rear wheels in turn has a steering effect on the vehicle that can greatly improve the dynamics of vehicle handling through oversteer reduction and more balanced handling. In limited circumstances, the vehicle can show a power oversteer, the more sporty rear-wheel-drive vehicle characteristics.
While the rear differential also acts like a limited slip differential in driving with passion, the SH-AWD is highly integrated into the Honda Vehicle Stability Assist (VSA) system and various onboard sensors that help keep the car under control in various situations.
RL 2009 is updated to have more aggressive intervention from SH-AWD to give the car more handling characteristics such as rear wheel.
Acura RDX
The Acura RDX was introduced in mid 2006 as a model car of 2007. The first generation Acura RDX is a small crossover utility vehicle, and features a simpler SH-AWD implementation than found in RL. RDX does not have Acceleration Tool found in Acura RL; otherwise the rear wheel is always overdrive with a speed of 1.7% higher than the front wheel. The RDX is distinguished by a unique 240 hp 2.3L turbo charged in a four-cylinder VTEC engine mounted in what is supposedly the unique version of the Honda Global Small Light Truck Platform, a different version of the platform used for the Honda CR. -V and Element Honda. Machines are also mounted transversely.
Acura MDX
The second-generation Acura MDX, introduced in late 2006 as a 2007 model, uses a simpler SH-AWD implementation than found in RL, the main difference being that unlike the RL 70 front 30 rear distributions, MDX offers the opposite of the backward 30 30 front distribution The MDX configuration is similar to the one in RDX because there is no Device Acceleration as found in RL. The rear wheels are always overdrive with a speed of 1.7% faster than the front wheels. The MDX is powered by a VTEC V-6 3.7L 300 engine mounted transversely in the version of the Honda Global Light Truck Platform Besar, a version used for the Honda Pilot, the Honda Ridgeline, the Honda Odyssey, and the 2010 Acura ZDX. As can be seen below, the vehicle dynamics of the Acura MDX require different operating parameters.
Acura TL
The fourth generation Acura TL, introduced in late 2008 as a 2009 model has two main trim levels, front-wheel-drive versions, and upscale SH-AWD versions. Similar to the Acura RL layout, the Acura SH-AWD TL features a 3.7L 305Ã, hp VTEC V-6, front engine mounted across the Global Midsize Platform. The 2009 model uses a five-speed automatic transmission, but Acura also promises a new six-speed manual transmission for the 2010 model year. It remains to be seen if the 2010 model will also feature a new six-speed automatic transmission announced in the Acura ZDX prototype announced in April 2009 New York Auto Show. Unlike the Acura RL, the SH-AWD TL does not have an Acceleration Device.
Acura TLX
The Acura TLX was introduced in April 2014 at the New York International Auto Show .
Acura ZDX
The first generation Acura ZDX was announced on April 8, 2009 at the New York Auto Show as a 2010 model, which is scheduled to be introduced at the end of Autumn 2009 as the all new prototype concept car, which is billed as a four-door luxury sport coupe. The Acura ZDX goes on sale December 15, 2009. The car is powered by all aluminum-3.7L 300 hp, 270 lbs-ft of torque VTEC V-6, mated to an all-new 6-speed automatic transmission with Sequential SportShift and Super Handling All-Wheel Drive. The V-6 seems to be mechanically similar to the Acura MDX V-6. The Acura ZDX SH-AWD implementation description seems very similar to the Acura MDX SH-AWD implementation.
See also
- 4Matic - four wheel drive system from Mercedes-Benz
- ATTESA - Nissan's four wheel drive system
- xDrive - four wheel drive for BMW
- Quattro (four wheel drive system) - four wheel drive system from Audi
- S-AWC - four wheel drive system from Mitsubishi Motors
- Saab XWD - four wheel drive system from Saab
- 4motion - four wheel drive system from Volkswagen
- All-Trac - Toyota's four wheel drive system
- Symmetrical All Wheel Drive - four wheel drive system from Subaru
References
External links
- http://www.acura.com/index.aspx?initPath=RDX_Learn_FeaturesOptions_Performance_SHAWD_SHAWDOverview
Source of the article : Wikipedia
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