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|15th November 2008, 06:24||#1|
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Join Date: May 2007
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Arjeplög - Where the world goes to test their ABS, TCS etc !
Welcome to Arjeplög.
In northern Sweden, Arjeplög has winter testing facility where Rolls Royce, Mercedes, BMW, Opel, Fiat, Porsche, Hyundai, Ferrari, other auto biggies and Bosch do a lot of ABS, stability control, and winter tire testing.
Arjeplög is a sleepy little town approximately one hour south of the Arctic Circle, which has its population double during testing every year, and ends up completely taken over by many of the car companies of the world during the Northern Hemisphere winter. Apart from being a pretty place, it is completely surrounded by lakes, which freeze over to provide icy conditions along with ample snow for consistent testing conditions.
I would like the special attention of the doubting Thomases w.r.t effectiveness of electronic systems like ABS, TCS etc.
Posted below is an article from Arjeplog Test Center » Articles
Last edited by kuttapan : 15th November 2008 at 06:26.
|15th November 2008, 06:25||#2|
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We're ringside in the winter car test capital of the world for an exclusive early insight into development of Ford's Territory AWD.
Snow glitters like diamond dust in the slanting sunlight of a blue-sky, Arcticwinter morning. The air of northern Sweden may be still today, but here it is not silent. A Falcon roars and slithers, its tyres heaving a sparkling blizzard behind. Scrabbling sideways on the ice at maybe 100km/h, Carl Liersch's driving looks good. Really good. One, two, three laps of the large circular track, we count. It's impossible to turn away. We all know Liersch's skill is the only thing keeping the car on the course. The Ford's Bosch stability system, a safety net woven from complex electronic and precision hydraulic systems, is switched off.
It can't last. And it doesn't. Now there's so much snow floating in the air it's difficult to see the far side of the circle. From somewhere over there comes the muffled sound, unmistakable, of car punching snow. Then frigid, minus-15-degreescentigrade silence. It takes 20 minutes of shovelling and shoving to extract the Falcon from the drift. It looks like a Falcon, at least. Right here and now, Arjeplog in February 2003, it's an E265 "attribute prototype". It's still a week before the Melbourne motor show announcement, by Ford Australia president Geoff Polites, that the E265 will be called the Territory when it reaches showrooms in the second quarter of 2004.
The body of Liersch's car was among the first BA Falcon "confirmation prototype" shells built at Ford's Broadmeadows plant way back in early 2001, more than a year ahead of that model's launch. Having served its purpose in this role, it was then passed to the E265 team. Territory all-wheel-drive hardware and front suspension was installed, and ballast added to simulate the Territory's mass, weight distribution, and centre of gravity. Then it was shipped to Europe.
Now the car is Carl Liersch's workplace, an office on 17-inch wheels. Liersch is a Bosch Australia application engineer. His job, along with the other specialists of the sizeable Bosch Australia team working in Sweden this winter, is to ensure Ford gets exactly the kind of stability program it wants for the Territory.
The winter car-testing capital of the world
There's no better place to do this job than Arjeplog, population 1800. Abundant ice has made this little town just south of the Arctic Circle the winter car-testing capital of the world. A picture postcard aerial view of the town in summertime shows it surrounded on three sides by large, clean, blue lakes. When winter cold freezes them solid enough to support cars, usually from December to March, Arjeplog booms. The largest local businesses are companies specialising in the preparation and grooming of made-to-order ice test tracks for car makers and automotive component suppliers. Arjeplog's population almost doubles as engineers, technicians, and test drivers move in. At the Silverhatten Hotel, where many of the car-test community congregate for lunch break, you are as likely to hear English, German, Italian, or Japanese being spoken as Swedish.
Since automotive component suppliers and car makers discovered Arjeplog's usefulness, more than 30 years ago, it has played a significant part in the development of many modern active safety systems. Bosch developed ABS brakes here in the '70s. In the same decade, the German giant worked on traction-control systems, which built on the useful ability of ABS to manipulate the brakes of individual wheels. From the mid '80s, Bosch did much of the development work on ESP here. And Arjeplog was the place chosen by Mercedes-Benz for the initial demonstration to the press of the first production-ready ESP system, developed in collaboration with Bosch, in March 1994.
We're in Arjeplog now because Ford Australia decided, back in 1999, that the Territory was going to need what Bosch had to offer. Especially the all-wheel-drive version. The E265 was not approved at this time. It wasn't until president Geoff Polites and two other Ford Australia executives successfully pitched the program to Detroit late in 2001 that the Territory had a green light.
By this time, Bosch Australia's preparation for the program was well advanced. The company had plenty of home-grown ABS brake expertise, but stability programs are much, much tougher technically. Promising people were picked out and packed off to Germany from 1999 to learn the ABC of ESP, DSC, and VDC. All of which, by the way, are synonymous.
From these emerged the key people of the all-wheel-drive Territory stability program development team. There are three of them. Alex Rule is the core software expert. Chris Wood is the system and logic genius. The third is Carl Liersch.
During his period of intensive technical training, Liersch participated in the development of different models from the Ford empire, including the current Mondeo. When the BA-based Territory attribute prototype arrived in Germany, it became his baby. It has been driven in Spain, France, and Belgium, but come December it's time to head for Sweden.
Liersch and the other Australians on Arjeplog assignment comprise just a fraction of the total Bosch contingent. There are between 200 and 250 Bosch people here, working on future products for a variety of car makers. They're easy to spot in this season's new-pattern, company-issue Arctic jackets.
On arrival in Arjeplog, I'm given one. So is photographer Helmut Mueller. Wouldn't want to be mistaken for media, would we? The camouflage value of the red-and-grey jacket is immense. Which is why Bosch takes security precautions with issuing them. Having met Ford Australia chassis development manager Alex de Vlugt and Territory vehicle dynamic development engineer Matt Reilly at Frankfurt, we've all flown on Bosch's pretty little Hawker Siddeley 800 bizjet direct to Arvidjaur, the nearest airport to Arjeplog, avoiding a tortuous sequence of scheduled commercial flights. The mission? This is to be the second-last step in Ford's signoff procedure of Bosch's work. The basic calibration developed here must endure a final round of validation and refinement testing in Australia before receiving final approval.
I learn all this after our arrival. The Bosch team are determined that before I venture outdoors, I must possess some basic understanding of their work. The lecture in a small conference room of the Silverhatten Hotel lasts most of the morning. They try hard to pitch it at a level a journalist can comprehend, but keeping up is tough.
The Bosch Australia people are particularly proud that the Territory all-wheel-drive will get the latest and most advanced version of their system, ESP 8. But before they get to this, a technological history lesson is required.
Traction control system
The tale begins with ABS brakes. Classic, stand-alone ABS compares vehicle speed with wheel speed, I'm told. A difference in the standard relationship between the two is slip. Around 15 percent slip usually gives maximum braking force, so the system's electronic slip controller attempts to keep it in this optimal zone. Optimal slip, however, can vary widely, depending on the friction of a particular driving surface. Dirt is especially tough. For the Territory, new logic has been written for improved gravel performance, I'm assured.
Clearly, it's going to take some pretty damned special hydraulic systems to do the job. Yes, indeed, according to Bosch. Hydraulic modelling is the key to making ABS work. Brake-fluid pressure and volume, and pad-friction values, are all important. Apparently Bosch has an entire department of hydraulic modellers working on this stuff, fiddling with maybe 10,000 parameters in any system.
It's possible to build on the foundation stone provided by ABS. The next step is to expand the system's ability. ABS can control slip at each wheel when braking, but is powerless to act when slip is caused by more torque than the tyres can cope with. With the addition of sensors and other hardware, plus the establishment of a communication and control link with the engine, you move to acceleration slip control. Or a TCS – traction control system – as the Bosch Australia folk prefer to call it.
With a sensor or sensors to check the rate of rotation of a vehicle's driveshaft or driveshafts, plus the existing ABS wheel-speed sensors, it becomes possible to figure out when torque is escaping as wheelspin. If a wheel is whirling much faster than the optimal traction slip threshold, there's been a loss of traction. Applying the brake of the uselessly spinning wheel will naturally divert the runaway torque to the opposite tyre, which obviously has greater traction because it's not spinning. In an all-wheeldrive application, like the Territory, the system can also apportion torque between front and rear axles, as well as left and right wheels.
But what if there's just too much torque for all four wheels to deal with? In this case it's only possible for effective action to be taken if there's some way for the system to cut torque. I learn from Bosch that the electronic throttle of the Territory's 4.0-litre, sixcylinder engine is not the main source of torque control. Nope, gross control of torque is achieved by cutting ignition or fuel, or both. This way the inertia of incoming air is least affected, which helps keep the engine's responses to the orders of the TCS computer sharp. The electronic throttle, apparently, is a tool of last resort.
Further additions to the system create something entirely new. ABS and TCS can control slipping or skidding in the longitudinal plane. A stability program – ESP, DSC, VDC – can deliver lateral slip control. And this is where things get really complicated. You guessed it; more sensors. A steeringangle sensor, a yaw-rate sensor, and a lateral-acceleration sensor provide the system's major inputs. Yaw is just another word for turn, so don't be afraid of it. These inputs build a picture of what the vehicle is actually doing, which can be compared with what the driver has asked for. Here the steering angle is again crucial, as is information on throttle opening or brake application. With appropriate software, which relies on logic I now realise is even more complex than I had imagined, the system is able to curtail sideways slip, be it understeer or oversteer. To do so it uses the torque reduction technology of TCS or the individual wheel braking ability of ABS, or both.
Ford wanted subtle, swift, early interventions, not gross, sluggish, late action
I'm experiencing Demtel déjŕ vu as my education advances. With a system as powerful and clever as a stability program, there's always more. The addition of extra functions is easy, and covering all the bases is difficult. Hill descent control, a driver-switched system to limit vehicle speed on steep descents, and a desirable feature on something like an all-wheel-drive Territory, is relatively simple to add.
Ford and Bosch agreed early on a general philosophical direction for the Territory system. Fun to drive is a Ford objective with the Territory, so they decided to install a two-stage systemdisablement switch. A short push disables torque reduction, a long push kills everything except ABS. When the system is active, Ford wanted subtle, swift, early interventions, not gross, sluggish, and late action. Arjeplog, the most testing, most extreme conditions the system will ever encounter, is the place to taste-test it.
Carl Liersch, with a few taps of the keyboard on the Toshiba Tecra laptop sturdily mounted in the passenger seat of his Territory attribute prototype, can add a little spice to the program. Then he can let de Vlugt or Reilly sample it. Luckily, unlike in cooking, a few more taps can take what was added out again. This way, the process of Bosch demonstrating to Ford that the stability system will be to their liking proceeds. We drive up the steep side of Galtis, the 700-metre-high ski hill just outside Arjeplog. De Vlugt, determined to test the Territory's traction to the limit, bogs in a deep snow drift just short of the summit. He's forced to turn around and take the snowploughed main road to the top. Matt Reilly drives down, checking some subtle alteration Liersch has made to the hill descent control.
The Arctic Circle
We drive north-west from Arjeplog, and stop at the Arctic Circle before heading to Norway. It's Sunday, and the country appears to be closed. I drive the car back into Sweden, on roads where the bitumen is often almost obscured by treacherous slush and ice. To either side are hills covered by pristine snow below low, dark, wind-shredded cloud. It's remote, empty, beautiful country. And it could easily kill you. It reminds me of the outback, in white instead of red.
"Would it be a real problem if I broke it," I ask de Vlugt and Liersch in the back seat, after we've been driving some time. "Well, yes, it would actually," de Vlugt tells me. "It's the only one we've got." Conscious of the responsibility, I ease off a little. Bosch's land-based facility at Skeut, outside Arjeplog, is the perfect place to experiment. Here, there are three traction-test hills with different grades. One wheel track is ice, the other bitumen, warmed from beneath. The Territory prototype climbs halfway up the steepest – 20 percent – then stops. With its TCS working furiously, it moves from rest, straight and steady, to the top. Then we give the ABS a workout on the adjacent chequerboard of ice and bitumen. The Ford stops hard, making the most of its brief grabs at the warmed black squares.
For DSC, the lake ice is perfect. There's a neat little handling track, not fast, but every corner is treacherous. There's a long, broad strip, where you can try coarse or fine steering inputs at relatively high speeds. It's unbelievably slippery. And there's the ice circle...
"Want to drive?" asks Liersch. Yes. It's a clue how little grip is available when the system can only deliver snail's pace acceleration when the throttle is floored. But the Ford goes where it's pointed.
"Try it with the system switched off," he insists. I've seen another ice novice spin the car a nanosecond after touching the accelerator pedal. It's a game of throttle control, I realise. Feather-light pressure on the pedal sets the Territory prototype sideways, and I manage the longest, semicontrolled, jogging-pace lose you can imagine. I make it maybe a quarter of the way around the ring.
"The system will work well anywhere if it works here," Liersch tells me. I believe it.
|15th November 2008, 11:47||#3|
Join Date: Nov 2008
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Its nice that people are testing in the worst conditions possible. That way we are safe no matter where . Could you just imagine driving around without tcs or abs on ice. man it wil be fun lol. the drifts you ould pull of man. Would love to become a test driver for a company .anyway isnt esp(electronic stability prgram) the most advanced system in offering for india ? or is there better ?
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