#trackday #driverslegion #AIA #29NOV14
Google Self-Driving Car on City Streets
The end of driving and self pleasure? Or a necessary evil for the future of safety.
Article from Google.
Jaywalking pedestrians. Cars lurching out of hidden driveways. Double-parked delivery trucks blocking your lane and your view. At a busy time of day, a typical city street can leave even experienced drivers sweaty-palmed and irritable. We all dream of a world in which city centers are freed of congestion from cars circling for parking (PDF) and have fewer intersections made dangerous by distracted drivers. That’s why over the last year we’ve shifted the focus of the Google self-driving car project onto mastering city street driving.
Since our last update, we’ve logged thousands of miles on the streets of our hometown of Mountain View, Calif. A mile of city driving is much more complex than a mile of freeway driving, with hundreds of different objects moving according to different rules of the road in a small area. We’ve improved our software so it can detect hundreds of distinct objects simultaneously—pedestrians, buses, a stop sign held up by a crossing guard, or a cyclist making gestures that indicate a possible turn. A self-driving vehicle can pay attention to all of these things in a way that a human physically can’t—and it never gets tired or distracted.
Here’s a video showing how our vehicle navigates some common scenarios near the Googleplex:
As it turns out, what looks chaotic and random on a city street to the human eye is actually fairly predictable to a computer. As we’ve encountered thousands of different situations, we’ve built software models of what to expect, from the likely (a car stopping at a red light) to the unlikely (blowing through it). We still have lots of problems to solve, including teaching the car to drive more streets in Mountain View before we tackle another town, but thousands of situations on city streets that would have stumped us two years ago can now be navigated autonomously.
Our vehicles have now logged nearly 700,000 autonomous miles, and with every passing mile we’re growing more optimistic that we’re heading toward an achievable goal—a vehicle that operates fully without human intervention.
Article from Google.
Jaywalking pedestrians. Cars lurching out of hidden driveways. Double-parked delivery trucks blocking your lane and your view. At a busy time of day, a typical city street can leave even experienced drivers sweaty-palmed and irritable. We all dream of a world in which city centers are freed of congestion from cars circling for parking (PDF) and have fewer intersections made dangerous by distracted drivers. That’s why over the last year we’ve shifted the focus of the Google self-driving car project onto mastering city street driving.
Here’s a video showing how our vehicle navigates some common scenarios near the Googleplex:
As it turns out, what looks chaotic and random on a city street to the human eye is actually fairly predictable to a computer. As we’ve encountered thousands of different situations, we’ve built software models of what to expect, from the likely (a car stopping at a red light) to the unlikely (blowing through it). We still have lots of problems to solve, including teaching the car to drive more streets in Mountain View before we tackle another town, but thousands of situations on city streets that would have stumped us two years ago can now be navigated autonomously.
Our vehicles have now logged nearly 700,000 autonomous miles, and with every passing mile we’re growing more optimistic that we’re heading toward an achievable goal—a vehicle that operates fully without human intervention.
More Mercedes F1 Engine Stuff
Here's more Mercedes F1 Engine stuff I've been finding on websites, mainly Sky and BBC.
Look at the compressor housing embedded in the engine's front casing. For those who don't like to read there's only this video.
Look at the compressor housing embedded in the engine's front casing. For those who don't like to read there's only this video.
Locating the internal combustion engine on a 2014 Formula One car is akin to finding a needle in a hay stack, but beneath all those ducts and coolers there really is a 1600cc V6. This drawing highlights the key elements of the engine packaging and illustrates why maintaining these cars is so much more work than in previous seasons.
1: Where the exhaust's primary pipes meet up into the tail pipe.
2: The connection from the tail pipe to the turbo.
3: With the engine sitting so low in the chassis, Mercedes have included this raised stiffening rib between the front engine-to-chassis mounting and the interface between the engine and gearbox. This helps maximise torsional stiffness, something vitally important to an F1 car's performance, as the cornering loads from the front to rear axles are all fed through the chassis and engine.
4: One of the many coolers required to maintain the temperatures of the hydraulic oil, gearbox oil, engine oil, water, ERS battery pack and control unit and the intercooler for the forced induction system.
5: A small duct that connects to an exit hole in the top of the engine cover, to assist in cooling one of the many components beneath.
6: A further duct and cooler, probably the gearbox cooler based on its size.
7: The connection from the cold side of the turbo to the airbox itself, where the air pressurised by the turbo is fed into the engine.
We’re two races into the Formula 1 season, and Mercedes-Benz has been killing it. Now we know the team’s secret (one of them, anyway), and it’s brilliantly simple.
This year, the entire grid of 22 cars is running 1.6-liter turbocharged V6 engines with a sophisticated hybrid energy system that scavenges energy from the brakes and turbo. F1 engineers are among the sharpest on the planet, and they have thousands of parameters they can tweak and tricks they can use to make these power units as powerful and efficient as possible. Mercedes’ best and brightest found a particularly cool one: they essentially cut the turbo in half.
This is very smart. Here’s why.
A turbocharger’s job is to shove as much air into the engine as possible. An engine is essentially a giant pump, drawing air and fuel to create power and expelling exhaust. More air equals more power, because the more air and fuel you can mix the more shove you get. A turbo, which mounted to the exhaust side of the engine, uses two turbines to increase the volume of air flowing through the engine. One turbine, which is spun by exhaust gases leaving the engine, draws air in. The other compresses fresh air and forces it into the engine’s cylinders, where it mixes with the fuel and explodes, generating power.
It works exceptionally well, but there’s a drawback to the design. The exhaust gases create insane amounts of heat because of the high temperatures of the explosion inside the engine. Heat is bad for power, as the engine is happiest when you feed it the densest, coolest air possible. Putting the turbocharger next to the air intake heats the air going into the engine, robbing you of power. You could move the turbo, but that means more plumbing, less efficiency, and more weight–all bad things when you’re competing at the top tier of motorsport.
What Mercedes’ boffins have done, according to Sky Sports F1 technical guru Mark Hughes, is split the turbo in half, mounting the exhaust turbine at the rear of the engine and the intake turbine at the front. A shaft running through the V of the V6 engine connects the two halves, keeping the hot exhaust gases driving the turbo from heating the cool air it’s drawing into the engine.
Aside from getting cooler air into the engine and extracting more power (maybe as much as 50 horsepower), this setup also allows Mercedes to keep drivetrain components closer to the center of the car. It also allowed the team to use a smaller intercooler, which cools off the heated air before going into the engine, compared to the rest of the cars.
And what about those other cars?
Even with Mercedes’ secret out, there’s not much anyone can do about it. Engine designs are essentially locked down for the season, so the only teams that can benefit from it are the teams using Mercedes-Benz engines. But those teams–McLaren, Williams, and Force India–haven’t been testing these new V6s as long as the official factory team. It’s rumored that Mercedes has been running a version of this engine in secret for almost two years, and even though it supplies engines to other teams, they are, after all, competitors. And now they’re on a steep learning curve as Mercedes continues to dominate the pack.
Mercedes nifty turbo trick is just one of many engineering schemes the teams have come up with to maximize power and boost efficiency. And while it’s an advantage for now, Mercedes can’t rest on its laurels. Each team is finding new ways of exploiting the new engine/hybrid combo, and we’ve yet to see what tricks the other teams have up their sleeves.
From what the BBC said, it wasn't the Engine guys that came up with it, it was the chassis people at Mercedes who asked for the move to happen as it freed up space at the back of the car!
BBC Sport's chief F1 writer Andrew Benson in Bahrain:
"During Friday practice we explained why the Mercedes car is so fast, because of a clever layout of the engine, with the compressor at the front and the turbine at the back, which reduces throttle lag, improves weight and packaging and frees up the electrical parts of the power unit to produce more power at the wheels.
We have a bit more info now on the detail behind that. The key is the better airflow into the compressor, because the air has less far to travel from the inlet. Less pressure loss at the compressor leads to more power than is available from the Ferrari and Renault engines. The interesting thing is that apparently the idea initially came from the chassis team, aware of the potential packaging, weight and weight distribution advantages of splitting the turbine and compressor. The engine team realised it was an enormous technical challenge and were not initially sure whether they could pull it off. But they have, and the results are spectacular."
Sky Sports F1 2014: How Mercedes become so strong in 2014
Finally a very pictorial explanation of how the Mercedes turbocharger layout is so different from other engine suppliers. Brilliant!
Malaysian GP 2014
I won't bother you with details, guess everybody should know by now that Hamilton/Mercedes is on pole. But did you see Vettel and Red Bull at .055 from pole? And that's with Vettel getting the checkered flag when he was out for another fast lap, a rare mistake and lack of timing from Red Bull. OK it was raining you might say, but when Renault overcomes reliability and finds some extra ponies I predict Mercedes will be in trouble soon, the Red Bull chassis seems to tick all the boxes and to be very fast in the turns. The fact they're still running in the top places with a powertrain package that fails to deliver says it all. Damn those flow meters! :)
Four Cylinder Boxster Engines for Porsche
Porsche going back to it's original Beetle roots? Or just the continuing trend of downsizing these days? Expect some kind of forced induction to claim those 400 PS and somehow I smell a special 911 4-Cylinder China version.
This is 6 cylinder engine by the way, but could be a rare sight at Porsche someday.
Here's an article with some more insider information from Autoweek,
This is 6 cylinder engine by the way, but could be a rare sight at Porsche someday.
Here's an article with some more insider information from Autoweek,
Future versions of the Porsche Boxster and Cayman are in line to receive a four-cylinder boxer engine, according to a German media report quoting CEO Matthias Mueller.
In an interview with Germany's Auto Motor und Sportmagazine published on March 20, Mueller said Porsche road cars would follow the lead of the company's hi-tech 919 Hybrid racecar in receiving four-cylinder engines.
But while the 919 Hybrid runs a unique V-4 engine, the unit being readied for the Boxster and Cayman will follow the lead of Porsche's classic six-cylinder with a 180-degree horizontally opposed layout as part of a modular engine strategy.
"We will continue with the downsizing strategy and develop a new four-cylinder boxer engine, which will see service in the next-generation Boxster and Cayman," said Mueller, adding, "we will not separate ourselves from efforts to reduce CO2."
When queried on the output of the new four-cylinder boxer engine, Mueller suggested it would boast "up to 400ps [395 hp]."
Today's 3.4-liter six-cylinder powered Boxster and Cayman models develop up to 325 hp and 335 hp respectively in the new GTS range-topping models revealed last week.
For more coverage, go to the Web site of Autoweek, an affiliate of Automotive News Europe.
BMW F10 (5 series) Powertrain Training Document
Found this while googling some bimmer stuff, you can download it here. The website seems to have some more interesting documents. Well worth a look.
BMW Triple Turbo Diesel (N57S)
This engine just doesn't seize to amaze me and I hope to have the opportunity to have a go at it someday. In the meantime please BMW fit it in a RWD car!!
- Here's an interesting article from Automotive Engineer, lookout for the detail about the cylinder head bolts meeting the main bearing ones.
Sequential boosting is a mature technology now but, when BMW first used it in 2004 to make its straight-six diesel more potent, it marked a step-change in engine development. Connecting one small and one large turbo in series meant that low-end torque and top-end power were both far higher than what the single-turbo 3-litre unit could produce.
Now series- and parallel-sequential boosting systems appear on competitors’ V6 diesels so BMW’s latest offering has been developed to satisfy consumers’ demands for even more power. The solution is a third turbocharger. The company claims this feature is unique and makes this six-cylinder diesel, known in-house as the N57S, the most powerful in the world.
The engine is based on the existing 2,993cc 230kW/630Nm unit, but output has been raised to 280kW and 740Nm – 60Nm more than is achieved by the 4.4-litre gasoline V8 in the high-performance M5. Increasing displacement was not an option – BMW diesels are modular in design and have many shared components – but making everything fit was still tough.
“The first challenge was integrating the technology into the engine and then into the vehicle but our inline layout offers optimum conditions,” says Detlef Hiemesch, BMW’s development manager for diesel engines and exhaust aftertreatment.
“We didn’t modify the bore or stroke because it had to remain part of our engine family – this was a very high priority from the very beginning. So we had to increase robustness to achieve this high specific output – more than 93kW/litre.”
BMW’s engineers had the advantage that they could use the entire right-hand side of the engine to fit in the three turbos, together with a close-coupled oxi-cat and particulate filter housed in the same can. Doing this on a V6 – which has a much shorter block – would be much harder.
The higher ratings meant an increase in peak combustion pressures from 185 to 200bar. Audi and Jaguar diesels use high-strength compacted graphite iron blocks to handle the stresses but BMW’s engine is still all-aluminium. Hiemesch says that cast-iron solutions were considered but would’ve meant that weight targets would be exceeded and would’ve deviated too far from the core design.
So a number of improvements were made instead. A secondary heat treatment process seals any surface porosity in the block castings. Interbore cooling bridges have been improved to help with the thermal loads. But perhaps the most significant change is to the clamping method used for the cylinder head and main bearing caps.
“We had the idea to connect the bolts,” says Hiemesch. “We have a large threaded insert in the crankcase where the cylinder head and main bearing bolts meet. The insert is steel – that’s the key to success.”
The crankshaft and con rods have been strengthened too. The pistons, supplied by Federal Mogul, have remelted crowns to help cope with the high mechanical and thermal loads – the technology is used in Daimler’s V6 diesel too.
Source: ae-plus.com
Now series- and parallel-sequential boosting systems appear on competitors’ V6 diesels so BMW’s latest offering has been developed to satisfy consumers’ demands for even more power. The solution is a third turbocharger. The company claims this feature is unique and makes this six-cylinder diesel, known in-house as the N57S, the most powerful in the world.
The engine is based on the existing 2,993cc 230kW/630Nm unit, but output has been raised to 280kW and 740Nm – 60Nm more than is achieved by the 4.4-litre gasoline V8 in the high-performance M5. Increasing displacement was not an option – BMW diesels are modular in design and have many shared components – but making everything fit was still tough.
“The first challenge was integrating the technology into the engine and then into the vehicle but our inline layout offers optimum conditions,” says Detlef Hiemesch, BMW’s development manager for diesel engines and exhaust aftertreatment.
“We didn’t modify the bore or stroke because it had to remain part of our engine family – this was a very high priority from the very beginning. So we had to increase robustness to achieve this high specific output – more than 93kW/litre.”
BMW’s engineers had the advantage that they could use the entire right-hand side of the engine to fit in the three turbos, together with a close-coupled oxi-cat and particulate filter housed in the same can. Doing this on a V6 – which has a much shorter block – would be much harder.
The higher ratings meant an increase in peak combustion pressures from 185 to 200bar. Audi and Jaguar diesels use high-strength compacted graphite iron blocks to handle the stresses but BMW’s engine is still all-aluminium. Hiemesch says that cast-iron solutions were considered but would’ve meant that weight targets would be exceeded and would’ve deviated too far from the core design.
So a number of improvements were made instead. A secondary heat treatment process seals any surface porosity in the block castings. Interbore cooling bridges have been improved to help with the thermal loads. But perhaps the most significant change is to the clamping method used for the cylinder head and main bearing caps.
“We had the idea to connect the bolts,” says Hiemesch. “We have a large threaded insert in the crankcase where the cylinder head and main bearing bolts meet. The insert is steel – that’s the key to success.”
The crankshaft and con rods have been strengthened too. The pistons, supplied by Federal Mogul, have remelted crowns to help cope with the high mechanical and thermal loads – the technology is used in Daimler’s V6 diesel too.
Source: ae-plus.com
- A nice overview of the turbo chargers from Diesel power magazine but also a bit controversial on the ultimate driving machine thing.
B The larger, low-pressure turbo is located on the bottom and joins in with the smaller turbo located directly above it during medium engine speeds
C When the engine gets higher in the rpm band, the final, small, high-pressure variable geometry turbocharger joins in with the other two
D The Diesel catalytic converter is located close to the engine to take advantage of its heat; the oxidation-type converter oxidises hydrocarbons and carbon monoxide using the oxygen present in the diesel exhaust
E The EGR cooler prepares exhaust gases for reintroduction into the combustion chamber, which limits NOx formation
The Ultimate Driving Machine is a Diesel
The only thing we don’t like about the new BMW N57S triple-turbocharged Diesel engine is that it’s not available in the United States. Although it hasn’t physically reached our shores, the idea of a high-performance diesel that can dominate its gasoline challengers in every measurable way has sent shockwaves through the spark-ignited performance community. After the 127hp/liter diesel bomb went off and the dust settled, some automotive journalists with affection for gasoline engines took offence to the diesel onslaught and tried to downplay its high performance numbers by complaining about its lack of noise and unfamiliar feel. Others, such as former Motor Trend editor Angus Mackenzie, get it. And he offered an opposing view, expressed in a 2011 article titled, “BMW’s Best Six Is…A Diesel.” Perhaps the only ones not shocked by this high-performing diesel are the editors and readers of Diesel Power, who welcomed the news as confirmation of something we already knew.
BMW M Performance Diesel
Engine type: All-aluminum 3.0L diesel I-6
Displacement: 3.0L (2,993 cc)
Bore x Stroke (in.): 3.30 x 3.54
Compression ratio: 16:1
Fuel Delivery: Common-rail direct injection (31,908 psi) (2200 bar for us Europeans)
Aspiration: Triple-turbocharged
Valvetrain: 24-valve DOHC
Mfg.’s hp at rpm: 381 at 4,000
Mfg.’s torque (lb-ft) at rpm: 546 at 2,000 (that's 740 N.m for us Europeans)
Source: www.dieselpowermag.com
- And of course the compulsory video:
991 will be remembered as the hottest Porsche
I still struggle to understand how a big issue like this wasn't picked up by Porsche during testing , I could understand Ferrari or Lamborghini as is my believe they don't do extensive durability testing as other "lesser" OEM's but Porsche?! The new GT3 engine is longer the Metzger engine but an upgraded version of the current direct injection flat-6 you can find in other 991's, was this the reason this problem went under the radar? Porsche believing that the modifications did not require extensive testing and deadlines for launch? Or just plain unlucky? I'm sure we'll never know exactly and this will haunt the boys from Stuttgart for years to come and probably add to those automotive dogmas like the 996 engines. One thing's for sure with the "interweb" at least we're getting loads of details and insight on this issue, you can find loads and updated info on the Pistonheads site.
Also people seem to forget earlier on there was a fire with a 991 prototype in Germany back in 2011, according to the article that car was running an engine specific for the Chinese Market. Related?
Also people seem to forget earlier on there was a fire with a 991 prototype in Germany back in 2011, according to the article that car was running an engine specific for the Chinese Market. Related?
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