Helicopter Crashes While Filming Autonomous Audi 218
telomerewhythere writes "A helicopter commissioned by Audi to film its autonomous Audi TT climbing Pikes Peak crashed early this morning. Four people on board were hurt, the pilot seriously. It's a surreal story — a manned vehicle crashes while the one climbing a mountain driven only by computers and sensors carries on. Here's more on the autonomous Audi, a project undertaken with the help of Stanford University."
Surreal (Score:2, Informative)
No, it's just a clever PR stunt by machines from the future.
Something smells fishy... (Score:2, Informative)
Re:GPS? (Score:2, Informative)
Probably they were using something like that. Something along the lines of an inertial measurement unit (IMU) or similar navigational computer. These things usually combine GPS tracking with a precision gyroscope. They can pretty much fly a plane all by themselves, and the military uses them in land-based vehicles, such as autonomous or semi-autonomous tanks. That they could be used to drive a car is not surprising.
Re:GPS? (Score:5, Informative)
Your $70 GPS addon is way too inaccurate for the kind of autonomous navigation they're trying to achieve. I mean, your standard SiRFstar III claims 2.5 meters of accuracy 50% of the time (a sigma of 3.7 m). That means you can't even be sure whether you're actually on the road, never mind what lane you're in. And that's only in a clear-sky situation. Once you're in a downtown "Urban Canyon" where you hardly pick up any GPS satellites anymore or get wrong readings due to multipath propagation, good luck. Your standard GPS SatNav simply always assumes you're on the road. That won't do for an autonomous vehicle.
You'll need something closer to this high-speed INS+GPS [oxts.com], the better models of which can be accurate in the decimeter range (assuming careful calibration). The ones I know about are all in the US$50,000 and above price range.
Re:Surreal? (Score:2, Informative)
Correction: Un hélicoptère
Physics is a bitch (Score:2, Informative)
The elevation at the crash site: 13,800ft
Service ceiling of the helicopter 11,150ft
The data is taken from Eurocopter AS355F2, the crashed one was a AS355F1.
Re:So the weak point in the system is...... (Score:3, Informative)
Re:Physics is a bitch (Score:4, Informative)
The actual "Service Ceiling" of any aircraft is dependent on the local "Density Altitude" and not the physical elevation of the ground. Depending on the temperature, humidity and other factors, the density altitude of a particular location can be several thousand feet under or above the actual local elevation. The pilot would take that information into account to determine how high they can safely fly the aircraft.
Bill
Re:Condolences (Score:3, Informative)
Correction... while the color scheme looks like their new Bell 212HP... it appears that this is actually an Aerospatiale Astar 355 ("Twinstar") dual turboshaft operated AS350 series aircraft.
E
All helicopter crew released from hospital (Score:5, Informative)
The helicopter crew is out of hospital. [jalopnik.com] All four of them.
Re:The opposite (Score:5, Informative)
Re:Physics is a bitch (Score:4, Informative)
At any point after 8am, the temperature profile looks to be quite a bit above standard atmosphere, meaning density altitudes were higher than pressure altitudes. Barring some unusual atmospheric conditions the density altitude at around 10,000 feet was probably closer to 12,000-14,000 depending on how high the temperature got at the time of the accident. The pilot underestimating the quickly rising temperature may have even been a factor.
If 11,000 feet is in fact the correct value for the service ceiling of the aircraft, I would say this situation was caused by the decision to fly a heavily loaded aircraft outside of its performance envelope.
Re:Physics is a bitch (Score:3, Informative)
Of course, these weather stations all measure temperature at the ground, most around 6000 ft. So let's look at this another way. In order for the air at 13,000 ft to be at a density altitude under 11,000 ft, it'd have to be at about -20 degrees. The normal lapse rate is around 3.5 degrees per 1000 ft. Thus, the expected temperature given 50 degrees at 6000ft is around 25 degrees at 13,000 ft. Unless the lapse rate was more than double the standard atmospheric model, the density altitude places that helicopter above it's service ceiling.
If I had to guess, I'd say that even in the early morning cool temperatures, that aircraft was still being operated in excess of its expected performance.