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VW Raises the Bar for Self-Driving Vehicles
Old Man Kensey writes "According to the UK Daily Mail, VW has produced a prototype Golf (code-named "53 plus 1" in a reference to Herbie the Love Bug) that successfully steers and accelerates itself at speeds up to 150 MPH on tracks designed on the spot without pre-programming. It sounds almost too good to be true given some of the problems CMU's prototype has had over the years, but perhaps VW has learned from and extended CMU's research (and within-an-inch GPS positioning probably helps too)."
I have just read about 53+1 the other day (can't rembember where, tough) 53+1 is specialized on slalom courses and can navigate them faster than a human driver. The car first runs the course very slowly scanning it, then it has to pause for half an hour when a special software optimizes steering, braking and acceleration points and afterwards it goes around the course faster than a real driver could. The system is NOT flexible, for example when a human suddenly is on the track on the fast lap it will blissfully ignore the humans existance and accelerate right through the human and create quite a mess. The usage seems to be exactly repeatable driving for car or tyre development. Froh
Actually - some car-based GPS systems link up to the car's other sensors (accelerometer, speed, steering, parking radar, etc). While they're not accurate for any long distance, they're perfectly good for a short distance (maybe a few hundred metres) and the software in the system can use this info in the temporary absence of a GPS signal.
Well, in summary (I just read the Spiegel article), the car in question first learns the track based on traffic cones. Actually, the only thing this cars knows are traffic cones. A program then runs on the collected data and calculates the "ideal" path. When the finanlly activate the "racing mode", the car "simply" drives the studied track and that *blindly*. There need not to be any traffic cones, and it will not stop if something unexpected happens (so if a rabbit jumps in it's way, the researches will have rabbit for dinner) It does react a bit on the data from the sensors in the racing mode, but it's more for avoiding small variations in the track like a wet spot.
The car itself is pretty much a standard Golf GTI 2.0 Turbo (200HP) and the only thing they changed was stronger braking. They use the default sensors to make the program learn. Also, in the Spiegel article, there is not any mention of GPS.
Oh, and the research isn't intended to make auto-driving cars for you and me. They want to create a way that cars do exactly the same test runs on test-tracks to check the settings of the car. The results would be more reproductible. If anything, this tech is to put test-drivers out of work ;-)
They also mention that some of the tech was derived from a Touareg that they used in a competition of the US Defense Department in the Nevada desert. However, that one had completely different goals.
I'm sorry that I didn't translate the whole thing, but it was just too long.
Ahhh...the great dumpster continuum. Many a free computer will be found there. -- sowth (748135)
I can claim to be a "rocket scientist", at least I have designed systems for satellite control and tracking, and I work for an aerospace company.
You cannot measure a position to within less than a centimeter using GPS. You can design a ranging system that gives you a measurement with enough numbers to represent that precision, but it doesn't mean that you can trust such numbers.
You cannot use GPS to give you better measurements than the accuracy of the GPS constellation orbit determination, and the satellites' positions vary more or less randomly due to residual atmosphere, solar wind, and solar radiation pressure. The end result is that GPS cannot give any reliable measurement to less than 10 cm, and one meter is closer to the best that one can accomplish in practical situations.
A more accurate system than GPS is LAGEOS, which has satellites that are much heavier and smaller than the GPS satellites. They are basically brass balls covered with mirrors. Because of that higher density, LAGEOS satellites suffer less perturbation from non-gravitational solar and atmospheric effects. However, the equipment for doing ranging with LAGEOS satellites is not portable, it's meant for geodesy studies, not navigation.
A good overview of different satellite ranging systems can be found in "Satellite Orbits", by O. Montenbruck and E. Gill, ISBN 3-540-67280-X, and here is a Wikipedia link for the most accurate satellite ranging systems.