Driverless cars, mph and km/h

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KeithW
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Re: Driverless cars, mph and km/h

Post by KeithW » Fri Nov 08, 2019 11:50

JohnnyMo wrote:
Tue Mar 20, 2018 21:37
I assume the car has a GPS system which will know where it is, & what the speed limit was. It will be anticipating changes in the speed limit but on the look out for any new changes.

I assume these will be reported to HQ & then distributed to the rest of the hive.
My car has a camera that reads the speed limit sign and displays it on the dashboard, its up to the driver to know if its 50 mph or 50 kph. The main problem is that it also sees the speed limit signs on the back of trucks so occasionally you get two speed limit signs like 50 and 70 which were actually on the back of a foreign registered HGV !

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Re: Driverless cars, mph and km/h

Post by KeithW » Fri Nov 08, 2019 12:07

AutomaticBeloved wrote:
Fri Nov 08, 2019 09:51
Well it seems Uber's self driving car has massive problems. The report into the Uber vehicle hitting and killing a pedestrian is coming out.

https://arstechnica.com/cars/2019/11/ho ... 018-crash/

"NTSB says the system "did not include consideration for jaywalking pedestrians."

"When the system detects an emergency situation, it initiates action suppression. This is a one-second period during which the [automated driving system] suppresses planned braking while the system verifies the nature of the detected hazard and calculates an alternative path, or vehicle operator takes control of the vehicle."

"Even after this one-second delay, the NTSB says, the system doesn't necessarily apply the brakes with full force. If a collision can be avoided with hard braking, the system brakes hard, up to a fixed maximum level of deceleration. However, if a crash is unavoidable, the system applies less braking force, initiating a "gradual vehicle slowdown," while alerting the driver to take over."

This is quite simply bad software design, flipping between object classifications should simply not reset the object avoidance process and I can only assume the 1 second delay was fitted to suppress false positives. At a minimum the driver should have been alerted and the braking system armed, then if the driver did not react the brakes would be applied as happens with the system fitted to my Ford C-Max. The one drawback is that it does produce some false positives especially on a curved dual carriageway where it can perceive the vehicle in lane 1 as being in my path. As long as I react to the warning the brakes are not applied. The worst aspect of all this that Uber turned off the collision protection system fitted by Volvo that would have applied the brakes if the vehicle was being driven manually.

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ellandback
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Re: Driverless cars, mph and km/h

Post by ellandback » Fri Nov 08, 2019 13:36

I've recently changed my car for one which has speed limit recognition technology and I have to say I don't find it particularly reliable. It often picks up stray 5 MPH speed limit signs in private yards/car parks etc as I pass alongside (but not past) them, or misaligned 20 signs on side roads I'm not actually driving on, and thus displays an incorrect limit.

It usually picks up smart motorway limits as they change from gantry to gantry, but not always. It usually ignores 'bouncing ball' advisories, but sometimes presents them as mandatory limits. It thinks permanent NSL signs mean no limit, but does not recognise electronic smart motorway NSLs at all.

I am still wondering what on earth it managed to see on a country lane in northern Halifax to cause it to tell me that the speed limit there was 120.

EDIT: Apparently that was my 1237th post. A milestone that only a Yorkshire Sabristi would appreciate. :D
Last edited by ellandback on Fri Nov 08, 2019 13:39, edited 1 time in total.

Andy33gmail
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Re: Driverless cars, mph and km/h

Post by Andy33gmail » Fri Nov 08, 2019 13:37

The type of object does affect trajectory though. A pedestrian cannot move at 30mph, a bike cannot move at 70mph etc, so I can see the motivation for dropping previous trajectory calculations, especially if the history of all coordinates (as opposed to results from same) is not persisted long enough

The common sense question would be whether a reasonably competent driver might have the same outcome. 5 seconds is a long time to react, so I imagine not

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Vierwielen
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Re: Driverless cars, mph and km/h

Post by Vierwielen » Fri Nov 08, 2019 14:46

Andy33gmail wrote:
Fri Nov 08, 2019 13:37
A pedestrian cannot move at 30mph,
One evening, a few years ago, when I was working in Germany and had accomodation in the commuter village of Schwalbach-am-Taunus, I went for a walk and was clocked by a speed camara as going at 6 km/h. (... and I did not even get a :) ).

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Vierwielen
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Re: Driverless cars, mph and km/h

Post by Vierwielen » Fri Nov 08, 2019 14:50

Reading wrote:
Thu Mar 29, 2018 12:44
Driverless cars make sense if all vehicles are driverless and you have central control or at least communication between vehicles so they can interact to avoid issues. A system with a mixture of machine (driverless) and human (driven) control where the individual elements (cars/bikes/lorries/traffic lights/emergency services) do not communicate in real time is far far harder, contains many more modes of failure and is a recipe for disaster.
London already has something along those lines. It is called the DLR.

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Re: Driverless cars, mph and km/h

Post by Octaviadriver » Fri Nov 08, 2019 15:01

ellandback wrote:
Fri Nov 08, 2019 13:36
I've recently changed my car for one which has speed limit recognition technology and I have to say I don't find it particularly reliable. It often picks up stray 5 MPH speed limit signs in private yards/car parks etc as I pass alongside (but not past) them, or misaligned 20 signs on side roads I'm not actually driving on, and thus displays an incorrect limit.

It usually picks up smart motorway limits as they change from gantry to gantry, but not always. It usually ignores 'bouncing ball' advisories, but sometimes presents them as mandatory limits. It thinks permanent NSL signs mean no limit, but does not recognise electronic smart motorway NSLs at all.
Mine too has occasional blips and picks up the wrong limit or misses a sign if hidden by traffic etc., but when it sees the NSL sign, it'll show either 60 mph or 70 mph as appropriate. The only time I've ever seen it show the NSL is on the unrestricted sections of German autobahn.

I've noticed it's clever enough to pick up dual limits, such as in built up areas in Poland where the limit is 50 kph or 60 kph from 11pm to 5am and also displays no overtaking signs. It's never seen one in the UK, but has seen plenty abroad.

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ellandback
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Re: Driverless cars, mph and km/h

Post by ellandback » Fri Nov 08, 2019 17:57

Mine does seem to recognise proper :nsl: signs, because if I pass one it immediately cancels whatever limit it was displaying before. It just doesn't show anything in its place.

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Re: Driverless cars, mph and km/h

Post by KeithW » Fri Nov 08, 2019 18:40

Vierwielen wrote:
Fri Nov 08, 2019 14:50
Reading wrote:
Thu Mar 29, 2018 12:44
Driverless cars make sense if all vehicles are driverless and you have central control or at least communication between vehicles so they can interact to avoid issues. A system with a mixture of machine (driverless) and human (driven) control where the individual elements (cars/bikes/lorries/traffic lights/emergency services) do not communicate in real time is far far harder, contains many more modes of failure and is a recipe for disaster.
London already has something along those lines. It is called the DLR.
And on the much earlier Victoria line but this is much easier to in the relatively sterile environment of a railway than on a road.

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Chris Bertram
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Re: Driverless cars, mph and km/h

Post by Chris Bertram » Fri Nov 08, 2019 20:41

KeithW wrote:
Fri Nov 08, 2019 18:40
Vierwielen wrote:
Fri Nov 08, 2019 14:50
Reading wrote:
Thu Mar 29, 2018 12:44
Driverless cars make sense if all vehicles are driverless and you have central control or at least communication between vehicles so they can interact to avoid issues. A system with a mixture of machine (driverless) and human (driven) control where the individual elements (cars/bikes/lorries/traffic lights/emergency services) do not communicate in real time is far far harder, contains many more modes of failure and is a recipe for disaster.
London already has something along those lines. It is called the DLR.
And on the much earlier Victoria line but this is much easier to in the relatively sterile environment of a railway than on a road.
It's true that the Victoria Line was an automatic railway from day 1, but it was never unmanned. The "driver", however, only had to press a "start" button under normal circumstances when the train was ready to leave a station, but if manual mode had to be engaged he would be able to operate the train in this mode. The DLR has normally operated unmanned, hasn't it?
“The quality of any advice anybody has to offer has to be judged against the quality of life they actually lead.” - Douglas Adams.

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Re: Driverless cars, mph and km/h

Post by Chris5156 » Fri Nov 08, 2019 21:46

Chris Bertram wrote:
Fri Nov 08, 2019 20:41
The DLR has normally operated unmanned, hasn't it?
No, all DLR trains are staffed with a "train captain" (yes, really) who operates the doors and who is also capable of manually driving the train. It's not unusual for the train to be driven, especially when there is overcrowding on the platforms, as it enables them to ensure the platform edge is clear as the train pulls into a station.

For what it's worth, the Jubilee, Central and Northern lines are also automated, as is the central section of Thameslink.

For a true unmanned railway you need to go overseas - Paris Metro's ligne 1 is fully automated and totally unstaffed.

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Re: Driverless cars, mph and km/h

Post by AutomaticBeloved » Sat Nov 09, 2019 10:05

The Glasgow subway is also automated with onboard staff, but will be switching to unstaffed trains in the next few years. They had planned to go unstaffed in the 70s modernisation but the tech wasn't ready (I think Lille was the first to get it working in the mid 80s with VAL). The plan is for the new trains to operate with a 'driver' initially while platform edge doors are installed at the stations, once that's complete the trains will be unstaffed. UK Fire regs require the stations to remain staffed though.

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