Let's see how clear I can make this.
Longitudinal position on the track isn't a particular issue. GPS, even single-precision, will give you 'good enough' speed and location information for typical block separation; HA-NDGPS with beacons will give you sufficient information for effective CBTC if you have good communications between the trains and wayside equipment.
The issue is distinguishing trains on different track centers.
I suspect the ultimate solution would be "all of the above."
GPS would provide the position of the front and rear of the train to a certain level of accuracy. Radar verifies the speed (and would be compared to the GPS), and trackside or center of track transponders would provide site specific information, verifying location and identifying the specific track, among other items.
Transponders already are used to track individual cars - look for the little grey device on the sides of the cars. It would not be out of the question to use the information from track transponders in combination with the GPS to confirm specifics and to provide information to on-board PTC systems.
Anyone who has an E-Z-Pay transponder (or other similar toll payment system) knows this can work, even at highway speeds.
Many reefers (and some other cars) are already being tracked via satellite. It may even be possible to parse some of the information provided by those cars into such a system.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
Hmmm, getting an idea...
The reason for using GPS is to be able to know within a few feet where he train is along the line, i.e. how far has the train traveled? This is important to know wehere the train is in respect to fouling points. Due to wheel slippage and wear, counting the number of turns of an axle cannot be relied on to give an exact number for distance traveled. One thought on improving distance measurements is using radar to measure speed and thus distance would drived from integrating the measured speed. To improve accuracy, one could place a series of radar reflectors where the relative spacing between reflectors would be a code for position, e.g. milepost and track number. These could be placed in areas where GPS reception is impossible.
If railroads were easy to automate trouble-free we'd have started with the Times Square Shuttle lo! these many years ago, and NAJPTC wouldn't have been such a colossal laugher.
One major issue is precisely what Erik mentioned: the 'one degree of lateral freedom' often leading to very close track-to-track centers and some uncertainty with fouling points of 'listing' or damaged equipment. As mudchicken and others will confirm, typical GPS location has difficulty distinguishing what track a train is on, which is a reason the QNS&L-style radio transponder separation has trouble on railroads with multiple tracks in service. It's much the same issue as using drones for navigation aids; it makes a good show when shiny and new, but at rainy zero-dark-thirty under heavy cloud, with a few years of typical railroad negligence-posing-as-maintenance on the clock, "things can start to happen" that the AI won't correctly anticipate, or deal with.
charlie hebdo Not sure about V-1s landing without damage.
Not sure about V-1s landing without damage.
That kind of sums up some of my misgivings of the pilotless cargo aircraft... The folks launching the V-1s didn't care if less than 100% made it to the target as long as a significant fraction did.
Aircraft, OTOH, operating in three degrees of freedom space (up/down, left/right, faster/slower) are much less likely to collide than ships operating two degrees of freedom space (port/starboard, faster/slower), an even less likely than cars/trucks with two degrees of freedom (left/right, faster/slower), where one of those degrees (left/right by width of road/lane) is tightly constrained. Trains have one degree of freedom and this require much stricter rules of operation especially considering that stopping distances can be further than line of sight. The one degree of freedom for trains makes automatic train control a much easier proposition where the ROW can be protected.
One objection for pilotless aircraft and it's much stronger for autonomous road vehicles is impairment to the sensors. The 77GHz radars used on vehicles are rendered useless when covered with slush or mud and LIDARs are even more sensitive to slush/dirt. Yet another is that a lot more work needs to be done on the pattern recocognotion routines. An example of the latter is that a consientious human driver will recoginize that a bunch of very young children requires a lot more attention than a similar sized bunch of bushes.
OM: I was living in San Diego when that happened and my oldest sister was 6 blocks away from where the planes hit the ground. Number one problem was that there were two aircraft in roughly the same airspace that were being directed by two diferent facilities, ATC and the Lindergh Field tower. Also note that in-flight collisions are more likely around airports.
Looks like pilotless aircraft should have some sort of balloon detection, thouh a more serious issue for delivery drones is detecting wire - power lines, guy wires, antennas.
Speaking of ATC - the rules with respect to airways defined by LF/MF ranges or VORs seem to have been derived from RR dispatching practice.
Euclid charlie hebdo Railroad mainlines would be the most logical and easiest to safely automate if it weren't for labor contracts. It is true that railroads would be the easiest form or transportation to automate, but for the resistance of Labor. However, management views automation as a way to overcome Labor’s resistance to reducing crew size. That is why they like automation. Automation just sidesteps that issue by eliminating crews. Railroad management abhors some improvements such as ECP brakes, but they seem to be very fond of autonomous freight trains. Management loves autonomous freight trains as much as much as they love monster trains, and for the same reason. Automation will be easy to expedite because manufacturers and vendors of automation see a golden opportunity in marketing these sorts of revolutions to such a big customer as the U.S. railroad system, which is all standardized with the same universal needs. This fantastic marketing push will sweep the industry off its feet with this marketing revolution. It will be the biggest thing since dieselization. But it won’t all be easy. On one hand, railroads don’t suffer the problem of trains needing to sense and react to endless obstacles on their right of way in the same manner that cars and trucks have to on public roads do. However it will be very challenging for autonomous freight trains to navigate through all of operational contingencies just by following a program of operation the way Rio Tinto trains do with the consistency and predictability of their operations. So autonomous trains are likely to require a lot of changes to simplify their operation where it is most congested if they are going to follow a program of automatic operation. Otherwise, if they are just programed, the program will require frequent modification. This will tend to require human intervention, so it will be like the trains are not actually autonomous, but more like remote control.
charlie hebdo Railroad mainlines would be the most logical and easiest to safely automate if it weren't for labor contracts.
Railroad mainlines would be the most logical and easiest to safely automate if it weren't for labor contracts.
Better start checking the quality of the hemp rope you all have been smoking.
Never too old to have a happy childhood!
charlie hebdoNot sure about V-1s landing without damage.
True, but they landed without a pilot, if you can consider falling out of the sky "landing..."
Erik_Magthe V-1 and many airliners are capable of taking off, flying and landing without the pilots needing to touch their controls.
Erik_MagI also wonder how many are familiar with the events of Sep 25, 1978?
(I made the mistake of listening to the PSA flight audio. If you haven't... don't.)
Based on their headquarters, I wonder how many of the people there are former GA employees? I also wonder how many are familiar with the events of Sep 25, 1978?
FWIW, autonomous aircraft go back a long way, with the V-1 and many airliners are capable of taking off, flying and landing without the pilots needing to touch their controls. Pilots are still required for taking over when problems occur (flying into a flock of birds) and avoiding other traffic and obstructions.
charlie hebdoSmall pilotless cargo planes to be based in Dallas...
Here's the contact information if interested:
https://natilus.co/contact/
I for one would like to hear Backshop's brother's take on this, in detail.
Mr. Klepper, it's not as bad as that makes it sound.
Many of the 'true' advantages of level 4 autonomy that are at all cost-effective are currently achievable -- platooned operation terminal-to-terminal over interstates; automated parking assistance at docks; yard unloading and loading on flats with tractors fitting under trailer noses. (See Shadow's owner's comments from early last year; those activities are well within reasonable programming and don't suffer from extreme or emergent traffic or weather difficulties.)
And you will see aviation use of autonomous operation long before you see it on roads -- or on railroads, for that matter. One best use of "AI" is in predictive extension of TCAS out to greater range, with following of a large number of relatively labile tracks. Integrate steerable BRS foils with GPS/GIS for 'optimized touchdown' in emergent conditions. It has been my opinion for some time that this, not 'autonomous buses' or widespread dependence on level 4 "owned vehicles", is the most practical solution for regional transport that lacks the pure volume for HrSR.
Small pilotless cargo planes to be based in Dallas
https://www.fox7austin.com/news/ups-fedex-partner-airline-agrees-to-buy-20-pilotless-cargo-planes-in-134m-deal
Comments appreciated.
Apologies for duplications. In this case I seem to lack the necessary skill to remove duplications without some needed text removed as well.
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Related discussion (MIT Senior-House graduates forum
tree68 Absolutely!!! blue streak 1 Visual clues help in these conditions both for engineers and pilots. Don't forget good old seat of the pants...
Absolutely!!!
blue streak 1 Visual clues help in these conditions both for engineers and pilots.
Don't forget good old seat of the pants...
blue streak 1Visual clues help in these conditions both for engineers and pilots.
Engineers have many variables to deal with. Every trip is different. Not only must he understand the dynamics of the present train but has to be aware of outside happenings. I wonder if the airplane hit Would the robot even know it happened. Or what if a small piece of iron on track might derail the next train? Or his train goes over a cracked rail and passes it but reports same., etc,etc,etc
A pilot uses the auto pilot but has to constantly update the autopilot. Too many changes happen when enroute or sudden weather or even a vvolano? No auto pilot has ever been able to handle gusty weather especially in cross wind conditions.
Visual clues help in these conditions both for engineers and pilots. Robots do not see that well.
Tee hee! Maybe in 30+ years or so. Trains and airliners will become automated long before public road going vehicles. Too many variables involved, too much liability.
tree68 NittanyLion I'm referring to pilot error induced by sensory illusions. Case in point (it's been surmised) - JFK Jr.
NittanyLion I'm referring to pilot error induced by sensory illusions.
Case in point (it's been surmised) - JFK Jr.
I won't comment about JFK Jr but that is what killed Buddy Holly, Ritchie Valens and the Big Bopper. The pilot was barely qualified to fly in CAVU but hoped to make a buck flying in conditions that would challenge experienced pilots.
NittanyLionI'm referring to pilot error induced by sensory illusions.
Backshop NittanyLion Turned out the robot is way better than humans at the flying game too. Wrong. Autopilots take the strain off the pilots during cruise. When something goes wrong, the humans do a better job. The pilots aren't just sitting up there twiddling their thumbs when autopilot is on, either. They are constantly monitoring radio communications, fuel burn, alternate airfields for emergencies, weather reports, etc., etc.
NittanyLion Turned out the robot is way better than humans at the flying game too.
Turned out the robot is way better than humans at the flying game too.
Wrong. Autopilots take the strain off the pilots during cruise. When something goes wrong, the humans do a better job. The pilots aren't just sitting up there twiddling their thumbs when autopilot is on, either. They are constantly monitoring radio communications, fuel burn, alternate airfields for emergencies, weather reports, etc., etc.
I'm fully aware of all of that. I'm referring to pilot error induced by sensory illusions. Humans aren't built to fly. I (as a passenger) suffer greatly from the leans. A gryoscope doesn't.
But when they can't ....
https://www.youtube.com/watch?v=IyYxbiZ1FCQ
Hyundai's betting big on CAV's. However the "drone" is some years off. Some of you may not know. Hyundai builds domestic 53' trailers for our market under the label Hyundai Translead. They're manufactured in Tijuana, Baja California. One application I can see happening for AV's are supplier to plant shorthaul. In my area we have multiple tier 1-3 automotive suppliers that are only on average 15 miles from final assembly plants. There's definitely a market there for this to be the first market AV's penetrate.
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